.. kernel-doc:: drivers/i2c/i2c-boardinfo.c
:functions: i2c_register_board_info
-.. kernel-doc:: drivers/i2c/i2c-core.c
+.. kernel-doc:: drivers/i2c/i2c-core-base.c
:export:
obj-$(CONFIG_I2C_BOARDINFO) += i2c-boardinfo.o
obj-$(CONFIG_I2C) += i2c-core.o
+i2c-core-objs := i2c-core-base.o
+
obj-$(CONFIG_I2C_SMBUS) += i2c-smbus.o
obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o
obj-$(CONFIG_I2C_MUX) += i2c-mux.o
obj-$(CONFIG_I2C_SLAVE_EEPROM) += i2c-slave-eeprom.o
ccflags-$(CONFIG_I2C_DEBUG_CORE) := -DDEBUG
-CFLAGS_i2c-core.o := -Wno-deprecated-declarations
+CFLAGS_i2c-core-base.o := -Wno-deprecated-declarations
*/
/*
- * i2c-core.c always sets the buffer length of
+ * i2c-core always sets the buffer length of
* I2C_FUNC_SMBUS_BLOCK_DATA to 1. The length will
* be adjusted when receiving the first byte.
* Thus we can't stop the transaction here.
--- /dev/null
+/* i2c-core.c - a device driver for the iic-bus interface */
+/* ------------------------------------------------------------------------- */
+/* Copyright (C) 1995-99 Simon G. Vogl
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details. */
+/* ------------------------------------------------------------------------- */
+
+/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
+ All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
+ SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and
+ Jean Delvare <jdelvare@suse.de>
+ Mux support by Rodolfo Giometti <giometti@enneenne.com> and
+ Michael Lawnick <michael.lawnick.ext@nsn.com>
+ OF support is copyright (c) 2008 Jochen Friedrich <jochen@scram.de>
+ (based on a previous patch from Jon Smirl <jonsmirl@gmail.com>) and
+ (c) 2013 Wolfram Sang <wsa@the-dreams.de>
+ I2C ACPI code Copyright (C) 2014 Intel Corp
+ Author: Lan Tianyu <tianyu.lan@intel.com>
+ I2C slave support (c) 2014 by Wolfram Sang <wsa@sang-engineering.com>
+ */
+
+#define pr_fmt(fmt) "i2c-core: " fmt
+
+#include <dt-bindings/i2c/i2c.h>
+#include <linux/uaccess.h>
+#include <linux/acpi.h>
+#include <linux/clk/clk-conf.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/gpio.h>
+#include <linux/hardirq.h>
+#include <linux/i2c.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/irqflags.h>
+#include <linux/jump_label.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/property.h>
+#include <linux/rwsem.h>
+#include <linux/slab.h>
+
+#include "i2c-core.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/i2c.h>
+
+#define I2C_ADDR_OFFSET_TEN_BIT 0xa000
+#define I2C_ADDR_OFFSET_SLAVE 0x1000
+
+#define I2C_ADDR_7BITS_MAX 0x77
+#define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1)
+
+/* core_lock protects i2c_adapter_idr, and guarantees
+ that device detection, deletion of detected devices, and attach_adapter
+ calls are serialized */
+static DEFINE_MUTEX(core_lock);
+static DEFINE_IDR(i2c_adapter_idr);
+
+static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
+
+static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE;
+static bool is_registered;
+
+int i2c_transfer_trace_reg(void)
+{
+ static_key_slow_inc(&i2c_trace_msg);
+ return 0;
+}
+
+void i2c_transfer_trace_unreg(void)
+{
+ static_key_slow_dec(&i2c_trace_msg);
+}
+
+#if defined(CONFIG_ACPI)
+struct i2c_acpi_handler_data {
+ struct acpi_connection_info info;
+ struct i2c_adapter *adapter;
+};
+
+struct gsb_buffer {
+ u8 status;
+ u8 len;
+ union {
+ u16 wdata;
+ u8 bdata;
+ u8 data[0];
+ };
+} __packed;
+
+struct i2c_acpi_lookup {
+ struct i2c_board_info *info;
+ acpi_handle adapter_handle;
+ acpi_handle device_handle;
+ acpi_handle search_handle;
+ int n;
+ int index;
+ u32 speed;
+ u32 min_speed;
+};
+
+static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
+{
+ struct i2c_acpi_lookup *lookup = data;
+ struct i2c_board_info *info = lookup->info;
+ struct acpi_resource_i2c_serialbus *sb;
+ acpi_status status;
+
+ if (info->addr || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+ return 1;
+
+ sb = &ares->data.i2c_serial_bus;
+ if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
+ return 1;
+
+ if (lookup->index != -1 && lookup->n++ != lookup->index)
+ return 1;
+
+ status = acpi_get_handle(lookup->device_handle,
+ sb->resource_source.string_ptr,
+ &lookup->adapter_handle);
+ if (!ACPI_SUCCESS(status))
+ return 1;
+
+ info->addr = sb->slave_address;
+ lookup->speed = sb->connection_speed;
+ if (sb->access_mode == ACPI_I2C_10BIT_MODE)
+ info->flags |= I2C_CLIENT_TEN;
+
+ return 1;
+}
+
+static int i2c_acpi_do_lookup(struct acpi_device *adev,
+ struct i2c_acpi_lookup *lookup)
+{
+ struct i2c_board_info *info = lookup->info;
+ struct list_head resource_list;
+ int ret;
+
+ if (acpi_bus_get_status(adev) || !adev->status.present ||
+ acpi_device_enumerated(adev))
+ return -EINVAL;
+
+ memset(info, 0, sizeof(*info));
+ lookup->device_handle = acpi_device_handle(adev);
+
+ /* Look up for I2cSerialBus resource */
+ INIT_LIST_HEAD(&resource_list);
+ ret = acpi_dev_get_resources(adev, &resource_list,
+ i2c_acpi_fill_info, lookup);
+ acpi_dev_free_resource_list(&resource_list);
+
+ if (ret < 0 || !info->addr)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int i2c_acpi_get_info(struct acpi_device *adev,
+ struct i2c_board_info *info,
+ struct i2c_adapter *adapter,
+ acpi_handle *adapter_handle)
+{
+ struct list_head resource_list;
+ struct resource_entry *entry;
+ struct i2c_acpi_lookup lookup;
+ int ret;
+
+ memset(&lookup, 0, sizeof(lookup));
+ lookup.info = info;
+ lookup.index = -1;
+
+ ret = i2c_acpi_do_lookup(adev, &lookup);
+ if (ret)
+ return ret;
+
+ if (adapter) {
+ /* The adapter must match the one in I2cSerialBus() connector */
+ if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
+ return -ENODEV;
+ } else {
+ struct acpi_device *adapter_adev;
+
+ /* The adapter must be present */
+ if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev))
+ return -ENODEV;
+ if (acpi_bus_get_status(adapter_adev) ||
+ !adapter_adev->status.present)
+ return -ENODEV;
+ }
+
+ info->fwnode = acpi_fwnode_handle(adev);
+ if (adapter_handle)
+ *adapter_handle = lookup.adapter_handle;
+
+ /* Then fill IRQ number if any */
+ INIT_LIST_HEAD(&resource_list);
+ ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
+ if (ret < 0)
+ return -EINVAL;
+
+ resource_list_for_each_entry(entry, &resource_list) {
+ if (resource_type(entry->res) == IORESOURCE_IRQ) {
+ info->irq = entry->res->start;
+ break;
+ }
+ }
+
+ acpi_dev_free_resource_list(&resource_list);
+
+ acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
+ sizeof(info->type));
+
+ return 0;
+}
+
+static void i2c_acpi_register_device(struct i2c_adapter *adapter,
+ struct acpi_device *adev,
+ struct i2c_board_info *info)
+{
+ adev->power.flags.ignore_parent = true;
+ acpi_device_set_enumerated(adev);
+
+ if (!i2c_new_device(adapter, info)) {
+ adev->power.flags.ignore_parent = false;
+ dev_err(&adapter->dev,
+ "failed to add I2C device %s from ACPI\n",
+ dev_name(&adev->dev));
+ }
+}
+
+static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
+ void *data, void **return_value)
+{
+ struct i2c_adapter *adapter = data;
+ struct acpi_device *adev;
+ struct i2c_board_info info;
+
+ if (acpi_bus_get_device(handle, &adev))
+ return AE_OK;
+
+ if (i2c_acpi_get_info(adev, &info, adapter, NULL))
+ return AE_OK;
+
+ i2c_acpi_register_device(adapter, adev, &info);
+
+ return AE_OK;
+}
+
+#define I2C_ACPI_MAX_SCAN_DEPTH 32
+
+/**
+ * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter
+ * @adap: pointer to adapter
+ *
+ * Enumerate all I2C slave devices behind this adapter by walking the ACPI
+ * namespace. When a device is found it will be added to the Linux device
+ * model and bound to the corresponding ACPI handle.
+ */
+static void i2c_acpi_register_devices(struct i2c_adapter *adap)
+{
+ acpi_status status;
+
+ if (!has_acpi_companion(&adap->dev))
+ return;
+
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ I2C_ACPI_MAX_SCAN_DEPTH,
+ i2c_acpi_add_device, NULL,
+ adap, NULL);
+ if (ACPI_FAILURE(status))
+ dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
+}
+
+static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
+ void *data, void **return_value)
+{
+ struct i2c_acpi_lookup *lookup = data;
+ struct acpi_device *adev;
+
+ if (acpi_bus_get_device(handle, &adev))
+ return AE_OK;
+
+ if (i2c_acpi_do_lookup(adev, lookup))
+ return AE_OK;
+
+ if (lookup->search_handle != lookup->adapter_handle)
+ return AE_OK;
+
+ if (lookup->speed <= lookup->min_speed)
+ lookup->min_speed = lookup->speed;
+
+ return AE_OK;
+}
+
+/**
+ * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
+ * @dev: The device owning the bus
+ *
+ * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
+ * devices connected to this bus and use the speed of slowest device.
+ *
+ * Returns the speed in Hz or zero
+ */
+u32 i2c_acpi_find_bus_speed(struct device *dev)
+{
+ struct i2c_acpi_lookup lookup;
+ struct i2c_board_info dummy;
+ acpi_status status;
+
+ if (!has_acpi_companion(dev))
+ return 0;
+
+ memset(&lookup, 0, sizeof(lookup));
+ lookup.search_handle = ACPI_HANDLE(dev);
+ lookup.min_speed = UINT_MAX;
+ lookup.info = &dummy;
+ lookup.index = -1;
+
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ I2C_ACPI_MAX_SCAN_DEPTH,
+ i2c_acpi_lookup_speed, NULL,
+ &lookup, NULL);
+
+ if (ACPI_FAILURE(status)) {
+ dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
+ return 0;
+ }
+
+ return lookup.min_speed != UINT_MAX ? lookup.min_speed : 0;
+}
+EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
+
+static int i2c_acpi_match_adapter(struct device *dev, void *data)
+{
+ struct i2c_adapter *adapter = i2c_verify_adapter(dev);
+
+ if (!adapter)
+ return 0;
+
+ return ACPI_HANDLE(dev) == (acpi_handle)data;
+}
+
+static int i2c_acpi_match_device(struct device *dev, void *data)
+{
+ return ACPI_COMPANION(dev) == data;
+}
+
+static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
+{
+ struct device *dev;
+
+ dev = bus_find_device(&i2c_bus_type, NULL, handle,
+ i2c_acpi_match_adapter);
+ return dev ? i2c_verify_adapter(dev) : NULL;
+}
+
+static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
+{
+ struct device *dev;
+
+ dev = bus_find_device(&i2c_bus_type, NULL, adev, i2c_acpi_match_device);
+ return dev ? i2c_verify_client(dev) : NULL;
+}
+
+static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
+ void *arg)
+{
+ struct acpi_device *adev = arg;
+ struct i2c_board_info info;
+ acpi_handle adapter_handle;
+ struct i2c_adapter *adapter;
+ struct i2c_client *client;
+
+ switch (value) {
+ case ACPI_RECONFIG_DEVICE_ADD:
+ if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
+ break;
+
+ adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
+ if (!adapter)
+ break;
+
+ i2c_acpi_register_device(adapter, adev, &info);
+ break;
+ case ACPI_RECONFIG_DEVICE_REMOVE:
+ if (!acpi_device_enumerated(adev))
+ break;
+
+ client = i2c_acpi_find_client_by_adev(adev);
+ if (!client)
+ break;
+
+ i2c_unregister_device(client);
+ put_device(&client->dev);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block i2c_acpi_notifier = {
+ .notifier_call = i2c_acpi_notify,
+};
+
+/**
+ * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
+ * @dev: Device owning the ACPI resources to get the client from
+ * @index: Index of ACPI resource to get
+ * @info: describes the I2C device; note this is modified (addr gets set)
+ * Context: can sleep
+ *
+ * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
+ * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
+ * resources, in that case this function can be used to create an i2c-client
+ * for other I2cSerialBus resources in the Current Resource Settings table.
+ *
+ * Also see i2c_new_device, which this function calls to create the i2c-client.
+ *
+ * Returns a pointer to the new i2c-client, or NULL if the adapter is not found.
+ */
+struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
+ struct i2c_board_info *info)
+{
+ struct i2c_acpi_lookup lookup;
+ struct i2c_adapter *adapter;
+ struct acpi_device *adev;
+ LIST_HEAD(resource_list);
+ int ret;
+
+ adev = ACPI_COMPANION(dev);
+ if (!adev)
+ return NULL;
+
+ memset(&lookup, 0, sizeof(lookup));
+ lookup.info = info;
+ lookup.device_handle = acpi_device_handle(adev);
+ lookup.index = index;
+
+ ret = acpi_dev_get_resources(adev, &resource_list,
+ i2c_acpi_fill_info, &lookup);
+ acpi_dev_free_resource_list(&resource_list);
+
+ if (ret < 0 || !info->addr)
+ return NULL;
+
+ adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
+ if (!adapter)
+ return NULL;
+
+ return i2c_new_device(adapter, info);
+}
+EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
+#else /* CONFIG_ACPI */
+static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
+extern struct notifier_block i2c_acpi_notifier;
+#endif /* CONFIG_ACPI */
+
+#ifdef CONFIG_ACPI_I2C_OPREGION
+static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
+ u8 cmd, u8 *data, u8 data_len)
+{
+
+ struct i2c_msg msgs[2];
+ int ret;
+ u8 *buffer;
+
+ buffer = kzalloc(data_len, GFP_KERNEL);
+ if (!buffer)
+ return AE_NO_MEMORY;
+
+ msgs[0].addr = client->addr;
+ msgs[0].flags = client->flags;
+ msgs[0].len = 1;
+ msgs[0].buf = &cmd;
+
+ msgs[1].addr = client->addr;
+ msgs[1].flags = client->flags | I2C_M_RD;
+ msgs[1].len = data_len;
+ msgs[1].buf = buffer;
+
+ ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+ if (ret < 0)
+ dev_err(&client->adapter->dev, "i2c read failed\n");
+ else
+ memcpy(data, buffer, data_len);
+
+ kfree(buffer);
+ return ret;
+}
+
+static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
+ u8 cmd, u8 *data, u8 data_len)
+{
+
+ struct i2c_msg msgs[1];
+ u8 *buffer;
+ int ret = AE_OK;
+
+ buffer = kzalloc(data_len + 1, GFP_KERNEL);
+ if (!buffer)
+ return AE_NO_MEMORY;
+
+ buffer[0] = cmd;
+ memcpy(buffer + 1, data, data_len);
+
+ msgs[0].addr = client->addr;
+ msgs[0].flags = client->flags;
+ msgs[0].len = data_len + 1;
+ msgs[0].buf = buffer;
+
+ ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+ if (ret < 0)
+ dev_err(&client->adapter->dev, "i2c write failed\n");
+
+ kfree(buffer);
+ return ret;
+}
+
+static acpi_status
+i2c_acpi_space_handler(u32 function, acpi_physical_address command,
+ u32 bits, u64 *value64,
+ void *handler_context, void *region_context)
+{
+ struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
+ struct i2c_acpi_handler_data *data = handler_context;
+ struct acpi_connection_info *info = &data->info;
+ struct acpi_resource_i2c_serialbus *sb;
+ struct i2c_adapter *adapter = data->adapter;
+ struct i2c_client *client;
+ struct acpi_resource *ares;
+ u32 accessor_type = function >> 16;
+ u8 action = function & ACPI_IO_MASK;
+ acpi_status ret;
+ int status;
+
+ ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
+ if (ACPI_FAILURE(ret))
+ return ret;
+
+ client = kzalloc(sizeof(*client), GFP_KERNEL);
+ if (!client) {
+ ret = AE_NO_MEMORY;
+ goto err;
+ }
+
+ if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) {
+ ret = AE_BAD_PARAMETER;
+ goto err;
+ }
+
+ sb = &ares->data.i2c_serial_bus;
+ if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) {
+ ret = AE_BAD_PARAMETER;
+ goto err;
+ }
+
+ client->adapter = adapter;
+ client->addr = sb->slave_address;
+
+ if (sb->access_mode == ACPI_I2C_10BIT_MODE)
+ client->flags |= I2C_CLIENT_TEN;
+
+ switch (accessor_type) {
+ case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
+ if (action == ACPI_READ) {
+ status = i2c_smbus_read_byte(client);
+ if (status >= 0) {
+ gsb->bdata = status;
+ status = 0;
+ }
+ } else {
+ status = i2c_smbus_write_byte(client, gsb->bdata);
+ }
+ break;
+
+ case ACPI_GSB_ACCESS_ATTRIB_BYTE:
+ if (action == ACPI_READ) {
+ status = i2c_smbus_read_byte_data(client, command);
+ if (status >= 0) {
+ gsb->bdata = status;
+ status = 0;
+ }
+ } else {
+ status = i2c_smbus_write_byte_data(client, command,
+ gsb->bdata);
+ }
+ break;
+
+ case ACPI_GSB_ACCESS_ATTRIB_WORD:
+ if (action == ACPI_READ) {
+ status = i2c_smbus_read_word_data(client, command);
+ if (status >= 0) {
+ gsb->wdata = status;
+ status = 0;
+ }
+ } else {
+ status = i2c_smbus_write_word_data(client, command,
+ gsb->wdata);
+ }
+ break;
+
+ case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
+ if (action == ACPI_READ) {
+ status = i2c_smbus_read_block_data(client, command,
+ gsb->data);
+ if (status >= 0) {
+ gsb->len = status;
+ status = 0;
+ }
+ } else {
+ status = i2c_smbus_write_block_data(client, command,
+ gsb->len, gsb->data);
+ }
+ break;
+
+ case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
+ if (action == ACPI_READ) {
+ status = acpi_gsb_i2c_read_bytes(client, command,
+ gsb->data, info->access_length);
+ if (status > 0)
+ status = 0;
+ } else {
+ status = acpi_gsb_i2c_write_bytes(client, command,
+ gsb->data, info->access_length);
+ }
+ break;
+
+ default:
+ dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
+ accessor_type, client->addr);
+ ret = AE_BAD_PARAMETER;
+ goto err;
+ }
+
+ gsb->status = status;
+
+ err:
+ kfree(client);
+ ACPI_FREE(ares);
+ return ret;
+}
+
+
+static int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
+{
+ acpi_handle handle;
+ struct i2c_acpi_handler_data *data;
+ acpi_status status;
+
+ if (!adapter->dev.parent)
+ return -ENODEV;
+
+ handle = ACPI_HANDLE(adapter->dev.parent);
+
+ if (!handle)
+ return -ENODEV;
+
+ data = kzalloc(sizeof(struct i2c_acpi_handler_data),
+ GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->adapter = adapter;
+ status = acpi_bus_attach_private_data(handle, (void *)data);
+ if (ACPI_FAILURE(status)) {
+ kfree(data);
+ return -ENOMEM;
+ }
+
+ status = acpi_install_address_space_handler(handle,
+ ACPI_ADR_SPACE_GSBUS,
+ &i2c_acpi_space_handler,
+ NULL,
+ data);
+ if (ACPI_FAILURE(status)) {
+ dev_err(&adapter->dev, "Error installing i2c space handler\n");
+ acpi_bus_detach_private_data(handle);
+ kfree(data);
+ return -ENOMEM;
+ }
+
+ acpi_walk_dep_device_list(handle);
+ return 0;
+}
+
+static void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
+{
+ acpi_handle handle;
+ struct i2c_acpi_handler_data *data;
+ acpi_status status;
+
+ if (!adapter->dev.parent)
+ return;
+
+ handle = ACPI_HANDLE(adapter->dev.parent);
+
+ if (!handle)
+ return;
+
+ acpi_remove_address_space_handler(handle,
+ ACPI_ADR_SPACE_GSBUS,
+ &i2c_acpi_space_handler);
+
+ status = acpi_bus_get_private_data(handle, (void **)&data);
+ if (ACPI_SUCCESS(status))
+ kfree(data);
+
+ acpi_bus_detach_private_data(handle);
+}
+#else /* CONFIG_ACPI_I2C_OPREGION */
+static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
+{ }
+
+static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
+{ return 0; }
+#endif /* CONFIG_ACPI_I2C_OPREGION */
+
+/* ------------------------------------------------------------------------- */
+
+const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
+ const struct i2c_client *client)
+{
+ if (!(id && client))
+ return NULL;
+
+ while (id->name[0]) {
+ if (strcmp(client->name, id->name) == 0)
+ return id;
+ id++;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(i2c_match_id);
+
+static int i2c_device_match(struct device *dev, struct device_driver *drv)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ struct i2c_driver *driver;
+
+
+ /* Attempt an OF style match */
+ if (i2c_of_match_device(drv->of_match_table, client))
+ return 1;
+
+ /* Then ACPI style match */
+ if (acpi_driver_match_device(dev, drv))
+ return 1;
+
+ driver = to_i2c_driver(drv);
+
+ /* Finally an I2C match */
+ if (i2c_match_id(driver->id_table, client))
+ return 1;
+
+ return 0;
+}
+
+static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ int rc;
+
+ rc = acpi_device_uevent_modalias(dev, env);
+ if (rc != -ENODEV)
+ return rc;
+
+ return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name);
+}
+
+/* i2c bus recovery routines */
+static int get_scl_gpio_value(struct i2c_adapter *adap)
+{
+ return gpio_get_value(adap->bus_recovery_info->scl_gpio);
+}
+
+static void set_scl_gpio_value(struct i2c_adapter *adap, int val)
+{
+ gpio_set_value(adap->bus_recovery_info->scl_gpio, val);
+}
+
+static int get_sda_gpio_value(struct i2c_adapter *adap)
+{
+ return gpio_get_value(adap->bus_recovery_info->sda_gpio);
+}
+
+static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap)
+{
+ struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+ struct device *dev = &adap->dev;
+ int ret = 0;
+
+ ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN |
+ GPIOF_OUT_INIT_HIGH, "i2c-scl");
+ if (ret) {
+ dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio);
+ return ret;
+ }
+
+ if (bri->get_sda) {
+ if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) {
+ /* work without SDA polling */
+ dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n",
+ bri->sda_gpio);
+ bri->get_sda = NULL;
+ }
+ }
+
+ return ret;
+}
+
+static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap)
+{
+ struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+
+ if (bri->get_sda)
+ gpio_free(bri->sda_gpio);
+
+ gpio_free(bri->scl_gpio);
+}
+
+/*
+ * We are generating clock pulses. ndelay() determines durating of clk pulses.
+ * We will generate clock with rate 100 KHz and so duration of both clock levels
+ * is: delay in ns = (10^6 / 100) / 2
+ */
+#define RECOVERY_NDELAY 5000
+#define RECOVERY_CLK_CNT 9
+
+static int i2c_generic_recovery(struct i2c_adapter *adap)
+{
+ struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+ int i = 0, val = 1, ret = 0;
+
+ if (bri->prepare_recovery)
+ bri->prepare_recovery(adap);
+
+ bri->set_scl(adap, val);
+ ndelay(RECOVERY_NDELAY);
+
+ /*
+ * By this time SCL is high, as we need to give 9 falling-rising edges
+ */
+ while (i++ < RECOVERY_CLK_CNT * 2) {
+ if (val) {
+ /* Break if SDA is high */
+ if (bri->get_sda && bri->get_sda(adap))
+ break;
+ /* SCL shouldn't be low here */
+ if (!bri->get_scl(adap)) {
+ dev_err(&adap->dev,
+ "SCL is stuck low, exit recovery\n");
+ ret = -EBUSY;
+ break;
+ }
+ }
+
+ val = !val;
+ bri->set_scl(adap, val);
+ ndelay(RECOVERY_NDELAY);
+ }
+
+ if (bri->unprepare_recovery)
+ bri->unprepare_recovery(adap);
+
+ return ret;
+}
+
+int i2c_generic_scl_recovery(struct i2c_adapter *adap)
+{
+ return i2c_generic_recovery(adap);
+}
+EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
+
+int i2c_generic_gpio_recovery(struct i2c_adapter *adap)
+{
+ int ret;
+
+ ret = i2c_get_gpios_for_recovery(adap);
+ if (ret)
+ return ret;
+
+ ret = i2c_generic_recovery(adap);
+ i2c_put_gpios_for_recovery(adap);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(i2c_generic_gpio_recovery);
+
+int i2c_recover_bus(struct i2c_adapter *adap)
+{
+ if (!adap->bus_recovery_info)
+ return -EOPNOTSUPP;
+
+ dev_dbg(&adap->dev, "Trying i2c bus recovery\n");
+ return adap->bus_recovery_info->recover_bus(adap);
+}
+EXPORT_SYMBOL_GPL(i2c_recover_bus);
+
+static void i2c_init_recovery(struct i2c_adapter *adap)
+{
+ struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+ char *err_str;
+
+ if (!bri)
+ return;
+
+ if (!bri->recover_bus) {
+ err_str = "no recover_bus() found";
+ goto err;
+ }
+
+ /* Generic GPIO recovery */
+ if (bri->recover_bus == i2c_generic_gpio_recovery) {
+ if (!gpio_is_valid(bri->scl_gpio)) {
+ err_str = "invalid SCL gpio";
+ goto err;
+ }
+
+ if (gpio_is_valid(bri->sda_gpio))
+ bri->get_sda = get_sda_gpio_value;
+ else
+ bri->get_sda = NULL;
+
+ bri->get_scl = get_scl_gpio_value;
+ bri->set_scl = set_scl_gpio_value;
+ } else if (bri->recover_bus == i2c_generic_scl_recovery) {
+ /* Generic SCL recovery */
+ if (!bri->set_scl || !bri->get_scl) {
+ err_str = "no {get|set}_scl() found";
+ goto err;
+ }
+ }
+
+ return;
+ err:
+ dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
+ adap->bus_recovery_info = NULL;
+}
+
+static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)
+{
+ struct i2c_adapter *adap = client->adapter;
+ unsigned int irq;
+
+ if (!adap->host_notify_domain)
+ return -ENXIO;
+
+ if (client->flags & I2C_CLIENT_TEN)
+ return -EINVAL;
+
+ irq = irq_find_mapping(adap->host_notify_domain, client->addr);
+ if (!irq)
+ irq = irq_create_mapping(adap->host_notify_domain,
+ client->addr);
+
+ return irq > 0 ? irq : -ENXIO;
+}
+
+static int i2c_device_probe(struct device *dev)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ struct i2c_driver *driver;
+ int status;
+
+ if (!client)
+ return 0;
+
+ driver = to_i2c_driver(dev->driver);
+
+ if (!client->irq && !driver->disable_i2c_core_irq_mapping) {
+ int irq = -ENOENT;
+
+ if (client->flags & I2C_CLIENT_HOST_NOTIFY) {
+ dev_dbg(dev, "Using Host Notify IRQ\n");
+ irq = i2c_smbus_host_notify_to_irq(client);
+ } else if (dev->of_node) {
+ irq = of_irq_get_byname(dev->of_node, "irq");
+ if (irq == -EINVAL || irq == -ENODATA)
+ irq = of_irq_get(dev->of_node, 0);
+ } else if (ACPI_COMPANION(dev)) {
+ irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
+ }
+ if (irq == -EPROBE_DEFER)
+ return irq;
+
+ if (irq < 0)
+ irq = 0;
+
+ client->irq = irq;
+ }
+
+ /*
+ * An I2C ID table is not mandatory, if and only if, a suitable Device
+ * Tree match table entry is supplied for the probing device.
