Merge branch 'i2c-embedded/for-3.4' of git://git.pengutronix.de/git/wsa/linux

Pull i2c embedded updates from Wolfram Sang:
 "Nothing special from i2c-embedded for this merge window.  Two new
  drivers, minor feature additions, bugfixes, cleanups.

  All patches have been in linux-next for some time, too."

* 'i2c-embedded/for-3.4' of git://git.pengutronix.de/git/wsa/linux:
  i2c-eg20t: Remove write-only variables
  i2c-eg20t: Rework pch_i2c_wait_for_bus_idle to reduce wait time
  i2c-s3c2410: Add stub runtime power management
  i2c-s3c2410: Convert to devm_kzalloc()
  i2c: add CSR SiRFprimaII on-chip I2C controllers driver
  i2c: tegra: Remove unnecessary write to INT_STATUS
  i2c: imx: fix imx driver to work though signal is pending
  i2c: designware: dw_i2c_init_driver as subsys initcall
  misc: at24: describe platform_data with kernel_doc
  i2c: Move I2C_EG20T option to the right place.
  i2c: Support for Netlogic XLR/XLS I2C controller.
  i2c: mpc: Add support for SMBUS_READ_BLOCK_DATA
  i2c: versatile: Add Device Tree support

13 files changed, 912 insertions, 66 deletions

diff --git a/Documentation/devicetree/bindings/i2c/sirf-i2c.txt b/Documentation/devicetree/bindings/i2c/sirf-i2c.txt
new file mode 100644
index 000000000000..7baf9e133fa8
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/sirf-i2c.txt
@@ -0,0 +1,19 @@
+I2C for SiRFprimaII platforms
+
+Required properties :
+- compatible : Must be "sirf,prima2-i2c"
+- reg: physical base address of the controller and length of memory mapped
+     region.
+- interrupts: interrupt number to the cpu.
+
+Optional properties:
+- clock-frequency : Constains desired I2C/HS-I2C bus clock frequency in Hz.
+  The absence of the propoerty indicates the default frequency 100 kHz.
+
+Examples :
+
+i2c0: i2c@b00e0000 {
+    compatible = "sirf,prima2-i2c";
+    reg = <0xb00e0000 0x10000>;
+    interrupts = <24>;
+};
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 3101dd59e379..71c1b0a7535c 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -369,6 +369,21 @@ config I2C_DESIGNWARE_PCI
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-designware-pci.
 
+config I2C_EG20T
+	tristate "Intel EG20T PCH/LAPIS Semicon IOH(ML7213/ML7223/ML7831) I2C"
+	depends on PCI
+	help
+	  This driver is for PCH(Platform controller Hub) I2C of EG20T which
+	  is an IOH(Input/Output Hub) for x86 embedded processor.
+	  This driver can access PCH I2C bus device.
+
+	  This driver also can be used for LAPIS Semiconductor IOH(Input/
+	  Output Hub), ML7213, ML7223 and ML7831.
+	  ML7213 IOH is for IVI(In-Vehicle Infotainment) use, ML7223 IOH is
+	  for MP(Media Phone) use and ML7831 IOH is for general purpose use.
+	  ML7213/ML7223/ML7831 is companion chip for Intel Atom E6xx series.
+	  ML7213/ML7223/ML7831 is completely compatible for Intel EG20T PCH.
+
 config I2C_GPIO
 	tristate "GPIO-based bitbanging I2C"
 	depends on GENERIC_GPIO
@@ -630,6 +645,16 @@ config I2C_SIMTEC
 	  This driver can also be built as a module. If so, the module
 	  will be called i2c-simtec.
 
+config I2C_SIRF
+	tristate "CSR SiRFprimaII I2C interface"
+	depends on ARCH_PRIMA2
+	help
+	  If you say yes to this option, support will be included for the
+	  CSR SiRFprimaII I2C interface.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-sirf.
+
 config I2C_STU300
 	tristate "ST Microelectronics DDC I2C interface"
 	depends on MACH_U300
@@ -681,20 +706,15 @@ config I2C_XILINX
 	  This driver can also be built as a module.  If so, the module
 	  will be called xilinx_i2c.
 
-config I2C_EG20T
-	tristate "Intel EG20T PCH/LAPIS Semicon IOH(ML7213/ML7223/ML7831) I2C"
-	depends on PCI
+config I2C_XLR
+	tristate "XLR I2C support"
+	depends on CPU_XLR
 	help
-	  This driver is for PCH(Platform controller Hub) I2C of EG20T which
-	  is an IOH(Input/Output Hub) for x86 embedded processor.
-	  This driver can access PCH I2C bus device.
+	  This driver enables support for the on-chip I2C interface of
+	  the Netlogic XLR/XLS MIPS processors.
 
-	  This driver also can be used for LAPIS Semiconductor IOH(Input/
-	  Output Hub), ML7213, ML7223 and ML7831.
-	  ML7213 IOH is for IVI(In-Vehicle Infotainment) use, ML7223 IOH is
-	  for MP(Media Phone) use and ML7831 IOH is for general purpose use.
-	  ML7213/ML7223/ML7831 is companion chip for Intel Atom E6xx series.
-	  ML7213/ML7223/ML7831 is completely compatible for Intel EG20T PCH.
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-xlr.
 
 comment "External I2C/SMBus adapter drivers"
 
