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  i2c: acorn: remove outdated path from file header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
  ...

Documentation/devicetree/bindings/eeprom/at24.txt

+EEPROMs (I2C)
+
+Required properties:
+
+  - compatible: Must be a "<manufacturer>,<model>" pair. The following <model>
+                values are supported (assuming "atmel" as manufacturer):
+
+                "atmel,24c00",
+                "atmel,24c01",
+                "atmel,24cs01",
+                "atmel,24c02",
+                "atmel,24cs02",
+                "atmel,24mac402",
+                "atmel,24mac602",
+                "atmel,spd",
+                "atmel,24c04",
+                "atmel,24cs04",
+                "atmel,24c08",
+                "atmel,24cs08",
+                "atmel,24c16",
+                "atmel,24cs16",
+                "atmel,24c32",
+                "atmel,24cs32",
+                "atmel,24c64",
+                "atmel,24cs64",
+                "atmel,24c128",
+                "atmel,24c256",
+                "atmel,24c512",
+                "atmel,24c1024",
+
+                If <manufacturer> is not "atmel", then a fallback must be used
+                with the same <model> and "atmel" as manufacturer.
+
+                Example:
+                        compatible = "microchip,24c128", "atmel,24c128";
+
+                Supported manufacturers are:
+
+                "catalyst",
+                "microchip",
+                "ramtron",
+                "renesas",
+                "nxp",
+                "st",
+
+                Some vendors use different model names for chips which are just
+                variants of the above. Known such exceptions are listed below:
+
+                "renesas,r1ex24002" - the fallback is "atmel,24c02"
+
+  - reg: The I2C address of the EEPROM.
+
+Optional properties:
+
+  - pagesize: The length of the pagesize for writing. Please consult the
+              manual of your device, that value varies a lot. A wrong value
+              may result in data loss! If not specified, a safety value of
+              '1' is used which will be very slow.
+
+  - read-only: This parameterless property disables writes to the eeprom.
+
+  - size: Total eeprom size in bytes.
+
+  - no-read-rollover: This parameterless property indicates that the
+                      multi-address eeprom does not automatically roll over
+                      reads to the next slave address. Please consult the
+                      manual of your device.
+
+  - wp-gpios: GPIO to which the write-protect pin of the chip is connected.
+
+Example:
+
+eeprom@52 {
+	compatible = "atmel,24c32";
+	reg = <0x52>;
+	pagesize = <32>;
+	wp-gpios = <&gpio1 3 0>;
+};

Documentation/devicetree/bindings/eeprom/eeprom.txt

-EEPROMs (I2C)
-
-Required properties:
-
-  - compatible : should be "<manufacturer>,<type>", like these:
-
-	"atmel,24c00", "atmel,24c01", "atmel,24c02", "atmel,24c04",
-	"atmel,24c08", "atmel,24c16", "atmel,24c32", "atmel,24c64",
-	"atmel,24c128", "atmel,24c256", "atmel,24c512", "atmel,24c1024"
-
-	"catalyst,24c32"
-
-	"microchip,24c128"
-
-	"ramtron,24c64"
-
-	"renesas,r1ex24002"
-
-	The following manufacturers values have been deprecated:
-	"at", "at24"
-
-	 If there is no specific driver for <manufacturer>, a generic
-	 device with <type> and manufacturer "atmel" should be used.
-	 Possible types are:
-	 "24c00", "24c01", "24c02", "24c04", "24c08", "24c16", "24c32", "24c64",
-	 "24c128", "24c256", "24c512", "24c1024", "spd"
-
-  - reg : the I2C address of the EEPROM
-
-Optional properties:
-
-  - pagesize : the length of the pagesize for writing. Please consult the
-               manual of your device, that value varies a lot. A wrong value
-	       may result in data loss! If not specified, a safety value of
-	       '1' is used which will be very slow.
-
-  - read-only: this parameterless property disables writes to the eeprom
-
-  - size: total eeprom size in bytes
-
-Example:
-
-eeprom@52 {
-	compatible = "atmel,24c32";
-	reg = <0x52>;
-	pagesize = <32>;
-};

Documentation/devicetree/bindings/i2c/i2c-meson.txt

 Amlogic Meson I2C controller
 
 Required properties:
- - compatible: must be "amlogic,meson6-i2c" or "amlogic,meson-gxbb-i2c"
+ - compatible: must be:
+	"amlogic,meson6-i2c" for Meson8 and compatible SoCs
+	"amlogic,meson-gxbb-i2c" for GXBB and compatible SoCs
+	"amlogic,meson-axg-i2c"for AXG and compatible SoCs
+
  - reg: physical address and length of the device registers
  - interrupts: a single interrupt specifier
  - clocks: clock for the device

Documentation/devicetree/bindings/i2c/i2c-mtk.txt

@@ -5,6 +5,7 @@ The MediaTek's I2C controller is used to interface with I2C devices.
 Required properties:
   - compatible: value should be either of the following.
       "mediatek,mt2701-i2c", "mediatek,mt6577-i2c": for MediaTek MT2701
+      "mediatek,mt2712-i2c": for MediaTek MT2712
       "mediatek,mt6577-i2c": for MediaTek MT6577
       "mediatek,mt6589-i2c": for MediaTek MT6589
       "mediatek,mt7622-i2c": for MediaTek MT7622

Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt

 * NXP PCA954x I2C bus switch
 
+The driver supports NXP PCA954x and PCA984x I2C mux/switch devices.
+
 Required Properties:
 
   - compatible: Must contain one of the following.
-    "nxp,pca9540", "nxp,pca9542", "nxp,pca9543", "nxp,pca9544",
-    "nxp,pca9545", "nxp,pca9546", "nxp,pca9547", "nxp,pca9548"
+    "nxp,pca9540",
+    "nxp,pca9542",
+    "nxp,pca9543",
+    "nxp,pca9544",
+    "nxp,pca9545",
+    "nxp,pca9546", "nxp,pca9846",
+    "nxp,pca9547", "nxp,pca9847",
+    "nxp,pca9548", "nxp,pca9848",
+    "nxp,pca9849"
 
   - reg: The I2C address of the device.
 

Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt

@@ -25,6 +25,15 @@ default frequency is 100kHz
                      whenever you're using the "allwinner,sun6i-a31-i2c"
                      compatible.
 
+ - clocks:	   : pointers to the reference clocks for this device, the
+		     first one is the one used for the clock on the i2c bus,
+		     the second one is the clock used to acces the registers
+		     of the controller
+
+ - clock-names	   : names of used clocks, mandatory if the second clock is
+		     used, the name must be "core", and "reg" (the latter is
+		     only for Armada 7K/8K).
+
 Examples:
 
 	i2c@11000 {
@@ -42,3 +51,14 @@ For the Armada XP:
 		interrupts = <29>;
 		clock-frequency = <100000>;
 	};
+
+For the Armada 7040:
+
+	i2c@701000 {
+		compatible = "marvell,mv78230-i2c";
+		reg = <0x701000 0x20>;
+		interrupts = <29>;
+		clock-frequency = <100000>;
+		clock-names = "core", "reg";
+		clocks = <&core_clock>, <&reg_clock>;
+	};

Documentation/i2c/DMA-considerations

+=================
+Linux I2C and DMA
+=================
+
+Given that i2c is a low-speed bus, over which the majority of messages
+transferred are small, it is not considered a prime user of DMA access. At this
+time of writing, only 10% of I2C bus master drivers have DMA support
+implemented. And the vast majority of transactions are so small that setting up
+DMA for it will likely add more overhead than a plain PIO transfer.
+
+Therefore, it is *not* mandatory that the buffer of an I2C message is DMA safe.
+It does not seem reasonable to apply additional burdens when the feature is so
+rarely used. However, it is recommended to use a DMA-safe buffer if your
+message size is likely applicable for DMA. Most drivers have this threshold
+around 8 bytes (as of today, this is mostly an educated guess, however). For
+any message of 16 byte or larger, it is probably a really good idea. Please
+note that other subsystems you use might add requirements. E.g., if your
+I2C bus master driver is using USB as a bridge, then you need to have DMA
+safe buffers always, because USB requires it.
+
+Clients
+-------
+
+For clients, if you use a DMA safe buffer in i2c_msg, set the I2C_M_DMA_SAFE
+flag with it. Then, the I2C core and drivers know they can safely operate DMA
+on it. Note that using this flag is optional. I2C host drivers which are not
+updated to use this flag will work like before. And like before, they risk
+using an unsafe DMA buffer. To improve this situation, using I2C_M_DMA_SAFE in
+more and more clients and host drivers is the planned way forward. Note also
+that setting this flag makes only sense in kernel space. User space data is
+copied into kernel space anyhow. The I2C core makes sure the destination
+buffers in kernel space are always DMA capable. Also, when the core emulates
+SMBus transactions via I2C, the buffers for block transfers are DMA safe. Users
+of i2c_master_send() and i2c_master_recv() functions can now use DMA safe
+variants (i2c_master_send_dmasafe() and i2c_master_recv_dmasafe()) once they
+know their buffers are DMA safe. Users of i2c_transfer() must set the
+I2C_M_DMA_SAFE flag manually.
+
+Masters
+-------
+
+Bus master drivers wishing to implement safe DMA can use helper functions from
+the I2C core. One gives you a DMA-safe buffer for a given i2c_msg as long as a
+certain threshold is met::
+
+	dma_buf = i2c_get_dma_safe_msg_buf(msg, threshold_in_byte);
+
+If a buffer is returned, it is either msg->buf for the I2C_M_DMA_SAFE case or a
+bounce buffer. But you don't need to care about that detail, just use the
+returned buffer. If NULL is returned, the threshold was not met or a bounce
+buffer could not be allocated. Fall back to PIO in that case.
+
+In any case, a buffer obtained from above needs to be released. It ensures data
+is copied back to the message and a potentially used bounce buffer is freed::
+
+	i2c_release_dma_safe_msg_buf(msg, dma_buf);
+
+The bounce buffer handling from the core is generic and simple. It will always
+allocate a new bounce buffer. If you want a more sophisticated handling (e.g.
+reusing pre-allocated buffers), you are free to implement your own.
+
+Please also check the in-kernel documentation for details. The i2c-sh_mobile
+driver can be used as a reference example how to use the above helpers.
+
+Final note: If you plan to use DMA with I2C (or with anything else, actually)
+make sure you have CONFIG_DMA_API_DEBUG enabled during development. It can help
+you find various issues which can be complex to debug otherwise.

Documentation/i2c/gpio-fault-injection

+Linux I2C fault injection
+=========================
+
+The GPIO based I2C bus master driver can be configured to provide fault
+injection capabilities. It is then meant to be connected to another I2C bus
+which is driven by the I2C bus master driver under test. The GPIO fault
+injection driver can create special states on the bus which the other I2C bus
+master driver should handle gracefully.
+
+Once the Kconfig option I2C_GPIO_FAULT_INJECTOR is enabled, there will be an
+'i2c-fault-injector' subdirectory in the Kernel debugfs filesystem, usually
+mounted at /sys/kernel/debug. There will be a separate subdirectory per GPIO
+driven I2C bus. Each subdirectory will contain files to trigger the fault
+injection. They will be described now along with their intended use-cases.
+
+"scl"
+-----
+
+By reading this file, you get the current state of SCL. By writing, you can
+change its state to either force it low or to release it again. So, by using
+"echo 0 > scl" you force SCL low and thus, no communication will be possible
+because the bus master under test will not be able to clock. It should detect
+the condition of SCL being unresponsive and report an error to the upper
+layers.
+
+"sda"
+-----
+
+By reading this file, you get the current state of SDA. By writing, you can
+change its state to either force it low or to release it again. So, by using
+"echo 0 > sda" you force SDA low and thus, data cannot be transmitted. The bus
+master under test should detect this condition and trigger a bus recovery (see
+I2C specification version 4, section 3.1.16) using the helpers of the Linux I2C
+core (see 'struct bus_recovery_info'). However, the bus recovery will not
+succeed because SDA is still pinned low until you manually release it again
+with "echo 1 > sda". A test with an automatic release can be done with the
+'incomplete_transfer' file.
+
+"incomplete_transfer"
+---------------------
+
+This file is write only and you need to write the address of an existing I2C
+client device to it. Then, a transfer to this device will be started, but it
+will stop at the ACK phase after the address of the client has been
+transmitted. Because the device will ACK its presence, this results in SDA
+being pulled low by the device while SCL is high. So, similar to the "sda" file
+above, the bus master under test should detect this condition and try a bus
+recovery. This time, however, it should succeed and the device should release
+SDA after toggling SCL. Please note: there are I2C client devices which detect
+a stuck SDA on their side and release it on their own after a few milliseconds.
+Also, there are external devices deglitching and monitoring the I2C bus. They
+can also detect a stuck SDA and will init a bus recovery on their own. If you
+want to implement bus recovery in a bus master driver, make sure you checked
+your hardware setup carefully before.

MAINTAINERS

@@ -2288,7 +2288,9 @@ F:	include/linux/async_tx.h
 AT24 EEPROM DRIVER
 M:	Bartosz Golaszewski <brgl@bgdev.pl>
 L:	linux-i2c@vger.kernel.org
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git
 S:	Maintained
+F:	Documentation/devicetree/bindings/eeprom/at24.txt
 F:	drivers/misc/eeprom/at24.c
 F:	include/linux/platform_data/at24.h
 
@@ -6580,6 +6582,12 @@ F:	drivers/i2c/i2c-mux.c
 F:	drivers/i2c/muxes/
 F:	include/linux/i2c-mux.h
 
+I2C MV64XXX MARVELL AND ALLWINNER DRIVER
+M:	Gregory CLEMENT <gregory.clement@free-electrons.com>
+L:	linux-i2c@vger.kernel.org
+S:	Maintained
+F:	drivers/i2c/busses/i2c-mv64xxx.c
+
 I2C OVER PARALLEL PORT
 M:	Jean Delvare <jdelvare@suse.com>
 L:	linux-i2c@vger.kernel.org

arch/arm/mach-davinci/board-dm355-evm.c

@@ -17,6 +17,7 @@
 #include <linux/mtd/rawnand.h>
 #include <linux/i2c.h>
 #include <linux/gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/clk.h>
 #include <linux/videodev2.h>
 #include <media/i2c/tvp514x.h>
@@ -108,11 +109,20 @@ static struct platform_device davinci_nand_device = {
 	},
 };
 
+static struct gpiod_lookup_table i2c_recovery_gpiod_table = {
+	.dev_id = "i2c_davinci",
+	.table = {
+		GPIO_LOOKUP("davinci_gpio", 15, "sda",
+			    GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN),
+		GPIO_LOOKUP("davinci_gpio", 14, "scl",
+			    GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN),
+	},
+};
+
 static struct davinci_i2c_platform_data i2c_pdata = {
 	.bus_freq	= 400	/* kHz */,
 	.bus_delay	= 0	/* usec */,
-	.sda_pin        = 15,
-	.scl_pin        = 14,
+	.gpio_recovery	= true,
 };
 
 static int dm355evm_mmc_gpios = -EINVAL;
@@ -141,6 +151,7 @@ static struct i2c_board_info dm355evm_i2c_info[] = {
 
 static void __init evm_init_i2c(void)
 {
+	gpiod_add_lookup_table(&i2c_recovery_gpiod_table);
 	davinci_init_i2c(&i2c_pdata);
 
 	gpio_request(5, "dm355evm_msp");

arch/arm/mach-davinci/board-dm644x-evm.c

@@ -13,6 +13,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/platform_device.h>
 #include <linux/gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/i2c.h>
 #include <linux/platform_data/pcf857x.h>
 #include <linux/platform_data/at24.h>
@@ -595,18 +596,28 @@ static struct i2c_board_info __initdata i2c_info[] =  {
 	},
 };
 
+static struct gpiod_lookup_table i2c_recovery_gpiod_table = {
+	.dev_id = "i2c_davinci",
+	.table = {
+		GPIO_LOOKUP("davinci_gpio", 44, "sda",
+			    GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN),
+		GPIO_LOOKUP("davinci_gpio", 43, "scl",
+			    GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN),
+	},
+};
+
 /* The msp430 uses a slow bitbanged I2C implementation (ergo 20 KHz),
  * which requires 100 usec of idle bus after i2c writes sent to it.
  */
 static struct davinci_i2c_platform_data i2c_pdata = {
 	.bus_freq	= 20 /* kHz */,
 	.bus_delay	= 100 /* usec */,
-	.sda_pin        = 44,
-	.scl_pin        = 43,
+	.gpio_recovery	= true,
 };
 
 static void __init evm_init_i2c(void)
 {
+	gpiod_add_lookup_table(&i2c_recovery_gpiod_table);
 	davinci_init_i2c(&i2c_pdata);
 	i2c_add_driver(&dm6446evm_msp_driver);
 	i2c_register_board_info(1, i2c_info, ARRAY_SIZE(i2c_info));

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;

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

drivers/i2c/busses/i2c-acorn.c

 /*
- *  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");

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;

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");
+			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);

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);

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

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;

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) {

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)
 

