Merge branch 'i2c/for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "I2C has the following changes for you:

   - new flag to mark DMA safe buffers in i2c_msg. Also, some
     infrastructure around it. And docs.

   - huge refactoring of the at24 driver led by the new maintainer
     Bartosz

   - update I2C bus recovery to send STOP after recovery

   - conversion from gpio to gpiod for I2C bus recovery

   - adding a fault-injector to the i2c-gpio driver

   - lots of small driver improvements, and bigger ones to
     i2c-sh_mobile"

* 'i2c/for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (99 commits)
  i2c: mv64xxx: Add myself as maintainer for this driver
  i2c: mv64xxx: Fix clock resource by adding an optional bus clock
  i2c: mv64xxx: Remove useless test before clk_disable_unprepare
  i2c: mxs: use true and false for boolean values
  i2c: meson: update doc description to fix build warnings
  i2c: meson: add configurable divider factors
  dt-bindings: i2c: update documentation for the Meson-AXG
  i2c: imx-lpi2c: add runtime pm support
  i2c: rcar: fix some trivial typos in comments
  i2c: davinci: fix the cpufreq transition
  i2c: rk3x: add proper kerneldoc header
  i2c: rk3x: account for const type of of_device_id.data
  i2c: acorn: remove outdated path from file header
  i2c: acorn: add MODULE_LICENSE tag
  i2c: rcar: implement bus recovery
  i2c: send STOP after successful bus recovery
  i2c: ensure SDA is released in recovery if SDA is controllable
  i2c: add 'set_sda' to bus_recovery_info
  i2c: add identifier in declarations for i2c_bus_recovery
  i2c: make kerneldoc about bus recovery more precise
  ...

30 files changed, 1016 insertions, 931 deletions

diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index 1147bddb8b2c..3df0efd69ae3 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -649,6 +649,11 @@ static int __i2c_bit_add_bus(struct i2c_adapter *adap,
 	if (bit_adap->getscl == NULL)
 		adap->quirks = &i2c_bit_quirk_no_clk_stretch;
 
+	/* Bring bus to a known state. Looks like STOP if bus is not free yet */
+	setscl(bit_adap, 1);
+	udelay(bit_adap->udelay);
+	setsda(bit_adap, 1);
+
 	ret = add_adapter(adap);
 	if (ret < 0)
 		return ret;
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 009345d8f49d..a9805c7cb305 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -603,6 +603,14 @@ config I2C_GPIO
 	  This is a very simple bitbanging I2C driver utilizing the
 	  arch-neutral GPIO API to control the SCL and SDA lines.
 
+config I2C_GPIO_FAULT_INJECTOR
+	bool "GPIO-based fault injector"
+	depends on I2C_GPIO
+	help
+	  This adds some functionality to the i2c-gpio driver which can inject
+	  faults to an I2C bus, so another bus master can be stress-tested.
+	  This is for debugging. If unsure, say 'no'.
+
 config I2C_HIGHLANDER
 	tristate "Highlander FPGA SMBus interface"
 	depends on SH_HIGHLANDER
diff --git a/drivers/i2c/busses/i2c-acorn.c b/drivers/i2c/busses/i2c-acorn.c
index 9d7be5af2bf2..f4a5ae69bf6a 100644
--- a/drivers/i2c/busses/i2c-acorn.c
+++ b/drivers/i2c/busses/i2c-acorn.c
@@ -1,5 +1,5 @@
 /*
- *  linux/drivers/acorn/char/i2c.c
+ *  ARM IOC/IOMD i2c driver.
  *
  *  Copyright (C) 2000 Russell King
  *
@@ -7,8 +7,6 @@
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
- *  ARM IOC/IOMD i2c driver.
- *
  *  On Acorn machines, the following i2c devices are on the bus:
  *	- PCF8583 real time clock & static RAM
  */
@@ -94,3 +92,7 @@ static int __init i2c_ioc_init(void)
 }
 