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index fba6da60aa0e..569567b0d027 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM)	+= i2c-designware-platform.o
 i2c-designware-platform-objs := i2c-designware-platdrv.o i2c-designware-core.o
 obj-$(CONFIG_I2C_DESIGNWARE_PCI)	+= i2c-designware-pci.o
 i2c-designware-pci-objs := i2c-designware-pcidrv.o i2c-designware-core.o
+obj-$(CONFIG_I2C_EG20T)		+= i2c-eg20t.o
 obj-$(CONFIG_I2C_GPIO)		+= i2c-gpio.o
 obj-$(CONFIG_I2C_HIGHLANDER)	+= i2c-highlander.o
 obj-$(CONFIG_I2C_IBM_IIC)	+= i2c-ibm_iic.o
@@ -63,12 +64,13 @@ obj-$(CONFIG_I2C_S6000)		+= i2c-s6000.o
 obj-$(CONFIG_I2C_SH7760)	+= i2c-sh7760.o
 obj-$(CONFIG_I2C_SH_MOBILE)	+= i2c-sh_mobile.o
 obj-$(CONFIG_I2C_SIMTEC)	+= i2c-simtec.o
+obj-$(CONFIG_I2C_SIRF)		+= i2c-sirf.o
 obj-$(CONFIG_I2C_STU300)	+= i2c-stu300.o
 obj-$(CONFIG_I2C_TEGRA)		+= i2c-tegra.o
 obj-$(CONFIG_I2C_VERSATILE)	+= i2c-versatile.o
 obj-$(CONFIG_I2C_OCTEON)	+= i2c-octeon.o
 obj-$(CONFIG_I2C_XILINX)	+= i2c-xiic.o
-obj-$(CONFIG_I2C_EG20T)         += i2c-eg20t.o
+obj-$(CONFIG_I2C_XLR)		+= i2c-xlr.o
 
 # External I2C/SMBus adapter drivers
 obj-$(CONFIG_I2C_DIOLAN_U2C)	+= i2c-diolan-u2c.o
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 5244c4724df7..4ba589ab8614 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -214,7 +214,7 @@ static int __init dw_i2c_init_driver(void)
 {
 	return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
 }
-module_init(dw_i2c_init_driver);
+subsys_initcall(dw_i2c_init_driver);
 
 static void __exit dw_i2c_exit_driver(void)
 {
diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
index ca8877641040..f086131cb1c7 100644
--- a/drivers/i2c/busses/i2c-eg20t.c
+++ b/drivers/i2c/busses/i2c-eg20t.c
@@ -271,30 +271,36 @@ static inline bool ktime_lt(const ktime_t cmp1, const ktime_t cmp2)
 /**
  * pch_i2c_wait_for_bus_idle() - check the status of bus.
  * @adap:	Pointer to struct i2c_algo_pch_data.
- * @timeout:	waiting time counter (us).
+ * @timeout:	waiting time counter (ms).
  */
 static s32 pch_i2c_wait_for_bus_idle(struct i2c_algo_pch_data *adap,
 				     s32 timeout)
 {
 	void __iomem *p = adap->pch_base_address;
-	ktime_t ns_val;
+	int schedule = 0;
+	unsigned long end = jiffies + msecs_to_jiffies(timeout);
+
+	while (ioread32(p + PCH_I2CSR) & I2CMBB_BIT) {
+		if (time_after(jiffies, end)) {
+			pch_dbg(adap, "I2CSR = %x\n", ioread32(p + PCH_I2CSR));
+			pch_err(adap, "%s: Timeout Error.return%d\n",
+					__func__, -ETIME);
+			pch_i2c_init(adap);
 
-	if ((ioread32(p + PCH_I2CSR) & I2CMBB_BIT) == 0)
-		return 0;
+			return -ETIME;
+		}
 
-	/* MAX timeout value is timeout*1000*1000nsec */
-	ns_val = ktime_add_ns(ktime_get(), timeout*1000*1000);
-	do {
-		msleep(20);
-		if ((ioread32(p + PCH_I2CSR) & I2CMBB_BIT) == 0)
-			return 0;
-	} while (ktime_lt(ktime_get(), ns_val));
+		if (!schedule)
+			/* Retry after some usecs */
+			udelay(5);
+		else
+			/* Wait a bit more without consuming CPU */
+			usleep_range(20, 1000);
 
-	pch_dbg(adap, "I2CSR = %x\n", ioread32(p + PCH_I2CSR));
-	pch_err(adap, "%s: Timeout Error.return%d\n", __func__, -ETIME);
-	pch_i2c_init(adap);
+		schedule = 1;
+	}
 
-	return -ETIME;
+	return 0;
 }
 
 /**
@@ -778,8 +784,6 @@ static s32 pch_i2c_xfer(struct i2c_adapter *i2c_adap,
 	struct i2c_msg *pmsg;
 	u32 i = 0;
 	u32 status;
-	u32 msglen;
-	u32 subaddrlen;
 	s32 ret;
 
 	struct i2c_algo_pch_data *adap = i2c_adap->algo_data;
@@ -804,12 +808,6 @@ static s32 pch_i2c_xfer(struct i2c_adapter *i2c_adap,
 		status = pmsg->flags;
 		pch_dbg(adap,
 			"After invoking I2C_MODE_SEL :flag= 0x%x\n", status);
-		/* calculate sub address length and message length */
-		/* these are applicable only for buffer mode */
-		subaddrlen = pmsg->buf[0];
-		/* calculate actual message length excluding
-		 * the sub address fields */
-		msglen = (pmsg->len) - (subaddrlen + 1);
 
 		if ((status & (I2C_M_RD)) != false) {
 			ret = pch_i2c_readbytes(i2c_adap, pmsg, (i + 1 == num),
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 58832e578fff..124d9c594f40 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -149,11 +149,6 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
 			break;
 		if (!for_busy && !(temp & I2SR_IBB))
 			break;
-		if (signal_pending(current)) {
-			dev_dbg(&i2c_imx->adapter.dev,
-				"<%s> I2C Interrupted\n", __func__);
-			return -EINTR;
-		}
 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
 			dev_dbg(&i2c_imx->adapter.dev,
 				"<%s> I2C bus is busy\n", __func__);
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index a8ebb84e23f9..206caacd30d7 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -454,7 +454,7 @@ static int mpc_write(struct mpc_i2c *i2c, int target,
 }
 
 static int mpc_read(struct mpc_i2c *i2c, int target,
-		    u8 *data, int length, int restart)
+		    u8 *data, int length, int restart, bool recv_len)
 {
 	unsigned timeout = i2c->adap.timeout;
 	int i, result;
@@ -470,7 +470,7 @@ static int mpc_read(struct mpc_i2c *i2c, int target,
 		return result;
 
 	if (length) {
-		if (length == 1)
+		if (length == 1 && !recv_len)
 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
 		else
 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
@@ -479,17 +479,46 @@ static int mpc_read(struct mpc_i2c *i2c, int target,
 	}
 
 	for (i = 0; i < length; i++) {
+		u8 byte;
+
 		result = i2c_wait(i2c, timeout, 0);
 		if (result < 0)
 			return result;
 
