Merge branch 'i2c/for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "Highlights:

   - new drivers for Mediatek I2C, APM X-Gene, Broadcom Settop
   - major updates to at91, davinci
   - bugfixes to the mux infrastructure when dealing with the new quirk
     mechanism
   - more users for the bus recovery feature
   - further improvements to the slave framework

  Plus the usual bunch of smaller driver and core improvements and
  fixes.

  There is one patch removing old code from an ARM platform.  This has
  been acked by the sh_mobile maintainer Simon Horman"

* 'i2c/for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (48 commits)
  i2c: busses: i2c-bcm2835: limits cdiv to allowed values
  i2c: sh_mobile: use proper type for timeout
  i2c: sh_mobile: use adapter default for timeout
  i2c: rcar: use proper type for timeout
  i2c: rcar: use adapter default for timeout
  i2c: designware: Make sure the device is suspended before disabling runtime PM
  i2c: tegra: apply size limit quirk
  i2c: tegra: don't advertise SMBUS_QUICK
  i2c: octeon: remove unused signal handling
  i2c: davinci: Optimize SCL generation
  i2c: mux: pca954x: Use __i2c_transfer because of quirks
  i2c: mux: Use __i2c_transfer() instead of calling parent's master_xfer()
  i2c: use parent adapter quirks in mux
  i2c: bcm2835: clear reserved bits in S-Register
  ARM: shmobile: r8a7740: remove I2C errata handling
  i2c: sh_mobile: add errata workaround
  i2c: at91: fix code checker warnings
  i2c: busses: xgene-slimpro: fix incorrect __init declation for probe
  i2c: davinci: Avoid sending to own address
  i2c: davinci: Refactor i2c_davinci_wait_bus_not_busy()
  ...

Documentation/devicetree/bindings/i2c/i2c-at91.txt

@@ -2,8 +2,8 @@ I2C for Atmel platforms
 
 Required properties :
 - compatible : Must be "atmel,at91rm9200-i2c", "atmel,at91sam9261-i2c",
-     "atmel,at91sam9260-i2c", "atmel,at91sam9g20-i2c", "atmel,at91sam9g10-i2c"
-     or "atmel,at91sam9x5-i2c"
+     "atmel,at91sam9260-i2c", "atmel,at91sam9g20-i2c", "atmel,at91sam9g10-i2c",
+     "atmel,at91sam9x5-i2c" or "atmel,sama5d2-i2c"
 - reg: physical base address of the controller and length of memory mapped
      region.
 - interrupts: interrupt number to the cpu.
@@ -13,6 +13,10 @@ Required properties :
 
 Optional properties:
 - clock-frequency: Desired I2C bus frequency in Hz, otherwise defaults to 100000
+- dmas: A list of two dma specifiers, one for each entry in dma-names.
+- dma-names: should contain "tx" and "rx".
+- atmel,fifo-size: maximum number of data the RX and TX FIFOs can store for FIFO
+  capable I2C controllers.
 - Child nodes conforming to i2c bus binding
 
 Examples :
@@ -32,3 +36,25 @@ i2c0: i2c@fff84000 {
 		pagesize = <128>;
 	}
 }
+
+i2c0: i2c@f8034600 {
+	compatible = "atmel,sama5d2-i2c";
+	reg = <0xf8034600 0x100>;
+	interrupts = <19 IRQ_TYPE_LEVEL_HIGH 7>;
+	dmas = <&dma0
+		(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1))
+		AT91_XDMAC_DT_PERID(11)>,
+	       <&dma0
+		(AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1))
+		AT91_XDMAC_DT_PERID(12)>;
+	dma-names = "tx", "rx";
+	#address-cells = <1>;
+	#size-cells = <0>;
+	clocks = <&flx0>;
+	atmel,fifo-size = <16>;
+
+	wm8731: wm8731@1a {
+		compatible = "wm8731";
+		reg = <0x1a>;
+	};
+};

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

+Broadcom stb bsc iic master controller
+
+Required properties:
+
+- compatible: should be "brcm,brcmstb-i2c"
+- clock-frequency: 32-bit decimal value of iic master clock freqency in Hz
+		   valid values are 375000, 390000, 187500, 200000
+		   93750, 97500, 46875 and 50000
+- reg: specifies the base physical address and size of the registers
+
+Optional properties :
+
+- interrupt-parent: specifies the phandle to the parent interrupt controller
+  this one is cascaded from
+- interrupts: specifies the interrupt number, the irq line to be used
+- interrupt-names: Interrupt name string
+
+Example:
+
+bsca: i2c@f0406200 {
+      clock-frequency = <390000>;
+      compatible = "brcm,brcmstb-i2c";
+      interrupt-parent = <&irq0_intc>;
+      reg = <0xf0406200 0x58>;
+      interrupts = <0x18>;
+      interrupt-names = "upg_bsca";
+};
+

Documentation/devicetree/bindings/i2c/i2c-mt6577.txt

+* Mediatek's I2C controller
+
+The Mediatek's I2C controller is used to interface with I2C devices.
+
+Required properties:
+  - compatible: value should be either of the following.
+      (a) "mediatek,mt6577-i2c", for i2c compatible with mt6577 i2c.
+      (b) "mediatek,mt6589-i2c", for i2c compatible with mt6589 i2c.
+      (c) "mediatek,mt8127-i2c", for i2c compatible with mt8127 i2c.
+      (d) "mediatek,mt8135-i2c", for i2c compatible with mt8135 i2c.
+      (e) "mediatek,mt8173-i2c", for i2c compatible with mt8173 i2c.
+  - reg: physical base address of the controller and dma base, length of memory
+    mapped region.
+  - interrupts: interrupt number to the cpu.
+  - clock-div: the fixed value for frequency divider of clock source in i2c
+    module. Each IC may be different.
+  - clocks: clock name from clock manager
+  - clock-names: Must include "main" and "dma", if enable have-pmic need include
+    "pmic" extra.
+
+Optional properties:
+  - clock-frequency: Frequency in Hz of the bus when transfer, the default value
+    is 100000.
+  - mediatek,have-pmic: platform can control i2c form special pmic side.
+    Only mt6589 and mt8135 support this feature.
+  - mediatek,use-push-pull: IO config use push-pull mode.
+
+Example:
+
+	i2c0: i2c@1100d000 {
+			compatible = "mediatek,mt6577-i2c";
+			reg = <0x1100d000 0x70>,
+			      <0x11000300 0x80>;
+			interrupts = <GIC_SPI 44 IRQ_TYPE_LEVEL_LOW>;
+			clock-frequency = <400000>;
+			mediatek,have-pmic;
+			clock-div = <16>;
+			clocks = <&i2c0_ck>, <&ap_dma_ck>;
+			clock-names = "main", "dma";
+	};
+

Documentation/devicetree/bindings/i2c/i2c-xgene-slimpro.txt

+APM X-Gene SLIMpro Mailbox I2C Driver
+
+An I2C controller accessed over the "SLIMpro" mailbox.
+
+Required properties :
+
+ - compatible : should be "apm,xgene-slimpro-i2c"
+ - mboxes : use the label reference for the mailbox as the first parameter.
+	    The second parameter is the channel number.
+
+Example :
+	i2cslimpro {
+		compatible = "apm,xgene-slimpro-i2c";
+		mboxes = <&mailbox 0>;
+	};

Documentation/i2c/slave-interface

@@ -3,16 +3,16 @@ Linux I2C slave interface description
 
 by Wolfram Sang <wsa@sang-engineering.com> in 2014-15
 
-Linux can also be an I2C slave in case I2C controllers have slave support.
-Besides this HW requirement, one also needs a software backend providing the
-actual functionality. An example for this is the slave-eeprom driver, which
-acts as a dual memory driver. While another I2C master on the bus can access it
-like a regular EEPROM, the Linux I2C slave can access the content via sysfs and
-retrieve/provide information as needed. The software backend driver and the I2C
-bus driver communicate via events. Here is a small graph visualizing the data
-flow and the means by which data is transported. The dotted line marks only one
-example. The backend could also use e.g. a character device, be in-kernel
-only, or something completely different:
+Linux can also be an I2C slave if the I2C controller in use has slave
+functionality. For that to work, one needs slave support in the bus driver plus
+a hardware independent software backend providing the actual functionality. An
+example for the latter is the slave-eeprom driver, which acts as a dual memory
+driver. While another I2C master on the bus can access it like a regular
+EEPROM, the Linux I2C slave can access the content via sysfs and handle data as
+needed. The backend driver and the I2C bus driver communicate via events. Here
+is a small graph visualizing the data flow and the means by which data is
+transported. The dotted line marks only one example. The backend could also
+use a character device, be in-kernel only, or something completely different:
 
 
               e.g. sysfs        I2C slave events        I/O registers
@@ -43,6 +43,11 @@ behaviour and setup.
 Developer manual
 ================
 
+First, the events which are used by the bus driver and the backend will be
+described in detail. After that, some implementation hints for extending bus
+drivers and writing backends will be given.
+
+
 I2C slave events
 ----------------
 

arch/arm/mach-shmobile/setup-r8a7740.c

@@ -13,7 +13,6 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */
-#include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
@@ -690,56 +689,6 @@ void __init r8a7740_meram_workaround(void)
 	}
 }
 
-#define ICCR	0x0004
-#define ICSTART	0x0070
-
-#define i2c_read(reg, offset)		ioread8(reg + offset)
-#define i2c_write(reg, offset, data)	iowrite8(data, reg + offset)
-
-/*
- * r8a7740 chip has lasting errata on I2C I/O pad reset.
- * this is work-around for it.
- */
-static void r8a7740_i2c_workaround(struct platform_device *pdev)
-{
-	struct resource *res;
-	void __iomem *reg;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (unlikely(!res)) {
-		pr_err("r8a7740 i2c workaround fail (cannot find resource)\n");
-		return;
-	}
-
-	reg = ioremap(res->start, resource_size(res));
-	if (unlikely(!reg)) {
-		pr_err("r8a7740 i2c workaround fail (cannot map IO)\n");
-		return;
-	}
-
-	i2c_write(reg, ICCR, i2c_read(reg, ICCR) | 0x80);
-	i2c_read(reg, ICCR); /* dummy read */
-
-	i2c_write(reg, ICSTART, i2c_read(reg, ICSTART) | 0x10);
-	i2c_read(reg, ICSTART); /* dummy read */
-
-	udelay(10);
-
-	i2c_write(reg, ICCR, 0x01);
-	i2c_write(reg, ICSTART, 0x00);
-
-	udelay(10);
-
-	i2c_write(reg, ICCR, 0x10);
-	udelay(10);
-	i2c_write(reg, ICCR, 0x00);
-	udelay(10);
-	i2c_write(reg, ICCR, 0x10);
-	udelay(10);
-
-	iounmap(reg);
-}
-
 void __init r8a7740_add_standard_devices(void)
 {
 	static struct pm_domain_device domain_devices[] __initdata = {
@@ -766,10 +715,6 @@ void __init r8a7740_add_standard_devices(void)
 		{ "A3SP", &usb_dma_device },
 	};
 
-	/* I2C work-around */
-	r8a7740_i2c_workaround(&i2c0_device);
-	r8a7740_i2c_workaround(&i2c1_device);
-
 	r8a7740_init_pm_domains();
 
 	/* add devices */

drivers/i2c/algos/i2c-algo-pca.c

@@ -521,7 +521,7 @@ static int pca_init(struct i2c_adapter *adap)
 
 		pca_set_con(pca_data, I2C_PCA_CON_ENSIO);
 	}
-	udelay(500); /* 500 us for oscilator to stabilise */
+	udelay(500); /* 500 us for oscillator to stabilise */
 
 	return 0;
 }

drivers/i2c/busses/Kconfig

@@ -392,6 +392,16 @@ config I2C_BCM_KONA
 
 	  If you do not need KONA I2C interface, say N.
 
+config I2C_BRCMSTB
+	tristate "BRCM Settop I2C controller"
+	depends on ARCH_BRCMSTB || COMPILE_TEST
+	default y
+	help
+	  If you say yes to this option, support will be included for the
+	  I2C interface on the Broadcom Settop SoCs.
+
+	  If you do not need I2C interface, say N.
+
 config I2C_BLACKFIN_TWI
 	tristate "Blackfin TWI I2C support"
 	depends on BLACKFIN
@@ -419,7 +429,7 @@ config I2C_CADENCE
 
 config I2C_CBUS_GPIO
 	tristate "CBUS I2C driver"
-	depends on GPIOLIB
+	depends on GPIOLIB || COMPILE_TEST
 	help
 	  Support for CBUS access using I2C API. Mostly relevant for Nokia
 	  Internet Tablets (770, N800 and N810).
@@ -525,7 +535,7 @@ config I2C_EXYNOS5
 
 config I2C_GPIO
 	tristate "GPIO-based bitbanging I2C"
-	depends on GPIOLIB
+	depends on GPIOLIB || COMPILE_TEST
 	select I2C_ALGOBIT
 	help
 	  This is a very simple bitbanging I2C driver utilizing the
@@ -620,6 +630,15 @@ config I2C_MPC
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-mpc.
 
+config I2C_MT65XX
+	tristate "MediaTek I2C adapter"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	help
+	  This selects the MediaTek(R) Integrated Inter Circuit bus driver
+	  for MT65xx and MT81xx.
+	  If you want to use MediaTek(R) I2C interface, say Y or M here.
+	  If unsure, say N.
+
 config I2C_MV64XXX
 	tristate "Marvell mv64xxx I2C Controller"
 	depends on MV64X60 || PLAT_ORION || ARCH_SUNXI
@@ -1110,6 +1129,15 @@ config I2C_CROS_EC_TUNNEL
 	  connected there. This will work whatever the interface used to
 	  talk to the EC (SPI, I2C or LPC).
 
+config I2C_XGENE_SLIMPRO
+	tristate "APM X-Gene SoC I2C SLIMpro devices support"
+	depends on ARCH_XGENE && MAILBOX
+	help
+	  Enable I2C bus access using the APM X-Gene SoC SLIMpro
+	  co-processor. The I2C device access the I2C bus via the X-Gene
+	  to SLIMpro (On chip coprocessor) mailbox mechanism.
+	  If unsure, say N.
+
 config SCx200_ACB
 	tristate "Geode ACCESS.bus support"
 	depends on X86_32 && PCI

drivers/i2c/busses/Makefile

@@ -60,6 +60,7 @@ obj-$(CONFIG_I2C_JZ4780)	+= i2c-jz4780.o
 obj-$(CONFIG_I2C_KEMPLD)	+= i2c-kempld.o
 obj-$(CONFIG_I2C_MESON)		+= i2c-meson.o
 obj-$(CONFIG_I2C_MPC)		+= i2c-mpc.o
+obj-$(CONFIG_I2C_MT65XX)	+= i2c-mt65xx.o
 obj-$(CONFIG_I2C_MV64XXX)	+= i2c-mv64xxx.o
 obj-$(CONFIG_I2C_MXS)		+= i2c-mxs.o
 obj-$(CONFIG_I2C_NOMADIK)	+= i2c-nomadik.o
@@ -105,11 +106,13 @@ obj-$(CONFIG_I2C_VIPERBOARD)	+= i2c-viperboard.o
 # Other I2C/SMBus bus drivers
 obj-$(CONFIG_I2C_ACORN)		+= i2c-acorn.o
 obj-$(CONFIG_I2C_BCM_KONA)	+= i2c-bcm-kona.o
+obj-$(CONFIG_I2C_BRCMSTB)	+= i2c-brcmstb.o
 obj-$(CONFIG_I2C_CROS_EC_TUNNEL)	+= i2c-cros-ec-tunnel.o
 obj-$(CONFIG_I2C_ELEKTOR)	+= i2c-elektor.o
 obj-$(CONFIG_I2C_OPAL)		+= i2c-opal.o
 obj-$(CONFIG_I2C_PCA_ISA)	+= i2c-pca-isa.o
 obj-$(CONFIG_I2C_SIBYTE)	+= i2c-sibyte.o
+obj-$(CONFIG_I2C_XGENE_SLIMPRO) += i2c-xgene-slimpro.o
 obj-$(CONFIG_SCx200_ACB)	+= scx200_acb.o
 
 ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG

drivers/i2c/busses/i2c-at91.c

@@ -41,29 +41,41 @@
 
 /* AT91 TWI register definitions */
 #define	AT91_TWI_CR		0x0000	/* Control Register */
-#define	AT91_TWI_START		0x0001	/* Send a Start Condition */
-#define	AT91_TWI_STOP		0x0002	/* Send a Stop Condition */
-#define	AT91_TWI_MSEN		0x0004	/* Master Transfer Enable */
-#define	AT91_TWI_SVDIS		0x0020	/* Slave Transfer Disable */
-#define	AT91_TWI_QUICK		0x0040	/* SMBus quick command */
-#define	AT91_TWI_SWRST		0x0080	/* Software Reset */
+#define	AT91_TWI_START		BIT(0)	/* Send a Start Condition */
+#define	AT91_TWI_STOP		BIT(1)	/* Send a Stop Condition */
+#define	AT91_TWI_MSEN		BIT(2)	/* Master Transfer Enable */
+#define	AT91_TWI_MSDIS		BIT(3)	/* Master Transfer Disable */
+#define	AT91_TWI_SVEN		BIT(4)	/* Slave Transfer Enable */
+#define	AT91_TWI_SVDIS		BIT(5)	/* Slave Transfer Disable */
+#define	AT91_TWI_QUICK		BIT(6)	/* SMBus quick command */
+#define	AT91_TWI_SWRST		BIT(7)	/* Software Reset */
+#define	AT91_TWI_ACMEN		BIT(16) /* Alternative Command Mode Enable */
+#define	AT91_TWI_ACMDIS		BIT(17) /* Alternative Command Mode Disable */
+#define	AT91_TWI_THRCLR		BIT(24) /* Transmit Holding Register Clear */
+#define	AT91_TWI_RHRCLR		BIT(25) /* Receive Holding Register Clear */
+#define	AT91_TWI_LOCKCLR	BIT(26) /* Lock Clear */
+#define	AT91_TWI_FIFOEN		BIT(28) /* FIFO Enable */
+#define	AT91_TWI_FIFODIS	BIT(29) /* FIFO Disable */
 
 #define	AT91_TWI_MMR		0x0004	/* Master Mode Register */
 #define	AT91_TWI_IADRSZ_1	0x0100	/* Internal Device Address Size */
-#define	AT91_TWI_MREAD		0x1000	/* Master Read Direction */
+#define	AT91_TWI_MREAD		BIT(12)	/* Master Read Direction */
 
