i2c: remove u300 bus driver

The ST-Ericsson U300 platform is getting removed, so this driver is no
longer needed.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

3 files changed, 0 insertions, 1022 deletions

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index ce2efb56df54..4fe74259d44c 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1032,19 +1032,6 @@ config I2C_STM32F7
 	  This driver can also be built as module. If so, the module
 	  will be called i2c-stm32f7.
 
-config I2C_STU300
-	tristate "ST Microelectronics DDC I2C interface"
-	depends on MACH_U300 || COMPILE_TEST
-	default y if MACH_U300
-	help
-	  If you say yes to this option, support will be included for the
-	  I2C interface from ST Microelectronics simply called "DDC I2C"
-	  supporting both I2C and DDC, used in e.g. the U300 series
-	  mobile platforms.
-
-	  This driver can also be built as a module. If so, the module
-	  will be called i2c-stu300.
-
 config I2C_SUN6I_P2WI
 	tristate "Allwinner sun6i internal P2WI controller"
 	depends on RESET_CONTROLLER
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 1c30bba977ef..572d5fcc6016 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -103,7 +103,6 @@ obj-$(CONFIG_I2C_ST)		+= i2c-st.o
 obj-$(CONFIG_I2C_STM32F4)	+= i2c-stm32f4.o
 i2c-stm32f7-drv-objs := i2c-stm32f7.o i2c-stm32.o
 obj-$(CONFIG_I2C_STM32F7)	+= i2c-stm32f7-drv.o
-obj-$(CONFIG_I2C_STU300)	+= i2c-stu300.o
 obj-$(CONFIG_I2C_SUN6I_P2WI)	+= i2c-sun6i-p2wi.o
 obj-$(CONFIG_I2C_SYNQUACER)	+= i2c-synquacer.o
 obj-$(CONFIG_I2C_TEGRA)		+= i2c-tegra.o
diff --git a/drivers/i2c/busses/i2c-stu300.c b/drivers/i2c/busses/i2c-stu300.c
deleted file mode 100644
index 64d739baf480..000000000000
--- a/drivers/i2c/busses/i2c-stu300.c
+++ /dev/null
@@ -1,1008 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2007-2012 ST-Ericsson AB
- * ST DDC I2C master mode driver, used in e.g. U300 series platforms.
- * Author: Linus Walleij <linus.walleij@stericsson.com>
- * Author: Jonas Aaberg <jonas.aberg@stericsson.com>
- */
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/delay.h>
-#include <linux/i2c.h>
-#include <linux/spinlock.h>
-#include <linux/completion.h>
-#include <linux/err.h>
-#include <linux/interrupt.h>
-#include <linux/clk.h>
-#include <linux/io.h>
-#include <linux/slab.h>
-
-/* the name of this kernel module */
-#define NAME "stu300"
-
-/* CR (Control Register) 8bit (R/W) */
-#define I2C_CR					(0x00000000)
-#define I2C_CR_RESET_VALUE			(0x00)
-#define I2C_CR_RESET_UMASK			(0x00)
-#define I2C_CR_DDC1_ENABLE			(0x80)
-#define I2C_CR_TRANS_ENABLE			(0x40)
-#define I2C_CR_PERIPHERAL_ENABLE		(0x20)
-#define I2C_CR_DDC2B_ENABLE			(0x10)
-#define I2C_CR_START_ENABLE			(0x08)
-#define I2C_CR_ACK_ENABLE			(0x04)
-#define I2C_CR_STOP_ENABLE			(0x02)
-#define I2C_CR_INTERRUPT_ENABLE			(0x01)
-/* SR1 (Status Register 1) 8bit (R/-) */
-#define I2C_SR1					(0x00000004)
-#define I2C_SR1_RESET_VALUE			(0x00)
-#define I2C_SR1_RESET_UMASK			(0x00)
-#define I2C_SR1_EVF_IND				(0x80)
-#define I2C_SR1_ADD10_IND			(0x40)
-#define I2C_SR1_TRA_IND				(0x20)
-#define I2C_SR1_BUSY_IND			(0x10)
-#define I2C_SR1_BTF_IND				(0x08)
-#define I2C_SR1_ADSL_IND			(0x04)
-#define I2C_SR1_MSL_IND				(0x02)
-#define I2C_SR1_SB_IND				(0x01)
-/* SR2 (Status Register 2) 8bit (R/-) */
-#define I2C_SR2					(0x00000008)
-#define I2C_SR2_RESET_VALUE			(0x00)
-#define I2C_SR2_RESET_UMASK			(0x40)
-#define I2C_SR2_MASK				(0xBF)
-#define I2C_SR2_SCLFAL_IND			(0x80)
-#define I2C_SR2_ENDAD_IND			(0x20)
-#define I2C_SR2_AF_IND				(0x10)
-#define I2C_SR2_STOPF_IND			(0x08)
-#define I2C_SR2_ARLO_IND			(0x04)