 module_init(i2c_ioc_init);
+
+MODULE_AUTHOR("Russell King <linux@armlinux.org.uk>");
+MODULE_DESCRIPTION("ARM IOC/IOMD i2c driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 2ead9b9eebb7..75d6ab177055 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -33,7 +33,7 @@
 #include <linux/io.h>
 #include <linux/slab.h>
 #include <linux/cpufreq.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/of_device.h>
 #include <linux/platform_data/i2c-davinci.h>
 #include <linux/pm_runtime.h>
@@ -139,7 +139,6 @@ struct davinci_i2c_dev {
 	u8			terminate;
 	struct i2c_adapter	adapter;
 #ifdef CONFIG_CPU_FREQ
-	struct completion	xfr_complete;
 	struct notifier_block	freq_transition;
 #endif
 	struct davinci_i2c_platform_data *pdata;
@@ -294,7 +293,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
 }
 
 /*
- * This routine does i2c bus recovery by using i2c_generic_gpio_recovery
+ * 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)
@@ -316,7 +315,7 @@ static void davinci_i2c_unprepare_recovery(struct i2c_adapter *adap)
 }
 
 static struct i2c_bus_recovery_info davinci_i2c_gpio_recovery_info = {
-	.recover_bus = i2c_generic_gpio_recovery,
+	.recover_bus = i2c_generic_scl_recovery,
 	.prepare_recovery = davinci_i2c_prepare_recovery,
 	.unprepare_recovery = davinci_i2c_unprepare_recovery,
 };
@@ -567,9 +566,6 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	}
 
 	ret = num;
-#ifdef CONFIG_CPU_FREQ
-	complete(&dev->xfr_complete);
-#endif
 
 out:
 	pm_runtime_mark_last_busy(dev->dev);
@@ -717,13 +713,15 @@ static int i2c_davinci_cpufreq_transition(struct notifier_block *nb,
 	struct davinci_i2c_dev *dev;
 
 	dev = container_of(nb, struct davinci_i2c_dev, freq_transition);
+
+	i2c_lock_adapter(&dev->adapter);
 	if (val == CPUFREQ_PRECHANGE) {
-		wait_for_completion(&dev->xfr_complete);
 		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_adapter(&dev->adapter);
 
 	return 0;
 }
@@ -769,6 +767,7 @@ 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);
@@ -789,9 +788,7 @@ static int davinci_i2c_probe(struct platform_device *pdev)
 	}
 
 	init_completion(&dev->cmd_complete);
-#ifdef CONFIG_CPU_FREQ
-	init_completion(&dev->xfr_complete);
-#endif
+
 	dev->dev = &pdev->dev;
 	dev->irq = irq;
 	dev->pdata = dev_get_platdata(&pdev->dev);
@@ -868,10 +865,20 @@ static int davinci_i2c_probe(struct platform_device *pdev)
 
 	if (dev->pdata->has_pfunc)
 		adap->bus_recovery_info = &davinci_i2c_scl_recovery_info;
-	else if (dev->pdata->scl_pin) {
-		adap->bus_recovery_info = &davinci_i2c_gpio_recovery_info;
-		adap->bus_recovery_info->scl_gpio = dev->pdata->scl_pin;
-		adap->bus_recovery_info->sda_gpio = dev->pdata->sda_pin;
+	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;
diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
index d1a69372432f..27ebd90de43b 100644
--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -21,6 +21,7 @@
  * ----------------------------------------------------------------------------
  *
  */
+#include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/export.h>
 #include <linux/errno.h>
@@ -185,6 +186,19 @@ unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev)
 	return dev->get_clk_rate_khz(dev);
 }
 