+ */
+ if (!driver->id_table &&
+ !i2c_of_match_device(dev->driver->of_match_table, client))
+ return -ENODEV;
+
+ if (client->flags & I2C_CLIENT_WAKE) {
+ int wakeirq = -ENOENT;
+
+ if (dev->of_node) {
+ wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
+ if (wakeirq == -EPROBE_DEFER)
+ return wakeirq;
+ }
+
+ device_init_wakeup(&client->dev, true);
+
+ if (wakeirq > 0 && wakeirq != client->irq)
+ status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);
+ else if (client->irq > 0)
+ status = dev_pm_set_wake_irq(dev, client->irq);
+ else
+ status = 0;
+
+ if (status)
+ dev_warn(&client->dev, "failed to set up wakeup irq\n");
+ }
+
+ dev_dbg(dev, "probe\n");
+
+ status = of_clk_set_defaults(dev->of_node, false);
+ if (status < 0)
+ goto err_clear_wakeup_irq;
+
+ status = dev_pm_domain_attach(&client->dev, true);
+ if (status == -EPROBE_DEFER)
+ goto err_clear_wakeup_irq;
+
+ /*
+ * When there are no more users of probe(),
+ * rename probe_new to probe.
+ */
+ if (driver->probe_new)
+ status = driver->probe_new(client);
+ else if (driver->probe)
+ status = driver->probe(client,
+ i2c_match_id(driver->id_table, client));
+ else
+ status = -EINVAL;
+
+ if (status)
+ goto err_detach_pm_domain;
+
+ return 0;
+
+err_detach_pm_domain:
+ dev_pm_domain_detach(&client->dev, true);
+err_clear_wakeup_irq:
+ dev_pm_clear_wake_irq(&client->dev);
+ device_init_wakeup(&client->dev, false);
+ return status;
+}
+
+static int i2c_device_remove(struct device *dev)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ struct i2c_driver *driver;
+ int status = 0;
+
+ if (!client || !dev->driver)
+ return 0;
+
+ driver = to_i2c_driver(dev->driver);
+ if (driver->remove) {
+ dev_dbg(dev, "remove\n");
+ status = driver->remove(client);
+ }
+
+ dev_pm_domain_detach(&client->dev, true);
+
+ dev_pm_clear_wake_irq(&client->dev);
+ device_init_wakeup(&client->dev, false);
+
+ return status;
+}
+
+static void i2c_device_shutdown(struct device *dev)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ struct i2c_driver *driver;
+
+ if (!client || !dev->driver)
+ return;
+ driver = to_i2c_driver(dev->driver);
+ if (driver->shutdown)
+ driver->shutdown(client);
+}
+
+static void i2c_client_dev_release(struct device *dev)
+{
+ kfree(to_i2c_client(dev));
+}
+
+static ssize_t
+show_name(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
+ to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
+}
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+static ssize_t
+show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ int len;
+
+ len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
+ if (len != -ENODEV)
+ return len;
+
+ return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
+}
+static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
+
+static struct attribute *i2c_dev_attrs[] = {
+ &dev_attr_name.attr,
+ /* modalias helps coldplug: modprobe $(cat .../modalias) */
+ &dev_attr_modalias.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(i2c_dev);
+
+struct bus_type i2c_bus_type = {
+ .name = "i2c",
+ .match = i2c_device_match,
+ .probe = i2c_device_probe,
+ .remove = i2c_device_remove,
+ .shutdown = i2c_device_shutdown,
+};
+EXPORT_SYMBOL_GPL(i2c_bus_type);
+
+struct device_type i2c_client_type = {
+ .groups = i2c_dev_groups,
+ .uevent = i2c_device_uevent,
+ .release = i2c_client_dev_release,
+};
+EXPORT_SYMBOL_GPL(i2c_client_type);
+
+
+/**
+ * i2c_verify_client - return parameter as i2c_client, or NULL
+ * @dev: device, probably from some driver model iterator
+ *
+ * When traversing the driver model tree, perhaps using driver model
+ * iterators like @device_for_each_child(), you can't assume very much
+ * about the nodes you find. Use this function to avoid oopses caused
+ * by wrongly treating some non-I2C device as an i2c_client.
+ */
+struct i2c_client *i2c_verify_client(struct device *dev)
+{
+ return (dev->type == &i2c_client_type)
+ ? to_i2c_client(dev)
+ : NULL;
+}
+EXPORT_SYMBOL(i2c_verify_client);
+
+
+/* Return a unique address which takes the flags of the client into account */
+static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)
+{
+ unsigned short addr = client->addr;
+
+ /* For some client flags, add an arbitrary offset to avoid collisions */
+ if (client->flags & I2C_CLIENT_TEN)
+ addr |= I2C_ADDR_OFFSET_TEN_BIT;
+
+ if (client->flags & I2C_CLIENT_SLAVE)
+ addr |= I2C_ADDR_OFFSET_SLAVE;
+
+ return addr;
+}
+
+/* This is a permissive address validity check, I2C address map constraints
+ * are purposely not enforced, except for the general call address. */
+static int i2c_check_addr_validity(unsigned addr, unsigned short flags)
+{
+ if (flags & I2C_CLIENT_TEN) {
+ /* 10-bit address, all values are valid */
+ if (addr > 0x3ff)
+ return -EINVAL;
+ } else {
+ /* 7-bit address, reject the general call address */
+ if (addr == 0x00 || addr > 0x7f)
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/* And this is a strict address validity check, used when probing. If a
+ * device uses a reserved address, then it shouldn't be probed. 7-bit
+ * addressing is assumed, 10-bit address devices are rare and should be
+ * explicitly enumerated. */
+static int i2c_check_7bit_addr_validity_strict(unsigned short addr)
+{
+ /*
+ * Reserved addresses per I2C specification:
+ * 0x00 General call address / START byte
+ * 0x01 CBUS address
+ * 0x02 Reserved for different bus format
+ * 0x03 Reserved for future purposes
+ * 0x04-0x07 Hs-mode master code
+ * 0x78-0x7b 10-bit slave addressing
+ * 0x7c-0x7f Reserved for future purposes
+ */
+ if (addr < 0x08 || addr > 0x77)
+ return -EINVAL;
+ return 0;
+}
+
+static int __i2c_check_addr_busy(struct device *dev, void *addrp)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ int addr = *(int *)addrp;
+
+ if (client && i2c_encode_flags_to_addr(client) == addr)
+ return -EBUSY;
+ return 0;
+}
+
+/* walk up mux tree */
+static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
+{
+ struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+ int result;
+
+ result = device_for_each_child(&adapter->dev, &addr,
+ __i2c_check_addr_busy);
+
+ if (!result && parent)
+ result = i2c_check_mux_parents(parent, addr);
+
+ return result;
+}
+
+/* recurse down mux tree */
+static int i2c_check_mux_children(struct device *dev, void *addrp)
+{
+ int result;
+
+ if (dev->type == &i2c_adapter_type)
+ result = device_for_each_child(dev, addrp,
+ i2c_check_mux_children);
+ else
+ result = __i2c_check_addr_busy(dev, addrp);
+
+ return result;
+}
+
+static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
+{
+ struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+ int result = 0;
+
+ if (parent)
+ result = i2c_check_mux_parents(parent, addr);
+
+ if (!result)
+ result = device_for_each_child(&adapter->dev, &addr,
+ i2c_check_mux_children);
+
+ return result;
+}
+
+/**
+ * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
+ * locks only this branch in the adapter tree
+ */
+static void i2c_adapter_lock_bus(struct i2c_adapter *adapter,
+ unsigned int flags)
+{
+ rt_mutex_lock(&adapter->bus_lock);
+}
+
+/**
+ * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT
+ * trylocks only this branch in the adapter tree
+ */
+static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter,
+ unsigned int flags)
+{
+ return rt_mutex_trylock(&adapter->bus_lock);
+}
+
+/**
+ * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
+ * unlocks only this branch in the adapter tree
+ */
+static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,
+ unsigned int flags)
+{
+ rt_mutex_unlock(&adapter->bus_lock);
+}
+
+static void i2c_dev_set_name(struct i2c_adapter *adap,
+ struct i2c_client *client)
+{
+ struct acpi_device *adev = ACPI_COMPANION(&client->dev);
+
+ if (adev) {
+ dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));
+ return;
+ }
+
+ dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
+ i2c_encode_flags_to_addr(client));
+}
+
+static int i2c_dev_irq_from_resources(const struct resource *resources,
+ unsigned int num_resources)
+{
+ struct irq_data *irqd;
+ int i;
+
+ for (i = 0; i < num_resources; i++) {
+ const struct resource *r = &resources[i];
+
+ if (resource_type(r) != IORESOURCE_IRQ)
+ continue;
+
+ if (r->flags & IORESOURCE_BITS) {
+ irqd = irq_get_irq_data(r->start);
+ if (!irqd)
+ break;
+
+ irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
+ }
+
+ return r->start;
+ }
+
+ return 0;
+}
+
+/**
+ * i2c_new_device - instantiate an i2c device
+ * @adap: the adapter managing the device
+ * @info: describes one I2C device; bus_num is ignored
+ * Context: can sleep
+ *
+ * Create an i2c device. Binding is handled through driver model
+ * probe()/remove() methods. A driver may be bound to this device when we
+ * return from this function, or any later moment (e.g. maybe hotplugging will
+ * load the driver module). This call is not appropriate for use by mainboard
+ * initialization logic, which usually runs during an arch_initcall() long
+ * before any i2c_adapter could exist.
+ *
+ * This returns the new i2c client, which may be saved for later use with
+ * i2c_unregister_device(); or NULL to indicate an error.
+ */
+struct i2c_client *
+i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
+{
+ struct i2c_client *client;
+ int status;
+
+ client = kzalloc(sizeof *client, GFP_KERNEL);
+ if (!client)
+ return NULL;
+
+ client->adapter = adap;
+
+ client->dev.platform_data = info->platform_data;
+
+ if (info->archdata)
+ client->dev.archdata = *info->archdata;
+
+ client->flags = info->flags;
+ client->addr = info->addr;
+
+ client->irq = info->irq;
+ if (!client->irq)
+ client->irq = i2c_dev_irq_from_resources(info->resources,
+ info->num_resources);
+
+ strlcpy(client->name, info->type, sizeof(client->name));
+
+ status = i2c_check_addr_validity(client->addr, client->flags);
+ if (status) {
+ dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n",
+ client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr);
+ goto out_err_silent;
+ }
+
+ /* Check for address business */
+ status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
+ if (status)
+ goto out_err;
+
+ client->dev.parent = &client->adapter->dev;
+ client->dev.bus = &i2c_bus_type;
+ client->dev.type = &i2c_client_type;
+ client->dev.of_node = info->of_node;
+ client->dev.fwnode = info->fwnode;
+
+ i2c_dev_set_name(adap, client);
+
+ if (info->properties) {
+ status = device_add_properties(&client->dev, info->properties);
+ if (status) {
+ dev_err(&adap->dev,
+ "Failed to add properties to client %s: %d\n",
+ client->name, status);
+ goto out_err;
+ }
+ }
+
+ status = device_register(&client->dev);
+ if (status)
+ goto out_free_props;
+
+ dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
+ client->name, dev_name(&client->dev));
+
+ return client;
+
+out_free_props:
+ if (info->properties)
+ device_remove_properties(&client->dev);
+out_err:
+ dev_err(&adap->dev,
+ "Failed to register i2c client %s at 0x%02x (%d)\n",
+ client->name, client->addr, status);
+out_err_silent:
+ kfree(client);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(i2c_new_device);
+
+
+/**
+ * i2c_unregister_device - reverse effect of i2c_new_device()
+ * @client: value returned from i2c_new_device()
+ * Context: can sleep
+ */
+void i2c_unregister_device(struct i2c_client *client)
+{
+ if (client->dev.of_node)
+ of_node_clear_flag(client->dev.of_node, OF_POPULATED);
+ if (ACPI_COMPANION(&client->dev))
+ acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));
+ device_unregister(&client->dev);
+}
+EXPORT_SYMBOL_GPL(i2c_unregister_device);
+
+
+static const struct i2c_device_id dummy_id[] = {
+ { "dummy", 0 },
+ { },
+};
+
+static int dummy_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ return 0;
+}
+
+static int dummy_remove(struct i2c_client *client)
+{
+ return 0;
+}
+
+static struct i2c_driver dummy_driver = {
+ .driver.name = "dummy",
+ .probe = dummy_probe,
+ .remove = dummy_remove,
+ .id_table = dummy_id,
+};
+
+/**
+ * i2c_new_dummy - return a new i2c device bound to a dummy driver
+ * @adapter: the adapter managing the device
+ * @address: seven bit address to be used
+ * Context: can sleep
+ *
+ * This returns an I2C client bound to the "dummy" driver, intended for use
+ * with devices that consume multiple addresses. Examples of such chips
+ * include various EEPROMS (like 24c04 and 24c08 models).
+ *
+ * These dummy devices have two main uses. First, most I2C and SMBus calls
+ * except i2c_transfer() need a client handle; the dummy will be that handle.
+ * And second, this prevents the specified address from being bound to a
+ * different driver.
+ *
+ * This returns the new i2c client, which should be saved for later use with
+ * i2c_unregister_device(); or NULL to indicate an error.
+ */
+struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
+{
+ struct i2c_board_info info = {
+ I2C_BOARD_INFO("dummy", address),
+ };
+
+ return i2c_new_device(adapter, &info);
+}
+EXPORT_SYMBOL_GPL(i2c_new_dummy);
+
+/**
+ * i2c_new_secondary_device - Helper to get the instantiated secondary address
+ * and create the associated device
+ * @client: Handle to the primary client
+ * @name: Handle to specify which secondary address to get
+ * @default_addr: Used as a fallback if no secondary address was specified
+ * Context: can sleep
+ *
+ * I2C clients can be composed of multiple I2C slaves bound together in a single
+ * component. The I2C client driver then binds to the master I2C slave and needs
+ * to create I2C dummy clients to communicate with all the other slaves.
+ *
+ * This function creates and returns an I2C dummy client whose I2C address is
+ * retrieved from the platform firmware based on the given slave name. If no
+ * address is specified by the firmware default_addr is used.
+ *
+ * On DT-based platforms the address is retrieved from the "reg" property entry
+ * cell whose "reg-names" value matches the slave name.
+ *
+ * This returns the new i2c client, which should be saved for later use with
+ * i2c_unregister_device(); or NULL to indicate an error.
+ */
+struct i2c_client *i2c_new_secondary_device(struct i2c_client *client,
+ const char *name,
+ u16 default_addr)
+{
+ struct device_node *np = client->dev.of_node;
+ u32 addr = default_addr;
+ int i;
+
+ if (np) {
+ i = of_property_match_string(np, "reg-names", name);
+ if (i >= 0)
+ of_property_read_u32_index(np, "reg", i, &addr);
+ }
+
+ dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
+ return i2c_new_dummy(client->adapter, addr);
+}
+EXPORT_SYMBOL_GPL(i2c_new_secondary_device);
+
+/* ------------------------------------------------------------------------- */
+
+/* I2C bus adapters -- one roots each I2C or SMBUS segment */
+
+static void i2c_adapter_dev_release(struct device *dev)
+{
+ struct i2c_adapter *adap = to_i2c_adapter(dev);
+ complete(&adap->dev_released);
+}
+
+unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
+{
+ unsigned int depth = 0;
+
+ while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
+ depth++;
+
+ WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES,
+ "adapter depth exceeds lockdep subclass limit\n");
+
+ return depth;
+}
+EXPORT_SYMBOL_GPL(i2c_adapter_depth);
+
+/*
+ * Let users instantiate I2C devices through sysfs. This can be used when
+ * platform initialization code doesn't contain the proper data for
+ * whatever reason. Also useful for drivers that do device detection and
+ * detection fails, either because the device uses an unexpected address,
+ * or this is a compatible device with different ID register values.
+ *
+ * Parameter checking may look overzealous, but we really don't want
+ * the user to provide incorrect parameters.
+ */
+static ssize_t
+i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct i2c_adapter *adap = to_i2c_adapter(dev);
+ struct i2c_board_info info;
+ struct i2c_client *client;
+ char *blank, end;
+ int res;
+
+ memset(&info, 0, sizeof(struct i2c_board_info));
+
+ blank = strchr(buf, ' ');
+ if (!blank) {
+ dev_err(dev, "%s: Missing parameters\n", "new_device");
+ return -EINVAL;
+ }
+ if (blank - buf > I2C_NAME_SIZE - 1) {
+ dev_err(dev, "%s: Invalid device name\n", "new_device");
+ return -EINVAL;
+ }
+ memcpy(info.type, buf, blank - buf);
+
+ /* Parse remaining parameters, reject extra parameters */
+ res = sscanf(++blank, "%hi%c", &info.addr, &end);
+ if (res < 1) {
+ dev_err(dev, "%s: Can't parse I2C address\n", "new_device");
+ return -EINVAL;
+ }
+ if (res > 1 && end != '\n') {
+ dev_err(dev, "%s: Extra parameters\n", "new_device");
+ return -EINVAL;
+ }
+
+ if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) {
+ info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT;
+ info.flags |= I2C_CLIENT_TEN;
+ }
+
+ if (info.addr & I2C_ADDR_OFFSET_SLAVE) {
+ info.addr &= ~I2C_ADDR_OFFSET_SLAVE;
+ info.flags |= I2C_CLIENT_SLAVE;
+ }
+
+ client = i2c_new_device(adap, &info);
+ if (!client)
+ return -EINVAL;
+
+ /* Keep track of the added device */
+ mutex_lock(&adap->userspace_clients_lock);
+ list_add_tail(&client->detected, &adap->userspace_clients);
+ mutex_unlock(&adap->userspace_clients_lock);
+ dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
+ info.type, info.addr);
+
+ return count;
+}
+static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device);
+
+/*
+ * And of course let the users delete the devices they instantiated, if
+ * they got it wrong. This interface can only be used to delete devices
+ * instantiated by i2c_sysfs_new_device above. This guarantees that we
+ * don't delete devices to which some kernel code still has references.
+ *
+ * Parameter checking may look overzealous, but we really don't want
+ * the user to delete the wrong device.
+ */
+static ssize_t
+i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct i2c_adapter *adap = to_i2c_adapter(dev);
+ struct i2c_client *client, *next;
+ unsigned short addr;
+ char end;
+ int res;
+
+ /* Parse parameters, reject extra parameters */
+ res = sscanf(buf, "%hi%c", &addr, &end);
+ if (res < 1) {
+ dev_err(dev, "%s: Can't parse I2C address\n", "delete_device");
+ return -EINVAL;
+ }
+ if (res > 1 && end != '\n') {
+ dev_err(dev, "%s: Extra parameters\n", "delete_device");
+ return -EINVAL;
+ }
+
+ /* Make sure the device was added through sysfs */
+ res = -ENOENT;
+ mutex_lock_nested(&adap->userspace_clients_lock,
+ i2c_adapter_depth(adap));
+ list_for_each_entry_safe(client, next, &adap->userspace_clients,
+ detected) {
+ if (i2c_encode_flags_to_addr(client) == addr) {
+ dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
+ "delete_device", client->name, client->addr);
+
+ list_del(&client->detected);
+ i2c_unregister_device(client);
+ res = count;
+ break;
+ }
+ }
+ mutex_unlock(&adap->userspace_clients_lock);
+
+ if (res < 0)
+ dev_err(dev, "%s: Can't find device in list\n",
+ "delete_device");
+ return res;
+}
+static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL,
+ i2c_sysfs_delete_device);
+
+static struct attribute *i2c_adapter_attrs[] = {
+ &dev_attr_name.attr,
+ &dev_attr_new_device.attr,
+ &dev_attr_delete_device.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(i2c_adapter);
+
+struct device_type i2c_adapter_type = {
+ .groups = i2c_adapter_groups,
+ .release = i2c_adapter_dev_release,
+};
+EXPORT_SYMBOL_GPL(i2c_adapter_type);
+
+/**
+ * i2c_verify_adapter - return parameter as i2c_adapter or NULL
+ * @dev: device, probably from some driver model iterator
+ *
+ * When traversing the driver model tree, perhaps using driver model
+ * iterators like @device_for_each_child(), you can't assume very much
+ * about the nodes you find. Use this function to avoid oopses caused
+ * by wrongly treating some non-I2C device as an i2c_adapter.
+ */
+struct i2c_adapter *i2c_verify_adapter(struct device *dev)
+{
+ return (dev->type == &i2c_adapter_type)
+ ? to_i2c_adapter(dev)
+ : NULL;
+}
+EXPORT_SYMBOL(i2c_verify_adapter);
+
+#ifdef CONFIG_I2C_COMPAT
+static struct class_compat *i2c_adapter_compat_class;
+#endif
+
+static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
+{
+ struct i2c_devinfo *devinfo;
+
+ down_read(&__i2c_board_lock);
+ list_for_each_entry(devinfo, &__i2c_board_list, list) {
+ if (devinfo->busnum == adapter->nr
+ && !i2c_new_device(adapter,
+ &devinfo->board_info))
+ dev_err(&adapter->dev,
+ "Can't create device at 0x%02x\n",
+ devinfo->board_info.addr);
+ }
+ up_read(&__i2c_board_lock);
+}
+
+/* OF support code */
+
+#if IS_ENABLED(CONFIG_OF)
+static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
+ struct device_node *node)
+{
+ struct i2c_client *result;
+ struct i2c_board_info info = {};
+ struct dev_archdata dev_ad = {};
+ const __be32 *addr_be;
+ u32 addr;
+ int len;
+
+ dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name);
+
+ if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) {
+ dev_err(&adap->dev, "of_i2c: modalias failure on %s\n",
+ node->full_name);
+ return ERR_PTR(-EINVAL);
+ }
+
+ addr_be = of_get_property(node, "reg", &len);
+ if (!addr_be || (len < sizeof(*addr_be))) {
+ dev_err(&adap->dev, "of_i2c: invalid reg on %s\n",
+ node->full_name);
+ return ERR_PTR(-EINVAL);
+ }
+
+ addr = be32_to_cpup(addr_be);
+ if (addr & I2C_TEN_BIT_ADDRESS) {
+ addr &= ~I2C_TEN_BIT_ADDRESS;
+ info.flags |= I2C_CLIENT_TEN;
+ }
+
+ if (addr & I2C_OWN_SLAVE_ADDRESS) {
+ addr &= ~I2C_OWN_SLAVE_ADDRESS;
+ info.flags |= I2C_CLIENT_SLAVE;
+ }
+
+ if (i2c_check_addr_validity(addr, info.flags)) {
+ dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n",
+ addr, node->full_name);
+ return ERR_PTR(-EINVAL);
+ }
+
+ info.addr = addr;
+ info.of_node = of_node_get(node);
+ info.archdata = &dev_ad;
+
+ if (of_property_read_bool(node, "host-notify"))
+ info.flags |= I2C_CLIENT_HOST_NOTIFY;
+
+ if (of_get_property(node, "wakeup-source", NULL))
+ info.flags |= I2C_CLIENT_WAKE;
+
+ result = i2c_new_device(adap, &info);
+ if (result == NULL) {
+ dev_err(&adap->dev, "of_i2c: Failure registering %s\n",
+ node->full_name);
+ of_node_put(node);
+ return ERR_PTR(-EINVAL);
+ }
+ return result;
+}
+
+static void of_i2c_register_devices(struct i2c_adapter *adap)
+{
+ struct device_node *bus, *node;
+ struct i2c_client *client;
+
+ /* Only register child devices if the adapter has a node pointer set */
+ if (!adap->dev.of_node)
+ return;
+
+ dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");
+
+ bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus");
+ if (!bus)
+ bus = of_node_get(adap->dev.of_node);
+
+ for_each_available_child_of_node(bus, node) {
+ if (of_node_test_and_set_flag(node, OF_POPULATED))
+ continue;
+
+ client = of_i2c_register_device(adap, node);
+ if (IS_ERR(client)) {
+ dev_warn(&adap->dev,
+ "Failed to create I2C device for %s\n",
+ node->full_name);
+ of_node_clear_flag(node, OF_POPULATED);
+ }
+ }
+
+ of_node_put(bus);
+}
+
+static int of_dev_node_match(struct device *dev, void *data)
+{
+ return dev->of_node == data;
+}
+
+/* must call put_device() when done with returned i2c_client device */
+struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
+{
+ struct device *dev;
+ struct i2c_client *client;
+
+ dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match);
+ if (!dev)
+ return NULL;
+
+ client = i2c_verify_client(dev);
+ if (!client)
+ put_device(dev);
+
+ return client;
+}
+EXPORT_SYMBOL(of_find_i2c_device_by_node);
+
+/* must call put_device() when done with returned i2c_adapter device */
+struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
+{
+ struct device *dev;
+ struct i2c_adapter *adapter;
+
+ dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match);
+ if (!dev)
+ return NULL;
+
+ adapter = i2c_verify_adapter(dev);
+ if (!adapter)
+ put_device(dev);
+
+ return adapter;
+}
+EXPORT_SYMBOL(of_find_i2c_adapter_by_node);
+
+/* must call i2c_put_adapter() when done with returned i2c_adapter device */
+struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
+{
+ struct i2c_adapter *adapter;
+
+ adapter = of_find_i2c_adapter_by_node(node);
+ if (!adapter)
+ return NULL;
+
+ if (!try_module_get(adapter->owner)) {
+ put_device(&adapter->dev);
+ adapter = NULL;
+ }
+
+ return adapter;
+}
+EXPORT_SYMBOL(of_get_i2c_adapter_by_node);
+
+static const struct of_device_id*
+i2c_of_match_device_sysfs(const struct of_device_id *matches,
+ struct i2c_client *client)
+{
+ const char *name;
+
+ for (; matches->compatible[0]; matches++) {
+ /*
+ * Adding devices through the i2c sysfs interface provides us
+ * a string to match which may be compatible with the device
+ * tree compatible strings, however with no actual of_node the
+ * of_match_device() will not match
+ */
+ if (sysfs_streq(client->name, matches->compatible))
+ return matches;
+
+ name = strchr(matches->compatible, ',');
+ if (!name)
+ name = matches->compatible;
+ else
+ name++;
+
+ if (sysfs_streq(client->name, name))
+ return matches;
+ }
+
+ return NULL;
+}
+
+const struct of_device_id
+*i2c_of_match_device(const struct of_device_id *matches,
+ struct i2c_client *client)
+{
+ const struct of_device_id *match;
+
+ if (!(client && matches))
+ return NULL;
+
+ match = of_match_device(matches, &client->dev);
+ if (match)
+ return match;
+
+ return i2c_of_match_device_sysfs(matches, client);
+}
+EXPORT_SYMBOL_GPL(i2c_of_match_device);
+#else
+static void of_i2c_register_devices(struct i2c_adapter *adap) { }
+#endif /* CONFIG_OF */
+
+static int i2c_do_add_adapter(struct i2c_driver *driver,
+ struct i2c_adapter *adap)
+{
+ /* Detect supported devices on that bus, and instantiate them */
+ i2c_detect(adap, driver);
+
+ /* Let legacy drivers scan this bus for matching devices */
+ if (driver->attach_adapter) {
+ dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n",
+ driver->driver.name);
+ dev_warn(&adap->dev,
+ "Please use another way to instantiate your i2c_client\n");
+ /* We ignore the return code; if it fails, too bad */
+ driver->attach_adapter(adap);
+ }
+ return 0;
+}
+
+static int __process_new_adapter(struct device_driver *d, void *data)
+{
+ return i2c_do_add_adapter(to_i2c_driver(d), data);
+}
+
+static const struct i2c_lock_operations i2c_adapter_lock_ops = {
+ .lock_bus = i2c_adapter_lock_bus,
+ .trylock_bus = i2c_adapter_trylock_bus,
+ .unlock_bus = i2c_adapter_unlock_bus,
+};
+
+static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap)
+{
+ struct irq_domain *domain = adap->host_notify_domain;
+ irq_hw_number_t hwirq;
+
+ if (!domain)
+ return;
+
+ for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++)
+ irq_dispose_mapping(irq_find_mapping(domain, hwirq));
+
+ irq_domain_remove(domain);
+ adap->host_notify_domain = NULL;
+}
+
+static int i2c_host_notify_irq_map(struct irq_domain *h,
+ unsigned int virq,
+ irq_hw_number_t hw_irq_num)
+{
+ irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
+
+ return 0;
+}
+
+static const struct irq_domain_ops i2c_host_notify_irq_ops = {
+ .map = i2c_host_notify_irq_map,
+};
+
+static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap)
+{
+ struct irq_domain *domain;
+
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY))
+ return 0;
+
+ domain = irq_domain_create_linear(adap->dev.fwnode,
+ I2C_ADDR_7BITS_COUNT,
+ &i2c_host_notify_irq_ops, adap);
+ if (!domain)
+ return -ENOMEM;
+
+ adap->host_notify_domain = domain;
+
+ return 0;
+}
+
+/**
+ * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct
+ * I2C client.