 #define	AT91_TWI_IADR		0x000c	/* Internal Address Register */
 
 #define	AT91_TWI_CWGR		0x0010	/* Clock Waveform Generator Reg */
 
 #define	AT91_TWI_SR		0x0020	/* Status Register */
-#define	AT91_TWI_TXCOMP		0x0001	/* Transmission Complete */
-#define	AT91_TWI_RXRDY		0x0002	/* Receive Holding Register Ready */
-#define	AT91_TWI_TXRDY		0x0004	/* Transmit Holding Register Ready */
+#define	AT91_TWI_TXCOMP		BIT(0)	/* Transmission Complete */
+#define	AT91_TWI_RXRDY		BIT(1)	/* Receive Holding Register Ready */
+#define	AT91_TWI_TXRDY		BIT(2)	/* Transmit Holding Register Ready */
+#define	AT91_TWI_OVRE		BIT(6)	/* Overrun Error */
+#define	AT91_TWI_UNRE		BIT(7)	/* Underrun Error */
+#define	AT91_TWI_NACK		BIT(8)	/* Not Acknowledged */
+#define	AT91_TWI_LOCK		BIT(23) /* TWI Lock due to Frame Errors */
 
-#define	AT91_TWI_OVRE		0x0040	/* Overrun Error */
-#define	AT91_TWI_UNRE		0x0080	/* Underrun Error */
-#define	AT91_TWI_NACK		0x0100	/* Not Acknowledged */
+#define	AT91_TWI_INT_MASK \
+	(AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY | AT91_TWI_NACK)
 
 #define	AT91_TWI_IER		0x0024	/* Interrupt Enable Register */
 #define	AT91_TWI_IDR		0x0028	/* Interrupt Disable Register */
@@ -71,17 +83,40 @@
 #define	AT91_TWI_RHR		0x0030	/* Receive Holding Register */
 #define	AT91_TWI_THR		0x0034	/* Transmit Holding Register */
 
+#define	AT91_TWI_ACR		0x0040	/* Alternative Command Register */
+#define	AT91_TWI_ACR_DATAL(len)	((len) & 0xff)
+#define	AT91_TWI_ACR_DIR	BIT(8)
+
+#define	AT91_TWI_FMR		0x0050	/* FIFO Mode Register */
+#define	AT91_TWI_FMR_TXRDYM(mode)	(((mode) & 0x3) << 0)
+#define	AT91_TWI_FMR_TXRDYM_MASK	(0x3 << 0)
+#define	AT91_TWI_FMR_RXRDYM(mode)	(((mode) & 0x3) << 4)
+#define	AT91_TWI_FMR_RXRDYM_MASK	(0x3 << 4)
+#define	AT91_TWI_ONE_DATA	0x0
+#define	AT91_TWI_TWO_DATA	0x1
+#define	AT91_TWI_FOUR_DATA	0x2
+
+#define	AT91_TWI_FLR		0x0054	/* FIFO Level Register */
+
+#define	AT91_TWI_FSR		0x0060	/* FIFO Status Register */
+#define	AT91_TWI_FIER		0x0064	/* FIFO Interrupt Enable Register */
+#define	AT91_TWI_FIDR		0x0068	/* FIFO Interrupt Disable Register */
+#define	AT91_TWI_FIMR		0x006c	/* FIFO Interrupt Mask Register */
+
+#define	AT91_TWI_VER		0x00fc	/* Version Register */
+
 struct at91_twi_pdata {
 	unsigned clk_max_div;
 	unsigned clk_offset;
 	bool has_unre_flag;
+	bool has_alt_cmd;
 	struct at_dma_slave dma_slave;
 };
 
 struct at91_twi_dma {
 	struct dma_chan *chan_rx;
 	struct dma_chan *chan_tx;
-	struct scatterlist sg;
+	struct scatterlist sg[2];
 	struct dma_async_tx_descriptor *data_desc;
 	enum dma_data_direction direction;
 	bool buf_mapped;
@@ -104,6 +139,7 @@ struct at91_twi_dev {
 	struct at91_twi_pdata *pdata;
 	bool use_dma;
 	bool recv_len_abort;
+	u32 fifo_size;
 	struct at91_twi_dma dma;
 };
 
@@ -119,13 +155,12 @@ static void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)
 
 static void at91_disable_twi_interrupts(struct at91_twi_dev *dev)
 {
-	at91_twi_write(dev, AT91_TWI_IDR,
-		       AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY);
+	at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);
 }
 
 static void at91_twi_irq_save(struct at91_twi_dev *dev)
 {
-	dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & 0x7;
+	dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK;
 	at91_disable_twi_interrupts(dev);
 }
 
@@ -138,6 +173,9 @@ static void at91_init_twi_bus(struct at91_twi_dev *dev)
 {
 	at91_disable_twi_interrupts(dev);
 	at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST);
+	/* FIFO should be enabled immediately after the software reset */
+	if (dev->fifo_size)
+		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_FIFOEN);
 	at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_MSEN);
 	at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SVDIS);
 	at91_twi_write(dev, AT91_TWI_CWGR, dev->twi_cwgr_reg);
@@ -184,7 +222,7 @@ static void at91_twi_dma_cleanup(struct at91_twi_dev *dev)
 		dma->xfer_in_progress = false;
 	}
 	if (dma->buf_mapped) {
-		dma_unmap_single(dev->dev, sg_dma_address(&dma->sg),
+		dma_unmap_single(dev->dev, sg_dma_address(&dma->sg[0]),
 				 dev->buf_len, dma->direction);
 		dma->buf_mapped = false;
 	}
@@ -194,14 +232,16 @@ static void at91_twi_dma_cleanup(struct at91_twi_dev *dev)
 
 static void at91_twi_write_next_byte(struct at91_twi_dev *dev)
 {
-	if (dev->buf_len <= 0)
+	if (!dev->buf_len)
 		return;
 
-	at91_twi_write(dev, AT91_TWI_THR, *dev->buf);
+	/* 8bit write works with and without FIFO */
+	writeb_relaxed(*dev->buf, dev->base + AT91_TWI_THR);
 
 	/* send stop when last byte has been written */
 	if (--dev->buf_len == 0)
-		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);
+		if (!dev->pdata->has_alt_cmd)
+			at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);
 
 	dev_dbg(dev->dev, "wrote 0x%x, to go %d\n", *dev->buf, dev->buf_len);
 
@@ -212,10 +252,19 @@ static void at91_twi_write_data_dma_callback(void *data)
 {
 	struct at91_twi_dev *dev = (struct at91_twi_dev *)data;
 
-	dma_unmap_single(dev->dev, sg_dma_address(&dev->dma.sg),
+	dma_unmap_single(dev->dev, sg_dma_address(&dev->dma.sg[0]),
 			 dev->buf_len, DMA_TO_DEVICE);
 
-	at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);
+	/*
+	 * When this callback is called, THR/TX FIFO is likely not to be empty
+	 * yet. So we have to wait for TXCOMP or NACK bits to be set into the
+	 * Status Register to be sure that the STOP bit has been sent and the
+	 * transfer is completed. The NACK interrupt has already been enabled,
+	 * we just have to enable TXCOMP one.
+	 */
+	at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_TXCOMP);
+	if (!dev->pdata->has_alt_cmd)
+		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);
 }
 
 static void at91_twi_write_data_dma(struct at91_twi_dev *dev)
@@ -224,8 +273,9 @@ static void at91_twi_write_data_dma(struct at91_twi_dev *dev)
 	struct dma_async_tx_descriptor *txdesc;
 	struct at91_twi_dma *dma = &dev->dma;
 	struct dma_chan *chan_tx = dma->chan_tx;
+	unsigned int sg_len = 1;
 
-	if (dev->buf_len <= 0)
+	if (!dev->buf_len)
 		return;
 
 	dma->direction = DMA_TO_DEVICE;
@@ -239,10 +289,43 @@ static void at91_twi_write_data_dma(struct at91_twi_dev *dev)
 	}
 	dma->buf_mapped = true;
 	at91_twi_irq_restore(dev);
-	sg_dma_len(&dma->sg) = dev->buf_len;
-	sg_dma_address(&dma->sg) = dma_addr;
 
-	txdesc = dmaengine_prep_slave_sg(chan_tx, &dma->sg, 1, DMA_MEM_TO_DEV,
+	if (dev->fifo_size) {
+		size_t part1_len, part2_len;
+		struct scatterlist *sg;
+		unsigned fifo_mr;
+
+		sg_len = 0;
+
+		part1_len = dev->buf_len & ~0x3;
+		if (part1_len) {
+			sg = &dma->sg[sg_len++];
+			sg_dma_len(sg) = part1_len;
+			sg_dma_address(sg) = dma_addr;
+		}
+
+		part2_len = dev->buf_len & 0x3;
+		if (part2_len) {
+			sg = &dma->sg[sg_len++];
+			sg_dma_len(sg) = part2_len;
+			sg_dma_address(sg) = dma_addr + part1_len;
+		}
+
+		/*
+		 * DMA controller is triggered when at least 4 data can be
+		 * written into the TX FIFO
+		 */
+		fifo_mr = at91_twi_read(dev, AT91_TWI_FMR);
+		fifo_mr &= ~AT91_TWI_FMR_TXRDYM_MASK;
+		fifo_mr |= AT91_TWI_FMR_TXRDYM(AT91_TWI_FOUR_DATA);
+		at91_twi_write(dev, AT91_TWI_FMR, fifo_mr);
+	} else {
+		sg_dma_len(&dma->sg[0]) = dev->buf_len;
+		sg_dma_address(&dma->sg[0]) = dma_addr;
+	}
+
+	txdesc = dmaengine_prep_slave_sg(chan_tx, dma->sg, sg_len,
+					 DMA_MEM_TO_DEV,
 					 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!txdesc) {
 		dev_err(dev->dev, "dma prep slave sg failed\n");
@@ -264,10 +347,11 @@ static void at91_twi_write_data_dma(struct at91_twi_dev *dev)
 
 static void at91_twi_read_next_byte(struct at91_twi_dev *dev)
 {
-	if (dev->buf_len <= 0)
+	if (!dev->buf_len)
 		return;
 
-	*dev->buf = at91_twi_read(dev, AT91_TWI_RHR) & 0xff;
+	/* 8bit read works with and without FIFO */
+	*dev->buf = readb_relaxed(dev->base + AT91_TWI_RHR);
 	--dev->buf_len;
 
 	/* return if aborting, we only needed to read RHR to clear RXRDY*/
@@ -291,7 +375,7 @@ static void at91_twi_read_next_byte(struct at91_twi_dev *dev)
 	}
 
 	/* send stop if second but last byte has been read */
-	if (dev->buf_len == 1)
+	if (!dev->pdata->has_alt_cmd && dev->buf_len == 1)
 		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);
 
 	dev_dbg(dev->dev, "read 0x%x, to go %d\n", *dev->buf, dev->buf_len);
@@ -302,14 +386,18 @@ static void at91_twi_read_next_byte(struct at91_twi_dev *dev)
 static void at91_twi_read_data_dma_callback(void *data)
 {
 	struct at91_twi_dev *dev = (struct at91_twi_dev *)data;
+	unsigned ier = AT91_TWI_TXCOMP;
 
-	dma_unmap_single(dev->dev, sg_dma_address(&dev->dma.sg),
+	dma_unmap_single(dev->dev, sg_dma_address(&dev->dma.sg[0]),
 			 dev->buf_len, DMA_FROM_DEVICE);
 
-	/* The last two bytes have to be read without using dma */
-	dev->buf += dev->buf_len - 2;
-	dev->buf_len = 2;
-	at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_RXRDY);
+	if (!dev->pdata->has_alt_cmd) {
+		/* The last two bytes have to be read without using dma */
+		dev->buf += dev->buf_len - 2;
+		dev->buf_len = 2;
+		ier |= AT91_TWI_RXRDY;
+	}
+	at91_twi_write(dev, AT91_TWI_IER, ier);
 }
 
 static void at91_twi_read_data_dma(struct at91_twi_dev *dev)
@@ -318,23 +406,38 @@ static void at91_twi_read_data_dma(struct at91_twi_dev *dev)
 	struct dma_async_tx_descriptor *rxdesc;
 	struct at91_twi_dma *dma = &dev->dma;
 	struct dma_chan *chan_rx = dma->chan_rx;
+	size_t buf_len;
 
+	buf_len = (dev->pdata->has_alt_cmd) ? dev->buf_len : dev->buf_len - 2;
 	dma->direction = DMA_FROM_DEVICE;
 
 	/* Keep in mind that we won't use dma to read the last two bytes */
 	at91_twi_irq_save(dev);
-	dma_addr = dma_map_single(dev->dev, dev->buf, dev->buf_len - 2,
-				  DMA_FROM_DEVICE);
+	dma_addr = dma_map_single(dev->dev, dev->buf, buf_len, DMA_FROM_DEVICE);
 	if (dma_mapping_error(dev->dev, dma_addr)) {
 		dev_err(dev->dev, "dma map failed\n");
 		return;
 	}
 	dma->buf_mapped = true;
 	at91_twi_irq_restore(dev);
-	dma->sg.dma_address = dma_addr;
-	sg_dma_len(&dma->sg) = dev->buf_len - 2;
 
-	rxdesc = dmaengine_prep_slave_sg(chan_rx, &dma->sg, 1, DMA_DEV_TO_MEM,
+	if (dev->fifo_size && IS_ALIGNED(buf_len, 4)) {
+		unsigned fifo_mr;
+
+		/*
+		 * DMA controller is triggered when at least 4 data can be
+		 * read from the RX FIFO
+		 */
+		fifo_mr = at91_twi_read(dev, AT91_TWI_FMR);
+		fifo_mr &= ~AT91_TWI_FMR_RXRDYM_MASK;
+		fifo_mr |= AT91_TWI_FMR_RXRDYM(AT91_TWI_FOUR_DATA);
+		at91_twi_write(dev, AT91_TWI_FMR, fifo_mr);
+	}
+
+	sg_dma_len(&dma->sg[0]) = buf_len;
+	sg_dma_address(&dma->sg[0]) = dma_addr;
+
+	rxdesc = dmaengine_prep_slave_sg(chan_rx, dma->sg, 1, DMA_DEV_TO_MEM,
 					 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!rxdesc) {
 		dev_err(dev->dev, "dma prep slave sg failed\n");
@@ -370,7 +473,7 @@ static irqreturn_t atmel_twi_interrupt(int irq, void *dev_id)
 	/* catch error flags */
 	dev->transfer_status |= status;
 
-	if (irqstatus & AT91_TWI_TXCOMP) {
+	if (irqstatus & (AT91_TWI_TXCOMP | AT91_TWI_NACK)) {
 		at91_disable_twi_interrupts(dev);
 		complete(&dev->cmd_complete);
 	}
@@ -383,6 +486,50 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
 	int ret;
 	unsigned long time_left;
 	bool has_unre_flag = dev->pdata->has_unre_flag;
+	bool has_alt_cmd = dev->pdata->has_alt_cmd;
+
+	/*
+	 * WARNING: the TXCOMP bit in the Status Register is NOT a clear on
+	 * read flag but shows the state of the transmission at the time the
+	 * Status Register is read. According to the programmer datasheet,
+	 * TXCOMP is set when both holding register and internal shifter are
+	 * empty and STOP condition has been sent.
+	 * Consequently, we should enable NACK interrupt rather than TXCOMP to
+	 * detect transmission failure.
+	 * Indeed let's take the case of an i2c write command using DMA.
+	 * Whenever the slave doesn't acknowledge a byte, the LOCK, NACK and
+	 * TXCOMP bits are set together into the Status Register.
+	 * LOCK is a clear on write bit, which is set to prevent the DMA
+	 * controller from sending new data on the i2c bus after a NACK
+	 * condition has happened. Once locked, this i2c peripheral stops
+	 * triggering the DMA controller for new data but it is more than
+	 * likely that a new DMA transaction is already in progress, writing
+	 * into the Transmit Holding Register. Since the peripheral is locked,
+	 * these new data won't be sent to the i2c bus but they will remain
+	 * into the Transmit Holding Register, so TXCOMP bit is cleared.
+	 * Then when the interrupt handler is called, the Status Register is
+	 * read: the TXCOMP bit is clear but NACK bit is still set. The driver
+	 * manage the error properly, without waiting for timeout.
+	 * This case can be reproduced easyly when writing into an at24 eeprom.
+	 *
+	 * Besides, the TXCOMP bit is already set before the i2c transaction
+	 * has been started. For read transactions, this bit is cleared when
+	 * writing the START bit into the Control Register. So the
+	 * corresponding interrupt can safely be enabled just after.
+	 * However for write transactions managed by the CPU, we first write
+	 * into THR, so TXCOMP is cleared. Then we can safely enable TXCOMP
+	 * interrupt. If TXCOMP interrupt were enabled before writing into THR,
+	 * the interrupt handler would be called immediately and the i2c command
+	 * would be reported as completed.
+	 * Also when a write transaction is managed by the DMA controller,
+	 * enabling the TXCOMP interrupt in this function may lead to a race
+	 * condition since we don't know whether the TXCOMP interrupt is enabled
+	 * before or after the DMA has started to write into THR. So the TXCOMP
+	 * interrupt is enabled later by at91_twi_write_data_dma_callback().
+	 * Immediately after in that DMA callback, if the alternative command
+	 * mode is not used, we still need to send the STOP condition manually
+	 * writing the corresponding bit into the Control Register.
+	 */
 
 	dev_dbg(dev->dev, "transfer: %s %d bytes.\n",
 		(dev->msg->flags & I2C_M_RD) ? "read" : "write", dev->buf_len);
@@ -390,6 +537,21 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
 	reinit_completion(&dev->cmd_complete);
 	dev->transfer_status = 0;
 
+	if (dev->fifo_size) {
+		unsigned fifo_mr = at91_twi_read(dev, AT91_TWI_FMR);
+
+		/* Reset FIFO mode register */
+		fifo_mr &= ~(AT91_TWI_FMR_TXRDYM_MASK |
+			     AT91_TWI_FMR_RXRDYM_MASK);
+		fifo_mr |= AT91_TWI_FMR_TXRDYM(AT91_TWI_ONE_DATA);
+		fifo_mr |= AT91_TWI_FMR_RXRDYM(AT91_TWI_ONE_DATA);
+		at91_twi_write(dev, AT91_TWI_FMR, fifo_mr);
+
+		/* Flush FIFOs */
+		at91_twi_write(dev, AT91_TWI_CR,
+			       AT91_TWI_THRCLR | AT91_TWI_RHRCLR);
+	}
+
 	if (!dev->buf_len) {
 		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_QUICK);
 		at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_TXCOMP);
@@ -402,44 +564,45 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
 		}
 
