Merge branch 'for-linus/i2c' of git://git.fluff.org/bjdooks/linux

* 'for-linus/i2c' of git://git.fluff.org/bjdooks/linux:
i2c: Add support for Xilinx XPS IIC Bus Interface
i2c: omap: Add support for 16-bit registers
i2c-pnx: fix setting start/stop condition
powerpc: doc/dts-bindings: update doc of FSL I2C bindings
i2c-mpc: add support for the MPC512x processors from Freescale
i2c-mpc: rename "setclock" initialization functions to "setup"
i2c-mpc: use __devinit[data] for initialization functions and data
i2c/imx: don't add probe function to the driver struct
i2c: Add support for Ux500/Nomadik I2C controller

Documentation/powerpc/dts-bindings/fsl/i2c.txt

···
 
 Required properties :
 
- - device_type : Should be "i2c"
  - reg : Offset and length of the register set for the device
+ - compatible : should be "fsl,CHIP-i2c" where CHIP is the name of a
+   compatible processor, e.g. mpc8313, mpc8543, mpc8544, mpc5121,
+   mpc5200 or mpc5200b. For the mpc5121, an additional node
+   "fsl,mpc5121-i2c-ctrl" is required as shown in the example below.
 
 Recommended properties :
 
- - compatible : compatibility list with 2 entries, the first should
-   be "fsl,CHIP-i2c" where CHIP is the name of a compatible processor,
-   e.g. mpc8313, mpc8543, mpc8544, mpc5200 or mpc5200b. The second one
-   should be "fsl-i2c".
  - interrupts : <a b> where a is the interrupt number and b is a
    field that represents an encoding of the sense and level
    information for the interrupt.  This should be encoded based on
···
 
 Examples :
 
+	/* MPC5121 based board */
+	i2c@1740 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "fsl,mpc5121-i2c", "fsl-i2c";
+		reg = <0x1740 0x20>;
+		interrupts = <11 0x8>;
+		interrupt-parent = <&ipic>;
+		clock-frequency = <100000>;
+	};
+
+	i2ccontrol@1760 {
+		compatible = "fsl,mpc5121-i2c-ctrl";
+		reg = <0x1760 0x8>;
+	};
+
+	/* MPC5200B based board */
 	i2c@3d00 {
 		#address-cells = <1>;
 		#size-cells = <0>;
 		compatible = "fsl,mpc5200b-i2c","fsl,mpc5200-i2c","fsl-i2c";
-		cell-index = <0>;
 		reg = <0x3d00 0x40>;
 		interrupts = <2 15 0>;
 		interrupt-parent = <&mpc5200_pic>;
 		fsl,preserve-clocking;
 	};
 
+	/* MPC8544 base board */
 	i2c@3100 {
 		#address-cells = <1>;
 		#size-cells = <0>;
-		cell-index = <1>;
 		compatible = "fsl,mpc8544-i2c", "fsl-i2c";
 		reg = <0x3100 0x100>;
 		interrupts = <43 2>;
 		interrupt-parent = <&mpic>;
 		clock-frequency = <400000>;
 	};
-

drivers/i2c/busses/Kconfig

···
 	  instead.
 
 config I2C_MPC
-	tristate "MPC107/824x/85xx/52xx/86xx"
+	tristate "MPC107/824x/85xx/512x/52xx/83xx/86xx"
 	depends on PPC32
 	help
 	  If you say yes to this option, support will be included for the
-	  built-in I2C interface on the MPC107/Tsi107/MPC8240/MPC8245 and
-	  MPC85xx/MPC8641 family processors. The driver may also work on 52xx
-	  family processors, though interrupts are known not to work.
+	  built-in I2C interface on the MPC107, Tsi107, MPC512x, MPC52xx,
+	  MPC8240, MPC8245, MPC83xx, MPC85xx and MPC8641 family processors.
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-mpc.
···
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-mv64xxx.
+
+config I2C_NOMADIK
+	tristate "ST-Ericsson Nomadik/Ux500 I2C Controller"
+	depends on PLAT_NOMADIK
+	help
+	  If you say yes to this option, support will be included for the
+	  I2C interface from ST-Ericsson's Nomadik and Ux500 architectures.
 