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;
 

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;
+
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
 
 	dev_info(&lpi2c_imx->adapter.dev, "LPI2C adapter registered\n");
 
 	return 0;
 
-clk_unprepare:
-	clk_unprepare(lpi2c_imx->clk);
+rpm_disable:
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 
 	return ret;
 }
@@ -632,28 +646,48 @@ static int lpi2c_imx_remove(struct platform_device *pdev)
 
 	i2c_del_adapter(&lpi2c_imx->adapter);
 
-	clk_unprepare(lpi2c_imx->clk);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 
 	return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
-static int lpi2c_imx_suspend(struct device *dev)
+static int lpi2c_runtime_suspend(struct device *dev)
 {
+	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(lpi2c_imx->clk);
 	pinctrl_pm_select_sleep_state(dev);
 
 	return 0;
 }
 
-static int lpi2c_imx_resume(struct device *dev)
+static int lpi2c_runtime_resume(struct device *dev)
 {
+	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
+	int ret;
+
 	pinctrl_pm_select_default_state(dev);
+	ret = clk_prepare_enable(lpi2c_imx->clk);
+	if (ret) {
+		dev_err(dev, "failed to enable I2C clock, ret=%d\n", ret);
+		return ret;
+	}
 
 	return 0;
 }
-#endif
 
-static SIMPLE_DEV_PM_OPS(imx_lpi2c_pm, lpi2c_imx_suspend, lpi2c_imx_resume);
+static const struct dev_pm_ops lpi2c_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				      pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(lpi2c_runtime_suspend,
+			   lpi2c_runtime_resume, NULL)
+};
+#define IMX_LPI2C_PM      (&lpi2c_pm_ops)
+#else
+#define IMX_LPI2C_PM      NULL
+#endif
 
 static struct platform_driver lpi2c_imx_driver = {
 	.probe = lpi2c_imx_probe,
@@ -661,7 +695,7 @@ static struct platform_driver lpi2c_imx_driver = {
 	.driver = {
 		.name = DRIVER_NAME,
 		.of_match_table = lpi2c_imx_of_match,
-		.pm = &imx_lpi2c_pm,
+		.pm = IMX_LPI2C_PM,
 	},
 };
 

drivers/i2c/busses/i2c-imx.c

@@ -37,6 +37,7 @@
 #include <linux/dmapool.h>
 #include <linux/err.h>
 #include <linux/errno.h>
+#include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
@@ -46,7 +47,6 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_dma.h>
-#include <linux/of_gpio.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_data/i2c-imx.h>
 #include <linux/platform_device.h>
@@ -1006,26 +1006,26 @@ static int i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx,
 			PINCTRL_STATE_DEFAULT);
 	i2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(i2c_imx->pinctrl,
 			"gpio");
-	rinfo->sda_gpio = of_get_named_gpio(pdev->dev.of_node, "sda-gpios", 0);
-	rinfo->scl_gpio = of_get_named_gpio(pdev->dev.of_node, "scl-gpios", 0);
+	rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN);
+	rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", GPIOD_OUT_HIGH);
 
-	if (rinfo->sda_gpio == -EPROBE_DEFER ||
-	    rinfo->scl_gpio == -EPROBE_DEFER) {
+	if (PTR_ERR(rinfo->sda_gpiod) == -EPROBE_DEFER ||
+	    PTR_ERR(rinfo->scl_gpiod) == -EPROBE_DEFER) {
 		return -EPROBE_DEFER;
-	} else if (!gpio_is_valid(rinfo->sda_gpio) ||
-		   !gpio_is_valid(rinfo->scl_gpio) ||
+	} else if (IS_ERR(rinfo->sda_gpiod) ||
+		   IS_ERR(rinfo->scl_gpiod) ||
 		   IS_ERR(i2c_imx->pinctrl_pins_default) ||
 		   IS_ERR(i2c_imx->pinctrl_pins_gpio)) {
 		dev_dbg(&pdev->dev, "recovery information incomplete\n");
 		return 0;
 	}
 
-	dev_dbg(&pdev->dev, "using scl-gpio %d and sda-gpio %d for recovery\n",
-			rinfo->scl_gpio, rinfo->sda_gpio);
+	dev_dbg(&pdev->dev, "using scl%s for recovery\n",
+		rinfo->sda_gpiod ? ",sda" : "");
 
 	rinfo->prepare_recovery = i2c_imx_prepare_recovery;
 	rinfo->unprepare_recovery = i2c_imx_unprepare_recovery;
-	rinfo->recover_bus = i2c_generic_gpio_recovery;
+	rinfo->recover_bus = i2c_generic_scl_recovery;
 	i2c_imx->adapter.bus_recovery_info = rinfo;
 
 	return 0;

drivers/i2c/busses/i2c-ismt.c

@@ -172,7 +172,7 @@ struct ismt_priv {
 	dma_addr_t io_rng_dma;			/* descriptor HW base addr */
 	u8 head;				/* ring buffer head pointer */
 	struct completion cmp;			/* interrupt completion */
-	u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 1];	/* temp R/W data buffer */
+	u8 buffer[I2C_SMBUS_BLOCK_MAX + 16];	/* temp R/W data buffer */
 };
 
 /**
@@ -320,10 +320,12 @@ static int ismt_process_desc(const struct ismt_desc *desc,
 			     struct ismt_priv *priv, int size,
 			     char read_write)
 {
-	u8 *dma_buffer = priv->dma_buffer;
+	u8 *dma_buffer = PTR_ALIGN(&priv->buffer[0], 16);
 
 	dev_dbg(&priv->pci_dev->dev, "Processing completed descriptor\n");
 	__ismt_desc_dump(&priv->pci_dev->dev, desc);
+	ismt_gen_reg_dump(priv);
+	ismt_mstr_reg_dump(priv);
 
 	if (desc->status & ISMT_DESC_SCS) {
 		if (read_write == I2C_SMBUS_WRITE &&
@@ -393,11 +395,12 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr,
 	struct ismt_desc *desc;
 	struct ismt_priv *priv = i2c_get_adapdata(adap);
 	struct device *dev = &priv->pci_dev->dev;
+	u8 *dma_buffer = PTR_ALIGN(&priv->buffer[0], 16);
 
 	desc = &priv->hw[priv->head];
 
 	/* Initialize the DMA buffer */
-	memset(priv->dma_buffer, 0, sizeof(priv->dma_buffer));
+	memset(priv->buffer, 0, sizeof(priv->buffer));
 
 	/* Initialize the descriptor */
 	memset(desc, 0, sizeof(struct ismt_desc));
@@ -446,8 +449,8 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr,
 			desc->wr_len_cmd = 2;
 			dma_size = 2;
 			dma_direction = DMA_TO_DEVICE;
-			priv->dma_buffer[0] = command;
-			priv->dma_buffer[1] = data->byte;
+			dma_buffer[0] = command;
+			dma_buffer[1] = data->byte;
 		} else {
 			/* Read Byte */
 			dev_dbg(dev, "I2C_SMBUS_BYTE_DATA:  READ\n");
@@ -466,9 +469,9 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr,
 			desc->wr_len_cmd = 3;
 			dma_size = 3;
 			dma_direction = DMA_TO_DEVICE;
-			priv->dma_buffer[0] = command;
-			priv->dma_buffer[1] = data->word & 0xff;
-			priv->dma_buffer[2] = data->word >> 8;
+			dma_buffer[0] = command;
+			dma_buffer[1] = data->word & 0xff;
+			dma_buffer[2] = data->word >> 8;
 		} else {
 			/* Read Word */
 			dev_dbg(dev, "I2C_SMBUS_WORD_DATA:  READ\n");
@@ -486,9 +489,9 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr,
 		desc->rd_len = 2;
 		dma_size = 3;
 		dma_direction = DMA_BIDIRECTIONAL;
-		priv->dma_buffer[0] = command;
-		priv->dma_buffer[1] = data->word & 0xff;
-		priv->dma_buffer[2] = data->word >> 8;
+		dma_buffer[0] = command;
+		dma_buffer[1] = data->word & 0xff;
+		dma_buffer[2] = data->word >> 8;
 		break;
 
 	case I2C_SMBUS_BLOCK_DATA:
@@ -499,8 +502,8 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr,
 			dma_direction = DMA_TO_DEVICE;
 			desc->wr_len_cmd = dma_size;
 			desc->control |= ISMT_DESC_BLK;
-			priv->dma_buffer[0] = command;
-			memcpy(&priv->dma_buffer[1], &data->block[1], dma_size - 1);
+			dma_buffer[0] = command;
+			memcpy(&dma_buffer[1], &data->block[1], dma_size - 1);
 		} else {
 			/* Block Read */
 			dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA:  READ\n");
@@ -527,8 +530,8 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr,
 			dma_direction = DMA_TO_DEVICE;
 			desc->wr_len_cmd = dma_size;
 			desc->control |= ISMT_DESC_I2C;
-			priv->dma_buffer[0] = command;
-			memcpy(&priv->dma_buffer[1], &data->block[1], dma_size - 1);
+			dma_buffer[0] = command;
+			memcpy(&dma_buffer[1], &data->block[1], dma_size - 1);
 		} else {
 			/* i2c Block Read */
 			dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA:  READ\n");
@@ -557,23 +560,22 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr,
 	if (dma_size != 0) {
 		dev_dbg(dev, " dev=%p\n", dev);
 		dev_dbg(dev, " data=%p\n", data);
-		dev_dbg(dev, " dma_buffer=%p\n", priv->dma_buffer);
+		dev_dbg(dev, " dma_buffer=%p\n", dma_buffer);
 		dev_dbg(dev, " dma_size=%d\n", dma_size);
 		dev_dbg(dev, " dma_direction=%d\n", dma_direction);
 
 		dma_addr = dma_map_single(dev,
-				      priv->dma_buffer,
+				      dma_buffer,
 				      dma_size,
 				      dma_direction);
 
 		if (dma_mapping_error(dev, dma_addr)) {
 			dev_err(dev, "Error in mapping dma buffer %p\n",
-				priv->dma_buffer);
+				dma_buffer);
 			return -EIO;
 		}
 
-		dev_dbg(dev, " dma_addr = 0x%016llX\n",
-			(unsigned long long)dma_addr);
+		dev_dbg(dev, " dma_addr = %pad\n", &dma_addr);
 
 		desc->dptr_low = lower_32_bits(dma_addr);
 		desc->dptr_high = upper_32_bits(dma_addr);

drivers/i2c/busses/i2c-meson.c

@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/types.h>
 
@@ -57,6 +58,10 @@ enum {
 	STATE_WRITE,
 };
 
+struct meson_i2c_data {
+	unsigned char div_factor;
+};
+
 /**
  * struct meson_i2c - Meson I2C device private data
  *
@@ -64,7 +69,6 @@ enum {
  * @dev:	Pointer to device structure
  * @regs:	Base address of the device memory mapped registers
  * @clk:	Pointer to clock structure
- * @irq:	IRQ number
  * @msg:	Pointer to the current I2C message
  * @state:	Current state in the driver state machine
  * @last:	Flag set for the last message in the transfer
@@ -75,6 +79,7 @@ enum {
  * @done:	Completion used to wait for transfer termination
  * @tokens:	Sequence of tokens to be written to the device
  * @num_tokens:	Number of tokens
+ * @data:	Pointer to the controlller's platform data
  */
 struct meson_i2c {
 	struct i2c_adapter	adap;
@@ -93,6 +98,8 @@ struct meson_i2c {
 	struct completion	done;
 	u32			tokens[2];
 	int			num_tokens;
+
+	const struct meson_i2c_data *data;
 };
 
 static void meson_i2c_set_mask(struct meson_i2c *i2c, int reg, u32 mask,
@@ -128,7 +135,7 @@ static void meson_i2c_set_clk_div(struct meson_i2c *i2c, unsigned int freq)
 	unsigned long clk_rate = clk_get_rate(i2c->clk);
 	unsigned int div;
 
-	div = DIV_ROUND_UP(clk_rate, freq * 4);
+	div = DIV_ROUND_UP(clk_rate, freq * i2c->data->div_factor);
 
 	/* clock divider has 12 bits */
 	if (div >= (1 << 12)) {
@@ -376,6 +383,9 @@ static int meson_i2c_probe(struct platform_device *pdev)
 	spin_lock_init(&i2c->lock);
 	init_completion(&i2c->done);
 
+	i2c->data = (const struct meson_i2c_data *)
+		of_device_get_match_data(&pdev->dev);
+
 	i2c->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(i2c->clk)) {
 		dev_err(&pdev->dev, "can't get device clock\n");
@@ -440,11 +450,25 @@ static int meson_i2c_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct meson_i2c_data i2c_meson6_data = {
+	.div_factor = 4,
+};
+
+static const struct meson_i2c_data i2c_gxbb_data = {
+	.div_factor = 4,
+};
+
+static const struct meson_i2c_data i2c_axg_data = {
+	.div_factor = 3,
+};
+
 static const struct of_device_id meson_i2c_match[] = {
-	{ .compatible = "amlogic,meson6-i2c" },
-	{ .compatible = "amlogic,meson-gxbb-i2c" },
-	{ },
+	{ .compatible = "amlogic,meson6-i2c", .data = &i2c_meson6_data },
+	{ .compatible = "amlogic,meson-gxbb-i2c", .data = &i2c_gxbb_data },
+	{ .compatible = "amlogic,meson-axg-i2c", .data = &i2c_axg_data },
+	{},
 };
+
 MODULE_DEVICE_TABLE(of, meson_i2c_match);
 
 static struct platform_driver meson_i2c_driver = {

drivers/i2c/busses/i2c-mpc.c

@@ -78,9 +78,7 @@ struct mpc_i2c_divider {
 };
 
 struct mpc_i2c_data {
-	void (*setup)(struct device_node *node, struct mpc_i2c *i2c,
-		      u32 clock, u32 prescaler);
-	u32 prescaler;
+	void (*setup)(struct device_node *node, struct mpc_i2c *i2c, u32 clock);
 };
 
 static inline void writeccr(struct mpc_i2c *i2c, u32 x)
@@ -201,7 +199,7 @@ static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
 };
 
 static int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
-					  int prescaler, u32 *real_clk)
+					  u32 *real_clk)
 {
 	const struct mpc_i2c_divider *div = NULL;
 	unsigned int pvr = mfspr(SPRN_PVR);
@@ -236,7 +234,7 @@ static int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
 
 static void mpc_i2c_setup_52xx(struct device_node *node,
 					 struct mpc_i2c *i2c,
-					 u32 clock, u32 prescaler)
+					 u32 clock)
 {
 	int ret, fdr;
 
@@ -246,7 +244,7 @@ static void mpc_i2c_setup_52xx(struct device_node *node,
 		return;
 	}
 
-	ret = mpc_i2c_get_fdr_52xx(node, clock, prescaler, &i2c->real_clk);
+	ret = mpc_i2c_get_fdr_52xx(node, clock, &i2c->real_clk);
 	fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
 
 	writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
@@ -258,7 +256,7 @@ static void mpc_i2c_setup_52xx(struct device_node *node,
 #else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
 static void mpc_i2c_setup_52xx(struct device_node *node,
 					 struct mpc_i2c *i2c,
-					 u32 clock, u32 prescaler)
+					 u32 clock)
 {
 }
 #endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
@@ -266,7 +264,7 @@ static void mpc_i2c_setup_52xx(struct device_node *node,
 #ifdef CONFIG_PPC_MPC512x
 static void mpc_i2c_setup_512x(struct device_node *node,
 					 struct mpc_i2c *i2c,
-					 u32 clock, u32 prescaler)
+					 u32 clock)
 {
 	struct device_node *node_ctrl;
 	void __iomem *ctrl;
@@ -289,12 +287,12 @@ static void mpc_i2c_setup_512x(struct device_node *node,
 	}
 
 	/* The clock setup for the 52xx works also fine for the 512x */
-	mpc_i2c_setup_52xx(node, i2c, clock, prescaler);
+	mpc_i2c_setup_52xx(node, i2c, clock);
 }
 #else /* CONFIG_PPC_MPC512x */
 static void mpc_i2c_setup_512x(struct device_node *node,
 					 struct mpc_i2c *i2c,
-					 u32 clock, u32 prescaler)
+					 u32 clock)
 {
 }
 #endif /* CONFIG_PPC_MPC512x */
@@ -332,14 +330,18 @@ static u32 mpc_i2c_get_sec_cfg_8xxx(void)
 		if (prop) {
 			/*
 			 * Map and check POR Device Status Register 2
-			 * (PORDEVSR2) at 0xE0014
+			 * (PORDEVSR2) at 0xE0014. Note than while MPC8533
+			 * and MPC8544 indicate SEC frequency ratio
+			 * configuration as bit 26 in PORDEVSR2, other MPC8xxx
+			 * parts may store it differently or may not have it
+			 * at all.
 			 */
 			reg = ioremap(get_immrbase() + *prop + 0x14, 0x4);
 			if (!reg)
 				printk(KERN_ERR
 				       "Error: couldn't map PORDEVSR2\n");
 			else
-				val = in_be32(reg) & 0x00000080; /* sec-cfg */
+				val = in_be32(reg) & 0x00000020; /* sec-cfg */
 			iounmap(reg);
 		}
 	}
@@ -350,7 +352,11 @@ static u32 mpc_i2c_get_sec_cfg_8xxx(void)
 
 static u32 mpc_i2c_get_prescaler_8xxx(void)
 {
-	/* mpc83xx and mpc82xx all have prescaler 1 */
+	/*
+	 * According to the AN2919 all MPC824x have prescaler 1, while MPC83xx
+	 * may have prescaler 1, 2, or 3, depending on the power-on
+	 * configuration.
+	 */
 	u32 prescaler = 1;
 
