+++ /dev/null
-/*
- * Copyright 2011, Netlogic Microsystems Inc.
- * Copyright 2004, Matt Porter <mporter@kernel.crashing.org>
- *
- * This file is licensed under the terms of the GNU General Public
- * License version 2. This program is licensed "as is" without any
- * warranty of any kind, whether express or implied.
- */
-
-#include <linux/err.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/ioport.h>
-#include <linux/delay.h>
-#include <linux/errno.h>
-#include <linux/i2c.h>
-#include <linux/io.h>
-#include <linux/platform_device.h>
-#include <linux/of_device.h>
-#include <linux/clk.h>
-#include <linux/interrupt.h>
-#include <linux/wait.h>
-
-/* XLR I2C REGISTERS */
-#define XLR_I2C_CFG 0x00
-#define XLR_I2C_CLKDIV 0x01
-#define XLR_I2C_DEVADDR 0x02
-#define XLR_I2C_ADDR 0x03
-#define XLR_I2C_DATAOUT 0x04
-#define XLR_I2C_DATAIN 0x05
-#define XLR_I2C_STATUS 0x06
-#define XLR_I2C_STARTXFR 0x07
-#define XLR_I2C_BYTECNT 0x08
-#define XLR_I2C_HDSTATIM 0x09
-
-/* Sigma Designs additional registers */
-#define XLR_I2C_INT_EN 0x09
-#define XLR_I2C_INT_STAT 0x0a
-
-/* XLR I2C REGISTERS FLAGS */
-#define XLR_I2C_BUS_BUSY 0x01
-#define XLR_I2C_SDOEMPTY 0x02
-#define XLR_I2C_RXRDY 0x04
-#define XLR_I2C_ACK_ERR 0x08
-#define XLR_I2C_ARB_STARTERR 0x30
-
-/* Register Values */
-#define XLR_I2C_CFG_ADDR 0xF8
-#define XLR_I2C_CFG_NOADDR 0xFA
-#define XLR_I2C_STARTXFR_ND 0x02 /* No Data */
-#define XLR_I2C_STARTXFR_RD 0x01 /* Read */
-#define XLR_I2C_STARTXFR_WR 0x00 /* Write */
-
-#define XLR_I2C_TIMEOUT 10 /* timeout per byte in msec */
-
-/*
- * On XLR/XLS, we need to use __raw_ IO to read the I2C registers
- * because they are in the big-endian MMIO area on the SoC.
- *
- * The readl/writel implementation on XLR/XLS byteswaps, because
- * those are for its little-endian PCI space (see arch/mips/Kconfig).
- */
-static inline void xlr_i2c_wreg(u32 __iomem *base, unsigned int reg, u32 val)
-{
- __raw_writel(val, base + reg);
-}
-
-static inline u32 xlr_i2c_rdreg(u32 __iomem *base, unsigned int reg)
-{
- return __raw_readl(base + reg);
-}
-
-#define XLR_I2C_FLAG_IRQ 1
-
-struct xlr_i2c_config {
- u32 flags; /* optional feature support */
- u32 status_busy; /* value of STATUS[0] when busy */
- u32 cfg_extra; /* extra CFG bits to set */
-};
-
-struct xlr_i2c_private {
- struct i2c_adapter adap;
- u32 __iomem *iobase;
- int irq;
- int pos;
- struct i2c_msg *msg;
- const struct xlr_i2c_config *cfg;
- wait_queue_head_t wait;
- struct clk *clk;
-};
-
-static int xlr_i2c_busy(struct xlr_i2c_private *priv, u32 status)
-{
- return (status & XLR_I2C_BUS_BUSY) == priv->cfg->status_busy;
-}
-
-static int xlr_i2c_idle(struct xlr_i2c_private *priv)
-{
- return !xlr_i2c_busy(priv, xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS));
-}
-
-static int xlr_i2c_wait(struct xlr_i2c_private *priv, unsigned long timeout)
-{
- int status;
- int t;
-
- t = wait_event_timeout(priv->wait, xlr_i2c_idle(priv),