-		/* Generate txack on next to last byte */
-		if (i == length - 2)
-			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
-		/* Do not generate stop on last byte */
-		if (i == length - 1)
-			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX);
-		data[i] = readb(i2c->base + MPC_I2C_DR);
+		/*
+		 * For block reads, we have to know the total length (1st byte)
+		 * before we can determine if we are done.
+		 */
+		if (i || !recv_len) {
+			/* Generate txack on next to last byte */
+			if (i == length - 2)
+				writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+					 | CCR_TXAK);
+			/* Do not generate stop on last byte */
+			if (i == length - 1)
+				writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+					 | CCR_MTX);
+		}
+
+		byte = readb(i2c->base + MPC_I2C_DR);
+
+		/*
+		 * Adjust length if first received byte is length.
+		 * The length is 1 length byte plus actually data length
+		 */
+		if (i == 0 && recv_len) {
+			if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX)
+				return -EPROTO;
+			length += byte;
+			/*
+			 * For block reads, generate txack here if data length
+			 * is 1 byte (total length is 2 bytes).
+			 */
+			if (length == 2)
+				writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+					 | CCR_TXAK);
+		}
+		data[i] = byte;
 	}
 
 	return length;
@@ -532,12 +561,17 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 			"Doing %s %d bytes to 0x%02x - %d of %d messages\n",
 			pmsg->flags & I2C_M_RD ? "read" : "write",
 			pmsg->len, pmsg->addr, i + 1, num);
-		if (pmsg->flags & I2C_M_RD)
-			ret =
-			    mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
-		else
+		if (pmsg->flags & I2C_M_RD) {
+			bool recv_len = pmsg->flags & I2C_M_RECV_LEN;
+
+			ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i,
+				       recv_len);
+			if (recv_len && ret > 0)
+				pmsg->len = ret;
+		} else {
 			ret =
 			    mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
+		}
 	}
 	mpc_i2c_stop(i2c);
 	return (ret < 0) ? ret : num;
@@ -545,7 +579,8 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 
 static u32 mpc_functionality(struct i2c_adapter *adap)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
+	  | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 }
 
 static const struct i2c_algorithm mpc_algo = {
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 4c1718081685..737f7218a32c 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -31,6 +31,7 @@
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/clk.h>
 #include <linux/cpufreq.h>
 #include <linux/slab.h>
@@ -564,6 +565,7 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
 	int retry;
 	int ret;
 
+	pm_runtime_get_sync(&adap->dev);
 	clk_enable(i2c->clk);
 
 	for (retry = 0; retry < adap->retries; retry++) {
@@ -572,6 +574,7 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
 
 		if (ret != -EAGAIN) {
 			clk_disable(i2c->clk);
+			pm_runtime_put_sync(&adap->dev);
 			return ret;
 		}
 
@@ -581,6 +584,7 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
 	}
 
 	clk_disable(i2c->clk);
+	pm_runtime_put_sync(&adap->dev);
 	return -EREMOTEIO;
 }
 
@@ -890,7 +894,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
 		}
 	}
 
-	i2c = kzalloc(sizeof(struct s3c24xx_i2c), GFP_KERNEL);
+	i2c = devm_kzalloc(&pdev->dev, sizeof(struct s3c24xx_i2c), GFP_KERNEL);
 	if (!i2c) {
 		dev_err(&pdev->dev, "no memory for state\n");
 		return -ENOMEM;
@@ -1013,6 +1017,9 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
 	of_i2c_register_devices(&i2c->adap);
 	platform_set_drvdata(pdev, i2c);
 
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_enable(&i2c->adap.dev);
+
 	dev_info(&pdev->dev, "%s: S3C I2C adapter\n", dev_name(&i2c->adap.dev));
 	clk_disable(i2c->clk);
 	return 0;
@@ -1035,7 +1042,6 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
 	clk_put(i2c->clk);
 
  err_noclk:
-	kfree(i2c);
 	return ret;
 }
 
@@ -1048,6 +1054,9 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev)
 {
 	struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
 
+	pm_runtime_disable(&i2c->adap.dev);
+	pm_runtime_disable(&pdev->dev);
+
 	s3c24xx_i2c_deregister_cpufreq(i2c);
 
 	i2c_del_adapter(&i2c->adap);
@@ -1061,7 +1070,6 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev)
 	release_resource(i2c->ioarea);
 	s3c24xx_i2c_dt_gpio_free(i2c);
 	kfree(i2c->ioarea);
-	kfree(i2c);
 