 	/* mpc85xx */
@@ -367,6 +373,10 @@ static u32 mpc_i2c_get_prescaler_8xxx(void)
 			|| (SVR_SOC_VER(svr) == SVR_8610))
 			/* the above 85xx SoCs have prescaler 1 */
 			prescaler = 1;
+		else if ((SVR_SOC_VER(svr) == SVR_8533)
+			|| (SVR_SOC_VER(svr) == SVR_8544))
+			/* the above 85xx SoCs have prescaler 3 or 2 */
+			prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
 		else
 			/* all the other 85xx have prescaler 2 */
 			prescaler = 2;
@@ -376,9 +386,10 @@ static u32 mpc_i2c_get_prescaler_8xxx(void)
 }
 
 static int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
-					  u32 prescaler, u32 *real_clk)
+					  u32 *real_clk)
 {
 	const struct mpc_i2c_divider *div = NULL;
+	u32 prescaler = mpc_i2c_get_prescaler_8xxx();
 	u32 divider;
 	int i;
 
@@ -388,12 +399,6 @@ static int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
 		return -EINVAL;
 	}
 
-	/* Determine proper divider value */
-	if (of_device_is_compatible(node, "fsl,mpc8544-i2c"))
-		prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
-	if (!prescaler)
-		prescaler = mpc_i2c_get_prescaler_8xxx();
-
 	divider = fsl_get_sys_freq() / clock / prescaler;
 
 	pr_debug("I2C: src_clock=%d clock=%d divider=%d\n",
@@ -415,7 +420,7 @@ static int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
 
 static void mpc_i2c_setup_8xxx(struct device_node *node,
 					 struct mpc_i2c *i2c,
-					 u32 clock, u32 prescaler)
+					 u32 clock)
 {
 	int ret, fdr;
 
@@ -426,7 +431,7 @@ static void mpc_i2c_setup_8xxx(struct device_node *node,
 		return;
 	}
 
-	ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler, &i2c->real_clk);
+	ret = mpc_i2c_get_fdr_8xxx(node, clock, &i2c->real_clk);
 	fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
 
 	writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR);
@@ -440,7 +445,7 @@ static void mpc_i2c_setup_8xxx(struct device_node *node,
 #else /* !CONFIG_FSL_SOC */
 static void mpc_i2c_setup_8xxx(struct device_node *node,
 					 struct mpc_i2c *i2c,
-					 u32 clock, u32 prescaler)
+					 u32 clock)
 {
 }
 #endif /* CONFIG_FSL_SOC */
@@ -711,11 +716,11 @@ static int fsl_i2c_probe(struct platform_device *op)
 
 	if (match->data) {
 		const struct mpc_i2c_data *data = match->data;
-		data->setup(op->dev.of_node, i2c, clock, data->prescaler);
+		data->setup(op->dev.of_node, i2c, clock);
 	} else {
 		/* Backwards compatibility */
 		if (of_get_property(op->dev.of_node, "dfsrr", NULL))
-			mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock, 0);
+			mpc_i2c_setup_8xxx(op->dev.of_node, i2c, clock);
 	}
 
 	prop = of_get_property(op->dev.of_node, "fsl,timeout", &plen);
@@ -813,12 +818,10 @@ static const struct mpc_i2c_data mpc_i2c_data_8313 = {
 
 static const struct mpc_i2c_data mpc_i2c_data_8543 = {
 	.setup = mpc_i2c_setup_8xxx,
-	.prescaler = 2,
 };
 
 static const struct mpc_i2c_data mpc_i2c_data_8544 = {
 	.setup = mpc_i2c_setup_8xxx,
-	.prescaler = 3,
 };
 
 static const struct of_device_id mpc_i2c_of_match[] = {

drivers/i2c/busses/i2c-mt65xx.c

@@ -61,6 +61,7 @@
 #define I2C_DMA_HARD_RST		0x0002
 #define I2C_DMA_4G_MODE			0x0001
 
+#define I2C_DEFAULT_CLK_DIV		5
 #define I2C_DEFAULT_SPEED		100000	/* hz */
 #define MAX_FS_MODE_SPEED		400000
 #define MAX_HS_MODE_SPEED		3400000
@@ -127,6 +128,7 @@ enum I2C_REGS_OFFSET {
 	OFFSET_DEBUGSTAT = 0x64,
 	OFFSET_DEBUGCTRL = 0x68,
 	OFFSET_TRANSFER_LEN_AUX = 0x6c,
+	OFFSET_CLOCK_DIV = 0x70,
 };
 
 struct mtk_i2c_compatible {
@@ -136,6 +138,7 @@ struct mtk_i2c_compatible {
 	unsigned char auto_restart: 1;
 	unsigned char aux_len_reg: 1;
 	unsigned char support_33bits: 1;
+	unsigned char timing_adjust: 1;
 };
 
 struct mtk_i2c {
@@ -176,6 +179,15 @@ static const struct i2c_adapter_quirks mt7622_i2c_quirks = {
 	.max_num_msgs = 255,
 };
 
+static const struct mtk_i2c_compatible mt2712_compat = {
+	.pmic_i2c = 0,
+	.dcm = 1,
+	.auto_restart = 1,
+	.aux_len_reg = 1,
+	.support_33bits = 1,
+	.timing_adjust = 1,
+};
+
 static const struct mtk_i2c_compatible mt6577_compat = {
 	.quirks = &mt6577_i2c_quirks,
 	.pmic_i2c = 0,
@@ -183,6 +195,7 @@ static const struct mtk_i2c_compatible mt6577_compat = {
 	.auto_restart = 0,
 	.aux_len_reg = 0,
 	.support_33bits = 0,
+	.timing_adjust = 0,
 };
 
 static const struct mtk_i2c_compatible mt6589_compat = {
@@ -192,6 +205,7 @@ static const struct mtk_i2c_compatible mt6589_compat = {
 	.auto_restart = 0,
 	.aux_len_reg = 0,
 	.support_33bits = 0,
+	.timing_adjust = 0,
 };
 
 static const struct mtk_i2c_compatible mt7622_compat = {
@@ -201,6 +215,7 @@ static const struct mtk_i2c_compatible mt7622_compat = {
 	.auto_restart = 1,
 	.aux_len_reg = 1,
 	.support_33bits = 0,
+	.timing_adjust = 0,
 };
 
 static const struct mtk_i2c_compatible mt8173_compat = {
@@ -209,9 +224,11 @@ static const struct mtk_i2c_compatible mt8173_compat = {
 	.auto_restart = 1,
 	.aux_len_reg = 1,
 	.support_33bits = 1,
+	.timing_adjust = 0,
 };
 
 static const struct of_device_id mtk_i2c_of_match[] = {
+	{ .compatible = "mediatek,mt2712-i2c", .data = &mt2712_compat },
 	{ .compatible = "mediatek,mt6577-i2c", .data = &mt6577_compat },
 	{ .compatible = "mediatek,mt6589-i2c", .data = &mt6589_compat },
 	{ .compatible = "mediatek,mt7622-i2c", .data = &mt7622_compat },
@@ -271,6 +288,9 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 	if (i2c->dev_comp->dcm)
 		writew(I2C_DCM_DISABLE, i2c->base + OFFSET_DCM_EN);
 
+	if (i2c->dev_comp->timing_adjust)
+		writew(I2C_DEFAULT_CLK_DIV - 1, i2c->base + OFFSET_CLOCK_DIV);
+
 	writew(i2c->timing_reg, i2c->base + OFFSET_TIMING);
 	writew(i2c->high_speed_reg, i2c->base + OFFSET_HS);
 
@@ -725,10 +745,6 @@ static int mtk_i2c_probe(struct platform_device *pdev)
 	if (!i2c)
 		return -ENOMEM;
 
-	ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c);
-	if (ret)
-		return -EINVAL;
-
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	i2c->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(i2c->base))
@@ -759,6 +775,13 @@ static int mtk_i2c_probe(struct platform_device *pdev)
 	i2c->adap.timeout = 2 * HZ;
 	i2c->adap.retries = 1;
 
+	ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c);
+	if (ret)
+		return -EINVAL;
+
+	if (i2c->dev_comp->timing_adjust)
+		i2c->clk_src_div *= I2C_DEFAULT_CLK_DIV;
+
 	if (i2c->have_pmic && !i2c->dev_comp->pmic_i2c)
 		return -EINVAL;
 
@@ -838,10 +861,19 @@ static int mtk_i2c_remove(struct platform_device *pdev)
 #ifdef CONFIG_PM_SLEEP
 static int mtk_i2c_resume(struct device *dev)
 {
+	int ret;
 	struct mtk_i2c *i2c = dev_get_drvdata(dev);
 
+	ret = mtk_i2c_clock_enable(i2c);
+	if (ret) {
+		dev_err(dev, "clock enable failed!\n");
+		return ret;
+	}
+
 	mtk_i2c_init_hw(i2c);
 
+	mtk_i2c_clock_disable(i2c);
+
 	return 0;
 }
 #endif

drivers/i2c/busses/i2c-mv64xxx.c

@@ -135,6 +135,7 @@ struct mv64xxx_i2c_data {
 	u32			freq_m;
 	u32			freq_n;
 	struct clk              *clk;
+	struct clk              *reg_clk;
 	wait_queue_head_t	waitq;
 	spinlock_t		lock;
 	struct i2c_msg		*msg;
@@ -894,13 +895,20 @@ mv64xxx_i2c_probe(struct platform_device *pd)
 	init_waitqueue_head(&drv_data->waitq);
 	spin_lock_init(&drv_data->lock);
 
-	/* Not all platforms have a clk */
+	/* Not all platforms have clocks */
 	drv_data->clk = devm_clk_get(&pd->dev, NULL);
 	if (IS_ERR(drv_data->clk) && PTR_ERR(drv_data->clk) == -EPROBE_DEFER)
 		return -EPROBE_DEFER;
 	if (!IS_ERR(drv_data->clk))
 		clk_prepare_enable(drv_data->clk);
 
+	drv_data->reg_clk = devm_clk_get(&pd->dev, "reg");
+	if (IS_ERR(drv_data->reg_clk) &&
+	    PTR_ERR(drv_data->reg_clk) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+	if (!IS_ERR(drv_data->reg_clk))
+		clk_prepare_enable(drv_data->reg_clk);
+
 	drv_data->irq = platform_get_irq(pd, 0);
 
 	if (pdata) {
@@ -950,8 +958,7 @@ mv64xxx_i2c_probe(struct platform_device *pd)
 exit_reset:
 	reset_control_assert(drv_data->rstc);
 exit_clk:
-	/* Not all platforms have a clk */
-	if (!IS_ERR(drv_data->clk))
+	clk_disable_unprepare(drv_data->reg_clk);
 	clk_disable_unprepare(drv_data->clk);
 
 	return rc;
@@ -965,8 +972,7 @@ mv64xxx_i2c_remove(struct platform_device *dev)
 	i2c_del_adapter(&drv_data->adapter);
 	free_irq(drv_data->irq, drv_data);
 	reset_control_assert(drv_data->rstc);
-	/* Not all platforms have a clk */
-	if (!IS_ERR(drv_data->clk))
+	clk_disable_unprepare(drv_data->reg_clk);
 	clk_disable_unprepare(drv_data->clk);
 
 	return 0;

drivers/i2c/busses/i2c-mxs.c

@@ -181,7 +181,7 @@ static int mxs_i2c_dma_setup_xfer(struct i2c_adapter *adap,
 	struct mxs_i2c_dev *i2c = i2c_get_adapdata(adap);
 
 	if (msg->flags & I2C_M_RD) {
-		i2c->dma_read = 1;
+		i2c->dma_read = true;
 		i2c->addr_data = (msg->addr << 1) | I2C_SMBUS_READ;
 
 		/*
@@ -239,7 +239,7 @@ static int mxs_i2c_dma_setup_xfer(struct i2c_adapter *adap,
 			goto read_init_dma_fail;
 		}
 	} else {
-		i2c->dma_read = 0;
+		i2c->dma_read = false;
 		i2c->addr_data = (msg->addr << 1) | I2C_SMBUS_WRITE;
 
 		/*

drivers/i2c/busses/i2c-rcar.c

@@ -62,7 +62,7 @@
 #define MIE	(1 << 3)	/* master if enable */
 #define TSBE	(1 << 2)
 #define FSB	(1 << 1)	/* force stop bit */
-#define ESG	(1 << 0)	/* en startbit gen */
+#define ESG	(1 << 0)	/* enable start bit gen */
 
 /* ICSSR (also for ICSIER) */
 #define GCAR	(1 << 6)	/* general call received */
@@ -132,6 +132,7 @@ struct rcar_i2c_priv {
 	int pos;
 	u32 icccr;
 	u32 flags;
+	u8 recovery_icmcr;	/* protected by adapter lock */
 	enum rcar_i2c_type devtype;
 	struct i2c_client *slave;
 
@@ -158,6 +159,46 @@ static u32 rcar_i2c_read(struct rcar_i2c_priv *priv, int reg)
 	return readl(priv->io + reg);
 }
 
+static int rcar_i2c_get_scl(struct i2c_adapter *adap)
+{
+	struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
+
+	return !!(rcar_i2c_read(priv, ICMCR) & FSCL);
+
+};
+
+static void rcar_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+	struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
+
+	if (val)
+		priv->recovery_icmcr |= FSCL;
+	else
+		priv->recovery_icmcr &= ~FSCL;
+
+	rcar_i2c_write(priv, ICMCR, priv->recovery_icmcr);
+};
+
+/* No get_sda, because the HW only reports its bus free logic, not SDA itself */
+
+static void rcar_i2c_set_sda(struct i2c_adapter *adap, int val)
+{
+	struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
+
+	if (val)
+		priv->recovery_icmcr |= FSDA;
+	else
+		priv->recovery_icmcr &= ~FSDA;
+
+	rcar_i2c_write(priv, ICMCR, priv->recovery_icmcr);
+};
+
+static struct i2c_bus_recovery_info rcar_i2c_bri = {
+	.get_scl = rcar_i2c_get_scl,
+	.set_scl = rcar_i2c_set_scl,
+	.set_sda = rcar_i2c_set_sda,
+	.recover_bus = i2c_generic_scl_recovery,
+};
 static void rcar_i2c_init(struct rcar_i2c_priv *priv)
 {
 	/* reset master mode */
@@ -170,7 +211,7 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv)
 
 static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
 {
-	int i;
+	int i, ret;
 
 	for (i = 0; i < LOOP_TIMEOUT; i++) {
 		/* make sure that bus is not busy */
@@ -179,7 +220,15 @@ static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
 		udelay(1);
 	}
 
-	return -EBUSY;
+	/* Waiting did not help, try to recover */
+	priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL;
+	ret = i2c_recover_bus(&priv->adap);
+
+	/* No failure when recovering, so check bus busy bit again */
+	if (ret == 0)
+		ret = (rcar_i2c_read(priv, ICMCR) & FSDA) ? -EBUSY : 0;
+
+	return ret;
 }
 
 static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, struct i2c_timings *t)
@@ -282,7 +331,7 @@ static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
 
 	rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | read);
 	/*
-	 * We don't have a testcase but the HW engineers say that the write order
+	 * We don't have a test case but the HW engineers say that the write order
 	 * of ICMSR and ICMCR depends on whether we issue START or REP_START. Since
 	 * it didn't cause a drawback for me, let's rather be safe than sorry.
 	 */
@@ -359,7 +408,7 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv)
 	int len;
 
 	/* Do not use DMA if it's not available or for messages < 8 bytes */
-	if (IS_ERR(chan) || msg->len < 8)
+	if (IS_ERR(chan) || msg->len < 8 || !(msg->flags & I2C_M_DMA_SAFE))
 		return;
 
 	if (read) {
@@ -440,7 +489,7 @@ static void rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
 
 		/*
 		 * Try to use DMA to transmit the rest of the data if
-		 * address transfer pashe just finished.
+		 * address transfer phase just finished.
 		 */
 		if (msr & MAT)
 			rcar_i2c_dma(priv);
@@ -851,6 +900,7 @@ static int rcar_i2c_probe(struct platform_device *pdev)
 	adap->retries = 3;
 	adap->dev.parent = dev;
 	adap->dev.of_node = dev->of_node;
+	adap->bus_recovery_info = &rcar_i2c_bri;
 	i2c_set_adapdata(adap, priv);
 	strlcpy(adap->name, pdev->name, sizeof(adap->name));
 

drivers/i2c/busses/i2c-rk3x.c

@@ -161,6 +161,7 @@ enum rk3x_i2c_state {
 };
 