+int i2c_dw_prepare_clk(struct dw_i2c_dev *dev, bool prepare)
+{
+	if (IS_ERR(dev->clk))
+		return PTR_ERR(dev->clk);
+
+	if (prepare)
+		return clk_prepare_enable(dev->clk);
+
+	clk_disable_unprepare(dev->clk);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(i2c_dw_prepare_clk);
+
 int i2c_dw_acquire_lock(struct dw_i2c_dev *dev)
 {
 	int ret;
@@ -217,7 +231,11 @@ int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
 	while (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
 		if (timeout <= 0) {
 			dev_warn(dev->dev, "timeout waiting for bus ready\n");
-			return -ETIMEDOUT;
+			i2c_recover_bus(&dev->adapter);
+
+			if (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY)
+				return -ETIMEDOUT;
+			return 0;
 		}
 		timeout--;
 		usleep_range(1000, 1100);
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 9fee4c054d3d..8707c76b2fee 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -284,6 +284,7 @@ struct dw_i2c_dev {
 	void			(*disable_int)(struct dw_i2c_dev *dev);
 	int			(*init)(struct dw_i2c_dev *dev);
 	int			mode;
+	struct i2c_bus_recovery_info rinfo;
 };
 
 #define ACCESS_SWAP		0x00000001
@@ -299,6 +300,7 @@ u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset);
 void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable);
 void __i2c_dw_enable_and_wait(struct dw_i2c_dev *dev, bool enable);
 unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev);
+int i2c_dw_prepare_clk(struct dw_i2c_dev *dev, bool prepare);
 int i2c_dw_acquire_lock(struct dw_i2c_dev *dev);
 void i2c_dw_release_lock(struct dw_i2c_dev *dev);
 int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev);
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 418c233075d3..ae691884d071 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -25,11 +25,13 @@
 #include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/export.h>
+#include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 
 #include "i2c-designware-core.h"
 
@@ -443,6 +445,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	if (!wait_for_completion_timeout(&dev->cmd_complete, adap->timeout)) {
 		dev_err(dev->dev, "controller timed out\n");
 		/* i2c_dw_init implicitly disables the adapter */
+		i2c_recover_bus(&dev->adapter);
 		i2c_dw_init_master(dev);
 		ret = -ETIMEDOUT;
 		goto done;
@@ -613,6 +616,56 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static void i2c_dw_prepare_recovery(struct i2c_adapter *adap)
+{
+	struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+
+	i2c_dw_disable(dev);
+	reset_control_assert(dev->rst);
+	i2c_dw_prepare_clk(dev, false);
+}
+
+static void i2c_dw_unprepare_recovery(struct i2c_adapter *adap)
+{
+	struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+
+	i2c_dw_prepare_clk(dev, true);
+	reset_control_deassert(dev->rst);
+	i2c_dw_init_master(dev);
+}
+
+static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
+{
+	struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
+	struct i2c_adapter *adap = &dev->adapter;
+	struct gpio_desc *gpio;
+	int r;
+
+	gpio = devm_gpiod_get(dev->dev, "scl", GPIOD_OUT_HIGH);
+	if (IS_ERR(gpio)) {
+		r = PTR_ERR(gpio);
+		if (r == -ENOENT)
+			return 0;
+		return r;
+	}
+	rinfo->scl_gpiod = gpio;
+
+	gpio = devm_gpiod_get_optional(dev->dev, "sda", GPIOD_IN);
+	if (IS_ERR(gpio))
+		return PTR_ERR(gpio);
+	rinfo->sda_gpiod = gpio;
+
+	rinfo->recover_bus = i2c_generic_scl_recovery;
+	rinfo->prepare_recovery = i2c_dw_prepare_recovery;
+	rinfo->unprepare_recovery = i2c_dw_unprepare_recovery;
+	adap->bus_recovery_info = rinfo;
+
+	dev_info(dev->dev, "running with gpio recovery mode! scl%s",
+		 rinfo->sda_gpiod ? ",sda" : "");
+
+	return 0;
+}
+
 int i2c_dw_probe(struct dw_i2c_dev *dev)
 {
 	struct i2c_adapter *adap = &dev->adapter;
@@ -652,6 +705,10 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
 		return ret;
 	}
 
