Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 991 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
new file mode 100644
index 000000000..11caafa0e
--- /dev/null
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -0,0 +1,991 @@
+/*
+ * TI DAVINCI I2C adapter driver.
+ *
+ * Copyright (C) 2006 Texas Instruments.
+ * Copyright (C) 2007 MontaVista Software Inc.
+ *
+ * Updated by Vinod & Sudhakar Feb 2005
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * 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.
+ * ----------------------------------------------------------------------------
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/cpufreq.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of_device.h>
+#include <linux/platform_data/i2c-davinci.h>
+#include <linux/pm_runtime.h>
+
+/* ----- global defines ----------------------------------------------- */
+
+#define DAVINCI_I2C_TIMEOUT	(1*HZ)
+#define DAVINCI_I2C_MAX_TRIES	2
+#define DAVINCI_I2C_OWN_ADDRESS	0x08
+#define I2C_DAVINCI_INTR_ALL    (DAVINCI_I2C_IMR_SCD | \
+				 DAVINCI_I2C_IMR_ARDY | \
+				 DAVINCI_I2C_IMR_NACK | \
+				 DAVINCI_I2C_IMR_AL)
+
+#define DAVINCI_I2C_OAR_REG	0x00
+#define DAVINCI_I2C_IMR_REG	0x04
+#define DAVINCI_I2C_STR_REG	0x08
+#define DAVINCI_I2C_CLKL_REG	0x0c
+#define DAVINCI_I2C_CLKH_REG	0x10
+#define DAVINCI_I2C_CNT_REG	0x14
+#define DAVINCI_I2C_DRR_REG	0x18
+#define DAVINCI_I2C_SAR_REG	0x1c
+#define DAVINCI_I2C_DXR_REG	0x20
+#define DAVINCI_I2C_MDR_REG	0x24
+#define DAVINCI_I2C_IVR_REG	0x28
+#define DAVINCI_I2C_EMDR_REG	0x2c
+#define DAVINCI_I2C_PSC_REG	0x30
+#define DAVINCI_I2C_FUNC_REG	0x48
+#define DAVINCI_I2C_DIR_REG	0x4c
+#define DAVINCI_I2C_DIN_REG	0x50
+#define DAVINCI_I2C_DOUT_REG	0x54
+#define DAVINCI_I2C_DSET_REG	0x58
+#define DAVINCI_I2C_DCLR_REG	0x5c
+
+#define DAVINCI_I2C_IVR_AAS	0x07
+#define DAVINCI_I2C_IVR_SCD	0x06
+#define DAVINCI_I2C_IVR_XRDY	0x05
+#define DAVINCI_I2C_IVR_RDR	0x04
+#define DAVINCI_I2C_IVR_ARDY	0x03
+#define DAVINCI_I2C_IVR_NACK	0x02
+#define DAVINCI_I2C_IVR_AL	0x01
+
+#define DAVINCI_I2C_STR_BB	BIT(12)
+#define DAVINCI_I2C_STR_RSFULL	BIT(11)
+#define DAVINCI_I2C_STR_SCD	BIT(5)
+#define DAVINCI_I2C_STR_ARDY	BIT(2)
+#define DAVINCI_I2C_STR_NACK	BIT(1)
+#define DAVINCI_I2C_STR_AL	BIT(0)
+
+#define DAVINCI_I2C_MDR_NACK	BIT(15)
+#define DAVINCI_I2C_MDR_STT	BIT(13)
+#define DAVINCI_I2C_MDR_STP	BIT(11)
+#define DAVINCI_I2C_MDR_MST	BIT(10)
+#define DAVINCI_I2C_MDR_TRX	BIT(9)
+#define DAVINCI_I2C_MDR_XA	BIT(8)
+#define DAVINCI_I2C_MDR_RM	BIT(7)
+#define DAVINCI_I2C_MDR_IRS	BIT(5)
+
+#define DAVINCI_I2C_IMR_AAS	BIT(6)
+#define DAVINCI_I2C_IMR_SCD	BIT(5)
+#define DAVINCI_I2C_IMR_XRDY	BIT(4)
+#define DAVINCI_I2C_IMR_RRDY	BIT(3)
+#define DAVINCI_I2C_IMR_ARDY	BIT(2)
+#define DAVINCI_I2C_IMR_NACK	BIT(1)
+#define DAVINCI_I2C_IMR_AL	BIT(0)
+
+/* set SDA and SCL as GPIO */
+#define DAVINCI_I2C_FUNC_PFUNC0	BIT(0)
+