 /**
+ * struct rk3x_i2c_soc_data:
  * @grf_offset: offset inside the grf regmap for setting the i2c type
  * @calc_timings: Callback function for i2c timing information calculated
  */
@@ -194,7 +195,7 @@ struct rk3x_i2c_soc_data {
 struct rk3x_i2c {
 	struct i2c_adapter adap;
 	struct device *dev;
-	struct rk3x_i2c_soc_data *soc_data;
+	const struct rk3x_i2c_soc_data *soc_data;
 
 	/* Hardware resources */
 	void __iomem *regs;
@@ -1164,27 +1165,27 @@ static const struct rk3x_i2c_soc_data rk3399_soc_data = {
 static const struct of_device_id rk3x_i2c_match[] = {
 	{
 		.compatible = "rockchip,rv1108-i2c",
-		.data = (void *)&rv1108_soc_data
+		.data = &rv1108_soc_data
 	},
 	{
 		.compatible = "rockchip,rk3066-i2c",
-		.data = (void *)&rk3066_soc_data
+		.data = &rk3066_soc_data
 	},
 	{
 		.compatible = "rockchip,rk3188-i2c",
-		.data = (void *)&rk3188_soc_data
+		.data = &rk3188_soc_data
 	},
 	{
 		.compatible = "rockchip,rk3228-i2c",
-		.data = (void *)&rk3228_soc_data
+		.data = &rk3228_soc_data
 	},
 	{
 		.compatible = "rockchip,rk3288-i2c",
-		.data = (void *)&rk3288_soc_data
+		.data = &rk3288_soc_data
 	},
 	{
 		.compatible = "rockchip,rk3399-i2c",
-		.data = (void *)&rk3399_soc_data
+		.data = &rk3399_soc_data
 	},
 	{},
 };
@@ -1207,7 +1208,7 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	match = of_match_node(rk3x_i2c_match, np);
-	i2c->soc_data = (struct rk3x_i2c_soc_data *)match->data;
+	i2c->soc_data = match->data;
 
 	/* use common interface to get I2C timing properties */
 	i2c_parse_fw_timings(&pdev->dev, &i2c->t, true);

drivers/i2c/busses/i2c-sh_mobile.c

@@ -113,7 +113,6 @@ enum sh_mobile_i2c_op {
 	OP_TX_FIRST,
 	OP_TX,
 	OP_TX_STOP,
-	OP_TX_STOP_DATA,
 	OP_TX_TO_RX,
 	OP_RX,
 	OP_RX_STOP,
@@ -145,11 +144,12 @@ struct sh_mobile_i2c_data {
 	struct dma_chan *dma_rx;
 	struct scatterlist sg;
 	enum dma_data_direction dma_direction;
+	u8 *dma_buf;
 };
 
 struct sh_mobile_dt_config {
 	int clks_per_count;
-	void (*setup)(struct sh_mobile_i2c_data *pd);
+	int (*setup)(struct sh_mobile_i2c_data *pd);
 };
 
 #define IIC_FLAG_HAS_ICIC67	(1 << 0)
@@ -246,36 +246,10 @@ static u32 sh_mobile_i2c_icch(unsigned long count_khz, u32 tHIGH, u32 tf)
 	return (((count_khz * (tHIGH + tf)) + 5000) / 10000);
 }
 
-static int sh_mobile_i2c_init(struct sh_mobile_i2c_data *pd)
+static int sh_mobile_i2c_check_timing(struct sh_mobile_i2c_data *pd)
 {
-	unsigned long i2c_clk_khz;
-	u32 tHIGH, tLOW, tf;
-	uint16_t max_val;
-
-	/* Get clock rate after clock is enabled */
-	clk_prepare_enable(pd->clk);
-	i2c_clk_khz = clk_get_rate(pd->clk) / 1000;
-	clk_disable_unprepare(pd->clk);
-	i2c_clk_khz /= pd->clks_per_count;
+	u16 max_val = pd->flags & IIC_FLAG_HAS_ICIC67 ? 0x1ff : 0xff;
 
-	if (pd->bus_speed == STANDARD_MODE) {
-		tLOW	= 47;	/* tLOW = 4.7 us */
-		tHIGH	= 40;	/* tHD;STA = tHIGH = 4.0 us */
-		tf	= 3;	/* tf = 0.3 us */
-	} else if (pd->bus_speed == FAST_MODE) {
-		tLOW	= 13;	/* tLOW = 1.3 us */
-		tHIGH	= 6;	/* tHD;STA = tHIGH = 0.6 us */
-		tf	= 3;	/* tf = 0.3 us */
-	} else {
-		dev_err(pd->dev, "unrecognized bus speed %lu Hz\n",
-			pd->bus_speed);
-		return -EINVAL;
-	}
-
-	pd->iccl = sh_mobile_i2c_iccl(i2c_clk_khz, tLOW, tf);
-	pd->icch = sh_mobile_i2c_icch(i2c_clk_khz, tHIGH, tf);
-
-	max_val = pd->flags & IIC_FLAG_HAS_ICIC67 ? 0x1ff : 0xff;
 	if (pd->iccl > max_val || pd->icch > max_val) {
 		dev_err(pd->dev, "timing values out of range: L/H=0x%x/0x%x\n",
 			pd->iccl, pd->icch);
@@ -298,35 +272,43 @@ static int sh_mobile_i2c_init(struct sh_mobile_i2c_data *pd)
 	return 0;
 }
 
-static void activate_ch(struct sh_mobile_i2c_data *pd)
+static int sh_mobile_i2c_init(struct sh_mobile_i2c_data *pd)
 {
-	/* Wake up device and enable clock */
-	pm_runtime_get_sync(pd->dev);
-	clk_prepare_enable(pd->clk);
+	unsigned long i2c_clk_khz;
+	u32 tHIGH, tLOW, tf;
 
-	/* Enable channel and configure rx ack */
-	iic_set_clr(pd, ICCR, ICCR_ICE, 0);
+	i2c_clk_khz = clk_get_rate(pd->clk) / 1000 / pd->clks_per_count;
+
+	if (pd->bus_speed == STANDARD_MODE) {
+		tLOW	= 47;	/* tLOW = 4.7 us */
+		tHIGH	= 40;	/* tHD;STA = tHIGH = 4.0 us */
+		tf	= 3;	/* tf = 0.3 us */
+	} else if (pd->bus_speed == FAST_MODE) {
+		tLOW	= 13;	/* tLOW = 1.3 us */
+		tHIGH	= 6;	/* tHD;STA = tHIGH = 0.6 us */
+		tf	= 3;	/* tf = 0.3 us */
+	} else {
+		dev_err(pd->dev, "unrecognized bus speed %lu Hz\n",
+			pd->bus_speed);
+		return -EINVAL;
+	}
 
-	/* Mask all interrupts */
-	iic_wr(pd, ICIC, 0);
+	pd->iccl = sh_mobile_i2c_iccl(i2c_clk_khz, tLOW, tf);
+	pd->icch = sh_mobile_i2c_icch(i2c_clk_khz, tHIGH, tf);
 
-	/* Set the clock */
-	iic_wr(pd, ICCL, pd->iccl & 0xff);
-	iic_wr(pd, ICCH, pd->icch & 0xff);
+	return sh_mobile_i2c_check_timing(pd);
 }
 
-static void deactivate_ch(struct sh_mobile_i2c_data *pd)
+static int sh_mobile_i2c_v2_init(struct sh_mobile_i2c_data *pd)
 {
-	/* Clear/disable interrupts */
-	iic_wr(pd, ICSR, 0);
-	iic_wr(pd, ICIC, 0);
+	unsigned long clks_per_cycle;
 
-	/* Disable channel */
-	iic_set_clr(pd, ICCR, 0, ICCR_ICE);
+	/* L = 5, H = 4, L + H = 9 */
+	clks_per_cycle = clk_get_rate(pd->clk) / pd->bus_speed;
+	pd->iccl = DIV_ROUND_UP(clks_per_cycle * 5 / 9 - 1, pd->clks_per_count);
+	pd->icch = DIV_ROUND_UP(clks_per_cycle * 4 / 9 - 5, pd->clks_per_count);
 
-	/* Disable clock and mark device as idle */
-	clk_disable_unprepare(pd->clk);
-	pm_runtime_put_sync(pd->dev);
+	return sh_mobile_i2c_check_timing(pd);
 }
 
 static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
@@ -350,10 +332,7 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
 	case OP_TX: /* write data */
 		iic_wr(pd, ICDR, data);
 		break;
-	case OP_TX_STOP_DATA: /* write data and issue a stop afterwards */
-		iic_wr(pd, ICDR, data);
-		/* fallthrough */
-	case OP_TX_STOP: /* issue a stop */
+	case OP_TX_STOP: /* issue a stop (or rep_start) */
 		iic_wr(pd, ICCR, pd->send_stop ? ICCR_ICE | ICCR_TRS
 					       : ICCR_ICE | ICCR_TRS | ICCR_BBSY);
 		break;
@@ -387,11 +366,6 @@ static bool sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd)
 	return pd->pos == -1;
 }
 
-static bool sh_mobile_i2c_is_last_byte(struct sh_mobile_i2c_data *pd)
-{
-	return pd->pos == pd->msg->len - 1;
-}
-
 static void sh_mobile_i2c_get_data(struct sh_mobile_i2c_data *pd,
 				   unsigned char *buf)
 {
@@ -409,20 +383,12 @@ static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd)
 	unsigned char data;
 
 	if (pd->pos == pd->msg->len) {
-		/* Send stop if we haven't yet (DMA case) */
-		if (pd->send_stop && pd->stop_after_dma)
 		i2c_op(pd, OP_TX_STOP, 0);
 		return 1;
 	}
 
 	sh_mobile_i2c_get_data(pd, &data);
-
-	if (sh_mobile_i2c_is_last_byte(pd))
-		i2c_op(pd, OP_TX_STOP_DATA, data);
-	else if (sh_mobile_i2c_is_first_byte(pd))
-		i2c_op(pd, OP_TX_FIRST, data);
-	else
-		i2c_op(pd, OP_TX, data);
+	i2c_op(pd, sh_mobile_i2c_is_first_byte(pd) ? OP_TX_FIRST : OP_TX, data);
 
 	pd->pos++;
 	return 0;
@@ -464,8 +430,9 @@ static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
 				break;
 			}
 			data = i2c_op(pd, OP_RX_STOP_DATA, 0);
-		} else
+		} else if (real_pos >= 0) {
 			data = i2c_op(pd, OP_RX, 0);
+		}
 
 		if (real_pos >= 0)
 			pd->msg->buf[real_pos] = data;
@@ -548,6 +515,8 @@ static void sh_mobile_i2c_dma_callback(void *data)
 	pd->pos = pd->msg->len;
 	pd->stop_after_dma = true;
 
+	i2c_release_dma_safe_msg_buf(pd->msg, pd->dma_buf);
+
 	iic_set_clr(pd, ICIC, 0, ICIC_TDMAE | ICIC_RDMAE);
 }
 
@@ -608,7 +577,7 @@ static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd)
 	if (IS_ERR(chan))
 		return;
 
-	dma_addr = dma_map_single(chan->device->dev, pd->msg->buf, pd->msg->len, dir);
+	dma_addr = dma_map_single(chan->device->dev, pd->dma_buf, pd->msg->len, dir);
 	if (dma_mapping_error(chan->device->dev, dma_addr)) {
 		dev_dbg(pd->dev, "dma map failed, using PIO\n");
 		return;
@@ -651,10 +620,10 @@ static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
 
 	if (do_init) {
 		/* Initialize channel registers */
-		iic_set_clr(pd, ICCR, 0, ICCR_ICE);
+		iic_wr(pd, ICCR, ICCR_SCP);
 
 		/* Enable channel and configure rx ack */
-		iic_set_clr(pd, ICCR, ICCR_ICE, 0);
+		iic_wr(pd, ICCR, ICCR_ICE | ICCR_SCP);
 
 		/* Set the clock */
 		iic_wr(pd, ICCL, pd->iccl & 0xff);
@@ -665,7 +634,8 @@ static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
 	pd->pos = -1;
 	pd->sr = 0;
 
-	if (pd->msg->len > 8)
+	pd->dma_buf = i2c_get_dma_safe_msg_buf(pd->msg, 8);
+	if (pd->dma_buf)
 		sh_mobile_i2c_xfer_dma(pd);
 
 	/* Enable all interrupts to begin with */
@@ -731,7 +701,8 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
 	int i;
 	long timeout;
 
-	activate_ch(pd);
+	/* Wake up device and enable clock */
+	pm_runtime_get_sync(pd->dev);
 
 	/* Process all messages */
 	for (i = 0; i < num; i++) {
@@ -768,11 +739,13 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
 			break;
 	}
 
-	deactivate_ch(pd);
+	/* Disable channel */
+	iic_wr(pd, ICCR, ICCR_SCP);
+
+	/* Disable clock and mark device as idle */
+	pm_runtime_put_sync(pd->dev);
 
-	if (!err)
-		err = num;
-	return err;
+	return err ?: num;
 }
 
 static u32 sh_mobile_i2c_func(struct i2c_adapter *adapter)
@@ -789,7 +762,7 @@ static const struct i2c_algorithm sh_mobile_i2c_algorithm = {
  * r8a7740 chip has lasting errata on I2C I/O pad reset.
  * this is work-around for it.
  */
-static void sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd)
+static int sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd)
 {
 	iic_set_clr(pd, ICCR, ICCR_ICE, 0);
 	iic_rd(pd, ICCR); /* dummy read */
@@ -810,14 +783,23 @@ static void sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd)
 	udelay(10);
 	iic_wr(pd, ICCR, ICCR_TRS);
 	udelay(10);
+
+	return sh_mobile_i2c_init(pd);
 }
 
 static const struct sh_mobile_dt_config default_dt_config = {
 	.clks_per_count = 1,
+	.setup = sh_mobile_i2c_init,
 };
 
 static const struct sh_mobile_dt_config fast_clock_dt_config = {
 	.clks_per_count = 2,
+	.setup = sh_mobile_i2c_init,
+};
+
+static const struct sh_mobile_dt_config v2_freq_calc_dt_config = {
+	.clks_per_count = 2,
+	.setup = sh_mobile_i2c_v2_init,
 };
 
 static const struct sh_mobile_dt_config r8a7740_dt_config = {
@@ -828,7 +810,7 @@ static const struct sh_mobile_dt_config r8a7740_dt_config = {
 static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
 	{ .compatible = "renesas,iic-r8a73a4", .data = &fast_clock_dt_config },
 	{ .compatible = "renesas,iic-r8a7740", .data = &r8a7740_dt_config },
-	{ .compatible = "renesas,iic-r8a7790", .data = &fast_clock_dt_config },
+	{ .compatible = "renesas,iic-r8a7790", .data = &v2_freq_calc_dt_config },
 	{ .compatible = "renesas,iic-r8a7791", .data = &fast_clock_dt_config },
 	{ .compatible = "renesas,iic-r8a7792", .data = &fast_clock_dt_config },
 	{ .compatible = "renesas,iic-r8a7793", .data = &fast_clock_dt_config },
@@ -910,32 +892,13 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
 		return PTR_ERR(pd->reg);
 
 	ret = of_property_read_u32(dev->dev.of_node, "clock-frequency", &bus_speed);
-	pd->bus_speed = ret ? STANDARD_MODE : bus_speed;
+	pd->bus_speed = (ret || !bus_speed) ? STANDARD_MODE : bus_speed;
 	pd->clks_per_count = 1;
 
-	config = of_device_get_match_data(&dev->dev);
-	if (config) {
-		pd->clks_per_count = config->clks_per_count;
-
-		if (config->setup)
-			config->setup(pd);
-	}
-
-	/* The IIC blocks on SH-Mobile ARM processors
-	 * come with two new bits in ICIC.
-	 */
+	/* Newer variants come with two new bits in ICIC */
 	if (resource_size(res) > 0x17)
 		pd->flags |= IIC_FLAG_HAS_ICIC67;
 
-	ret = sh_mobile_i2c_init(pd);
-	if (ret)
-		return ret;
-
-	/* Init DMA */
-	sg_init_table(&pd->sg, 1);
-	pd->dma_direction = DMA_NONE;
-	pd->dma_rx = pd->dma_tx = ERR_PTR(-EPROBE_DEFER);
-
 	/* Enable Runtime PM for this device.
 	 *
 	 * Also tell the Runtime PM core to ignore children
@@ -948,6 +911,24 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
 	 */
 	pm_suspend_ignore_children(&dev->dev, true);
 	pm_runtime_enable(&dev->dev);
+	pm_runtime_get_sync(&dev->dev);
+
+	config = of_device_get_match_data(&dev->dev);
+	if (config) {
+		pd->clks_per_count = config->clks_per_count;
+		ret = config->setup(pd);
+	} else {
+		ret = sh_mobile_i2c_init(pd);
+	}
+
+	pm_runtime_put_sync(&dev->dev);
+	if (ret)
+		return ret;
+
+	/* Init DMA */
+	sg_init_table(&pd->sg, 1);
+	pd->dma_direction = DMA_NONE;
+	pd->dma_rx = pd->dma_tx = ERR_PTR(-EPROBE_DEFER);
 