+	ret = i2c_dw_init_recovery_info(dev);
+	if (ret)
+		return ret;
+
 	/*
 	 * Increment PM usage count during adapter registration in order to
 	 * avoid possible spurious runtime suspend when adapter device is
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 153b947702c5..5660daf6c92e 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -202,29 +202,6 @@ static void i2c_dw_configure_slave(struct dw_i2c_dev *dev)
 			 DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED;
 
 	dev->mode = DW_IC_SLAVE;
-
-	switch (dev->clk_freq) {
-	case 100000:
-		dev->slave_cfg |= DW_IC_CON_SPEED_STD;
-		break;
-	case 3400000:
-		dev->slave_cfg |= DW_IC_CON_SPEED_HIGH;
-		break;
-	default:
-		dev->slave_cfg |= DW_IC_CON_SPEED_FAST;
-	}
-}
-
-static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
-{
-	if (IS_ERR(i_dev->clk))
-		return PTR_ERR(i_dev->clk);
-
-	if (prepare)
-		return clk_prepare_enable(i_dev->clk);
-
-	clk_disable_unprepare(i_dev->clk);
-	return 0;
 }
 
 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
@@ -356,7 +333,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 		i2c_dw_configure_master(dev);
 
 	dev->clk = devm_clk_get(&pdev->dev, NULL);
-	if (!i2c_dw_plat_prepare_clk(dev, true)) {
+	if (!i2c_dw_prepare_clk(dev, true)) {
 		dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 
 		if (!dev->sda_hold_time && ht)
@@ -472,7 +449,7 @@ static int dw_i2c_plat_suspend(struct device *dev)
 	struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
 
 	i_dev->disable(i_dev);
-	i2c_dw_plat_prepare_clk(i_dev, false);
+	i2c_dw_prepare_clk(i_dev, false);
 
 	return 0;
 }
@@ -481,7 +458,7 @@ static int dw_i2c_plat_resume(struct device *dev)
 {
 	struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
 
-	i2c_dw_plat_prepare_clk(i_dev, true);
+	i2c_dw_prepare_clk(i_dev, true);
 	i_dev->init(i_dev);
 
 	return 0;
diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c
index ea9578ab19a1..d42558d1b002 100644
--- a/drivers/i2c/busses/i2c-designware-slave.c
+++ b/drivers/i2c/busses/i2c-designware-slave.c
@@ -51,9 +51,7 @@ static void i2c_dw_configure_fifo_slave(struct dw_i2c_dev *dev)
  */
 static int i2c_dw_init_slave(struct dw_i2c_dev *dev)
 {
-	u32 sda_falling_time, scl_falling_time;
 	u32 reg, comp_param1;
-	u32 hcnt, lcnt;
 	int ret;
 
 	ret = i2c_dw_acquire_lock(dev);
@@ -79,68 +77,6 @@ static int i2c_dw_init_slave(struct dw_i2c_dev *dev)
 	/* Disable the adapter. */
 	__i2c_dw_enable_and_wait(dev, false);
 