+/* set SCL as output when used as GPIO*/
+#define DAVINCI_I2C_DIR_PDIR0	BIT(0)
+/* set SDA as output when used as GPIO*/
+#define DAVINCI_I2C_DIR_PDIR1	BIT(1)
+
+/* read SCL GPIO level */
+#define DAVINCI_I2C_DIN_PDIN0 BIT(0)
+/* read SDA GPIO level */
+#define DAVINCI_I2C_DIN_PDIN1 BIT(1)
+
+/*set the SCL GPIO high */
+#define DAVINCI_I2C_DSET_PDSET0	BIT(0)
+/*set the SDA GPIO high */
+#define DAVINCI_I2C_DSET_PDSET1	BIT(1)
+
+/* set the SCL GPIO low */
+#define DAVINCI_I2C_DCLR_PDCLR0	BIT(0)
+/* set the SDA GPIO low */
+#define DAVINCI_I2C_DCLR_PDCLR1	BIT(1)
+
+/* timeout for pm runtime autosuspend */
+#define DAVINCI_I2C_PM_TIMEOUT	1000	/* ms */
+
+struct davinci_i2c_dev {
+	struct device           *dev;
+	void __iomem		*base;
+	struct completion	cmd_complete;
+	struct clk              *clk;
+	int			cmd_err;
+	u8			*buf;
+	size_t			buf_len;
+	int			irq;
+	int			stop;
+	u8			terminate;
+	struct i2c_adapter	adapter;
+#ifdef CONFIG_CPU_FREQ
+	struct notifier_block	freq_transition;
+#endif
+	struct davinci_i2c_platform_data *pdata;
+};
+
+/* default platform data to use if not supplied in the platform_device */
+static struct davinci_i2c_platform_data davinci_i2c_platform_data_default = {
+	.bus_freq	= 100,
+	.bus_delay	= 0,
+};
+
+static inline void davinci_i2c_write_reg(struct davinci_i2c_dev *i2c_dev,
+					 int reg, u16 val)
+{
+	writew_relaxed(val, i2c_dev->base + reg);
+}
+
+static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg)
+{
+	return readw_relaxed(i2c_dev->base + reg);
+}
+
+static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev,
+								int val)
+{
+	u16 w;
+
+	w = davinci_i2c_read_reg(i2c_dev, DAVINCI_I2C_MDR_REG);
+	if (!val)	/* put I2C into reset */
+		w &= ~DAVINCI_I2C_MDR_IRS;
+	else		/* take I2C out of reset */
+		w |= DAVINCI_I2C_MDR_IRS;
+
+	davinci_i2c_write_reg(i2c_dev, DAVINCI_I2C_MDR_REG, w);
+}
+
+static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
+{
+	struct davinci_i2c_platform_data *pdata = dev->pdata;
+	u16 psc;
+	u32 clk;
+	u32 d;
+	u32 clkh;
+	u32 clkl;
+	u32 input_clock = clk_get_rate(dev->clk);
+	struct device_node *of_node = dev->dev->of_node;
+
+	/* NOTE: I2C Clock divider programming info
+	 * As per I2C specs the following formulas provide prescaler
+	 * and low/high divider values
+	 * input clk --> PSC Div -----------> ICCL/H Div --> output clock
+	 *                       module clk
+	 *
+	 * output clk = module clk / (PSC + 1) [ (ICCL + d) + (ICCH + d) ]
+	 *
+	 * Thus,
+	 * (ICCL + ICCH) = clk = (input clk / ((psc +1) * output clk)) - 2d;
+	 *
+	 * where if PSC == 0, d = 7,
+	 *       if PSC == 1, d = 6
+	 *       if PSC > 1 , d = 5
+	 *
+	 * Note:
+	 * d is always 6 on Keystone I2C controller
+	 */
+
+	/*
+	 * Both Davinci and current Keystone User Guides recommend a value
+	 * between 7MHz and 12MHz. In reality 7MHz module clock doesn't
+	 * always produce enough margin between SDA and SCL transitions.