 config I2C_OCORES
 	tristate "OpenCores I2C Controller"
···
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-octeon.
+
+config I2C_XILINX
+	tristate "Xilinx I2C Controller"
+	depends on EXPERIMENTAL && HAS_IOMEM
+	help
+	  If you say yes to this option, support will be included for the
+	  Xilinx I2C controller.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called xilinx_i2c.
 
 comment "External I2C/SMBus adapter drivers"
 

drivers/i2c/busses/Makefile

···
 obj-$(CONFIG_I2C_IXP2000)	+= i2c-ixp2000.o
 obj-$(CONFIG_I2C_MPC)		+= i2c-mpc.o
 obj-$(CONFIG_I2C_MV64XXX)	+= i2c-mv64xxx.o
+obj-$(CONFIG_I2C_NOMADIK)	+= i2c-nomadik.o
 obj-$(CONFIG_I2C_OCORES)	+= i2c-ocores.o
 obj-$(CONFIG_I2C_OMAP)		+= i2c-omap.o
 obj-$(CONFIG_I2C_PASEMI)	+= i2c-pasemi.o
···
 obj-$(CONFIG_I2C_STU300)	+= i2c-stu300.o
 obj-$(CONFIG_I2C_VERSATILE)	+= i2c-versatile.o
 obj-$(CONFIG_I2C_OCTEON)	+= i2c-octeon.o
+obj-$(CONFIG_I2C_XILINX)	+= i2c-xiic.o
 
 # External I2C/SMBus adapter drivers
 obj-$(CONFIG_I2C_PARPORT)	+= i2c-parport.o

drivers/i2c/busses/i2c-imx.c

···
 }
 
 static struct platform_driver i2c_imx_driver = {
-	.probe		= i2c_imx_probe,
 	.remove		= __exit_p(i2c_imx_remove),
 	.driver	= {
 		.name	= DRIVER_NAME,

drivers/i2c/busses/i2c-mpc.c

···
 
 #define DRV_NAME "mpc-i2c"
 
+#define MPC_I2C_CLOCK_LEGACY   0
+#define MPC_I2C_CLOCK_PRESERVE (~0U)
+
 #define MPC_I2C_FDR   0x04
 #define MPC_I2C_CR    0x08
 #define MPC_I2C_SR    0x0c
···
 	u16 fdr;	/* including dfsrr */
 };
 
-struct mpc_i2c_match_data {
-	void (*setclock)(struct device_node *node,
-			 struct mpc_i2c *i2c,
-			 u32 clock, u32 prescaler);
+struct mpc_i2c_data {
+	void (*setup)(struct device_node *node, struct mpc_i2c *i2c,
+		      u32 clock, u32 prescaler);
 	u32 prescaler;
 };
 
···
 	return 0;
 }
 
-#ifdef CONFIG_PPC_MPC52xx
-static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
+#if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
+static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] __devinitconst = {
 	{20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
 	{28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02},
 	{36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28},
···
 	{10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f}
 };
 
-int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock, int prescaler)
+static int __devinit mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
+					  int prescaler)
 {
 	const struct mpc_i2c_divider *div = NULL;
 	unsigned int pvr = mfspr(SPRN_PVR);
 	u32 divider;
 	int i;
 
-	if (!clock)
+	if (clock == MPC_I2C_CLOCK_LEGACY)
 		return -EINVAL;
 
 	/* Determine divider value */
···
 	return div ? (int)div->fdr : -EINVAL;
 }
 
-static void mpc_i2c_setclock_52xx(struct device_node *node,
-				  struct mpc_i2c *i2c,
-				  u32 clock, u32 prescaler)
+static void __devinit mpc_i2c_setup_52xx(struct device_node *node,
+					 struct mpc_i2c *i2c,
+					 u32 clock, u32 prescaler)
 {
 	int ret, fdr;
+
+	if (clock == MPC_I2C_CLOCK_PRESERVE) {
+		dev_dbg(i2c->dev, "using fdr %d\n",
+			readb(i2c->base + MPC_I2C_FDR));
+		return;
+	}
 