-#define I2C_SR2_BERR_IND			(0x02)
-#define I2C_SR2_DDC2BF_IND			(0x01)
-/* CCR (Clock Control Register) 8bit (R/W) */
-#define I2C_CCR					(0x0000000C)
-#define I2C_CCR_RESET_VALUE			(0x00)
-#define I2C_CCR_RESET_UMASK			(0x00)
-#define I2C_CCR_MASK				(0xFF)
-#define I2C_CCR_FMSM				(0x80)
-#define I2C_CCR_CC_MASK				(0x7F)
-/* OAR1 (Own Address Register 1) 8bit (R/W) */
-#define I2C_OAR1				(0x00000010)
-#define I2C_OAR1_RESET_VALUE			(0x00)
-#define I2C_OAR1_RESET_UMASK			(0x00)
-#define I2C_OAR1_ADD_MASK			(0xFF)
-/* OAR2 (Own Address Register 2) 8bit (R/W) */
-#define I2C_OAR2				(0x00000014)
-#define I2C_OAR2_RESET_VALUE			(0x40)
-#define I2C_OAR2_RESET_UMASK			(0x19)
-#define I2C_OAR2_MASK				(0xE6)
-#define I2C_OAR2_FR_25_10MHZ			(0x00)
-#define I2C_OAR2_FR_10_1667MHZ			(0x20)
-#define I2C_OAR2_FR_1667_2667MHZ		(0x40)
-#define I2C_OAR2_FR_2667_40MHZ			(0x60)
-#define I2C_OAR2_FR_40_5333MHZ			(0x80)
-#define I2C_OAR2_FR_5333_66MHZ			(0xA0)
-#define I2C_OAR2_FR_66_80MHZ			(0xC0)
-#define I2C_OAR2_FR_80_100MHZ			(0xE0)
-#define I2C_OAR2_FR_MASK			(0xE0)
-#define I2C_OAR2_ADD_MASK			(0x06)
-/* DR (Data Register) 8bit (R/W) */
-#define I2C_DR					(0x00000018)
-#define I2C_DR_RESET_VALUE			(0x00)
-#define I2C_DR_RESET_UMASK			(0xFF)
-#define I2C_DR_D_MASK				(0xFF)
-/* ECCR (Extended Clock Control Register) 8bit (R/W) */
-#define I2C_ECCR				(0x0000001C)
-#define I2C_ECCR_RESET_VALUE			(0x00)
-#define I2C_ECCR_RESET_UMASK			(0xE0)
-#define I2C_ECCR_MASK				(0x1F)
-#define I2C_ECCR_CC_MASK			(0x1F)
-
-/*
- * These events are more or less responses to commands
- * sent into the hardware, presumably reflecting the state
- * of an internal state machine.
- */
-enum stu300_event {
-	STU300_EVENT_NONE = 0,
-	STU300_EVENT_1,
-	STU300_EVENT_2,
-	STU300_EVENT_3,
-	STU300_EVENT_4,
-	STU300_EVENT_5,
-	STU300_EVENT_6,
-	STU300_EVENT_7,
-	STU300_EVENT_8,
-	STU300_EVENT_9
-};
-
-enum stu300_error {
-	STU300_ERROR_NONE = 0,
-	STU300_ERROR_ACKNOWLEDGE_FAILURE,
-	STU300_ERROR_BUS_ERROR,
-	STU300_ERROR_ARBITRATION_LOST,
-	STU300_ERROR_UNKNOWN
-};
-
-/* timeout waiting for the controller to respond */
-#define STU300_TIMEOUT (msecs_to_jiffies(1000))
-
-/*
- * The number of address send athemps tried before giving up.
- * If the first one fails it seems like 5 to 8 attempts are required.
- */
-#define NUM_ADDR_RESEND_ATTEMPTS 12
-
-/* I2C clock speed, in Hz 0-400kHz*/
-static unsigned int scl_frequency = I2C_MAX_STANDARD_MODE_FREQ;
-module_param(scl_frequency, uint,  0644);
-
-/**
- * struct stu300_dev - the stu300 driver state holder
- * @pdev: parent platform device
- * @adapter: corresponding I2C adapter
- * @clk: hardware block clock
- * @irq: assigned interrupt line
- * @cmd_issue_lock: this locks the following cmd_ variables
- * @cmd_complete: acknowledge completion for an I2C command
- * @cmd_event: expected event coming in as a response to a command
- * @cmd_err: error code as response to a command
- * @speed: current bus speed in Hz
- * @msg_index: index of current message
- * @msg_len: length of current message
- */
-
-struct stu300_dev {
-	struct platform_device	*pdev;
-	struct i2c_adapter	adapter;
-	void __iomem		*virtbase;
-	struct clk		*clk;
-	int			irq;
-	spinlock_t		cmd_issue_lock;
-	struct completion	cmd_complete;
-	enum stu300_event	cmd_event;
-	enum stu300_error	cmd_err;
-	unsigned int		speed;
-	int			msg_index;
-	int			msg_len;
-};
-
-/* Local forward function declarations */
-static int stu300_init_hw(struct stu300_dev *dev);
-
-/*
- * The block needs writes in both MSW and LSW in order
- * for all data lines to reach their destination.