+ * @adap: the adapter
+ * @addr: the I2C address of the notifying device
+ * Context: can't sleep
+ *
+ * Helper function to be called from an I2C bus driver's interrupt
+ * handler. It will schedule the Host Notify IRQ.
+ */
+int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)
+{
+ int irq;
+
+ if (!adap)
+ return -EINVAL;
+
+ irq = irq_find_mapping(adap->host_notify_domain, addr);
+ if (irq <= 0)
+ return -ENXIO;
+
+ generic_handle_irq(irq);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify);
+
+static int i2c_register_adapter(struct i2c_adapter *adap)
+{
+ int res = -EINVAL;
+
+ /* Can't register until after driver model init */
+ if (WARN_ON(!is_registered)) {
+ res = -EAGAIN;
+ goto out_list;
+ }
+
+ /* Sanity checks */
+ if (WARN(!adap->name[0], "i2c adapter has no name"))
+ goto out_list;
+
+ if (!adap->algo) {
+ pr_err("adapter '%s': no algo supplied!\n", adap->name);
+ goto out_list;
+ }
+
+ if (!adap->lock_ops)
+ adap->lock_ops = &i2c_adapter_lock_ops;
+
+ rt_mutex_init(&adap->bus_lock);
+ rt_mutex_init(&adap->mux_lock);
+ mutex_init(&adap->userspace_clients_lock);
+ INIT_LIST_HEAD(&adap->userspace_clients);
+
+ /* Set default timeout to 1 second if not already set */
+ if (adap->timeout == 0)
+ adap->timeout = HZ;
+
+ /* register soft irqs for Host Notify */
+ res = i2c_setup_host_notify_irq_domain(adap);
+ if (res) {
+ pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n",
+ adap->name, res);
+ goto out_list;
+ }
+
+ dev_set_name(&adap->dev, "i2c-%d", adap->nr);
+ adap->dev.bus = &i2c_bus_type;
+ adap->dev.type = &i2c_adapter_type;
+ res = device_register(&adap->dev);
+ if (res) {
+ pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
+ goto out_list;
+ }
+
+ dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
+
+ pm_runtime_no_callbacks(&adap->dev);
+ pm_suspend_ignore_children(&adap->dev, true);
+ pm_runtime_enable(&adap->dev);
+
+#ifdef CONFIG_I2C_COMPAT
+ res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev,
+ adap->dev.parent);
+ if (res)
+ dev_warn(&adap->dev,
+ "Failed to create compatibility class link\n");
+#endif
+
+ i2c_init_recovery(adap);
+
+ /* create pre-declared device nodes */
+ of_i2c_register_devices(adap);
+ i2c_acpi_register_devices(adap);
+ i2c_acpi_install_space_handler(adap);
+
+ if (adap->nr < __i2c_first_dynamic_bus_num)
+ i2c_scan_static_board_info(adap);
+
+ /* Notify drivers */
+ mutex_lock(&core_lock);
+ bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter);
+ mutex_unlock(&core_lock);
+
+ return 0;
+
+out_list:
+ mutex_lock(&core_lock);
+ idr_remove(&i2c_adapter_idr, adap->nr);
+ mutex_unlock(&core_lock);
+ return res;
+}
+
+/**
+ * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1
+ * @adap: the adapter to register (with adap->nr initialized)
+ * Context: can sleep
+ *
+ * See i2c_add_numbered_adapter() for details.
+ */
+static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
+{
+ int id;
+
+ mutex_lock(&core_lock);
+ id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL);
+ mutex_unlock(&core_lock);
+ if (WARN(id < 0, "couldn't get idr"))
+ return id == -ENOSPC ? -EBUSY : id;
+
+ return i2c_register_adapter(adap);
+}
+
+/**
+ * i2c_add_adapter - declare i2c adapter, use dynamic bus number
+ * @adapter: the adapter to add
+ * Context: can sleep
+ *
+ * This routine is used to declare an I2C adapter when its bus number
+ * doesn't matter or when its bus number is specified by an dt alias.
+ * Examples of bases when the bus number doesn't matter: I2C adapters
+ * dynamically added by USB links or PCI plugin cards.
+ *
+ * When this returns zero, a new bus number was allocated and stored
+ * in adap->nr, and the specified adapter became available for clients.
+ * Otherwise, a negative errno value is returned.
+ */
+int i2c_add_adapter(struct i2c_adapter *adapter)
+{
+ struct device *dev = &adapter->dev;
+ int id;
+
+ if (dev->of_node) {
+ id = of_alias_get_id(dev->of_node, "i2c");
+ if (id >= 0) {
+ adapter->nr = id;
+ return __i2c_add_numbered_adapter(adapter);
+ }
+ }
+
+ mutex_lock(&core_lock);
+ id = idr_alloc(&i2c_adapter_idr, adapter,
+ __i2c_first_dynamic_bus_num, 0, GFP_KERNEL);
+ mutex_unlock(&core_lock);
+ if (WARN(id < 0, "couldn't get idr"))
+ return id;
+
+ adapter->nr = id;
+
+ return i2c_register_adapter(adapter);
+}
+EXPORT_SYMBOL(i2c_add_adapter);
+
+/**
+ * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
+ * @adap: the adapter to register (with adap->nr initialized)
+ * Context: can sleep
+ *
+ * This routine is used to declare an I2C adapter when its bus number
+ * matters. For example, use it for I2C adapters from system-on-chip CPUs,
+ * or otherwise built in to the system's mainboard, and where i2c_board_info
+ * is used to properly configure I2C devices.
+ *
+ * If the requested bus number is set to -1, then this function will behave
+ * identically to i2c_add_adapter, and will dynamically assign a bus number.
+ *
+ * If no devices have pre-been declared for this bus, then be sure to
+ * register the adapter before any dynamically allocated ones. Otherwise
+ * the required bus ID may not be available.
+ *
+ * When this returns zero, the specified adapter became available for
+ * clients using the bus number provided in adap->nr. Also, the table
+ * of I2C devices pre-declared using i2c_register_board_info() is scanned,
+ * and the appropriate driver model device nodes are created. Otherwise, a
+ * negative errno value is returned.
+ */
+int i2c_add_numbered_adapter(struct i2c_adapter *adap)
+{
+ if (adap->nr == -1) /* -1 means dynamically assign bus id */
+ return i2c_add_adapter(adap);
+
+ return __i2c_add_numbered_adapter(adap);
+}
+EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
+
+static void i2c_do_del_adapter(struct i2c_driver *driver,
+ struct i2c_adapter *adapter)
+{
+ struct i2c_client *client, *_n;
+
+ /* Remove the devices we created ourselves as the result of hardware
+ * probing (using a driver's detect method) */
+ list_for_each_entry_safe(client, _n, &driver->clients, detected) {
+ if (client->adapter == adapter) {
+ dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
+ client->name, client->addr);
+ list_del(&client->detected);
+ i2c_unregister_device(client);
+ }
+ }
+}
+
+static int __unregister_client(struct device *dev, void *dummy)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ if (client && strcmp(client->name, "dummy"))
+ i2c_unregister_device(client);
+ return 0;
+}
+
+static int __unregister_dummy(struct device *dev, void *dummy)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ if (client)
+ i2c_unregister_device(client);
+ return 0;
+}
+
+static int __process_removed_adapter(struct device_driver *d, void *data)
+{
+ i2c_do_del_adapter(to_i2c_driver(d), data);
+ return 0;
+}
+
+/**
+ * i2c_del_adapter - unregister I2C adapter
+ * @adap: the adapter being unregistered
+ * Context: can sleep
+ *
+ * This unregisters an I2C adapter which was previously registered
+ * by @i2c_add_adapter or @i2c_add_numbered_adapter.
+ */
+void i2c_del_adapter(struct i2c_adapter *adap)
+{
+ struct i2c_adapter *found;
+ struct i2c_client *client, *next;
+
+ /* First make sure that this adapter was ever added */
+ mutex_lock(&core_lock);
+ found = idr_find(&i2c_adapter_idr, adap->nr);
+ mutex_unlock(&core_lock);
+ if (found != adap) {
+ pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);
+ return;
+ }
+
+ i2c_acpi_remove_space_handler(adap);
+ /* Tell drivers about this removal */
+ mutex_lock(&core_lock);
+ bus_for_each_drv(&i2c_bus_type, NULL, adap,
+ __process_removed_adapter);
+ mutex_unlock(&core_lock);
+
+ /* Remove devices instantiated from sysfs */
+ mutex_lock_nested(&adap->userspace_clients_lock,
+ i2c_adapter_depth(adap));
+ list_for_each_entry_safe(client, next, &adap->userspace_clients,
+ detected) {
+ dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
+ client->addr);
+ list_del(&client->detected);
+ i2c_unregister_device(client);
+ }
+ mutex_unlock(&adap->userspace_clients_lock);
+
+ /* Detach any active clients. This can't fail, thus we do not
+ * check the returned value. This is a two-pass process, because
+ * we can't remove the dummy devices during the first pass: they
+ * could have been instantiated by real devices wishing to clean
+ * them up properly, so we give them a chance to do that first. */
+ device_for_each_child(&adap->dev, NULL, __unregister_client);
+ device_for_each_child(&adap->dev, NULL, __unregister_dummy);
+
+#ifdef CONFIG_I2C_COMPAT
+ class_compat_remove_link(i2c_adapter_compat_class, &adap->dev,
+ adap->dev.parent);
+#endif
+
+ /* device name is gone after device_unregister */
+ dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
+
+ pm_runtime_disable(&adap->dev);
+
+ i2c_host_notify_irq_teardown(adap);
+
+ /* wait until all references to the device are gone
+ *
+ * FIXME: This is old code and should ideally be replaced by an
+ * alternative which results in decoupling the lifetime of the struct
+ * device from the i2c_adapter, like spi or netdev do. Any solution
+ * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled!
+ */
+ init_completion(&adap->dev_released);
+ device_unregister(&adap->dev);
+ wait_for_completion(&adap->dev_released);
+
+ /* free bus id */
+ mutex_lock(&core_lock);
+ idr_remove(&i2c_adapter_idr, adap->nr);
+ mutex_unlock(&core_lock);
+
+ /* Clear the device structure in case this adapter is ever going to be
+ added again */
+ memset(&adap->dev, 0, sizeof(adap->dev));
+}
+EXPORT_SYMBOL(i2c_del_adapter);
+
+/**
+ * i2c_parse_fw_timings - get I2C related timing parameters from firmware
+ * @dev: The device to scan for I2C timing properties
+ * @t: the i2c_timings struct to be filled with values
+ * @use_defaults: bool to use sane defaults derived from the I2C specification
+ * when properties are not found, otherwise use 0
+ *
+ * Scan the device for the generic I2C properties describing timing parameters
+ * for the signal and fill the given struct with the results. If a property was
+ * not found and use_defaults was true, then maximum timings are assumed which
+ * are derived from the I2C specification. If use_defaults is not used, the
+ * results will be 0, so drivers can apply their own defaults later. The latter
+ * is mainly intended for avoiding regressions of existing drivers which want
+ * to switch to this function. New drivers almost always should use the defaults.
+ */
+
+void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults)
+{
+ int ret;
+
+ memset(t, 0, sizeof(*t));
+
+ ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz);
+ if (ret && use_defaults)
+ t->bus_freq_hz = 100000;
+
+ ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns);
+ if (ret && use_defaults) {
+ if (t->bus_freq_hz <= 100000)
+ t->scl_rise_ns = 1000;
+ else if (t->bus_freq_hz <= 400000)
+ t->scl_rise_ns = 300;
+ else
+ t->scl_rise_ns = 120;
+ }
+
+ ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns);
+ if (ret && use_defaults) {
+ if (t->bus_freq_hz <= 400000)
+ t->scl_fall_ns = 300;
+ else
+ t->scl_fall_ns = 120;
+ }
+
+ device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns);
+
+ ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns);
+ if (ret && use_defaults)
+ t->sda_fall_ns = t->scl_fall_ns;
+}
+EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);
+
+/* ------------------------------------------------------------------------- */
+
+int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *))
+{
+ int res;
+
+ mutex_lock(&core_lock);
+ res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn);
+ mutex_unlock(&core_lock);
+
+ return res;
+}
+EXPORT_SYMBOL_GPL(i2c_for_each_dev);
+
+static int __process_new_driver(struct device *dev, void *data)
+{
+ if (dev->type != &i2c_adapter_type)
+ return 0;
+ return i2c_do_add_adapter(data, to_i2c_adapter(dev));
+}
+
+/*
+ * An i2c_driver is used with one or more i2c_client (device) nodes to access
+ * i2c slave chips, on a bus instance associated with some i2c_adapter.
+ */
+
+int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
+{
+ int res;
+
+ /* Can't register until after driver model init */
+ if (WARN_ON(!is_registered))
+ return -EAGAIN;
+
+ /* add the driver to the list of i2c drivers in the driver core */
+ driver->driver.owner = owner;
+ driver->driver.bus = &i2c_bus_type;
+ INIT_LIST_HEAD(&driver->clients);
+
+ /* When registration returns, the driver core
+ * will have called probe() for all matching-but-unbound devices.
+ */
+ res = driver_register(&driver->driver);
+ if (res)
+ return res;
+
+ pr_debug("driver [%s] registered\n", driver->driver.name);
+
+ /* Walk the adapters that are already present */
+ i2c_for_each_dev(driver, __process_new_driver);
+
+ return 0;
+}
+EXPORT_SYMBOL(i2c_register_driver);
+
+static int __process_removed_driver(struct device *dev, void *data)
+{
+ if (dev->type == &i2c_adapter_type)
+ i2c_do_del_adapter(data, to_i2c_adapter(dev));
+ return 0;
+}
+
+/**
+ * i2c_del_driver - unregister I2C driver
+ * @driver: the driver being unregistered
+ * Context: can sleep
+ */
+void i2c_del_driver(struct i2c_driver *driver)
+{
+ i2c_for_each_dev(driver, __process_removed_driver);
+
+ driver_unregister(&driver->driver);
+ pr_debug("driver [%s] unregistered\n", driver->driver.name);
+}
+EXPORT_SYMBOL(i2c_del_driver);
+
+/* ------------------------------------------------------------------------- */
+
+/**
+ * i2c_use_client - increments the reference count of the i2c client structure
+ * @client: the client being referenced
+ *
+ * Each live reference to a client should be refcounted. The driver model does
+ * that automatically as part of driver binding, so that most drivers don't
+ * need to do this explicitly: they hold a reference until they're unbound
+ * from the device.
+ *
+ * A pointer to the client with the incremented reference counter is returned.
+ */
+struct i2c_client *i2c_use_client(struct i2c_client *client)
+{
+ if (client && get_device(&client->dev))
+ return client;
+ return NULL;
+}
+EXPORT_SYMBOL(i2c_use_client);
+
+/**
+ * i2c_release_client - release a use of the i2c client structure
+ * @client: the client being no longer referenced
+ *
+ * Must be called when a user of a client is finished with it.
+ */
+void i2c_release_client(struct i2c_client *client)
+{
+ if (client)
+ put_device(&client->dev);
+}
+EXPORT_SYMBOL(i2c_release_client);
+
+struct i2c_cmd_arg {
+ unsigned cmd;
+ void *arg;
+};
+
+static int i2c_cmd(struct device *dev, void *_arg)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+ struct i2c_cmd_arg *arg = _arg;
+ struct i2c_driver *driver;
+
+ if (!client || !client->dev.driver)
+ return 0;
+
+ driver = to_i2c_driver(client->dev.driver);
+ if (driver->command)
+ driver->command(client, arg->cmd, arg->arg);
+ return 0;
+}
+
+void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
+{
+ struct i2c_cmd_arg cmd_arg;
+
+ cmd_arg.cmd = cmd;
+ cmd_arg.arg = arg;
+ device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
+}
+EXPORT_SYMBOL(i2c_clients_command);
+
+#if IS_ENABLED(CONFIG_OF_DYNAMIC)
+static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
+ void *arg)
+{
+ struct of_reconfig_data *rd = arg;
+ struct i2c_adapter *adap;
+ struct i2c_client *client;
+
+ switch (of_reconfig_get_state_change(action, rd)) {
+ case OF_RECONFIG_CHANGE_ADD:
+ adap = of_find_i2c_adapter_by_node(rd->dn->parent);
+ if (adap == NULL)
+ return NOTIFY_OK; /* not for us */
+
+ if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
+ put_device(&adap->dev);
+ return NOTIFY_OK;
+ }
+
+ client = of_i2c_register_device(adap, rd->dn);
+ put_device(&adap->dev);
+
+ if (IS_ERR(client)) {
+ dev_err(&adap->dev, "failed to create client for '%s'\n",
+ rd->dn->full_name);
+ of_node_clear_flag(rd->dn, OF_POPULATED);
+ return notifier_from_errno(PTR_ERR(client));
+ }
+ break;
+ case OF_RECONFIG_CHANGE_REMOVE:
+ /* already depopulated? */
+ if (!of_node_check_flag(rd->dn, OF_POPULATED))
+ return NOTIFY_OK;
+
+ /* find our device by node */
+ client = of_find_i2c_device_by_node(rd->dn);
+ if (client == NULL)
+ return NOTIFY_OK; /* no? not meant for us */
+
+ /* unregister takes one ref away */
+ i2c_unregister_device(client);
+
+ /* and put the reference of the find */
+ put_device(&client->dev);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+static struct notifier_block i2c_of_notifier = {
+ .notifier_call = of_i2c_notify,
+};
+#else
+extern struct notifier_block i2c_of_notifier;
+#endif /* CONFIG_OF_DYNAMIC */
+
+static int __init i2c_init(void)
+{
+ int retval;
+
+ retval = of_alias_get_highest_id("i2c");
+
+ down_write(&__i2c_board_lock);
+ if (retval >= __i2c_first_dynamic_bus_num)
+ __i2c_first_dynamic_bus_num = retval + 1;
+ up_write(&__i2c_board_lock);
+
+ retval = bus_register(&i2c_bus_type);
+ if (retval)
+ return retval;
+
+ is_registered = true;
+
+#ifdef CONFIG_I2C_COMPAT
+ i2c_adapter_compat_class = class_compat_register("i2c-adapter");
+ if (!i2c_adapter_compat_class) {
+ retval = -ENOMEM;
+ goto bus_err;
+ }
+#endif
+ retval = i2c_add_driver(&dummy_driver);
+ if (retval)
+ goto class_err;
+
+ if (IS_ENABLED(CONFIG_OF_DYNAMIC))
+ WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier));
+ if (IS_ENABLED(CONFIG_ACPI))
+ WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier));
+
+ return 0;
+
+class_err:
+#ifdef CONFIG_I2C_COMPAT
+ class_compat_unregister(i2c_adapter_compat_class);
+bus_err:
+#endif
+ is_registered = false;
+ bus_unregister(&i2c_bus_type);
+ return retval;
+}
+
+static void __exit i2c_exit(void)
+{
+ if (IS_ENABLED(CONFIG_ACPI))
+ WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier));
+ if (IS_ENABLED(CONFIG_OF_DYNAMIC))
+ WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier));
+ i2c_del_driver(&dummy_driver);
+#ifdef CONFIG_I2C_COMPAT
+ class_compat_unregister(i2c_adapter_compat_class);
+#endif
+ bus_unregister(&i2c_bus_type);
+ tracepoint_synchronize_unregister();
+}
+
+/* We must initialize early, because some subsystems register i2c drivers
+ * in subsys_initcall() code, but are linked (and initialized) before i2c.
+ */
+postcore_initcall(i2c_init);
+module_exit(i2c_exit);
+
+/* ----------------------------------------------------
+ * the functional interface to the i2c busses.
+ * ----------------------------------------------------
+ */
+
+/* Check if val is exceeding the quirk IFF quirk is non 0 */
+#define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk)))
+
+static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg)
+{
+ dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n",
+ err_msg, msg->addr, msg->len,
+ msg->flags & I2C_M_RD ? "read" : "write");
+ return -EOPNOTSUPP;
+}
+
+static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ const struct i2c_adapter_quirks *q = adap->quirks;
+ int max_num = q->max_num_msgs, i;
+ bool do_len_check = true;
+
+ if (q->flags & I2C_AQ_COMB) {
+ max_num = 2;
+
+ /* special checks for combined messages */
+ if (num == 2) {
+ if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD)
+ return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write");
+
+ if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD))
+ return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read");
+
+ if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr)
+ return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr");
+
+ if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len))
+ return i2c_quirk_error(adap, &msgs[0], "msg too long");
+
+ if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len))
+ return i2c_quirk_error(adap, &msgs[1], "msg too long");
+
+ do_len_check = false;
+ }
+ }
+
+ if (i2c_quirk_exceeded(num, max_num))
+ return i2c_quirk_error(adap, &msgs[0], "too many messages");
+
+ for (i = 0; i < num; i++) {
+ u16 len = msgs[i].len;
+
+ if (msgs[i].flags & I2C_M_RD) {
+ if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len))
+ return i2c_quirk_error(adap, &msgs[i], "msg too long");
+ } else {
+ if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len))
+ return i2c_quirk_error(adap, &msgs[i], "msg too long");
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * __i2c_transfer - unlocked flavor of i2c_transfer
+ * @adap: Handle to I2C bus
+ * @msgs: One or more messages to execute before STOP is issued to
+ * terminate the operation; each message begins with a START.
+ * @num: Number of messages to be executed.
+ *
+ * Returns negative errno, else the number of messages executed.
+ *
+ * Adapter lock must be held when calling this function. No debug logging
+ * takes place. adap->algo->master_xfer existence isn't checked.
+ */
+int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ unsigned long orig_jiffies;
+ int ret, try;
+
+ if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
+ return -EOPNOTSUPP;
+
+ /* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets
+ * enabled. This is an efficient way of keeping the for-loop from
+ * being executed when not needed.
+ */
+ if (static_key_false(&i2c_trace_msg)) {
+ int i;
+ for (i = 0; i < num; i++)
+ if (msgs[i].flags & I2C_M_RD)
+ trace_i2c_read(adap, &msgs[i], i);
+ else
+ trace_i2c_write(adap, &msgs[i], i);
+ }
+
+ /* Retry automatically on arbitration loss */
+ orig_jiffies = jiffies;
+ for (ret = 0, try = 0; try <= adap->retries; try++) {
+ ret = adap->algo->master_xfer(adap, msgs, num);
+ if (ret != -EAGAIN)
+ break;
+ if (time_after(jiffies, orig_jiffies + adap->timeout))
+ break;
+ }
+
+ if (static_key_false(&i2c_trace_msg)) {
+ int i;
+ for (i = 0; i < ret; i++)
+ if (msgs[i].flags & I2C_M_RD)
+ trace_i2c_reply(adap, &msgs[i], i);
+ trace_i2c_result(adap, i, ret);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(__i2c_transfer);
+
+/**
+ * i2c_transfer - execute a single or combined I2C message
+ * @adap: Handle to I2C bus
+ * @msgs: One or more messages to execute before STOP is issued to
+ * terminate the operation; each message begins with a START.
+ * @num: Number of messages to be executed.
+ *
+ * Returns negative errno, else the number of messages executed.
+ *
+ * Note that there is no requirement that each message be sent to
+ * the same slave address, although that is the most common model.
+ */
+int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ int ret;
+
+ /* REVISIT the fault reporting model here is weak:
+ *
+ * - When we get an error after receiving N bytes from a slave,
+ * there is no way to report "N".
+ *
+ * - When we get a NAK after transmitting N bytes to a slave,
+ * there is no way to report "N" ... or to let the master
+ * continue executing the rest of this combined message, if
+ * that's the appropriate response.
+ *
+ * - When for example "num" is two and we successfully complete
+ * the first message but get an error part way through the
+ * second, it's unclear whether that should be reported as
+ * one (discarding status on the second message) or errno
+ * (discarding status on the first one).