- msecs_to_jiffies(timeout));
- if (!t)
- return -ETIMEDOUT;
-
- status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS);
-
- return status & XLR_I2C_ACK_ERR ? -EIO : 0;
-}
-
-static void xlr_i2c_tx_irq(struct xlr_i2c_private *priv, u32 status)
-{
- struct i2c_msg *msg = priv->msg;
-
- if (status & XLR_I2C_SDOEMPTY)
- xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT,
- msg->buf[priv->pos++]);
-}
-
-static void xlr_i2c_rx_irq(struct xlr_i2c_private *priv, u32 status)
-{
- struct i2c_msg *msg = priv->msg;
-
- if (status & XLR_I2C_RXRDY)
- msg->buf[priv->pos++] =
- xlr_i2c_rdreg(priv->iobase, XLR_I2C_DATAIN);
-}
-
-static irqreturn_t xlr_i2c_irq(int irq, void *dev_id)
-{
- struct xlr_i2c_private *priv = dev_id;
- struct i2c_msg *msg = priv->msg;
- u32 int_stat, status;
-
- int_stat = xlr_i2c_rdreg(priv->iobase, XLR_I2C_INT_STAT);
- if (!int_stat)
- return IRQ_NONE;
-
- xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_STAT, int_stat);
-
- if (!msg)
- return IRQ_HANDLED;
-
- status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS);
-
- if (priv->pos < msg->len) {
- if (msg->flags & I2C_M_RD)
- xlr_i2c_rx_irq(priv, status);
- else
- xlr_i2c_tx_irq(priv, status);
- }
-
- if (!xlr_i2c_busy(priv, status))
- wake_up(&priv->wait);
-
- return IRQ_HANDLED;
-}
-
-static int xlr_i2c_tx(struct xlr_i2c_private *priv, u16 len,
- u8 *buf, u16 addr)
-{
- struct i2c_adapter *adap = &priv->adap;
- unsigned long timeout, stoptime, checktime;
- u32 i2c_status;
- int pos, timedout;
- u8 offset;
- u32 xfer;
-
- offset = buf[0];
- xlr_i2c_wreg(priv->iobase, XLR_I2C_ADDR, offset);
- xlr_i2c_wreg(priv->iobase, XLR_I2C_DEVADDR, addr);
- xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG,
- XLR_I2C_CFG_ADDR | priv->cfg->cfg_extra);
-
- timeout = msecs_to_jiffies(XLR_I2C_TIMEOUT);
- stoptime = jiffies + timeout;
- timedout = 0;
-
- if (len == 1) {
- xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 1);
- xfer = XLR_I2C_STARTXFR_ND;
- pos = 1;
- } else {
- xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 2);
- xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, buf[1]);
- xfer = XLR_I2C_STARTXFR_WR;
- pos = 2;
- }
-
- priv->pos = pos;
-
-retry:
- /* retry can only happen on the first byte */
- xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR, xfer);
-
- if (priv->irq > 0)
- return xlr_i2c_wait(priv, XLR_I2C_TIMEOUT * len);
-
- while (!timedout) {
- checktime = jiffies;
- i2c_status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS);
-
- if ((i2c_status & XLR_I2C_SDOEMPTY) && pos < len) {
- xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, buf[pos++]);
-
- /* reset timeout on successful xmit */
- stoptime = jiffies + timeout;
- }
- timedout = time_after(checktime, stoptime);
-
- if (i2c_status & XLR_I2C_ARB_STARTERR) {
- if (timedout)
- break;
- goto retry;
- }
-
- if (i2c_status & XLR_I2C_ACK_ERR)
- return -EIO;
-
- if (!xlr_i2c_busy(priv, i2c_status) && pos >= len)