- */
-static inline void stu300_wr8(u32 value, void __iomem *address)
-{
-	writel((value << 16) | value, address);
-}
-
-/*
- * This merely masks off the duplicates which appear
- * in bytes 1-3. You _MUST_ use 32-bit bus access on this
- * device, else it will not work.
- */
-static inline u32 stu300_r8(void __iomem *address)
-{
-	return readl(address) & 0x000000FFU;
-}
-
-static void stu300_irq_enable(struct stu300_dev *dev)
-{
-	u32 val;
-	val = stu300_r8(dev->virtbase + I2C_CR);
-	val |= I2C_CR_INTERRUPT_ENABLE;
-	/* Twice paranoia (possible HW glitch) */
-	stu300_wr8(val, dev->virtbase + I2C_CR);
-	stu300_wr8(val, dev->virtbase + I2C_CR);
-}
-
-static void stu300_irq_disable(struct stu300_dev *dev)
-{
-	u32 val;
-	val = stu300_r8(dev->virtbase + I2C_CR);
-	val &= ~I2C_CR_INTERRUPT_ENABLE;
-	/* Twice paranoia (possible HW glitch) */
-	stu300_wr8(val, dev->virtbase + I2C_CR);
-	stu300_wr8(val, dev->virtbase + I2C_CR);
-}
-
-
-/*
- * Tells whether a certain event or events occurred in
- * response to a command. The events represent states in
- * the internal state machine of the hardware. The events
- * are not very well described in the hardware
- * documentation and can only be treated as abstract state
- * machine states.
- *
- * @ret 0 = event has not occurred or unknown error, any
- * other value means the correct event occurred or an error.
- */
-
-static int stu300_event_occurred(struct stu300_dev *dev,
-				   enum stu300_event mr_event) {
-	u32 status1;
-	u32 status2;
-
-	/* What event happened? */
-	status1 = stu300_r8(dev->virtbase + I2C_SR1);
-
-	if (!(status1 & I2C_SR1_EVF_IND))
-		/* No event at all */
-		return 0;
-
-	status2 = stu300_r8(dev->virtbase + I2C_SR2);
-
-	/* Block any multiple interrupts */
-	stu300_irq_disable(dev);
-
-	/* Check for errors first */
-	if (status2 & I2C_SR2_AF_IND) {
-		dev->cmd_err = STU300_ERROR_ACKNOWLEDGE_FAILURE;
-		return 1;
-	} else if (status2 & I2C_SR2_BERR_IND) {
-		dev->cmd_err = STU300_ERROR_BUS_ERROR;
-		return 1;
-	} else if (status2 & I2C_SR2_ARLO_IND) {
-		dev->cmd_err = STU300_ERROR_ARBITRATION_LOST;
-		return 1;
-	}
-
-	switch (mr_event) {
-	case STU300_EVENT_1:
-		if (status1 & I2C_SR1_ADSL_IND)
-			return 1;
-		break;
-	case STU300_EVENT_2:
-	case STU300_EVENT_3:
-	case STU300_EVENT_7:
-	case STU300_EVENT_8:
-		if (status1 & I2C_SR1_BTF_IND) {
-			return 1;
-		}
-		break;
-	case STU300_EVENT_4:
-		if (status2 & I2C_SR2_STOPF_IND)
-			return 1;
-		break;
-	case STU300_EVENT_5:
-		if (status1 & I2C_SR1_SB_IND)
-			/* Clear start bit */
-			return 1;
-		break;
-	case STU300_EVENT_6:
-		if (status2 & I2C_SR2_ENDAD_IND) {
-			/* First check for any errors */
-			return 1;
-		}
-		break;
-	case STU300_EVENT_9:
-		if (status1 & I2C_SR1_ADD10_IND)
-			return 1;
-		break;
-	default:
-		break;
-	}
-	/* If we get here, we're on thin ice.
-	 * Here we are in a status where we have
-	 * gotten a response that does not match
-	 * what we requested.
-	 */
-	dev->cmd_err = STU300_ERROR_UNKNOWN;
-	dev_err(&dev->pdev->dev,
-		"Unhandled interrupt! %d sr1: 0x%x sr2: 0x%x\n",
-		mr_event, status1, status2);
-	return 0;
-}
-
-static irqreturn_t stu300_irh(int irq, void *data)
-{
-	struct stu300_dev *dev = data;
-	int res;
-
-	/* Just make sure that the block is clocked */
-	clk_enable(dev->clk);
-
-	/* See if this was what we were waiting for */
-	spin_lock(&dev->cmd_issue_lock);
-
-	res = stu300_event_occurred(dev, dev->cmd_event);
-	if (res || dev->cmd_err != STU300_ERROR_NONE)
-		complete(&dev->cmd_complete);
-
-	spin_unlock(&dev->cmd_issue_lock);
-
-	clk_disable(dev->clk);
-
-	return IRQ_HANDLED;
-}
-
-/*
- * Sends a command and then waits for the bits masked by *flagmask*
- * to go high or low by IRQ awaiting.