 	/* setup the private data */
 	adap = &pd->adap;

drivers/i2c/i2c-core-base.c

@@ -27,7 +27,7 @@
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/errno.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/i2c-smbus.h>
 #include <linux/idr.h>
@@ -134,52 +134,22 @@ static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 /* i2c bus recovery routines */
 static int get_scl_gpio_value(struct i2c_adapter *adap)
 {
-	return gpio_get_value(adap->bus_recovery_info->scl_gpio);
+	return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod);
 }
 
 static void set_scl_gpio_value(struct i2c_adapter *adap, int val)
 {
-	gpio_set_value(adap->bus_recovery_info->scl_gpio, val);
+	gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val);
 }
 
 static int get_sda_gpio_value(struct i2c_adapter *adap)
 {
-	return gpio_get_value(adap->bus_recovery_info->sda_gpio);
+	return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod);
 }
 
-static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap)
+static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
 {
-	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
-	struct device *dev = &adap->dev;
-	int ret = 0;
-
-	ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN |
-			GPIOF_OUT_INIT_HIGH, "i2c-scl");
-	if (ret) {
-		dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio);
-		return ret;
-	}
-
-	if (bri->get_sda) {
-		if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) {
-			/* work without SDA polling */
-			dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n",
-					bri->sda_gpio);
-			bri->get_sda = NULL;
-		}
-	}
-
-	return ret;
-}
-
-static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap)
-{
-	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
-
-	if (bri->get_sda)
-		gpio_free(bri->sda_gpio);
-
-	gpio_free(bri->scl_gpio);
+	gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val);
 }
 
 /*
@@ -190,7 +160,7 @@ static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap)
 #define RECOVERY_NDELAY		5000
 #define RECOVERY_CLK_CNT	9
 
-static int i2c_generic_recovery(struct i2c_adapter *adap)
+int i2c_generic_scl_recovery(struct i2c_adapter *adap)
 {
 	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
 	int i = 0, val = 1, ret = 0;
@@ -199,6 +169,8 @@ static int i2c_generic_recovery(struct i2c_adapter *adap)
 		bri->prepare_recovery(adap);
 
 	bri->set_scl(adap, val);
+	if (bri->set_sda)
+		bri->set_sda(adap, 1);
 	ndelay(RECOVERY_NDELAY);
 
 	/*
@@ -227,33 +199,25 @@ static int i2c_generic_recovery(struct i2c_adapter *adap)
 	if (bri->get_sda && !bri->get_sda(adap))
 		ret = -EBUSY;
 
+	/* If all went well, send STOP for a sane bus state. */
+	if (ret == 0 && bri->set_sda) {
+		bri->set_scl(adap, 0);
+		ndelay(RECOVERY_NDELAY / 2);
+		bri->set_sda(adap, 0);
+		ndelay(RECOVERY_NDELAY / 2);
+		bri->set_scl(adap, 1);
+		ndelay(RECOVERY_NDELAY / 2);
+		bri->set_sda(adap, 1);
+		ndelay(RECOVERY_NDELAY / 2);
+	}
+
 	if (bri->unprepare_recovery)
 		bri->unprepare_recovery(adap);
 
 	return ret;
 }
-
-int i2c_generic_scl_recovery(struct i2c_adapter *adap)
-{
-	return i2c_generic_recovery(adap);
-}
 EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
 
-int i2c_generic_gpio_recovery(struct i2c_adapter *adap)
-{
-	int ret;
-
-	ret = i2c_get_gpios_for_recovery(adap);
-	if (ret)
-		return ret;
-
-	ret = i2c_generic_recovery(adap);
-	i2c_put_gpios_for_recovery(adap);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(i2c_generic_gpio_recovery);
-
 int i2c_recover_bus(struct i2c_adapter *adap)
 {
 	if (!adap->bus_recovery_info)
@@ -277,21 +241,19 @@ static void i2c_init_recovery(struct i2c_adapter *adap)
 		goto err;
 	}
 
-	/* Generic GPIO recovery */
-	if (bri->recover_bus == i2c_generic_gpio_recovery) {
-		if (!gpio_is_valid(bri->scl_gpio)) {
-			err_str = "invalid SCL gpio";
-			goto err;
-		}
-
-		if (gpio_is_valid(bri->sda_gpio))
-			bri->get_sda = get_sda_gpio_value;
-		else
-			bri->get_sda = NULL;
-
+	if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) {
 		bri->get_scl = get_scl_gpio_value;
 		bri->set_scl = set_scl_gpio_value;
-	} else if (bri->recover_bus == i2c_generic_scl_recovery) {
+		if (bri->sda_gpiod) {
+			bri->get_sda = get_sda_gpio_value;
+			/* FIXME: add proper flag instead of '0' once available */
+			if (gpiod_get_direction(bri->sda_gpiod) == 0)
+				bri->set_sda = set_sda_gpio_value;
+		}
+		return;
+	}
+
+	if (bri->recover_bus == i2c_generic_scl_recovery) {
 		/* Generic SCL recovery */
 		if (!bri->set_scl || !bri->get_scl) {
 			err_str = "no {get|set}_scl() found";
@@ -1976,63 +1938,35 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 EXPORT_SYMBOL(i2c_transfer);
 
 /**
- * i2c_master_send - issue a single I2C message in master transmit mode
- * @client: Handle to slave device
- * @buf: Data that will be written to the slave
- * @count: How many bytes to write, must be less than 64k since msg.len is u16
- *
- * Returns negative errno, or else the number of bytes written.
- */
-int i2c_master_send(const struct i2c_client *client, const char *buf, int count)
-{
-	int ret;
-	struct i2c_adapter *adap = client->adapter;
-	struct i2c_msg msg;
-
-	msg.addr = client->addr;
-	msg.flags = client->flags & I2C_M_TEN;
-	msg.len = count;
-	msg.buf = (char *)buf;
-
-	ret = i2c_transfer(adap, &msg, 1);
-
-	/*
-	 * If everything went ok (i.e. 1 msg transmitted), return #bytes
-	 * transmitted, else error code.
-	 */
-	return (ret == 1) ? count : ret;
-}
-EXPORT_SYMBOL(i2c_master_send);
-
-/**
- * i2c_master_recv - issue a single I2C message in master receive mode
+ * i2c_transfer_buffer_flags - issue a single I2C message transferring data
+ *			       to/from a buffer
  * @client: Handle to slave device
- * @buf: Where to store data read from slave
- * @count: How many bytes to read, must be less than 64k since msg.len is u16
+ * @buf: Where the data is stored
+ * @count: How many bytes to transfer, must be less than 64k since msg.len is u16
+ * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads
  *
- * Returns negative errno, or else the number of bytes read.
+ * Returns negative errno, or else the number of bytes transferred.
  */
-int i2c_master_recv(const struct i2c_client *client, char *buf, int count)
+int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf,
+			      int count, u16 flags)
 {
-	struct i2c_adapter *adap = client->adapter;
-	struct i2c_msg msg;
 	int ret;
+	struct i2c_msg msg = {
+		.addr = client->addr,
+		.flags = flags | (client->flags & I2C_M_TEN),
+		.len = count,
+		.buf = buf,
+	};
 
-	msg.addr = client->addr;
-	msg.flags = client->flags & I2C_M_TEN;
-	msg.flags |= I2C_M_RD;
-	msg.len = count;
-	msg.buf = buf;
-
-	ret = i2c_transfer(adap, &msg, 1);
+	ret = i2c_transfer(client->adapter, &msg, 1);
 
 	/*
-	 * If everything went ok (i.e. 1 msg received), return #bytes received,
-	 * else error code.
+	 * If everything went ok (i.e. 1 msg transferred), return #bytes
+	 * transferred, else error code.
 	 */
 	return (ret == 1) ? count : ret;
 }
-EXPORT_SYMBOL(i2c_master_recv);
+EXPORT_SYMBOL(i2c_transfer_buffer_flags);
 
 /* ----------------------------------------------------
  * the i2c address scanning function
@@ -2265,6 +2199,52 @@ void i2c_put_adapter(struct i2c_adapter *adap)
 }
 EXPORT_SYMBOL(i2c_put_adapter);
 
+/**
+ * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg
+ * @msg: the message to be checked
+ * @threshold: the minimum number of bytes for which using DMA makes sense
+ *
+ * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO.
+ *	   Or a valid pointer to be used with DMA. After use, release it by
+ *	   calling i2c_release_dma_safe_msg_buf().
+ *
+ * This function must only be called from process context!
+ */
+u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold)
+{
+	if (msg->len < threshold)
+		return NULL;
+
+	if (msg->flags & I2C_M_DMA_SAFE)
+		return msg->buf;
+
+	pr_debug("using bounce buffer for addr=0x%02x, len=%d\n",
+		 msg->addr, msg->len);
+
+	if (msg->flags & I2C_M_RD)
+		return kzalloc(msg->len, GFP_KERNEL);
+	else
+		return kmemdup(msg->buf, msg->len, GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf);
+
+/**
+ * i2c_release_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg
+ * @msg: the message to be synced with
+ * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL.
+ */
+void i2c_release_dma_safe_msg_buf(struct i2c_msg *msg, u8 *buf)
+{
+	if (!buf || buf == msg->buf)
+		return;
+
+	if (msg->flags & I2C_M_RD)
+		memcpy(msg->buf, buf, msg->len);
+
+	kfree(buf);
+}
+EXPORT_SYMBOL_GPL(i2c_release_dma_safe_msg_buf);
+
 MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
 MODULE_DESCRIPTION("I2C-Bus main module");
 MODULE_LICENSE("GPL");

drivers/i2c/i2c-core-smbus.c

@@ -18,6 +18,7 @@
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/i2c-smbus.h>
+#include <linux/slab.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/smbus.h>
@@ -291,6 +292,22 @@ s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command,
 }
 EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
 
+static void i2c_smbus_try_get_dmabuf(struct i2c_msg *msg, u8 init_val)
+{
+	bool is_read = msg->flags & I2C_M_RD;
+	unsigned char *dma_buf;
+
+	dma_buf = kzalloc(I2C_SMBUS_BLOCK_MAX + (is_read ? 2 : 3), GFP_KERNEL);
+	if (!dma_buf)
+		return;
+
+	msg->buf = dma_buf;
+	msg->flags |= I2C_M_DMA_SAFE;
+
+	if (init_val)
+		msg->buf[0] = init_val;
+}
+
 /* Simulate a SMBus command using the i2c protocol
    No checking of parameters is done!  */
 static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
@@ -368,6 +385,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 			msg[1].flags |= I2C_M_RECV_LEN;
 			msg[1].len = 1; /* block length will be added by
 					   the underlying bus driver */
+			i2c_smbus_try_get_dmabuf(&msg[1], 0);
 		} else {
 			msg[0].len = data->block[0] + 2;
 			if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
@@ -376,8 +394,10 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 					data->block[0]);
 				return -EINVAL;
 			}
+
+			i2c_smbus_try_get_dmabuf(&msg[0], command);
 			for (i = 1; i < msg[0].len; i++)
-				msgbuf0[i] = data->block[i-1];
+				msg[0].buf[i] = data->block[i - 1];
 		}
 		break;
 	case I2C_SMBUS_BLOCK_PROC_CALL:
@@ -389,12 +409,16 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 				data->block[0]);
 			return -EINVAL;
 		}
+
 		msg[0].len = data->block[0] + 2;
+		i2c_smbus_try_get_dmabuf(&msg[0], command);
 		for (i = 1; i < msg[0].len; i++)
-			msgbuf0[i] = data->block[i-1];
+			msg[0].buf[i] = data->block[i - 1];
+
 		msg[1].flags |= I2C_M_RECV_LEN;
 		msg[1].len = 1; /* block length will be added by
 				   the underlying bus driver */
+		i2c_smbus_try_get_dmabuf(&msg[1], 0);
 		break;
 	case I2C_SMBUS_I2C_BLOCK_DATA:
 		if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
@@ -406,10 +430,13 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 
 		if (read_write == I2C_SMBUS_READ) {
 			msg[1].len = data->block[0];
+			i2c_smbus_try_get_dmabuf(&msg[1], 0);
 		} else {
 			msg[0].len = data->block[0] + 1;
+
+			i2c_smbus_try_get_dmabuf(&msg[0], command);
 			for (i = 1; i <= data->block[0]; i++)
-				msgbuf0[i] = data->block[i];
+				msg[0].buf[i] = data->block[i];
 		}
 		break;
 	default:
@@ -457,14 +484,20 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 			break;
 		case I2C_SMBUS_I2C_BLOCK_DATA:
 			for (i = 0; i < data->block[0]; i++)
-				data->block[i+1] = msgbuf1[i];
+				data->block[i + 1] = msg[1].buf[i];
 			break;
 		case I2C_SMBUS_BLOCK_DATA:
 		case I2C_SMBUS_BLOCK_PROC_CALL:
-			for (i = 0; i < msgbuf1[0] + 1; i++)
-				data->block[i] = msgbuf1[i];
+			for (i = 0; i < msg[1].buf[0] + 1; i++)
+				data->block[i] = msg[1].buf[i];
 			break;
 		}
+
+	if (msg[0].flags & I2C_M_DMA_SAFE)
+		kfree(msg[0].buf);
+	if (msg[1].flags & I2C_M_DMA_SAFE)
+		kfree(msg[1].buf);
+
 	return 0;
 }
 

drivers/i2c/i2c-dev.c

@@ -264,6 +264,8 @@ static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client,
 			res = PTR_ERR(msgs[i].buf);
 			break;
 		}
+		/* memdup_user allocates with GFP_KERNEL, so DMA is ok */
+		msgs[i].flags |= I2C_M_DMA_SAFE;
 
 		/*
 		 * If the message length is received from the slave (similar

drivers/i2c/muxes/Kconfig

@@ -64,11 +64,11 @@ config I2C_MUX_PCA9541
 	  will be called i2c-mux-pca9541.
 
 config I2C_MUX_PCA954x
-	tristate "Philips PCA954x I2C Mux/switches"
+	tristate "NXP PCA954x and PCA984x I2C Mux/switches"
 	depends on GPIOLIB || COMPILE_TEST
 	help
-	  If you say yes here you get support for the Philips PCA954x
-	  I2C mux/switch devices.
+	  If you say yes here you get support for the NXP PCA954x
+	  and PCA984x I2C mux/switch devices.
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-mux-pca954x.

drivers/i2c/muxes/i2c-mux-pca954x.c

@@ -4,11 +4,11 @@
  * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
  * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
  *
- * This module supports the PCA954x series of I2C multiplexer/switch chips
- * made by Philips Semiconductors.
+ * This module supports the PCA954x and PCA954x series of I2C multiplexer/switch
+ * chips made by NXP Semiconductors.
  * This includes the:
- *	 PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547
- *	 and PCA9548.
+ *	 PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547,
+ *	 PCA9548, PCA9846, PCA9847, PCA9848 and PCA9849.
  *
  * These chips are all controlled via the I2C bus itself, and all have a
  * single 8-bit register. The upstream "parent" bus fans out to two,
@@ -63,6 +63,10 @@ enum pca_type {
 	pca_9546,
 	pca_9547,
 	pca_9548,
+	pca_9846,
+	pca_9847,
+	pca_9848,
+	pca_9849,
 };
 
 struct chip_desc {
@@ -129,6 +133,24 @@ static const struct chip_desc chips[] = {
 		.nchans = 8,
 		.muxtype = pca954x_isswi,
 	},
+	[pca_9846] = {
+		.nchans = 4,
+		.muxtype = pca954x_isswi,
+	},
+	[pca_9847] = {
+		.nchans = 8,
+		.enable = 0x8,
+		.muxtype = pca954x_ismux,
+	},
+	[pca_9848] = {
+		.nchans = 8,
+		.muxtype = pca954x_isswi,
+	},
+	[pca_9849] = {
+		.nchans = 4,
+		.enable = 0x4,
+		.muxtype = pca954x_ismux,
+	},
 };
 
 static const struct i2c_device_id pca954x_id[] = {
@@ -140,6 +162,10 @@ static const struct i2c_device_id pca954x_id[] = {
 	{ "pca9546", pca_9546 },
 	{ "pca9547", pca_9547 },
 	{ "pca9548", pca_9548 },
+	{ "pca9846", pca_9846 },
+	{ "pca9847", pca_9847 },
+	{ "pca9848", pca_9848 },
+	{ "pca9849", pca_9849 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, pca954x_id);
@@ -154,6 +180,10 @@ static const struct of_device_id pca954x_of_match[] = {
 	{ .compatible = "nxp,pca9546", .data = &chips[pca_9546] },
 	{ .compatible = "nxp,pca9547", .data = &chips[pca_9547] },
 	{ .compatible = "nxp,pca9548", .data = &chips[pca_9548] },
+	{ .compatible = "nxp,pca9846", .data = &chips[pca_9846] },
+	{ .compatible = "nxp,pca9847", .data = &chips[pca_9847] },
+	{ .compatible = "nxp,pca9848", .data = &chips[pca_9848] },
+	{ .compatible = "nxp,pca9849", .data = &chips[pca_9849] },
 	{}
 };
 MODULE_DEVICE_TABLE(of, pca954x_of_match);

drivers/i2c/muxes/i2c-mux-reg.c

@@ -177,6 +177,9 @@ static int i2c_mux_reg_probe(struct platform_device *pdev)
 			sizeof(mux->data));
 	} else {
 		ret = i2c_mux_reg_probe_dt(mux, pdev);
+		if (ret == -EPROBE_DEFER)
+			return ret;
+
 		if (ret < 0) {
 			dev_err(&pdev->dev, "Error parsing device tree");
 			return ret;

drivers/misc/eeprom/Kconfig

@@ -4,6 +4,7 @@ config EEPROM_AT24
 	tristate "I2C EEPROMs / RAMs / ROMs from most vendors"
 	depends on I2C && SYSFS
 	select NVMEM
+	select REGMAP_I2C
 	help
 	  Enable this driver to get read/write support to most I2C EEPROMs
 	  and compatible devices like FRAMs, SRAMs, ROMs etc. After you

drivers/misc/eeprom/at24.c

@@ -24,8 +24,10 @@
 #include <linux/acpi.h>
 #include <linux/i2c.h>
 #include <linux/nvmem-provider.h>
+#include <linux/regmap.h>
 #include <linux/platform_data/at24.h>
 #include <linux/pm_runtime.h>
+#include <linux/gpio/consumer.h>
 