- return 0;
- }
- dev_err(&adap->dev, "I2C transmit timeout\n");
- return -ETIMEDOUT;
-}
-
-static int xlr_i2c_rx(struct xlr_i2c_private *priv, u16 len, u8 *buf, u16 addr)
-{
- struct i2c_adapter *adap = &priv->adap;
- u32 i2c_status;
- unsigned long timeout, stoptime, checktime;
- int nbytes, timedout;
-
- xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG,
- XLR_I2C_CFG_NOADDR | priv->cfg->cfg_extra);
- xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 1);
- xlr_i2c_wreg(priv->iobase, XLR_I2C_DEVADDR, addr);
-
- priv->pos = 0;
-
- timeout = msecs_to_jiffies(XLR_I2C_TIMEOUT);
- stoptime = jiffies + timeout;
- timedout = 0;
- nbytes = 0;
-retry:
- xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR, XLR_I2C_STARTXFR_RD);
-
- if (priv->irq > 0)
- return xlr_i2c_wait(priv, XLR_I2C_TIMEOUT * len);
-
- while (!timedout) {
- checktime = jiffies;
- i2c_status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS);
- if (i2c_status & XLR_I2C_RXRDY) {
- if (nbytes >= len)
- return -EIO; /* should not happen */
-
- buf[nbytes++] =
- xlr_i2c_rdreg(priv->iobase, XLR_I2C_DATAIN);
-
- /* reset timeout on successful read */
- stoptime = jiffies + timeout;
- }
-
- timedout = time_after(checktime, stoptime);
- if (i2c_status & XLR_I2C_ARB_STARTERR) {
- if (timedout)
- break;
- goto retry;
- }
-
- if (i2c_status & XLR_I2C_ACK_ERR)
- return -EIO;
-
- if (!xlr_i2c_busy(priv, i2c_status))
- return 0;
- }
-
- dev_err(&adap->dev, "I2C receive timeout\n");
- return -ETIMEDOUT;
-}
-
-static int xlr_i2c_xfer(struct i2c_adapter *adap,
- struct i2c_msg *msgs, int num)
-{
- struct i2c_msg *msg;
- int i;
- int ret = 0;
- struct xlr_i2c_private *priv = i2c_get_adapdata(adap);
-
- ret = clk_enable(priv->clk);
- if (ret)
- return ret;
-
- if (priv->irq)
- xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_EN, 0xf);
-
-
- for (i = 0; ret == 0 && i < num; i++) {
- msg = &msgs[i];
- priv->msg = msg;
- if (msg->flags & I2C_M_RD)
- ret = xlr_i2c_rx(priv, msg->len, &msg->buf[0],
- msg->addr);
- else
- ret = xlr_i2c_tx(priv, msg->len, &msg->buf[0],
- msg->addr);
- }
-
- if (priv->irq)
- xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_EN, 0);
-
- clk_disable(priv->clk);
- priv->msg = NULL;
-
- return (ret != 0) ? ret : num;
-}
-
-static u32 xlr_func(struct i2c_adapter *adap)
-{
- /* Emulate SMBUS over I2C */
- return (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) | I2C_FUNC_I2C;
-}
-
-static const struct i2c_algorithm xlr_i2c_algo = {
- .master_xfer = xlr_i2c_xfer,
- .functionality = xlr_func,
-};
-
-static const struct i2c_adapter_quirks xlr_i2c_quirks = {
- .flags = I2C_AQ_NO_ZERO_LEN,
-};
-
-static const struct xlr_i2c_config xlr_i2c_config_default = {
- .status_busy = XLR_I2C_BUS_BUSY,
- .cfg_extra = 0,
-};
-
-static const struct xlr_i2c_config xlr_i2c_config_tangox = {
- .flags = XLR_I2C_FLAG_IRQ,
- .status_busy = 0,
- .cfg_extra = 1 << 8,
-};
-
