+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * htc-i2cpld.c
- * Chip driver for an unknown CPLD chip found on omap850 HTC devices like
- * the HTC Wizard and HTC Herald.
- * The cpld is located on the i2c bus and acts as an input/output GPIO
- * extender.
- *
- * Copyright (C) 2009 Cory Maccarrone <darkstar6262@gmail.com>
- *
- * Based on work done in the linwizard project
- * Copyright (C) 2008-2009 Angelo Arrifano <miknix@gmail.com>
- */
-
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/interrupt.h>
-#include <linux/platform_device.h>
-#include <linux/i2c.h>
-#include <linux/irq.h>
-#include <linux/spinlock.h>
-#include <linux/htcpld.h>
-#include <linux/gpio/driver.h>
-#include <linux/gpio/machine.h>
-#include <linux/gpio/consumer.h>
-#include <linux/slab.h>
-
-struct htcpld_chip {
- spinlock_t lock;
-
- /* chip info */
- u8 reset;
- u8 addr;
- struct device *dev;
- struct i2c_client *client;
-
- /* Output details */
- u8 cache_out;
- struct gpio_chip chip_out;
-
- /* Input details */
- u8 cache_in;
- struct gpio_chip chip_in;
-
- u16 irqs_enabled;
- uint irq_start;
- int nirqs;
-
- unsigned int flow_type;
- /*
- * Work structure to allow for setting values outside of any
- * possible interrupt context
- */
- struct work_struct set_val_work;
-};
-
-struct htcpld_data {
- /* irq info */
- u16 irqs_enabled;
- uint irq_start;
- int nirqs;
- uint chained_irq;
- struct gpio_desc *int_reset_gpio_hi;
- struct gpio_desc *int_reset_gpio_lo;
-
- /* htcpld info */
- struct htcpld_chip *chip;
- unsigned int nchips;
-};
-
-/* There does not appear to be a way to proactively mask interrupts
- * on the htcpld chip itself. So, we simply ignore interrupts that
- * aren't desired. */
-static void htcpld_mask(struct irq_data *data)
-{
- struct htcpld_chip *chip = irq_data_get_irq_chip_data(data);
- chip->irqs_enabled &= ~(1 << (data->irq - chip->irq_start));
- pr_debug("HTCPLD mask %d %04x\n", data->irq, chip->irqs_enabled);
-}
-static void htcpld_unmask(struct irq_data *data)
-{
- struct htcpld_chip *chip = irq_data_get_irq_chip_data(data);
- chip->irqs_enabled |= 1 << (data->irq - chip->irq_start);
- pr_debug("HTCPLD unmask %d %04x\n", data->irq, chip->irqs_enabled);
-}
-
-static int htcpld_set_type(struct irq_data *data, unsigned int flags)
-{
- struct htcpld_chip *chip = irq_data_get_irq_chip_data(data);
-
- if (flags & ~IRQ_TYPE_SENSE_MASK)
- return -EINVAL;
-
- /* We only allow edge triggering */
- if (flags & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH))
- return -EINVAL;
-
- chip->flow_type = flags;
- return 0;
-}
-
-static struct irq_chip htcpld_muxed_chip = {
- .name = "htcpld",
- .irq_mask = htcpld_mask,
- .irq_unmask = htcpld_unmask,
- .irq_set_type = htcpld_set_type,
-};
-
-/* To properly dispatch IRQ events, we need to read from the
- * chip. This is an I2C action that could possibly sleep
- * (which is bad in interrupt context) -- so we use a threaded
- * interrupt handler to get around that.
- */
-static irqreturn_t htcpld_handler(int irq, void *dev)
-{
- struct htcpld_data *htcpld = dev;
- unsigned int i;
- unsigned long flags;
- int irqpin;
-
- if (!htcpld) {
- pr_debug("htcpld is null in ISR\n");
- return IRQ_HANDLED;
- }
-
- /*
- * For each chip, do a read of the chip and trigger any interrupts
- * desired. The interrupts will be triggered from LSB to MSB (i.e.
- * bit 0 first, then bit 1, etc.)
- *
- * For chips that have no interrupt range specified, just skip 'em.