 	ret = mpc_i2c_get_fdr_52xx(node, clock, prescaler);
 	fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
···
 	if (ret >= 0)
 		dev_info(i2c->dev, "clock %d Hz (fdr=%d)\n", clock, fdr);
 }
-#else /* !CONFIG_PPC_MPC52xx */
-static void mpc_i2c_setclock_52xx(struct device_node *node,
-				  struct mpc_i2c *i2c,
-				  u32 clock, u32 prescaler)
+#else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
+static void __devinit mpc_i2c_setup_52xx(struct device_node *node,
+					 struct mpc_i2c *i2c,
+					 u32 clock, u32 prescaler)
 {
 }
-#endif /* CONFIG_PPC_MPC52xx*/
+#endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
+
+#ifdef CONFIG_PPC_MPC512x
+static void __devinit mpc_i2c_setup_512x(struct device_node *node,
+					 struct mpc_i2c *i2c,
+					 u32 clock, u32 prescaler)
+{
+	struct device_node *node_ctrl;
+	void __iomem *ctrl;
+	const u32 *pval;
+	u32 idx;
+
+	/* Enable I2C interrupts for mpc5121 */
+	node_ctrl = of_find_compatible_node(NULL, NULL,
+					    "fsl,mpc5121-i2c-ctrl");
+	if (node_ctrl) {
+		ctrl = of_iomap(node_ctrl, 0);
+		if (ctrl) {
+			/* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
+			pval = of_get_property(node, "reg", NULL);
+			idx = (*pval & 0xff) / 0x20;
+			setbits32(ctrl, 1 << (24 + idx * 2));
+			iounmap(ctrl);
+		}
+		of_node_put(node_ctrl);
+	}
+
+	/* The clock setup for the 52xx works also fine for the 512x */
+	mpc_i2c_setup_52xx(node, i2c, clock, prescaler);
+}
+#else /* CONFIG_PPC_MPC512x */
+static void __devinit mpc_i2c_setup_512x(struct device_node *node,
+					 struct mpc_i2c *i2c,
+					 u32 clock, u32 prescaler)
+{
+}
+#endif /* CONFIG_PPC_MPC512x */
 
 #ifdef CONFIG_FSL_SOC
-static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = {
+static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] __devinitconst = {
 	{160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123},
 	{288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102},
 	{416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127},
···
 	{49152, 0x011e}, {61440, 0x011f}
 };
 
-u32 mpc_i2c_get_sec_cfg_8xxx(void)
+static u32 __devinit mpc_i2c_get_sec_cfg_8xxx(void)
 {
 	struct device_node *node = NULL;
 	u32 __iomem *reg;
···
 	return val;
 }
 
-int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock, u32 prescaler)
+static int __devinit mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
+					  u32 prescaler)
 {
 	const struct mpc_i2c_divider *div = NULL;
 	u32 divider;
 	int i;
 
-	if (!clock)
+	if (clock == MPC_I2C_CLOCK_LEGACY)
 		return -EINVAL;
 
 	/* Determine proper divider value */
···
 	return div ? (int)div->fdr : -EINVAL;
 }
 
-static void mpc_i2c_setclock_8xxx(struct device_node *node,
-				  struct mpc_i2c *i2c,
-				  u32 clock, u32 prescaler)
+static void __devinit mpc_i2c_setup_8xxx(struct device_node *node,
+					 struct mpc_i2c *i2c,
+					 u32 clock, u32 prescaler)
 {
 	int ret, fdr;
+
+	if (clock == MPC_I2C_CLOCK_PRESERVE) {
+		dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
+			readb(i2c->base + MPC_I2C_DFSRR),
+			readb(i2c->base + MPC_I2C_FDR));
+		return;
+	}
 
 	ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler);
 	fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
···
 }
 
 #else /* !CONFIG_FSL_SOC */
-static void mpc_i2c_setclock_8xxx(struct device_node *node,
-				  struct mpc_i2c *i2c,
-				  u32 clock, u32 prescaler)
+static void __devinit mpc_i2c_setup_8xxx(struct device_node *node,
+					 struct mpc_i2c *i2c,
+					 u32 clock, u32 prescaler)
 {
 }
 #endif /* CONFIG_FSL_SOC */
···
 {
 	struct mpc_i2c *i2c;
 	const u32 *prop;
-	u32 clock = 0;
+	u32 clock = MPC_I2C_CLOCK_LEGACY;
 	int result = 0;
 	int plen;
 
···
 		}
 	}
 
-	if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) {
+	if (of_get_property(op->node, "fsl,preserve-clocking", NULL)) {
+		clock = MPC_I2C_CLOCK_PRESERVE;
+	} else {
 		prop = of_get_property(op->node, "clock-frequency", &plen);
 		if (prop && plen == sizeof(u32))
 			clock = *prop;
+	}
 