 		/* if only one byte is to be read, immediately stop transfer */
-		if (dev->buf_len <= 1 && !(dev->msg->flags & I2C_M_RECV_LEN))
+		if (!has_alt_cmd && dev->buf_len <= 1 &&
+		    !(dev->msg->flags & I2C_M_RECV_LEN))
 			start_flags |= AT91_TWI_STOP;
 		at91_twi_write(dev, AT91_TWI_CR, start_flags);
 		/*
-		 * When using dma, the last byte has to be read manually in
-		 * order to not send the stop command too late and then
-		 * to receive extra data. In practice, there are some issues
-		 * if you use the dma to read n-1 bytes because of latency.
+		 * When using dma without alternative command mode, the last
+		 * byte has to be read manually in order to not send the stop
+		 * command too late and then to receive extra data.
+		 * In practice, there are some issues if you use the dma to
+		 * read n-1 bytes because of latency.
 		 * Reading n-2 bytes with dma and the two last ones manually
 		 * seems to be the best solution.
 		 */
 		if (dev->use_dma && (dev->buf_len > AT91_I2C_DMA_THRESHOLD)) {
+			at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_NACK);
 			at91_twi_read_data_dma(dev);
-			/*
-			 * It is important to enable TXCOMP irq here because
-			 * doing it only when transferring the last two bytes
-			 * will mask NACK errors since TXCOMP is set when a
-			 * NACK occurs.
-			 */
-			at91_twi_write(dev, AT91_TWI_IER,
-			       AT91_TWI_TXCOMP);
-		} else
+		} else {
 			at91_twi_write(dev, AT91_TWI_IER,
-			       AT91_TWI_TXCOMP | AT91_TWI_RXRDY);
+				       AT91_TWI_TXCOMP |
+				       AT91_TWI_NACK |
+				       AT91_TWI_RXRDY);
+		}
 	} else {
 		if (dev->use_dma && (dev->buf_len > AT91_I2C_DMA_THRESHOLD)) {
+			at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_NACK);
 			at91_twi_write_data_dma(dev);
-			at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_TXCOMP);
 		} else {
 			at91_twi_write_next_byte(dev);
 			at91_twi_write(dev, AT91_TWI_IER,
-				AT91_TWI_TXCOMP | AT91_TWI_TXRDY);
+				       AT91_TWI_TXCOMP |
+				       AT91_TWI_NACK |
+				       AT91_TWI_TXRDY);
 		}
 	}
 
 	time_left = wait_for_completion_timeout(&dev->cmd_complete,
 					      dev->adapter.timeout);
 	if (time_left == 0) {
+		dev->transfer_status |= at91_twi_read(dev, AT91_TWI_SR);
 		dev_err(dev->dev, "controller timed out\n");
 		at91_init_twi_bus(dev);
 		ret = -ETIMEDOUT;
@@ -460,6 +623,12 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
 		ret = -EIO;
 		goto error;
 	}
+	if ((has_alt_cmd || dev->fifo_size) &&
+	    (dev->transfer_status & AT91_TWI_LOCK)) {
+		dev_err(dev->dev, "tx locked\n");
+		ret = -EIO;
+		goto error;
+	}
 	if (dev->recv_len_abort) {
 		dev_err(dev->dev, "invalid smbus block length recvd\n");
 		ret = -EPROTO;
@@ -471,7 +640,15 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
 	return 0;
 
 error:
+	/* first stop DMA transfer if still in progress */
 	at91_twi_dma_cleanup(dev);
+	/* then flush THR/FIFO and unlock TX if locked */
+	if ((has_alt_cmd || dev->fifo_size) &&
+	    (dev->transfer_status & AT91_TWI_LOCK)) {
+		dev_dbg(dev->dev, "unlock tx\n");
+		at91_twi_write(dev, AT91_TWI_CR,
+			       AT91_TWI_THRCLR | AT91_TWI_LOCKCLR);
+	}
 	return ret;
 }
 
@@ -481,6 +658,7 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num)
 	int ret;
 	unsigned int_addr_flag = 0;
 	struct i2c_msg *m_start = msg;
+	bool is_read, use_alt_cmd = false;
 
 	dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num);
 
@@ -503,8 +681,23 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num)
 		at91_twi_write(dev, AT91_TWI_IADR, internal_address);
 	}
 
-	at91_twi_write(dev, AT91_TWI_MMR, (m_start->addr << 16) | int_addr_flag
-		       | ((m_start->flags & I2C_M_RD) ? AT91_TWI_MREAD : 0));
+	is_read = (m_start->flags & I2C_M_RD);
+	if (dev->pdata->has_alt_cmd) {
+		if (m_start->len > 0) {
+			at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_ACMEN);
+			at91_twi_write(dev, AT91_TWI_ACR,
+				       AT91_TWI_ACR_DATAL(m_start->len) |
+				       ((is_read) ? AT91_TWI_ACR_DIR : 0));
+			use_alt_cmd = true;
+		} else {
+			at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_ACMDIS);
+		}
+	}
+
+	at91_twi_write(dev, AT91_TWI_MMR,
+		       (m_start->addr << 16) |
+		       int_addr_flag |
+		       ((!use_alt_cmd && is_read) ? AT91_TWI_MREAD : 0));
 
 	dev->buf_len = m_start->len;
 	dev->buf = m_start->buf;
@@ -545,30 +738,35 @@ static struct at91_twi_pdata at91rm9200_config = {
 	.clk_max_div = 5,
 	.clk_offset = 3,
 	.has_unre_flag = true,
+	.has_alt_cmd = false,
 };
 
 static struct at91_twi_pdata at91sam9261_config = {
 	.clk_max_div = 5,
 	.clk_offset = 4,
 	.has_unre_flag = false,
+	.has_alt_cmd = false,
 };
 
 static struct at91_twi_pdata at91sam9260_config = {
 	.clk_max_div = 7,
 	.clk_offset = 4,
 	.has_unre_flag = false,
+	.has_alt_cmd = false,
 };
 
 static struct at91_twi_pdata at91sam9g20_config = {
 	.clk_max_div = 7,
 	.clk_offset = 4,
 	.has_unre_flag = false,
+	.has_alt_cmd = false,
 };
 
 static struct at91_twi_pdata at91sam9g10_config = {
 	.clk_max_div = 7,
 	.clk_offset = 4,
 	.has_unre_flag = false,
+	.has_alt_cmd = false,
 };
 
 static const struct platform_device_id at91_twi_devtypes[] = {
@@ -597,6 +795,14 @@ static struct at91_twi_pdata at91sam9x5_config = {
 	.clk_max_div = 7,
 	.clk_offset = 4,
 	.has_unre_flag = false,
+	.has_alt_cmd = false,
+};
+
+static struct at91_twi_pdata sama5d2_config = {
+	.clk_max_div = 7,
+	.clk_offset = 4,
+	.has_unre_flag = true,
+	.has_alt_cmd = true,
 };
 
 static const struct of_device_id atmel_twi_dt_ids[] = {
@@ -618,6 +824,9 @@ static const struct of_device_id atmel_twi_dt_ids[] = {
 	}, {
 		.compatible = "atmel,at91sam9x5-i2c",
 		.data = &at91sam9x5_config,
+	}, {
+		.compatible = "atmel,sama5d2-i2c",
+		.data = &sama5d2_config,
 	}, {
 		/* sentinel */
 	}
@@ -630,13 +839,32 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr)
 	int ret = 0;
 	struct dma_slave_config slave_config;
 	struct at91_twi_dma *dma = &dev->dma;
+	enum dma_slave_buswidth addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+
+	/*
+	 * The actual width of the access will be chosen in
+	 * dmaengine_prep_slave_sg():
+	 * for each buffer in the scatter-gather list, if its size is aligned
+	 * to addr_width then addr_width accesses will be performed to transfer
+	 * the buffer. On the other hand, if the buffer size is not aligned to
+	 * addr_width then the buffer is transferred using single byte accesses.
+	 * Please refer to the Atmel eXtended DMA controller driver.
+	 * When FIFOs are used, the TXRDYM threshold can always be set to
+	 * trigger the XDMAC when at least 4 data can be written into the TX
+	 * FIFO, even if single byte accesses are performed.
+	 * However the RXRDYM threshold must be set to fit the access width,
+	 * deduced from buffer length, so the XDMAC is triggered properly to
+	 * read data from the RX FIFO.
+	 */
+	if (dev->fifo_size)
+		addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 
 	memset(&slave_config, 0, sizeof(slave_config));
 	slave_config.src_addr = (dma_addr_t)phy_addr + AT91_TWI_RHR;
-	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	slave_config.src_addr_width = addr_width;
 	slave_config.src_maxburst = 1;
 	slave_config.dst_addr = (dma_addr_t)phy_addr + AT91_TWI_THR;
-	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	slave_config.dst_addr_width = addr_width;
 	slave_config.dst_maxburst = 1;
 	slave_config.device_fc = false;
 
@@ -668,7 +896,7 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr)
 		goto error;
 	}
 
-	sg_init_table(&dma->sg, 1);
+	sg_init_table(dma->sg, 2);
 	dma->buf_mapped = false;
 	dma->xfer_in_progress = false;
 	dev->use_dma = true;
@@ -754,6 +982,11 @@ static int at91_twi_probe(struct platform_device *pdev)
 			return rc;
 	}
 
+	if (!of_property_read_u32(pdev->dev.of_node, "atmel,fifo-size",
+				  &dev->fifo_size)) {
+		dev_info(dev->dev, "Using FIFO (%u data)\n", dev->fifo_size);
+	}
+
 	rc = of_property_read_u32(dev->dev->of_node, "clock-frequency",
 			&bus_clk_rate);
 	if (rc)
@@ -790,7 +1023,8 @@ static int at91_twi_probe(struct platform_device *pdev)
 		return rc;
 	}
 
-	dev_info(dev->dev, "AT91 i2c bus driver.\n");
+	dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n",
+		 at91_twi_read(dev, AT91_TWI_VER));
 	return 0;
 }
 

drivers/i2c/busses/i2c-axxia.c

@@ -42,6 +42,10 @@
 #define IBML_LOW_SEXT		0x18
 #define TIMER_CLOCK_DIV		0x1c
 #define I2C_BUS_MONITOR		0x20
+#define   BM_SDAC		BIT(3)
+#define   BM_SCLC		BIT(2)
+#define   BM_SDAS		BIT(1)
+#define   BM_SCLS		BIT(0)
 #define SOFT_RESET		0x24
 #define MST_COMMAND		0x28
 #define   CMD_BUSY		(1<<3)
@@ -394,6 +398,9 @@ static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
 	if (time_left == 0)
 		idev->msg_err = -ETIMEDOUT;
 
+	if (idev->msg_err == -ETIMEDOUT)
+		i2c_recover_bus(&idev->adapter);
+
 	if (unlikely(idev->msg_err) && idev->msg_err != -ENXIO)
 		axxia_i2c_init(idev);
 
@@ -437,6 +444,39 @@ axxia_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	return ret ? : i;
 }
 
+static int axxia_i2c_get_scl(struct i2c_adapter *adap)
+{
+	struct axxia_i2c_dev *idev = i2c_get_adapdata(adap);
+
+	return !!(readl(idev->base + I2C_BUS_MONITOR) & BM_SCLS);
+}
+
+static void axxia_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+	struct axxia_i2c_dev *idev = i2c_get_adapdata(adap);
+	u32 tmp;
+
+	/* Preserve SDA Control */
+	tmp = readl(idev->base + I2C_BUS_MONITOR) & BM_SDAC;
+	if (!val)
+		tmp |= BM_SCLC;
+	writel(tmp, idev->base + I2C_BUS_MONITOR);
+}
+
+static int axxia_i2c_get_sda(struct i2c_adapter *adap)
+{
+	struct axxia_i2c_dev *idev = i2c_get_adapdata(adap);
+
+	return !!(readl(idev->base + I2C_BUS_MONITOR) & BM_SDAS);
+}
+
+static struct i2c_bus_recovery_info axxia_i2c_recovery_info = {
+	.recover_bus = i2c_generic_scl_recovery,
+	.get_scl = axxia_i2c_get_scl,
+	.set_scl = axxia_i2c_set_scl,
+	.get_sda = axxia_i2c_get_sda,
+};
+
 static u32 axxia_i2c_func(struct i2c_adapter *adap)
 {
 	u32 caps = (I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR |
@@ -511,6 +551,7 @@ static int axxia_i2c_probe(struct platform_device *pdev)
 	strlcpy(idev->adapter.name, pdev->name, sizeof(idev->adapter.name));
 	idev->adapter.owner = THIS_MODULE;
 	idev->adapter.algo = &axxia_i2c_algo;
+	idev->adapter.bus_recovery_info = &axxia_i2c_recovery_info;
 	idev->adapter.quirks = &axxia_i2c_quirks;
 	idev->adapter.dev.parent = &pdev->dev;
 	idev->adapter.dev.of_node = pdev->dev.of_node;

drivers/i2c/busses/i2c-bcm-iproc.c

@@ -91,6 +91,7 @@ struct bcm_iproc_i2c_dev {
 	void __iomem *base;
 
 	struct i2c_adapter adapter;
+	unsigned int bus_speed;
 
 	struct completion done;
 	int xfer_is_done;
@@ -309,6 +310,7 @@ static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c)
 		bus_speed = 400000;
 	}
 
+	iproc_i2c->bus_speed = bus_speed;
 	val = readl(iproc_i2c->base + TIM_CFG_OFFSET);
 	val &= ~(1 << TIM_CFG_MODE_400_SHIFT);
 	val |= (bus_speed == 400000) << TIM_CFG_MODE_400_SHIFT;
@@ -439,6 +441,60 @@ static int bcm_iproc_i2c_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+
+static int bcm_iproc_i2c_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev);
+
+	/* make sure there's no pending interrupt when we go into suspend */
+	writel(0, iproc_i2c->base + IE_OFFSET);
+	readl(iproc_i2c->base + IE_OFFSET);
+	synchronize_irq(iproc_i2c->irq);
+
+	/* now disable the controller */
+	bcm_iproc_i2c_enable_disable(iproc_i2c, false);
+
+	return 0;
+}
+
+static int bcm_iproc_i2c_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev);
+	int ret;
+	u32 val;
+
+	/*
+	 * Power domain could have been shut off completely in system deep
+	 * sleep, so re-initialize the block here
+	 */
+	ret = bcm_iproc_i2c_init(iproc_i2c);
+	if (ret)
+		return ret;
+
+	/* configure to the desired bus speed */
+	val = readl(iproc_i2c->base + TIM_CFG_OFFSET);
+	val &= ~(1 << TIM_CFG_MODE_400_SHIFT);
+	val |= (iproc_i2c->bus_speed == 400000) << TIM_CFG_MODE_400_SHIFT;
+	writel(val, iproc_i2c->base + TIM_CFG_OFFSET);
+
+	bcm_iproc_i2c_enable_disable(iproc_i2c, true);
+
+	return 0;
+}
+
+static const struct dev_pm_ops bcm_iproc_i2c_pm_ops = {
+	.suspend_late = &bcm_iproc_i2c_suspend,
+	.resume_early = &bcm_iproc_i2c_resume
+};
+
+#define BCM_IPROC_I2C_PM_OPS (&bcm_iproc_i2c_pm_ops)
+#else
+#define BCM_IPROC_I2C_PM_OPS NULL
+#endif /* CONFIG_PM_SLEEP */
+
 static const struct of_device_id bcm_iproc_i2c_of_match[] = {
 	{ .compatible = "brcm,iproc-i2c" },
 	{ /* sentinel */ }
@@ -449,6 +505,7 @@ static struct platform_driver bcm_iproc_i2c_driver = {
 	.driver = {
 		.name = "bcm-iproc-i2c",
 		.of_match_table = bcm_iproc_i2c_of_match,
+		.pm = BCM_IPROC_I2C_PM_OPS,
 	},
 	.probe = bcm_iproc_i2c_probe,
 	.remove = bcm_iproc_i2c_remove,

drivers/i2c/busses/i2c-bcm2835.c

@@ -50,6 +50,11 @@
 #define BCM2835_I2C_S_CLKT	BIT(9)
 #define BCM2835_I2C_S_LEN	BIT(10) /* Fake bit for SW error reporting */
 
+#define BCM2835_I2C_BITMSK_S	0x03FF
+
+#define BCM2835_I2C_CDIV_MIN	0x0002
+#define BCM2835_I2C_CDIV_MAX	0xFFFE
+
 #define BCM2835_I2C_TIMEOUT (msecs_to_jiffies(1000))
 
 struct bcm2835_i2c_dev {
@@ -111,6 +116,7 @@ static irqreturn_t bcm2835_i2c_isr(int this_irq, void *data)
 	u32 val, err;
 
 	val = bcm2835_i2c_readl(i2c_dev, BCM2835_I2C_S);
+	val &= BCM2835_I2C_BITMSK_S;
 	bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_S, val);
 
 	err = val & (BCM2835_I2C_S_CLKT | BCM2835_I2C_S_ERR);
@@ -258,6 +264,11 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
 	 */
 	if (divider & 1)
 		divider++;
+	if ((divider < BCM2835_I2C_CDIV_MIN) ||
+	    (divider > BCM2835_I2C_CDIV_MAX)) {
+		dev_err(&pdev->dev, "Invalid clock-frequency\n");
+		return -ENODEV;
+	}
 	bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_DIV, divider);
 