 	return 0;
 }
diff --git a/drivers/i2c/busses/i2c-sirf.c b/drivers/i2c/busses/i2c-sirf.c
new file mode 100644
index 000000000000..5574a47792fb
--- /dev/null
+++ b/drivers/i2c/busses/i2c-sirf.c
@@ -0,0 +1,459 @@
+/*
+ * I2C bus driver for CSR SiRFprimaII
+ *
+ * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#define SIRFSOC_I2C_CLK_CTRL		0x00
+#define SIRFSOC_I2C_STATUS		0x0C
+#define SIRFSOC_I2C_CTRL		0x10
+#define SIRFSOC_I2C_IO_CTRL		0x14
+#define SIRFSOC_I2C_SDA_DELAY		0x18
+#define SIRFSOC_I2C_CMD_START		0x1C
+#define SIRFSOC_I2C_CMD_BUF		0x30
+#define SIRFSOC_I2C_DATA_BUF		0x80
+
+#define SIRFSOC_I2C_CMD_BUF_MAX		16
+#define SIRFSOC_I2C_DATA_BUF_MAX	16
+
+#define SIRFSOC_I2C_CMD(x)		(SIRFSOC_I2C_CMD_BUF + (x)*0x04)
+#define SIRFSOC_I2C_DATA_MASK(x)        (0xFF<<(((x)&3)*8))
+#define SIRFSOC_I2C_DATA_SHIFT(x)       (((x)&3)*8)
+
+#define SIRFSOC_I2C_DIV_MASK		(0xFFFF)
+
+/* I2C status flags */
+#define SIRFSOC_I2C_STAT_BUSY		BIT(0)
+#define SIRFSOC_I2C_STAT_TIP		BIT(1)
+#define SIRFSOC_I2C_STAT_NACK		BIT(2)
+#define SIRFSOC_I2C_STAT_TR_INT		BIT(4)
+#define SIRFSOC_I2C_STAT_STOP		BIT(6)
+#define SIRFSOC_I2C_STAT_CMD_DONE	BIT(8)
+#define SIRFSOC_I2C_STAT_ERR		BIT(9)
+#define SIRFSOC_I2C_CMD_INDEX		(0x1F<<16)
+
+/* I2C control flags */
+#define SIRFSOC_I2C_RESET		BIT(0)
+#define SIRFSOC_I2C_CORE_EN		BIT(1)
+#define SIRFSOC_I2C_MASTER_MODE		BIT(2)
+#define SIRFSOC_I2C_CMD_DONE_EN		BIT(11)
+#define SIRFSOC_I2C_ERR_INT_EN		BIT(12)
+
+#define SIRFSOC_I2C_SDA_DELAY_MASK	(0xFF)
+#define SIRFSOC_I2C_SCLF_FILTER		(3<<8)
+
+#define SIRFSOC_I2C_START_CMD		BIT(0)
+
+#define SIRFSOC_I2C_CMD_RP(x)		((x)&0x7)
+#define SIRFSOC_I2C_NACK		BIT(3)
+#define SIRFSOC_I2C_WRITE		BIT(4)
+#define SIRFSOC_I2C_READ		BIT(5)
+#define SIRFSOC_I2C_STOP		BIT(6)
+#define SIRFSOC_I2C_START		BIT(7)
+
+#define SIRFSOC_I2C_DEFAULT_SPEED 100000
+
+struct sirfsoc_i2c {
+	void __iomem *base;
+	struct clk *clk;
+	u32 cmd_ptr;		/* Current position in CMD buffer */
+	u8 *buf;		/* Buffer passed by user */
+	u32 msg_len;		/* Message length */
+	u32 finished_len;	/* number of bytes read/written */
+	u32 read_cmd_len;	/* number of read cmd sent */
+	int msg_read;		/* 1 indicates a read message */
+	int err_status;		/* 1 indicates an error on bus */
+
+	u32 sda_delay;		/* For suspend/resume */
+	u32 clk_div;
+	int last;		/* Last message in transfer, STOP cmd can be sent */
+
+	struct completion done;	/* indicates completion of message transfer */
+	struct i2c_adapter adapter;
+};
+
+static void i2c_sirfsoc_read_data(struct sirfsoc_i2c *siic)
+{
+	u32 data = 0;
+	int i;
+
+	for (i = 0; i < siic->read_cmd_len; i++) {
+		if (!(i & 0x3))
+			data = readl(siic->base + SIRFSOC_I2C_DATA_BUF + i);
+		siic->buf[siic->finished_len++] =
+			(u8)((data & SIRFSOC_I2C_DATA_MASK(i)) >>
+				SIRFSOC_I2C_DATA_SHIFT(i));
+	}
+}
+
+static void i2c_sirfsoc_queue_cmd(struct sirfsoc_i2c *siic)
+{
+	u32 regval;
+	int i = 0;
+
+	if (siic->msg_read) {
+		while (((siic->finished_len + i) < siic->msg_len)
+				&& (siic->cmd_ptr < SIRFSOC_I2C_CMD_BUF_MAX)) {
+			regval = SIRFSOC_I2C_READ | SIRFSOC_I2C_CMD_RP(0);
+			if (((siic->finished_len + i) ==
+					(siic->msg_len - 1)) && siic->last)
+				regval |= SIRFSOC_I2C_STOP | SIRFSOC_I2C_NACK;
+			writel(regval,
+				siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
+			i++;
+		}
+
+		siic->read_cmd_len = i;
+	} else {
+		while ((siic->cmd_ptr < SIRFSOC_I2C_CMD_BUF_MAX - 1)
+				&& (siic->finished_len < siic->msg_len)) {
+			regval = SIRFSOC_I2C_WRITE | SIRFSOC_I2C_CMD_RP(0);
+			if ((siic->finished_len == (siic->msg_len - 1))
+				&& siic->last)
+				regval |= SIRFSOC_I2C_STOP;
+			writel(regval,
+				siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
+			writel(siic->buf[siic->finished_len++],
+				siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
+		}
+	}
+	siic->cmd_ptr = 0;
+
+	/* Trigger the transfer */
+	writel(SIRFSOC_I2C_START_CMD, siic->base + SIRFSOC_I2C_CMD_START);
+}
+
+static irqreturn_t i2c_sirfsoc_irq(int irq, void *dev_id)
+{
+	struct sirfsoc_i2c *siic = (struct sirfsoc_i2c *)dev_id;
+	u32 i2c_stat = readl(siic->base + SIRFSOC_I2C_STATUS);
+
+	if (i2c_stat & SIRFSOC_I2C_STAT_ERR) {
+		/* Error conditions */
+		siic->err_status = 1;
+		writel(SIRFSOC_I2C_STAT_ERR, siic->base + SIRFSOC_I2C_STATUS);
+
+		if (i2c_stat & SIRFSOC_I2C_STAT_NACK)
+			dev_err(&siic->adapter.dev, "ACK not received\n");
+		else
+			dev_err(&siic->adapter.dev, "I2C error\n");
+
+		complete(&siic->done);
+	} else if (i2c_stat & SIRFSOC_I2C_STAT_CMD_DONE) {
+		/* CMD buffer execution complete */
+		if (siic->msg_read)
+			i2c_sirfsoc_read_data(siic);
+		if (siic->finished_len == siic->msg_len)
+			complete(&siic->done);
+		else /* Fill a new CMD buffer for left data */
+			i2c_sirfsoc_queue_cmd(siic);
+
+		writel(SIRFSOC_I2C_STAT_CMD_DONE, siic->base + SIRFSOC_I2C_STATUS);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void i2c_sirfsoc_set_address(struct sirfsoc_i2c *siic,
+	struct i2c_msg *msg)
+{
+	unsigned char addr;
+	u32 regval = SIRFSOC_I2C_START | SIRFSOC_I2C_CMD_RP(0) | SIRFSOC_I2C_WRITE;
+
+	/* no data and last message -> add STOP */
+	if (siic->last && (msg->len == 0))
+		regval |= SIRFSOC_I2C_STOP;
+
+	writel(regval, siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
+
+	addr = msg->addr << 1;	/* Generate address */
+	if (msg->flags & I2C_M_RD)
+		addr |= 1;
+
+	writel(addr, siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
+}
+
+static int i2c_sirfsoc_xfer_msg(struct sirfsoc_i2c *siic, struct i2c_msg *msg)
+{
+	u32 regval = readl(siic->base + SIRFSOC_I2C_CTRL);
+	/* timeout waiting for the xfer to finish or fail */
+	int timeout = msecs_to_jiffies((msg->len + 1) * 50);
+	int ret = 0;
+
+	i2c_sirfsoc_set_address(siic, msg);
+
+	writel(regval | SIRFSOC_I2C_CMD_DONE_EN | SIRFSOC_I2C_ERR_INT_EN,
+		siic->base + SIRFSOC_I2C_CTRL);
+	i2c_sirfsoc_queue_cmd(siic);
+
+	if (wait_for_completion_timeout(&siic->done, timeout) == 0) {
+		siic->err_status = 1;
+		dev_err(&siic->adapter.dev, "Transfer timeout\n");
+	}
+
+	writel(regval & ~(SIRFSOC_I2C_CMD_DONE_EN | SIRFSOC_I2C_ERR_INT_EN),
+		siic->base + SIRFSOC_I2C_CTRL);
+	writel(0, siic->base + SIRFSOC_I2C_CMD_START);