- */
-static int stu300_start_and_await_event(struct stu300_dev *dev,
-					  u8 cr_value,
-					  enum stu300_event mr_event)
-{
-	int ret;
-
-	/* Lock command issue, fill in an event we wait for */
-	spin_lock_irq(&dev->cmd_issue_lock);
-	init_completion(&dev->cmd_complete);
-	dev->cmd_err = STU300_ERROR_NONE;
-	dev->cmd_event = mr_event;
-	spin_unlock_irq(&dev->cmd_issue_lock);
-
-	/* Turn on interrupt, send command and wait. */
-	cr_value |= I2C_CR_INTERRUPT_ENABLE;
-	stu300_wr8(cr_value, dev->virtbase + I2C_CR);
-	ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
-							STU300_TIMEOUT);
-	if (ret < 0) {
-		dev_err(&dev->pdev->dev,
-		       "wait_for_completion_interruptible_timeout() "
-		       "returned %d waiting for event %04x\n", ret, mr_event);
-		return ret;
-	}
-
-	if (ret == 0) {
-		dev_err(&dev->pdev->dev, "controller timed out "
-		       "waiting for event %d, reinit hardware\n", mr_event);
-		(void) stu300_init_hw(dev);
-		return -ETIMEDOUT;
-	}
-
-	if (dev->cmd_err != STU300_ERROR_NONE) {
-		dev_err(&dev->pdev->dev, "controller (start) "
-		       "error %d waiting for event %d, reinit hardware\n",
-		       dev->cmd_err, mr_event);
-		(void) stu300_init_hw(dev);
-		return -EIO;
-	}
-
-	return 0;
-}
-
-/*
- * This waits for a flag to be set, if it is not set on entry, an interrupt is
- * configured to wait for the flag using a completion.
- */
-static int stu300_await_event(struct stu300_dev *dev,
-				enum stu300_event mr_event)
-{
-	int ret;
-
-	/* Is it already here? */
-	spin_lock_irq(&dev->cmd_issue_lock);
-	dev->cmd_err = STU300_ERROR_NONE;
-	dev->cmd_event = mr_event;
-
-	init_completion(&dev->cmd_complete);
-
-	/* Turn on the I2C interrupt for current operation */
-	stu300_irq_enable(dev);
-
-	/* Unlock the command block and wait for the event to occur */
-	spin_unlock_irq(&dev->cmd_issue_lock);
-
-	ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
-							STU300_TIMEOUT);
-	if (ret < 0) {
-		dev_err(&dev->pdev->dev,
-		       "wait_for_completion_interruptible_timeout()"
-		       "returned %d waiting for event %04x\n", ret, mr_event);
-		return ret;
-	}
-
-	if (ret == 0) {
-		if (mr_event != STU300_EVENT_6) {
-			dev_err(&dev->pdev->dev, "controller "
-				"timed out waiting for event %d, reinit "
-				"hardware\n", mr_event);
-			(void) stu300_init_hw(dev);
-		}
-		return -ETIMEDOUT;
-	}
-
-	if (dev->cmd_err != STU300_ERROR_NONE) {
-		if (mr_event != STU300_EVENT_6) {
-			dev_err(&dev->pdev->dev, "controller "
-				"error (await_event) %d waiting for event %d, "
-			       "reinit hardware\n", dev->cmd_err, mr_event);
-			(void) stu300_init_hw(dev);
-		}
-		return -EIO;
-	}
-
-	return 0;
-}
-
-/*
- * Waits for the busy bit to go low by repeated polling.