 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);

drivers/i2c/busses/i2c-brcmstb.c

+/*
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/version.h>
+
+#define N_DATA_REGS					8
+#define N_DATA_BYTES					(N_DATA_REGS * 4)
+
+/* BSC count register field definitions */
+#define BSC_CNT_REG1_MASK				0x0000003f
+#define BSC_CNT_REG1_SHIFT				0
+#define BSC_CNT_REG2_MASK				0x00000fc0
+#define BSC_CNT_REG2_SHIFT				6
+
+/* BSC CTL register field definitions */
+#define BSC_CTL_REG_DTF_MASK				0x00000003
+#define BSC_CTL_REG_SCL_SEL_MASK			0x00000030
+#define BSC_CTL_REG_SCL_SEL_SHIFT			4
+#define BSC_CTL_REG_INT_EN_MASK				0x00000040
+#define BSC_CTL_REG_INT_EN_SHIFT			6
+#define BSC_CTL_REG_DIV_CLK_MASK			0x00000080
+
+/* BSC_IIC_ENABLE r/w enable and interrupt field defintions */
+#define BSC_IIC_EN_RESTART_MASK				0x00000040
+#define BSC_IIC_EN_NOSTART_MASK				0x00000020
+#define BSC_IIC_EN_NOSTOP_MASK				0x00000010
+#define BSC_IIC_EN_NOACK_MASK				0x00000004
+#define BSC_IIC_EN_INTRP_MASK				0x00000002
+#define BSC_IIC_EN_ENABLE_MASK				0x00000001
+
+/* BSC_CTLHI control register field definitions */
+#define BSC_CTLHI_REG_INPUT_SWITCHING_LEVEL_MASK	0x00000080
+#define BSC_CTLHI_REG_DATAREG_SIZE_MASK			0x00000040
+#define BSC_CTLHI_REG_IGNORE_ACK_MASK			0x00000002
+#define BSC_CTLHI_REG_WAIT_DIS_MASK			0x00000001
+
+#define I2C_TIMEOUT					100 /* msecs */
+
+/* Condition mask used for non combined transfer */
+#define COND_RESTART		BSC_IIC_EN_RESTART_MASK
+#define COND_NOSTART		BSC_IIC_EN_NOSTART_MASK
+#define COND_NOSTOP		BSC_IIC_EN_NOSTOP_MASK
+#define COND_START_STOP		(COND_RESTART | COND_NOSTART | COND_NOSTOP)
+
+/* BSC data transfer direction */
+#define DTF_WR_MASK		0x00000000
+#define DTF_RD_MASK		0x00000001
+/* BSC data transfer direction combined format */
+#define DTF_RD_WR_MASK		0x00000002
+#define DTF_WR_RD_MASK		0x00000003
+
+#define INT_ENABLE		true
+#define INT_DISABLE		false
+
+/* BSC block register map structure to cache fields to be written */
+struct bsc_regs {
+	u32	chip_address;           /* slave address */
+	u32	data_in[N_DATA_REGS];   /* tx data buffer*/
+	u32	cnt_reg;		/* rx/tx data length */
+	u32	ctl_reg;		/* control register */
+	u32	iic_enable;		/* xfer enable and status */
+	u32	data_out[N_DATA_REGS];  /* rx data buffer */
+	u32	ctlhi_reg;		/* more control fields */
+	u32	scl_param;		/* reserved */
+};
+
+struct bsc_clk_param {
+	u32 hz;
+	u32 scl_mask;
+	u32 div_mask;
+};
+
+enum bsc_xfer_cmd {
+	CMD_WR,
+	CMD_RD,
+	CMD_WR_NOACK,
+	CMD_RD_NOACK,
+};
+
+static char const *cmd_string[] = {
+	[CMD_WR] = "WR",
+	[CMD_RD] = "RD",
+	[CMD_WR_NOACK] = "WR NOACK",
+	[CMD_RD_NOACK] = "RD NOACK",
+};
+
+enum bus_speeds {
+	SPD_375K,
+	SPD_390K,
+	SPD_187K,
+	SPD_200K,
+	SPD_93K,
+	SPD_97K,
+	SPD_46K,
+	SPD_50K
+};
+
+static const struct bsc_clk_param bsc_clk[] = {
+	[SPD_375K] = {
+		.hz = 375000,
+		.scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = 0
+	},
+	[SPD_390K] = {
+		.hz = 390000,
+		.scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = 0
+	},
+	[SPD_187K] = {
+		.hz = 187500,
+		.scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = 0
+	},
+	[SPD_200K] = {
+		.hz = 200000,
+		.scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = 0
+	},
+	[SPD_93K]  = {
+		.hz = 93750,
+		.scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
+	},
+	[SPD_97K]  = {
+		.hz = 97500,
+		.scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
+	},
+	[SPD_46K]  = {
+		.hz = 46875,
+		.scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
+	},
+	[SPD_50K]  = {
+		.hz = 50000,
+		.scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
+	}
+};
+
+struct brcmstb_i2c_dev {
+	struct device *device;
+	void __iomem *base;
+	void __iomem *irq_base;
+	int irq;
+	struct bsc_regs *bsc_regmap;
+	struct i2c_adapter adapter;
+	struct completion done;
+	bool is_suspended;
+	u32 clk_freq_hz;
+};
+
+/* register accessors for both be and le cpu arch */
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define __bsc_readl(_reg) ioread32be(_reg)
+#define __bsc_writel(_val, _reg) iowrite32be(_val, _reg)
+#else
+#define __bsc_readl(_reg) ioread32(_reg)
+#define __bsc_writel(_val, _reg) iowrite32(_val, _reg)
+#endif
+
+#define bsc_readl(_dev, _reg)						\
+	__bsc_readl(_dev->base + offsetof(struct bsc_regs, _reg))
+
+#define bsc_writel(_dev, _val, _reg)					\
+	__bsc_writel(_val, _dev->base + offsetof(struct bsc_regs, _reg))
+
+static void brcmstb_i2c_enable_disable_irq(struct brcmstb_i2c_dev *dev,
+					   bool int_en)
+{
+
+	if (int_en)
+		/* Enable BSC  CTL interrupt line */
+		dev->bsc_regmap->ctl_reg |= BSC_CTL_REG_INT_EN_MASK;
+	else
+		/* Disable BSC CTL interrupt line */
+		dev->bsc_regmap->ctl_reg &= ~BSC_CTL_REG_INT_EN_MASK;
+
+	barrier();
+	bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
+}
+
+static irqreturn_t brcmstb_i2c_isr(int irq, void *devid)
+{
+	struct brcmstb_i2c_dev *dev = devid;
+	u32 status_bsc_ctl = bsc_readl(dev, ctl_reg);
+	u32 status_iic_intrp = bsc_readl(dev, iic_enable);
+
+	dev_dbg(dev->device, "isr CTL_REG %x IIC_EN %x\n",
+		status_bsc_ctl, status_iic_intrp);
+
+	if (!(status_bsc_ctl & BSC_CTL_REG_INT_EN_MASK))
+		return IRQ_NONE;
+
+	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
+	complete_all(&dev->done);
+
+	dev_dbg(dev->device, "isr handled");
+	return IRQ_HANDLED;
+}
+
+/* Wait for device to be ready */
+static int brcmstb_i2c_wait_if_busy(struct brcmstb_i2c_dev *dev)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
+
+	while ((bsc_readl(dev, iic_enable) & BSC_IIC_EN_INTRP_MASK)) {
+		if (time_after(jiffies, timeout))
+			return -ETIMEDOUT;
+		cpu_relax();
+	}
+	return 0;
+}
+
+/* i2c xfer completion function, handles both irq and polling mode */
+static int brcmstb_i2c_wait_for_completion(struct brcmstb_i2c_dev *dev)
+{
+	int ret = 0;
+	unsigned long timeout = msecs_to_jiffies(I2C_TIMEOUT);
+
+	if (dev->irq >= 0) {
+		if (!wait_for_completion_timeout(&dev->done, timeout))
+			ret = -ETIMEDOUT;
+	} else {
+		/* we are in polling mode */
+		u32 bsc_intrp;
+		unsigned long time_left = jiffies + timeout;
+
+		do {
+			bsc_intrp = bsc_readl(dev, iic_enable) &
+				BSC_IIC_EN_INTRP_MASK;
+			if (time_after(jiffies, time_left)) {
+				ret = -ETIMEDOUT;
+				break;
+			}
+			cpu_relax();
+		} while (!bsc_intrp);
+	}
+
+	if (dev->irq < 0 || ret == -ETIMEDOUT)
+		brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
+
+	return ret;
+}
+
+/* Set xfer START/STOP conditions for subsequent transfer */
+static void brcmstb_set_i2c_start_stop(struct brcmstb_i2c_dev *dev,
+				       u32 cond_flag)
+{
+	u32 regval = dev->bsc_regmap->iic_enable;
+
+	dev->bsc_regmap->iic_enable = (regval & ~COND_START_STOP) | cond_flag;
+}
+
+/* Send I2C request check completion */
+static int brcmstb_send_i2c_cmd(struct brcmstb_i2c_dev *dev,
+				enum bsc_xfer_cmd cmd)
+{
+	int rc = 0;
+	struct bsc_regs *pi2creg = dev->bsc_regmap;
+
+	/* Make sure the hardware is ready */
+	rc = brcmstb_i2c_wait_if_busy(dev);
+	if (rc < 0)
+		return rc;
+
+	/* only if we are in interrupt mode */
+	if (dev->irq >= 0)
+		reinit_completion(&dev->done);
+
+	/* enable BSC CTL interrupt line */
+	brcmstb_i2c_enable_disable_irq(dev, INT_ENABLE);
+
+	/* initiate transfer by setting iic_enable */
+	pi2creg->iic_enable |= BSC_IIC_EN_ENABLE_MASK;
+	bsc_writel(dev, pi2creg->iic_enable, iic_enable);
+
+	/* Wait for transaction to finish or timeout */
+	rc = brcmstb_i2c_wait_for_completion(dev);
+	if (rc) {
+		dev_dbg(dev->device, "intr timeout for cmd %s\n",
+			cmd_string[cmd]);
+		goto cmd_out;
+	}
+
+	if ((CMD_RD || CMD_WR) &&
+	    bsc_readl(dev, iic_enable) & BSC_IIC_EN_NOACK_MASK) {
+		rc = -EREMOTEIO;
+		dev_dbg(dev->device, "controller received NOACK intr for %s\n",
+			cmd_string[cmd]);
+	}
+
+cmd_out:
+	bsc_writel(dev, 0, cnt_reg);
+	bsc_writel(dev, 0, iic_enable);
+
+	return rc;
+}
+
+/* Actual data transfer through the BSC master */
+static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev,
+				     u8 *buf, unsigned int len,
+				     struct i2c_msg *pmsg)
+{
+	int cnt, byte, rc;
+	enum bsc_xfer_cmd cmd;
+	u32 ctl_reg;
+	struct bsc_regs *pi2creg = dev->bsc_regmap;
+	int no_ack = pmsg->flags & I2C_M_IGNORE_NAK;
+
+	/* see if the transaction needs to check NACK conditions */
+	if (no_ack || len <= N_DATA_BYTES) {
+		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD_NOACK
+			: CMD_WR_NOACK;
+		pi2creg->ctlhi_reg |= BSC_CTLHI_REG_IGNORE_ACK_MASK;
+	} else {
+		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD : CMD_WR;
+		pi2creg->ctlhi_reg &= ~BSC_CTLHI_REG_IGNORE_ACK_MASK;
+	}
+	bsc_writel(dev, pi2creg->ctlhi_reg, ctlhi_reg);
+
+	/* set data transfer direction */
+	ctl_reg = pi2creg->ctl_reg & ~BSC_CTL_REG_DTF_MASK;
+	if (cmd == CMD_WR || cmd == CMD_WR_NOACK)
+		pi2creg->ctl_reg = ctl_reg | DTF_WR_MASK;
+	else
+		pi2creg->ctl_reg = ctl_reg | DTF_RD_MASK;
+
+	/* set the read/write length */
+	bsc_writel(dev, BSC_CNT_REG1_MASK & (len << BSC_CNT_REG1_SHIFT),
+		   cnt_reg);
+
+	/* Write data into data_in register */
+	if (cmd == CMD_WR || cmd == CMD_WR_NOACK) {
+		for (cnt = 0; cnt < len; cnt += 4) {
+			u32 word = 0;
+
+			for (byte = 0; byte < 4; byte++) {
+				word >>= 8;
+				if ((cnt + byte) < len)
+					word |= buf[cnt + byte] << 24;
+			}
+			bsc_writel(dev, word, data_in[cnt >> 2]);
+		}
+	}
+
+	/* Initiate xfer, the function will return on completion */
+	rc = brcmstb_send_i2c_cmd(dev, cmd);
+
+	if (rc != 0) {
+		dev_dbg(dev->device, "%s failure", cmd_string[cmd]);
+		return rc;
+	}
+
+	if (cmd == CMD_RD || cmd == CMD_RD_NOACK) {
+		for (cnt = 0; cnt < len; cnt += 4) {
+			u32 data = bsc_readl(dev, data_out[cnt >> 2]);
+
+			for (byte = 0; byte < 4 &&
+				     (byte + cnt) < len; byte++) {
+				buf[cnt + byte] = data & 0xff;
+				data >>= 8;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/* Write a single byte of data to the i2c bus */
+static int brcmstb_i2c_write_data_byte(struct brcmstb_i2c_dev *dev,
+				       u8 *buf, unsigned int nak_expected)
+{
+	enum bsc_xfer_cmd cmd = nak_expected ? CMD_WR : CMD_WR_NOACK;
+
+	bsc_writel(dev, 1, cnt_reg);
+	bsc_writel(dev, *buf, data_in);
+
+	return brcmstb_send_i2c_cmd(dev, cmd);
+}
+
+/* Send i2c address */
+static int brcmstb_i2c_do_addr(struct brcmstb_i2c_dev *dev,
+			       struct i2c_msg *msg)
+{
+	unsigned char addr;
+
+	if (msg->flags & I2C_M_TEN) {
+		/* First byte is 11110XX0 where XX is upper 2 bits */
+		addr = 0xF0 | ((msg->addr & 0x300) >> 7);
+		bsc_writel(dev, addr, chip_address);
+
+		/* Second byte is the remaining 8 bits */
+		addr = msg->addr & 0xFF;
+		if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
+			return -EREMOTEIO;
+
+		if (msg->flags & I2C_M_RD) {
+			/* For read, send restart without stop condition */
+			brcmstb_set_i2c_start_stop(dev, COND_RESTART
+						   | COND_NOSTOP);
+			/* Then re-send the first byte with the read bit set */
+			addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
+			if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
+				return -EREMOTEIO;
+
+		}
+	} else {
+		addr = msg->addr << 1;
+		if (msg->flags & I2C_M_RD)
+			addr |= 1;
+
+		bsc_writel(dev, addr, chip_address);
+	}
+
+	return 0;
+}
+
+/* Master transfer function */
+static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
+			    struct i2c_msg msgs[], int num)
+{
+	struct brcmstb_i2c_dev *dev = i2c_get_adapdata(adapter);
+	struct i2c_msg *pmsg;
+	int rc = 0;
+	int i;
+	int bytes_to_xfer;
+	u8 *tmp_buf;
+	int len = 0;
+
+	if (dev->is_suspended)
+		return -EBUSY;
+
+	/* Loop through all messages */
+	for (i = 0; i < num; i++) {
+		pmsg = &msgs[i];
+		len = pmsg->len;
+		tmp_buf = pmsg->buf;
+
+		dev_dbg(dev->device,
+			"msg# %d/%d flg %x buf %x len %d\n", i,
+			num - 1, pmsg->flags,
+			pmsg->buf ? pmsg->buf[0] : '0', pmsg->len);
+
+		if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART))
+			brcmstb_set_i2c_start_stop(dev, ~(COND_START_STOP));
+		else
+			brcmstb_set_i2c_start_stop(dev,
+						   COND_RESTART | COND_NOSTOP);
+
+		/* Send slave address */
+		if (!(pmsg->flags & I2C_M_NOSTART)) {
+			rc = brcmstb_i2c_do_addr(dev, pmsg);
+			if (rc < 0) {
+				dev_dbg(dev->device,
+					"NACK for addr %2.2x msg#%d rc = %d\n",
+					pmsg->addr, i, rc);
+				goto out;
+			}
+		}
+
+		/* Perform data transfer */
+		while (len) {
+			bytes_to_xfer = min(len, N_DATA_BYTES);
+
+			if (len <= N_DATA_BYTES && i == (num - 1))
+				brcmstb_set_i2c_start_stop(dev,
+							   ~(COND_START_STOP));
+
+			rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf,
+						       bytes_to_xfer, pmsg);
+			if (rc < 0)
+				goto out;
+
+			len -=  bytes_to_xfer;
+			tmp_buf += bytes_to_xfer;
+		}
+	}
+
+	rc = num;
+out:
+	return rc;
+
+}
+
+static u32 brcmstb_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR
+		| I2C_FUNC_NOSTART | I2C_FUNC_PROTOCOL_MANGLING;
+}
+
+static const struct i2c_algorithm brcmstb_i2c_algo = {
+	.master_xfer = brcmstb_i2c_xfer,
+	.functionality = brcmstb_i2c_functionality,
+};
+
+static void brcmstb_i2c_set_bus_speed(struct brcmstb_i2c_dev *dev)
+{
+	int i = 0, num_speeds = ARRAY_SIZE(bsc_clk);
+	u32 clk_freq_hz = dev->clk_freq_hz;
+
+	for (i = 0; i < num_speeds; i++) {
+		if (bsc_clk[i].hz == clk_freq_hz) {
+			dev->bsc_regmap->ctl_reg &= ~(BSC_CTL_REG_SCL_SEL_MASK
+						| BSC_CTL_REG_DIV_CLK_MASK);
+			dev->bsc_regmap->ctl_reg |= (bsc_clk[i].scl_mask |
+						     bsc_clk[i].div_mask);
+			bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
+			break;
+		}
+	}
+
+	/* in case we did not get find a valid speed */
+	if (i == num_speeds) {
+		i = (bsc_readl(dev, ctl_reg) & BSC_CTL_REG_SCL_SEL_MASK) >>
+			BSC_CTL_REG_SCL_SEL_SHIFT;
+		dev_warn(dev->device, "leaving current clock-frequency @ %dHz\n",
+			bsc_clk[i].hz);
+	}
+}
+
+static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev)
+{
+	/* 4 byte data register */
+	dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK;
+	bsc_writel(dev, dev->bsc_regmap->ctlhi_reg, ctlhi_reg);
+	/* set bus speed */
+	brcmstb_i2c_set_bus_speed(dev);
+}
+
+static int brcmstb_i2c_probe(struct platform_device *pdev)
+{
+	int rc = 0;
+	struct brcmstb_i2c_dev *dev;
+	struct i2c_adapter *adap;
+	struct resource *iomem;
+	const char *int_name;
+
+	/* Allocate memory for private data structure */
+	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	dev->bsc_regmap = devm_kzalloc(&pdev->dev, sizeof(struct bsc_regs *),
+				       GFP_KERNEL);
+	if (!dev->bsc_regmap)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, dev);
+	dev->device = &pdev->dev;
+	init_completion(&dev->done);
+
+	/* Map hardware registers */
+	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dev->base = devm_ioremap_resource(dev->device, iomem);
+	if (IS_ERR(dev->base)) {
+		rc = -ENOMEM;
+		goto probe_errorout;
+	}
+
+	rc = of_property_read_string(dev->device->of_node, "interrupt-names",
+				     &int_name);
+	if (rc < 0)
+		int_name = NULL;
+
+	/* Get the interrupt number */
+	dev->irq = platform_get_irq(pdev, 0);
+
+	/* disable the bsc interrupt line */
+	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
+
+	/* register the ISR handler */
+	rc = devm_request_irq(&pdev->dev, dev->irq, brcmstb_i2c_isr,
+			      IRQF_SHARED,
+			      int_name ? int_name : pdev->name,
+			      dev);
+
+	if (rc) {
+		dev_dbg(dev->device, "falling back to polling mode");
+		dev->irq = -1;
+	}
+
+	if (of_property_read_u32(dev->device->of_node,
+				 "clock-frequency", &dev->clk_freq_hz)) {
+		dev_warn(dev->device, "setting clock-frequency@%dHz\n",
+			 bsc_clk[0].hz);
+		dev->clk_freq_hz = bsc_clk[0].hz;
+	}
+
+	brcmstb_i2c_set_bsc_reg_defaults(dev);
+
+	/* Add the i2c adapter */
+	adap = &dev->adapter;
+	i2c_set_adapdata(adap, dev);
+	adap->owner = THIS_MODULE;
+	strlcpy(adap->name, "Broadcom STB : ", sizeof(adap->name));
+	if (int_name)
+		strlcat(adap->name, int_name, sizeof(adap->name));
+	adap->algo = &brcmstb_i2c_algo;
+	adap->dev.parent = &pdev->dev;
+	adap->dev.of_node = pdev->dev.of_node;
+	rc = i2c_add_adapter(adap);
+	if (rc) {
+		dev_err(dev->device, "failed to add adapter\n");
+		goto probe_errorout;
+	}
+
+	dev_info(dev->device, "%s@%dhz registered in %s mode\n",
+		 int_name ? int_name : " ", dev->clk_freq_hz,
+		 (dev->irq >= 0) ? "interrupt" : "polling");
+
+	return 0;
+
+probe_errorout:
+	return rc;
+}
+
+static int brcmstb_i2c_remove(struct platform_device *pdev)
+{
+	struct brcmstb_i2c_dev *dev = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&dev->adapter);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int brcmstb_i2c_suspend(struct device *dev)
+{
+	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
+
+	i2c_lock_adapter(&i2c_dev->adapter);
+	i2c_dev->is_suspended = true;
+	i2c_unlock_adapter(&i2c_dev->adapter);
+
+	return 0;
+}
+
+static int brcmstb_i2c_resume(struct device *dev)
+{
+	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
+
+	i2c_lock_adapter(&i2c_dev->adapter);
+	brcmstb_i2c_set_bsc_reg_defaults(i2c_dev);
+	i2c_dev->is_suspended = false;
+	i2c_unlock_adapter(&i2c_dev->adapter);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend,
+			 brcmstb_i2c_resume);
+
+static const struct of_device_id brcmstb_i2c_of_match[] = {
+	{.compatible = "brcm,brcmstb-i2c"},
+	{},
+};
+MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match);
+
+static struct platform_driver brcmstb_i2c_driver = {
+	.driver = {
+		   .name = "brcmstb-i2c",
+		   .of_match_table = brcmstb_i2c_of_match,
+		   .pm = &brcmstb_i2c_pm,
+		   },
+	.probe = brcmstb_i2c_probe,
+	.remove = brcmstb_i2c_remove,
+};
+module_platform_driver(brcmstb_i2c_driver);
+
+MODULE_AUTHOR("Kamal Dasu <kdasu@broadcom.com>");
+MODULE_DESCRIPTION("Broadcom Settop I2C Driver");
+MODULE_LICENSE("GPL v2");