+
+	if (siic->err_status) {
+		writel(readl(siic->base + SIRFSOC_I2C_CTRL) | SIRFSOC_I2C_RESET,
+			siic->base + SIRFSOC_I2C_CTRL);
+		while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET)
+			cpu_relax();
+
+		ret = -EIO;
+	}
+
+	return ret;
+}
+
+static u32 i2c_sirfsoc_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static int i2c_sirfsoc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+	int num)
+{
+	struct sirfsoc_i2c *siic = adap->algo_data;
+	int i, ret;
+
+	clk_enable(siic->clk);
+
+	for (i = 0; i < num; i++) {
+		siic->buf = msgs[i].buf;
+		siic->msg_len = msgs[i].len;
+		siic->msg_read = !!(msgs[i].flags & I2C_M_RD);
+		siic->err_status = 0;
+		siic->cmd_ptr = 0;
+		siic->finished_len = 0;
+		siic->last = (i == (num - 1));
+
+		ret = i2c_sirfsoc_xfer_msg(siic, &msgs[i]);
+		if (ret) {
+			clk_disable(siic->clk);
+			return ret;
+		}
+	}
+
+	clk_disable(siic->clk);
+	return num;
+}
+
+/* I2C algorithms associated with this master controller driver */
+static const struct i2c_algorithm i2c_sirfsoc_algo = {
+	.master_xfer = i2c_sirfsoc_xfer,
+	.functionality = i2c_sirfsoc_func,
+};
+
+static int __devinit i2c_sirfsoc_probe(struct platform_device *pdev)
+{
+	struct sirfsoc_i2c *siic;
+	struct i2c_adapter *adap;
+	struct resource *mem_res;
+	struct clk *clk;
+	int bitrate;
+	int ctrl_speed;
+	int irq;
+
+	int err;
+	u32 regval;
+
+	clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		err = PTR_ERR(clk);
+		dev_err(&pdev->dev, "Clock get failed\n");
+		goto err_get_clk;
+	}
+
+	err = clk_prepare(clk);
+	if (err) {
+		dev_err(&pdev->dev, "Clock prepare failed\n");
+		goto err_clk_prep;
+	}
+
+	err = clk_enable(clk);
+	if (err) {
+		dev_err(&pdev->dev, "Clock enable failed\n");
+		goto err_clk_en;
+	}
+
+	ctrl_speed = clk_get_rate(clk);
+
+	siic = devm_kzalloc(&pdev->dev, sizeof(*siic), GFP_KERNEL);
+	if (!siic) {
+		dev_err(&pdev->dev, "Can't allocate driver data\n");
+		err = -ENOMEM;
+		goto out;
+	}
+	adap = &siic->adapter;
+	adap->class = I2C_CLASS_HWMON;
+
+	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (mem_res == NULL) {
+		dev_err(&pdev->dev, "Unable to get MEM resource\n");
+		err = -EINVAL;
+		goto out;
+	}
+
+	siic->base = devm_request_and_ioremap(&pdev->dev, mem_res);
+	if (siic->base == NULL) {
+		dev_err(&pdev->dev, "IO remap failed!\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		err = irq;
+		goto out;
+	}
+	err = devm_request_irq(&pdev->dev, irq, i2c_sirfsoc_irq, 0,
+		dev_name(&pdev->dev), siic);
+	if (err)
+		goto out;
+
+	adap->algo = &i2c_sirfsoc_algo;
+	adap->algo_data = siic;
+
+	adap->dev.parent = &pdev->dev;
+	adap->nr = pdev->id;
+
+	strlcpy(adap->name, "sirfsoc-i2c", sizeof(adap->name));
+
+	platform_set_drvdata(pdev, adap);
+	init_completion(&siic->done);
+
+	/* Controller Initalisation */
+
+	writel(SIRFSOC_I2C_RESET, siic->base + SIRFSOC_I2C_CTRL);
+	while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET)
+		cpu_relax();
+	writel(SIRFSOC_I2C_CORE_EN | SIRFSOC_I2C_MASTER_MODE,
+		siic->base + SIRFSOC_I2C_CTRL);
+
+	siic->clk = clk;
+
+	err = of_property_read_u32(pdev->dev.of_node,
+		"clock-frequency", &bitrate);
+	if (err < 0)
+		bitrate = SIRFSOC_I2C_DEFAULT_SPEED;
+
+	if (bitrate < 100000)
+		regval =
+			(2 * ctrl_speed) / (2 * bitrate * 11);
+	else
+		regval = ctrl_speed / (bitrate * 5);
+
+	writel(regval, siic->base + SIRFSOC_I2C_CLK_CTRL);
+	if (regval > 0xFF)
+		writel(0xFF, siic->base + SIRFSOC_I2C_SDA_DELAY);
+	else
+		writel(regval, siic->base + SIRFSOC_I2C_SDA_DELAY);
+
+	err = i2c_add_numbered_adapter(adap);
+	if (err < 0) {
+		dev_err(&pdev->dev, "Can't add new i2c adapter\n");
+		goto out;
+	}
+
+	clk_disable(clk);
+
+	dev_info(&pdev->dev, " I2C adapter ready to operate\n");
+
+	return 0;
+
+out:
+	clk_disable(clk);
+err_clk_en:
+	clk_unprepare(clk);
+err_clk_prep:
+	clk_put(clk);
+err_get_clk:
+	return err;
+}
+
+static int __devexit i2c_sirfsoc_remove(struct platform_device *pdev)
+{
+	struct i2c_adapter *adapter = platform_get_drvdata(pdev);
+	struct sirfsoc_i2c *siic = adapter->algo_data;
+
+	writel(SIRFSOC_I2C_RESET, siic->base + SIRFSOC_I2C_CTRL);
+	i2c_del_adapter(adapter);
+	clk_unprepare(siic->clk);
+	clk_put(siic->clk);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int i2c_sirfsoc_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct i2c_adapter *adapter = platform_get_drvdata(pdev);
+	struct sirfsoc_i2c *siic = adapter->algo_data;
+
+	clk_enable(siic->clk);
+	siic->sda_delay = readl(siic->base + SIRFSOC_I2C_SDA_DELAY);
+	siic->clk_div = readl(siic->base + SIRFSOC_I2C_CLK_CTRL);
+	clk_disable(siic->clk);
+	return 0;
+}
+
+static int i2c_sirfsoc_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct i2c_adapter *adapter = platform_get_drvdata(pdev);
+	struct sirfsoc_i2c *siic = adapter->algo_data;
+
+	clk_enable(siic->clk);
+	writel(SIRFSOC_I2C_RESET, siic->base + SIRFSOC_I2C_CTRL);
+	writel(SIRFSOC_I2C_CORE_EN | SIRFSOC_I2C_MASTER_MODE,
+		siic->base + SIRFSOC_I2C_CTRL);
+	writel(siic->clk_div, siic->base + SIRFSOC_I2C_CLK_CTRL);
+	writel(siic->sda_delay, siic->base + SIRFSOC_I2C_SDA_DELAY);
+	clk_disable(siic->clk);
+	return 0;
+}
+
+static const struct dev_pm_ops i2c_sirfsoc_pm_ops = {
+	.suspend = i2c_sirfsoc_suspend,
+	.resume = i2c_sirfsoc_resume,
+};
+#endif
+
+static const struct of_device_id sirfsoc_i2c_of_match[] __devinitconst = {
+	{ .compatible = "sirf,prima2-i2c", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sirfsoc_i2c_of_match);
+
+static struct platform_driver i2c_sirfsoc_driver = {
+	.driver = {
+		.name = "sirfsoc_i2c",
+		.owner = THIS_MODULE,
+#ifdef CONFIG_PM
+		.pm = &i2c_sirfsoc_pm_ops,
+#endif
+		.of_match_table = sirfsoc_i2c_of_match,
+	},
+	.probe = i2c_sirfsoc_probe,
+	.remove = __devexit_p(i2c_sirfsoc_remove),
+};
+module_platform_driver(i2c_sirfsoc_driver);
+
+MODULE_DESCRIPTION("SiRF SoC I2C master controller driver");
+MODULE_AUTHOR("Zhiwu Song <Zhiwu.Song@csr.com>, "
+	"Xiangzhen Ye <Xiangzhen.Ye@csr.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 0ab4a9548745..e978635e60f0 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -457,7 +457,6 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 	int ret;
 