+ */
+
+ if (adap->algo->master_xfer) {
+#ifdef DEBUG
+ for (ret = 0; ret < num; ret++) {
+ dev_dbg(&adap->dev,
+ "master_xfer[%d] %c, addr=0x%02x, len=%d%s\n",
+ ret, (msgs[ret].flags & I2C_M_RD) ? 'R' : 'W',
+ msgs[ret].addr, msgs[ret].len,
+ (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : "");
+ }
+#endif
+
+ if (in_atomic() || irqs_disabled()) {
+ ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT);
+ if (!ret)
+ /* I2C activity is ongoing. */
+ return -EAGAIN;
+ } else {
+ i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
+ }
+
+ ret = __i2c_transfer(adap, msgs, num);
+ i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
+
+ return ret;
+ } else {
+ dev_dbg(&adap->dev, "I2C level transfers not supported\n");
+ return -EOPNOTSUPP;
+ }
+}
+EXPORT_SYMBOL(i2c_transfer);
+
+/**
+ * i2c_master_send - issue a single I2C message in master transmit mode
+ * @client: Handle to slave device
+ * @buf: Data that will be written to the slave
+ * @count: How many bytes to write, must be less than 64k since msg.len is u16
+ *
+ * Returns negative errno, or else the number of bytes written.
+ */
+int i2c_master_send(const struct i2c_client *client, const char *buf, int count)
+{
+ int ret;
+ struct i2c_adapter *adap = client->adapter;
+ struct i2c_msg msg;
+
+ msg.addr = client->addr;
+ msg.flags = client->flags & I2C_M_TEN;
+ msg.len = count;
+ msg.buf = (char *)buf;
+
+ ret = i2c_transfer(adap, &msg, 1);
+
+ /*
+ * If everything went ok (i.e. 1 msg transmitted), return #bytes
+ * transmitted, else error code.
+ */
+ return (ret == 1) ? count : ret;
+}
+EXPORT_SYMBOL(i2c_master_send);
+
+/**
+ * i2c_master_recv - issue a single I2C message in master receive mode
+ * @client: Handle to slave device
+ * @buf: Where to store data read from slave
+ * @count: How many bytes to read, must be less than 64k since msg.len is u16
+ *
+ * Returns negative errno, or else the number of bytes read.
+ */
+int i2c_master_recv(const struct i2c_client *client, char *buf, int count)
+{
+ struct i2c_adapter *adap = client->adapter;
+ struct i2c_msg msg;
+ int ret;
+
+ msg.addr = client->addr;
+ msg.flags = client->flags & I2C_M_TEN;
+ msg.flags |= I2C_M_RD;
+ msg.len = count;
+ msg.buf = buf;
+
+ ret = i2c_transfer(adap, &msg, 1);
+
+ /*
+ * If everything went ok (i.e. 1 msg received), return #bytes received,
+ * else error code.
+ */
+ return (ret == 1) ? count : ret;
+}
+EXPORT_SYMBOL(i2c_master_recv);
+
+/* ----------------------------------------------------
+ * the i2c address scanning function
+ * Will not work for 10-bit addresses!
+ * ----------------------------------------------------
+ */
+
+/*
+ * Legacy default probe function, mostly relevant for SMBus. The default
+ * probe method is a quick write, but it is known to corrupt the 24RF08
+ * EEPROMs due to a state machine bug, and could also irreversibly
+ * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f,
+ * we use a short byte read instead. Also, some bus drivers don't implement
+ * quick write, so we fallback to a byte read in that case too.
+ * On x86, there is another special case for FSC hardware monitoring chips,
+ * which want regular byte reads (address 0x73.) Fortunately, these are the
+ * only known chips using this I2C address on PC hardware.
+ * Returns 1 if probe succeeded, 0 if not.
+ */
+static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
+{
+ int err;
+ union i2c_smbus_data dummy;
+
+#ifdef CONFIG_X86
+ if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON)
+ && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA))
+ err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
+ I2C_SMBUS_BYTE_DATA, &dummy);
+ else
+#endif
+ if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50)
+ && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
+ err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,
+ I2C_SMBUS_QUICK, NULL);
+ else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE))
+ err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
+ I2C_SMBUS_BYTE, &dummy);
+ else {
+ dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n",
+ addr);
+ err = -EOPNOTSUPP;
+ }
+
+ return err >= 0;
+}
+
+static int i2c_detect_address(struct i2c_client *temp_client,
+ struct i2c_driver *driver)
+{
+ struct i2c_board_info info;
+ struct i2c_adapter *adapter = temp_client->adapter;
+ int addr = temp_client->addr;
+ int err;
+
+ /* Make sure the address is valid */
+ err = i2c_check_7bit_addr_validity_strict(addr);
+ if (err) {
+ dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
+ addr);
+ return err;
+ }
+
+ /* Skip if already in use (7 bit, no need to encode flags) */
+ if (i2c_check_addr_busy(adapter, addr))
+ return 0;
+
+ /* Make sure there is something at this address */
+ if (!i2c_default_probe(adapter, addr))
+ return 0;
+
+ /* Finally call the custom detection function */
+ memset(&info, 0, sizeof(struct i2c_board_info));
+ info.addr = addr;
+ err = driver->detect(temp_client, &info);
+ if (err) {
+ /* -ENODEV is returned if the detection fails. We catch it
+ here as this isn't an error. */
+ return err == -ENODEV ? 0 : err;
+ }
+
+ /* Consistency check */
+ if (info.type[0] == '\0') {
+ dev_err(&adapter->dev,
+ "%s detection function provided no name for 0x%x\n",
+ driver->driver.name, addr);
+ } else {
+ struct i2c_client *client;
+
+ /* Detection succeeded, instantiate the device */
+ if (adapter->class & I2C_CLASS_DEPRECATED)
+ dev_warn(&adapter->dev,
+ "This adapter will soon drop class based instantiation of devices. "
+ "Please make sure client 0x%02x gets instantiated by other means. "
+ "Check 'Documentation/i2c/instantiating-devices' for details.\n",
+ info.addr);
+
+ dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
+ info.type, info.addr);
+ client = i2c_new_device(adapter, &info);
+ if (client)
+ list_add_tail(&client->detected, &driver->clients);
+ else
+ dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",
+ info.type, info.addr);
+ }
+ return 0;
+}
+
+static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
+{
+ const unsigned short *address_list;
+ struct i2c_client *temp_client;
+ int i, err = 0;
+ int adap_id = i2c_adapter_id(adapter);
+
+ address_list = driver->address_list;
+ if (!driver->detect || !address_list)
+ return 0;
+
+ /* Warn that the adapter lost class based instantiation */
+ if (adapter->class == I2C_CLASS_DEPRECATED) {
+ dev_dbg(&adapter->dev,
+ "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. "
+ "If you need it, check 'Documentation/i2c/instantiating-devices' for alternatives.\n",
+ driver->driver.name);
+ return 0;
+ }
+
+ /* Stop here if the classes do not match */
+ if (!(adapter->class & driver->class))
+ return 0;
+
+ /* Set up a temporary client to help detect callback */
+ temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
+ if (!temp_client)
+ return -ENOMEM;
+ temp_client->adapter = adapter;
+
+ for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
+ dev_dbg(&adapter->dev,
+ "found normal entry for adapter %d, addr 0x%02x\n",
+ adap_id, address_list[i]);
+ temp_client->addr = address_list[i];
+ err = i2c_detect_address(temp_client, driver);
+ if (unlikely(err))
+ break;
+ }
+
+ kfree(temp_client);
+ return err;
+}
+
+int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr)
+{
+ return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
+ I2C_SMBUS_QUICK, NULL) >= 0;
+}
+EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read);
+
+struct i2c_client *
+i2c_new_probed_device(struct i2c_adapter *adap,
+ struct i2c_board_info *info,
+ unsigned short const *addr_list,
+ int (*probe)(struct i2c_adapter *, unsigned short addr))
+{
+ int i;
+
+ if (!probe)
+ probe = i2c_default_probe;
+
+ for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
+ /* Check address validity */
+ if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {
+ dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n",
+ addr_list[i]);
+ continue;
+ }
+
+ /* Check address availability (7 bit, no need to encode flags) */
+ if (i2c_check_addr_busy(adap, addr_list[i])) {
+ dev_dbg(&adap->dev,
+ "Address 0x%02x already in use, not probing\n",
+ addr_list[i]);
+ continue;
+ }
+
+ /* Test address responsiveness */
+ if (probe(adap, addr_list[i]))
+ break;
+ }
+
+ if (addr_list[i] == I2C_CLIENT_END) {
+ dev_dbg(&adap->dev, "Probing failed, no device found\n");
+ return NULL;
+ }
+
+ info->addr = addr_list[i];
+ return i2c_new_device(adap, info);
+}
+EXPORT_SYMBOL_GPL(i2c_new_probed_device);
+
+struct i2c_adapter *i2c_get_adapter(int nr)
+{
+ struct i2c_adapter *adapter;
+
+ mutex_lock(&core_lock);
+ adapter = idr_find(&i2c_adapter_idr, nr);
+ if (!adapter)
+ goto exit;
+
+ if (try_module_get(adapter->owner))
+ get_device(&adapter->dev);
+ else
+ adapter = NULL;
+
+ exit:
+ mutex_unlock(&core_lock);
+ return adapter;
+}
+EXPORT_SYMBOL(i2c_get_adapter);
+
+void i2c_put_adapter(struct i2c_adapter *adap)
+{
+ if (!adap)
+ return;
+
+ put_device(&adap->dev);
+ module_put(adap->owner);
+}
+EXPORT_SYMBOL(i2c_put_adapter);
+
+/* The SMBus parts */
+
+#define POLY (0x1070U << 3)
+static u8 crc8(u16 data)
+{
+ int i;
+
+ for (i = 0; i < 8; i++) {
+ if (data & 0x8000)
+ data = data ^ POLY;
+ data = data << 1;
+ }
+ return (u8)(data >> 8);
+}
+
+/* Incremental CRC8 over count bytes in the array pointed to by p */
+static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
+{
+ int i;
+
+ for (i = 0; i < count; i++)
+ crc = crc8((crc ^ p[i]) << 8);
+ return crc;
+}
+
+/* Assume a 7-bit address, which is reasonable for SMBus */
+static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg)
+{
+ /* The address will be sent first */
+ u8 addr = i2c_8bit_addr_from_msg(msg);
+ pec = i2c_smbus_pec(pec, &addr, 1);
+
+ /* The data buffer follows */
+ return i2c_smbus_pec(pec, msg->buf, msg->len);
+}
+
+/* Used for write only transactions */
+static inline void i2c_smbus_add_pec(struct i2c_msg *msg)
+{
+ msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg);
+ msg->len++;
+}
+
+/* Return <0 on CRC error
+ If there was a write before this read (most cases) we need to take the
+ partial CRC from the write part into account.
+ Note that this function does modify the message (we need to decrease the
+ message length to hide the CRC byte from the caller). */
+static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg)
+{
+ u8 rpec = msg->buf[--msg->len];
+ cpec = i2c_smbus_msg_pec(cpec, msg);
+
+ if (rpec != cpec) {
+ pr_debug("Bad PEC 0x%02x vs. 0x%02x\n",
+ rpec, cpec);
+ return -EBADMSG;
+ }
+ return 0;
+}
+
+/**
+ * i2c_smbus_read_byte - SMBus "receive byte" protocol
+ * @client: Handle to slave device
+ *
+ * This executes the SMBus "receive byte" protocol, returning negative errno
+ * else the byte received from the device.
+ */
+s32 i2c_smbus_read_byte(const struct i2c_client *client)
+{
+ union i2c_smbus_data data;
+ int status;
+
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, 0,
+ I2C_SMBUS_BYTE, &data);
+ return (status < 0) ? status : data.byte;
+}
+EXPORT_SYMBOL(i2c_smbus_read_byte);
+
+/**
+ * i2c_smbus_write_byte - SMBus "send byte" protocol
+ * @client: Handle to slave device
+ * @value: Byte to be sent
+ *
+ * This executes the SMBus "send byte" protocol, returning negative errno
+ * else zero on success.
+ */
+s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value)
+{
+ return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
+}
+EXPORT_SYMBOL(i2c_smbus_write_byte);
+
+/**
+ * i2c_smbus_read_byte_data - SMBus "read byte" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ *
+ * This executes the SMBus "read byte" protocol, returning negative errno
+ * else a data byte received from the device.
+ */
+s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command)
+{
+ union i2c_smbus_data data;
+ int status;
+
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_BYTE_DATA, &data);
+ return (status < 0) ? status : data.byte;
+}
+EXPORT_SYMBOL(i2c_smbus_read_byte_data);
+
+/**
+ * i2c_smbus_write_byte_data - SMBus "write byte" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @value: Byte being written
+ *
+ * This executes the SMBus "write byte" protocol, returning negative errno
+ * else zero on success.
+ */
+s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command,
+ u8 value)
+{
+ union i2c_smbus_data data;
+ data.byte = value;
+ return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_WRITE, command,
+ I2C_SMBUS_BYTE_DATA, &data);
+}
+EXPORT_SYMBOL(i2c_smbus_write_byte_data);
+
+/**
+ * i2c_smbus_read_word_data - SMBus "read word" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ *
+ * This executes the SMBus "read word" protocol, returning negative errno
+ * else a 16-bit unsigned "word" received from the device.
+ */
+s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command)
+{
+ union i2c_smbus_data data;
+ int status;
+
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_WORD_DATA, &data);
+ return (status < 0) ? status : data.word;
+}
+EXPORT_SYMBOL(i2c_smbus_read_word_data);
+
+/**
+ * i2c_smbus_write_word_data - SMBus "write word" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @value: 16-bit "word" being written
+ *
+ * This executes the SMBus "write word" protocol, returning negative errno
+ * else zero on success.
+ */
+s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command,
+ u16 value)
+{
+ union i2c_smbus_data data;
+ data.word = value;
+ return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_WRITE, command,
+ I2C_SMBUS_WORD_DATA, &data);
+}
+EXPORT_SYMBOL(i2c_smbus_write_word_data);
+
+/**
+ * i2c_smbus_read_block_data - SMBus "block read" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @values: Byte array into which data will be read; big enough to hold
+ * the data returned by the slave. SMBus allows at most 32 bytes.
+ *
+ * This executes the SMBus "block read" protocol, returning negative errno
+ * else the number of data bytes in the slave's response.
+ *
+ * Note that using this function requires that the client's adapter support
+ * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers
+ * support this; its emulation through I2C messaging relies on a specific
+ * mechanism (I2C_M_RECV_LEN) which may not be implemented.
+ */
+s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command,
+ u8 *values)
+{
+ union i2c_smbus_data data;
+ int status;
+
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_BLOCK_DATA, &data);
+ if (status)
+ return status;
+
+ memcpy(values, &data.block[1], data.block[0]);
+ return data.block[0];
+}
+EXPORT_SYMBOL(i2c_smbus_read_block_data);
+
+/**
+ * i2c_smbus_write_block_data - SMBus "block write" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @length: Size of data block; SMBus allows at most 32 bytes
+ * @values: Byte array which will be written.
+ *
+ * This executes the SMBus "block write" protocol, returning negative errno
+ * else zero on success.
+ */
+s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command,
+ u8 length, const u8 *values)
+{
+ union i2c_smbus_data data;
+
+ if (length > I2C_SMBUS_BLOCK_MAX)
+ length = I2C_SMBUS_BLOCK_MAX;
+ data.block[0] = length;
+ memcpy(&data.block[1], values, length);
+ return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_WRITE, command,
+ I2C_SMBUS_BLOCK_DATA, &data);
+}
+EXPORT_SYMBOL(i2c_smbus_write_block_data);
+
+/* Returns the number of read bytes */
+s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command,
+ u8 length, u8 *values)
+{
+ union i2c_smbus_data data;
+ int status;
+
+ if (length > I2C_SMBUS_BLOCK_MAX)
+ length = I2C_SMBUS_BLOCK_MAX;
+ data.block[0] = length;
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_I2C_BLOCK_DATA, &data);
+ if (status < 0)
+ return status;
+
+ memcpy(values, &data.block[1], data.block[0]);
+ return data.block[0];
+}
+EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
+
+s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command,
+ u8 length, const u8 *values)
+{
+ union i2c_smbus_data data;
+
+ if (length > I2C_SMBUS_BLOCK_MAX)
+ length = I2C_SMBUS_BLOCK_MAX;
+ data.block[0] = length;
+ memcpy(data.block + 1, values, length);
+ return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_WRITE, command,
+ I2C_SMBUS_I2C_BLOCK_DATA, &data);
+}
+EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
+
+/* Simulate a SMBus command using the i2c protocol
+ No checking of parameters is done! */
+static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
+ unsigned short flags,
+ char read_write, u8 command, int size,
+ union i2c_smbus_data *data)
+{
+ /* So we need to generate a series of msgs. In the case of writing, we
+ need to use only one message; when reading, we need two. We initialize
+ most things with sane defaults, to keep the code below somewhat
+ simpler. */
+ unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
+ unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
+ int num = read_write == I2C_SMBUS_READ ? 2 : 1;
+ int i;
+ u8 partial_pec = 0;
+ int status;
+ struct i2c_msg msg[2] = {
+ {
+ .addr = addr,
+ .flags = flags,
+ .len = 1,
+ .buf = msgbuf0,
+ }, {
+ .addr = addr,
+ .flags = flags | I2C_M_RD,
+ .len = 0,
+ .buf = msgbuf1,
+ },
+ };
+
+ msgbuf0[0] = command;
+ switch (size) {
+ case I2C_SMBUS_QUICK:
+ msg[0].len = 0;
+ /* Special case: The read/write field is used as data */
+ msg[0].flags = flags | (read_write == I2C_SMBUS_READ ?
+ I2C_M_RD : 0);
+ num = 1;
+ break;
+ case I2C_SMBUS_BYTE:
+ if (read_write == I2C_SMBUS_READ) {
+ /* Special case: only a read! */
+ msg[0].flags = I2C_M_RD | flags;
+ num = 1;
+ }
+ break;
+ case I2C_SMBUS_BYTE_DATA:
+ if (read_write == I2C_SMBUS_READ)
+ msg[1].len = 1;
+ else {
+ msg[0].len = 2;
+ msgbuf0[1] = data->byte;
+ }
+ break;
+ case I2C_SMBUS_WORD_DATA:
+ if (read_write == I2C_SMBUS_READ)
+ msg[1].len = 2;
+ else {
+ msg[0].len = 3;
+ msgbuf0[1] = data->word & 0xff;
+ msgbuf0[2] = data->word >> 8;
+ }
+ break;
+ case I2C_SMBUS_PROC_CALL:
+ num = 2; /* Special case */
+ read_write = I2C_SMBUS_READ;
+ msg[0].len = 3;
+ msg[1].len = 2;
+ msgbuf0[1] = data->word & 0xff;
+ msgbuf0[2] = data->word >> 8;
+ break;
+ case I2C_SMBUS_BLOCK_DATA:
+ if (read_write == I2C_SMBUS_READ) {
+ msg[1].flags |= I2C_M_RECV_LEN;
+ msg[1].len = 1; /* block length will be added by
+ the underlying bus driver */
+ } else {
+ msg[0].len = data->block[0] + 2;
+ if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
+ dev_err(&adapter->dev,
+ "Invalid block write size %d\n",
+ data->block[0]);
+ return -EINVAL;
+ }
+ for (i = 1; i < msg[0].len; i++)
+ msgbuf0[i] = data->block[i-1];
+ }
+ break;
+ case I2C_SMBUS_BLOCK_PROC_CALL:
+ num = 2; /* Another special case */
+ read_write = I2C_SMBUS_READ;
+ if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
+ dev_err(&adapter->dev,
+ "Invalid block write size %d\n",
+ data->block[0]);
+ return -EINVAL;
+ }
+ msg[0].len = data->block[0] + 2;
+ for (i = 1; i < msg[0].len; i++)
+ msgbuf0[i] = data->block[i-1];
+ msg[1].flags |= I2C_M_RECV_LEN;
+ msg[1].len = 1; /* block length will be added by
+ the underlying bus driver */
+ break;
+ case I2C_SMBUS_I2C_BLOCK_DATA:
+ if (read_write == I2C_SMBUS_READ) {
+ msg[1].len = data->block[0];
+ } else {
+ msg[0].len = data->block[0] + 1;
+ if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) {
+ dev_err(&adapter->dev,
+ "Invalid block write size %d\n",
+ data->block[0]);
+ return -EINVAL;
+ }
+ for (i = 1; i <= data->block[0]; i++)
+ msgbuf0[i] = data->block[i];
+ }
+ break;
+ default:
+ dev_err(&adapter->dev, "Unsupported transaction %d\n", size);
+ return -EOPNOTSUPP;
+ }
+
+ i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK
+ && size != I2C_SMBUS_I2C_BLOCK_DATA);
+ if (i) {
+ /* Compute PEC if first message is a write */
+ if (!(msg[0].flags & I2C_M_RD)) {
+ if (num == 1) /* Write only */
+ i2c_smbus_add_pec(&msg[0]);
+ else /* Write followed by read */
+ partial_pec = i2c_smbus_msg_pec(0, &msg[0]);
+ }
+ /* Ask for PEC if last message is a read */
+ if (msg[num-1].flags & I2C_M_RD)
+ msg[num-1].len++;
+ }
+
+ status = i2c_transfer(adapter, msg, num);
+ if (status < 0)
+ return status;
+
+ /* Check PEC if last message is a read */
+ if (i && (msg[num-1].flags & I2C_M_RD)) {
+ status = i2c_smbus_check_pec(partial_pec, &msg[num-1]);
+ if (status < 0)
+ return status;
+ }
+
+ if (read_write == I2C_SMBUS_READ)
+ switch (size) {
+ case I2C_SMBUS_BYTE:
+ data->byte = msgbuf0[0];
+ break;
+ case I2C_SMBUS_BYTE_DATA:
+ data->byte = msgbuf1[0];
+ break;
+ case I2C_SMBUS_WORD_DATA:
+ case I2C_SMBUS_PROC_CALL:
+ data->word = msgbuf1[0] | (msgbuf1[1] << 8);
+ break;
+ case I2C_SMBUS_I2C_BLOCK_DATA:
+ for (i = 0; i < data->block[0]; i++)
+ data->block[i+1] = msgbuf1[i];
+ break;
+ case I2C_SMBUS_BLOCK_DATA:
+ case I2C_SMBUS_BLOCK_PROC_CALL:
+ for (i = 0; i < msgbuf1[0] + 1; i++)
+ data->block[i] = msgbuf1[i];
+ break;
+ }
+ return 0;
+}
+
+/**
+ * i2c_smbus_xfer - execute SMBus protocol operations
+ * @adapter: Handle to I2C bus
+ * @addr: Address of SMBus slave on that bus
+ * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC)
+ * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE
+ * @command: Byte interpreted by slave, for protocols which use such bytes
+ * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL
+ * @data: Data to be read or written
+ *
+ * This executes an SMBus protocol operation, and returns a negative
+ * errno code else zero on success.
+ */
+s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
+ char read_write, u8 command, int protocol,
+ union i2c_smbus_data *data)
+{
+ unsigned long orig_jiffies;
+ int try;
+ s32 res;
+
+ /* If enabled, the following two tracepoints are conditional on
+ * read_write and protocol.
+ */
+ trace_smbus_write(adapter, addr, flags, read_write,
+ command, protocol, data);
+ trace_smbus_read(adapter, addr, flags, read_write,
+ command, protocol);
+
+ flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB;
+
+ if (adapter->algo->smbus_xfer) {
+ i2c_lock_bus(adapter, I2C_LOCK_SEGMENT);
+
+ /* Retry automatically on arbitration loss */
+ orig_jiffies = jiffies;
+ for (res = 0, try = 0; try <= adapter->retries; try++) {
+ res = adapter->algo->smbus_xfer(adapter, addr, flags,
+ read_write, command,
+ protocol, data);
+ if (res != -EAGAIN)
+ break;
+ if (time_after(jiffies,
+ orig_jiffies + adapter->timeout))
+ break;
+ }
+ i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT);
+
+ if (res != -EOPNOTSUPP || !adapter->algo->master_xfer)
+ goto trace;
+ /*
+ * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't
+ * implement native support for the SMBus operation.
+ */
+ }
+
+ res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write,
+ command, protocol, data);
+
+trace:
+ /* If enabled, the reply tracepoint is conditional on read_write. */
+ trace_smbus_reply(adapter, addr, flags, read_write,
+ command, protocol, data);
+ trace_smbus_result(adapter, addr, flags, read_write,
+ command, protocol, res);
+
+ return res;
+}
+EXPORT_SYMBOL(i2c_smbus_xfer);
+
+/**
+ * i2c_smbus_read_i2c_block_data_or_emulated - read block or emulate
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @length: Size of data block; SMBus allows at most I2C_SMBUS_BLOCK_MAX bytes
+ * @values: Byte array into which data will be read; big enough to hold
+ * the data returned by the slave. SMBus allows at most
+ * I2C_SMBUS_BLOCK_MAX bytes.
+ *
+ * This executes the SMBus "block read" protocol if supported by the adapter.
+ * If block read is not supported, it emulates it using either word or byte
+ * read protocols depending on availability.
+ *
+ * The addresses of the I2C slave device that are accessed with this function
+ * must be mapped to a linear region, so that a block read will have the same
+ * effect as a byte read. Before using this function you must double-check
+ * if the I2C slave does support exchanging a block transfer with a byte
+ * transfer.
+ */
+s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
+ u8 command, u8 length, u8 *values)
+{
+ u8 i = 0;
+ int status;
+
+ if (length > I2C_SMBUS_BLOCK_MAX)
+ length = I2C_SMBUS_BLOCK_MAX;
+
+ if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
+ return i2c_smbus_read_i2c_block_data(client, command, length, values);
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA))
+ return -EOPNOTSUPP;
+
+ if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)) {
+ while ((i + 2) <= length) {
+ status = i2c_smbus_read_word_data(client, command + i);
+ if (status < 0)
+ return status;
+ values[i] = status & 0xff;
+ values[i + 1] = status >> 8;
+ i += 2;
+ }
+ }
+
+ while (i < length) {
+ status = i2c_smbus_read_byte_data(client, command + i);
+ if (status < 0)
+ return status;
+ values[i] = status;
+ i++;
+ }
+
+ return i;
+}
+EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data_or_emulated);
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb)
+{
+ int ret;
+
+ if (!client || !slave_cb) {
+ WARN(1, "insufficient data\n");
+ return -EINVAL;
+ }
+
+ if (!(client->flags & I2C_CLIENT_SLAVE))
+ dev_warn(&client->dev, "%s: client slave flag not set. You might see address collisions\n",
+ __func__);
+
+ if (!(client->flags & I2C_CLIENT_TEN)) {
+ /* Enforce stricter address checking */
+ ret = i2c_check_7bit_addr_validity_strict(client->addr);
+ if (ret) {
+ dev_err(&client->dev, "%s: invalid address\n", __func__);
+ return ret;
+ }
+ }
+
+ if (!client->adapter->algo->reg_slave) {
+ dev_err(&client->dev, "%s: not supported by adapter\n", __func__);
+ return -EOPNOTSUPP;
+ }
+
+ client->slave_cb = slave_cb;
+
+ i2c_lock_adapter(client->adapter);
+ ret = client->adapter->algo->reg_slave(client);
+ i2c_unlock_adapter(client->adapter);
+
+ if (ret) {
+ client->slave_cb = NULL;
+ dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(i2c_slave_register);
+
+int i2c_slave_unregister(struct i2c_client *client)
+{
+ int ret;
+
+ if (!client->adapter->algo->unreg_slave) {
+ dev_err(&client->dev, "%s: not supported by adapter\n", __func__);
+ return -EOPNOTSUPP;
+ }
+
+ i2c_lock_adapter(client->adapter);
+ ret = client->adapter->algo->unreg_slave(client);
+ i2c_unlock_adapter(client->adapter);
+
+ if (ret == 0)
+ client->slave_cb = NULL;
+ else
+ dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(i2c_slave_unregister);
+
+/**
+ * i2c_detect_slave_mode - detect operation mode
+ * @dev: The device owning the bus
+ *
+ * This checks the device nodes for an I2C slave by checking the address
+ * used in the reg property. If the address match the I2C_OWN_SLAVE_ADDRESS
+ * flag this means the device is configured to act as a I2C slave and it will
+ * be listening at that address.