drivers/i2c/busses/i2c-davinci.c

@@ -41,8 +41,8 @@
 
 #define DAVINCI_I2C_TIMEOUT	(1*HZ)
 #define DAVINCI_I2C_MAX_TRIES	2
-#define I2C_DAVINCI_INTR_ALL    (DAVINCI_I2C_IMR_AAS | \
-				 DAVINCI_I2C_IMR_SCD | \
+#define DAVINCI_I2C_OWN_ADDRESS	0x08
+#define I2C_DAVINCI_INTR_ALL    (DAVINCI_I2C_IMR_SCD | \
 				 DAVINCI_I2C_IMR_ARDY | \
 				 DAVINCI_I2C_IMR_NACK | \
 				 DAVINCI_I2C_IMR_AL)
@@ -204,9 +204,30 @@ static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
 		psc++;	/* better to run under spec than over */
 	d = (psc >= 2) ? 5 : 7 - psc;
 
-	clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)) - (d << 1);
-	clkh = clk >> 1;
-	clkl = clk - clkh;
+	clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000));
+	/* Avoid driving the bus too fast because of rounding errors above */
+	if (input_clock / (psc + 1) / clk > pdata->bus_freq * 1000)
+		clk++;
+	/*
+	 * According to I2C-BUS Spec 2.1, in FAST-MODE LOW period should be at
+	 * least 1.3uS, which is not the case with 50% duty cycle. Driving HIGH
+	 * to LOW ratio as 1 to 2 is more safe.
+	 */
+	if (pdata->bus_freq > 100)
+		clkl = (clk << 1) / 3;
+	else
+		clkl = (clk >> 1);
+	/*
+	 * It's not always possible to have 1 to 2 ratio when d=7, so fall back
+	 * to minimal possible clkh in this case.
+	 */
+	if (clk >= clkl + d) {
+		clkh = clk - clkl - d;
+		clkl -= d;
+	} else {
+		clkh = 0;
+		clkl = clk - (d << 1);
+	}
 
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_PSC_REG, psc);
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
@@ -233,7 +254,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
 	/* Respond at reserved "SMBus Host" slave address" (and zero);
 	 * we seem to have no option to not respond...
 	 */
-	davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, 0x08);
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, DAVINCI_I2C_OWN_ADDRESS);
 
 	dev_dbg(dev->dev, "PSC  = %d\n",
 		davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG));
@@ -350,29 +371,25 @@ static struct i2c_bus_recovery_info davinci_i2c_scl_recovery_info = {
 /*
  * Waiting for bus not busy
  */
-static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev,
-					 char allow_sleep)
+static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev)
 {
-	unsigned long timeout;
-	static u16 to_cnt;
-
-	timeout = jiffies + dev->adapter.timeout;
-	while (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG)
-	       & DAVINCI_I2C_STR_BB) {
-		if (to_cnt <= DAVINCI_I2C_MAX_TRIES) {
-			if (time_after(jiffies, timeout)) {
-				dev_warn(dev->dev,
-				"timeout waiting for bus ready\n");
-				to_cnt++;
-				return -ETIMEDOUT;
-			} else {
-				to_cnt = 0;
-				i2c_recover_bus(&dev->adapter);
-			}
-		}
-		if (allow_sleep)
-			schedule_timeout(1);
-	}
+	unsigned long timeout = jiffies + dev->adapter.timeout;
+
+	do {
+		if (!(davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB))
+			return 0;
+		schedule_timeout_uninterruptible(1);
+	} while (time_before_eq(jiffies, timeout));
+
+	dev_warn(dev->dev, "timeout waiting for bus ready\n");
+	i2c_recover_bus(&dev->adapter);
+
+	/*
+	 * if bus is still "busy" here, it's most probably a HW problem like
+	 * short-circuit
+	 */
+	if (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB)
+		return -EIO;
 
 	return 0;
 }
@@ -390,6 +407,11 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
 	u16 w;
 	unsigned long time_left;
 
+	if (msg->addr == DAVINCI_I2C_OWN_ADDRESS) {
+		dev_warn(dev->dev, "transfer to own address aborted\n");
+		return -EADDRNOTAVAIL;
+	}
+
 	/* Introduce a delay, required for some boards (e.g Davinci EVM) */
 	if (pdata->bus_delay)
 		udelay(pdata->bus_delay);
@@ -505,7 +527,7 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 
 	dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
 
-	ret = i2c_davinci_wait_bus_not_busy(dev, 1);
+	ret = i2c_davinci_wait_bus_not_busy(dev);
 	if (ret < 0) {
 		dev_warn(dev->dev, "timeout waiting for bus ready\n");
 		return ret;

drivers/i2c/busses/i2c-designware-platdrv.c

@@ -281,7 +281,8 @@ static int dw_i2c_remove(struct platform_device *pdev)
 
 	i2c_dw_disable(dev);
 
-	pm_runtime_put(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 
 	if (has_acpi_companion(&pdev->dev))
@@ -298,6 +299,22 @@ static const struct of_device_id dw_i2c_of_match[] = {
 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 #endif
 
+#ifdef CONFIG_PM_SLEEP
+static int dw_i2c_prepare(struct device *dev)
+{
+	return pm_runtime_suspended(dev);
+}
+
+static void dw_i2c_complete(struct device *dev)
+{
+	if (dev->power.direct_complete)
+		pm_request_resume(dev);
+}
+#else
+#define dw_i2c_prepare	NULL
+#define dw_i2c_complete	NULL
+#endif
+
 #ifdef CONFIG_PM
 static int dw_i2c_suspend(struct device *dev)
 {
@@ -322,10 +339,18 @@ static int dw_i2c_resume(struct device *dev)
 
 	return 0;
 }
-#endif
 
-static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend,
-			    dw_i2c_resume, NULL);
+static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
+	.prepare = dw_i2c_prepare,
+	.complete = dw_i2c_complete,
+	SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_suspend, dw_i2c_resume)
+	SET_RUNTIME_PM_OPS(dw_i2c_suspend, dw_i2c_resume, NULL)
+};
+
+#define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
+#else
+#define DW_I2C_DEV_PMOPS NULL
+#endif
 
 /* work with hotplug and coldplug */
 MODULE_ALIAS("platform:i2c_designware");
@@ -337,7 +362,7 @@ static struct platform_driver dw_i2c_driver = {
 		.name	= "i2c_designware",
 		.of_match_table = of_match_ptr(dw_i2c_of_match),
 		.acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
-		.pm	= &dw_i2c_dev_pm_ops,
+		.pm	= DW_I2C_DEV_PMOPS,
 	},
 };
 

drivers/i2c/busses/i2c-imx.c

@@ -241,7 +241,7 @@ static struct imx_i2c_hwdata vf610_i2c_hwdata = {
 
 };
 
-static struct platform_device_id imx_i2c_devtype[] = {
+static const struct platform_device_id imx_i2c_devtype[] = {
 	{
 		.name = "imx1-i2c",
 		.driver_data = (kernel_ulong_t)&imx1_i2c_hwdata,