-static const struct of_device_id xlr_i2c_dt_ids[] = {
- {
- .compatible = "sigma,smp8642-i2c",
- .data = &xlr_i2c_config_tangox,
- },
- { }
-};
-MODULE_DEVICE_TABLE(of, xlr_i2c_dt_ids);
-
-static int xlr_i2c_probe(struct platform_device *pdev)
-{
- const struct of_device_id *match;
- struct xlr_i2c_private *priv;
- struct clk *clk;
- unsigned long clk_rate;
- unsigned long clk_div;
- u32 busfreq;
- int irq;
- int ret;
-
- priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
- if (!priv)
- return -ENOMEM;
-
- match = of_match_device(xlr_i2c_dt_ids, &pdev->dev);
- if (match)
- priv->cfg = match->data;
- else
- priv->cfg = &xlr_i2c_config_default;
-
- priv->iobase = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(priv->iobase))
- return PTR_ERR(priv->iobase);
-
- irq = platform_get_irq(pdev, 0);
-
- if (irq > 0 && (priv->cfg->flags & XLR_I2C_FLAG_IRQ)) {
- priv->irq = irq;
-
- xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_EN, 0);
- xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_STAT, 0xf);
-
- ret = devm_request_irq(&pdev->dev, priv->irq, xlr_i2c_irq,
- IRQF_SHARED, dev_name(&pdev->dev),
- priv);
- if (ret)
- return ret;
-
- init_waitqueue_head(&priv->wait);
- }
-
- if (of_property_read_u32(pdev->dev.of_node, "clock-frequency",
- &busfreq))
- busfreq = I2C_MAX_STANDARD_MODE_FREQ;
-
- clk = devm_clk_get(&pdev->dev, NULL);
- if (!IS_ERR(clk)) {
- ret = clk_prepare_enable(clk);
- if (ret)
- return ret;
-
- clk_rate = clk_get_rate(clk);
- clk_div = DIV_ROUND_UP(clk_rate, 2 * busfreq);
- xlr_i2c_wreg(priv->iobase, XLR_I2C_CLKDIV, clk_div);
-
- clk_disable(clk);
- priv->clk = clk;
- }
-
- priv->adap.dev.parent = &pdev->dev;
- priv->adap.dev.of_node = pdev->dev.of_node;
- priv->adap.owner = THIS_MODULE;
- priv->adap.algo_data = priv;
- priv->adap.algo = &xlr_i2c_algo;
- priv->adap.quirks = &xlr_i2c_quirks;
- priv->adap.nr = pdev->id;
- priv->adap.class = I2C_CLASS_HWMON;
- snprintf(priv->adap.name, sizeof(priv->adap.name), "xlr-i2c");
-
- i2c_set_adapdata(&priv->adap, priv);
- ret = i2c_add_numbered_adapter(&priv->adap);
- if (ret < 0)
- goto err_unprepare_clk;
-
- platform_set_drvdata(pdev, priv);
- dev_info(&priv->adap.dev, "Added I2C Bus.\n");
- return 0;
-
-err_unprepare_clk:
- clk_unprepare(clk);
- return ret;
-}
-
-static int xlr_i2c_remove(struct platform_device *pdev)
-{
- struct xlr_i2c_private *priv;
-
- priv = platform_get_drvdata(pdev);
- i2c_del_adapter(&priv->adap);
- clk_unprepare(priv->clk);
-
- return 0;
-}
-
-static struct platform_driver xlr_i2c_driver = {
- .probe = xlr_i2c_probe,
- .remove = xlr_i2c_remove,
- .driver = {
- .name = "xlr-i2cbus",
- .of_match_table = xlr_i2c_dt_ids,
- },
-};
-
-module_platform_driver(xlr_i2c_driver);
-
-MODULE_AUTHOR("Ganesan Ramalingam <ganesanr@netlogicmicro.com>");
-MODULE_DESCRIPTION("XLR/XLS SoC I2C Controller driver");
-MODULE_LICENSE("GPL v2");
-MODULE_ALIAS("platform:xlr-i2cbus");
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