+ *
+ * Returns true if an I2C own slave address is detected, otherwise returns
+ * false.
+ */
+bool i2c_detect_slave_mode(struct device *dev)
+{
+ if (IS_BUILTIN(CONFIG_OF) && dev->of_node) {
+ struct device_node *child;
+ u32 reg;
+
+ for_each_child_of_node(dev->of_node, child) {
+ of_property_read_u32(child, "reg", ®);
+ if (reg & I2C_OWN_SLAVE_ADDRESS) {
+ of_node_put(child);
+ return true;
+ }
+ }
+ } else if (IS_BUILTIN(CONFIG_ACPI) && ACPI_HANDLE(dev)) {
+ dev_dbg(dev, "ACPI slave is not supported yet\n");
+ }
+ return false;
+}
+EXPORT_SYMBOL_GPL(i2c_detect_slave_mode);
+
+#endif
+
+MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
+MODULE_DESCRIPTION("I2C-Bus main module");
+MODULE_LICENSE("GPL");
+++ /dev/null
-/* i2c-core.c - a device driver for the iic-bus interface */
-/* ------------------------------------------------------------------------- */
-/* Copyright (C) 1995-99 Simon G. Vogl
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details. */
-/* ------------------------------------------------------------------------- */
-
-/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
- All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
- SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and
- Jean Delvare <jdelvare@suse.de>
- Mux support by Rodolfo Giometti <giometti@enneenne.com> and
- Michael Lawnick <michael.lawnick.ext@nsn.com>
- OF support is copyright (c) 2008 Jochen Friedrich <jochen@scram.de>
- (based on a previous patch from Jon Smirl <jonsmirl@gmail.com>) and
- (c) 2013 Wolfram Sang <wsa@the-dreams.de>
- I2C ACPI code Copyright (C) 2014 Intel Corp
- Author: Lan Tianyu <tianyu.lan@intel.com>
- I2C slave support (c) 2014 by Wolfram Sang <wsa@sang-engineering.com>
- */
-
-#define pr_fmt(fmt) "i2c-core: " fmt
-
-#include <dt-bindings/i2c/i2c.h>
-#include <linux/uaccess.h>
-#include <linux/acpi.h>
-#include <linux/clk/clk-conf.h>
-#include <linux/completion.h>
-#include <linux/delay.h>
-#include <linux/err.h>
-#include <linux/errno.h>
-#include <linux/gpio.h>
-#include <linux/hardirq.h>
-#include <linux/i2c.h>
-#include <linux/idr.h>
-#include <linux/init.h>
-#include <linux/irqflags.h>
-#include <linux/jump_label.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/of_device.h>
-#include <linux/of.h>
-#include <linux/of_irq.h>
-#include <linux/pm_domain.h>
-#include <linux/pm_runtime.h>
-#include <linux/pm_wakeirq.h>
-#include <linux/property.h>
-#include <linux/rwsem.h>
-#include <linux/slab.h>
-
-#include "i2c-core.h"
-
-#define CREATE_TRACE_POINTS
-#include <trace/events/i2c.h>
-
-#define I2C_ADDR_OFFSET_TEN_BIT 0xa000
-#define I2C_ADDR_OFFSET_SLAVE 0x1000
-
-#define I2C_ADDR_7BITS_MAX 0x77
-#define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1)
-
-/* core_lock protects i2c_adapter_idr, and guarantees
- that device detection, deletion of detected devices, and attach_adapter
- calls are serialized */
-static DEFINE_MUTEX(core_lock);
-static DEFINE_IDR(i2c_adapter_idr);
-
-static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
-
-static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE;
-static bool is_registered;
-
-int i2c_transfer_trace_reg(void)
-{
- static_key_slow_inc(&i2c_trace_msg);
- return 0;
-}
-
-void i2c_transfer_trace_unreg(void)
-{
- static_key_slow_dec(&i2c_trace_msg);
-}
-
-#if defined(CONFIG_ACPI)
-struct i2c_acpi_handler_data {
- struct acpi_connection_info info;
- struct i2c_adapter *adapter;
-};
-
-struct gsb_buffer {
- u8 status;
- u8 len;
- union {
- u16 wdata;
- u8 bdata;
- u8 data[0];
- };
-} __packed;
-
-struct i2c_acpi_lookup {
- struct i2c_board_info *info;
- acpi_handle adapter_handle;
- acpi_handle device_handle;
- acpi_handle search_handle;
- int n;
- int index;
- u32 speed;
- u32 min_speed;
-};
-
-static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)
-{
- struct i2c_acpi_lookup *lookup = data;
- struct i2c_board_info *info = lookup->info;
- struct acpi_resource_i2c_serialbus *sb;
- acpi_status status;
-
- if (info->addr || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
- return 1;
-
- sb = &ares->data.i2c_serial_bus;
- if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
- return 1;
-
- if (lookup->index != -1 && lookup->n++ != lookup->index)
- return 1;
-
- status = acpi_get_handle(lookup->device_handle,
- sb->resource_source.string_ptr,
- &lookup->adapter_handle);
- if (!ACPI_SUCCESS(status))
- return 1;
-
- info->addr = sb->slave_address;
- lookup->speed = sb->connection_speed;
- if (sb->access_mode == ACPI_I2C_10BIT_MODE)
- info->flags |= I2C_CLIENT_TEN;
-
- return 1;
-}
-
-static int i2c_acpi_do_lookup(struct acpi_device *adev,
- struct i2c_acpi_lookup *lookup)
-{
- struct i2c_board_info *info = lookup->info;
- struct list_head resource_list;
- int ret;
-
- if (acpi_bus_get_status(adev) || !adev->status.present ||
- acpi_device_enumerated(adev))
- return -EINVAL;
-
- memset(info, 0, sizeof(*info));
- lookup->device_handle = acpi_device_handle(adev);
-
- /* Look up for I2cSerialBus resource */
- INIT_LIST_HEAD(&resource_list);
- ret = acpi_dev_get_resources(adev, &resource_list,
- i2c_acpi_fill_info, lookup);
- acpi_dev_free_resource_list(&resource_list);
-
- if (ret < 0 || !info->addr)
- return -EINVAL;
-
- return 0;
-}
-
-static int i2c_acpi_get_info(struct acpi_device *adev,
- struct i2c_board_info *info,
- struct i2c_adapter *adapter,
- acpi_handle *adapter_handle)
-{
- struct list_head resource_list;
- struct resource_entry *entry;
- struct i2c_acpi_lookup lookup;
- int ret;
-
- memset(&lookup, 0, sizeof(lookup));
- lookup.info = info;
- lookup.index = -1;
-
- ret = i2c_acpi_do_lookup(adev, &lookup);
- if (ret)
- return ret;
-
- if (adapter) {
- /* The adapter must match the one in I2cSerialBus() connector */
- if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)
- return -ENODEV;
- } else {
- struct acpi_device *adapter_adev;
-
- /* The adapter must be present */
- if (acpi_bus_get_device(lookup.adapter_handle, &adapter_adev))
- return -ENODEV;
- if (acpi_bus_get_status(adapter_adev) ||
- !adapter_adev->status.present)
- return -ENODEV;
- }
-
- info->fwnode = acpi_fwnode_handle(adev);
- if (adapter_handle)
- *adapter_handle = lookup.adapter_handle;
-
- /* Then fill IRQ number if any */
- INIT_LIST_HEAD(&resource_list);
- ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
- if (ret < 0)
- return -EINVAL;
-
- resource_list_for_each_entry(entry, &resource_list) {
- if (resource_type(entry->res) == IORESOURCE_IRQ) {
- info->irq = entry->res->start;
- break;
- }
- }
-
- acpi_dev_free_resource_list(&resource_list);
-
- acpi_set_modalias(adev, dev_name(&adev->dev), info->type,
- sizeof(info->type));
-
- return 0;
-}
-
-static void i2c_acpi_register_device(struct i2c_adapter *adapter,
- struct acpi_device *adev,
- struct i2c_board_info *info)
-{
- adev->power.flags.ignore_parent = true;
- acpi_device_set_enumerated(adev);
-
- if (!i2c_new_device(adapter, info)) {
- adev->power.flags.ignore_parent = false;
- dev_err(&adapter->dev,
- "failed to add I2C device %s from ACPI\n",
- dev_name(&adev->dev));
- }
-}
-
-static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
- void *data, void **return_value)
-{
- struct i2c_adapter *adapter = data;
- struct acpi_device *adev;
- struct i2c_board_info info;
-
- if (acpi_bus_get_device(handle, &adev))
- return AE_OK;
-
- if (i2c_acpi_get_info(adev, &info, adapter, NULL))
- return AE_OK;
-
- i2c_acpi_register_device(adapter, adev, &info);
-
- return AE_OK;
-}
-
-#define I2C_ACPI_MAX_SCAN_DEPTH 32
-
-/**
- * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter
- * @adap: pointer to adapter
- *
- * Enumerate all I2C slave devices behind this adapter by walking the ACPI
- * namespace. When a device is found it will be added to the Linux device
- * model and bound to the corresponding ACPI handle.
- */
-static void i2c_acpi_register_devices(struct i2c_adapter *adap)
-{
- acpi_status status;
-
- if (!has_acpi_companion(&adap->dev))
- return;
-
- status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
- I2C_ACPI_MAX_SCAN_DEPTH,
- i2c_acpi_add_device, NULL,
- adap, NULL);
- if (ACPI_FAILURE(status))
- dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
-}
-
-static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,
- void *data, void **return_value)
-{
- struct i2c_acpi_lookup *lookup = data;
- struct acpi_device *adev;
-
- if (acpi_bus_get_device(handle, &adev))
- return AE_OK;
-
- if (i2c_acpi_do_lookup(adev, lookup))
- return AE_OK;
-
- if (lookup->search_handle != lookup->adapter_handle)
- return AE_OK;
-
- if (lookup->speed <= lookup->min_speed)
- lookup->min_speed = lookup->speed;
-
- return AE_OK;
-}
-
-/**
- * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI
- * @dev: The device owning the bus
- *
- * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves
- * devices connected to this bus and use the speed of slowest device.
- *
- * Returns the speed in Hz or zero
- */
-u32 i2c_acpi_find_bus_speed(struct device *dev)
-{
- struct i2c_acpi_lookup lookup;
- struct i2c_board_info dummy;
- acpi_status status;
-
- if (!has_acpi_companion(dev))
- return 0;
-
- memset(&lookup, 0, sizeof(lookup));
- lookup.search_handle = ACPI_HANDLE(dev);
- lookup.min_speed = UINT_MAX;
- lookup.info = &dummy;
- lookup.index = -1;
-
- status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
- I2C_ACPI_MAX_SCAN_DEPTH,
- i2c_acpi_lookup_speed, NULL,
- &lookup, NULL);
-
- if (ACPI_FAILURE(status)) {
- dev_warn(dev, "unable to find I2C bus speed from ACPI\n");
- return 0;
- }
-
- return lookup.min_speed != UINT_MAX ? lookup.min_speed : 0;
-}
-EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);
-
-static int i2c_acpi_match_adapter(struct device *dev, void *data)
-{
- struct i2c_adapter *adapter = i2c_verify_adapter(dev);
-
- if (!adapter)
- return 0;
-
- return ACPI_HANDLE(dev) == (acpi_handle)data;
-}
-
-static int i2c_acpi_match_device(struct device *dev, void *data)
-{
- return ACPI_COMPANION(dev) == data;
-}
-
-static struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
-{
- struct device *dev;
-
- dev = bus_find_device(&i2c_bus_type, NULL, handle,
- i2c_acpi_match_adapter);
- return dev ? i2c_verify_adapter(dev) : NULL;
-}
-
-static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)
-{
- struct device *dev;
-
- dev = bus_find_device(&i2c_bus_type, NULL, adev, i2c_acpi_match_device);
- return dev ? i2c_verify_client(dev) : NULL;
-}
-
-static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,
- void *arg)
-{
- struct acpi_device *adev = arg;
- struct i2c_board_info info;
- acpi_handle adapter_handle;
- struct i2c_adapter *adapter;
- struct i2c_client *client;
-
- switch (value) {
- case ACPI_RECONFIG_DEVICE_ADD:
- if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))
- break;
-
- adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);
- if (!adapter)
- break;
-
- i2c_acpi_register_device(adapter, adev, &info);
- break;
- case ACPI_RECONFIG_DEVICE_REMOVE:
- if (!acpi_device_enumerated(adev))
- break;
-
- client = i2c_acpi_find_client_by_adev(adev);
- if (!client)
- break;
-
- i2c_unregister_device(client);
- put_device(&client->dev);
- break;
- }
-
- return NOTIFY_OK;
-}
-
-static struct notifier_block i2c_acpi_notifier = {
- .notifier_call = i2c_acpi_notify,
-};
-
-/**
- * i2c_acpi_new_device - Create i2c-client for the Nth I2cSerialBus resource
- * @dev: Device owning the ACPI resources to get the client from
- * @index: Index of ACPI resource to get
- * @info: describes the I2C device; note this is modified (addr gets set)
- * Context: can sleep
- *
- * By default the i2c subsys creates an i2c-client for the first I2cSerialBus
- * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus
- * resources, in that case this function can be used to create an i2c-client
- * for other I2cSerialBus resources in the Current Resource Settings table.
- *
- * Also see i2c_new_device, which this function calls to create the i2c-client.
- *
- * Returns a pointer to the new i2c-client, or NULL if the adapter is not found.
- */
-struct i2c_client *i2c_acpi_new_device(struct device *dev, int index,
- struct i2c_board_info *info)
-{
- struct i2c_acpi_lookup lookup;
- struct i2c_adapter *adapter;
- struct acpi_device *adev;
- LIST_HEAD(resource_list);
- int ret;
-
- adev = ACPI_COMPANION(dev);
- if (!adev)
- return NULL;
-
- memset(&lookup, 0, sizeof(lookup));
- lookup.info = info;
- lookup.device_handle = acpi_device_handle(adev);
- lookup.index = index;
-
- ret = acpi_dev_get_resources(adev, &resource_list,
- i2c_acpi_fill_info, &lookup);
- acpi_dev_free_resource_list(&resource_list);
-
- if (ret < 0 || !info->addr)
- return NULL;
-
- adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);
- if (!adapter)
- return NULL;
-
- return i2c_new_device(adapter, info);
-}
-EXPORT_SYMBOL_GPL(i2c_acpi_new_device);
-#else /* CONFIG_ACPI */
-static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
-extern struct notifier_block i2c_acpi_notifier;
-#endif /* CONFIG_ACPI */
-
-#ifdef CONFIG_ACPI_I2C_OPREGION
-static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
- u8 cmd, u8 *data, u8 data_len)
-{
-
- struct i2c_msg msgs[2];
- int ret;
- u8 *buffer;
-
- buffer = kzalloc(data_len, GFP_KERNEL);
- if (!buffer)
- return AE_NO_MEMORY;
-
- msgs[0].addr = client->addr;
- msgs[0].flags = client->flags;
- msgs[0].len = 1;
- msgs[0].buf = &cmd;
-
- msgs[1].addr = client->addr;
- msgs[1].flags = client->flags | I2C_M_RD;
- msgs[1].len = data_len;
- msgs[1].buf = buffer;
-
- ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
- if (ret < 0)
- dev_err(&client->adapter->dev, "i2c read failed\n");
- else
- memcpy(data, buffer, data_len);
-
- kfree(buffer);
- return ret;
-}
-
-static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
- u8 cmd, u8 *data, u8 data_len)
-{
-
- struct i2c_msg msgs[1];
- u8 *buffer;
- int ret = AE_OK;
-
- buffer = kzalloc(data_len + 1, GFP_KERNEL);
- if (!buffer)
- return AE_NO_MEMORY;
-
- buffer[0] = cmd;
- memcpy(buffer + 1, data, data_len);
-
- msgs[0].addr = client->addr;
- msgs[0].flags = client->flags;
- msgs[0].len = data_len + 1;
- msgs[0].buf = buffer;
-
- ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
- if (ret < 0)
- dev_err(&client->adapter->dev, "i2c write failed\n");
-
- kfree(buffer);
- return ret;
-}
-
-static acpi_status
-i2c_acpi_space_handler(u32 function, acpi_physical_address command,
- u32 bits, u64 *value64,
- void *handler_context, void *region_context)
-{
- struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
- struct i2c_acpi_handler_data *data = handler_context;
- struct acpi_connection_info *info = &data->info;
- struct acpi_resource_i2c_serialbus *sb;
- struct i2c_adapter *adapter = data->adapter;
- struct i2c_client *client;
- struct acpi_resource *ares;
- u32 accessor_type = function >> 16;
- u8 action = function & ACPI_IO_MASK;
- acpi_status ret;
- int status;
-
- ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
- if (ACPI_FAILURE(ret))
- return ret;
-
- client = kzalloc(sizeof(*client), GFP_KERNEL);
- if (!client) {
- ret = AE_NO_MEMORY;
- goto err;
- }
-
- if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) {
- ret = AE_BAD_PARAMETER;
- goto err;
- }
-
- sb = &ares->data.i2c_serial_bus;
- if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) {
- ret = AE_BAD_PARAMETER;
- goto err;
- }
-
- client->adapter = adapter;
- client->addr = sb->slave_address;
-
- if (sb->access_mode == ACPI_I2C_10BIT_MODE)
- client->flags |= I2C_CLIENT_TEN;
-
- switch (accessor_type) {
- case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
- if (action == ACPI_READ) {
- status = i2c_smbus_read_byte(client);
- if (status >= 0) {
- gsb->bdata = status;
- status = 0;
- }
- } else {
- status = i2c_smbus_write_byte(client, gsb->bdata);
- }
- break;
-
- case ACPI_GSB_ACCESS_ATTRIB_BYTE:
- if (action == ACPI_READ) {
- status = i2c_smbus_read_byte_data(client, command);
- if (status >= 0) {
- gsb->bdata = status;
- status = 0;
- }
- } else {
- status = i2c_smbus_write_byte_data(client, command,
- gsb->bdata);
- }
- break;
-
- case ACPI_GSB_ACCESS_ATTRIB_WORD:
- if (action == ACPI_READ) {
- status = i2c_smbus_read_word_data(client, command);
- if (status >= 0) {
- gsb->wdata = status;
- status = 0;
- }
- } else {
- status = i2c_smbus_write_word_data(client, command,
- gsb->wdata);
- }
- break;
-
- case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
- if (action == ACPI_READ) {
- status = i2c_smbus_read_block_data(client, command,
- gsb->data);
- if (status >= 0) {
- gsb->len = status;
- status = 0;
- }
- } else {
- status = i2c_smbus_write_block_data(client, command,
- gsb->len, gsb->data);
- }
- break;
-
- case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
- if (action == ACPI_READ) {
- status = acpi_gsb_i2c_read_bytes(client, command,
- gsb->data, info->access_length);
- if (status > 0)
- status = 0;
- } else {
- status = acpi_gsb_i2c_write_bytes(client, command,
- gsb->data, info->access_length);
- }
- break;
-
- default:
- dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
- accessor_type, client->addr);
- ret = AE_BAD_PARAMETER;
- goto err;
- }
-
- gsb->status = status;
-
- err:
- kfree(client);
- ACPI_FREE(ares);
- return ret;
-}
-
-
-static int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
-{
- acpi_handle handle;
- struct i2c_acpi_handler_data *data;
- acpi_status status;
-
- if (!adapter->dev.parent)
- return -ENODEV;
-
- handle = ACPI_HANDLE(adapter->dev.parent);
-
- if (!handle)
- return -ENODEV;
-
- data = kzalloc(sizeof(struct i2c_acpi_handler_data),
- GFP_KERNEL);
- if (!data)
- return -ENOMEM;
-
- data->adapter = adapter;
- status = acpi_bus_attach_private_data(handle, (void *)data);
- if (ACPI_FAILURE(status)) {
- kfree(data);
- return -ENOMEM;
- }
-
- status = acpi_install_address_space_handler(handle,
- ACPI_ADR_SPACE_GSBUS,
- &i2c_acpi_space_handler,
- NULL,
- data);
- if (ACPI_FAILURE(status)) {
- dev_err(&adapter->dev, "Error installing i2c space handler\n");
- acpi_bus_detach_private_data(handle);
- kfree(data);
- return -ENOMEM;
- }
-
- acpi_walk_dep_device_list(handle);
- return 0;
-}
-
-static void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
-{
- acpi_handle handle;
- struct i2c_acpi_handler_data *data;
- acpi_status status;
-
- if (!adapter->dev.parent)
- return;
-
- handle = ACPI_HANDLE(adapter->dev.parent);
-
- if (!handle)
- return;
-
- acpi_remove_address_space_handler(handle,
- ACPI_ADR_SPACE_GSBUS,
- &i2c_acpi_space_handler);
-
- status = acpi_bus_get_private_data(handle, (void **)&data);
- if (ACPI_SUCCESS(status))
- kfree(data);
-
- acpi_bus_detach_private_data(handle);
-}
-#else /* CONFIG_ACPI_I2C_OPREGION */
-static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)
-{ }
-
-static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)
-{ return 0; }
-#endif /* CONFIG_ACPI_I2C_OPREGION */
-
-/* ------------------------------------------------------------------------- */
-
-const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
- const struct i2c_client *client)
-{
- if (!(id && client))
- return NULL;
-
- while (id->name[0]) {
- if (strcmp(client->name, id->name) == 0)
- return id;
- id++;
- }
- return NULL;
-}
-EXPORT_SYMBOL_GPL(i2c_match_id);
-
-static int i2c_device_match(struct device *dev, struct device_driver *drv)
-{
- struct i2c_client *client = i2c_verify_client(dev);
- struct i2c_driver *driver;
-
-
- /* Attempt an OF style match */
- if (i2c_of_match_device(drv->of_match_table, client))
- return 1;
-
- /* Then ACPI style match */
- if (acpi_driver_match_device(dev, drv))
- return 1;
-
- driver = to_i2c_driver(drv);
-
- /* Finally an I2C match */
- if (i2c_match_id(driver->id_table, client))
- return 1;
-
- return 0;
-}
-
-static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
-{
- struct i2c_client *client = to_i2c_client(dev);
- int rc;
-
- rc = acpi_device_uevent_modalias(dev, env);
- if (rc != -ENODEV)
- return rc;
-
- return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name);
-}
-
-/* i2c bus recovery routines */
-static int get_scl_gpio_value(struct i2c_adapter *adap)
-{
- return gpio_get_value(adap->bus_recovery_info->scl_gpio);
-}
-
-static void set_scl_gpio_value(struct i2c_adapter *adap, int val)
-{
- gpio_set_value(adap->bus_recovery_info->scl_gpio, val);
-}
-
-static int get_sda_gpio_value(struct i2c_adapter *adap)
-{
- return gpio_get_value(adap->bus_recovery_info->sda_gpio);
-}
-
-static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap)
-{
- struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
- struct device *dev = &adap->dev;
- int ret = 0;
-
- ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN |
- GPIOF_OUT_INIT_HIGH, "i2c-scl");
- if (ret) {
- dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio);
- return ret;
- }
-
- if (bri->get_sda) {
- if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) {
- /* work without SDA polling */
- dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n",
- bri->sda_gpio);
- bri->get_sda = NULL;
- }
- }
-
- return ret;
-}
-
-static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap)
-{
- struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
-
- if (bri->get_sda)
- gpio_free(bri->sda_gpio);
-
- gpio_free(bri->scl_gpio);
-}
-
-/*
- * We are generating clock pulses. ndelay() determines durating of clk pulses.
- * We will generate clock with rate 100 KHz and so duration of both clock levels
- * is: delay in ns = (10^6 / 100) / 2
- */
-#define RECOVERY_NDELAY 5000
-#define RECOVERY_CLK_CNT 9
-
-static int i2c_generic_recovery(struct i2c_adapter *adap)
-{
- struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
- int i = 0, val = 1, ret = 0;
-
- if (bri->prepare_recovery)
- bri->prepare_recovery(adap);
-
- bri->set_scl(adap, val);
- ndelay(RECOVERY_NDELAY);
-
- /*
- * By this time SCL is high, as we need to give 9 falling-rising edges
- */
- while (i++ < RECOVERY_CLK_CNT * 2) {
- if (val) {
- /* Break if SDA is high */
- if (bri->get_sda && bri->get_sda(adap))
- break;
- /* SCL shouldn't be low here */
- if (!bri->get_scl(adap)) {
- dev_err(&adap->dev,
- "SCL is stuck low, exit recovery\n");
- ret = -EBUSY;
- break;
- }
- }
-
- val = !val;
- bri->set_scl(adap, val);
- ndelay(RECOVERY_NDELAY);
- }
-
- if (bri->unprepare_recovery)
- bri->unprepare_recovery(adap);
-
- return ret;
-}
-
-int i2c_generic_scl_recovery(struct i2c_adapter *adap)
-{
- return i2c_generic_recovery(adap);
-}
-EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
-
-int i2c_generic_gpio_recovery(struct i2c_adapter *adap)
-{
- int ret;
-
- ret = i2c_get_gpios_for_recovery(adap);
- if (ret)
- return ret;
-
- ret = i2c_generic_recovery(adap);
- i2c_put_gpios_for_recovery(adap);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(i2c_generic_gpio_recovery);
-
-int i2c_recover_bus(struct i2c_adapter *adap)
-{
- if (!adap->bus_recovery_info)
- return -EOPNOTSUPP;
-
- dev_dbg(&adap->dev, "Trying i2c bus recovery\n");
- return adap->bus_recovery_info->recover_bus(adap);
-}
-EXPORT_SYMBOL_GPL(i2c_recover_bus);
-
-static void i2c_init_recovery(struct i2c_adapter *adap)
-{
- struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
- char *err_str;
-
- if (!bri)
- return;
-
- if (!bri->recover_bus) {
- err_str = "no recover_bus() found";
- goto err;
- }
-
- /* Generic GPIO recovery */
- if (bri->recover_bus == i2c_generic_gpio_recovery) {
- if (!gpio_is_valid(bri->scl_gpio)) {
- err_str = "invalid SCL gpio";
- goto err;
- }
-
- if (gpio_is_valid(bri->sda_gpio))
- bri->get_sda = get_sda_gpio_value;
- else
- bri->get_sda = NULL;
-
- bri->get_scl = get_scl_gpio_value;
- bri->set_scl = set_scl_gpio_value;
- } else if (bri->recover_bus == i2c_generic_scl_recovery) {
- /* Generic SCL recovery */
- if (!bri->set_scl || !bri->get_scl) {
- err_str = "no {get|set}_scl() found";
- goto err;
- }
- }
-
- return;
- err:
- dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
- adap->bus_recovery_info = NULL;
-}
-
-static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)
-{
- struct i2c_adapter *adap = client->adapter;
- unsigned int irq;
-
- if (!adap->host_notify_domain)
- return -ENXIO;
-
- if (client->flags & I2C_CLIENT_TEN)
- return -EINVAL;
-
- irq = irq_find_mapping(adap->host_notify_domain, client->addr);
- if (!irq)
- irq = irq_create_mapping(adap->host_notify_domain,
- client->addr);
-
- return irq > 0 ? irq : -ENXIO;
-}
-
-static int i2c_device_probe(struct device *dev)
-{
- struct i2c_client *client = i2c_verify_client(dev);
- struct i2c_driver *driver;
- int status;
-
- if (!client)
- return 0;
-
- driver = to_i2c_driver(dev->driver);
-
- if (!client->irq && !driver->disable_i2c_core_irq_mapping) {
- int irq = -ENOENT;
-
- if (client->flags & I2C_CLIENT_HOST_NOTIFY) {
- dev_dbg(dev, "Using Host Notify IRQ\n");
- irq = i2c_smbus_host_notify_to_irq(client);
- } else if (dev->of_node) {
- irq = of_irq_get_byname(dev->of_node, "irq");
- if (irq == -EINVAL || irq == -ENODATA)
- irq = of_irq_get(dev->of_node, 0);
- } else if (ACPI_COMPANION(dev)) {
- irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
- }
- if (irq == -EPROBE_DEFER)
- return irq;
-
- if (irq < 0)
- irq = 0;
-
- client->irq = irq;
- }
-
- /*
- * An I2C ID table is not mandatory, if and only if, a suitable Device
- * Tree match table entry is supplied for the probing device.