drivers/i2c/busses/i2c-mt65xx.c

+/*
+ * Copyright (c) 2014 MediaTek Inc.
+ * Author: Xudong Chen <xudong.chen@mediatek.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#define I2C_RS_TRANSFER			(1 << 4)
+#define I2C_HS_NACKERR			(1 << 2)
+#define I2C_ACKERR			(1 << 1)
+#define I2C_TRANSAC_COMP		(1 << 0)
+#define I2C_TRANSAC_START		(1 << 0)
+#define I2C_RS_MUL_CNFG			(1 << 15)
+#define I2C_RS_MUL_TRIG			(1 << 14)
+#define I2C_DCM_DISABLE			0x0000
+#define I2C_IO_CONFIG_OPEN_DRAIN	0x0003
+#define I2C_IO_CONFIG_PUSH_PULL		0x0000
+#define I2C_SOFT_RST			0x0001
+#define I2C_FIFO_ADDR_CLR		0x0001
+#define I2C_DELAY_LEN			0x0002
+#define I2C_ST_START_CON		0x8001
+#define I2C_FS_START_CON		0x1800
+#define I2C_TIME_CLR_VALUE		0x0000
+#define I2C_TIME_DEFAULT_VALUE		0x0003
+#define I2C_FS_TIME_INIT_VALUE		0x1303
+#define I2C_WRRD_TRANAC_VALUE		0x0002
+#define I2C_RD_TRANAC_VALUE		0x0001
+
+#define I2C_DMA_CON_TX			0x0000
+#define I2C_DMA_CON_RX			0x0001
+#define I2C_DMA_START_EN		0x0001
+#define I2C_DMA_INT_FLAG_NONE		0x0000
+#define I2C_DMA_CLR_FLAG		0x0000
+
+#define I2C_DEFAULT_SPEED		100000	/* hz */
+#define MAX_FS_MODE_SPEED		400000
+#define MAX_HS_MODE_SPEED		3400000
+#define MAX_SAMPLE_CNT_DIV		8
+#define MAX_STEP_CNT_DIV		64
+#define MAX_HS_STEP_CNT_DIV		8
+
+#define I2C_CONTROL_RS                  (0x1 << 1)
+#define I2C_CONTROL_DMA_EN              (0x1 << 2)
+#define I2C_CONTROL_CLK_EXT_EN          (0x1 << 3)
+#define I2C_CONTROL_DIR_CHANGE          (0x1 << 4)
+#define I2C_CONTROL_ACKERR_DET_EN       (0x1 << 5)
+#define I2C_CONTROL_TRANSFER_LEN_CHANGE (0x1 << 6)
+#define I2C_CONTROL_WRAPPER             (0x1 << 0)
+
+#define I2C_DRV_NAME		"i2c-mt65xx"
+
+enum DMA_REGS_OFFSET {
+	OFFSET_INT_FLAG = 0x0,
+	OFFSET_INT_EN = 0x04,
+	OFFSET_EN = 0x08,
+	OFFSET_CON = 0x18,
+	OFFSET_TX_MEM_ADDR = 0x1c,
+	OFFSET_RX_MEM_ADDR = 0x20,
+	OFFSET_TX_LEN = 0x24,
+	OFFSET_RX_LEN = 0x28,
+};
+
+enum i2c_trans_st_rs {
+	I2C_TRANS_STOP = 0,
+	I2C_TRANS_REPEATED_START,
+};
+
+enum mtk_trans_op {
+	I2C_MASTER_WR = 1,
+	I2C_MASTER_RD,
+	I2C_MASTER_WRRD,
+};
+
+enum I2C_REGS_OFFSET {
+	OFFSET_DATA_PORT = 0x0,
+	OFFSET_SLAVE_ADDR = 0x04,
+	OFFSET_INTR_MASK = 0x08,
+	OFFSET_INTR_STAT = 0x0c,
+	OFFSET_CONTROL = 0x10,
+	OFFSET_TRANSFER_LEN = 0x14,
+	OFFSET_TRANSAC_LEN = 0x18,
+	OFFSET_DELAY_LEN = 0x1c,
+	OFFSET_TIMING = 0x20,
+	OFFSET_START = 0x24,
+	OFFSET_EXT_CONF = 0x28,
+	OFFSET_FIFO_STAT = 0x30,
+	OFFSET_FIFO_THRESH = 0x34,
+	OFFSET_FIFO_ADDR_CLR = 0x38,
+	OFFSET_IO_CONFIG = 0x40,
+	OFFSET_RSV_DEBUG = 0x44,
+	OFFSET_HS = 0x48,
+	OFFSET_SOFTRESET = 0x50,
+	OFFSET_DCM_EN = 0x54,
+	OFFSET_PATH_DIR = 0x60,
+	OFFSET_DEBUGSTAT = 0x64,
+	OFFSET_DEBUGCTRL = 0x68,
+	OFFSET_TRANSFER_LEN_AUX = 0x6c,
+};
+
+struct mtk_i2c_compatible {
+	const struct i2c_adapter_quirks *quirks;
+	unsigned char pmic_i2c: 1;
+	unsigned char dcm: 1;
+	unsigned char auto_restart: 1;
+};
+
+struct mtk_i2c {
+	struct i2c_adapter adap;	/* i2c host adapter */
+	struct device *dev;
+	struct completion msg_complete;
+
+	/* set in i2c probe */
+	void __iomem *base;		/* i2c base addr */
+	void __iomem *pdmabase;		/* dma base address*/
+	struct clk *clk_main;		/* main clock for i2c bus */
+	struct clk *clk_dma;		/* DMA clock for i2c via DMA */
+	struct clk *clk_pmic;		/* PMIC clock for i2c from PMIC */
+	bool have_pmic;			/* can use i2c pins from PMIC */
+	bool use_push_pull;		/* IO config push-pull mode */
+
+	u16 irq_stat;			/* interrupt status */
+	unsigned int speed_hz;		/* The speed in transfer */
+	enum mtk_trans_op op;
+	u16 timing_reg;
+	u16 high_speed_reg;
+	const struct mtk_i2c_compatible *dev_comp;
+};
+
+static const struct i2c_adapter_quirks mt6577_i2c_quirks = {
+	.flags = I2C_AQ_COMB_WRITE_THEN_READ,
+	.max_num_msgs = 1,
+	.max_write_len = 255,
+	.max_read_len = 255,
+	.max_comb_1st_msg_len = 255,
+	.max_comb_2nd_msg_len = 31,
+};
+
+static const struct i2c_adapter_quirks mt8173_i2c_quirks = {
+	.max_num_msgs = 65535,
+	.max_write_len = 65535,
+	.max_read_len = 65535,
+	.max_comb_1st_msg_len = 65535,
+	.max_comb_2nd_msg_len = 65535,
+};
+
+static const struct mtk_i2c_compatible mt6577_compat = {
+	.quirks = &mt6577_i2c_quirks,
+	.pmic_i2c = 0,
+	.dcm = 1,
+	.auto_restart = 0,
+};
+
+static const struct mtk_i2c_compatible mt6589_compat = {
+	.quirks = &mt6577_i2c_quirks,
+	.pmic_i2c = 1,
+	.dcm = 0,
+	.auto_restart = 0,
+};
+
+static const struct mtk_i2c_compatible mt8173_compat = {
+	.quirks = &mt8173_i2c_quirks,
+	.pmic_i2c = 0,
+	.dcm = 1,
+	.auto_restart = 1,
+};
+
+static const struct of_device_id mtk_i2c_of_match[] = {
+	{ .compatible = "mediatek,mt6577-i2c", .data = &mt6577_compat },
+	{ .compatible = "mediatek,mt6589-i2c", .data = &mt6589_compat },
+	{ .compatible = "mediatek,mt8173-i2c", .data = &mt8173_compat },
+	{}
+};
+MODULE_DEVICE_TABLE(of, mtk_i2c_of_match);
+
+static int mtk_i2c_clock_enable(struct mtk_i2c *i2c)
+{
+	int ret;
+
+	ret = clk_prepare_enable(i2c->clk_dma);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(i2c->clk_main);
+	if (ret)
+		goto err_main;
+
+	if (i2c->have_pmic) {
+		ret = clk_prepare_enable(i2c->clk_pmic);
+		if (ret)
+			goto err_pmic;
+	}
+	return 0;
+
+err_pmic:
+	clk_disable_unprepare(i2c->clk_main);
+err_main:
+	clk_disable_unprepare(i2c->clk_dma);
+
+	return ret;
+}
+
+static void mtk_i2c_clock_disable(struct mtk_i2c *i2c)
+{
+	if (i2c->have_pmic)
+		clk_disable_unprepare(i2c->clk_pmic);
+
+	clk_disable_unprepare(i2c->clk_main);
+	clk_disable_unprepare(i2c->clk_dma);
+}
+
+static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
+{
+	u16 control_reg;
+
+	writew(I2C_SOFT_RST, i2c->base + OFFSET_SOFTRESET);
+
+	/* Set ioconfig */
+	if (i2c->use_push_pull)
+		writew(I2C_IO_CONFIG_PUSH_PULL, i2c->base + OFFSET_IO_CONFIG);
+	else
+		writew(I2C_IO_CONFIG_OPEN_DRAIN, i2c->base + OFFSET_IO_CONFIG);
+
+	if (i2c->dev_comp->dcm)
+		writew(I2C_DCM_DISABLE, i2c->base + OFFSET_DCM_EN);
+
+	writew(i2c->timing_reg, i2c->base + OFFSET_TIMING);
+	writew(i2c->high_speed_reg, i2c->base + OFFSET_HS);
+
+	/* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */
+	if (i2c->have_pmic)
+		writew(I2C_CONTROL_WRAPPER, i2c->base + OFFSET_PATH_DIR);
+
+	control_reg = I2C_CONTROL_ACKERR_DET_EN |
+		      I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
+	writew(control_reg, i2c->base + OFFSET_CONTROL);
+	writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN);
+}
+
+/*
+ * Calculate i2c port speed
+ *
+ * Hardware design:
+ * i2c_bus_freq = parent_clk / (clock_div * 2 * sample_cnt * step_cnt)
+ * clock_div: fixed in hardware, but may be various in different SoCs
+ *
+ * The calculation want to pick the highest bus frequency that is still
+ * less than or equal to i2c->speed_hz. The calculation try to get
+ * sample_cnt and step_cn
+ */
+static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk,
+			     unsigned int clock_div)
+{
+	unsigned int clk_src;
+	unsigned int step_cnt;
+	unsigned int sample_cnt;
+	unsigned int max_step_cnt;
+	unsigned int target_speed;
+	unsigned int base_sample_cnt = MAX_SAMPLE_CNT_DIV;
+	unsigned int base_step_cnt;
+	unsigned int opt_div;
+	unsigned int best_mul;
+	unsigned int cnt_mul;
+
+	clk_src = parent_clk / clock_div;
+	target_speed = i2c->speed_hz;
+
+	if (target_speed > MAX_HS_MODE_SPEED)
+		target_speed = MAX_HS_MODE_SPEED;
+
+	if (target_speed > MAX_FS_MODE_SPEED)
+		max_step_cnt = MAX_HS_STEP_CNT_DIV;
+	else
+		max_step_cnt = MAX_STEP_CNT_DIV;
+
+	base_step_cnt = max_step_cnt;
+	/* Find the best combination */
+	opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed);
+	best_mul = MAX_SAMPLE_CNT_DIV * max_step_cnt;
+
+	/* Search for the best pair (sample_cnt, step_cnt) with
+	 * 0 < sample_cnt < MAX_SAMPLE_CNT_DIV
+	 * 0 < step_cnt < max_step_cnt
+	 * sample_cnt * step_cnt >= opt_div
+	 * optimizing for sample_cnt * step_cnt being minimal
+	 */
+	for (sample_cnt = 1; sample_cnt <= MAX_SAMPLE_CNT_DIV; sample_cnt++) {
+		step_cnt = DIV_ROUND_UP(opt_div, sample_cnt);
+		cnt_mul = step_cnt * sample_cnt;
+		if (step_cnt > max_step_cnt)
+			continue;
+
+		if (cnt_mul < best_mul) {
+			best_mul = cnt_mul;
+			base_sample_cnt = sample_cnt;
+			base_step_cnt = step_cnt;
+			if (best_mul == opt_div)
+				break;
+		}
+	}
+
+	sample_cnt = base_sample_cnt;
+	step_cnt = base_step_cnt;
+
+	if ((clk_src / (2 * sample_cnt * step_cnt)) > target_speed) {
+		/* In this case, hardware can't support such
+		 * low i2c_bus_freq
+		 */
+		dev_dbg(i2c->dev, "Unsupported speed (%uhz)\n",	target_speed);
+		return -EINVAL;
+	}
+
+	step_cnt--;
+	sample_cnt--;
+
+	if (target_speed > MAX_FS_MODE_SPEED) {
+		/* Set the high speed mode register */
+		i2c->timing_reg = I2C_FS_TIME_INIT_VALUE;
+		i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE |
+			(sample_cnt << 12) | (step_cnt << 8);
+	} else {
+		i2c->timing_reg = (sample_cnt << 8) | (step_cnt << 0);
+		/* Disable the high speed transaction */
+		i2c->high_speed_reg = I2C_TIME_CLR_VALUE;
+	}
+
+	return 0;
+}
+
+static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
+			       int num, int left_num)
+{
+	u16 addr_reg;
+	u16 start_reg;
+	u16 control_reg;
+	u16 restart_flag = 0;
+	dma_addr_t rpaddr = 0;
+	dma_addr_t wpaddr = 0;
+	int ret;
+
+	i2c->irq_stat = 0;
+
+	if (i2c->dev_comp->auto_restart)
+		restart_flag = I2C_RS_TRANSFER;
+
+	reinit_completion(&i2c->msg_complete);
+
+	control_reg = readw(i2c->base + OFFSET_CONTROL) &
+			~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS);
+	if ((i2c->speed_hz > 400000) || (left_num >= 1))
+		control_reg |= I2C_CONTROL_RS;
+
+	if (i2c->op == I2C_MASTER_WRRD)
+		control_reg |= I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS;
+
+	writew(control_reg, i2c->base + OFFSET_CONTROL);
+
+	/* set start condition */
+	if (i2c->speed_hz <= 100000)
+		writew(I2C_ST_START_CON, i2c->base + OFFSET_EXT_CONF);
+	else
+		writew(I2C_FS_START_CON, i2c->base + OFFSET_EXT_CONF);
+
+	addr_reg = msgs->addr << 1;
+	if (i2c->op == I2C_MASTER_RD)
+		addr_reg |= 0x1;
+
+	writew(addr_reg, i2c->base + OFFSET_SLAVE_ADDR);
+
+	/* Clear interrupt status */
+	writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
+	       I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT);
+	writew(I2C_FIFO_ADDR_CLR, i2c->base + OFFSET_FIFO_ADDR_CLR);
+
+	/* Enable interrupt */
+	writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
+	       I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_MASK);
+
+	/* Set transfer and transaction len */
+	if (i2c->op == I2C_MASTER_WRRD) {
+		writew(msgs->len | ((msgs + 1)->len) << 8,
+		       i2c->base + OFFSET_TRANSFER_LEN);
+		writew(I2C_WRRD_TRANAC_VALUE, i2c->base + OFFSET_TRANSAC_LEN);
+	} else {
+		writew(msgs->len, i2c->base + OFFSET_TRANSFER_LEN);
+		writew(num, i2c->base + OFFSET_TRANSAC_LEN);
+	}
+
+	/* Prepare buffer data to start transfer */
+	if (i2c->op == I2C_MASTER_RD) {
+		writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
+		writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON);
+		rpaddr = dma_map_single(i2c->dev, msgs->buf,
+					msgs->len, DMA_FROM_DEVICE);
+		if (dma_mapping_error(i2c->dev, rpaddr))
+			return -ENOMEM;
+		writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
+		writel(msgs->len, i2c->pdmabase + OFFSET_RX_LEN);
+	} else if (i2c->op == I2C_MASTER_WR) {
+		writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
+		writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON);
+		wpaddr = dma_map_single(i2c->dev, msgs->buf,
+					msgs->len, DMA_TO_DEVICE);
+		if (dma_mapping_error(i2c->dev, wpaddr))
+			return -ENOMEM;
+		writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
+		writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
+	} else {
+		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG);
+		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON);
+		wpaddr = dma_map_single(i2c->dev, msgs->buf,
+					msgs->len, DMA_TO_DEVICE);
+		if (dma_mapping_error(i2c->dev, wpaddr))
+			return -ENOMEM;
+		rpaddr = dma_map_single(i2c->dev, (msgs + 1)->buf,
+					(msgs + 1)->len,
+					DMA_FROM_DEVICE);
+		if (dma_mapping_error(i2c->dev, rpaddr)) {
+			dma_unmap_single(i2c->dev, wpaddr,
+					 msgs->len, DMA_TO_DEVICE);
+			return -ENOMEM;
+		}
+		writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
+		writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
+		writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
+		writel((msgs + 1)->len, i2c->pdmabase + OFFSET_RX_LEN);
+	}
+
+	writel(I2C_DMA_START_EN, i2c->pdmabase + OFFSET_EN);
+
+	if (!i2c->dev_comp->auto_restart) {
+		start_reg = I2C_TRANSAC_START;
+	} else {
+		start_reg = I2C_TRANSAC_START | I2C_RS_MUL_TRIG;
+		if (left_num >= 1)
+			start_reg |= I2C_RS_MUL_CNFG;
+	}
+	writew(start_reg, i2c->base + OFFSET_START);
+
+	ret = wait_for_completion_timeout(&i2c->msg_complete,
+					  i2c->adap.timeout);
+
+	/* Clear interrupt mask */
+	writew(~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
+	       I2C_TRANSAC_COMP), i2c->base + OFFSET_INTR_MASK);
+
+	if (i2c->op == I2C_MASTER_WR) {
+		dma_unmap_single(i2c->dev, wpaddr,
+				 msgs->len, DMA_TO_DEVICE);
+	} else if (i2c->op == I2C_MASTER_RD) {
+		dma_unmap_single(i2c->dev, rpaddr,
+				 msgs->len, DMA_FROM_DEVICE);
+	} else {
+		dma_unmap_single(i2c->dev, wpaddr, msgs->len,
+				 DMA_TO_DEVICE);
+		dma_unmap_single(i2c->dev, rpaddr, (msgs + 1)->len,
+				 DMA_FROM_DEVICE);
+	}
+
+	if (ret == 0) {
+		dev_dbg(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr);
+		mtk_i2c_init_hw(i2c);
+		return -ETIMEDOUT;
+	}
+
+	completion_done(&i2c->msg_complete);
+
+	if (i2c->irq_stat & (I2C_HS_NACKERR | I2C_ACKERR)) {
+		dev_dbg(i2c->dev, "addr: %x, transfer ACK error\n", msgs->addr);
+		mtk_i2c_init_hw(i2c);
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+static int mtk_i2c_transfer(struct i2c_adapter *adap,
+			    struct i2c_msg msgs[], int num)
+{
+	int ret;
+	int left_num = num;
+	struct mtk_i2c *i2c = i2c_get_adapdata(adap);
+
+	ret = mtk_i2c_clock_enable(i2c);
+	if (ret)
+		return ret;
+
+	while (left_num--) {
+		if (!msgs->buf) {
+			dev_dbg(i2c->dev, "data buffer is NULL.\n");
+			ret = -EINVAL;
+			goto err_exit;
+		}
+
+		if (msgs->flags & I2C_M_RD)
+			i2c->op = I2C_MASTER_RD;
+		else
+			i2c->op = I2C_MASTER_WR;
+
+		if (!i2c->dev_comp->auto_restart) {
+			if (num > 1) {
+				/* combined two messages into one transaction */
+				i2c->op = I2C_MASTER_WRRD;
+				left_num--;
+			}
+		}
+
+		/* always use DMA mode. */
+		ret = mtk_i2c_do_transfer(i2c, msgs, num, left_num);
+		if (ret < 0)
+			goto err_exit;
+
+		msgs++;
+	}
+	/* the return value is number of executed messages */
+	ret = num;
+
+err_exit:
+	mtk_i2c_clock_disable(i2c);
+	return ret;
+}
+
+static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
+{
+	struct mtk_i2c *i2c = dev_id;
+	u16 restart_flag = 0;
+
+	if (i2c->dev_comp->auto_restart)
+		restart_flag = I2C_RS_TRANSFER;
+
+	i2c->irq_stat = readw(i2c->base + OFFSET_INTR_STAT);
+	writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR
+		| I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT);
+
+	complete(&i2c->msg_complete);
+
+	return IRQ_HANDLED;
+}
+
+static u32 mtk_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm mtk_i2c_algorithm = {
+	.master_xfer = mtk_i2c_transfer,
+	.functionality = mtk_i2c_functionality,
+};
+
+static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c,
+			    unsigned int *clk_src_div)
+{
+	int ret;
+
+	ret = of_property_read_u32(np, "clock-frequency", &i2c->speed_hz);
+	if (ret < 0)
+		i2c->speed_hz = I2C_DEFAULT_SPEED;
+
+	ret = of_property_read_u32(np, "clock-div", clk_src_div);
+	if (ret < 0)
+		return ret;
+
+	if (*clk_src_div == 0)
+		return -EINVAL;
+
+	i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic");
+	i2c->use_push_pull =
+		of_property_read_bool(np, "mediatek,use-push-pull");
+
+	return 0;
+}
+
+static int mtk_i2c_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *of_id;
+	int ret = 0;
+	struct mtk_i2c *i2c;
+	struct clk *clk;
+	unsigned int clk_src_div;
+	struct resource *res;
+	int irq;
+
+	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
+	if (!i2c)
+		return -ENOMEM;
+
+	ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c, &clk_src_div);
+	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))
+		return PTR_ERR(i2c->base);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	i2c->pdmabase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(i2c->pdmabase))
+		return PTR_ERR(i2c->pdmabase);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0)
+		return irq;
+
+	init_completion(&i2c->msg_complete);
+
+	of_id = of_match_node(mtk_i2c_of_match, pdev->dev.of_node);
+	if (!of_id)
+		return -EINVAL;
+
+	i2c->dev_comp = of_id->data;
+	i2c->adap.dev.of_node = pdev->dev.of_node;
+	i2c->dev = &pdev->dev;
+	i2c->adap.dev.parent = &pdev->dev;
+	i2c->adap.owner = THIS_MODULE;
+	i2c->adap.algo = &mtk_i2c_algorithm;
+	i2c->adap.quirks = i2c->dev_comp->quirks;
+	i2c->adap.timeout = 2 * HZ;
+	i2c->adap.retries = 1;
+
+	if (i2c->have_pmic && !i2c->dev_comp->pmic_i2c)
+		return -EINVAL;
+
+	i2c->clk_main = devm_clk_get(&pdev->dev, "main");
+	if (IS_ERR(i2c->clk_main)) {
+		dev_err(&pdev->dev, "cannot get main clock\n");
+		return PTR_ERR(i2c->clk_main);
+	}
+
+	i2c->clk_dma = devm_clk_get(&pdev->dev, "dma");
+	if (IS_ERR(i2c->clk_dma)) {
+		dev_err(&pdev->dev, "cannot get dma clock\n");
+		return PTR_ERR(i2c->clk_dma);
+	}
+
+	clk = i2c->clk_main;
+	if (i2c->have_pmic) {
+		i2c->clk_pmic = devm_clk_get(&pdev->dev, "pmic");
+		if (IS_ERR(i2c->clk_pmic)) {
+			dev_err(&pdev->dev, "cannot get pmic clock\n");
+			return PTR_ERR(i2c->clk_pmic);
+		}
+		clk = i2c->clk_pmic;
+	}
+
+	strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name));
+
+	ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk), clk_src_div);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to set the speed.\n");
+		return -EINVAL;
+	}
+
+	ret = mtk_i2c_clock_enable(i2c);
+	if (ret) {
+		dev_err(&pdev->dev, "clock enable failed!\n");
+		return ret;
+	}
+	mtk_i2c_init_hw(i2c);
+	mtk_i2c_clock_disable(i2c);
+
+	ret = devm_request_irq(&pdev->dev, irq, mtk_i2c_irq,
+			       IRQF_TRIGGER_NONE, I2C_DRV_NAME, i2c);
+	if (ret < 0) {
+		dev_err(&pdev->dev,
+			"Request I2C IRQ %d fail\n", irq);
+		return ret;
+	}
+
+	i2c_set_adapdata(&i2c->adap, i2c);
+	ret = i2c_add_adapter(&i2c->adap);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add i2c bus to i2c core\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, i2c);
+
+	return 0;
+}
+
+static int mtk_i2c_remove(struct platform_device *pdev)
+{
+	struct mtk_i2c *i2c = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&i2c->adap);
+
+	return 0;
+}
+
+static struct platform_driver mtk_i2c_driver = {
+	.probe = mtk_i2c_probe,
+	.remove = mtk_i2c_remove,
+	.driver = {
+		.name = I2C_DRV_NAME,
+		.of_match_table = of_match_ptr(mtk_i2c_of_match),
+	},
+};
+
+module_platform_driver(mtk_i2c_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MediaTek I2C Bus Driver");
+MODULE_AUTHOR("Xudong Chen <xudong.chen@mediatek.com>");

drivers/i2c/busses/i2c-mxs.c

@@ -784,7 +784,7 @@ static int mxs_i2c_get_ofdata(struct mxs_i2c_dev *i2c)
 	return 0;
 }
 
-static struct platform_device_id mxs_i2c_devtype[] = {
+static const struct platform_device_id mxs_i2c_devtype[] = {
 	{
 		.name = "imx23-i2c",
 		.driver_data = MXS_I2C_V1,

drivers/i2c/busses/i2c-octeon.c

@@ -200,7 +200,7 @@ static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
  */
 static int octeon_i2c_wait(struct octeon_i2c *i2c)
 {
-	int result;
+	long result;
 
 	octeon_i2c_int_enable(i2c);
 
@@ -210,10 +210,7 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c)
 
 	octeon_i2c_int_disable(i2c);
 
-	if (result < 0) {
-		dev_dbg(i2c->dev, "%s: wait interrupted\n", __func__);
-		return result;
-	} else if (result == 0) {
+	if (result == 0) {
 		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
 		return -ETIMEDOUT;
 	}

drivers/i2c/busses/i2c-omap.c

@@ -38,6 +38,7 @@
 #include <linux/slab.h>
 #include <linux/i2c-omap.h>
 #include <linux/pm_runtime.h>
+#include <linux/pinctrl/consumer.h>
 
 /* I2C controller revisions */
 #define OMAP_I2C_OMAP1_REV_2		0x20
@@ -481,10 +482,8 @@ static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
 
 	timeout = jiffies + OMAP_I2C_TIMEOUT;
 	while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
-		if (time_after(jiffies, timeout)) {
-			dev_warn(dev->dev, "timeout waiting for bus ready\n");
-			return -ETIMEDOUT;
-		}
+		if (time_after(jiffies, timeout))
+			return i2c_recover_bus(&dev->adapter);
 		msleep(1);
 	}
 
@@ -1209,6 +1208,68 @@ MODULE_DEVICE_TABLE(of, omap_i2c_of_match);
 #define OMAP_I2C_SCHEME_0		0
 #define OMAP_I2C_SCHEME_1		1
 
+static int omap_i2c_get_scl(struct i2c_adapter *adap)
+{
+	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+
+	return reg & OMAP_I2C_SYSTEST_SCL_I_FUNC;
+}
+
+static int omap_i2c_get_sda(struct i2c_adapter *adap)
+{
+	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+
+	return reg & OMAP_I2C_SYSTEST_SDA_I_FUNC;
+}
+
+static void omap_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+	if (val)
+		reg |= OMAP_I2C_SYSTEST_SCL_O;
+	else
+		reg &= ~OMAP_I2C_SYSTEST_SCL_O;
+	omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static void omap_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+	reg |= OMAP_I2C_SYSTEST_ST_EN;
+	omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static void omap_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+	reg &= ~OMAP_I2C_SYSTEST_ST_EN;
+	omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static struct i2c_bus_recovery_info omap_i2c_bus_recovery_info = {
+	.get_scl		= omap_i2c_get_scl,
+	.get_sda		= omap_i2c_get_sda,
+	.set_scl		= omap_i2c_set_scl,
+	.prepare_recovery	= omap_i2c_prepare_recovery,
+	.unprepare_recovery	= omap_i2c_unprepare_recovery,
+	.recover_bus		= i2c_generic_scl_recovery,
+};
+
 static int
 omap_i2c_probe(struct platform_device *pdev)
 {
@@ -1358,6 +1419,7 @@ omap_i2c_probe(struct platform_device *pdev)
 	adap->algo = &omap_i2c_algo;
 	adap->dev.parent = &pdev->dev;
 	adap->dev.of_node = pdev->dev.of_node;
+	adap->bus_recovery_info = &omap_i2c_bus_recovery_info;
 