- */
- for (i = 0; i < htcpld->nchips; i++) {
- struct htcpld_chip *chip = &htcpld->chip[i];
- struct i2c_client *client;
- int val;
- unsigned long uval, old_val;
-
- if (!chip) {
- pr_debug("chip %d is null in ISR\n", i);
- continue;
- }
-
- if (chip->nirqs == 0)
- continue;
-
- client = chip->client;
- if (!client) {
- pr_debug("client %d is null in ISR\n", i);
- continue;
- }
-
- /* Scan the chip */
- val = i2c_smbus_read_byte_data(client, chip->cache_out);
- if (val < 0) {
- /* Throw a warning and skip this chip */
- dev_warn(chip->dev, "Unable to read from chip: %d\n",
- val);
- continue;
- }
-
- uval = (unsigned long)val;
-
- spin_lock_irqsave(&chip->lock, flags);
-
- /* Save away the old value so we can compare it */
- old_val = chip->cache_in;
-
- /* Write the new value */
- chip->cache_in = uval;
-
- spin_unlock_irqrestore(&chip->lock, flags);
-
- /*
- * For each bit in the data (starting at bit 0), trigger
- * associated interrupts.
- */
- for (irqpin = 0; irqpin < chip->nirqs; irqpin++) {
- unsigned oldb, newb, type = chip->flow_type;
-
- irq = chip->irq_start + irqpin;
-
- /* Run the IRQ handler, but only if the bit value
- * changed, and the proper flags are set */
- oldb = (old_val >> irqpin) & 1;
- newb = (uval >> irqpin) & 1;
-
- if ((!oldb && newb && (type & IRQ_TYPE_EDGE_RISING)) ||
- (oldb && !newb && (type & IRQ_TYPE_EDGE_FALLING))) {
- pr_debug("fire IRQ %d\n", irqpin);
- generic_handle_irq(irq);
- }
- }
- }
-
- /*
- * In order to continue receiving interrupts, the int_reset_gpio must
- * be asserted.
- */
- if (htcpld->int_reset_gpio_hi)
- gpiod_set_value(htcpld->int_reset_gpio_hi, 1);
- if (htcpld->int_reset_gpio_lo)
- gpiod_set_value(htcpld->int_reset_gpio_lo, 0);
-
- return IRQ_HANDLED;
-}
-
-/*
- * The GPIO set routines can be called from interrupt context, especially if,
- * for example they're attached to the led-gpio framework and a trigger is
- * enabled. As such, we declared work above in the htcpld_chip structure,
- * and that work is scheduled in the set routine. The kernel can then run
- * the I2C functions, which will sleep, in process context.
- */
-static void htcpld_chip_set(struct gpio_chip *chip, unsigned offset, int val)
-{
- struct i2c_client *client;
- struct htcpld_chip *chip_data = gpiochip_get_data(chip);
- unsigned long flags;
-
- client = chip_data->client;
- if (!client)
- return;
-
- spin_lock_irqsave(&chip_data->lock, flags);
- if (val)
- chip_data->cache_out |= (1 << offset);
- else
- chip_data->cache_out &= ~(1 << offset);
- spin_unlock_irqrestore(&chip_data->lock, flags);
-
- schedule_work(&(chip_data->set_val_work));
-}
-
-static void htcpld_chip_set_ni(struct work_struct *work)
-{
- struct htcpld_chip *chip_data;
- struct i2c_client *client;
-
- chip_data = container_of(work, struct htcpld_chip, set_val_work);
- client = chip_data->client;
- i2c_smbus_read_byte_data(client, chip_data->cache_out);
-}
-
-static int htcpld_chip_get(struct gpio_chip *chip, unsigned offset)
-{
- struct htcpld_chip *chip_data = gpiochip_get_data(chip);
- u8 cache;
-
- if (!strncmp(chip->label, "htcpld-out", 10)) {
- cache = chip_data->cache_out;
- } else if (!strncmp(chip->label, "htcpld-in", 9)) {
- cache = chip_data->cache_in;
- } else
- return -EINVAL;
-
- return (cache >> offset) & 1;
-}
-
-static int htcpld_direction_output(struct gpio_chip *chip,
- unsigned offset, int value)
-{
- htcpld_chip_set(chip, offset, value);
- return 0;
-}
-
-static int htcpld_direction_input(struct gpio_chip *chip,
- unsigned offset)
-{
- /*
- * No-op: this function can only be called on the input chip.