 	tegra_i2c_flush_fifos(i2c_dev);
-	i2c_writel(i2c_dev, 0xFF, I2C_INT_STATUS);
 
 	if (msg->len == 0)
 		return -EINVAL;
diff --git a/drivers/i2c/busses/i2c-versatile.c b/drivers/i2c/busses/i2c-versatile.c
index 60556012312f..f585aead50cc 100644
--- a/drivers/i2c/busses/i2c-versatile.c
+++ b/drivers/i2c/busses/i2c-versatile.c
@@ -16,6 +16,7 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/io.h>
+#include <linux/of_i2c.h>
 
 #define I2C_CONTROL	0x00
 #define I2C_CONTROLS	0x00
@@ -99,6 +100,7 @@ static int i2c_versatile_probe(struct platform_device *dev)
 	strlcpy(i2c->adap.name, "Versatile I2C adapter", sizeof(i2c->adap.name));
 	i2c->adap.algo_data = &i2c->algo;
 	i2c->adap.dev.parent = &dev->dev;
+	i2c->adap.dev.of_node = dev->dev.of_node;
 	i2c->algo = i2c_versatile_algo;
 	i2c->algo.data = i2c;
 
@@ -111,6 +113,7 @@ static int i2c_versatile_probe(struct platform_device *dev)
 		ret = i2c_bit_add_bus(&i2c->adap);
 	if (ret >= 0) {
 		platform_set_drvdata(dev, i2c);
+		of_i2c_register_devices(&i2c->adap);
 		return 0;
 	}
 