- */
-#define BUSY_RELEASE_ATTEMPTS 10
-static int stu300_wait_while_busy(struct stu300_dev *dev)
-{
-	unsigned long timeout;
-	int i;
-
-	for (i = 0; i < BUSY_RELEASE_ATTEMPTS; i++) {
-		timeout = jiffies + STU300_TIMEOUT;
-
-		while (!time_after(jiffies, timeout)) {
-			/* Is not busy? */
-			if ((stu300_r8(dev->virtbase + I2C_SR1) &
-			     I2C_SR1_BUSY_IND) == 0)
-				return 0;
-			msleep(1);
-		}
-
-		dev_err(&dev->pdev->dev, "transaction timed out "
-			"waiting for device to be free (not busy). "
-		       "Attempt: %d\n", i+1);
-
-		dev_err(&dev->pdev->dev, "base address = "
-			"0x%p, reinit hardware\n", dev->virtbase);
-
-		(void) stu300_init_hw(dev);
-	}
-
-	dev_err(&dev->pdev->dev, "giving up after %d attempts "
-		"to reset the bus.\n",  BUSY_RELEASE_ATTEMPTS);
-
-	return -ETIMEDOUT;
-}
-
-struct stu300_clkset {
-	unsigned long rate;
-	u32 setting;
-};
-
-static const struct stu300_clkset stu300_clktable[] = {
-	{ 0,         0xFFU },
-	{ 2500000,   I2C_OAR2_FR_25_10MHZ },
-	{ 10000000,  I2C_OAR2_FR_10_1667MHZ },
-	{ 16670000,  I2C_OAR2_FR_1667_2667MHZ },
-	{ 26670000,  I2C_OAR2_FR_2667_40MHZ },
-	{ 40000000,  I2C_OAR2_FR_40_5333MHZ },
-	{ 53330000,  I2C_OAR2_FR_5333_66MHZ },
-	{ 66000000,  I2C_OAR2_FR_66_80MHZ },
-	{ 80000000,  I2C_OAR2_FR_80_100MHZ },
-	{ 100000000, 0xFFU },
-};
-
-
-static int stu300_set_clk(struct stu300_dev *dev, unsigned long clkrate)
-{
-
-	u32 val;
-	int i = 0;
-
-	/* Locate the appropriate clock setting */
-	while (i < ARRAY_SIZE(stu300_clktable) - 1 &&
-	       stu300_clktable[i].rate < clkrate)
-		i++;
-
-	if (stu300_clktable[i].setting == 0xFFU) {
-		dev_err(&dev->pdev->dev, "too %s clock rate requested "
-			"(%lu Hz).\n", i ? "high" : "low", clkrate);
-		return -EINVAL;
-	}
-
-	stu300_wr8(stu300_clktable[i].setting,
-		   dev->virtbase + I2C_OAR2);
-
-	dev_dbg(&dev->pdev->dev, "Clock rate %lu Hz, I2C bus speed %d Hz "
-		"virtbase %p\n", clkrate, dev->speed, dev->virtbase);
-
-	if (dev->speed > I2C_MAX_STANDARD_MODE_FREQ)
-		/* Fast Mode I2C */
-		val = ((clkrate/dev->speed) - 9)/3 + 1;
-	else
-		/* Standard Mode I2C */
-		val = ((clkrate/dev->speed) - 7)/2 + 1;
-
-	/* According to spec the divider must be > 2 */
-	if (val < 0x002) {
-		dev_err(&dev->pdev->dev, "too low clock rate (%lu Hz).\n",
-			clkrate);
-		return -EINVAL;
-	}
-
-	/* We have 12 bits clock divider only! */
-	if (val & 0xFFFFF000U) {
-		dev_err(&dev->pdev->dev, "too high clock rate (%lu Hz).\n",
-			clkrate);
-		return -EINVAL;
-	}
-
-	if (dev->speed > I2C_MAX_STANDARD_MODE_FREQ) {
-		/* CC6..CC0 */
-		stu300_wr8((val & I2C_CCR_CC_MASK) | I2C_CCR_FMSM,
-			   dev->virtbase + I2C_CCR);
-		dev_dbg(&dev->pdev->dev, "set clock divider to 0x%08x, "
-			"Fast Mode I2C\n", val);
-	} else {
-		/* CC6..CC0 */
-		stu300_wr8((val & I2C_CCR_CC_MASK),
-			   dev->virtbase + I2C_CCR);
-		dev_dbg(&dev->pdev->dev, "set clock divider to "
-			"0x%08x, Standard Mode I2C\n", val);
-	}
-
-	/* CC11..CC7 */
-	stu300_wr8(((val >> 7) & 0x1F),
-		   dev->virtbase + I2C_ECCR);
-
-	return 0;
-}
-
-
-static int stu300_init_hw(struct stu300_dev *dev)
-{
-	u32 dummy;
-	unsigned long clkrate;
-	int ret;
-
-	/* Disable controller */
-	stu300_wr8(0x00, dev->virtbase + I2C_CR);
-	/*
-	 * Set own address to some default value (0x00).
-	 * We do not support slave mode anyway.
-	 */
-	stu300_wr8(0x00, dev->virtbase + I2C_OAR1);
-	/*
-	 * The I2C controller only operates properly in 26 MHz but we
-	 * program this driver as if we didn't know. This will also set the two
-	 * high bits of the own address to zero as well.
-	 * There is no known hardware issue with running in 13 MHz
-	 * However, speeds over 200 kHz are not used.
-	 */
-	clkrate = clk_get_rate(dev->clk);
-	ret = stu300_set_clk(dev, clkrate);
-
-	if (ret)
-		return ret;
-	/*
-	 * Enable block, do it TWICE (hardware glitch)
-	 * Setting bit 7 can enable DDC mode. (Not used currently.)