- * We do however make sure the offset is within range.
- */
- return (offset < chip->ngpio) ? 0 : -EINVAL;
-}
-
-static int htcpld_chip_to_irq(struct gpio_chip *chip, unsigned offset)
-{
- struct htcpld_chip *chip_data = gpiochip_get_data(chip);
-
- if (offset < chip_data->nirqs)
- return chip_data->irq_start + offset;
- else
- return -EINVAL;
-}
-
-static void htcpld_chip_reset(struct i2c_client *client)
-{
- struct htcpld_chip *chip_data = i2c_get_clientdata(client);
- if (!chip_data)
- return;
-
- i2c_smbus_read_byte_data(
- client, (chip_data->cache_out = chip_data->reset));
-}
-
-static int htcpld_setup_chip_irq(
- struct platform_device *pdev,
- int chip_index)
-{
- struct htcpld_data *htcpld;
- struct htcpld_chip *chip;
- unsigned int irq, irq_end;
-
- /* Get the platform and driver data */
- htcpld = platform_get_drvdata(pdev);
- chip = &htcpld->chip[chip_index];
-
- /* Setup irq handlers */
- irq_end = chip->irq_start + chip->nirqs;
- for (irq = chip->irq_start; irq < irq_end; irq++) {
- irq_set_chip_and_handler(irq, &htcpld_muxed_chip,
- handle_simple_irq);
- irq_set_chip_data(irq, chip);
- irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
- }
-
- return 0;
-}
-
-static int htcpld_register_chip_i2c(
- struct platform_device *pdev,
- int chip_index)
-{
- struct htcpld_data *htcpld;
- struct device *dev = &pdev->dev;
- struct htcpld_core_platform_data *pdata;
- struct htcpld_chip *chip;
- struct htcpld_chip_platform_data *plat_chip_data;
- struct i2c_adapter *adapter;
- struct i2c_client *client;
- struct i2c_board_info info;
-
- /* Get the platform and driver data */
- pdata = dev_get_platdata(dev);
- htcpld = platform_get_drvdata(pdev);
- chip = &htcpld->chip[chip_index];
- plat_chip_data = &pdata->chip[chip_index];
-
- adapter = i2c_get_adapter(pdata->i2c_adapter_id);
- if (!adapter) {
- /* Eek, no such I2C adapter! Bail out. */
- dev_warn(dev, "Chip at i2c address 0x%x: Invalid i2c adapter %d\n",
- plat_chip_data->addr, pdata->i2c_adapter_id);
- return -ENODEV;
- }
-
- if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
- dev_warn(dev, "i2c adapter %d non-functional\n",
- pdata->i2c_adapter_id);
- i2c_put_adapter(adapter);
- return -EINVAL;
- }
-
- memset(&info, 0, sizeof(struct i2c_board_info));
- info.addr = plat_chip_data->addr;
- strscpy(info.type, "htcpld-chip", I2C_NAME_SIZE);
- info.platform_data = chip;
-
- /* Add the I2C device. This calls the probe() function. */
- client = i2c_new_client_device(adapter, &info);
- if (IS_ERR(client)) {
- /* I2C device registration failed, contineu with the next */
- dev_warn(dev, "Unable to add I2C device for 0x%x\n",
- plat_chip_data->addr);
- i2c_put_adapter(adapter);
- return PTR_ERR(client);
- }
-
- i2c_set_clientdata(client, chip);
- snprintf(client->name, I2C_NAME_SIZE, "Chip_0x%x", client->addr);
- chip->client = client;
-
- /* Reset the chip */
- htcpld_chip_reset(client);
- chip->cache_in = i2c_smbus_read_byte_data(client, chip->cache_out);
-
- return 0;
-}
-
-static void htcpld_unregister_chip_i2c(
- struct platform_device *pdev,
- int chip_index)
-{
- struct htcpld_data *htcpld;
- struct htcpld_chip *chip;
-
- /* Get the platform and driver data */