- */
- if (!driver->id_table &&
- !i2c_of_match_device(dev->driver->of_match_table, client))
- return -ENODEV;
-
- if (client->flags & I2C_CLIENT_WAKE) {
- int wakeirq = -ENOENT;
-
- if (dev->of_node) {
- wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
- if (wakeirq == -EPROBE_DEFER)
- return wakeirq;
- }
-
- device_init_wakeup(&client->dev, true);
-
- if (wakeirq > 0 && wakeirq != client->irq)
- status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);
- else if (client->irq > 0)
- status = dev_pm_set_wake_irq(dev, client->irq);
- else
- status = 0;
-
- if (status)
- dev_warn(&client->dev, "failed to set up wakeup irq\n");
- }
-
- dev_dbg(dev, "probe\n");
-
- status = of_clk_set_defaults(dev->of_node, false);
- if (status < 0)
- goto err_clear_wakeup_irq;
-
- status = dev_pm_domain_attach(&client->dev, true);
- if (status == -EPROBE_DEFER)
- goto err_clear_wakeup_irq;
-
- /*
- * When there are no more users of probe(),
- * rename probe_new to probe.
- */
- if (driver->probe_new)
- status = driver->probe_new(client);
- else if (driver->probe)
- status = driver->probe(client,
- i2c_match_id(driver->id_table, client));
- else
- status = -EINVAL;
-
- if (status)
- goto err_detach_pm_domain;
-
- return 0;
-
-err_detach_pm_domain:
- dev_pm_domain_detach(&client->dev, true);
-err_clear_wakeup_irq:
- dev_pm_clear_wake_irq(&client->dev);
- device_init_wakeup(&client->dev, false);
- return status;
-}
-
-static int i2c_device_remove(struct device *dev)
-{
- struct i2c_client *client = i2c_verify_client(dev);
- struct i2c_driver *driver;
- int status = 0;
-
- if (!client || !dev->driver)
- return 0;
-
- driver = to_i2c_driver(dev->driver);
- if (driver->remove) {
- dev_dbg(dev, "remove\n");
- status = driver->remove(client);
- }
-
- dev_pm_domain_detach(&client->dev, true);
-
- dev_pm_clear_wake_irq(&client->dev);
- device_init_wakeup(&client->dev, false);
-
- return status;
-}
-
-static void i2c_device_shutdown(struct device *dev)
-{
- struct i2c_client *client = i2c_verify_client(dev);
- struct i2c_driver *driver;
-
- if (!client || !dev->driver)
- return;
- driver = to_i2c_driver(dev->driver);
- if (driver->shutdown)
- driver->shutdown(client);
-}
-
-static void i2c_client_dev_release(struct device *dev)
-{
- kfree(to_i2c_client(dev));
-}
-
-static ssize_t
-show_name(struct device *dev, struct device_attribute *attr, char *buf)
-{
- return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
- to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
-}
-static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
-
-static ssize_t
-show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
-{
- struct i2c_client *client = to_i2c_client(dev);
- int len;
-
- len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
- if (len != -ENODEV)
- return len;
-
- return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
-}
-static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
-
-static struct attribute *i2c_dev_attrs[] = {
- &dev_attr_name.attr,
- /* modalias helps coldplug: modprobe $(cat .../modalias) */
- &dev_attr_modalias.attr,
- NULL
-};
-ATTRIBUTE_GROUPS(i2c_dev);
-
-struct bus_type i2c_bus_type = {
- .name = "i2c",
- .match = i2c_device_match,
- .probe = i2c_device_probe,
- .remove = i2c_device_remove,
- .shutdown = i2c_device_shutdown,
-};
-EXPORT_SYMBOL_GPL(i2c_bus_type);
-
-struct device_type i2c_client_type = {
- .groups = i2c_dev_groups,
- .uevent = i2c_device_uevent,
- .release = i2c_client_dev_release,
-};
-EXPORT_SYMBOL_GPL(i2c_client_type);
-
-
-/**
- * i2c_verify_client - return parameter as i2c_client, or NULL
- * @dev: device, probably from some driver model iterator
- *
- * When traversing the driver model tree, perhaps using driver model
- * iterators like @device_for_each_child(), you can't assume very much
- * about the nodes you find. Use this function to avoid oopses caused
- * by wrongly treating some non-I2C device as an i2c_client.
- */
-struct i2c_client *i2c_verify_client(struct device *dev)
-{
- return (dev->type == &i2c_client_type)
- ? to_i2c_client(dev)
- : NULL;
-}
-EXPORT_SYMBOL(i2c_verify_client);
-
-
-/* Return a unique address which takes the flags of the client into account */
-static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)
-{
- unsigned short addr = client->addr;
-
- /* For some client flags, add an arbitrary offset to avoid collisions */
- if (client->flags & I2C_CLIENT_TEN)
- addr |= I2C_ADDR_OFFSET_TEN_BIT;
-
- if (client->flags & I2C_CLIENT_SLAVE)
- addr |= I2C_ADDR_OFFSET_SLAVE;
-
- return addr;
-}
-
-/* This is a permissive address validity check, I2C address map constraints
- * are purposely not enforced, except for the general call address. */
-static int i2c_check_addr_validity(unsigned addr, unsigned short flags)
-{
- if (flags & I2C_CLIENT_TEN) {
- /* 10-bit address, all values are valid */
- if (addr > 0x3ff)
- return -EINVAL;
- } else {
- /* 7-bit address, reject the general call address */
- if (addr == 0x00 || addr > 0x7f)
- return -EINVAL;
- }
- return 0;
-}
-
-/* And this is a strict address validity check, used when probing. If a
- * device uses a reserved address, then it shouldn't be probed. 7-bit
- * addressing is assumed, 10-bit address devices are rare and should be
- * explicitly enumerated. */
-static int i2c_check_7bit_addr_validity_strict(unsigned short addr)
-{
- /*
- * Reserved addresses per I2C specification:
- * 0x00 General call address / START byte
- * 0x01 CBUS address
- * 0x02 Reserved for different bus format
- * 0x03 Reserved for future purposes
- * 0x04-0x07 Hs-mode master code
- * 0x78-0x7b 10-bit slave addressing
- * 0x7c-0x7f Reserved for future purposes
- */
- if (addr < 0x08 || addr > 0x77)
- return -EINVAL;
- return 0;
-}
-
-static int __i2c_check_addr_busy(struct device *dev, void *addrp)
-{
- struct i2c_client *client = i2c_verify_client(dev);
- int addr = *(int *)addrp;
-
- if (client && i2c_encode_flags_to_addr(client) == addr)
- return -EBUSY;
- return 0;
-}
-
-/* walk up mux tree */
-static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
-{
- struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
- int result;
-
- result = device_for_each_child(&adapter->dev, &addr,
- __i2c_check_addr_busy);
-
- if (!result && parent)
- result = i2c_check_mux_parents(parent, addr);
-
- return result;
-}
-
-/* recurse down mux tree */
-static int i2c_check_mux_children(struct device *dev, void *addrp)
-{
- int result;
-
- if (dev->type == &i2c_adapter_type)
- result = device_for_each_child(dev, addrp,
- i2c_check_mux_children);
- else
- result = __i2c_check_addr_busy(dev, addrp);
-
- return result;
-}
-
-static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
-{
- struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
- int result = 0;
-
- if (parent)
- result = i2c_check_mux_parents(parent, addr);
-
- if (!result)
- result = device_for_each_child(&adapter->dev, &addr,
- i2c_check_mux_children);
-
- return result;
-}
-
-/**
- * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment
- * @adapter: Target I2C bus segment
- * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
- * locks only this branch in the adapter tree
- */
-static void i2c_adapter_lock_bus(struct i2c_adapter *adapter,
- unsigned int flags)
-{
- rt_mutex_lock(&adapter->bus_lock);
-}
-
-/**
- * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment
- * @adapter: Target I2C bus segment
- * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT
- * trylocks only this branch in the adapter tree
- */
-static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter,
- unsigned int flags)
-{
- return rt_mutex_trylock(&adapter->bus_lock);
-}
-
-/**
- * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment
- * @adapter: Target I2C bus segment
- * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
- * unlocks only this branch in the adapter tree
- */
-static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,
- unsigned int flags)
-{
- rt_mutex_unlock(&adapter->bus_lock);
-}
-
-static void i2c_dev_set_name(struct i2c_adapter *adap,
- struct i2c_client *client)
-{
- struct acpi_device *adev = ACPI_COMPANION(&client->dev);
-
- if (adev) {
- dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));
- return;
- }
-
- dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
- i2c_encode_flags_to_addr(client));
-}
-
-static int i2c_dev_irq_from_resources(const struct resource *resources,
- unsigned int num_resources)
-{
- struct irq_data *irqd;
- int i;
-
- for (i = 0; i < num_resources; i++) {
- const struct resource *r = &resources[i];
-
- if (resource_type(r) != IORESOURCE_IRQ)
- continue;
-
- if (r->flags & IORESOURCE_BITS) {
- irqd = irq_get_irq_data(r->start);
- if (!irqd)
- break;
-
- irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
- }
-
- return r->start;
- }
-
- return 0;
-}
-
-/**
- * i2c_new_device - instantiate an i2c device
- * @adap: the adapter managing the device
- * @info: describes one I2C device; bus_num is ignored
- * Context: can sleep
- *
- * Create an i2c device. Binding is handled through driver model
- * probe()/remove() methods. A driver may be bound to this device when we
- * return from this function, or any later moment (e.g. maybe hotplugging will
- * load the driver module). This call is not appropriate for use by mainboard
- * initialization logic, which usually runs during an arch_initcall() long
- * before any i2c_adapter could exist.
- *
- * This returns the new i2c client, which may be saved for later use with
- * i2c_unregister_device(); or NULL to indicate an error.
- */
-struct i2c_client *
-i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
-{
- struct i2c_client *client;
- int status;
-
- client = kzalloc(sizeof *client, GFP_KERNEL);
- if (!client)
- return NULL;
-
- client->adapter = adap;
-
- client->dev.platform_data = info->platform_data;
-
- if (info->archdata)
- client->dev.archdata = *info->archdata;
-
- client->flags = info->flags;
- client->addr = info->addr;
-
- client->irq = info->irq;
- if (!client->irq)
- client->irq = i2c_dev_irq_from_resources(info->resources,
- info->num_resources);
-
- strlcpy(client->name, info->type, sizeof(client->name));
-
- status = i2c_check_addr_validity(client->addr, client->flags);
- if (status) {
- dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n",
- client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr);
- goto out_err_silent;
- }
-
- /* Check for address business */
- status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
- if (status)
- goto out_err;
-
- client->dev.parent = &client->adapter->dev;
- client->dev.bus = &i2c_bus_type;
- client->dev.type = &i2c_client_type;
- client->dev.of_node = info->of_node;
- client->dev.fwnode = info->fwnode;
-
- i2c_dev_set_name(adap, client);
-
- if (info->properties) {
- status = device_add_properties(&client->dev, info->properties);
- if (status) {
- dev_err(&adap->dev,
- "Failed to add properties to client %s: %d\n",
- client->name, status);
- goto out_err;
- }
- }
-
- status = device_register(&client->dev);
- if (status)
- goto out_free_props;
-
- dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
- client->name, dev_name(&client->dev));
-
- return client;
-
-out_free_props:
- if (info->properties)
- device_remove_properties(&client->dev);
-out_err:
- dev_err(&adap->dev,
- "Failed to register i2c client %s at 0x%02x (%d)\n",
- client->name, client->addr, status);
-out_err_silent:
- kfree(client);
- return NULL;
-}
-EXPORT_SYMBOL_GPL(i2c_new_device);
-
-
-/**
- * i2c_unregister_device - reverse effect of i2c_new_device()
- * @client: value returned from i2c_new_device()
- * Context: can sleep
- */
-void i2c_unregister_device(struct i2c_client *client)
-{
- if (client->dev.of_node)
- of_node_clear_flag(client->dev.of_node, OF_POPULATED);
- if (ACPI_COMPANION(&client->dev))
- acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));
- device_unregister(&client->dev);
-}
-EXPORT_SYMBOL_GPL(i2c_unregister_device);
-
-
-static const struct i2c_device_id dummy_id[] = {
- { "dummy", 0 },
- { },
-};
-
-static int dummy_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
-{
- return 0;
-}
-
-static int dummy_remove(struct i2c_client *client)
-{
- return 0;
-}
-
-static struct i2c_driver dummy_driver = {
- .driver.name = "dummy",
- .probe = dummy_probe,
- .remove = dummy_remove,
- .id_table = dummy_id,
-};
-
-/**
- * i2c_new_dummy - return a new i2c device bound to a dummy driver
- * @adapter: the adapter managing the device
- * @address: seven bit address to be used
- * Context: can sleep
- *
- * This returns an I2C client bound to the "dummy" driver, intended for use
- * with devices that consume multiple addresses. Examples of such chips
- * include various EEPROMS (like 24c04 and 24c08 models).
- *
- * These dummy devices have two main uses. First, most I2C and SMBus calls
- * except i2c_transfer() need a client handle; the dummy will be that handle.
- * And second, this prevents the specified address from being bound to a
- * different driver.
- *
- * This returns the new i2c client, which should be saved for later use with
- * i2c_unregister_device(); or NULL to indicate an error.
- */
-struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
-{
- struct i2c_board_info info = {
- I2C_BOARD_INFO("dummy", address),
- };
-
- return i2c_new_device(adapter, &info);
-}
-EXPORT_SYMBOL_GPL(i2c_new_dummy);
-
-/**
- * i2c_new_secondary_device - Helper to get the instantiated secondary address
- * and create the associated device
- * @client: Handle to the primary client
- * @name: Handle to specify which secondary address to get
- * @default_addr: Used as a fallback if no secondary address was specified
- * Context: can sleep
- *
- * I2C clients can be composed of multiple I2C slaves bound together in a single
- * component. The I2C client driver then binds to the master I2C slave and needs
- * to create I2C dummy clients to communicate with all the other slaves.
- *
- * This function creates and returns an I2C dummy client whose I2C address is
- * retrieved from the platform firmware based on the given slave name. If no
- * address is specified by the firmware default_addr is used.
- *
- * On DT-based platforms the address is retrieved from the "reg" property entry
- * cell whose "reg-names" value matches the slave name.
- *
- * This returns the new i2c client, which should be saved for later use with
- * i2c_unregister_device(); or NULL to indicate an error.
- */
-struct i2c_client *i2c_new_secondary_device(struct i2c_client *client,
- const char *name,
- u16 default_addr)
-{
- struct device_node *np = client->dev.of_node;
- u32 addr = default_addr;
- int i;
-
- if (np) {
- i = of_property_match_string(np, "reg-names", name);
- if (i >= 0)
- of_property_read_u32_index(np, "reg", i, &addr);
- }
-
- dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
- return i2c_new_dummy(client->adapter, addr);
-}
-EXPORT_SYMBOL_GPL(i2c_new_secondary_device);
-
-/* ------------------------------------------------------------------------- */
-
-/* I2C bus adapters -- one roots each I2C or SMBUS segment */
-
-static void i2c_adapter_dev_release(struct device *dev)
-{
- struct i2c_adapter *adap = to_i2c_adapter(dev);
- complete(&adap->dev_released);
-}
-
-unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
-{
- unsigned int depth = 0;
-
- while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
- depth++;
-
- WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES,
- "adapter depth exceeds lockdep subclass limit\n");
-
- return depth;
-}
-EXPORT_SYMBOL_GPL(i2c_adapter_depth);
-
-/*
- * Let users instantiate I2C devices through sysfs. This can be used when
- * platform initialization code doesn't contain the proper data for
- * whatever reason. Also useful for drivers that do device detection and
- * detection fails, either because the device uses an unexpected address,
- * or this is a compatible device with different ID register values.
- *
- * Parameter checking may look overzealous, but we really don't want
- * the user to provide incorrect parameters.
- */
-static ssize_t
-i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct i2c_adapter *adap = to_i2c_adapter(dev);
- struct i2c_board_info info;
- struct i2c_client *client;
- char *blank, end;
- int res;
-
- memset(&info, 0, sizeof(struct i2c_board_info));
-
- blank = strchr(buf, ' ');
- if (!blank) {
- dev_err(dev, "%s: Missing parameters\n", "new_device");
- return -EINVAL;
- }
- if (blank - buf > I2C_NAME_SIZE - 1) {
- dev_err(dev, "%s: Invalid device name\n", "new_device");
- return -EINVAL;
- }
- memcpy(info.type, buf, blank - buf);
-
- /* Parse remaining parameters, reject extra parameters */
- res = sscanf(++blank, "%hi%c", &info.addr, &end);
- if (res < 1) {
- dev_err(dev, "%s: Can't parse I2C address\n", "new_device");
- return -EINVAL;
- }
- if (res > 1 && end != '\n') {
- dev_err(dev, "%s: Extra parameters\n", "new_device");
- return -EINVAL;
- }
-
- if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) {
- info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT;
- info.flags |= I2C_CLIENT_TEN;
- }
-
- if (info.addr & I2C_ADDR_OFFSET_SLAVE) {
- info.addr &= ~I2C_ADDR_OFFSET_SLAVE;
- info.flags |= I2C_CLIENT_SLAVE;
- }
-
- client = i2c_new_device(adap, &info);
- if (!client)
- return -EINVAL;
-
- /* Keep track of the added device */
- mutex_lock(&adap->userspace_clients_lock);
- list_add_tail(&client->detected, &adap->userspace_clients);
- mutex_unlock(&adap->userspace_clients_lock);
- dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
- info.type, info.addr);
-
- return count;
-}
-static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device);
-
-/*
- * And of course let the users delete the devices they instantiated, if
- * they got it wrong. This interface can only be used to delete devices
- * instantiated by i2c_sysfs_new_device above. This guarantees that we
- * don't delete devices to which some kernel code still has references.
- *
- * Parameter checking may look overzealous, but we really don't want
- * the user to delete the wrong device.
- */
-static ssize_t
-i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct i2c_adapter *adap = to_i2c_adapter(dev);
- struct i2c_client *client, *next;
- unsigned short addr;
- char end;
- int res;
-
- /* Parse parameters, reject extra parameters */
- res = sscanf(buf, "%hi%c", &addr, &end);
- if (res < 1) {
- dev_err(dev, "%s: Can't parse I2C address\n", "delete_device");
- return -EINVAL;
- }
- if (res > 1 && end != '\n') {
- dev_err(dev, "%s: Extra parameters\n", "delete_device");
- return -EINVAL;
- }
-
- /* Make sure the device was added through sysfs */
- res = -ENOENT;
- mutex_lock_nested(&adap->userspace_clients_lock,
- i2c_adapter_depth(adap));
- list_for_each_entry_safe(client, next, &adap->userspace_clients,
- detected) {
- if (i2c_encode_flags_to_addr(client) == addr) {
- dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
- "delete_device", client->name, client->addr);
-
- list_del(&client->detected);
- i2c_unregister_device(client);
- res = count;
- break;
- }
- }
- mutex_unlock(&adap->userspace_clients_lock);
-
- if (res < 0)
- dev_err(dev, "%s: Can't find device in list\n",
- "delete_device");
- return res;
-}
-static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL,
- i2c_sysfs_delete_device);
-
-static struct attribute *i2c_adapter_attrs[] = {
- &dev_attr_name.attr,
- &dev_attr_new_device.attr,
- &dev_attr_delete_device.attr,
- NULL
-};
-ATTRIBUTE_GROUPS(i2c_adapter);
-
-struct device_type i2c_adapter_type = {
- .groups = i2c_adapter_groups,
- .release = i2c_adapter_dev_release,
-};
-EXPORT_SYMBOL_GPL(i2c_adapter_type);
-
-/**
- * i2c_verify_adapter - return parameter as i2c_adapter or NULL
- * @dev: device, probably from some driver model iterator
- *
- * When traversing the driver model tree, perhaps using driver model
- * iterators like @device_for_each_child(), you can't assume very much
- * about the nodes you find. Use this function to avoid oopses caused
- * by wrongly treating some non-I2C device as an i2c_adapter.
- */
-struct i2c_adapter *i2c_verify_adapter(struct device *dev)
-{
- return (dev->type == &i2c_adapter_type)
- ? to_i2c_adapter(dev)
- : NULL;
-}
-EXPORT_SYMBOL(i2c_verify_adapter);
-
-#ifdef CONFIG_I2C_COMPAT
-static struct class_compat *i2c_adapter_compat_class;
-#endif
-
-static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
-{
- struct i2c_devinfo *devinfo;
-
- down_read(&__i2c_board_lock);
- list_for_each_entry(devinfo, &__i2c_board_list, list) {
- if (devinfo->busnum == adapter->nr
- && !i2c_new_device(adapter,
- &devinfo->board_info))
- dev_err(&adapter->dev,
- "Can't create device at 0x%02x\n",
- devinfo->board_info.addr);
- }
- up_read(&__i2c_board_lock);
-}
-
-/* OF support code */
-
-#if IS_ENABLED(CONFIG_OF)
-static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
- struct device_node *node)
-{
- struct i2c_client *result;
- struct i2c_board_info info = {};
- struct dev_archdata dev_ad = {};
- const __be32 *addr_be;
- u32 addr;
- int len;
-
- dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name);
-
- if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) {
- dev_err(&adap->dev, "of_i2c: modalias failure on %s\n",
- node->full_name);
- return ERR_PTR(-EINVAL);
- }
-
- addr_be = of_get_property(node, "reg", &len);
- if (!addr_be || (len < sizeof(*addr_be))) {
- dev_err(&adap->dev, "of_i2c: invalid reg on %s\n",
- node->full_name);
- return ERR_PTR(-EINVAL);
- }
-
- addr = be32_to_cpup(addr_be);
- if (addr & I2C_TEN_BIT_ADDRESS) {
- addr &= ~I2C_TEN_BIT_ADDRESS;
- info.flags |= I2C_CLIENT_TEN;
- }
-
- if (addr & I2C_OWN_SLAVE_ADDRESS) {
- addr &= ~I2C_OWN_SLAVE_ADDRESS;
- info.flags |= I2C_CLIENT_SLAVE;
- }
-
- if (i2c_check_addr_validity(addr, info.flags)) {
- dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n",
- addr, node->full_name);
- return ERR_PTR(-EINVAL);
- }
-
- info.addr = addr;
- info.of_node = of_node_get(node);
- info.archdata = &dev_ad;
-
- if (of_property_read_bool(node, "host-notify"))
- info.flags |= I2C_CLIENT_HOST_NOTIFY;
-
- if (of_get_property(node, "wakeup-source", NULL))
- info.flags |= I2C_CLIENT_WAKE;
-
- result = i2c_new_device(adap, &info);
- if (result == NULL) {
- dev_err(&adap->dev, "of_i2c: Failure registering %s\n",
- node->full_name);
- of_node_put(node);
- return ERR_PTR(-EINVAL);
- }
- return result;
-}
-
-static void of_i2c_register_devices(struct i2c_adapter *adap)
-{
- struct device_node *bus, *node;
- struct i2c_client *client;
-
- /* Only register child devices if the adapter has a node pointer set */
- if (!adap->dev.of_node)
- return;
-
- dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");
-
- bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus");
- if (!bus)
- bus = of_node_get(adap->dev.of_node);
-
- for_each_available_child_of_node(bus, node) {
- if (of_node_test_and_set_flag(node, OF_POPULATED))
- continue;
-
- client = of_i2c_register_device(adap, node);
- if (IS_ERR(client)) {
- dev_warn(&adap->dev,
- "Failed to create I2C device for %s\n",
- node->full_name);
- of_node_clear_flag(node, OF_POPULATED);
- }
- }
-
- of_node_put(bus);
-}
-
-static int of_dev_node_match(struct device *dev, void *data)
-{
- return dev->of_node == data;
-}
-
-/* must call put_device() when done with returned i2c_client device */
-struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
-{
- struct device *dev;
- struct i2c_client *client;
-
- dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match);
- if (!dev)
- return NULL;
-
- client = i2c_verify_client(dev);
- if (!client)
- put_device(dev);
-
- return client;
-}
-EXPORT_SYMBOL(of_find_i2c_device_by_node);
-
-/* must call put_device() when done with returned i2c_adapter device */
-struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
-{
- struct device *dev;
- struct i2c_adapter *adapter;
-
- dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match);
- if (!dev)
- return NULL;
-
- adapter = i2c_verify_adapter(dev);
- if (!adapter)
- put_device(dev);
-
- return adapter;
-}
-EXPORT_SYMBOL(of_find_i2c_adapter_by_node);
-
-/* must call i2c_put_adapter() when done with returned i2c_adapter device */
-struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
-{
- struct i2c_adapter *adapter;
-
- adapter = of_find_i2c_adapter_by_node(node);
- if (!adapter)
- return NULL;
-
- if (!try_module_get(adapter->owner)) {
- put_device(&adapter->dev);
- adapter = NULL;
- }
-
- return adapter;
-}
-EXPORT_SYMBOL(of_get_i2c_adapter_by_node);
-
-static const struct of_device_id*
-i2c_of_match_device_sysfs(const struct of_device_id *matches,
- struct i2c_client *client)
-{
- const char *name;
-
- for (; matches->compatible[0]; matches++) {
- /*
- * Adding devices through the i2c sysfs interface provides us
- * a string to match which may be compatible with the device
- * tree compatible strings, however with no actual of_node the
- * of_match_device() will not match
- */
- if (sysfs_streq(client->name, matches->compatible))
- return matches;
-
- name = strchr(matches->compatible, ',');
- if (!name)
- name = matches->compatible;
- else
- name++;
-
- if (sysfs_streq(client->name, name))
- return matches;
- }
-
- return NULL;
-}
-
-const struct of_device_id
-*i2c_of_match_device(const struct of_device_id *matches,
- struct i2c_client *client)
-{
- const struct of_device_id *match;
-
- if (!(client && matches))
- return NULL;
-
- match = of_match_device(matches, &client->dev);
- if (match)
- return match;
-
- return i2c_of_match_device_sysfs(matches, client);
-}
-EXPORT_SYMBOL_GPL(i2c_of_match_device);
-#else
-static void of_i2c_register_devices(struct i2c_adapter *adap) { }
-#endif /* CONFIG_OF */
-
-static int i2c_do_add_adapter(struct i2c_driver *driver,
- struct i2c_adapter *adap)
-{
- /* Detect supported devices on that bus, and instantiate them */
- i2c_detect(adap, driver);
-
- /* Let legacy drivers scan this bus for matching devices */
- if (driver->attach_adapter) {
- dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n",
- driver->driver.name);
- dev_warn(&adap->dev,
- "Please use another way to instantiate your i2c_client\n");
- /* We ignore the return code; if it fails, too bad */
- driver->attach_adapter(adap);
- }
- return 0;
-}
-
-static int __process_new_adapter(struct device_driver *d, void *data)
-{
- return i2c_do_add_adapter(to_i2c_driver(d), data);
-}
-
-static const struct i2c_lock_operations i2c_adapter_lock_ops = {
- .lock_bus = i2c_adapter_lock_bus,
- .trylock_bus = i2c_adapter_trylock_bus,
- .unlock_bus = i2c_adapter_unlock_bus,
-};
-
-static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap)
-{
- struct irq_domain *domain = adap->host_notify_domain;
- irq_hw_number_t hwirq;
-
- if (!domain)
- return;
-
- for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++)
- irq_dispose_mapping(irq_find_mapping(domain, hwirq));
-
- irq_domain_remove(domain);
- adap->host_notify_domain = NULL;
-}
-
-static int i2c_host_notify_irq_map(struct irq_domain *h,
- unsigned int virq,
- irq_hw_number_t hw_irq_num)
-{
- irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
-
- return 0;
-}
-
-static const struct irq_domain_ops i2c_host_notify_irq_ops = {
- .map = i2c_host_notify_irq_map,
-};
-
-static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap)
-{
- struct irq_domain *domain;
-
- if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY))
- return 0;
-
- domain = irq_domain_create_linear(adap->dev.fwnode,
- I2C_ADDR_7BITS_COUNT,
- &i2c_host_notify_irq_ops, adap);
- if (!domain)
- return -ENOMEM;
-
- adap->host_notify_domain = domain;
-
- return 0;
-}
-
-/**
- * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct
- * I2C client.