-		if (match->data) {
-			struct mpc_i2c_match_data *data =
-				(struct mpc_i2c_match_data *)match->data;
-			data->setclock(op->node, i2c, clock, data->prescaler);
-		} else {
-			/* Backwards compatibility */
-			if (of_get_property(op->node, "dfsrr", NULL))
-				mpc_i2c_setclock_8xxx(op->node, i2c,
-						      clock, 0);
-		}
+	if (match->data) {
+		struct mpc_i2c_data *data = match->data;
+		data->setup(op->node, i2c, clock, data->prescaler);
+	} else {
+		/* Backwards compatibility */
+		if (of_get_property(op->node, "dfsrr", NULL))
+			mpc_i2c_setup_8xxx(op->node, i2c, clock, 0);
 	}
 
 	dev_set_drvdata(&op->dev, i2c);
···
 	return 0;
 };
 
+static struct mpc_i2c_data mpc_i2c_data_512x __devinitdata = {
+	.setup = mpc_i2c_setup_512x,
+};
+
+static struct mpc_i2c_data mpc_i2c_data_52xx __devinitdata = {
+	.setup = mpc_i2c_setup_52xx,
+};
+
+static struct mpc_i2c_data mpc_i2c_data_8313 __devinitdata = {
+	.setup = mpc_i2c_setup_8xxx,
+};
+
+static struct mpc_i2c_data mpc_i2c_data_8543 __devinitdata = {
+	.setup = mpc_i2c_setup_8xxx,
+	.prescaler = 2,
+};
+
+static struct mpc_i2c_data mpc_i2c_data_8544 __devinitdata = {
+	.setup = mpc_i2c_setup_8xxx,
+	.prescaler = 3,
+};
+
 static const struct of_device_id mpc_i2c_of_match[] = {
-	{.compatible = "mpc5200-i2c",
-	 .data = &(struct mpc_i2c_match_data) {
-			.setclock = mpc_i2c_setclock_52xx,
-		},
-	},
-	{.compatible = "fsl,mpc5200b-i2c",
-	 .data = &(struct mpc_i2c_match_data) {
-			.setclock = mpc_i2c_setclock_52xx,
-		},
-	},
-	{.compatible = "fsl,mpc5200-i2c",
-	 .data = &(struct mpc_i2c_match_data) {
-			.setclock = mpc_i2c_setclock_52xx,
-		},
-	},
-	{.compatible = "fsl,mpc8313-i2c",
-	 .data = &(struct mpc_i2c_match_data) {
-			.setclock = mpc_i2c_setclock_8xxx,
-		},
-	},
-	{.compatible = "fsl,mpc8543-i2c",
-	 .data = &(struct mpc_i2c_match_data) {
-			.setclock = mpc_i2c_setclock_8xxx,
-			.prescaler = 2,
-		},
-	},
-	{.compatible = "fsl,mpc8544-i2c",
-	 .data = &(struct mpc_i2c_match_data) {
-			.setclock = mpc_i2c_setclock_8xxx,
-			.prescaler = 3,
-		},
+	{.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
+	{.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
+	{.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
+	{.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
+	{.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
+	{.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
+	{.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
 	/* Backward compatibility */
-	},
 	{.compatible = "fsl-i2c", },
 	{},
 };
-
 MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
-
 
 /* Structure for a device driver */
 static struct of_platform_driver mpc_i2c_driver = {
···
 
 MODULE_AUTHOR("Adrian Cox <[e-mail]>");
 MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
-		   "MPC824x/85xx/52xx processors");
+		   "MPC824x/83xx/85xx/86xx/512x/52xx processors");
 MODULE_LICENSE("GPL");