+	 * Measurements show that the higher the module clock is, the
+	 * bigger is the margin, providing more reliable communication.
+	 * So we better target for 12MHz.
+	 */
+	psc = (input_clock / 12000000) - 1;
+	if ((input_clock / (psc + 1)) > 12000000)
+		psc++;	/* better to run under spec than over */
+	d = (psc >= 2) ? 5 : 7 - psc;
+
+	if (of_node && of_device_is_compatible(of_node, "ti,keystone-i2c"))
+		d = 6;
+
+	clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000));
+	/* Avoid driving the bus too fast because of rounding errors above */
+	if (input_clock / (psc + 1) / clk > pdata->bus_freq * 1000)
+		clk++;
+	/*
+	 * According to I2C-BUS Spec 2.1, in FAST-MODE LOW period should be at
+	 * least 1.3uS, which is not the case with 50% duty cycle. Driving HIGH
+	 * to LOW ratio as 1 to 2 is more safe.
+	 */
+	if (pdata->bus_freq > 100)
+		clkl = (clk << 1) / 3;
+	else
+		clkl = (clk >> 1);
+	/*
+	 * It's not always possible to have 1 to 2 ratio when d=7, so fall back
+	 * to minimal possible clkh in this case.
+	 *
+	 * Note:
+	 * CLKH is not allowed to be 0, in this case I2C clock is not generated
+	 * at all
+	 */
+	if (clk > clkl + d) {
+		clkh = clk - clkl - d;
+		clkl -= d;
+	} else {
+		clkh = 1;
+		clkl = clk - (d << 1);
+	}
+
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_PSC_REG, psc);
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl);
+
+	dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk);
+}
+
+/*
+ * This function configures I2C and brings I2C out of reset.
+ * This function is called during I2C init function. This function
+ * also gets called if I2C encounters any errors.
+ */
+static int i2c_davinci_init(struct davinci_i2c_dev *dev)
+{
+	struct davinci_i2c_platform_data *pdata = dev->pdata;
+
+	/* put I2C into reset */
+	davinci_i2c_reset_ctrl(dev, 0);
+
+	/* compute clock dividers */
+	i2c_davinci_calc_clk_dividers(dev);
+
+	/* Respond at reserved "SMBus Host" slave address" (and zero);
+	 * we seem to have no option to not respond...
+	 */
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, DAVINCI_I2C_OWN_ADDRESS);
+
+	dev_dbg(dev->dev, "PSC  = %d\n",
+		davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG));
+	dev_dbg(dev->dev, "CLKL = %d\n",
+		davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKL_REG));
+	dev_dbg(dev->dev, "CLKH = %d\n",
+		davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKH_REG));
+	dev_dbg(dev->dev, "bus_freq = %dkHz, bus_delay = %d\n",
+		pdata->bus_freq, pdata->bus_delay);
+
+
+	/* Take the I2C module out of reset: */
+	davinci_i2c_reset_ctrl(dev, 1);
+
+	/* Enable interrupts */
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, I2C_DAVINCI_INTR_ALL);
+
+	return 0;
+}
+
+/*
+ * This routine does i2c bus recovery by using i2c_generic_scl_recovery
+ * which is provided by I2C Bus recovery infrastructure.