-	 */
-	stu300_wr8(I2C_CR_PERIPHERAL_ENABLE,
-				  dev->virtbase + I2C_CR);
-	stu300_wr8(I2C_CR_PERIPHERAL_ENABLE,
-				  dev->virtbase + I2C_CR);
-	/* Make a dummy read of the status register SR1 & SR2 */
-	dummy = stu300_r8(dev->virtbase + I2C_SR2);
-	dummy = stu300_r8(dev->virtbase + I2C_SR1);
-
-	return 0;
-}
-
-
-
-/* Send slave address. */
-static int stu300_send_address(struct stu300_dev *dev,
-				 struct i2c_msg *msg, int resend)
-{
-	u32 val;
-	int ret;
-
-	if (msg->flags & I2C_M_TEN) {
-		/* This is probably how 10 bit addresses look */
-		val = (0xf0 | (((u32) msg->addr & 0x300) >> 7)) &
-			I2C_DR_D_MASK;
-		if (msg->flags & I2C_M_RD)
-			/* This is the direction bit */
-			val |= 0x01;
-	} else {
-		val = i2c_8bit_addr_from_msg(msg);
-	}
-
-	if (resend) {
-		if (msg->flags & I2C_M_RD)
-			dev_dbg(&dev->pdev->dev, "read resend\n");
-		else
-			dev_dbg(&dev->pdev->dev, "write resend\n");
-	}
-
-	stu300_wr8(val, dev->virtbase + I2C_DR);
-
-	/* For 10bit addressing, await 10bit request (EVENT 9) */
-	if (msg->flags & I2C_M_TEN) {
-		ret = stu300_await_event(dev, STU300_EVENT_9);
-		/*
-		 * The slave device wants a 10bit address, send the rest
-		 * of the bits (the LSBits)
-		 */
-		val = msg->addr & I2C_DR_D_MASK;
-		/* This clears "event 9" */
-		stu300_wr8(val, dev->virtbase + I2C_DR);
-		if (ret != 0)
-			return ret;
-	}
-	/* FIXME: Why no else here? two events for 10bit?
-	 * Await event 6 (normal) or event 9 (10bit)
-	 */
-
-	if (resend)
-		dev_dbg(&dev->pdev->dev, "await event 6\n");
-	ret = stu300_await_event(dev, STU300_EVENT_6);
-
-	/*
-	 * Clear any pending EVENT 6 no matter what happened during
-	 * await_event.
-	 */
-	val = stu300_r8(dev->virtbase + I2C_CR);
-	val |= I2C_CR_PERIPHERAL_ENABLE;
-	stu300_wr8(val, dev->virtbase + I2C_CR);
-
-	return ret;
-}
-
-static int stu300_xfer_msg(struct i2c_adapter *adap,
-			     struct i2c_msg *msg, int stop)
-{
-	u32 cr;
-	u32 val;
-	u32 i;
-	int ret;
-	int attempts = 0;
-	struct stu300_dev *dev = i2c_get_adapdata(adap);
-
-	clk_enable(dev->clk);
-
-	/* Remove this if (0) to trace each and every message. */
-	if (0) {
-		dev_dbg(&dev->pdev->dev, "I2C message to: 0x%04x, len: %d, "
-			"flags: 0x%04x, stop: %d\n",
-			msg->addr, msg->len, msg->flags, stop);
-	}
-
-	/*
-	 * For some reason, sending the address sometimes fails when running
-	 * on  the 13 MHz clock. No interrupt arrives. This is a work around,
-	 * which tries to restart and send the address up to 10 times before
-	 * really giving up. Usually 5 to 8 attempts are enough.
-	 */
-	do {
-		if (attempts)
-			dev_dbg(&dev->pdev->dev, "wait while busy\n");
-		/* Check that the bus is free, or wait until some timeout */
-		ret = stu300_wait_while_busy(dev);
-		if (ret != 0)
-			goto exit_disable;
-
-		if (attempts)
-			dev_dbg(&dev->pdev->dev, "re-int hw\n");
-		/*
-		 * According to ST, there is no problem if the clock is
-		 * changed between 13 and 26 MHz during a transfer.