- * @adap: the adapter
- * @addr: the I2C address of the notifying device
- * Context: can't sleep
- *
- * Helper function to be called from an I2C bus driver's interrupt
- * handler. It will schedule the Host Notify IRQ.
- */
-int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)
-{
- int irq;
-
- if (!adap)
- return -EINVAL;
-
- irq = irq_find_mapping(adap->host_notify_domain, addr);
- if (irq <= 0)
- return -ENXIO;
-
- generic_handle_irq(irq);
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify);
-
-static int i2c_register_adapter(struct i2c_adapter *adap)
-{
- int res = -EINVAL;
-
- /* Can't register until after driver model init */
- if (WARN_ON(!is_registered)) {
- res = -EAGAIN;
- goto out_list;
- }
-
- /* Sanity checks */
- if (WARN(!adap->name[0], "i2c adapter has no name"))
- goto out_list;
-
- if (!adap->algo) {
- pr_err("adapter '%s': no algo supplied!\n", adap->name);
- goto out_list;
- }
-
- if (!adap->lock_ops)
- adap->lock_ops = &i2c_adapter_lock_ops;
-
- rt_mutex_init(&adap->bus_lock);
- rt_mutex_init(&adap->mux_lock);
- mutex_init(&adap->userspace_clients_lock);
- INIT_LIST_HEAD(&adap->userspace_clients);
-
- /* Set default timeout to 1 second if not already set */
- if (adap->timeout == 0)
- adap->timeout = HZ;
-
- /* register soft irqs for Host Notify */
- res = i2c_setup_host_notify_irq_domain(adap);
- if (res) {
- pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n",
- adap->name, res);
- goto out_list;
- }
-
- dev_set_name(&adap->dev, "i2c-%d", adap->nr);
- adap->dev.bus = &i2c_bus_type;
- adap->dev.type = &i2c_adapter_type;
- res = device_register(&adap->dev);
- if (res) {
- pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
- goto out_list;
- }
-
- dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
-
- pm_runtime_no_callbacks(&adap->dev);
- pm_suspend_ignore_children(&adap->dev, true);
- pm_runtime_enable(&adap->dev);
-
-#ifdef CONFIG_I2C_COMPAT
- res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev,
- adap->dev.parent);
- if (res)
- dev_warn(&adap->dev,
- "Failed to create compatibility class link\n");
-#endif
-
- i2c_init_recovery(adap);
-
- /* create pre-declared device nodes */
- of_i2c_register_devices(adap);
- i2c_acpi_register_devices(adap);
- i2c_acpi_install_space_handler(adap);
-
- if (adap->nr < __i2c_first_dynamic_bus_num)
- i2c_scan_static_board_info(adap);
-
- /* Notify drivers */
- mutex_lock(&core_lock);
- bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter);
- mutex_unlock(&core_lock);
-
- return 0;
-
-out_list:
- mutex_lock(&core_lock);
- idr_remove(&i2c_adapter_idr, adap->nr);
- mutex_unlock(&core_lock);
- return res;
-}
-
-/**
- * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1
- * @adap: the adapter to register (with adap->nr initialized)
- * Context: can sleep
- *
- * See i2c_add_numbered_adapter() for details.
- */
-static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
-{
- int id;
-
- mutex_lock(&core_lock);
- id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL);
- mutex_unlock(&core_lock);
- if (WARN(id < 0, "couldn't get idr"))
- return id == -ENOSPC ? -EBUSY : id;
-
- return i2c_register_adapter(adap);
-}
-
-/**
- * i2c_add_adapter - declare i2c adapter, use dynamic bus number
- * @adapter: the adapter to add
- * Context: can sleep
- *
- * This routine is used to declare an I2C adapter when its bus number
- * doesn't matter or when its bus number is specified by an dt alias.
- * Examples of bases when the bus number doesn't matter: I2C adapters
- * dynamically added by USB links or PCI plugin cards.
- *
- * When this returns zero, a new bus number was allocated and stored
- * in adap->nr, and the specified adapter became available for clients.
- * Otherwise, a negative errno value is returned.
- */
-int i2c_add_adapter(struct i2c_adapter *adapter)
-{
- struct device *dev = &adapter->dev;
- int id;
-
- if (dev->of_node) {
- id = of_alias_get_id(dev->of_node, "i2c");
- if (id >= 0) {
- adapter->nr = id;
- return __i2c_add_numbered_adapter(adapter);
- }
- }
-
- mutex_lock(&core_lock);
- id = idr_alloc(&i2c_adapter_idr, adapter,
- __i2c_first_dynamic_bus_num, 0, GFP_KERNEL);
- mutex_unlock(&core_lock);
- if (WARN(id < 0, "couldn't get idr"))
- return id;
-
- adapter->nr = id;
-
- return i2c_register_adapter(adapter);
-}
-EXPORT_SYMBOL(i2c_add_adapter);
-
-/**
- * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
- * @adap: the adapter to register (with adap->nr initialized)
- * Context: can sleep
- *
- * This routine is used to declare an I2C adapter when its bus number
- * matters. For example, use it for I2C adapters from system-on-chip CPUs,
- * or otherwise built in to the system's mainboard, and where i2c_board_info
- * is used to properly configure I2C devices.
- *
- * If the requested bus number is set to -1, then this function will behave
- * identically to i2c_add_adapter, and will dynamically assign a bus number.
- *
- * If no devices have pre-been declared for this bus, then be sure to
- * register the adapter before any dynamically allocated ones. Otherwise
- * the required bus ID may not be available.
- *
- * When this returns zero, the specified adapter became available for
- * clients using the bus number provided in adap->nr. Also, the table
- * of I2C devices pre-declared using i2c_register_board_info() is scanned,
- * and the appropriate driver model device nodes are created. Otherwise, a
- * negative errno value is returned.
- */
-int i2c_add_numbered_adapter(struct i2c_adapter *adap)
-{
- if (adap->nr == -1) /* -1 means dynamically assign bus id */
- return i2c_add_adapter(adap);
-
- return __i2c_add_numbered_adapter(adap);
-}
-EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
-
-static void i2c_do_del_adapter(struct i2c_driver *driver,
- struct i2c_adapter *adapter)
-{
- struct i2c_client *client, *_n;
-
- /* Remove the devices we created ourselves as the result of hardware
- * probing (using a driver's detect method) */
- list_for_each_entry_safe(client, _n, &driver->clients, detected) {
- if (client->adapter == adapter) {
- dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
- client->name, client->addr);
- list_del(&client->detected);
- i2c_unregister_device(client);
- }
- }
-}
-
-static int __unregister_client(struct device *dev, void *dummy)
-{
- struct i2c_client *client = i2c_verify_client(dev);
- if (client && strcmp(client->name, "dummy"))
- i2c_unregister_device(client);
- return 0;
-}
-
-static int __unregister_dummy(struct device *dev, void *dummy)
-{
- struct i2c_client *client = i2c_verify_client(dev);
- if (client)
- i2c_unregister_device(client);
- return 0;
-}
-
-static int __process_removed_adapter(struct device_driver *d, void *data)
-{
- i2c_do_del_adapter(to_i2c_driver(d), data);
- return 0;
-}
-
-/**
- * i2c_del_adapter - unregister I2C adapter
- * @adap: the adapter being unregistered
- * Context: can sleep
- *
- * This unregisters an I2C adapter which was previously registered
- * by @i2c_add_adapter or @i2c_add_numbered_adapter.
- */
-void i2c_del_adapter(struct i2c_adapter *adap)
-{
- struct i2c_adapter *found;
- struct i2c_client *client, *next;
-
- /* First make sure that this adapter was ever added */
- mutex_lock(&core_lock);
- found = idr_find(&i2c_adapter_idr, adap->nr);
- mutex_unlock(&core_lock);
- if (found != adap) {
- pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);
- return;
- }
-
- i2c_acpi_remove_space_handler(adap);
- /* Tell drivers about this removal */
- mutex_lock(&core_lock);
- bus_for_each_drv(&i2c_bus_type, NULL, adap,
- __process_removed_adapter);
- mutex_unlock(&core_lock);
-
- /* Remove devices instantiated from sysfs */
- mutex_lock_nested(&adap->userspace_clients_lock,
- i2c_adapter_depth(adap));
- list_for_each_entry_safe(client, next, &adap->userspace_clients,
- detected) {
- dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
- client->addr);
- list_del(&client->detected);
- i2c_unregister_device(client);
- }
- mutex_unlock(&adap->userspace_clients_lock);
-
- /* Detach any active clients. This can't fail, thus we do not
- * check the returned value. This is a two-pass process, because
- * we can't remove the dummy devices during the first pass: they
- * could have been instantiated by real devices wishing to clean
- * them up properly, so we give them a chance to do that first. */
- device_for_each_child(&adap->dev, NULL, __unregister_client);
- device_for_each_child(&adap->dev, NULL, __unregister_dummy);
-
-#ifdef CONFIG_I2C_COMPAT
- class_compat_remove_link(i2c_adapter_compat_class, &adap->dev,
- adap->dev.parent);
-#endif
-
- /* device name is gone after device_unregister */
- dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
-
- pm_runtime_disable(&adap->dev);
-
- i2c_host_notify_irq_teardown(adap);
-
- /* wait until all references to the device are gone
- *
- * FIXME: This is old code and should ideally be replaced by an
- * alternative which results in decoupling the lifetime of the struct
- * device from the i2c_adapter, like spi or netdev do. Any solution
- * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled!
- */
- init_completion(&adap->dev_released);
- device_unregister(&adap->dev);
- wait_for_completion(&adap->dev_released);
-
- /* free bus id */
- mutex_lock(&core_lock);
- idr_remove(&i2c_adapter_idr, adap->nr);
- mutex_unlock(&core_lock);
-
- /* Clear the device structure in case this adapter is ever going to be
- added again */
- memset(&adap->dev, 0, sizeof(adap->dev));
-}
-EXPORT_SYMBOL(i2c_del_adapter);
-
-/**
- * i2c_parse_fw_timings - get I2C related timing parameters from firmware
- * @dev: The device to scan for I2C timing properties
- * @t: the i2c_timings struct to be filled with values
- * @use_defaults: bool to use sane defaults derived from the I2C specification
- * when properties are not found, otherwise use 0
- *
- * Scan the device for the generic I2C properties describing timing parameters
- * for the signal and fill the given struct with the results. If a property was
- * not found and use_defaults was true, then maximum timings are assumed which
- * are derived from the I2C specification. If use_defaults is not used, the
- * results will be 0, so drivers can apply their own defaults later. The latter
- * is mainly intended for avoiding regressions of existing drivers which want
- * to switch to this function. New drivers almost always should use the defaults.
- */
-
-void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults)
-{
- int ret;
-
- memset(t, 0, sizeof(*t));
-
- ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz);
- if (ret && use_defaults)
- t->bus_freq_hz = 100000;
-
- ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns);
- if (ret && use_defaults) {
- if (t->bus_freq_hz <= 100000)
- t->scl_rise_ns = 1000;
- else if (t->bus_freq_hz <= 400000)
- t->scl_rise_ns = 300;
- else
- t->scl_rise_ns = 120;
- }
-
- ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns);
- if (ret && use_defaults) {
- if (t->bus_freq_hz <= 400000)
- t->scl_fall_ns = 300;
- else
- t->scl_fall_ns = 120;
- }
-
- device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns);
-
- ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns);
- if (ret && use_defaults)
- t->sda_fall_ns = t->scl_fall_ns;
-}
-EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);
-
-/* ------------------------------------------------------------------------- */
-
-int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *))
-{
- int res;
-
- mutex_lock(&core_lock);
- res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn);
- mutex_unlock(&core_lock);
-
- return res;
-}
-EXPORT_SYMBOL_GPL(i2c_for_each_dev);
-
-static int __process_new_driver(struct device *dev, void *data)
-{
- if (dev->type != &i2c_adapter_type)
- return 0;
- return i2c_do_add_adapter(data, to_i2c_adapter(dev));
-}
-
-/*
- * An i2c_driver is used with one or more i2c_client (device) nodes to access
- * i2c slave chips, on a bus instance associated with some i2c_adapter.
- */
-
-int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
-{
- int res;
-
- /* Can't register until after driver model init */
- if (WARN_ON(!is_registered))
- return -EAGAIN;
-
- /* add the driver to the list of i2c drivers in the driver core */
- driver->driver.owner = owner;
- driver->driver.bus = &i2c_bus_type;
- INIT_LIST_HEAD(&driver->clients);
-
- /* When registration returns, the driver core
- * will have called probe() for all matching-but-unbound devices.
- */
- res = driver_register(&driver->driver);
- if (res)
- return res;
-
- pr_debug("driver [%s] registered\n", driver->driver.name);
-
- /* Walk the adapters that are already present */
- i2c_for_each_dev(driver, __process_new_driver);
-
- return 0;
-}
-EXPORT_SYMBOL(i2c_register_driver);
-
-static int __process_removed_driver(struct device *dev, void *data)
-{
- if (dev->type == &i2c_adapter_type)
- i2c_do_del_adapter(data, to_i2c_adapter(dev));
- return 0;
-}
-
-/**
- * i2c_del_driver - unregister I2C driver
- * @driver: the driver being unregistered
- * Context: can sleep
- */
-void i2c_del_driver(struct i2c_driver *driver)
-{
- i2c_for_each_dev(driver, __process_removed_driver);
-
- driver_unregister(&driver->driver);
- pr_debug("driver [%s] unregistered\n", driver->driver.name);
-}
-EXPORT_SYMBOL(i2c_del_driver);
-
-/* ------------------------------------------------------------------------- */
-
-/**
- * i2c_use_client - increments the reference count of the i2c client structure
- * @client: the client being referenced
- *
- * Each live reference to a client should be refcounted. The driver model does
- * that automatically as part of driver binding, so that most drivers don't
- * need to do this explicitly: they hold a reference until they're unbound
- * from the device.
- *
- * A pointer to the client with the incremented reference counter is returned.
- */
-struct i2c_client *i2c_use_client(struct i2c_client *client)
-{
- if (client && get_device(&client->dev))
- return client;
- return NULL;
-}
-EXPORT_SYMBOL(i2c_use_client);
-
-/**
- * i2c_release_client - release a use of the i2c client structure
- * @client: the client being no longer referenced
- *
- * Must be called when a user of a client is finished with it.
- */
-void i2c_release_client(struct i2c_client *client)
-{
- if (client)
- put_device(&client->dev);
-}
-EXPORT_SYMBOL(i2c_release_client);
-
-struct i2c_cmd_arg {
- unsigned cmd;
- void *arg;
-};
-
-static int i2c_cmd(struct device *dev, void *_arg)
-{
- struct i2c_client *client = i2c_verify_client(dev);
- struct i2c_cmd_arg *arg = _arg;
- struct i2c_driver *driver;
-
- if (!client || !client->dev.driver)
- return 0;
-
- driver = to_i2c_driver(client->dev.driver);
- if (driver->command)
- driver->command(client, arg->cmd, arg->arg);
- return 0;
-}
-
-void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
-{
- struct i2c_cmd_arg cmd_arg;
-
- cmd_arg.cmd = cmd;
- cmd_arg.arg = arg;
- device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
-}
-EXPORT_SYMBOL(i2c_clients_command);
-
-#if IS_ENABLED(CONFIG_OF_DYNAMIC)
-static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
- void *arg)
-{
- struct of_reconfig_data *rd = arg;
- struct i2c_adapter *adap;
- struct i2c_client *client;
-
- switch (of_reconfig_get_state_change(action, rd)) {
- case OF_RECONFIG_CHANGE_ADD:
- adap = of_find_i2c_adapter_by_node(rd->dn->parent);
- if (adap == NULL)
- return NOTIFY_OK; /* not for us */
-
- if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
- put_device(&adap->dev);
- return NOTIFY_OK;
- }
-
- client = of_i2c_register_device(adap, rd->dn);
- put_device(&adap->dev);
-
- if (IS_ERR(client)) {
- dev_err(&adap->dev, "failed to create client for '%s'\n",
- rd->dn->full_name);
- of_node_clear_flag(rd->dn, OF_POPULATED);
- return notifier_from_errno(PTR_ERR(client));
- }
- break;
- case OF_RECONFIG_CHANGE_REMOVE:
- /* already depopulated? */
- if (!of_node_check_flag(rd->dn, OF_POPULATED))
- return NOTIFY_OK;
-
- /* find our device by node */
- client = of_find_i2c_device_by_node(rd->dn);
- if (client == NULL)
- return NOTIFY_OK; /* no? not meant for us */
-
- /* unregister takes one ref away */
- i2c_unregister_device(client);
-
- /* and put the reference of the find */
- put_device(&client->dev);
- break;
- }
-
- return NOTIFY_OK;
-}
-static struct notifier_block i2c_of_notifier = {
- .notifier_call = of_i2c_notify,
-};
-#else
-extern struct notifier_block i2c_of_notifier;
-#endif /* CONFIG_OF_DYNAMIC */
-
-static int __init i2c_init(void)
-{
- int retval;
-
- retval = of_alias_get_highest_id("i2c");
-
- down_write(&__i2c_board_lock);
- if (retval >= __i2c_first_dynamic_bus_num)
- __i2c_first_dynamic_bus_num = retval + 1;
- up_write(&__i2c_board_lock);
-
- retval = bus_register(&i2c_bus_type);
- if (retval)
- return retval;
-
- is_registered = true;
-
-#ifdef CONFIG_I2C_COMPAT
- i2c_adapter_compat_class = class_compat_register("i2c-adapter");
- if (!i2c_adapter_compat_class) {
- retval = -ENOMEM;
- goto bus_err;
- }
-#endif
- retval = i2c_add_driver(&dummy_driver);
- if (retval)
- goto class_err;
-
- if (IS_ENABLED(CONFIG_OF_DYNAMIC))
- WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier));
- if (IS_ENABLED(CONFIG_ACPI))
- WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier));
-
- return 0;
-
-class_err:
-#ifdef CONFIG_I2C_COMPAT
- class_compat_unregister(i2c_adapter_compat_class);
-bus_err:
-#endif
- is_registered = false;
- bus_unregister(&i2c_bus_type);
- return retval;
-}
-
-static void __exit i2c_exit(void)
-{
- if (IS_ENABLED(CONFIG_ACPI))
- WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier));
- if (IS_ENABLED(CONFIG_OF_DYNAMIC))
- WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier));
- i2c_del_driver(&dummy_driver);
-#ifdef CONFIG_I2C_COMPAT
- class_compat_unregister(i2c_adapter_compat_class);
-#endif
- bus_unregister(&i2c_bus_type);
- tracepoint_synchronize_unregister();
-}
-
-/* We must initialize early, because some subsystems register i2c drivers
- * in subsys_initcall() code, but are linked (and initialized) before i2c.
- */
-postcore_initcall(i2c_init);
-module_exit(i2c_exit);
-
-/* ----------------------------------------------------
- * the functional interface to the i2c busses.
- * ----------------------------------------------------
- */
-
-/* Check if val is exceeding the quirk IFF quirk is non 0 */
-#define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk)))
-
-static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg)
-{
- dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n",
- err_msg, msg->addr, msg->len,
- msg->flags & I2C_M_RD ? "read" : "write");
- return -EOPNOTSUPP;
-}
-
-static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
-{
- const struct i2c_adapter_quirks *q = adap->quirks;
- int max_num = q->max_num_msgs, i;
- bool do_len_check = true;
-
- if (q->flags & I2C_AQ_COMB) {
- max_num = 2;
-
- /* special checks for combined messages */
- if (num == 2) {
- if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD)
- return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write");
-
- if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD))
- return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read");
-
- if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr)
- return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr");
-
- if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len))
- return i2c_quirk_error(adap, &msgs[0], "msg too long");
-
- if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len))
- return i2c_quirk_error(adap, &msgs[1], "msg too long");
-
- do_len_check = false;
- }
- }
-
- if (i2c_quirk_exceeded(num, max_num))
- return i2c_quirk_error(adap, &msgs[0], "too many messages");
-
- for (i = 0; i < num; i++) {
- u16 len = msgs[i].len;
-
- if (msgs[i].flags & I2C_M_RD) {
- if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len))
- return i2c_quirk_error(adap, &msgs[i], "msg too long");
- } else {
- if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len))
- return i2c_quirk_error(adap, &msgs[i], "msg too long");
- }
- }
-
- return 0;
-}
-
-/**
- * __i2c_transfer - unlocked flavor of i2c_transfer
- * @adap: Handle to I2C bus
- * @msgs: One or more messages to execute before STOP is issued to
- * terminate the operation; each message begins with a START.
- * @num: Number of messages to be executed.
- *
- * Returns negative errno, else the number of messages executed.
- *
- * Adapter lock must be held when calling this function. No debug logging
- * takes place. adap->algo->master_xfer existence isn't checked.
- */
-int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
-{
- unsigned long orig_jiffies;
- int ret, try;
-
- if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
- return -EOPNOTSUPP;
-
- /* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets
- * enabled. This is an efficient way of keeping the for-loop from
- * being executed when not needed.
- */
- if (static_key_false(&i2c_trace_msg)) {
- int i;
- for (i = 0; i < num; i++)
- if (msgs[i].flags & I2C_M_RD)
- trace_i2c_read(adap, &msgs[i], i);
- else
- trace_i2c_write(adap, &msgs[i], i);
- }
-
- /* Retry automatically on arbitration loss */
- orig_jiffies = jiffies;
- for (ret = 0, try = 0; try <= adap->retries; try++) {
- ret = adap->algo->master_xfer(adap, msgs, num);
- if (ret != -EAGAIN)
- break;
- if (time_after(jiffies, orig_jiffies + adap->timeout))
- break;
- }
-
- if (static_key_false(&i2c_trace_msg)) {
- int i;
- for (i = 0; i < ret; i++)
- if (msgs[i].flags & I2C_M_RD)
- trace_i2c_reply(adap, &msgs[i], i);
- trace_i2c_result(adap, i, ret);
- }
-
- return ret;
-}
-EXPORT_SYMBOL(__i2c_transfer);
-
-/**
- * i2c_transfer - execute a single or combined I2C message
- * @adap: Handle to I2C bus
- * @msgs: One or more messages to execute before STOP is issued to
- * terminate the operation; each message begins with a START.
- * @num: Number of messages to be executed.
- *
- * Returns negative errno, else the number of messages executed.
- *
- * Note that there is no requirement that each message be sent to
- * the same slave address, although that is the most common model.
- */
-int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
-{
- int ret;
-
- /* REVISIT the fault reporting model here is weak:
- *
- * - When we get an error after receiving N bytes from a slave,
- * there is no way to report "N".
- *
- * - When we get a NAK after transmitting N bytes to a slave,
- * there is no way to report "N" ... or to let the master
- * continue executing the rest of this combined message, if
- * that's the appropriate response.
- *
- * - When for example "num" is two and we successfully complete
- * the first message but get an error part way through the
- * second, it's unclear whether that should be reported as
- * one (discarding status on the second message) or errno
- * (discarding status on the first one).
- */
-
- if (adap->algo->master_xfer) {
-#ifdef DEBUG
- for (ret = 0; ret < num; ret++) {
- dev_dbg(&adap->dev,
- "master_xfer[%d] %c, addr=0x%02x, len=%d%s\n",
- ret, (msgs[ret].flags & I2C_M_RD) ? 'R' : 'W',
- msgs[ret].addr, msgs[ret].len,
- (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : "");
- }
-#endif
-
- if (in_atomic() || irqs_disabled()) {
- ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT);
- if (!ret)
- /* I2C activity is ongoing. */
- return -EAGAIN;
- } else {
- i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
- }
-
- ret = __i2c_transfer(adap, msgs, num);
- i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
-
- return ret;
- } else {
- dev_dbg(&adap->dev, "I2C level transfers not supported\n");
- return -EOPNOTSUPP;
- }
-}
-EXPORT_SYMBOL(i2c_transfer);
-
-/**
- * i2c_master_send - issue a single I2C message in master transmit mode
- * @client: Handle to slave device
- * @buf: Data that will be written to the slave
- * @count: How many bytes to write, must be less than 64k since msg.len is u16
- *
- * Returns negative errno, or else the number of bytes written.
- */
-int i2c_master_send(const struct i2c_client *client, const char *buf, int count)
-{
- int ret;
- struct i2c_adapter *adap = client->adapter;
- struct i2c_msg msg;
-
- msg.addr = client->addr;
- msg.flags = client->flags & I2C_M_TEN;
- msg.len = count;
- msg.buf = (char *)buf;
-
- ret = i2c_transfer(adap, &msg, 1);
-
- /*
- * If everything went ok (i.e. 1 msg transmitted), return #bytes
- * transmitted, else error code.