+ */
+static void davinci_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+	struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+
+	/* Disable interrupts */
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, 0);
+
+	/* put I2C into reset */
+	davinci_i2c_reset_ctrl(dev, 0);
+}
+
+static void davinci_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+	struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+
+	i2c_davinci_init(dev);
+}
+
+static struct i2c_bus_recovery_info davinci_i2c_gpio_recovery_info = {
+	.recover_bus = i2c_generic_scl_recovery,
+	.prepare_recovery = davinci_i2c_prepare_recovery,
+	.unprepare_recovery = davinci_i2c_unprepare_recovery,
+};
+
+static void davinci_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+	struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+
+	if (val)
+		davinci_i2c_write_reg(dev, DAVINCI_I2C_DSET_REG,
+				      DAVINCI_I2C_DSET_PDSET0);
+	else
+		davinci_i2c_write_reg(dev, DAVINCI_I2C_DCLR_REG,
+				      DAVINCI_I2C_DCLR_PDCLR0);
+}
+
+static int davinci_i2c_get_scl(struct i2c_adapter *adap)
+{
+	struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+	int val;
+
+	/* read the state of SCL */
+	val = davinci_i2c_read_reg(dev, DAVINCI_I2C_DIN_REG);
+	return val & DAVINCI_I2C_DIN_PDIN0;
+}
+
+static int davinci_i2c_get_sda(struct i2c_adapter *adap)
+{
+	struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+	int val;
+
+	/* read the state of SDA */
+	val = davinci_i2c_read_reg(dev, DAVINCI_I2C_DIN_REG);
+	return val & DAVINCI_I2C_DIN_PDIN1;
+}
+
+static void davinci_i2c_scl_prepare_recovery(struct i2c_adapter *adap)
+{
+	struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+
+	davinci_i2c_prepare_recovery(adap);
+
+	/* SCL output, SDA input */
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_DIR_REG, DAVINCI_I2C_DIR_PDIR0);
+
+	/* change to GPIO mode */
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_FUNC_REG,
+			      DAVINCI_I2C_FUNC_PFUNC0);
+}
+
+static void davinci_i2c_scl_unprepare_recovery(struct i2c_adapter *adap)
+{
+	struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+
+	/* change back to I2C mode */
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_FUNC_REG, 0);
+
+	davinci_i2c_unprepare_recovery(adap);
+}
+
+static struct i2c_bus_recovery_info davinci_i2c_scl_recovery_info = {
+	.recover_bus = i2c_generic_scl_recovery,
+	.set_scl = davinci_i2c_set_scl,
+	.get_scl = davinci_i2c_get_scl,
+	.get_sda = davinci_i2c_get_sda,
+	.prepare_recovery = davinci_i2c_scl_prepare_recovery,
+	.unprepare_recovery = davinci_i2c_scl_unprepare_recovery,
+};
+
+/*
+ * Waiting for bus not busy
+ */
+static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev)
+{
+	unsigned long timeout = jiffies + dev->adapter.timeout;
+
+	do {
+		if (!(davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB))
+			return 0;
+		schedule_timeout_uninterruptible(1);
+	} while (time_before_eq(jiffies, timeout));
+
+	dev_warn(dev->dev, "timeout waiting for bus ready\n");
+	i2c_recover_bus(&dev->adapter);
+
+	/*
+	 * if bus is still "busy" here, it's most probably a HW problem like
+	 * short-circuit
+	 */
+	if (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB)
+		return -EIO;
+
+	return 0;
+}
+
+/*
+ * Low level master read/write transaction. This function is called
+ * from i2c_davinci_xfer.
+ */
+static int
+i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
+{
+	struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+	struct davinci_i2c_platform_data *pdata = dev->pdata;
+	u32 flag;
+	u16 w;
+	unsigned long time_left;
+
+	if (msg->addr == DAVINCI_I2C_OWN_ADDRESS) {
+		dev_warn(dev->dev, "transfer to own address aborted\n");
+		return -EADDRNOTAVAIL;
+	}
+
+	/* Introduce a delay, required for some boards (e.g Davinci EVM) */
+	if (pdata->bus_delay)
+		udelay(pdata->bus_delay);
+
+	/* set the slave address */
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_SAR_REG, msg->addr);
+
+	dev->buf = msg->buf;
+	dev->buf_len = msg->len;
+	dev->stop = stop;
+
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len);
+
+	reinit_completion(&dev->cmd_complete);
+	dev->cmd_err = 0;
+
+	/* Take I2C out of reset and configure it as master */