- htcpld = platform_get_drvdata(pdev);
- chip = &htcpld->chip[chip_index];
-
- i2c_unregister_device(chip->client);
-}
-
-static int htcpld_register_chip_gpio(
- struct platform_device *pdev,
- int chip_index)
-{
- struct htcpld_data *htcpld;
- struct device *dev = &pdev->dev;
- struct htcpld_core_platform_data *pdata;
- struct htcpld_chip *chip;
- struct htcpld_chip_platform_data *plat_chip_data;
- struct gpio_chip *gpio_chip;
- int ret = 0;
-
- /* Get the platform and driver data */
- pdata = dev_get_platdata(dev);
- htcpld = platform_get_drvdata(pdev);
- chip = &htcpld->chip[chip_index];
- plat_chip_data = &pdata->chip[chip_index];
-
- /* Setup the GPIO chips */
- gpio_chip = &(chip->chip_out);
- gpio_chip->label = "htcpld-out";
- gpio_chip->parent = dev;
- gpio_chip->owner = THIS_MODULE;
- gpio_chip->get = htcpld_chip_get;
- gpio_chip->set = htcpld_chip_set;
- gpio_chip->direction_input = NULL;
- gpio_chip->direction_output = htcpld_direction_output;
- gpio_chip->base = plat_chip_data->gpio_out_base;
- gpio_chip->ngpio = plat_chip_data->num_gpios;
-
- gpio_chip = &(chip->chip_in);
- gpio_chip->label = "htcpld-in";
- gpio_chip->parent = dev;
- gpio_chip->owner = THIS_MODULE;
- gpio_chip->get = htcpld_chip_get;
- gpio_chip->set = NULL;
- gpio_chip->direction_input = htcpld_direction_input;
- gpio_chip->direction_output = NULL;
- gpio_chip->to_irq = htcpld_chip_to_irq;
- gpio_chip->base = plat_chip_data->gpio_in_base;
- gpio_chip->ngpio = plat_chip_data->num_gpios;
-
- /* Add the GPIO chips */
- ret = gpiochip_add_data(&(chip->chip_out), chip);
- if (ret) {
- dev_warn(dev, "Unable to register output GPIOs for 0x%x: %d\n",
- plat_chip_data->addr, ret);
- return ret;
- }
-
- ret = gpiochip_add_data(&(chip->chip_in), chip);
- if (ret) {
- dev_warn(dev, "Unable to register input GPIOs for 0x%x: %d\n",
- plat_chip_data->addr, ret);
- gpiochip_remove(&(chip->chip_out));
- return ret;
- }
-
- return 0;
-}
-
-static int htcpld_setup_chips(struct platform_device *pdev)
-{
- struct htcpld_data *htcpld;
- struct device *dev = &pdev->dev;
- struct htcpld_core_platform_data *pdata;
- int i;
-
- /* Get the platform and driver data */
- pdata = dev_get_platdata(dev);
- htcpld = platform_get_drvdata(pdev);
-
- /* Setup each chip's output GPIOs */
- htcpld->nchips = pdata->num_chip;
- htcpld->chip = devm_kcalloc(dev,
- htcpld->nchips,
- sizeof(struct htcpld_chip),
- GFP_KERNEL);
- if (!htcpld->chip)
- return -ENOMEM;
-
- /* Add the chips as best we can */
- for (i = 0; i < htcpld->nchips; i++) {
- int ret;
-
- /* Setup the HTCPLD chips */
- htcpld->chip[i].reset = pdata->chip[i].reset;
- htcpld->chip[i].cache_out = pdata->chip[i].reset;
- htcpld->chip[i].cache_in = 0;
- htcpld->chip[i].dev = dev;
- htcpld->chip[i].irq_start = pdata->chip[i].irq_base;
- htcpld->chip[i].nirqs = pdata->chip[i].num_irqs;
-
- INIT_WORK(&(htcpld->chip[i].set_val_work), &htcpld_chip_set_ni);
- spin_lock_init(&(htcpld->chip[i].lock));
-
- /* Setup the interrupts for the chip */
- if (htcpld->chained_irq) {
- ret = htcpld_setup_chip_irq(pdev, i);
- if (ret)
- continue;
- }
-
- /* Register the chip with I2C */
- ret = htcpld_register_chip_i2c(pdev, i);