 /*
  * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable.
@@ -55,14 +57,13 @@
  * which won't work on pure SMBus systems.
  */
 
+struct at24_client {
+	struct i2c_client *client;
+	struct regmap *regmap;
+};
+
 struct at24_data {
 	struct at24_platform_data chip;
-	int use_smbus;
-	int use_smbus_write;
-
-	ssize_t (*read_func)(struct at24_data *, char *, unsigned int, size_t);
-	ssize_t (*write_func)(struct at24_data *,
-			      const char *, unsigned int, size_t);
 
 	/*
 	 * Lock protects against activities from other Linux tasks,
@@ -70,18 +71,20 @@ struct at24_data {
 	 */
 	struct mutex lock;
 
-	u8 *writebuf;
-	unsigned write_max;
-	unsigned num_addresses;
+	unsigned int write_max;
+	unsigned int num_addresses;
+	unsigned int offset_adj;
 
 	struct nvmem_config nvmem_config;
 	struct nvmem_device *nvmem;
 
+	struct gpio_desc *wp_gpio;
+
 	/*
 	 * Some chips tie up multiple I2C addresses; dummy devices reserve
 	 * them for us, and we'll use them with SMBus calls.
 	 */
-	struct i2c_client *client[];
+	struct at24_client client[];
 };
 
 /*
@@ -93,27 +96,17 @@ struct at24_data {
  *
  * This value is forced to be a power of two so that writes align on pages.
  */
-static unsigned io_limit = 128;
-module_param(io_limit, uint, 0);
-MODULE_PARM_DESC(io_limit, "Maximum bytes per I/O (default 128)");
+static unsigned int at24_io_limit = 128;
+module_param_named(io_limit, at24_io_limit, uint, 0);
+MODULE_PARM_DESC(at24_io_limit, "Maximum bytes per I/O (default 128)");
 
 /*
  * Specs often allow 5 msec for a page write, sometimes 20 msec;
  * it's important to recover from write timeouts.
  */
-static unsigned write_timeout = 25;
-module_param(write_timeout, uint, 0);
-MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)");
-
-#define AT24_SIZE_BYTELEN 5
-#define AT24_SIZE_FLAGS 8
-
-#define AT24_BITMASK(x) (BIT(x) - 1)
-
-/* create non-zero magic value for given eeprom parameters */
-#define AT24_DEVICE_MAGIC(_len, _flags) 		\
-	((1 << AT24_SIZE_FLAGS | (_flags)) 		\
-	    << AT24_SIZE_BYTELEN | ilog2(_len))
+static unsigned int at24_write_timeout = 25;
+module_param_named(write_timeout, at24_write_timeout, uint, 0);
+MODULE_PARM_DESC(at24_write_timeout, "Time (in ms) to try writes (default 25)");
 
 /*
  * Both reads and writes fail if the previous write didn't complete yet. This
@@ -126,118 +119,123 @@ MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)");
  * iteration of processing the request. Both should be unsigned integers
  * holding at least 32 bits.
  */
-#define loop_until_timeout(tout, op_time)				\
-	for (tout = jiffies + msecs_to_jiffies(write_timeout), op_time = 0; \
+#define at24_loop_until_timeout(tout, op_time)				\
+	for (tout = jiffies + msecs_to_jiffies(at24_write_timeout),	\
+	     op_time = 0;						\
 	     op_time ? time_before(op_time, tout) : true;		\
 	     usleep_range(1000, 1500), op_time = jiffies)
 
+struct at24_chip_data {
+	/*
+	 * these fields mirror their equivalents in
+	 * struct at24_platform_data
+	 */
+	u32 byte_len;
+	u8 flags;
+};
+
+#define AT24_CHIP_DATA(_name, _len, _flags)				\
+	static const struct at24_chip_data _name = {			\
+		.byte_len = _len, .flags = _flags,			\
+	}
+
+/* needs 8 addresses as A0-A2 are ignored */
+AT24_CHIP_DATA(at24_data_24c00, 128 / 8, AT24_FLAG_TAKE8ADDR);
+/* old variants can't be handled with this generic entry! */
+AT24_CHIP_DATA(at24_data_24c01, 1024 / 8, 0);
+AT24_CHIP_DATA(at24_data_24cs01, 16,
+	AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
+AT24_CHIP_DATA(at24_data_24c02, 2048 / 8, 0);
+AT24_CHIP_DATA(at24_data_24cs02, 16,
+	AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
+AT24_CHIP_DATA(at24_data_24mac402, 48 / 8,
+	AT24_FLAG_MAC | AT24_FLAG_READONLY);
+AT24_CHIP_DATA(at24_data_24mac602, 64 / 8,
+	AT24_FLAG_MAC | AT24_FLAG_READONLY);
+/* spd is a 24c02 in memory DIMMs */
+AT24_CHIP_DATA(at24_data_spd, 2048 / 8,
+	AT24_FLAG_READONLY | AT24_FLAG_IRUGO);
+AT24_CHIP_DATA(at24_data_24c04, 4096 / 8, 0);
+AT24_CHIP_DATA(at24_data_24cs04, 16,
+	AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
+/* 24rf08 quirk is handled at i2c-core */
+AT24_CHIP_DATA(at24_data_24c08, 8192 / 8, 0);
+AT24_CHIP_DATA(at24_data_24cs08, 16,
+	AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
+AT24_CHIP_DATA(at24_data_24c16, 16384 / 8, 0);
+AT24_CHIP_DATA(at24_data_24cs16, 16,
+	AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
+AT24_CHIP_DATA(at24_data_24c32, 32768 / 8, AT24_FLAG_ADDR16);
+AT24_CHIP_DATA(at24_data_24cs32, 16,
+	AT24_FLAG_ADDR16 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
+AT24_CHIP_DATA(at24_data_24c64, 65536 / 8, AT24_FLAG_ADDR16);
+AT24_CHIP_DATA(at24_data_24cs64, 16,
+	AT24_FLAG_ADDR16 | AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
+AT24_CHIP_DATA(at24_data_24c128, 131072 / 8, AT24_FLAG_ADDR16);
+AT24_CHIP_DATA(at24_data_24c256, 262144 / 8, AT24_FLAG_ADDR16);
+AT24_CHIP_DATA(at24_data_24c512, 524288 / 8, AT24_FLAG_ADDR16);
+AT24_CHIP_DATA(at24_data_24c1024, 1048576 / 8, AT24_FLAG_ADDR16);
+/* identical to 24c08 ? */
+AT24_CHIP_DATA(at24_data_INT3499, 8192 / 8, 0);
+
 static const struct i2c_device_id at24_ids[] = {
-	/* needs 8 addresses as A0-A2 are ignored */
-	{ "24c00",	AT24_DEVICE_MAGIC(128 / 8,	AT24_FLAG_TAKE8ADDR) },
-	/* old variants can't be handled with this generic entry! */
-	{ "24c01",	AT24_DEVICE_MAGIC(1024 / 8,	0) },
-	{ "24cs01",	AT24_DEVICE_MAGIC(16,
-				AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
-	{ "24c02",	AT24_DEVICE_MAGIC(2048 / 8,	0) },
-	{ "24cs02",	AT24_DEVICE_MAGIC(16,
-				AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
-	{ "24mac402",	AT24_DEVICE_MAGIC(48 / 8,
-				AT24_FLAG_MAC | AT24_FLAG_READONLY) },
-	{ "24mac602",	AT24_DEVICE_MAGIC(64 / 8,
-				AT24_FLAG_MAC | AT24_FLAG_READONLY) },
-	/* spd is a 24c02 in memory DIMMs */
-	{ "spd",	AT24_DEVICE_MAGIC(2048 / 8,
-				AT24_FLAG_READONLY | AT24_FLAG_IRUGO) },
-	{ "24c04",	AT24_DEVICE_MAGIC(4096 / 8,	0) },
-	{ "24cs04",	AT24_DEVICE_MAGIC(16,
-				AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
-	/* 24rf08 quirk is handled at i2c-core */
-	{ "24c08",	AT24_DEVICE_MAGIC(8192 / 8,	0) },
-	{ "24cs08",	AT24_DEVICE_MAGIC(16,
-				AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
-	{ "24c16",	AT24_DEVICE_MAGIC(16384 / 8,	0) },
-	{ "24cs16",	AT24_DEVICE_MAGIC(16,
-				AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
-	{ "24c32",	AT24_DEVICE_MAGIC(32768 / 8,	AT24_FLAG_ADDR16) },
-	{ "24cs32",	AT24_DEVICE_MAGIC(16,
-				AT24_FLAG_ADDR16 |
-				AT24_FLAG_SERIAL |
-				AT24_FLAG_READONLY) },
-	{ "24c64",	AT24_DEVICE_MAGIC(65536 / 8,	AT24_FLAG_ADDR16) },
-	{ "24cs64",	AT24_DEVICE_MAGIC(16,
-				AT24_FLAG_ADDR16 |
-				AT24_FLAG_SERIAL |
-				AT24_FLAG_READONLY) },
-	{ "24c128",	AT24_DEVICE_MAGIC(131072 / 8,	AT24_FLAG_ADDR16) },
-	{ "24c256",	AT24_DEVICE_MAGIC(262144 / 8,	AT24_FLAG_ADDR16) },
-	{ "24c512",	AT24_DEVICE_MAGIC(524288 / 8,	AT24_FLAG_ADDR16) },
-	{ "24c1024",	AT24_DEVICE_MAGIC(1048576 / 8,	AT24_FLAG_ADDR16) },
+	{ "24c00",	(kernel_ulong_t)&at24_data_24c00 },
+	{ "24c01",	(kernel_ulong_t)&at24_data_24c01 },
+	{ "24cs01",	(kernel_ulong_t)&at24_data_24cs01 },
+	{ "24c02",	(kernel_ulong_t)&at24_data_24c02 },
+	{ "24cs02",	(kernel_ulong_t)&at24_data_24cs02 },
+	{ "24mac402",	(kernel_ulong_t)&at24_data_24mac402 },
+	{ "24mac602",	(kernel_ulong_t)&at24_data_24mac602 },
+	{ "spd",	(kernel_ulong_t)&at24_data_spd },
+	{ "24c04",	(kernel_ulong_t)&at24_data_24c04 },
+	{ "24cs04",	(kernel_ulong_t)&at24_data_24cs04 },
+	{ "24c08",	(kernel_ulong_t)&at24_data_24c08 },
+	{ "24cs08",	(kernel_ulong_t)&at24_data_24cs08 },
+	{ "24c16",	(kernel_ulong_t)&at24_data_24c16 },
+	{ "24cs16",	(kernel_ulong_t)&at24_data_24cs16 },
+	{ "24c32",	(kernel_ulong_t)&at24_data_24c32 },
+	{ "24cs32",	(kernel_ulong_t)&at24_data_24cs32 },
+	{ "24c64",	(kernel_ulong_t)&at24_data_24c64 },
+	{ "24cs64",	(kernel_ulong_t)&at24_data_24cs64 },
+	{ "24c128",	(kernel_ulong_t)&at24_data_24c128 },
+	{ "24c256",	(kernel_ulong_t)&at24_data_24c256 },
+	{ "24c512",	(kernel_ulong_t)&at24_data_24c512 },
+	{ "24c1024",	(kernel_ulong_t)&at24_data_24c1024 },
 	{ "at24",	0 },
 	{ /* END OF LIST */ }
 };
 MODULE_DEVICE_TABLE(i2c, at24_ids);
 
 static const struct of_device_id at24_of_match[] = {
-	{
-		.compatible = "atmel,24c00",
-		.data = (void *)AT24_DEVICE_MAGIC(128 / 8, AT24_FLAG_TAKE8ADDR)
-	},
-	{
-		.compatible = "atmel,24c01",
-		.data = (void *)AT24_DEVICE_MAGIC(1024 / 8, 0)
-	},
-	{
-		.compatible = "atmel,24c02",
-		.data = (void *)AT24_DEVICE_MAGIC(2048 / 8, 0)
-	},
-	{
-		.compatible = "atmel,spd",
-		.data = (void *)AT24_DEVICE_MAGIC(2048 / 8,
-				AT24_FLAG_READONLY | AT24_FLAG_IRUGO)
-	},
-	{
-		.compatible = "atmel,24c04",
-		.data = (void *)AT24_DEVICE_MAGIC(4096 / 8, 0)
-	},
-	{
-		.compatible = "atmel,24c08",
-		.data = (void *)AT24_DEVICE_MAGIC(8192 / 8, 0)
-	},
-	{
-		.compatible = "atmel,24c16",
-		.data = (void *)AT24_DEVICE_MAGIC(16384 / 8, 0)
-	},
-	{
-		.compatible = "atmel,24c32",
-		.data = (void *)AT24_DEVICE_MAGIC(32768 / 8, AT24_FLAG_ADDR16)
-	},
-	{
-		.compatible = "atmel,24c64",
-		.data = (void *)AT24_DEVICE_MAGIC(65536 / 8, AT24_FLAG_ADDR16)
-	},
-	{
-		.compatible = "atmel,24c128",
-		.data = (void *)AT24_DEVICE_MAGIC(131072 / 8, AT24_FLAG_ADDR16)
-	},
-	{
-		.compatible = "atmel,24c256",
-		.data = (void *)AT24_DEVICE_MAGIC(262144 / 8, AT24_FLAG_ADDR16)
-	},
-	{
-		.compatible = "atmel,24c512",
-		.data = (void *)AT24_DEVICE_MAGIC(524288 / 8, AT24_FLAG_ADDR16)
-	},
-	{
-		.compatible = "atmel,24c1024",
-		.data = (void *)AT24_DEVICE_MAGIC(1048576 / 8, AT24_FLAG_ADDR16)
-	},
-	{ },
+	{ .compatible = "atmel,24c00",		.data = &at24_data_24c00 },
+	{ .compatible = "atmel,24c01",		.data = &at24_data_24c01 },
+	{ .compatible = "atmel,24cs01",		.data = &at24_data_24cs01 },
+	{ .compatible = "atmel,24c02",		.data = &at24_data_24c02 },
+	{ .compatible = "atmel,24cs02",		.data = &at24_data_24cs02 },
+	{ .compatible = "atmel,24mac402",	.data = &at24_data_24mac402 },
+	{ .compatible = "atmel,24mac602",	.data = &at24_data_24mac602 },
+	{ .compatible = "atmel,spd",		.data = &at24_data_spd },
+	{ .compatible = "atmel,24c04",		.data = &at24_data_24c04 },
+	{ .compatible = "atmel,24cs04",		.data = &at24_data_24cs04 },
+	{ .compatible = "atmel,24c08",		.data = &at24_data_24c08 },
+	{ .compatible = "atmel,24cs08",		.data = &at24_data_24cs08 },
+	{ .compatible = "atmel,24c16",		.data = &at24_data_24c16 },
+	{ .compatible = "atmel,24cs16",		.data = &at24_data_24cs16 },
+	{ .compatible = "atmel,24c32",		.data = &at24_data_24c32 },
+	{ .compatible = "atmel,24cs32",		.data = &at24_data_24cs32 },
+	{ .compatible = "atmel,24c64",		.data = &at24_data_24c64 },
+	{ .compatible = "atmel,24cs64",		.data = &at24_data_24cs64 },
+	{ .compatible = "atmel,24c128",		.data = &at24_data_24c128 },
+	{ .compatible = "atmel,24c256",		.data = &at24_data_24c256 },
+	{ .compatible = "atmel,24c512",		.data = &at24_data_24c512 },
+	{ .compatible = "atmel,24c1024",	.data = &at24_data_24c1024 },
+	{ /* END OF LIST */ },
 };
 MODULE_DEVICE_TABLE(of, at24_of_match);
 
 static const struct acpi_device_id at24_acpi_ids[] = {
-	{ "INT3499", AT24_DEVICE_MAGIC(8192 / 8, 0) },
-	{ }
+	{ "INT3499",	(kernel_ulong_t)&at24_data_INT3499 },
+	{ /* END OF LIST */ }
 };
 MODULE_DEVICE_TABLE(acpi, at24_acpi_ids);
 