 	/* i2c device drivers may be active on return from add_adapter() */
 	adap->nr = pdev->id;
@@ -1423,6 +1485,8 @@ static int omap_i2c_runtime_suspend(struct device *dev)
 		omap_i2c_read_reg(_dev, OMAP_I2C_STAT_REG);
 	}
 
+	pinctrl_pm_select_sleep_state(dev);
+
 	return 0;
 }
 
@@ -1431,6 +1495,8 @@ static int omap_i2c_runtime_resume(struct device *dev)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
 
+	pinctrl_pm_select_default_state(dev);
+
 	if (!_dev->regs)
 		return 0;
 

drivers/i2c/busses/i2c-rcar.c

@@ -490,7 +490,8 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 	struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
 	struct device *dev = rcar_i2c_priv_to_dev(priv);
 	unsigned long flags;
-	int i, ret, timeout;
+	int i, ret;
+	long timeout;
 
 	pm_runtime_get_sync(dev);
 
@@ -532,7 +533,7 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 
 		timeout = wait_event_timeout(priv->wait,
 					     rcar_i2c_flags_has(priv, ID_DONE),
-					     5 * HZ);
+					     adap->timeout);
 		if (!timeout) {
 			ret = -ETIMEDOUT;
 			break;
@@ -604,7 +605,8 @@ static int rcar_unreg_slave(struct i2c_client *slave)
 static u32 rcar_i2c_func(struct i2c_adapter *adap)
 {
 	/* This HW can't do SMBUS_QUICK and NOSTART */
-	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+	return I2C_FUNC_I2C | I2C_FUNC_SLAVE |
+		(I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
 }
 
 static const struct i2c_algorithm rcar_i2c_algo = {
@@ -713,7 +715,7 @@ static int rcar_i2c_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static struct platform_device_id rcar_i2c_id_table[] = {
+static const struct platform_device_id rcar_i2c_id_table[] = {
 	{ "i2c-rcar",		I2C_RCAR_GEN1 },
 	{ "i2c-rcar_gen1",	I2C_RCAR_GEN1 },
 	{ "i2c-rcar_gen2",	I2C_RCAR_GEN2 },

drivers/i2c/busses/i2c-rk3x.c

@@ -72,7 +72,7 @@ enum {
 #define REG_INT_ALL       0x7f
 
 /* Constants */
-#define WAIT_TIMEOUT      200 /* ms */
+#define WAIT_TIMEOUT      1000 /* ms */
 #define DEFAULT_SCL_RATE  (100 * 1000) /* Hz */
 
 enum rk3x_i2c_state {

drivers/i2c/busses/i2c-s3c2410.c

@@ -132,7 +132,7 @@ struct s3c24xx_i2c {
 	unsigned int		sys_i2c_cfg;
 };
 
-static struct platform_device_id s3c24xx_driver_ids[] = {
+static const struct platform_device_id s3c24xx_driver_ids[] = {
 	{
 		.name		= "s3c2410-i2c",
 		.driver_data	= 0,

drivers/i2c/busses/i2c-sh_mobile.c

@@ -150,6 +150,7 @@ struct sh_mobile_i2c_data {
 
 struct sh_mobile_dt_config {
 	int clks_per_count;
+	void (*setup)(struct sh_mobile_i2c_data *pd);
 };
 
 #define IIC_FLAG_HAS_ICIC67	(1 << 0)
@@ -164,6 +165,7 @@ struct sh_mobile_dt_config {
 #define ICIC			0x0c
 #define ICCL			0x10
 #define ICCH			0x14
+#define ICSTART			0x70
 
 /* Register bits */
 #define ICCR_ICE		0x80
@@ -190,6 +192,8 @@ struct sh_mobile_dt_config {
 #define ICIC_WAITE		0x02
 #define ICIC_DTEE		0x01
 
+#define ICSTART_ICSTART		0x10
+
 static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data)
 {
 	if (offs == ICIC)
@@ -726,7 +730,8 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
 	struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
 	struct i2c_msg	*msg;
 	int err = 0;
-	int i, k;
+	int i;
+	long timeout;
 
 	activate_ch(pd);
 
@@ -745,10 +750,10 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
 			i2c_op(pd, OP_START, 0);
 
 		/* The interrupt handler takes care of the rest... */
-		k = wait_event_timeout(pd->wait,
+		timeout = wait_event_timeout(pd->wait,
 				       pd->sr & (ICSR_TACK | SW_DONE),
-				       5 * HZ);
-		if (!k) {
+				       adapter->timeout);
+		if (!timeout) {
 			dev_err(pd->dev, "Transfer request timed out\n");
 			if (pd->dma_direction != DMA_NONE)
 				sh_mobile_i2c_cleanup_dma(pd);
@@ -782,6 +787,33 @@ static struct i2c_algorithm sh_mobile_i2c_algorithm = {
 	.master_xfer	= sh_mobile_i2c_xfer,
 };
 
+/*
+ * 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)
+{
+	iic_set_clr(pd, ICCR, ICCR_ICE, 0);
+	iic_rd(pd, ICCR); /* dummy read */
+
+	iic_set_clr(pd, ICSTART, ICSTART_ICSTART, 0);
+	iic_rd(pd, ICSTART); /* dummy read */
+
+	udelay(10);
+
+	iic_wr(pd, ICCR, ICCR_SCP);
+	iic_wr(pd, ICSTART, 0);
+
+	udelay(10);
+
+	iic_wr(pd, ICCR, ICCR_TRS);
+	udelay(10);
+	iic_wr(pd, ICCR, 0);
+	udelay(10);
+	iic_wr(pd, ICCR, ICCR_TRS);
+	udelay(10);
+}
+
 static const struct sh_mobile_dt_config default_dt_config = {
 	.clks_per_count = 1,
 };
@@ -790,9 +822,15 @@ static const struct sh_mobile_dt_config fast_clock_dt_config = {
 	.clks_per_count = 2,
 };
 
+static const struct sh_mobile_dt_config r8a7740_dt_config = {
+	.clks_per_count = 1,
+	.setup = sh_mobile_i2c_r8a7740_workaround,
+};
+
 static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
 	{ .compatible = "renesas,rmobile-iic", .data = &default_dt_config },
 	{ .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-r8a7791", .data = &fast_clock_dt_config },
 	{ .compatible = "renesas,iic-r8a7792", .data = &fast_clock_dt_config },
@@ -885,6 +923,9 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
 
 			config = match->data;
 			pd->clks_per_count = config->clks_per_count;
+
+			if (config->setup)
+				config->setup(pd);
 		}
 	} else {
 		if (pdata && pdata->bus_speed)

drivers/i2c/busses/i2c-tegra.c

@@ -656,8 +656,8 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
 static u32 tegra_i2c_func(struct i2c_adapter *adap)
 {
 	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
-	u32 ret = I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
-				I2C_FUNC_PROTOCOL_MANGLING;
+	u32 ret = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
+		  I2C_FUNC_10BIT_ADDR |	I2C_FUNC_PROTOCOL_MANGLING;
 
 	if (i2c_dev->hw->has_continue_xfer_support)
 		ret |= I2C_FUNC_NOSTART;
@@ -669,6 +669,12 @@ static const struct i2c_algorithm tegra_i2c_algo = {
 	.functionality	= tegra_i2c_func,
 };
 
+/* payload size is only 12 bit */
+static struct i2c_adapter_quirks tegra_i2c_quirks = {
+	.max_read_len = 4096,
+	.max_write_len = 4096,
+};
+
 static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
 	.has_continue_xfer_support = false,
 	.has_per_pkt_xfer_complete_irq = false,
@@ -739,6 +745,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
 	i2c_dev->base = base;
 	i2c_dev->div_clk = div_clk;
 	i2c_dev->adapter.algo = &tegra_i2c_algo;
+	i2c_dev->adapter.quirks = &tegra_i2c_quirks;
 	i2c_dev->irq = irq;
 	i2c_dev->cont_id = pdev->id;
 	i2c_dev->dev = &pdev->dev;

drivers/i2c/busses/i2c-xgene-slimpro.c

+/*
+ * X-Gene SLIMpro I2C Driver
+ *
+ * Copyright (c) 2014, Applied Micro Circuits Corporation
+ * Author: Feng Kan <fkan@apm.com>
+ * Author: Hieu Le <hnle@apm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * This driver provides support for X-Gene SLIMpro I2C device access
+ * using the APM X-Gene SLIMpro mailbox driver.
+ *
+ */
+#include <linux/acpi.h>
+#include <linux/dma-mapping.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/version.h>
+
+#define MAILBOX_OP_TIMEOUT		1000	/* Operation time out in ms */
+#define MAILBOX_I2C_INDEX		0
+#define SLIMPRO_IIC_BUS			1	/* Use I2C bus 1 only */
+
+#define SMBUS_CMD_LEN			1
+#define BYTE_DATA			1
+#define WORD_DATA			2
+#define BLOCK_DATA			3
+
+#define SLIMPRO_IIC_I2C_PROTOCOL	0
+#define SLIMPRO_IIC_SMB_PROTOCOL	1
+
+#define SLIMPRO_IIC_READ		0
+#define SLIMPRO_IIC_WRITE		1
+
+#define IIC_SMB_WITHOUT_DATA_LEN	0
+#define IIC_SMB_WITH_DATA_LEN		1
+
+#define SLIMPRO_DEBUG_MSG		0
+#define SLIMPRO_MSG_TYPE_SHIFT		28
+#define SLIMPRO_DBG_SUBTYPE_I2C1READ	4
+#define SLIMPRO_DBGMSG_TYPE_SHIFT	24
+#define SLIMPRO_DBGMSG_TYPE_MASK	0x0F000000U
+#define SLIMPRO_IIC_DEV_SHIFT		23
+#define SLIMPRO_IIC_DEV_MASK		0x00800000U
+#define SLIMPRO_IIC_DEVID_SHIFT		13
+#define SLIMPRO_IIC_DEVID_MASK		0x007FE000U
+#define SLIMPRO_IIC_RW_SHIFT		12
+#define SLIMPRO_IIC_RW_MASK		0x00001000U
+#define SLIMPRO_IIC_PROTO_SHIFT		11
+#define SLIMPRO_IIC_PROTO_MASK		0x00000800U
+#define SLIMPRO_IIC_ADDRLEN_SHIFT	8
+#define SLIMPRO_IIC_ADDRLEN_MASK	0x00000700U
+#define SLIMPRO_IIC_DATALEN_SHIFT	0
+#define SLIMPRO_IIC_DATALEN_MASK	0x000000FFU
+
+/*
+ * SLIMpro I2C message encode
+ *
+ * dev		- Controller number (0-based)
+ * chip		- I2C chip address
+ * op		- SLIMPRO_IIC_READ or SLIMPRO_IIC_WRITE
+ * proto	- SLIMPRO_IIC_SMB_PROTOCOL or SLIMPRO_IIC_I2C_PROTOCOL
+ * addrlen	- Length of the address field
+ * datalen	- Length of the data field
+ */
+#define SLIMPRO_IIC_ENCODE_MSG(dev, chip, op, proto, addrlen, datalen) \
+	((SLIMPRO_DEBUG_MSG << SLIMPRO_MSG_TYPE_SHIFT) | \
+	((SLIMPRO_DBG_SUBTYPE_I2C1READ << SLIMPRO_DBGMSG_TYPE_SHIFT) & \
+	SLIMPRO_DBGMSG_TYPE_MASK) | \
+	((dev << SLIMPRO_IIC_DEV_SHIFT) & SLIMPRO_IIC_DEV_MASK) | \
+	((chip << SLIMPRO_IIC_DEVID_SHIFT) & SLIMPRO_IIC_DEVID_MASK) | \
+	((op << SLIMPRO_IIC_RW_SHIFT) & SLIMPRO_IIC_RW_MASK) | \
+	((proto << SLIMPRO_IIC_PROTO_SHIFT) & SLIMPRO_IIC_PROTO_MASK) | \
+	((addrlen << SLIMPRO_IIC_ADDRLEN_SHIFT) & SLIMPRO_IIC_ADDRLEN_MASK) | \
+	((datalen << SLIMPRO_IIC_DATALEN_SHIFT) & SLIMPRO_IIC_DATALEN_MASK))
+
+/*
+ * Encode for upper address for block data
+ */
+#define SLIMPRO_IIC_ENCODE_FLAG_BUFADDR			0x80000000
+#define SLIMPRO_IIC_ENCODE_FLAG_WITH_DATA_LEN(a)	((u32) (((a) << 30) \
+								& 0x40000000))
+#define SLIMPRO_IIC_ENCODE_UPPER_BUFADDR(a)		((u32) (((a) >> 12) \
+								& 0x3FF00000))
+#define SLIMPRO_IIC_ENCODE_ADDR(a)			((a) & 0x000FFFFF)
+
+struct slimpro_i2c_dev {
+	struct i2c_adapter adapter;
+	struct device *dev;
+	struct mbox_chan *mbox_chan;
+	struct mbox_client mbox_client;
+	struct completion rd_complete;
+	u8 dma_buffer[I2C_SMBUS_BLOCK_MAX];
+	u32 *resp_msg;
+};
+
+#define to_slimpro_i2c_dev(cl)	\
+		container_of(cl, struct slimpro_i2c_dev, mbox_client)
+
+static void slimpro_i2c_rx_cb(struct mbox_client *cl, void *mssg)
+{
+	struct slimpro_i2c_dev *ctx = to_slimpro_i2c_dev(cl);
+
+	/*
+	 * Response message format:
+	 * mssg[0] is the return code of the operation
+	 * mssg[1] is the first data word
+	 * mssg[2] is NOT used
+	 */
+	if (ctx->resp_msg)
+		*ctx->resp_msg = ((u32 *)mssg)[1];
+
+	if (ctx->mbox_client.tx_block)
+		complete(&ctx->rd_complete);
+}
+
+static int start_i2c_msg_xfer(struct slimpro_i2c_dev *ctx)
+{
+	if (ctx->mbox_client.tx_block) {
+		if (!wait_for_completion_timeout(&ctx->rd_complete,
+						 msecs_to_jiffies(MAILBOX_OP_TIMEOUT)))
+			return -ETIMEDOUT;
+	}
+
+	/* Check of invalid data or no device */
+	if (*ctx->resp_msg == 0xffffffff)
+		return -ENODEV;
+
+	return 0;
+}
+
+static int slimpro_i2c_rd(struct slimpro_i2c_dev *ctx, u32 chip,
+			  u32 addr, u32 addrlen, u32 protocol,
+			  u32 readlen, u32 *data)
+{
+	u32 msg[3];
+	int rc;
+
+	msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip,
+					SLIMPRO_IIC_READ, protocol, addrlen, readlen);
+	msg[1] = SLIMPRO_IIC_ENCODE_ADDR(addr);
+	msg[2] = 0;
+	ctx->resp_msg = data;
+	rc = mbox_send_message(ctx->mbox_chan, &msg);
+	if (rc < 0)
+		goto err;
+
+	rc = start_i2c_msg_xfer(ctx);
+err:
+	ctx->resp_msg = NULL;
+	return rc;
+}
+
+static int slimpro_i2c_wr(struct slimpro_i2c_dev *ctx, u32 chip,
+			  u32 addr, u32 addrlen, u32 protocol, u32 writelen,
+			  u32 data)
+{
+	u32 msg[3];
+	int rc;
+
+	msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip,
+					SLIMPRO_IIC_WRITE, protocol, addrlen, writelen);
+	msg[1] = SLIMPRO_IIC_ENCODE_ADDR(addr);
+	msg[2] = data;
+	ctx->resp_msg = msg;
+
+	rc = mbox_send_message(ctx->mbox_chan, &msg);
+	if (rc < 0)
+		goto err;
+
+	rc = start_i2c_msg_xfer(ctx);
+err:
+	ctx->resp_msg = NULL;
+	return rc;
+}
+
+static int slimpro_i2c_blkrd(struct slimpro_i2c_dev *ctx, u32 chip, u32 addr,
+			     u32 addrlen, u32 protocol, u32 readlen,
+			     u32 with_data_len, void *data)
+{
+	dma_addr_t paddr;
+	u32 msg[3];
+	int rc;
+
+	paddr = dma_map_single(ctx->dev, ctx->dma_buffer, readlen, DMA_FROM_DEVICE);
+	rc = dma_mapping_error(ctx->dev, paddr);
+	if (rc) {
+		dev_err(&ctx->adapter.dev, "Error in mapping dma buffer %p\n",
+			ctx->dma_buffer);
+		goto err;
+	}
+
+	msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip, SLIMPRO_IIC_READ,
+					protocol, addrlen, readlen);
+	msg[1] = SLIMPRO_IIC_ENCODE_FLAG_BUFADDR |
+		 SLIMPRO_IIC_ENCODE_FLAG_WITH_DATA_LEN(with_data_len) |
+		 SLIMPRO_IIC_ENCODE_UPPER_BUFADDR(paddr) |
+		 SLIMPRO_IIC_ENCODE_ADDR(addr);
+	msg[2] = (u32)paddr;
+	ctx->resp_msg = msg;
+
+	rc = mbox_send_message(ctx->mbox_chan, &msg);
+	if (rc < 0)
+		goto err_unmap;
+
+	rc = start_i2c_msg_xfer(ctx);
+
+	/* Copy to destination */
+	memcpy(data, ctx->dma_buffer, readlen);
+
+err_unmap:
+	dma_unmap_single(ctx->dev, paddr, readlen, DMA_FROM_DEVICE);
+err:
+	ctx->resp_msg = NULL;
+	return rc;
+}
+
+static int slimpro_i2c_blkwr(struct slimpro_i2c_dev *ctx, u32 chip,
+			     u32 addr, u32 addrlen, u32 protocol, u32 writelen,
+			     void *data)
+{
+	dma_addr_t paddr;
+	u32 msg[3];
+	int rc;
+
+	memcpy(ctx->dma_buffer, data, writelen);
+	paddr = dma_map_single(ctx->dev, ctx->dma_buffer, writelen,
+			       DMA_TO_DEVICE);
+	rc = dma_mapping_error(ctx->dev, paddr);
+	if (rc) {
+		dev_err(&ctx->adapter.dev, "Error in mapping dma buffer %p\n",
+			ctx->dma_buffer);
+		goto err;
+	}
+
+	msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip, SLIMPRO_IIC_WRITE,
+					protocol, addrlen, writelen);
+	msg[1] = SLIMPRO_IIC_ENCODE_FLAG_BUFADDR |
+		 SLIMPRO_IIC_ENCODE_UPPER_BUFADDR(paddr) |
+		 SLIMPRO_IIC_ENCODE_ADDR(addr);
+	msg[2] = (u32)paddr;
+	ctx->resp_msg = msg;
+
+	if (ctx->mbox_client.tx_block)
+		reinit_completion(&ctx->rd_complete);
+
+	rc = mbox_send_message(ctx->mbox_chan, &msg);
+	if (rc < 0)
+		goto err_unmap;
+
+	rc = start_i2c_msg_xfer(ctx);
+
+err_unmap:
+	dma_unmap_single(ctx->dev, paddr, writelen, DMA_TO_DEVICE);
+err:
+	ctx->resp_msg = NULL;
+	return rc;
+}
+
+static int xgene_slimpro_i2c_xfer(struct i2c_adapter *adap, u16 addr,
+				  unsigned short flags, char read_write,
+				  u8 command, int size,
+				  union i2c_smbus_data *data)
+{
+	struct slimpro_i2c_dev *ctx = i2c_get_adapdata(adap);
+	int ret = -EOPNOTSUPP;
+	u32 val;
+
+	switch (size) {
+	case I2C_SMBUS_BYTE:
+		if (read_write == I2C_SMBUS_READ) {
+			ret = slimpro_i2c_rd(ctx, addr, 0, 0,
+					     SLIMPRO_IIC_SMB_PROTOCOL,
+					     BYTE_DATA, &val);
+			data->byte = val;
+		} else {
+			ret = slimpro_i2c_wr(ctx, addr, command, SMBUS_CMD_LEN,
+					     SLIMPRO_IIC_SMB_PROTOCOL,
+					     0, 0);
+		}
+		break;
+	case I2C_SMBUS_BYTE_DATA:
+		if (read_write == I2C_SMBUS_READ) {
+			ret = slimpro_i2c_rd(ctx, addr, command, SMBUS_CMD_LEN,
+					     SLIMPRO_IIC_SMB_PROTOCOL,
+					     BYTE_DATA, &val);
+			data->byte = val;
+		} else {
+			val = data->byte;
+			ret = slimpro_i2c_wr(ctx, addr, command, SMBUS_CMD_LEN,
+					     SLIMPRO_IIC_SMB_PROTOCOL,
+					     BYTE_DATA, val);
+		}
+		break;
+	case I2C_SMBUS_WORD_DATA:
+		if (read_write == I2C_SMBUS_READ) {
+			ret = slimpro_i2c_rd(ctx, addr, command, SMBUS_CMD_LEN,
+					     SLIMPRO_IIC_SMB_PROTOCOL,
+					     WORD_DATA, &val);
+			data->word = val;
+		} else {
+			val = data->word;
+			ret = slimpro_i2c_wr(ctx, addr, command, SMBUS_CMD_LEN,
+					     SLIMPRO_IIC_SMB_PROTOCOL,
+					     WORD_DATA, val);
+		}
+		break;
+	case I2C_SMBUS_BLOCK_DATA:
+		if (read_write == I2C_SMBUS_READ) {
+			ret = slimpro_i2c_blkrd(ctx, addr, command,
+						SMBUS_CMD_LEN,
+						SLIMPRO_IIC_SMB_PROTOCOL,
+						I2C_SMBUS_BLOCK_MAX + 1,
+						IIC_SMB_WITH_DATA_LEN,
+						&data->block[0]);
+
+		} else {
+			ret = slimpro_i2c_blkwr(ctx, addr, command,
+						SMBUS_CMD_LEN,
+						SLIMPRO_IIC_SMB_PROTOCOL,
+						data->block[0] + 1,
+						&data->block[0]);
+		}
+		break;
+	case I2C_SMBUS_I2C_BLOCK_DATA:
+		if (read_write == I2C_SMBUS_READ) {
+			ret = slimpro_i2c_blkrd(ctx, addr,
+						command,
+						SMBUS_CMD_LEN,
+						SLIMPRO_IIC_I2C_PROTOCOL,
+						I2C_SMBUS_BLOCK_MAX,
+						IIC_SMB_WITHOUT_DATA_LEN,
+						&data->block[1]);
+		} else {
+			ret = slimpro_i2c_blkwr(ctx, addr, command,
+						SMBUS_CMD_LEN,
+						SLIMPRO_IIC_I2C_PROTOCOL,
+						data->block[0],
+						&data->block[1]);
+		}
+		break;
+	default:
+		break;
+	}
+	return ret;
+}
+
+/*
+* Return list of supported functionality.
+*/
+static u32 xgene_slimpro_i2c_func(struct i2c_adapter *adapter)
+{
+	return I2C_FUNC_SMBUS_BYTE |
+		I2C_FUNC_SMBUS_BYTE_DATA |
+		I2C_FUNC_SMBUS_WORD_DATA |
+		I2C_FUNC_SMBUS_BLOCK_DATA |
+		I2C_FUNC_SMBUS_I2C_BLOCK;
+}
+
+static struct i2c_algorithm xgene_slimpro_i2c_algorithm = {
+	.smbus_xfer = xgene_slimpro_i2c_xfer,
+	.functionality = xgene_slimpro_i2c_func,
+};
+
+static int xgene_slimpro_i2c_probe(struct platform_device *pdev)
+{
+	struct slimpro_i2c_dev *ctx;
+	struct i2c_adapter *adapter;
+	struct mbox_client *cl;
+	int rc;
+
+	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->dev = &pdev->dev;
+	platform_set_drvdata(pdev, ctx);
+	cl = &ctx->mbox_client;
+
+	/* Request mailbox channel */
+	cl->dev = &pdev->dev;
+	cl->rx_callback = slimpro_i2c_rx_cb;
+	cl->tx_block = true;
+	init_completion(&ctx->rd_complete);
+	cl->tx_tout = MAILBOX_OP_TIMEOUT;
+	cl->knows_txdone = false;
+	ctx->mbox_chan = mbox_request_channel(cl, MAILBOX_I2C_INDEX);
+	if (IS_ERR(ctx->mbox_chan)) {
+		dev_err(&pdev->dev, "i2c mailbox channel request failed\n");
+		return PTR_ERR(ctx->mbox_chan);
+	}
+
+	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+	if (rc)
+		dev_warn(&pdev->dev, "Unable to set dma mask\n");
+
+	/* Setup I2C adapter */
+	adapter = &ctx->adapter;
+	snprintf(adapter->name, sizeof(adapter->name), "MAILBOX I2C");
+	adapter->algo = &xgene_slimpro_i2c_algorithm;
+	adapter->class = I2C_CLASS_HWMON;
+	adapter->dev.parent = &pdev->dev;
+	i2c_set_adapdata(adapter, ctx);
+	rc = i2c_add_adapter(adapter);
+	if (rc) {
+		dev_err(&pdev->dev, "Adapter registeration failed\n");
+		return rc;
+	}
+
+	dev_info(&pdev->dev, "Mailbox I2C Adapter registered\n");
+	return 0;
+}
+
+static int xgene_slimpro_i2c_remove(struct platform_device *pdev)
+{
+	struct slimpro_i2c_dev *ctx = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&ctx->adapter);
+
+	mbox_free_channel(ctx->mbox_chan);
+
+	return 0;
+}
+
+static const struct of_device_id xgene_slimpro_i2c_dt_ids[] = {
+	{.compatible = "apm,xgene-slimpro-i2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, xgene_slimpro_i2c_dt_ids);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id xgene_slimpro_i2c_acpi_ids[] = {
+	{"APMC0D40", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, xgene_slimpro_i2c_acpi_ids);
+#endif
+
+static struct platform_driver xgene_slimpro_i2c_driver = {
+	.probe	= xgene_slimpro_i2c_probe,
+	.remove	= xgene_slimpro_i2c_remove,
+	.driver	= {
+		.name	= "xgene-slimpro-i2c",
+		.of_match_table = of_match_ptr(xgene_slimpro_i2c_dt_ids),
+		.acpi_match_table = ACPI_PTR(xgene_slimpro_i2c_acpi_ids)
+	},
+};
+
+module_platform_driver(xgene_slimpro_i2c_driver);
+
+MODULE_DESCRIPTION("APM X-Gene SLIMpro I2C driver");
+MODULE_AUTHOR("Feng Kan <fkan@apm.com>");
+MODULE_AUTHOR("Hieu Le <hnle@apm.com>");
+MODULE_LICENSE("GPL");