- */
- return (ret == 1) ? count : ret;
-}
-EXPORT_SYMBOL(i2c_master_send);
-
-/**
- * i2c_master_recv - issue a single I2C message in master receive mode
- * @client: Handle to slave device
- * @buf: Where to store data read from slave
- * @count: How many bytes to read, must be less than 64k since msg.len is u16
- *
- * Returns negative errno, or else the number of bytes read.
- */
-int i2c_master_recv(const struct i2c_client *client, char *buf, int count)
-{
- struct i2c_adapter *adap = client->adapter;
- struct i2c_msg msg;
- int ret;
-
- msg.addr = client->addr;
- msg.flags = client->flags & I2C_M_TEN;
- msg.flags |= I2C_M_RD;
- msg.len = count;
- msg.buf = buf;
-
- ret = i2c_transfer(adap, &msg, 1);
-
- /*
- * If everything went ok (i.e. 1 msg received), return #bytes received,
- * else error code.
- */
- return (ret == 1) ? count : ret;
-}
-EXPORT_SYMBOL(i2c_master_recv);
-
-/* ----------------------------------------------------
- * the i2c address scanning function
- * Will not work for 10-bit addresses!
- * ----------------------------------------------------
- */
-
-/*
- * Legacy default probe function, mostly relevant for SMBus. The default
- * probe method is a quick write, but it is known to corrupt the 24RF08
- * EEPROMs due to a state machine bug, and could also irreversibly
- * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f,
- * we use a short byte read instead. Also, some bus drivers don't implement
- * quick write, so we fallback to a byte read in that case too.
- * On x86, there is another special case for FSC hardware monitoring chips,
- * which want regular byte reads (address 0x73.) Fortunately, these are the
- * only known chips using this I2C address on PC hardware.
- * Returns 1 if probe succeeded, 0 if not.
- */
-static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
-{
- int err;
- union i2c_smbus_data dummy;
-
-#ifdef CONFIG_X86
- if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON)
- && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA))
- err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
- I2C_SMBUS_BYTE_DATA, &dummy);
- else
-#endif
- if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50)
- && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
- err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,
- I2C_SMBUS_QUICK, NULL);
- else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE))
- err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
- I2C_SMBUS_BYTE, &dummy);
- else {
- dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n",
- addr);
- err = -EOPNOTSUPP;
- }
-
- return err >= 0;
-}
-
-static int i2c_detect_address(struct i2c_client *temp_client,
- struct i2c_driver *driver)
-{
- struct i2c_board_info info;
- struct i2c_adapter *adapter = temp_client->adapter;
- int addr = temp_client->addr;
- int err;
-
- /* Make sure the address is valid */
- err = i2c_check_7bit_addr_validity_strict(addr);
- if (err) {
- dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
- addr);
- return err;
- }
-
- /* Skip if already in use (7 bit, no need to encode flags) */
- if (i2c_check_addr_busy(adapter, addr))
- return 0;
-
- /* Make sure there is something at this address */
- if (!i2c_default_probe(adapter, addr))
- return 0;
-
- /* Finally call the custom detection function */
- memset(&info, 0, sizeof(struct i2c_board_info));
- info.addr = addr;
- err = driver->detect(temp_client, &info);
- if (err) {
- /* -ENODEV is returned if the detection fails. We catch it
- here as this isn't an error. */
- return err == -ENODEV ? 0 : err;
- }
-
- /* Consistency check */
- if (info.type[0] == '\0') {
- dev_err(&adapter->dev,
- "%s detection function provided no name for 0x%x\n",
- driver->driver.name, addr);
- } else {
- struct i2c_client *client;
-
- /* Detection succeeded, instantiate the device */
- if (adapter->class & I2C_CLASS_DEPRECATED)
- dev_warn(&adapter->dev,
- "This adapter will soon drop class based instantiation of devices. "
- "Please make sure client 0x%02x gets instantiated by other means. "
- "Check 'Documentation/i2c/instantiating-devices' for details.\n",
- info.addr);
-
- dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
- info.type, info.addr);
- client = i2c_new_device(adapter, &info);
- if (client)
- list_add_tail(&client->detected, &driver->clients);
- else
- dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",
- info.type, info.addr);
- }
- return 0;
-}
-
-static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
-{
- const unsigned short *address_list;
- struct i2c_client *temp_client;
- int i, err = 0;
- int adap_id = i2c_adapter_id(adapter);
-
- address_list = driver->address_list;
- if (!driver->detect || !address_list)
- return 0;
-
- /* Warn that the adapter lost class based instantiation */
- if (adapter->class == I2C_CLASS_DEPRECATED) {
- dev_dbg(&adapter->dev,
- "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. "
- "If you need it, check 'Documentation/i2c/instantiating-devices' for alternatives.\n",
- driver->driver.name);
- return 0;
- }
-
- /* Stop here if the classes do not match */
- if (!(adapter->class & driver->class))
- return 0;
-
- /* Set up a temporary client to help detect callback */
- temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
- if (!temp_client)
- return -ENOMEM;
- temp_client->adapter = adapter;
-
- for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
- dev_dbg(&adapter->dev,
- "found normal entry for adapter %d, addr 0x%02x\n",
- adap_id, address_list[i]);
- temp_client->addr = address_list[i];
- err = i2c_detect_address(temp_client, driver);
- if (unlikely(err))
- break;
- }
-
- kfree(temp_client);
- return err;
-}
-
-int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr)
-{
- return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
- I2C_SMBUS_QUICK, NULL) >= 0;
-}
-EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read);
-
-struct i2c_client *
-i2c_new_probed_device(struct i2c_adapter *adap,
- struct i2c_board_info *info,
- unsigned short const *addr_list,
- int (*probe)(struct i2c_adapter *, unsigned short addr))
-{
- int i;
-
- if (!probe)
- probe = i2c_default_probe;
-
- for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
- /* Check address validity */
- if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {
- dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n",
- addr_list[i]);
- continue;
- }
-
- /* Check address availability (7 bit, no need to encode flags) */
- if (i2c_check_addr_busy(adap, addr_list[i])) {
- dev_dbg(&adap->dev,
- "Address 0x%02x already in use, not probing\n",
- addr_list[i]);
- continue;
- }
-
- /* Test address responsiveness */
- if (probe(adap, addr_list[i]))
- break;
- }
-
- if (addr_list[i] == I2C_CLIENT_END) {
- dev_dbg(&adap->dev, "Probing failed, no device found\n");
- return NULL;
- }
-
- info->addr = addr_list[i];
- return i2c_new_device(adap, info);
-}
-EXPORT_SYMBOL_GPL(i2c_new_probed_device);
-
-struct i2c_adapter *i2c_get_adapter(int nr)
-{
- struct i2c_adapter *adapter;
-
- mutex_lock(&core_lock);
- adapter = idr_find(&i2c_adapter_idr, nr);
- if (!adapter)
- goto exit;
-
- if (try_module_get(adapter->owner))
- get_device(&adapter->dev);
- else
- adapter = NULL;
-
- exit:
- mutex_unlock(&core_lock);
- return adapter;
-}
-EXPORT_SYMBOL(i2c_get_adapter);
-
-void i2c_put_adapter(struct i2c_adapter *adap)
-{
- if (!adap)
- return;
-
- put_device(&adap->dev);
- module_put(adap->owner);
-}
-EXPORT_SYMBOL(i2c_put_adapter);
-
-/* The SMBus parts */
-
-#define POLY (0x1070U << 3)
-static u8 crc8(u16 data)
-{
- int i;
-
- for (i = 0; i < 8; i++) {
- if (data & 0x8000)
- data = data ^ POLY;
- data = data << 1;
- }
- return (u8)(data >> 8);
-}
-
-/* Incremental CRC8 over count bytes in the array pointed to by p */
-static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
-{
- int i;
-
- for (i = 0; i < count; i++)
- crc = crc8((crc ^ p[i]) << 8);
- return crc;
-}
-
-/* Assume a 7-bit address, which is reasonable for SMBus */
-static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg)
-{
- /* The address will be sent first */
- u8 addr = i2c_8bit_addr_from_msg(msg);
- pec = i2c_smbus_pec(pec, &addr, 1);
-
- /* The data buffer follows */
- return i2c_smbus_pec(pec, msg->buf, msg->len);
-}
-
-/* Used for write only transactions */
-static inline void i2c_smbus_add_pec(struct i2c_msg *msg)
-{
- msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg);
- msg->len++;
-}
-
-/* Return <0 on CRC error
- If there was a write before this read (most cases) we need to take the
- partial CRC from the write part into account.
- Note that this function does modify the message (we need to decrease the
- message length to hide the CRC byte from the caller). */
-static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg)
-{
- u8 rpec = msg->buf[--msg->len];
- cpec = i2c_smbus_msg_pec(cpec, msg);
-
- if (rpec != cpec) {
- pr_debug("Bad PEC 0x%02x vs. 0x%02x\n",
- rpec, cpec);
- return -EBADMSG;
- }
- return 0;
-}
-
-/**
- * i2c_smbus_read_byte - SMBus "receive byte" protocol
- * @client: Handle to slave device
- *
- * This executes the SMBus "receive byte" protocol, returning negative errno
- * else the byte received from the device.
- */
-s32 i2c_smbus_read_byte(const struct i2c_client *client)
-{
- union i2c_smbus_data data;
- int status;
-
- status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
- I2C_SMBUS_READ, 0,
- I2C_SMBUS_BYTE, &data);
- return (status < 0) ? status : data.byte;
-}
-EXPORT_SYMBOL(i2c_smbus_read_byte);
-
-/**
- * i2c_smbus_write_byte - SMBus "send byte" protocol
- * @client: Handle to slave device
- * @value: Byte to be sent
- *
- * This executes the SMBus "send byte" protocol, returning negative errno
- * else zero on success.
- */
-s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value)
-{
- return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
- I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
-}
-EXPORT_SYMBOL(i2c_smbus_write_byte);
-
-/**
- * i2c_smbus_read_byte_data - SMBus "read byte" protocol
- * @client: Handle to slave device
- * @command: Byte interpreted by slave
- *
- * This executes the SMBus "read byte" protocol, returning negative errno
- * else a data byte received from the device.
- */
-s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command)
-{
- union i2c_smbus_data data;
- int status;
-
- status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
- I2C_SMBUS_READ, command,
- I2C_SMBUS_BYTE_DATA, &data);
- return (status < 0) ? status : data.byte;
-}
-EXPORT_SYMBOL(i2c_smbus_read_byte_data);
-
-/**
- * i2c_smbus_write_byte_data - SMBus "write byte" protocol
- * @client: Handle to slave device
- * @command: Byte interpreted by slave
- * @value: Byte being written
- *
- * This executes the SMBus "write byte" protocol, returning negative errno
- * else zero on success.
- */
-s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command,
- u8 value)
-{
- union i2c_smbus_data data;
- data.byte = value;
- return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
- I2C_SMBUS_WRITE, command,
- I2C_SMBUS_BYTE_DATA, &data);
-}
-EXPORT_SYMBOL(i2c_smbus_write_byte_data);
-
-/**
- * i2c_smbus_read_word_data - SMBus "read word" protocol
- * @client: Handle to slave device
- * @command: Byte interpreted by slave
- *
- * This executes the SMBus "read word" protocol, returning negative errno
- * else a 16-bit unsigned "word" received from the device.
- */
-s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command)
-{
- union i2c_smbus_data data;
- int status;
-
- status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
- I2C_SMBUS_READ, command,
- I2C_SMBUS_WORD_DATA, &data);
- return (status < 0) ? status : data.word;
-}
-EXPORT_SYMBOL(i2c_smbus_read_word_data);
-
-/**
- * i2c_smbus_write_word_data - SMBus "write word" protocol
- * @client: Handle to slave device
- * @command: Byte interpreted by slave
- * @value: 16-bit "word" being written
- *
- * This executes the SMBus "write word" protocol, returning negative errno
- * else zero on success.
- */
-s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command,
- u16 value)
-{
- union i2c_smbus_data data;
- data.word = value;
- return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
- I2C_SMBUS_WRITE, command,
- I2C_SMBUS_WORD_DATA, &data);
-}
-EXPORT_SYMBOL(i2c_smbus_write_word_data);
-
-/**
- * i2c_smbus_read_block_data - SMBus "block read" protocol
- * @client: Handle to slave device
- * @command: Byte interpreted by slave
- * @values: Byte array into which data will be read; big enough to hold
- * the data returned by the slave. SMBus allows at most 32 bytes.
- *
- * This executes the SMBus "block read" protocol, returning negative errno
- * else the number of data bytes in the slave's response.
- *
- * Note that using this function requires that the client's adapter support
- * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers
- * support this; its emulation through I2C messaging relies on a specific
- * mechanism (I2C_M_RECV_LEN) which may not be implemented.
- */
-s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command,
- u8 *values)
-{
- union i2c_smbus_data data;
- int status;
-
- status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
- I2C_SMBUS_READ, command,
- I2C_SMBUS_BLOCK_DATA, &data);
- if (status)
- return status;
-
- memcpy(values, &data.block[1], data.block[0]);
- return data.block[0];
-}
-EXPORT_SYMBOL(i2c_smbus_read_block_data);
-
-/**
- * i2c_smbus_write_block_data - SMBus "block write" protocol
- * @client: Handle to slave device
- * @command: Byte interpreted by slave
- * @length: Size of data block; SMBus allows at most 32 bytes
- * @values: Byte array which will be written.
- *
- * This executes the SMBus "block write" protocol, returning negative errno
- * else zero on success.
- */
-s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command,
- u8 length, const u8 *values)
-{
- union i2c_smbus_data data;
-
- if (length > I2C_SMBUS_BLOCK_MAX)
- length = I2C_SMBUS_BLOCK_MAX;
- data.block[0] = length;
- memcpy(&data.block[1], values, length);
- return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
- I2C_SMBUS_WRITE, command,
- I2C_SMBUS_BLOCK_DATA, &data);
-}
-EXPORT_SYMBOL(i2c_smbus_write_block_data);
-
-/* Returns the number of read bytes */
-s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command,
- u8 length, u8 *values)
-{
- union i2c_smbus_data data;
- int status;
-
- if (length > I2C_SMBUS_BLOCK_MAX)
- length = I2C_SMBUS_BLOCK_MAX;
- data.block[0] = length;
- status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
- I2C_SMBUS_READ, command,
- I2C_SMBUS_I2C_BLOCK_DATA, &data);
- if (status < 0)
- return status;
-
- memcpy(values, &data.block[1], data.block[0]);
- return data.block[0];
-}
-EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
-
-s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command,
- u8 length, const u8 *values)
-{
- union i2c_smbus_data data;
-
- if (length > I2C_SMBUS_BLOCK_MAX)
- length = I2C_SMBUS_BLOCK_MAX;
- data.block[0] = length;
- memcpy(data.block + 1, values, length);
- return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
- I2C_SMBUS_WRITE, command,
- I2C_SMBUS_I2C_BLOCK_DATA, &data);
-}
-EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
-
-/* Simulate a SMBus command using the i2c protocol
- No checking of parameters is done! */
-static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
- unsigned short flags,
- char read_write, u8 command, int size,
- union i2c_smbus_data *data)
-{
- /* So we need to generate a series of msgs. In the case of writing, we
- need to use only one message; when reading, we need two. We initialize
- most things with sane defaults, to keep the code below somewhat
- simpler. */
- unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
- unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
- int num = read_write == I2C_SMBUS_READ ? 2 : 1;
- int i;
- u8 partial_pec = 0;
- int status;
- struct i2c_msg msg[2] = {
- {
- .addr = addr,
- .flags = flags,
- .len = 1,
- .buf = msgbuf0,
- }, {
- .addr = addr,
- .flags = flags | I2C_M_RD,
- .len = 0,
- .buf = msgbuf1,
- },
- };
-
- msgbuf0[0] = command;
- switch (size) {
- case I2C_SMBUS_QUICK:
- msg[0].len = 0;
- /* Special case: The read/write field is used as data */
- msg[0].flags = flags | (read_write == I2C_SMBUS_READ ?
- I2C_M_RD : 0);
- num = 1;
- break;
- case I2C_SMBUS_BYTE:
- if (read_write == I2C_SMBUS_READ) {
- /* Special case: only a read! */
- msg[0].flags = I2C_M_RD | flags;
- num = 1;
- }
- break;
- case I2C_SMBUS_BYTE_DATA:
- if (read_write == I2C_SMBUS_READ)
- msg[1].len = 1;
- else {
- msg[0].len = 2;
- msgbuf0[1] = data->byte;
- }
- break;
- case I2C_SMBUS_WORD_DATA:
- if (read_write == I2C_SMBUS_READ)
- msg[1].len = 2;
- else {
- msg[0].len = 3;
- msgbuf0[1] = data->word & 0xff;
- msgbuf0[2] = data->word >> 8;
- }
- break;
- case I2C_SMBUS_PROC_CALL:
- num = 2; /* Special case */
- read_write = I2C_SMBUS_READ;
- msg[0].len = 3;
- msg[1].len = 2;
- msgbuf0[1] = data->word & 0xff;
- msgbuf0[2] = data->word >> 8;
- break;
- case I2C_SMBUS_BLOCK_DATA:
- if (read_write == I2C_SMBUS_READ) {
- msg[1].flags |= I2C_M_RECV_LEN;
- msg[1].len = 1; /* block length will be added by
- the underlying bus driver */
- } else {
- msg[0].len = data->block[0] + 2;
- if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
- dev_err(&adapter->dev,
- "Invalid block write size %d\n",
- data->block[0]);
- return -EINVAL;
- }
- for (i = 1; i < msg[0].len; i++)
- msgbuf0[i] = data->block[i-1];
- }
- break;
- case I2C_SMBUS_BLOCK_PROC_CALL:
- num = 2; /* Another special case */
- read_write = I2C_SMBUS_READ;
- if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
- dev_err(&adapter->dev,
- "Invalid block write size %d\n",
- data->block[0]);
- return -EINVAL;
- }
- msg[0].len = data->block[0] + 2;
- for (i = 1; i < msg[0].len; i++)
- msgbuf0[i] = data->block[i-1];
- msg[1].flags |= I2C_M_RECV_LEN;
- msg[1].len = 1; /* block length will be added by
- the underlying bus driver */
- break;
- case I2C_SMBUS_I2C_BLOCK_DATA:
- if (read_write == I2C_SMBUS_READ) {
- msg[1].len = data->block[0];
- } else {
- msg[0].len = data->block[0] + 1;
- if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) {
- dev_err(&adapter->dev,
- "Invalid block write size %d\n",
- data->block[0]);
- return -EINVAL;
- }
- for (i = 1; i <= data->block[0]; i++)
- msgbuf0[i] = data->block[i];
- }
- break;
- default:
- dev_err(&adapter->dev, "Unsupported transaction %d\n", size);
- return -EOPNOTSUPP;
- }
-
- i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK
- && size != I2C_SMBUS_I2C_BLOCK_DATA);
- if (i) {
- /* Compute PEC if first message is a write */
- if (!(msg[0].flags & I2C_M_RD)) {
- if (num == 1) /* Write only */
- i2c_smbus_add_pec(&msg[0]);
- else /* Write followed by read */
- partial_pec = i2c_smbus_msg_pec(0, &msg[0]);
- }
- /* Ask for PEC if last message is a read */
- if (msg[num-1].flags & I2C_M_RD)
- msg[num-1].len++;
- }
-
- status = i2c_transfer(adapter, msg, num);
- if (status < 0)
- return status;
-
- /* Check PEC if last message is a read */
- if (i && (msg[num-1].flags & I2C_M_RD)) {
- status = i2c_smbus_check_pec(partial_pec, &msg[num-1]);
- if (status < 0)
- return status;
- }
-
- if (read_write == I2C_SMBUS_READ)
- switch (size) {
- case I2C_SMBUS_BYTE:
- data->byte = msgbuf0[0];
- break;
- case I2C_SMBUS_BYTE_DATA:
- data->byte = msgbuf1[0];
- break;
- case I2C_SMBUS_WORD_DATA:
- case I2C_SMBUS_PROC_CALL:
- data->word = msgbuf1[0] | (msgbuf1[1] << 8);
- break;
- case I2C_SMBUS_I2C_BLOCK_DATA:
- for (i = 0; i < data->block[0]; i++)
- data->block[i+1] = msgbuf1[i];
- break;
- case I2C_SMBUS_BLOCK_DATA:
- case I2C_SMBUS_BLOCK_PROC_CALL:
- for (i = 0; i < msgbuf1[0] + 1; i++)
- data->block[i] = msgbuf1[i];
- break;
- }
- return 0;
-}
-
-/**
- * i2c_smbus_xfer - execute SMBus protocol operations
- * @adapter: Handle to I2C bus
- * @addr: Address of SMBus slave on that bus
- * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC)
- * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE
- * @command: Byte interpreted by slave, for protocols which use such bytes
- * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL
- * @data: Data to be read or written
- *
- * This executes an SMBus protocol operation, and returns a negative
- * errno code else zero on success.
- */
-s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
- char read_write, u8 command, int protocol,
- union i2c_smbus_data *data)
-{
- unsigned long orig_jiffies;
- int try;
- s32 res;
-
- /* If enabled, the following two tracepoints are conditional on
- * read_write and protocol.
- */
- trace_smbus_write(adapter, addr, flags, read_write,
- command, protocol, data);
- trace_smbus_read(adapter, addr, flags, read_write,
- command, protocol);
-
- flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB;
-
- if (adapter->algo->smbus_xfer) {
- i2c_lock_bus(adapter, I2C_LOCK_SEGMENT);
-
- /* Retry automatically on arbitration loss */
- orig_jiffies = jiffies;
- for (res = 0, try = 0; try <= adapter->retries; try++) {
- res = adapter->algo->smbus_xfer(adapter, addr, flags,
- read_write, command,
- protocol, data);
- if (res != -EAGAIN)
- break;
- if (time_after(jiffies,
- orig_jiffies + adapter->timeout))
- break;
- }
- i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT);
-
- if (res != -EOPNOTSUPP || !adapter->algo->master_xfer)
- goto trace;
- /*
- * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't
- * implement native support for the SMBus operation.
- */
- }
-
- res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write,
- command, protocol, data);
-
-trace:
- /* If enabled, the reply tracepoint is conditional on read_write. */
- trace_smbus_reply(adapter, addr, flags, read_write,
- command, protocol, data);
- trace_smbus_result(adapter, addr, flags, read_write,
- command, protocol, res);
-
- return res;
-}
-EXPORT_SYMBOL(i2c_smbus_xfer);
-
-/**
- * i2c_smbus_read_i2c_block_data_or_emulated - read block or emulate
- * @client: Handle to slave device
- * @command: Byte interpreted by slave
- * @length: Size of data block; SMBus allows at most I2C_SMBUS_BLOCK_MAX bytes
- * @values: Byte array into which data will be read; big enough to hold
- * the data returned by the slave. SMBus allows at most
- * I2C_SMBUS_BLOCK_MAX bytes.
- *
- * This executes the SMBus "block read" protocol if supported by the adapter.
- * If block read is not supported, it emulates it using either word or byte
- * read protocols depending on availability.
- *
- * The addresses of the I2C slave device that are accessed with this function
- * must be mapped to a linear region, so that a block read will have the same
- * effect as a byte read. Before using this function you must double-check
- * if the I2C slave does support exchanging a block transfer with a byte
- * transfer.
- */
-s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
- u8 command, u8 length, u8 *values)
-{
- u8 i = 0;
- int status;
-
- if (length > I2C_SMBUS_BLOCK_MAX)
- length = I2C_SMBUS_BLOCK_MAX;
-
- if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
- return i2c_smbus_read_i2c_block_data(client, command, length, values);
-
- if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA))
- return -EOPNOTSUPP;
-
- if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)) {
- while ((i + 2) <= length) {
- status = i2c_smbus_read_word_data(client, command + i);
- if (status < 0)
- return status;
- values[i] = status & 0xff;
- values[i + 1] = status >> 8;
- i += 2;
- }
- }
-
- while (i < length) {
- status = i2c_smbus_read_byte_data(client, command + i);
- if (status < 0)
- return status;
- values[i] = status;
- i++;
- }
-
- return i;
-}
-EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data_or_emulated);
-
-#if IS_ENABLED(CONFIG_I2C_SLAVE)
-int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb)
-{
- int ret;
-
- if (!client || !slave_cb) {
- WARN(1, "insufficient data\n");
- return -EINVAL;
- }
-
- if (!(client->flags & I2C_CLIENT_SLAVE))
- dev_warn(&client->dev, "%s: client slave flag not set. You might see address collisions\n",
- __func__);
-
- if (!(client->flags & I2C_CLIENT_TEN)) {
- /* Enforce stricter address checking */
- ret = i2c_check_7bit_addr_validity_strict(client->addr);
- if (ret) {
- dev_err(&client->dev, "%s: invalid address\n", __func__);
- return ret;
- }
- }
-
- if (!client->adapter->algo->reg_slave) {
- dev_err(&client->dev, "%s: not supported by adapter\n", __func__);
- return -EOPNOTSUPP;
- }
-
- client->slave_cb = slave_cb;
-
- i2c_lock_adapter(client->adapter);
- ret = client->adapter->algo->reg_slave(client);
- i2c_unlock_adapter(client->adapter);
-
- if (ret) {
- client->slave_cb = NULL;
- dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret);
- }
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(i2c_slave_register);
-
-int i2c_slave_unregister(struct i2c_client *client)
-{
- int ret;
-
- if (!client->adapter->algo->unreg_slave) {
- dev_err(&client->dev, "%s: not supported by adapter\n", __func__);
- return -EOPNOTSUPP;
- }
-
- i2c_lock_adapter(client->adapter);
- ret = client->adapter->algo->unreg_slave(client);
- i2c_unlock_adapter(client->adapter);
-
- if (ret == 0)
- client->slave_cb = NULL;
- else
- dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(i2c_slave_unregister);
-
-/**
- * i2c_detect_slave_mode - detect operation mode
- * @dev: The device owning the bus
- *
- * This checks the device nodes for an I2C slave by checking the address
- * used in the reg property. If the address match the I2C_OWN_SLAVE_ADDRESS
- * flag this means the device is configured to act as a I2C slave and it will
- * be listening at that address.
- *
- * Returns true if an I2C own slave address is detected, otherwise returns
- * false.
- */
-bool i2c_detect_slave_mode(struct device *dev)
-{
- if (IS_BUILTIN(CONFIG_OF) && dev->of_node) {
- struct device_node *child;
- u32 reg;
-
- for_each_child_of_node(dev->of_node, child) {
- of_property_read_u32(child, "reg", ®);
- if (reg & I2C_OWN_SLAVE_ADDRESS) {
- of_node_put(child);
- return true;
- }
- }
- } else if (IS_BUILTIN(CONFIG_ACPI) && ACPI_HANDLE(dev)) {
- dev_dbg(dev, "ACPI slave is not supported yet\n");
- }
- return false;
-}
-EXPORT_SYMBOL_GPL(i2c_detect_slave_mode);
-
-#endif
-
-MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
-MODULE_DESCRIPTION("I2C-Bus main module");
-MODULE_LICENSE("GPL");
projects / linux.git / commitdiff