@@ -251,20 +249,11 @@ MODULE_DEVICE_TABLE(acpi, at24_acpi_ids);
  * Slave address and byte offset derive from the offset. Always
  * set the byte address; on a multi-master board, another master
  * may have changed the chip's "current" address pointer.
- *
- * REVISIT some multi-address chips don't rollover page reads to
- * the next slave address, so we may need to truncate the count.
- * Those chips might need another quirk flag.
- *
- * If the real hardware used four adjacent 24c02 chips and that
- * were misconfigured as one 24c08, that would be a similar effect:
- * one "eeprom" file not four, but larger reads would fail when
- * they crossed certain pages.
  */
-static struct i2c_client *at24_translate_offset(struct at24_data *at24,
+static struct at24_client *at24_translate_offset(struct at24_data *at24,
 						 unsigned int *offset)
 {
-	unsigned i;
+	unsigned int i;
 
 	if (at24->chip.flags & AT24_FLAG_ADDR16) {
 		i = *offset >> 16;
@@ -274,168 +263,55 @@ static struct i2c_client *at24_translate_offset(struct at24_data *at24,
 		*offset &= 0xff;
 	}
 
-	return at24->client[i];
-}
-
-static ssize_t at24_eeprom_read_smbus(struct at24_data *at24, char *buf,
-				      unsigned int offset, size_t count)
-{
-	unsigned long timeout, read_time;
-	struct i2c_client *client;
-	int status;
-
-	client = at24_translate_offset(at24, &offset);
-
-	if (count > io_limit)
-		count = io_limit;
-
-	/* Smaller eeproms can work given some SMBus extension calls */
-	if (count > I2C_SMBUS_BLOCK_MAX)
-		count = I2C_SMBUS_BLOCK_MAX;
-
-	loop_until_timeout(timeout, read_time) {
-		status = i2c_smbus_read_i2c_block_data_or_emulated(client,
-								   offset,
-								   count, buf);
-
-		dev_dbg(&client->dev, "read %zu@%d --> %d (%ld)\n",
-				count, offset, status, jiffies);
-
-		if (status == count)
-			return count;
-	}
-
-	return -ETIMEDOUT;
-}
-
-static ssize_t at24_eeprom_read_i2c(struct at24_data *at24, char *buf,
-				    unsigned int offset, size_t count)
-{
-	unsigned long timeout, read_time;
-	struct i2c_client *client;
-	struct i2c_msg msg[2];
-	int status, i;
-	u8 msgbuf[2];
-
-	memset(msg, 0, sizeof(msg));
-	client = at24_translate_offset(at24, &offset);
-
-	if (count > io_limit)
-		count = io_limit;
-
-	/*
-	 * When we have a better choice than SMBus calls, use a combined I2C
-	 * message. Write address; then read up to io_limit data bytes. Note
-	 * that read page rollover helps us here (unlike writes). msgbuf is
-	 * u8 and will cast to our needs.
-	 */
-	i = 0;
-	if (at24->chip.flags & AT24_FLAG_ADDR16)
-		msgbuf[i++] = offset >> 8;
-	msgbuf[i++] = offset;
-
-	msg[0].addr = client->addr;
-	msg[0].buf = msgbuf;
-	msg[0].len = i;
-
-	msg[1].addr = client->addr;
-	msg[1].flags = I2C_M_RD;
-	msg[1].buf = buf;
-	msg[1].len = count;
-
-	loop_until_timeout(timeout, read_time) {
-		status = i2c_transfer(client->adapter, msg, 2);
-		if (status == 2)
-			status = count;
-
-		dev_dbg(&client->dev, "read %zu@%d --> %d (%ld)\n",
-				count, offset, status, jiffies);
-
-		if (status == count)
-			return count;
-	}
-
-	return -ETIMEDOUT;
+	return &at24->client[i];
 }
 
-static ssize_t at24_eeprom_read_serial(struct at24_data *at24, char *buf,
+static size_t at24_adjust_read_count(struct at24_data *at24,
 				      unsigned int offset, size_t count)
 {
-	unsigned long timeout, read_time;
-	struct i2c_client *client;
-	struct i2c_msg msg[2];
-	u8 addrbuf[2];
-	int status;
-
-	client = at24_translate_offset(at24, &offset);
+	unsigned int bits;
+	size_t remainder;
 
-	memset(msg, 0, sizeof(msg));
-	msg[0].addr = client->addr;
-	msg[0].buf = addrbuf;
-
-	/*
-	 * The address pointer of the device is shared between the regular
-	 * EEPROM array and the serial number block. The dummy write (part of
-	 * the sequential read protocol) ensures the address pointer is reset
-	 * to the desired position.
-	 */
-	if (at24->chip.flags & AT24_FLAG_ADDR16) {
-		/*
-		 * For 16 bit address pointers, the word address must contain
-		 * a '10' sequence in bits 11 and 10 regardless of the
-		 * intended position of the address pointer.
-		 */
-		addrbuf[0] = 0x08;
-		addrbuf[1] = offset;
-		msg[0].len = 2;
-	} else {
 	/*
-		 * Otherwise the word address must begin with a '10' sequence,
-		 * regardless of the intended address.
+	 * In case of multi-address chips that don't rollover reads to
+	 * the next slave address: truncate the count to the slave boundary,
+	 * so that the read never straddles slaves.
 	 */
-		addrbuf[0] = 0x80 + offset;
-		msg[0].len = 1;
+	if (at24->chip.flags & AT24_FLAG_NO_RDROL) {
+		bits = (at24->chip.flags & AT24_FLAG_ADDR16) ? 16 : 8;
+		remainder = BIT(bits) - offset;
+		if (count > remainder)
+			count = remainder;
 	}
 
-	msg[1].addr = client->addr;
-	msg[1].flags = I2C_M_RD;
-	msg[1].buf = buf;
-	msg[1].len = count;
+	if (count > at24_io_limit)
+		count = at24_io_limit;
 
-	loop_until_timeout(timeout, read_time) {
-		status = i2c_transfer(client->adapter, msg, 2);
-		if (status == 2)
 	return count;
-	}
-
-	return -ETIMEDOUT;
 }
 
-static ssize_t at24_eeprom_read_mac(struct at24_data *at24, char *buf,
+static ssize_t at24_regmap_read(struct at24_data *at24, char *buf,
 				unsigned int offset, size_t count)
 {
 	unsigned long timeout, read_time;
+	struct at24_client *at24_client;
 	struct i2c_client *client;
-	struct i2c_msg msg[2];
-	u8 addrbuf[2];
-	int status;
+	struct regmap *regmap;
+	int ret;
 
-	client = at24_translate_offset(at24, &offset);
+	at24_client = at24_translate_offset(at24, &offset);
+	regmap = at24_client->regmap;
+	client = at24_client->client;
+	count = at24_adjust_read_count(at24, offset, count);
 
-	memset(msg, 0, sizeof(msg));
-	msg[0].addr = client->addr;
-	msg[0].buf = addrbuf;
-	/* EUI-48 starts from 0x9a, EUI-64 from 0x98 */
-	addrbuf[0] = 0xa0 - at24->chip.byte_len + offset;
-	msg[0].len = 1;
-	msg[1].addr = client->addr;
-	msg[1].flags = I2C_M_RD;
-	msg[1].buf = buf;
-	msg[1].len = count;
-
-	loop_until_timeout(timeout, read_time) {
-		status = i2c_transfer(client->adapter, msg, 2);
-		if (status == 2)
+	/* adjust offset for mac and serial read ops */
+	offset += at24->offset_adj;
+
+	at24_loop_until_timeout(timeout, read_time) {
+		ret = regmap_bulk_read(regmap, offset, buf, count);
+		dev_dbg(&client->dev, "read %zu@%d --> %d (%ld)\n",
+			count, offset, ret, jiffies);
+		if (!ret)
 			return count;
 	}
 
@@ -454,7 +330,7 @@ static ssize_t at24_eeprom_read_mac(struct at24_data *at24, char *buf,
 static size_t at24_adjust_write_count(struct at24_data *at24,
 				      unsigned int offset, size_t count)
 {
-	unsigned next_page;
+	unsigned int next_page;
 
 	/* write_max is at most a page */
 	if (count > at24->write_max)
@@ -468,91 +344,25 @@ static size_t at24_adjust_write_count(struct at24_data *at24,
 	return count;
 }
 
-static ssize_t at24_eeprom_write_smbus_block(struct at24_data *at24,
-					     const char *buf,
-					     unsigned int offset, size_t count)
-{
-	unsigned long timeout, write_time;
-	struct i2c_client *client;
-	ssize_t status = 0;
-
-	client = at24_translate_offset(at24, &offset);
-	count = at24_adjust_write_count(at24, offset, count);
-
-	loop_until_timeout(timeout, write_time) {
-		status = i2c_smbus_write_i2c_block_data(client,
-							offset, count, buf);
-		if (status == 0)
-			status = count;
-
-		dev_dbg(&client->dev, "write %zu@%d --> %zd (%ld)\n",
-				count, offset, status, jiffies);
-
-		if (status == count)
-			return count;
-	}
-
-	return -ETIMEDOUT;
-}
-
-static ssize_t at24_eeprom_write_smbus_byte(struct at24_data *at24,
-					    const char *buf,
-					    unsigned int offset, size_t count)
-{
-	unsigned long timeout, write_time;
-	struct i2c_client *client;
-	ssize_t status = 0;
-
-	client = at24_translate_offset(at24, &offset);
-
-	loop_until_timeout(timeout, write_time) {
-		status = i2c_smbus_write_byte_data(client, offset, buf[0]);
-		if (status == 0)
-			status = count;
-
-		dev_dbg(&client->dev, "write %zu@%d --> %zd (%ld)\n",
-				count, offset, status, jiffies);
-
-		if (status == count)
-			return count;
-	}
-
-	return -ETIMEDOUT;
-}
-
-static ssize_t at24_eeprom_write_i2c(struct at24_data *at24, const char *buf,
+static ssize_t at24_regmap_write(struct at24_data *at24, const char *buf,
 				 unsigned int offset, size_t count)
 {
 	unsigned long timeout, write_time;
+	struct at24_client *at24_client;
 	struct i2c_client *client;
-	struct i2c_msg msg;
-	ssize_t status = 0;
-	int i = 0;
+	struct regmap *regmap;
+	int ret;
 
-	client = at24_translate_offset(at24, &offset);
+	at24_client = at24_translate_offset(at24, &offset);
+	regmap = at24_client->regmap;
+	client = at24_client->client;
 	count = at24_adjust_write_count(at24, offset, count);
 
-	msg.addr = client->addr;
-	msg.flags = 0;
-
-	/* msg.buf is u8 and casts will mask the values */
-	msg.buf = at24->writebuf;
-	if (at24->chip.flags & AT24_FLAG_ADDR16)
-		msg.buf[i++] = offset >> 8;
-
-	msg.buf[i++] = offset;
-	memcpy(&msg.buf[i], buf, count);
-	msg.len = i + count;
-
-	loop_until_timeout(timeout, write_time) {
-		status = i2c_transfer(client->adapter, &msg, 1);
-		if (status == 1)
-			status = count;
-
-		dev_dbg(&client->dev, "write %zu@%d --> %zd (%ld)\n",
-				count, offset, status, jiffies);
-
-		if (status == count)
+	at24_loop_until_timeout(timeout, write_time) {
+		ret = regmap_bulk_write(regmap, offset, buf, count);
+		dev_dbg(&client->dev, "write %zu@%d --> %d (%ld)\n",
+			count, offset, ret, jiffies);
+		if (!ret)
 			return count;
 	}
 
@@ -562,7 +372,7 @@ static ssize_t at24_eeprom_write_i2c(struct at24_data *at24, const char *buf,
 static int at24_read(void *priv, unsigned int off, void *val, size_t count)
 {
 	struct at24_data *at24 = priv;
-	struct device *dev = &at24->client[0]->dev;
+	struct device *dev = &at24->client[0].client->dev;
 	char *buf = val;
 	int ret;
 
@@ -587,7 +397,7 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count)
 	while (count) {
 		int	status;
 
-		status = at24->read_func(at24, buf, off, count);
+		status = at24_regmap_read(at24, buf, off, count);
 		if (status < 0) {
 			mutex_unlock(&at24->lock);
 			pm_runtime_put(dev);
@@ -608,7 +418,7 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count)
 static int at24_write(void *priv, unsigned int off, void *val, size_t count)
 {
 	struct at24_data *at24 = priv;
-	struct device *dev = &at24->client[0]->dev;
+	struct device *dev = &at24->client[0].client->dev;
 	char *buf = val;
 	int ret;
 
@@ -629,12 +439,14 @@ static int at24_write(void *priv, unsigned int off, void *val, size_t count)
 	 * from this host, but not from other I2C masters.
 	 */
 	mutex_lock(&at24->lock);
+	gpiod_set_value_cansleep(at24->wp_gpio, 0);
 
 	while (count) {
 		int status;
 
-		status = at24->write_func(at24, buf, off, count);
+		status = at24_regmap_write(at24, buf, off, count);
 		if (status < 0) {
+			gpiod_set_value_cansleep(at24->wp_gpio, 1);
 			mutex_unlock(&at24->lock);
 			pm_runtime_put(dev);
 			return status;
@@ -644,6 +456,7 @@ static int at24_write(void *priv, unsigned int off, void *val, size_t count)
 		count -= status;
 	}
 
+	gpiod_set_value_cansleep(at24->wp_gpio, 1);
 	mutex_unlock(&at24->lock);
 
 	pm_runtime_put(dev);
@@ -658,6 +471,8 @@ static void at24_get_pdata(struct device *dev, struct at24_platform_data *chip)
 
 	if (device_property_present(dev, "read-only"))
 		chip->flags |= AT24_FLAG_READONLY;
+	if (device_property_present(dev, "no-read-rollover"))
+		chip->flags |= AT24_FLAG_NO_RDROL;
 
 	err = device_property_read_u32(dev, "size", &val);
 	if (!err)
@@ -676,16 +491,38 @@ static void at24_get_pdata(struct device *dev, struct at24_platform_data *chip)
 	}
 }
 
+static unsigned int at24_get_offset_adj(u8 flags, unsigned int byte_len)
+{
+	if (flags & AT24_FLAG_MAC) {
+		/* EUI-48 starts from 0x9a, EUI-64 from 0x98 */
+		return 0xa0 - byte_len;
+	} else if (flags & AT24_FLAG_SERIAL && flags & AT24_FLAG_ADDR16) {
+		/*
+		 * For 16 bit address pointers, the word address must contain
+		 * a '10' sequence in bits 11 and 10 regardless of the
+		 * intended position of the address pointer.
+		 */
+		return 0x0800;
+	} else if (flags & AT24_FLAG_SERIAL) {
+		/*
+		 * Otherwise the word address must begin with a '10' sequence,
+		 * regardless of the intended address.
+		 */
+		return 0x0080;
+	} else {
+		return 0;
+	}
+}
+
 static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
-	struct at24_platform_data chip;
-	kernel_ulong_t magic = 0;
+	struct at24_platform_data chip = { 0 };
+	const struct at24_chip_data *cd = NULL;
 	bool writable;
-	int use_smbus = 0;
-	int use_smbus_write = 0;
 	struct at24_data *at24;
 	int err;
-	unsigned i, num_addresses;
+	unsigned int i, num_addresses;
+	struct regmap_config regmap_config = { };
 	u8 test_byte;
 
 	if (client->dev.platform_data) {
@@ -698,28 +535,22 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		 */
 		if (client->dev.of_node &&
 		    of_match_device(at24_of_match, &client->dev)) {
-			magic = (kernel_ulong_t)
-				of_device_get_match_data(&client->dev);
+			cd = of_device_get_match_data(&client->dev);
 		} else if (id) {
-			magic = id->driver_data;
+			cd = (void *)id->driver_data;
 		} else {
 			const struct acpi_device_id *aid;
 
 			aid = acpi_match_device(at24_acpi_ids, &client->dev);
 			if (aid)
-				magic = aid->driver_data;
+				cd = (void *)aid->driver_data;
 		}
-		if (!magic)
+		if (!cd)
 			return -ENODEV;
 