drivers/i2c/busses/i2c-xiic.c

@@ -63,6 +63,7 @@ enum xiic_endian {
  * @state:	See STATE_
  * @rx_msg:	Current RX message
  * @rx_pos:	Position within current RX message
+ * @endianness: big/little-endian byte order
  */
 struct xiic_i2c {
 	void __iomem		*base;

drivers/i2c/i2c-core.c

@@ -257,7 +257,7 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command,
 	struct acpi_connection_info *info = &data->info;
 	struct acpi_resource_i2c_serialbus *sb;
 	struct i2c_adapter *adapter = data->adapter;
-	struct i2c_client client;
+	struct i2c_client *client;
 	struct acpi_resource *ares;
 	u32 accessor_type = function >> 16;
 	u8 action = function & ACPI_IO_MASK;
@@ -268,6 +268,12 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command,
 	if (ACPI_FAILURE(ret))
 		return ret;
 
+	client = kzalloc(sizeof(*client), GFP_KERNEL);
+	if (!client) {
+		ret = AE_NO_MEMORY;
+		goto err;
+	}
+
 	if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) {
 		ret = AE_BAD_PARAMETER;
 		goto err;
@@ -279,75 +285,73 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command,
 		goto err;
 	}
 
-	memset(&client, 0, sizeof(client));
-	client.adapter = adapter;
-	client.addr = sb->slave_address;
-	client.flags = 0;
+	client->adapter = adapter;
+	client->addr = sb->slave_address;
 
 	if (sb->access_mode == ACPI_I2C_10BIT_MODE)
-		client.flags |= I2C_CLIENT_TEN;
+		client->flags |= I2C_CLIENT_TEN;
 
 	switch (accessor_type) {
 	case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
 		if (action == ACPI_READ) {
-			status = i2c_smbus_read_byte(&client);
+			status = i2c_smbus_read_byte(client);
 			if (status >= 0) {
 				gsb->bdata = status;
 				status = 0;
 			}
 		} else {
-			status = i2c_smbus_write_byte(&client, gsb->bdata);
+			status = i2c_smbus_write_byte(client, gsb->bdata);
 		}
 		break;
 
 	case ACPI_GSB_ACCESS_ATTRIB_BYTE:
 		if (action == ACPI_READ) {
-			status = i2c_smbus_read_byte_data(&client, command);
+			status = i2c_smbus_read_byte_data(client, command);
 			if (status >= 0) {
 				gsb->bdata = status;
 				status = 0;
 			}
 		} else {
-			status = i2c_smbus_write_byte_data(&client, command,
+			status = i2c_smbus_write_byte_data(client, command,
 					gsb->bdata);
 		}
 		break;
 
 	case ACPI_GSB_ACCESS_ATTRIB_WORD:
 		if (action == ACPI_READ) {
-			status = i2c_smbus_read_word_data(&client, command);
+			status = i2c_smbus_read_word_data(client, command);
 			if (status >= 0) {
 				gsb->wdata = status;
 				status = 0;
 			}
 		} else {
-			status = i2c_smbus_write_word_data(&client, command,
+			status = i2c_smbus_write_word_data(client, command,
 					gsb->wdata);
 		}
 		break;
 
 	case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
 		if (action == ACPI_READ) {
-			status = i2c_smbus_read_block_data(&client, command,
+			status = i2c_smbus_read_block_data(client, command,
 					gsb->data);
 			if (status >= 0) {
 				gsb->len = status;
 				status = 0;
 			}
 		} else {
-			status = i2c_smbus_write_block_data(&client, command,
+			status = i2c_smbus_write_block_data(client, command,
 					gsb->len, gsb->data);
 		}
 		break;
 
 	case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
 		if (action == ACPI_READ) {
-			status = acpi_gsb_i2c_read_bytes(&client, command,
+			status = acpi_gsb_i2c_read_bytes(client, command,
 					gsb->data, info->access_length);
 			if (status > 0)
 				status = 0;
 		} else {
-			status = acpi_gsb_i2c_write_bytes(&client, command,
+			status = acpi_gsb_i2c_write_bytes(client, command,
 					gsb->data, info->access_length);
 		}
 		break;
@@ -361,6 +365,7 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command,
 	gsb->status = status;
 
  err:
+	kfree(client);
 	ACPI_FREE(ares);
 	return ret;
 }
@@ -1276,7 +1281,7 @@ static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
 	}
 
 	addr = of_get_property(node, "reg", &len);
-	if (!addr || (len < sizeof(int))) {
+	if (!addr || (len < sizeof(*addr))) {
 		dev_err(&adap->dev, "of_i2c: invalid reg on %s\n",
 			node->full_name);
 		return ERR_PTR(-EINVAL);
@@ -1677,7 +1682,7 @@ void i2c_del_adapter(struct i2c_adapter *adap)
 	 * FIXME: This is old code and should ideally be replaced by an
 	 * alternative which results in decoupling the lifetime of the struct
 	 * device from the i2c_adapter, like spi or netdev do. Any solution
-	 * should be throughly tested with DEBUG_KOBJECT_RELEASE enabled!
+	 * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled!
 	 */
 	init_completion(&adap->dev_released);
 	device_unregister(&adap->dev);
@@ -2918,18 +2923,24 @@ int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb)
 {
 	int ret;
 
-	if (!client || !slave_cb)
+	if (!client || !slave_cb) {
+		WARN(1, "insufficent data\n");
 		return -EINVAL;
+	}
 
 	if (!(client->flags & I2C_CLIENT_TEN)) {
 		/* Enforce stricter address checking */
 		ret = i2c_check_addr_validity(client->addr);
-		if (ret)
+		if (ret) {
+			dev_err(&client->dev, "%s: invalid address\n", __func__);
 			return ret;
+		}
 	}
 
-	if (!client->adapter->algo->reg_slave)
+	if (!client->adapter->algo->reg_slave) {
+		dev_err(&client->dev, "%s: not supported by adapter\n", __func__);
 		return -EOPNOTSUPP;
+	}
 
 	client->slave_cb = slave_cb;
 
@@ -2937,8 +2948,10 @@ int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb)
 	ret = client->adapter->algo->reg_slave(client);
 	i2c_unlock_adapter(client->adapter);
 
-	if (ret)
+	if (ret) {
 		client->slave_cb = NULL;
+		dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret);
+	}
 
 	return ret;
 }
@@ -2948,8 +2961,10 @@ int i2c_slave_unregister(struct i2c_client *client)
 {
 	int ret;
 
-	if (!client->adapter->algo->unreg_slave)
+	if (!client->adapter->algo->unreg_slave) {
+		dev_err(&client->dev, "%s: not supported by adapter\n", __func__);
 		return -EOPNOTSUPP;
+	}
 
 	i2c_lock_adapter(client->adapter);
 	ret = client->adapter->algo->unreg_slave(client);
@@ -2957,6 +2972,8 @@ int i2c_slave_unregister(struct i2c_client *client)
 
 	if (ret == 0)
 		client->slave_cb = NULL;
+	else
+		dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret);
 
 	return ret;
 }

drivers/i2c/i2c-mux.c

@@ -51,7 +51,7 @@ static int i2c_mux_master_xfer(struct i2c_adapter *adap,
 
 	ret = priv->select(parent, priv->mux_priv, priv->chan_id);
 	if (ret >= 0)
-		ret = parent->algo->master_xfer(parent, msgs, num);
+		ret = __i2c_transfer(parent, msgs, num);
 	if (priv->deselect)
 		priv->deselect(parent, priv->mux_priv, priv->chan_id);
 
@@ -144,6 +144,7 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
 	priv->adap.dev.parent = &parent->dev;
 	priv->adap.retries = parent->retries;
 	priv->adap.timeout = parent->timeout;
+	priv->adap.quirks = parent->quirks;
 
 	/* Sanity check on class */
 	if (i2c_mux_parent_classes(parent) & class)

drivers/i2c/i2c-smbus.c

@@ -89,7 +89,7 @@ static void smbus_alert(struct work_struct *work)
 		 * to high, because of slave transmit arbitration.  After
 		 * responding, an SMBus device stops asserting SMBALERT#.
 		 *
-		 * Note that SMBus 2.0 reserves 10-bit addresess for future
+		 * Note that SMBus 2.0 reserves 10-bit addresses for future
 		 * use.  We neither handle them, nor try to use PEC here.
 		 */
 		status = i2c_smbus_read_byte(ara);

drivers/i2c/muxes/Kconfig

@@ -7,7 +7,8 @@ menu "Multiplexer I2C Chip support"
 
 config I2C_ARB_GPIO_CHALLENGE
 	tristate "GPIO-based I2C arbitration"
-	depends on GPIOLIB && OF
+	depends on GPIOLIB || COMPILE_TEST
+	depends on OF
 	help
 	  If you say yes to this option, support will be included for an
 	  I2C multimaster arbitration scheme using GPIOs and a challenge &
@@ -40,7 +41,7 @@ config I2C_MUX_PCA9541
 
 config I2C_MUX_PCA954x
 	tristate "Philips PCA954x I2C Mux/switches"
-	depends on GPIOLIB
+	depends on GPIOLIB || COMPILE_TEST
 	help
 	  If you say yes here you get support for the Philips PCA954x
 	  I2C mux/switch devices.

drivers/i2c/muxes/i2c-mux-pca9541.c

@@ -104,7 +104,7 @@ static int pca9541_reg_write(struct i2c_client *client, u8 command, u8 val)
 		buf[0] = command;
 		buf[1] = val;
 		msg.buf = buf;
-		ret = adap->algo->master_xfer(adap, &msg, 1);
+		ret = __i2c_transfer(adap, &msg, 1);
 	} else {
 		union i2c_smbus_data data;
 
@@ -144,7 +144,7 @@ static int pca9541_reg_read(struct i2c_client *client, u8 command)
 				.buf = &val
 			}
 		};
-		ret = adap->algo->master_xfer(adap, msg, 2);
+		ret = __i2c_transfer(adap, msg, 2);
 		if (ret == 2)
 			ret = val;
 		else if (ret >= 0)

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

@@ -134,7 +134,7 @@ static int pca954x_reg_write(struct i2c_adapter *adap,
 		msg.len = 1;
 		buf[0] = val;
 		msg.buf = buf;
-		ret = adap->algo->master_xfer(adap, &msg, 1);
+		ret = __i2c_transfer(adap, &msg, 1);
 	} else {
 		union i2c_smbus_data data;
 		ret = adap->algo->smbus_xfer(adap, client->addr,

include/uapi/linux/i2c.h

@@ -87,6 +87,7 @@ struct i2c_msg {
 #define I2C_FUNC_PROTOCOL_MANGLING	0x00000004 /* I2C_M_IGNORE_NAK etc. */
 #define I2C_FUNC_SMBUS_PEC		0x00000008
 #define I2C_FUNC_NOSTART		0x00000010 /* I2C_M_NOSTART */
+#define I2C_FUNC_SLAVE			0x00000020
 #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL	0x00008000 /* SMBus 2.0 */
 #define I2C_FUNC_SMBUS_QUICK		0x00010000
 #define I2C_FUNC_SMBUS_READ_BYTE	0x00020000