+	flag = DAVINCI_I2C_MDR_IRS | DAVINCI_I2C_MDR_MST;
+
+	/* if the slave address is ten bit address, enable XA bit */
+	if (msg->flags & I2C_M_TEN)
+		flag |= DAVINCI_I2C_MDR_XA;
+	if (!(msg->flags & I2C_M_RD))
+		flag |= DAVINCI_I2C_MDR_TRX;
+	if (msg->len == 0)
+		flag |= DAVINCI_I2C_MDR_RM;
+
+	/* Enable receive or transmit interrupts */
+	w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG);
+	if (msg->flags & I2C_M_RD)
+		w |= DAVINCI_I2C_IMR_RRDY;
+	else
+		w |= DAVINCI_I2C_IMR_XRDY;
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w);
+
+	dev->terminate = 0;
+
+	/*
+	 * Write mode register first as needed for correct behaviour
+	 * on OMAP-L138, but don't set STT yet to avoid a race with XRDY
+	 * occurring before we have loaded DXR
+	 */
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
+
+	/*
+	 * First byte should be set here, not after interrupt,
+	 * because transmit-data-ready interrupt can come before
+	 * NACK-interrupt during sending of previous message and
+	 * ICDXR may have wrong data
+	 * It also saves us one interrupt, slightly faster
+	 */
+	if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) {
+		davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++);
+		dev->buf_len--;
+	}
+
+	/* Set STT to begin transmit now DXR is loaded */
+	flag |= DAVINCI_I2C_MDR_STT;
+	if (stop && msg->len != 0)
+		flag |= DAVINCI_I2C_MDR_STP;
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
+
+	time_left = wait_for_completion_timeout(&dev->cmd_complete,
+						dev->adapter.timeout);
+	if (!time_left) {
+		dev_err(dev->dev, "controller timed out\n");
+		i2c_recover_bus(adap);
+		dev->buf_len = 0;
+		return -ETIMEDOUT;
+	}
+	if (dev->buf_len) {
+		/* This should be 0 if all bytes were transferred
+		 * or dev->cmd_err denotes an error.
+		 */
+		dev_err(dev->dev, "abnormal termination buf_len=%zu\n",
+			dev->buf_len);
+		dev->terminate = 1;
+		wmb();
+		dev->buf_len = 0;
+		return -EREMOTEIO;
+	}
+
+	/* no error */
+	if (likely(!dev->cmd_err))
+		return msg->len;
+
+	/* We have an error */
+	if (dev->cmd_err & DAVINCI_I2C_STR_AL) {
+		i2c_davinci_init(dev);
+		return -EIO;
+	}
+
+	if (dev->cmd_err & DAVINCI_I2C_STR_NACK) {
+		if (msg->flags & I2C_M_IGNORE_NAK)
+			return msg->len;
+		w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
+		w |= DAVINCI_I2C_MDR_STP;
+		davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
+		return -EREMOTEIO;
+	}
+	return -EIO;
+}
+
+/*
+ * Prepare controller for a transaction and call i2c_davinci_xfer_msg
+ */
+static int
+i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+	struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
+	int i;
+	int ret;
+
+	dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
+
+	ret = pm_runtime_get_sync(dev->dev);
+	if (ret < 0) {
+		dev_err(dev->dev, "Failed to runtime_get device: %d\n", ret);
+		pm_runtime_put_noidle(dev->dev);
+		return ret;
+	}
+
+	ret = i2c_davinci_wait_bus_not_busy(dev);
+	if (ret < 0) {
+		dev_warn(dev->dev, "timeout waiting for bus ready\n");
+		goto out;
+	}
+
+	for (i = 0; i < num; i++) {
+		ret = i2c_davinci_xfer_msg(adap, &msgs[i], (i == (num - 1)));
+		dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num,
+			ret);
+		if (ret < 0)
+			goto out;
+	}
+
+	ret = num;
+
+out:
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
+
+	return ret;
+}
+
+static u32 i2c_davinci_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static void terminate_read(struct davinci_i2c_dev *dev)
+{
+	u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
+	w |= DAVINCI_I2C_MDR_NACK;
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
+
+	/* Throw away data */
+	davinci_i2c_read_reg(dev, DAVINCI_I2C_DRR_REG);
+	if (!dev->terminate)
+		dev_err(dev->dev, "RDR IRQ while no data requested\n");
+}
+static void terminate_write(struct davinci_i2c_dev *dev)
+{
+	u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
+	w |= DAVINCI_I2C_MDR_RM | DAVINCI_I2C_MDR_STP;
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
+
+	if (!dev->terminate)
+		dev_dbg(dev->dev, "TDR IRQ while no data to send\n");
+}
+
+/*
+ * Interrupt service routine. This gets called whenever an I2C interrupt
+ * occurs.