-		chip.byte_len = BIT(magic & AT24_BITMASK(AT24_SIZE_BYTELEN));
-		magic >>= AT24_SIZE_BYTELEN;
-		chip.flags = magic & AT24_BITMASK(AT24_SIZE_FLAGS);
-
+		chip.byte_len = cd->byte_len;
+		chip.flags = cd->flags;
 		at24_get_pdata(&client->dev, &chip);
-
-		chip.setup = NULL;
-		chip.context = NULL;
 	}
 
 	if (!is_power_of_2(chip.byte_len))
@@ -733,43 +564,10 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		dev_warn(&client->dev,
 			"page_size looks suspicious (no power of 2)!\n");
 
-	/*
-	 * REVISIT: the size of the EUI-48 byte array is 6 in at24mac402, while
-	 * the call to ilog2() in AT24_DEVICE_MAGIC() rounds it down to 4.
-	 *
-	 * Eventually we'll get rid of the magic values altoghether in favor of
-	 * real structs, but for now just manually set the right size.
-	 */
-	if (chip.flags & AT24_FLAG_MAC && chip.byte_len == 4)
-		chip.byte_len = 6;
-
-	/* Use I2C operations unless we're stuck with SMBus extensions. */
-	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
-		if (chip.flags & AT24_FLAG_ADDR16)
-			return -EPFNOSUPPORT;
-
-		if (i2c_check_functionality(client->adapter,
-				I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
-			use_smbus = I2C_SMBUS_I2C_BLOCK_DATA;
-		} else if (i2c_check_functionality(client->adapter,
-				I2C_FUNC_SMBUS_READ_WORD_DATA)) {
-			use_smbus = I2C_SMBUS_WORD_DATA;
-		} else if (i2c_check_functionality(client->adapter,
-				I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
-			use_smbus = I2C_SMBUS_BYTE_DATA;
-		} else {
-			return -EPFNOSUPPORT;
-		}
-
-		if (i2c_check_functionality(client->adapter,
-				I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
-			use_smbus_write = I2C_SMBUS_I2C_BLOCK_DATA;
-		} else if (i2c_check_functionality(client->adapter,
-				I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
-			use_smbus_write = I2C_SMBUS_BYTE_DATA;
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C) &&
+	    !i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_WRITE_I2C_BLOCK))
 		chip.page_size = 1;
-		}
-	}
 
 	if (chip.flags & AT24_FLAG_TAKE8ADDR)
 		num_addresses = 8;
@@ -777,16 +575,28 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		num_addresses =	DIV_ROUND_UP(chip.byte_len,
 			(chip.flags & AT24_FLAG_ADDR16) ? 65536 : 256);
 
+	regmap_config.val_bits = 8;
+	regmap_config.reg_bits = (chip.flags & AT24_FLAG_ADDR16) ? 16 : 8;
+
 	at24 = devm_kzalloc(&client->dev, sizeof(struct at24_data) +
-		num_addresses * sizeof(struct i2c_client *), GFP_KERNEL);
+		num_addresses * sizeof(struct at24_client), GFP_KERNEL);
 	if (!at24)
 		return -ENOMEM;
 
 	mutex_init(&at24->lock);
-	at24->use_smbus = use_smbus;
-	at24->use_smbus_write = use_smbus_write;
 	at24->chip = chip;
 	at24->num_addresses = num_addresses;
+	at24->offset_adj = at24_get_offset_adj(chip.flags, chip.byte_len);
+
+	at24->wp_gpio = devm_gpiod_get_optional(&client->dev,
+						"wp", GPIOD_OUT_HIGH);
+	if (IS_ERR(at24->wp_gpio))
+		return PTR_ERR(at24->wp_gpio);
+
+	at24->client[0].client = client;
+	at24->client[0].regmap = devm_regmap_init_i2c(client, &regmap_config);
+	if (IS_ERR(at24->client[0].regmap))
+		return PTR_ERR(at24->client[0].regmap);
 
 	if ((chip.flags & AT24_FLAG_SERIAL) && (chip.flags & AT24_FLAG_MAC)) {
 		dev_err(&client->dev,
@@ -794,59 +604,32 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		return -EINVAL;
 	}
 
-	if (chip.flags & AT24_FLAG_SERIAL) {
-		at24->read_func = at24_eeprom_read_serial;
-	} else if (chip.flags & AT24_FLAG_MAC) {
-		at24->read_func = at24_eeprom_read_mac;
-	} else {
-		at24->read_func = at24->use_smbus ? at24_eeprom_read_smbus
-						  : at24_eeprom_read_i2c;
-	}
-
-	if (at24->use_smbus) {
-		if (at24->use_smbus_write == I2C_SMBUS_I2C_BLOCK_DATA)
-			at24->write_func = at24_eeprom_write_smbus_block;
-		else
-			at24->write_func = at24_eeprom_write_smbus_byte;
-	} else {
-		at24->write_func = at24_eeprom_write_i2c;
-	}
-
 	writable = !(chip.flags & AT24_FLAG_READONLY);
 	if (writable) {
-		if (!use_smbus || use_smbus_write) {
-
-			unsigned write_max = chip.page_size;
-
-			if (write_max > io_limit)
-				write_max = io_limit;
-			if (use_smbus && write_max > I2C_SMBUS_BLOCK_MAX)
-				write_max = I2C_SMBUS_BLOCK_MAX;
-			at24->write_max = write_max;
-
-			/* buffer (data + address at the beginning) */
-			at24->writebuf = devm_kzalloc(&client->dev,
-				write_max + 2, GFP_KERNEL);
-			if (!at24->writebuf)
-				return -ENOMEM;
-		} else {
-			dev_warn(&client->dev,
-				"cannot write due to controller restrictions.");
+		at24->write_max = min_t(unsigned int,
+					chip.page_size, at24_io_limit);
+		if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C) &&
+		    at24->write_max > I2C_SMBUS_BLOCK_MAX)
+			at24->write_max = I2C_SMBUS_BLOCK_MAX;
 	}
-	}
-
-	at24->client[0] = client;
 
 	/* use dummy devices for multiple-address chips */
 	for (i = 1; i < num_addresses; i++) {
-		at24->client[i] = i2c_new_dummy(client->adapter,
+		at24->client[i].client = i2c_new_dummy(client->adapter,
 						       client->addr + i);
-		if (!at24->client[i]) {
+		if (!at24->client[i].client) {
 			dev_err(&client->dev, "address 0x%02x unavailable\n",
 					client->addr + i);
 			err = -EADDRINUSE;
 			goto err_clients;
 		}
+		at24->client[i].regmap = devm_regmap_init_i2c(
+						at24->client[i].client,
+						&regmap_config);
+		if (IS_ERR(at24->client[i].regmap)) {
+			err = PTR_ERR(at24->client[i].regmap);
+			goto err_clients;
+		}
 	}
 
 	i2c_set_clientdata(client, at24);
@@ -890,12 +673,6 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	dev_info(&client->dev, "%u byte %s EEPROM, %s, %u bytes/write\n",
 		chip.byte_len, client->name,
 		writable ? "writable" : "read-only", at24->write_max);
-	if (use_smbus == I2C_SMBUS_WORD_DATA ||
-	    use_smbus == I2C_SMBUS_BYTE_DATA) {
-		dev_notice(&client->dev, "Falling back to %s reads, "
-			   "performance will suffer\n", use_smbus ==
-			   I2C_SMBUS_WORD_DATA ? "word" : "byte");
-	}
 
 	/* export data to kernel code */
 	if (chip.setup)
@@ -905,8 +682,8 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 
 err_clients:
 	for (i = 1; i < num_addresses; i++)
-		if (at24->client[i])
-			i2c_unregister_device(at24->client[i]);
+		if (at24->client[i].client)
+			i2c_unregister_device(at24->client[i].client);
 
 	pm_runtime_disable(&client->dev);
 
@@ -923,7 +700,7 @@ static int at24_remove(struct i2c_client *client)
 	nvmem_unregister(at24->nvmem);
 
 	for (i = 1; i < at24->num_addresses; i++)
-		i2c_unregister_device(at24->client[i]);
+		i2c_unregister_device(at24->client[i].client);
 
 	pm_runtime_disable(&client->dev);
 	pm_runtime_set_suspended(&client->dev);
@@ -946,12 +723,12 @@ static struct i2c_driver at24_driver = {
 
 static int __init at24_init(void)
 {
-	if (!io_limit) {
-		pr_err("at24: io_limit must not be 0!\n");
+	if (!at24_io_limit) {
+		pr_err("at24: at24_io_limit must not be 0!\n");
 		return -EINVAL;
 	}
 
-	io_limit = rounddown_pow_of_two(io_limit);
+	at24_io_limit = rounddown_pow_of_two(at24_io_limit);
 	return i2c_add_driver(&at24_driver);
 }
 module_init(at24_init);

include/linux/i2c.h

@@ -55,7 +55,7 @@ typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *);
 struct module;
 struct property_entry;
 
-#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
+#if IS_ENABLED(CONFIG_I2C)
 /*
  * The master routines are the ones normally used to transmit data to devices
  * on a bus (or read from them). Apart from two basic transfer functions to
@@ -63,10 +63,68 @@ struct property_entry;
  * transmit an arbitrary number of messages without interruption.
  * @count must be be less than 64k since msg.len is u16.
  */
-extern int i2c_master_send(const struct i2c_client *client, const char *buf,
-			   int count);
-extern int i2c_master_recv(const struct i2c_client *client, char *buf,
-			   int count);
+extern int i2c_transfer_buffer_flags(const struct i2c_client *client,
+				     char *buf, int count, u16 flags);
+
+/**
+ * i2c_master_recv - issue a single I2C message in master receive mode
+ * @client: Handle to slave device
+ * @buf: Where to store data read from slave
+ * @count: How many bytes to read, must be less than 64k since msg.len is u16
+ *
+ * Returns negative errno, or else the number of bytes read.
+ */
+static inline int i2c_master_recv(const struct i2c_client *client,
+				  char *buf, int count)
+{
+	return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);
+};
+
+/**
+ * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
+ *			     using a DMA safe buffer
+ * @client: Handle to slave device
+ * @buf: Where to store data read from slave, must be safe to use with DMA
+ * @count: How many bytes to read, must be less than 64k since msg.len is u16
+ *
+ * Returns negative errno, or else the number of bytes read.
+ */
+static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
+					  char *buf, int count)
+{
+	return i2c_transfer_buffer_flags(client, buf, count,
+					 I2C_M_RD | I2C_M_DMA_SAFE);
+};
+
+/**
+ * i2c_master_send - issue a single I2C message in master transmit mode
+ * @client: Handle to slave device
+ * @buf: Data that will be written to the slave
+ * @count: How many bytes to write, must be less than 64k since msg.len is u16
+ *
+ * Returns negative errno, or else the number of bytes written.
+ */
+static inline int i2c_master_send(const struct i2c_client *client,
+				  const char *buf, int count)
+{
+	return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
+};
+
+/**
+ * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
+ *			     using a DMA safe buffer
+ * @client: Handle to slave device
+ * @buf: Data that will be written to the slave, must be safe to use with DMA
+ * @count: How many bytes to write, must be less than 64k since msg.len is u16
+ *
+ * Returns negative errno, or else the number of bytes written.
+ */
+static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
+					  const char *buf, int count)
+{
+	return i2c_transfer_buffer_flags(client, (char *)buf, count,
+					 I2C_M_DMA_SAFE);
+};
 
 /* Transfer num messages.
  */
@@ -354,7 +412,7 @@ struct i2c_board_info {
 	.type = dev_type, .addr = (dev_addr)
 
 
-#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
+#if IS_ENABLED(CONFIG_I2C)
 /* Add-on boards should register/unregister their devices; e.g. a board
  * with integrated I2C, a config eeprom, sensors, and a codec that's
  * used in conjunction with the primary hardware.
@@ -485,40 +543,43 @@ struct i2c_timings {
 /**
  * struct i2c_bus_recovery_info - I2C bus recovery information
  * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
- *	i2c_generic_scl_recovery() or i2c_generic_gpio_recovery().
+ *	i2c_generic_scl_recovery().
  * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
- *      recovery. Used internally for generic GPIO recovery.
- * @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used
- *      internally for generic GPIO recovery.
+ *      recovery. Populated internally for generic GPIO recovery.
+ * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
+ *      Populated internally for generic GPIO recovery.
  * @get_sda: This gets current value of SDA line. Optional for generic SCL
- *      recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO
+ *      recovery. Populated internally, if sda_gpio is a valid GPIO, for generic
+ *      GPIO recovery.
+ * @set_sda: This sets/clears the SDA line. Optional for generic SCL recovery.
+ *	Populated internally, if sda_gpio is a valid GPIO, for generic GPIO
  *	recovery.
  * @prepare_recovery: This will be called before starting recovery. Platform may
  *	configure padmux here for SDA/SCL line or something else they want.
  * @unprepare_recovery: This will be called after completing recovery. Platform
  *	may configure padmux here for SDA/SCL line or something else they want.
- * @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery.
- * @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery.
+ * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
+ * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
  */
 struct i2c_bus_recovery_info {
-	int (*recover_bus)(struct i2c_adapter *);
+	int (*recover_bus)(struct i2c_adapter *adap);
 
-	int (*get_scl)(struct i2c_adapter *);
-	void (*set_scl)(struct i2c_adapter *, int val);
-	int (*get_sda)(struct i2c_adapter *);
+	int (*get_scl)(struct i2c_adapter *adap);
+	void (*set_scl)(struct i2c_adapter *adap, int val);
+	int (*get_sda)(struct i2c_adapter *adap);
+	void (*set_sda)(struct i2c_adapter *adap, int val);
 
-	void (*prepare_recovery)(struct i2c_adapter *);
-	void (*unprepare_recovery)(struct i2c_adapter *);
+	void (*prepare_recovery)(struct i2c_adapter *adap);
+	void (*unprepare_recovery)(struct i2c_adapter *adap);
 
 	/* gpio recovery */
-	int scl_gpio;
-	int sda_gpio;
+	struct gpio_desc *scl_gpiod;
+	struct gpio_desc *sda_gpiod;
 };
 
 int i2c_recover_bus(struct i2c_adapter *adap);
 
 /* Generic recovery routines */
-int i2c_generic_gpio_recovery(struct i2c_adapter *adap);
 int i2c_generic_scl_recovery(struct i2c_adapter *adap);
 
 /**
@@ -706,7 +767,7 @@ i2c_unlock_adapter(struct i2c_adapter *adapter)
 
 /* administration...
  */
-#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
+#if IS_ENABLED(CONFIG_I2C)
 extern int i2c_add_adapter(struct i2c_adapter *);
 extern void i2c_del_adapter(struct i2c_adapter *);
 extern int i2c_add_numbered_adapter(struct i2c_adapter *);
@@ -769,6 +830,9 @@ static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
 	return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
 }
 
+u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
+void i2c_release_dma_safe_msg_buf(struct i2c_msg *msg, u8 *buf);
+
 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
 /**
  * module_i2c_driver() - Helper macro for registering a modular I2C driver

include/linux/platform_data/at24.h

@@ -50,6 +50,8 @@ struct at24_platform_data {
 #define AT24_FLAG_TAKE8ADDR	BIT(4)	/* take always 8 addresses (24c00) */
 #define AT24_FLAG_SERIAL	BIT(3)	/* factory-programmed serial number */
 #define AT24_FLAG_MAC		BIT(2)	/* factory-programmed mac address */
+#define AT24_FLAG_NO_RDROL	BIT(1)	/* does not auto-rollover reads to */
+					/* the next slave address */
 
 	void		(*setup)(struct nvmem_device *nvmem, void *context);
 	void		*context;

include/linux/platform_data/i2c-davinci.h

@@ -16,9 +16,8 @@
 struct davinci_i2c_platform_data {
 	unsigned int	bus_freq;	/* standard bus frequency (kHz) */
 	unsigned int	bus_delay;	/* post-transaction delay (usec) */
-	unsigned int    sda_pin;        /* GPIO pin ID to use for SDA */
-	unsigned int    scl_pin;        /* GPIO pin ID to use for SCL */
-	bool		has_pfunc;	/*chip has a ICPFUNC register */
+	bool		gpio_recovery;	/* Use GPIO recovery method */
+	bool		has_pfunc;	/* Chip has a ICPFUNC register */
 };
 
 /* for board setup code */

include/uapi/linux/i2c.h

@@ -72,6 +72,9 @@ struct i2c_msg {
 #define I2C_M_RD		0x0001	/* read data, from slave to master */
 					/* I2C_M_RD is guaranteed to be 0x0001! */
 #define I2C_M_TEN		0x0010	/* this is a ten bit chip address */
+#define I2C_M_DMA_SAFE		0x0200	/* the buffer of this message is DMA safe */
+					/* makes only sense in kernelspace */
+					/* userspace buffers are copied anyway */
 #define I2C_M_RECV_LEN		0x0400	/* length will be first received byte */
 #define I2C_M_NO_RD_ACK		0x0800	/* if I2C_FUNC_PROTOCOL_MANGLING */
 #define I2C_M_IGNORE_NAK	0x1000	/* if I2C_FUNC_PROTOCOL_MANGLING */