@@ -133,12 +136,19 @@ static int i2c_versatile_remove(struct platform_device *dev)
 	return 0;
 }
 
+static const struct of_device_id i2c_versatile_match[] = {
+	{ .compatible = "arm,versatile-i2c", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, i2c_versatile_match);
+
 static struct platform_driver i2c_versatile_driver = {
 	.probe		= i2c_versatile_probe,
 	.remove		= i2c_versatile_remove,
 	.driver		= {
 		.name	= "versatile-i2c",
 		.owner	= THIS_MODULE,
+		.of_match_table = i2c_versatile_match,
 	},
 };
 
diff --git a/drivers/i2c/busses/i2c-xlr.c b/drivers/i2c/busses/i2c-xlr.c
new file mode 100644
index 000000000000..96d3fabd8883
--- /dev/null
+++ b/drivers/i2c/busses/i2c-xlr.c
@@ -0,0 +1,278 @@
+/*
+ * Copyright 2011, Netlogic Microsystems Inc.
+ * Copyright 2004, Matt Porter <mporter@kernel.crashing.org>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+
+/* XLR I2C REGISTERS */
+#define XLR_I2C_CFG		0x00
+#define XLR_I2C_CLKDIV		0x01
+#define XLR_I2C_DEVADDR		0x02
+#define XLR_I2C_ADDR		0x03
+#define XLR_I2C_DATAOUT		0x04
+#define XLR_I2C_DATAIN		0x05
+#define XLR_I2C_STATUS		0x06
+#define XLR_I2C_STARTXFR	0x07
+#define XLR_I2C_BYTECNT		0x08
+#define XLR_I2C_HDSTATIM	0x09
+
+/* XLR I2C REGISTERS FLAGS */
+#define XLR_I2C_BUS_BUSY	0x01
+#define XLR_I2C_SDOEMPTY	0x02
+#define XLR_I2C_RXRDY		0x04
+#define XLR_I2C_ACK_ERR		0x08
+#define XLR_I2C_ARB_STARTERR	0x30
+
+/* Register Values */
+#define XLR_I2C_CFG_ADDR	0xF8
+#define XLR_I2C_CFG_NOADDR	0xFA
+#define XLR_I2C_STARTXFR_ND	0x02    /* No Data */
+#define XLR_I2C_STARTXFR_RD	0x01    /* Read */
+#define XLR_I2C_STARTXFR_WR	0x00    /* Write */
+
+#define XLR_I2C_TIMEOUT		10	/* timeout per byte in msec */
+
+/*
+ * On XLR/XLS, we need to use __raw_ IO to read the I2C registers
+ * because they are in the big-endian MMIO area on the SoC.
+ *
+ * The readl/writel implementation on XLR/XLS byteswaps, because
+ * those are for its little-endian PCI space (see arch/mips/Kconfig).
+ */
+static inline void xlr_i2c_wreg(u32 __iomem *base, unsigned int reg, u32 val)
+{
+	__raw_writel(val, base + reg);
+}
+
+static inline u32 xlr_i2c_rdreg(u32 __iomem *base, unsigned int reg)
+{
+	return __raw_readl(base + reg);
+}
+
+struct xlr_i2c_private {
+	struct i2c_adapter adap;
+	u32 __iomem *iobase;
+};
+
+static int xlr_i2c_tx(struct xlr_i2c_private *priv,  u16 len,
+	u8 *buf, u16 addr)
+{
+	struct i2c_adapter *adap = &priv->adap;
+	unsigned long timeout, stoptime, checktime;
+	u32 i2c_status;
+	int pos, timedout;
+	u8 offset, byte;
+
+	offset = buf[0];
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_ADDR, offset);
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_DEVADDR, addr);
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG, XLR_I2C_CFG_ADDR);
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 1);
+
+	timeout = msecs_to_jiffies(XLR_I2C_TIMEOUT);
+	stoptime = jiffies + timeout;
+	timedout = 0;
+	pos = 1;
+retry:
+	if (len == 1) {
+		xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR,
+				XLR_I2C_STARTXFR_ND);
+	} else {
+		xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, buf[pos]);
+		xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR,
+				XLR_I2C_STARTXFR_WR);
+	}
+
+	while (!timedout) {
+		checktime = jiffies;
+		i2c_status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS);
+
+		if (i2c_status & XLR_I2C_SDOEMPTY) {
+			pos++;
+			/* need to do a empty dataout after the last byte */
+			byte = (pos < len) ? buf[pos] : 0;
+			xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, byte);
+
+			/* reset timeout on successful xmit */
+			stoptime = jiffies + timeout;
+		}
+		timedout = time_after(checktime, stoptime);
+
+		if (i2c_status & XLR_I2C_ARB_STARTERR) {
+			if (timedout)
+				break;
+			goto retry;
+		}
+
+		if (i2c_status & XLR_I2C_ACK_ERR)
+			return -EIO;
+
+		if ((i2c_status & XLR_I2C_BUS_BUSY) == 0 && pos >= len)
+			return 0;
+	}
+	dev_err(&adap->dev, "I2C transmit timeout\n");
+	return -ETIMEDOUT;
+}
+
+static int xlr_i2c_rx(struct xlr_i2c_private *priv, u16 len, u8 *buf, u16 addr)
+{
+	struct i2c_adapter *adap = &priv->adap;
+	u32 i2c_status;
+	unsigned long timeout, stoptime, checktime;
+	int nbytes, timedout;
+	u8 byte;
+
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG, XLR_I2C_CFG_NOADDR);
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len);
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_DEVADDR, addr);
+
+	timeout = msecs_to_jiffies(XLR_I2C_TIMEOUT);
+	stoptime = jiffies + timeout;
+	timedout = 0;
+	nbytes = 0;
+retry:
+	xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR, XLR_I2C_STARTXFR_RD);
+
+	while (!timedout) {
+		checktime = jiffies;
+		i2c_status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS);
+		if (i2c_status & XLR_I2C_RXRDY) {
+			if (nbytes > len)
+				return -EIO;	/* should not happen */
+
+			/* we need to do a dummy datain when nbytes == len */
+			byte = xlr_i2c_rdreg(priv->iobase, XLR_I2C_DATAIN);
+			if (nbytes < len)
+				buf[nbytes] = byte;
+			nbytes++;
+
+			/* reset timeout on successful read */
+			stoptime = jiffies + timeout;
+		}
+
+		timedout = time_after(checktime, stoptime);
+		if (i2c_status & XLR_I2C_ARB_STARTERR) {
+			if (timedout)
+				break;
+			goto retry;
+		}
+
+		if (i2c_status & XLR_I2C_ACK_ERR)
+			return -EIO;
+
+		if ((i2c_status & XLR_I2C_BUS_BUSY) == 0)
+			return 0;
+	}
+
+	dev_err(&adap->dev, "I2C receive timeout\n");
+	return -ETIMEDOUT;
+}
+
+static int xlr_i2c_xfer(struct i2c_adapter *adap,
+	struct i2c_msg *msgs, int num)
+{
+	struct i2c_msg *msg;
+	int i;
+	int ret = 0;
+	struct xlr_i2c_private *priv = i2c_get_adapdata(adap);
+
+	for (i = 0; ret == 0 && i < num; i++) {
+		msg = &msgs[i];
+		if (msg->flags & I2C_M_RD)
+			ret = xlr_i2c_rx(priv, msg->len, &msg->buf[0],
+					msg->addr);
+		else
+			ret = xlr_i2c_tx(priv, msg->len, &msg->buf[0],
+					msg->addr);
+	}
+
+	return (ret != 0) ? ret : num;
+}
+
+static u32 xlr_func(struct i2c_adapter *adap)
+{
+	/* Emulate SMBUS over I2C */
+	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
+}
+
+static struct i2c_algorithm xlr_i2c_algo = {
+	.master_xfer	= xlr_i2c_xfer,
+	.functionality	= xlr_func,
+};
+
+static int __devinit xlr_i2c_probe(struct platform_device *pdev)
+{
+	struct xlr_i2c_private  *priv;
+	struct resource *res;
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->iobase = devm_request_and_ioremap(&pdev->dev, res);
+	if (!priv->iobase) {
+		dev_err(&pdev->dev, "devm_request_and_ioremap failed\n");
+		return -EBUSY;
+	}
+
+	priv->adap.dev.parent = &pdev->dev;
+	priv->adap.owner	= THIS_MODULE;
+	priv->adap.algo_data	= priv;
+	priv->adap.algo		= &xlr_i2c_algo;
+	priv->adap.nr		= pdev->id;
+	priv->adap.class	= I2C_CLASS_HWMON;
+	snprintf(priv->adap.name, sizeof(priv->adap.name), "xlr-i2c");
+
+	i2c_set_adapdata(&priv->adap, priv);
+	ret = i2c_add_numbered_adapter(&priv->adap);
+	if (ret < 0) {
+		dev_err(&priv->adap.dev, "Failed to add i2c bus.\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, priv);
+	dev_info(&priv->adap.dev, "Added I2C Bus.\n");
+	return 0;
+}
+
+static int __devexit xlr_i2c_remove(struct platform_device *pdev)
+{
+	struct xlr_i2c_private *priv;
+
+	priv = platform_get_drvdata(pdev);
+	i2c_del_adapter(&priv->adap);
+	platform_set_drvdata(pdev, NULL);
+	return 0;
+}
+
+static struct platform_driver xlr_i2c_driver = {
+	.probe  = xlr_i2c_probe,
+	.remove = __devexit_p(xlr_i2c_remove),
+	.driver = {
+		.name   = "xlr-i2cbus",
+		.owner  = THIS_MODULE,
+	},
+};
+
+module_platform_driver(xlr_i2c_driver);
+
+MODULE_AUTHOR("Ganesan Ramalingam <ganesanr@netlogicmicro.com>");
+MODULE_DESCRIPTION("XLR/XLS SoC I2C Controller driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:xlr-i2cbus");
diff --git a/include/linux/i2c/at24.h b/include/linux/i2c/at24.h
index 8ace93024d60..285025a9cdc9 100644
--- a/include/linux/i2c/at24.h
+++ b/include/linux/i2c/at24.h
@@ -1,19 +1,42 @@
+/*
+ * at24.h - platform_data for the at24 (generic eeprom) driver
+ * (C) Copyright 2008 by Pengutronix
+ * (C) Copyright 2012 by Wolfram Sang
+ * same license as the driver
+ */
+
 #ifndef _LINUX_AT24_H
 #define _LINUX_AT24_H
 