-	/* Set standard and fast speed deviders for high/low periods. */
-	sda_falling_time = dev->sda_falling_time ?: 300; /* ns */
-	scl_falling_time = dev->scl_falling_time ?: 300; /* ns */
-
-	/* Set SCL timing parameters for standard-mode. */
-	if (dev->ss_hcnt && dev->ss_lcnt) {
-		hcnt = dev->ss_hcnt;
-		lcnt = dev->ss_lcnt;
-	} else {
-		hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
-				       4000,	/* tHD;STA = tHIGH = 4.0 us */
-				       sda_falling_time,
-				       0,	/* 0: DW default, 1: Ideal */
-				       0);	/* No offset */
-		lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
-				       4700,	/* tLOW = 4.7 us */
-				       scl_falling_time,
-				       0);	/* No offset */
-	}
-	dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
-	dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
-	dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
-
-	/* Set SCL timing parameters for fast-mode or fast-mode plus. */
-	if ((dev->clk_freq == 1000000) && dev->fp_hcnt && dev->fp_lcnt) {
-		hcnt = dev->fp_hcnt;
-		lcnt = dev->fp_lcnt;
-	} else if (dev->fs_hcnt && dev->fs_lcnt) {
-		hcnt = dev->fs_hcnt;
-		lcnt = dev->fs_lcnt;
-	} else {
-		hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
-				       600,	/* tHD;STA = tHIGH = 0.6 us */
-				       sda_falling_time,
-				       0,	/* 0: DW default, 1: Ideal */
-				       0);	/* No offset */
-		lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
-				       1300,	/* tLOW = 1.3 us */
-				       scl_falling_time,
-				       0);	/* No offset */
-	}
-	dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
-	dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
-	dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
-
-	if ((dev->slave_cfg & DW_IC_CON_SPEED_MASK) ==
-		DW_IC_CON_SPEED_HIGH) {
-		if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
-			!= DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
-			dev_err(dev->dev, "High Speed not supported!\n");
-			dev->slave_cfg &= ~DW_IC_CON_SPEED_MASK;
-			dev->slave_cfg |= DW_IC_CON_SPEED_FAST;
-		} else if (dev->hs_hcnt && dev->hs_lcnt) {
-			hcnt = dev->hs_hcnt;
-			lcnt = dev->hs_lcnt;
-			dw_writel(dev, hcnt, DW_IC_HS_SCL_HCNT);
-			dw_writel(dev, lcnt, DW_IC_HS_SCL_LCNT);
-			dev_dbg(dev->dev, "HighSpeed-mode HCNT:LCNT = %d:%d\n",
-				hcnt, lcnt);
-		}
-	}
-
 	/* Configure SDA Hold Time if required. */
 	reg = dw_readl(dev, DW_IC_COMP_VERSION);
 	if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index 3855e0b11877..b02428498f6d 100644
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -170,7 +170,7 @@
 #define HSI2C_HS_TX_CLOCK	1000000
 #define HSI2C_FS_TX_CLOCK	100000
 
-#define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000))
+#define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(100))
 
 #define HSI2C_EXYNOS7	BIT(0)
 
diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c
index d80ea6ce91bb..58abb3eced58 100644
--- a/drivers/i2c/busses/i2c-gpio.c
+++ b/drivers/i2c/busses/i2c-gpio.c
@@ -7,6 +7,8 @@
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
+#include <linux/debugfs.h>
+#include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
 #include <linux/i2c-gpio.h>
@@ -23,6 +25,9 @@ struct i2c_gpio_private_data {
 	struct i2c_adapter adap;
 	struct i2c_algo_bit_data bit_data;
 	struct i2c_gpio_platform_data pdata;
+#ifdef CONFIG_I2C_GPIO_FAULT_INJECTOR
+	struct dentry *debug_dir;
+#endif
 };
 
 /*
@@ -34,7 +39,7 @@ static void i2c_gpio_setsda_val(void *data, int state)
 {
 	struct i2c_gpio_private_data *priv = data;
 
-	gpiod_set_value(priv->sda, state);
+	gpiod_set_value_cansleep(priv->sda, state);
 }
 
 /*
@@ -47,23 +52,125 @@ static void i2c_gpio_setscl_val(void *data, int state)
 {
 	struct i2c_gpio_private_data *priv = data;
 
-	gpiod_set_value(priv->scl, state);
+	gpiod_set_value_cansleep(priv->scl, state);
 }
 
 static int i2c_gpio_getsda(void *data)
 {
 	struct i2c_gpio_private_data *priv = data;
 
-	return gpiod_get_value(priv->sda);
+	return gpiod_get_value_cansleep(priv->sda);
 }
 
 static int i2c_gpio_getscl(void *data)
 {
 	struct i2c_gpio_private_data *priv = data;
 