drivers/i2c/busses/i2c-nomadik.c

···
+/*
+ * Copyright (C) 2009 ST-Ericsson
+ * Copyright (C) 2009 STMicroelectronics
+ *
+ * I2C master mode controller driver, used in Nomadik 8815
+ * and Ux500 platforms.
+ *
+ * Author: Srinidhi Kasagar <[e-mail]>
+ * Author: Sachin Verma <[e-mail]>
+ *
+ * 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.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <plat/i2c.h>
+
+#define DRIVER_NAME "nmk-i2c"
+
+/* I2C Controller register offsets */
+#define I2C_CR		(0x000)
+#define I2C_SCR		(0x004)
+#define I2C_HSMCR	(0x008)
+#define I2C_MCR		(0x00C)
+#define I2C_TFR		(0x010)
+#define I2C_SR		(0x014)
+#define I2C_RFR		(0x018)
+#define I2C_TFTR	(0x01C)
+#define I2C_RFTR	(0x020)
+#define I2C_DMAR	(0x024)
+#define I2C_BRCR	(0x028)
+#define I2C_IMSCR	(0x02C)
+#define I2C_RISR	(0x030)
+#define I2C_MISR	(0x034)
+#define I2C_ICR		(0x038)
+
+/* Control registers */
+#define I2C_CR_PE		(0x1 << 0)	/* Peripheral Enable */
+#define I2C_CR_OM		(0x3 << 1)	/* Operating mode */
+#define I2C_CR_SAM		(0x1 << 3)	/* Slave addressing mode */
+#define I2C_CR_SM		(0x3 << 4)	/* Speed mode */
+#define I2C_CR_SGCM		(0x1 << 6)	/* Slave general call mode */
+#define I2C_CR_FTX		(0x1 << 7)	/* Flush Transmit */
+#define I2C_CR_FRX		(0x1 << 8)	/* Flush Receive */
+#define I2C_CR_DMA_TX_EN	(0x1 << 9)	/* DMA Tx enable */
+#define I2C_CR_DMA_RX_EN	(0x1 << 10)	/* DMA Rx Enable */
+#define I2C_CR_DMA_SLE		(0x1 << 11)	/* DMA sync. logic enable */
+#define I2C_CR_LM		(0x1 << 12)	/* Loopback mode */
+#define I2C_CR_FON		(0x3 << 13)	/* Filtering on */
+#define I2C_CR_FS		(0x3 << 15)	/* Force stop enable */
+
+/* Master controller (MCR) register */
+#define I2C_MCR_OP		(0x1 << 0)	/* Operation */
+#define I2C_MCR_A7		(0x7f << 1)	/* 7-bit address */
+#define I2C_MCR_EA10		(0x7 << 8) 	/* 10-bit Extended address */
+#define I2C_MCR_SB		(0x1 << 11)	/* Extended address */
+#define I2C_MCR_AM		(0x3 << 12)	/* Address type */
+#define I2C_MCR_STOP		(0x1 << 14) 	/* Stop condition */
+#define I2C_MCR_LENGTH		(0x7ff << 15) 	/* Transaction length */
+
+/* Status register (SR) */
+#define I2C_SR_OP		(0x3 << 0)	/* Operation */
+#define I2C_SR_STATUS		(0x3 << 2)	/* controller status */
+#define I2C_SR_CAUSE		(0x7 << 4)	/* Abort cause */
+#define I2C_SR_TYPE		(0x3 << 7)	/* Receive type */
+#define I2C_SR_LENGTH		(0x7ff << 9)	/* Transfer length */
+
+/* Interrupt mask set/clear (IMSCR) bits */
+#define I2C_IT_TXFE 		(0x1 << 0)
+#define I2C_IT_TXFNE		(0x1 << 1)
+#define I2C_IT_TXFF		(0x1 << 2)
+#define I2C_IT_TXFOVR		(0x1 << 3)
+#define I2C_IT_RXFE		(0x1 << 4)
+#define I2C_IT_RXFNF		(0x1 << 5)
+#define I2C_IT_RXFF		(0x1 << 6)
+#define I2C_IT_RFSR		(0x1 << 16)
+#define I2C_IT_RFSE		(0x1 << 17)
+#define I2C_IT_WTSR		(0x1 << 18)
+#define I2C_IT_MTD		(0x1 << 19)
+#define I2C_IT_STD		(0x1 << 20)
+#define I2C_IT_MAL		(0x1 << 24)
+#define I2C_IT_BERR		(0x1 << 25)
+#define I2C_IT_MTDWS		(0x1 << 28)
+
+#define GEN_MASK(val, mask, sb)  (((val) << (sb)) & (mask))
+
+/* some bits in ICR are reserved */
+#define I2C_CLEAR_ALL_INTS	0x131f007f
+
+/* first three msb bits are reserved */
+#define IRQ_MASK(mask)		(mask & 0x1fffffff)
+
+/* maximum threshold value */
+#define MAX_I2C_FIFO_THRESHOLD	15
+
+enum i2c_status {
+	I2C_NOP,
+	I2C_ON_GOING,
+	I2C_OK,
+	I2C_ABORT
+};
+
+/* operation */