 #include <linux/types.h>
 #include <linux/memory.h>
 
-/*
- * As seen through Linux I2C, differences between the most common types of I2C
- * memory include:
- * - How much memory is available (usually specified in bit)?
- * - What write page size does it support?
- * - Special flags (16 bit addresses, read_only, world readable...)?
+/**
+ * struct at24_platform_data - data to set up at24 (generic eeprom) driver
+ * @byte_len: size of eeprom in byte
+ * @page_size: number of byte which can be written in one go
+ * @flags: tunable options, check AT24_FLAG_* defines
+ * @setup: an optional callback invoked after eeprom is probed; enables kernel
+	code to access eeprom via memory_accessor, see example
+ * @context: optional parameter passed to setup()
  *
  * If you set up a custom eeprom type, please double-check the parameters.
  * Especially page_size needs extra care, as you risk data loss if your value
  * is bigger than what the chip actually supports!
+ *
+ * An example in pseudo code for a setup() callback:
+ *
+ * void get_mac_addr(struct memory_accessor *mem_acc, void *context)
+ * {
+ * 	u8 *mac_addr = ethernet_pdata->mac_addr;
+ *	off_t offset = context;
+ *
+ *	// Read MAC addr from EEPROM
+ *	if (mem_acc->read(mem_acc, mac_addr, offset, ETH_ALEN) == ETH_ALEN)
+ *		pr_info("Read MAC addr from EEPROM: %pM\n", mac_addr);
+ * }
+ *
+ * This function pointer and context can now be set up in at24_platform_data.
  */
 
 struct at24_platform_data {