-	return gpiod_get_value(priv->scl);
+	return gpiod_get_value_cansleep(priv->scl);
+}
+
+#ifdef CONFIG_I2C_GPIO_FAULT_INJECTOR
+static struct dentry *i2c_gpio_debug_dir;
+
+#define setsda(bd, val)	((bd)->setsda((bd)->data, val))
+#define setscl(bd, val)	((bd)->setscl((bd)->data, val))
+#define getsda(bd)	((bd)->getsda((bd)->data))
+#define getscl(bd)	((bd)->getscl((bd)->data))
+
+#define WIRE_ATTRIBUTE(wire) \
+static int fops_##wire##_get(void *data, u64 *val)	\
+{							\
+	struct i2c_gpio_private_data *priv = data;	\
+							\
+	i2c_lock_adapter(&priv->adap);			\
+	*val = get##wire(&priv->bit_data);		\
+	i2c_unlock_adapter(&priv->adap);		\
+	return 0;					\
+}							\
+static int fops_##wire##_set(void *data, u64 val)	\
+{							\
+	struct i2c_gpio_private_data *priv = data;	\
+							\
+	i2c_lock_adapter(&priv->adap);			\
+	set##wire(&priv->bit_data, val);		\
+	i2c_unlock_adapter(&priv->adap);		\
+	return 0;					\
+}							\
+DEFINE_DEBUGFS_ATTRIBUTE(fops_##wire, fops_##wire##_get, fops_##wire##_set, "%llu\n")
+
+WIRE_ATTRIBUTE(scl);
+WIRE_ATTRIBUTE(sda);
+
+static int fops_incomplete_transfer_set(void *data, u64 addr)
+{
+	struct i2c_gpio_private_data *priv = data;
+	struct i2c_algo_bit_data *bit_data = &priv->bit_data;
+	int i, pattern;
+
+	if (addr > 0x7f)
+		return -EINVAL;
+
+	/* ADDR (7 bit) + RD (1 bit) + SDA hi (1 bit) */
+	pattern = (addr << 2) | 3;
+
+	i2c_lock_adapter(&priv->adap);
+
+	/* START condition */
+	setsda(bit_data, 0);
+	udelay(bit_data->udelay);
+
+	/* Send ADDR+RD, request ACK, don't send STOP */
+	for (i = 8; i >= 0; i--) {
+		setscl(bit_data, 0);
+		udelay(bit_data->udelay / 2);
+		setsda(bit_data, (pattern >> i) & 1);
+		udelay((bit_data->udelay + 1) / 2);
+		setscl(bit_data, 1);
+		udelay(bit_data->udelay);
+	}
+
+	i2c_unlock_adapter(&priv->adap);
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(fops_incomplete_transfer, NULL, fops_incomplete_transfer_set, "%llu\n");
+
+static void i2c_gpio_fault_injector_init(struct platform_device *pdev)
+{
+	struct i2c_gpio_private_data *priv = platform_get_drvdata(pdev);
+
+	/*
+	 * If there will be a debugfs-dir per i2c adapter somewhen, put the
+	 * 'fault-injector' dir there. Until then, we have a global dir with
+	 * all adapters as subdirs.
+	 */
+	if (!i2c_gpio_debug_dir) {
+		i2c_gpio_debug_dir = debugfs_create_dir("i2c-fault-injector", NULL);
+		if (!i2c_gpio_debug_dir)
+			return;
+	}
+
+	priv->debug_dir = debugfs_create_dir(pdev->name, i2c_gpio_debug_dir);
+	if (!priv->debug_dir)
+		return;
+
+	debugfs_create_file_unsafe("scl", 0600, priv->debug_dir, priv, &fops_scl);
+	debugfs_create_file_unsafe("sda", 0600, priv->debug_dir, priv, &fops_sda);
+	debugfs_create_file_unsafe("incomplete_transfer", 0200, priv->debug_dir,
+				   priv, &fops_incomplete_transfer);
 }
 