+ */
+static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
+{
+	struct davinci_i2c_dev *dev = dev_id;
+	u32 stat;
+	int count = 0;
+	u16 w;
+
+	if (pm_runtime_suspended(dev->dev))
+		return IRQ_NONE;
+
+	while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) {
+		dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
+		if (count++ == 100) {
+			dev_warn(dev->dev, "Too much work in one IRQ\n");
+			break;
+		}
+
+		switch (stat) {
+		case DAVINCI_I2C_IVR_AL:
+			/* Arbitration lost, must retry */
+			dev->cmd_err |= DAVINCI_I2C_STR_AL;
+			dev->buf_len = 0;
+			complete(&dev->cmd_complete);
+			break;
+
+		case DAVINCI_I2C_IVR_NACK:
+			dev->cmd_err |= DAVINCI_I2C_STR_NACK;
+			dev->buf_len = 0;
+			complete(&dev->cmd_complete);
+			break;
+
+		case DAVINCI_I2C_IVR_ARDY:
+			davinci_i2c_write_reg(dev,
+				DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY);
+			if (((dev->buf_len == 0) && (dev->stop != 0)) ||
+			    (dev->cmd_err & DAVINCI_I2C_STR_NACK)) {
+				w = davinci_i2c_read_reg(dev,
+							 DAVINCI_I2C_MDR_REG);
+				w |= DAVINCI_I2C_MDR_STP;
+				davinci_i2c_write_reg(dev,
+						      DAVINCI_I2C_MDR_REG, w);
+			}
+			complete(&dev->cmd_complete);
+			break;
+
+		case DAVINCI_I2C_IVR_RDR:
+			if (dev->buf_len) {
+				*dev->buf++ =
+				    davinci_i2c_read_reg(dev,
+							 DAVINCI_I2C_DRR_REG);
+				dev->buf_len--;
+				if (dev->buf_len)
+					continue;
+
+				davinci_i2c_write_reg(dev,
+					DAVINCI_I2C_STR_REG,
+					DAVINCI_I2C_IMR_RRDY);
+			} else {
+				/* signal can terminate transfer */
+				terminate_read(dev);
+			}
+			break;
+
+		case DAVINCI_I2C_IVR_XRDY:
+			if (dev->buf_len) {
+				davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG,
+						      *dev->buf++);
+				dev->buf_len--;
+				if (dev->buf_len)
+					continue;
+
+				w = davinci_i2c_read_reg(dev,
+							 DAVINCI_I2C_IMR_REG);
+				w &= ~DAVINCI_I2C_IMR_XRDY;
+				davinci_i2c_write_reg(dev,
+						      DAVINCI_I2C_IMR_REG,
+						      w);
+			} else {
+				/* signal can terminate transfer */
+				terminate_write(dev);
+			}
+			break;
+
+		case DAVINCI_I2C_IVR_SCD:
+			davinci_i2c_write_reg(dev,
+				DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_SCD);
+			complete(&dev->cmd_complete);
+			break;
+
+		case DAVINCI_I2C_IVR_AAS:
+			dev_dbg(dev->dev, "Address as slave interrupt\n");
+			break;
+
+		default:
+			dev_warn(dev->dev, "Unrecognized irq stat %d\n", stat);
+			break;
+		}
+	}
+
+	return count ? IRQ_HANDLED : IRQ_NONE;
+}
+
+#ifdef CONFIG_CPU_FREQ
+static int i2c_davinci_cpufreq_transition(struct notifier_block *nb,
+				     unsigned long val, void *data)
+{
+	struct davinci_i2c_dev *dev;
+
+	dev = container_of(nb, struct davinci_i2c_dev, freq_transition);
+
+	i2c_lock_bus(&dev->adapter, I2C_LOCK_ROOT_ADAPTER);
+	if (val == CPUFREQ_PRECHANGE) {
+		davinci_i2c_reset_ctrl(dev, 0);
+	} else if (val == CPUFREQ_POSTCHANGE) {
+		i2c_davinci_calc_clk_dividers(dev);
+		davinci_i2c_reset_ctrl(dev, 1);
+	}
+	i2c_unlock_bus(&dev->adapter, I2C_LOCK_ROOT_ADAPTER);
+
+	return 0;
+}
+
+static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
+{
+	dev->freq_transition.notifier_call = i2c_davinci_cpufreq_transition;