- if (ret)
- continue;
-
-
- /* Register the chips with the GPIO subsystem */
- ret = htcpld_register_chip_gpio(pdev, i);
- if (ret) {
- /* Unregister the chip from i2c and continue */
- htcpld_unregister_chip_i2c(pdev, i);
- continue;
- }
-
- dev_info(dev, "Registered chip at 0x%x\n", pdata->chip[i].addr);
- }
-
- return 0;
-}
-
-static int htcpld_core_probe(struct platform_device *pdev)
-{
- struct htcpld_data *htcpld;
- struct device *dev = &pdev->dev;
- struct htcpld_core_platform_data *pdata;
- struct resource *res;
- int ret = 0;
-
- if (!dev)
- return -ENODEV;
-
- pdata = dev_get_platdata(dev);
- if (!pdata) {
- dev_warn(dev, "Platform data not found for htcpld core!\n");
- return -ENXIO;
- }
-
- htcpld = devm_kzalloc(dev, sizeof(struct htcpld_data), GFP_KERNEL);
- if (!htcpld)
- return -ENOMEM;
-
- /* Find chained irq */
- res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
- if (res) {
- int flags;
- htcpld->chained_irq = res->start;
-
- /* Setup the chained interrupt handler */
- flags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING |
- IRQF_ONESHOT;
- ret = request_threaded_irq(htcpld->chained_irq,
- NULL, htcpld_handler,
- flags, pdev->name, htcpld);
- if (ret) {
- dev_warn(dev, "Unable to setup chained irq handler: %d\n", ret);
- return ret;
- } else
- device_init_wakeup(dev, 0);
- }
-
- /* Set the driver data */
- platform_set_drvdata(pdev, htcpld);
-
- /* Setup the htcpld chips */
- ret = htcpld_setup_chips(pdev);
- if (ret)
- return ret;
-
- /* Request the GPIO(s) for the int reset and set them up */
- htcpld->int_reset_gpio_hi = gpiochip_request_own_desc(&htcpld->chip[2].chip_out,
- 7, "htcpld-core", GPIO_ACTIVE_HIGH,
- GPIOD_OUT_HIGH);
- if (IS_ERR(htcpld->int_reset_gpio_hi)) {
- /*
- * If it failed, that sucks, but we can probably
- * continue on without it.
- */
- htcpld->int_reset_gpio_hi = NULL;
- dev_warn(dev, "Unable to request int_reset_gpio_hi -- interrupts may not work\n");
- }
-
- htcpld->int_reset_gpio_lo = gpiochip_request_own_desc(&htcpld->chip[2].chip_out,
- 0, "htcpld-core", GPIO_ACTIVE_HIGH,
- GPIOD_OUT_LOW);
- if (IS_ERR(htcpld->int_reset_gpio_lo)) {
- /*
- * If it failed, that sucks, but we can probably
- * continue on without it.
- */
- htcpld->int_reset_gpio_lo = NULL;
- dev_warn(dev, "Unable to request int_reset_gpio_lo -- interrupts may not work\n");
- }
-
- dev_info(dev, "Initialized successfully\n");
- return 0;
-}
-
-/* The I2C Driver -- used internally */
-static const struct i2c_device_id htcpld_chip_id[] = {
- { "htcpld-chip", 0 },
- { }
-};
-
-static struct i2c_driver htcpld_chip_driver = {
- .driver = {
- .name = "htcpld-chip",
- },
- .id_table = htcpld_chip_id,
-};
-
-/* The Core Driver */
-static struct platform_driver htcpld_core_driver = {
- .driver = {
- .name = "i2c-htcpld",
- },
-};
-
-static int __init htcpld_core_init(void)
-{
- int ret;
-
- /* Register the I2C Chip driver */
- ret = i2c_add_driver(&htcpld_chip_driver);
- if (ret)
- return ret;
-
- /* Probe for our chips */
- return platform_driver_probe(&htcpld_core_driver, htcpld_core_probe);
-}
-device_initcall(htcpld_core_init);
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