+static void i2c_gpio_fault_injector_exit(struct platform_device *pdev)
+{
+	struct i2c_gpio_private_data *priv = platform_get_drvdata(pdev);
+
+	debugfs_remove_recursive(priv->debug_dir);
+}
+#else
+static inline void i2c_gpio_fault_injector_init(struct platform_device *pdev) {}
+static inline void i2c_gpio_fault_injector_exit(struct platform_device *pdev) {}
+#endif /* CONFIG_I2C_GPIO_FAULT_INJECTOR*/
+
 static void of_i2c_gpio_get_props(struct device_node *np,
 				  struct i2c_gpio_platform_data *pdata)
 {
@@ -179,6 +286,9 @@ static int i2c_gpio_probe(struct platform_device *pdev)
 	if (IS_ERR(priv->scl))
 		return PTR_ERR(priv->scl);
 
+	if (gpiod_cansleep(priv->sda) || gpiod_cansleep(priv->scl))
+		dev_warn(dev, "Slow GPIO pins might wreak havoc into I2C/SMBus bus timing");
+
 	bit_data->setsda = i2c_gpio_setsda_val;
 	bit_data->setscl = i2c_gpio_setscl_val;
 
@@ -228,6 +338,8 @@ static int i2c_gpio_probe(struct platform_device *pdev)
 		 pdata->scl_is_output_only
 		 ? ", no clock stretching" : "");
 
+	i2c_gpio_fault_injector_init(pdev);
+
 	return 0;
 }
 
@@ -236,6 +348,8 @@ static int i2c_gpio_remove(struct platform_device *pdev)
 	struct i2c_gpio_private_data *priv;
 	struct i2c_adapter *adap;
 
+	i2c_gpio_fault_injector_exit(pdev);
+
 	priv = platform_get_drvdata(pdev);
 	adap = &priv->adap;
 
diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
index e86801a63120..e6da2c7a9a3e 100644
--- a/drivers/i2c/busses/i2c-imx-lpi2c.c
+++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
@@ -30,6 +30,7 @@
 #include <linux/of_device.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 
@@ -90,6 +91,8 @@
 #define FAST_PLUS_MAX_BITRATE	3400000
 #define HIGHSPEED_MAX_BITRATE	5000000
 
+#define I2C_PM_TIMEOUT		10 /* ms */
+
 enum lpi2c_imx_mode {
 	STANDARD,	/* 100+Kbps */
 	FAST,		/* 400+Kbps */
@@ -274,8 +277,8 @@ static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
 	unsigned int temp;
 	int ret;
 
-	ret = clk_enable(lpi2c_imx->clk);
-	if (ret)
+	ret = pm_runtime_get_sync(lpi2c_imx->adapter.dev.parent);
+	if (ret < 0)
 		return ret;
 
 	temp = MCR_RST;
@@ -284,7 +287,7 @@ static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
 
 	ret = lpi2c_imx_config(lpi2c_imx);
 	if (ret)
-		goto clk_disable;
+		goto rpm_put;
 
 	temp = readl(lpi2c_imx->base + LPI2C_MCR);
 	temp |= MCR_MEN;
@@ -292,8 +295,9 @@ static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
 
 	return 0;
 
-clk_disable:
-	clk_disable(lpi2c_imx->clk);
+rpm_put:
+	pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);
+	pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);
 
 	return ret;
 }
@@ -306,7 +310,8 @@ static int lpi2c_imx_master_disable(struct lpi2c_imx_struct *lpi2c_imx)
 	temp &= ~MCR_MEN;
 	writel(temp, lpi2c_imx->base + LPI2C_MCR);
 
-	clk_disable(lpi2c_imx->clk);
+	pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);
+	pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);
 
 	return 0;
 }
@@ -606,22 +611,31 @@ static int lpi2c_imx_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_get_noresume(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
 	temp = readl(lpi2c_imx->base + LPI2C_PARAM);
 	lpi2c_imx->txfifosize = 1 << (temp & 0x0f);
 	lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f);
 
-	clk_disable(lpi2c_imx->clk);
-
 	ret = i2c_add_adapter(&lpi2c_imx->adapter);
 	if (ret)
-		goto clk_unprepare;
+		goto rpm_disable;
+