-		 */
-		ret = stu300_init_hw(dev);
-		if (ret)
-			goto exit_disable;
-
-		/* Send a start condition */
-		cr = I2C_CR_PERIPHERAL_ENABLE;
-		/* Setting the START bit puts the block in master mode */
-		if (!(msg->flags & I2C_M_NOSTART))
-			cr |= I2C_CR_START_ENABLE;
-		if ((msg->flags & I2C_M_RD) && (msg->len > 1))
-			/* On read more than 1 byte, we need ack. */
-			cr |= I2C_CR_ACK_ENABLE;
-		/* Check that it gets through */
-		if (!(msg->flags & I2C_M_NOSTART)) {
-			if (attempts)
-				dev_dbg(&dev->pdev->dev, "send start event\n");
-			ret = stu300_start_and_await_event(dev, cr,
-							     STU300_EVENT_5);
-		}
-
-		if (attempts)
-			dev_dbg(&dev->pdev->dev, "send address\n");
-
-		if (ret == 0)
-			/* Send address */
-			ret = stu300_send_address(dev, msg, attempts != 0);
-
-		if (ret != 0) {
-			attempts++;
-			dev_dbg(&dev->pdev->dev, "failed sending address, "
-				"retrying. Attempt: %d msg_index: %d/%d\n",
-			       attempts, dev->msg_index, dev->msg_len);
-		}
-
-	} while (ret != 0 && attempts < NUM_ADDR_RESEND_ATTEMPTS);
-
-	if (attempts < NUM_ADDR_RESEND_ATTEMPTS && attempts > 0) {
-		dev_dbg(&dev->pdev->dev, "managed to get address "
-			"through after %d attempts\n", attempts);
-	} else if (attempts == NUM_ADDR_RESEND_ATTEMPTS) {
-		dev_dbg(&dev->pdev->dev, "I give up, tried %d times "
-			"to resend address.\n",
-			NUM_ADDR_RESEND_ATTEMPTS);
-		goto exit_disable;
-	}
-
-
-	if (msg->flags & I2C_M_RD) {
-		/* READ: we read the actual bytes one at a time */
-		for (i = 0; i < msg->len; i++) {
-			if (i == msg->len-1) {
-				/*
-				 * Disable ACK and set STOP condition before
-				 * reading last byte
-				 */
-				val = I2C_CR_PERIPHERAL_ENABLE;
-
-				if (stop)
-					val |= I2C_CR_STOP_ENABLE;
-
-				stu300_wr8(val,
-					   dev->virtbase + I2C_CR);
-			}
-			/* Wait for this byte... */
-			ret = stu300_await_event(dev, STU300_EVENT_7);
-			if (ret != 0)
-				goto exit_disable;
-			/* This clears event 7 */
-			msg->buf[i] = (u8) stu300_r8(dev->virtbase + I2C_DR);
-		}
-	} else {
-		/* WRITE: we send the actual bytes one at a time */
-		for (i = 0; i < msg->len; i++) {
-			/* Write the byte */
-			stu300_wr8(msg->buf[i],
-				   dev->virtbase + I2C_DR);
-			/* Check status */
-			ret = stu300_await_event(dev, STU300_EVENT_8);
-			/* Next write to DR will clear event 8 */
-			if (ret != 0) {
-				dev_err(&dev->pdev->dev, "error awaiting "
-				       "event 8 (%d)\n", ret);
-				goto exit_disable;
-			}
-		}
-		/* Check NAK */
-		if (!(msg->flags & I2C_M_IGNORE_NAK)) {
-			if (stu300_r8(dev->virtbase + I2C_SR2) &
-			    I2C_SR2_AF_IND) {
-				dev_err(&dev->pdev->dev, "I2C payload "
-				       "send returned NAK!\n");
-				ret = -EIO;
-				goto exit_disable;
-			}
-		}
-		if (stop) {
-			/* Send stop condition */
-			val = I2C_CR_PERIPHERAL_ENABLE;
-			val |= I2C_CR_STOP_ENABLE;
-			stu300_wr8(val, dev->virtbase + I2C_CR);
-		}
-	}
-
-	/* Check that the bus is free, or wait until some timeout occurs */
-	ret = stu300_wait_while_busy(dev);
-	if (ret != 0) {
-		dev_err(&dev->pdev->dev, "timeout waiting for transfer "
-		       "to commence.\n");
-		goto exit_disable;
-	}
-
-	/* Dummy read status registers */
-	val = stu300_r8(dev->virtbase + I2C_SR2);
-	val = stu300_r8(dev->virtbase + I2C_SR1);
-	ret = 0;
-
- exit_disable:
-	/* Disable controller */
-	stu300_wr8(0x00, dev->virtbase + I2C_CR);
-	clk_disable(dev->clk);
-	return ret;
-}
-
-static int stu300_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
-			 int num)
-{
-	int ret = -1;
-	int i;
-
-	struct stu300_dev *dev = i2c_get_adapdata(adap);
-	dev->msg_len = num;
-
-	for (i = 0; i < num; i++) {
-		/*
-		 * Another driver appears to send stop for each message,
-		 * here we only do that for the last message. Possibly some
-		 * peripherals require this behaviour, then their drivers
-		 * have to send single messages in order to get "stop" for
-		 * each message.