+
+	return cpufreq_register_notifier(&dev->freq_transition,
+					 CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
+{
+	cpufreq_unregister_notifier(&dev->freq_transition,
+				    CPUFREQ_TRANSITION_NOTIFIER);
+}
+#else
+static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
+{
+	return 0;
+}
+
+static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
+{
+}
+#endif
+
+static const struct i2c_algorithm i2c_davinci_algo = {
+	.master_xfer	= i2c_davinci_xfer,
+	.functionality	= i2c_davinci_func,
+};
+
+static const struct of_device_id davinci_i2c_of_match[] = {
+	{.compatible = "ti,davinci-i2c", },
+	{.compatible = "ti,keystone-i2c", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, davinci_i2c_of_match);
+
+static int davinci_i2c_probe(struct platform_device *pdev)
+{
+	struct davinci_i2c_dev *dev;
+	struct i2c_adapter *adap;
+	struct resource *mem;
+	struct i2c_bus_recovery_info *rinfo;
+	int r, irq;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		if (!irq)
+			irq = -ENXIO;
+		if (irq != -EPROBE_DEFER)
+			dev_err(&pdev->dev,
+				"can't get irq resource ret=%d\n", irq);
+		return irq;
+	}
+
+	dev = devm_kzalloc(&pdev->dev, sizeof(struct davinci_i2c_dev),
+			GFP_KERNEL);
+	if (!dev) {
+		dev_err(&pdev->dev, "Memory allocation failed\n");
+		return -ENOMEM;
+	}
+
+	init_completion(&dev->cmd_complete);
+
+	dev->dev = &pdev->dev;
+	dev->irq = irq;
+	dev->pdata = dev_get_platdata(&pdev->dev);
+	platform_set_drvdata(pdev, dev);
+
+	if (!dev->pdata && pdev->dev.of_node) {
+		u32 prop;
+
+		dev->pdata = devm_kzalloc(&pdev->dev,
+			sizeof(struct davinci_i2c_platform_data), GFP_KERNEL);
+		if (!dev->pdata)
+			return -ENOMEM;
+
+		memcpy(dev->pdata, &davinci_i2c_platform_data_default,
+			sizeof(struct davinci_i2c_platform_data));
+		if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency",
+			&prop))
+			dev->pdata->bus_freq = prop / 1000;
+
+		dev->pdata->has_pfunc =
+			of_property_read_bool(pdev->dev.of_node,
+					      "ti,has-pfunc");
+	} else if (!dev->pdata) {
+		dev->pdata = &davinci_i2c_platform_data_default;
+	}
+
+	dev->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(dev->clk))
+		return PTR_ERR(dev->clk);
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dev->base = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(dev->base)) {
+		return PTR_ERR(dev->base);
+	}
+
+	pm_runtime_set_autosuspend_delay(dev->dev,
+					 DAVINCI_I2C_PM_TIMEOUT);
+	pm_runtime_use_autosuspend(dev->dev);
+
+	pm_runtime_enable(dev->dev);
+
+	r = pm_runtime_get_sync(dev->dev);
+	if (r < 0) {
+		dev_err(dev->dev, "failed to runtime_get device: %d\n", r);
+		pm_runtime_put_noidle(dev->dev);
+		return r;
+	}
+
+	i2c_davinci_init(dev);
+
+	r = devm_request_irq(&pdev->dev, dev->irq, i2c_davinci_isr, 0,
+			pdev->name, dev);
+	if (r) {
+		dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
+		goto err_unuse_clocks;
+	}
+
+	r = i2c_davinci_cpufreq_register(dev);
+	if (r) {
+		dev_err(&pdev->dev, "failed to register cpufreq\n");
+		goto err_unuse_clocks;
+	}
+
+	adap = &dev->adapter;
+	i2c_set_adapdata(adap, dev);
+	adap->owner = THIS_MODULE;