-		 */
-		dev->msg_index = i;
-
-		ret = stu300_xfer_msg(adap, &msgs[i], (i == (num - 1)));
-
-		if (ret != 0) {
-			num = ret;
-			break;
-		}
-	}
-
-	return num;
-}
-
-static int stu300_xfer_todo(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
-{
-	/* TODO: implement polling for this case if need be. */
-	WARN(1, "%s: atomic transfers not implemented\n", dev_name(&adap->dev));
-	return -EOPNOTSUPP;
-}
-
-static u32 stu300_func(struct i2c_adapter *adap)
-{
-	/* This is the simplest thing you can think of... */
-	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
-}
-
-static const struct i2c_algorithm stu300_algo = {
-	.master_xfer = stu300_xfer,
-	.master_xfer_atomic = stu300_xfer_todo,
-	.functionality = stu300_func,
-};
-
-static const struct i2c_adapter_quirks stu300_quirks = {
-	.flags = I2C_AQ_NO_ZERO_LEN,
-};
-
-static int stu300_probe(struct platform_device *pdev)
-{
-	struct stu300_dev *dev;
-	struct i2c_adapter *adap;
-	int bus_nr;
-	int ret = 0;
-
-	dev = devm_kzalloc(&pdev->dev, sizeof(struct stu300_dev), GFP_KERNEL);
-	if (!dev)
-		return -ENOMEM;
-
-	bus_nr = pdev->id;
-	dev->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(dev->clk)) {
-		dev_err(&pdev->dev, "could not retrieve i2c bus clock\n");
-		return PTR_ERR(dev->clk);
-	}
-
-	dev->pdev = pdev;
-	dev->virtbase = devm_platform_ioremap_resource(pdev, 0);
-	dev_dbg(&pdev->dev, "initialize bus device I2C%d on virtual "
-		"base %p\n", bus_nr, dev->virtbase);
-	if (IS_ERR(dev->virtbase))
-		return PTR_ERR(dev->virtbase);
-
-	dev->irq = platform_get_irq(pdev, 0);
-	ret = devm_request_irq(&pdev->dev, dev->irq, stu300_irh, 0, NAME, dev);
-	if (ret < 0)
-		return ret;
-
-	dev->speed = scl_frequency;
-
-	clk_prepare_enable(dev->clk);
-	ret = stu300_init_hw(dev);
-	clk_disable(dev->clk);
-	if (ret != 0) {
-		dev_err(&dev->pdev->dev, "error initializing hardware.\n");
-		return -EIO;
-	}
-
-	/* IRQ event handling initialization */
-	spin_lock_init(&dev->cmd_issue_lock);
-	dev->cmd_event = STU300_EVENT_NONE;
-	dev->cmd_err = STU300_ERROR_NONE;
-
-	adap = &dev->adapter;
-	adap->owner = THIS_MODULE;
-	/* DDC class but actually often used for more generic I2C */
-	adap->class = I2C_CLASS_DEPRECATED;
-	strlcpy(adap->name, "ST Microelectronics DDC I2C adapter",
-		sizeof(adap->name));
-	adap->nr = bus_nr;
-	adap->algo = &stu300_algo;
-	adap->dev.parent = &pdev->dev;
-	adap->dev.of_node = pdev->dev.of_node;
-	adap->quirks = &stu300_quirks;
-
-	i2c_set_adapdata(adap, dev);
-
-	/* i2c device drivers may be active on return from add_adapter() */
-	ret = i2c_add_numbered_adapter(adap);
-	if (ret)
-		return ret;
-
-	platform_set_drvdata(pdev, dev);
-	dev_info(&pdev->dev, "ST DDC I2C @ %p, irq %d\n",
-		 dev->virtbase, dev->irq);
-
-	return 0;
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int stu300_suspend(struct device *device)
-{
-	struct stu300_dev *dev = dev_get_drvdata(device);
-
-	/* Turn off everything */
-	stu300_wr8(0x00, dev->virtbase + I2C_CR);
-	return 0;
-}
-
-static int stu300_resume(struct device *device)
-{
-	int ret = 0;
-	struct stu300_dev *dev = dev_get_drvdata(device);
-
-	clk_enable(dev->clk);
-	ret = stu300_init_hw(dev);
-	clk_disable(dev->clk);
-
-	if (ret != 0)
-		dev_err(device, "error re-initializing hardware.\n");
-	return ret;
-}
-
-static SIMPLE_DEV_PM_OPS(stu300_pm, stu300_suspend, stu300_resume);
-#define STU300_I2C_PM	(&stu300_pm)
-#else
-#define STU300_I2C_PM	NULL
-#endif
-
-static int stu300_remove(struct platform_device *pdev)
-{
-	struct stu300_dev *dev = platform_get_drvdata(pdev);
-
-	i2c_del_adapter(&dev->adapter);
-	/* Turn off everything */
-	stu300_wr8(0x00, dev->virtbase + I2C_CR);
-	return 0;
-}
-
-static const struct of_device_id stu300_dt_match[] = {
-	{ .compatible = "st,ddci2c" },
-	{},
-};
-MODULE_DEVICE_TABLE(of, stu300_dt_match);
-
-static struct platform_driver stu300_i2c_driver = {
-	.driver = {
-		.name	= NAME,
-		.pm	= STU300_I2C_PM,
-		.of_match_table = stu300_dt_match,
-	},
-	.probe = stu300_probe,
-	.remove = stu300_remove,
-
-};
-
-static int __init stu300_init(void)
-{
-	return platform_driver_register(&stu300_i2c_driver);
-}
-
-static void __exit stu300_exit(void)
-{
-	platform_driver_unregister(&stu300_i2c_driver);
-}
-
-/*
- * The systems using this bus often have very basic devices such
- * as regulators on the I2C bus, so this needs to be loaded early.
- * Therefore it is registered in the subsys_initcall().
- */
-subsys_initcall(stu300_init);
-module_exit(stu300_exit);
-
-MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
-MODULE_DESCRIPTION("ST Micro DDC I2C adapter (" NAME ")");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:" NAME);