+	adap->class = I2C_CLASS_DEPRECATED;
+	strlcpy(adap->name, "DaVinci I2C adapter", sizeof(adap->name));
+	adap->algo = &i2c_davinci_algo;
+	adap->dev.parent = &pdev->dev;
+	adap->timeout = DAVINCI_I2C_TIMEOUT;
+	adap->dev.of_node = pdev->dev.of_node;
+
+	if (dev->pdata->has_pfunc)
+		adap->bus_recovery_info = &davinci_i2c_scl_recovery_info;
+	else if (dev->pdata->gpio_recovery) {
+		rinfo =  &davinci_i2c_gpio_recovery_info;
+		adap->bus_recovery_info = rinfo;
+		rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl",
+						  GPIOD_OUT_HIGH_OPEN_DRAIN);
+		if (IS_ERR(rinfo->scl_gpiod)) {
+			r = PTR_ERR(rinfo->scl_gpiod);
+			goto err_unuse_clocks;
+		}
+		rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN);
+		if (IS_ERR(rinfo->sda_gpiod)) {
+			r = PTR_ERR(rinfo->sda_gpiod);
+			goto err_unuse_clocks;
+		}
+	}
+
+	adap->nr = pdev->id;
+	r = i2c_add_numbered_adapter(adap);
+	if (r)
+		goto err_unuse_clocks;
+
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
+
+	return 0;
+
+err_unuse_clocks:
+	pm_runtime_dont_use_autosuspend(dev->dev);
+	pm_runtime_put_sync(dev->dev);
+	pm_runtime_disable(dev->dev);
+
+	return r;
+}
+
+static int davinci_i2c_remove(struct platform_device *pdev)
+{
+	struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
+	int ret;
+
+	i2c_davinci_cpufreq_deregister(dev);
+
+	i2c_del_adapter(&dev->adapter);
+
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&pdev->dev);
+		return ret;
+	}
+
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0);
+
+	pm_runtime_dont_use_autosuspend(dev->dev);
+	pm_runtime_put_sync(dev->dev);
+	pm_runtime_disable(dev->dev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int davinci_i2c_suspend(struct device *dev)
+{
+	struct davinci_i2c_dev *i2c_dev = dev_get_drvdata(dev);
+
+	/* put I2C into reset */
+	davinci_i2c_reset_ctrl(i2c_dev, 0);
+
+	return 0;
+}
+
+static int davinci_i2c_resume(struct device *dev)
+{
+	struct davinci_i2c_dev *i2c_dev = dev_get_drvdata(dev);
+
+	/* take I2C out of reset */
+	davinci_i2c_reset_ctrl(i2c_dev, 1);
+
+	return 0;
+}
+
+static const struct dev_pm_ops davinci_i2c_pm = {
+	.suspend        = davinci_i2c_suspend,
+	.resume         = davinci_i2c_resume,
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				      pm_runtime_force_resume)
+};
+
+#define davinci_i2c_pm_ops (&davinci_i2c_pm)
+#else
+#define davinci_i2c_pm_ops NULL
+#endif
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:i2c_davinci");
+
+static struct platform_driver davinci_i2c_driver = {
+	.probe		= davinci_i2c_probe,
+	.remove		= davinci_i2c_remove,
+	.driver		= {
+		.name	= "i2c_davinci",
+		.pm	= davinci_i2c_pm_ops,
+		.of_match_table = davinci_i2c_of_match,
+	},
+};
+
+/* I2C may be needed to bring up other drivers */
+static int __init davinci_i2c_init_driver(void)
+{
+	return platform_driver_register(&davinci_i2c_driver);
+}
+subsys_initcall(davinci_i2c_init_driver);
+
+static void __exit davinci_i2c_exit_driver(void)
+{
+	platform_driver_unregister(&davinci_i2c_driver);
+}
+module_exit(davinci_i2c_exit_driver);
+
+MODULE_AUTHOR("Texas Instruments India");
+MODULE_DESCRIPTION("TI DaVinci I2C bus adapter");
+MODULE_LICENSE("GPL");