+enum i2c_operation {
+	I2C_NO_OPERATION = 0xff,
+	I2C_WRITE = 0x00,
+	I2C_READ = 0x01
+};
+
+/* controller response timeout in ms */
+#define I2C_TIMEOUT_MS	500
+
+/**
+ * struct i2c_nmk_client - client specific data
+ * @slave_adr: 7-bit slave address
+ * @count: no. bytes to be transfered
+ * @buffer: client data buffer
+ * @xfer_bytes: bytes transfered till now
+ * @operation: current I2C operation
+ */
+struct i2c_nmk_client {
+	unsigned short		slave_adr;
+	unsigned long		count;
+	unsigned char		*buffer;
+	unsigned long		xfer_bytes;
+	enum i2c_operation	operation;
+};
+
+/**
+ * struct nmk_i2c_dev - private data structure of the controller
+ * @pdev: parent platform device
+ * @adap: corresponding I2C adapter
+ * @irq: interrupt line for the controller
+ * @virtbase: virtual io memory area
+ * @clk: hardware i2c block clock
+ * @cfg: machine provided controller configuration
+ * @cli: holder of client specific data
+ * @stop: stop condition
+ * @xfer_complete: acknowledge completion for a I2C message
+ * @result: controller propogated result
+ */
+struct nmk_i2c_dev {
+	struct platform_device		*pdev;
+	struct i2c_adapter 		adap;
+	int 				irq;
+	void __iomem			*virtbase;
+	struct clk			*clk;
+	struct nmk_i2c_controller	cfg;
+	struct i2c_nmk_client		cli;
+	int 				stop;
+	struct completion		xfer_complete;
+	int 				result;
+};
+
+/* controller's abort causes */
+static const char *abort_causes[] = {
+	"no ack received after address transmission",
+	"no ack received during data phase",
+	"ack received after xmission of master code",
+	"master lost arbitration",
+	"slave restarts",
+	"slave reset",
+	"overflow, maxsize is 2047 bytes",
+};
+
+static inline void i2c_set_bit(void __iomem *reg, u32 mask)
+{
+	writel(readl(reg) | mask, reg);
+}
+
+static inline void i2c_clr_bit(void __iomem *reg, u32 mask)
+{
+	writel(readl(reg) & ~mask, reg);
+}
+
+/**
+ * flush_i2c_fifo() - This function flushes the I2C FIFO
+ * @dev: private data of I2C Driver
+ *
+ * This function flushes the I2C Tx and Rx FIFOs. It returns
+ * 0 on successful flushing of FIFO
+ */
+static int flush_i2c_fifo(struct nmk_i2c_dev *dev)
+{
+#define LOOP_ATTEMPTS 10
+	int i;
+	unsigned long timeout;
+
+	/*
+	 * flush the transmit and receive FIFO. The flushing
+	 * operation takes several cycles before to be completed.
+	 * On the completion, the I2C internal logic clears these
+	 * bits, until then no one must access Tx, Rx FIFO and
+	 * should poll on these bits waiting for the completion.
+	 */
+	writel((I2C_CR_FTX | I2C_CR_FRX), dev->virtbase + I2C_CR);
+
+	for (i = 0; i < LOOP_ATTEMPTS; i++) {
+		timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT_MS);
+
+		while (!time_after(jiffies, timeout)) {
+			if ((readl(dev->virtbase + I2C_CR) &
+				(I2C_CR_FTX | I2C_CR_FRX)) == 0)
+					return 0;
+		}
+	}
+
+	dev_err(&dev->pdev->dev, "flushing operation timed out "
+		"giving up after %d attempts", LOOP_ATTEMPTS);
+
+	return -ETIMEDOUT;
+}
+
+/**
+ * disable_all_interrupts() - Disable all interrupts of this I2c Bus
+ * @dev: private data of I2C Driver
+ */
+static void disable_all_interrupts(struct nmk_i2c_dev *dev)
+{
+	u32 mask = IRQ_MASK(0);
+	writel(mask, dev->virtbase + I2C_IMSCR);
+}
+
+/**
+ * clear_all_interrupts() - Clear all interrupts of I2C Controller
+ * @dev: private data of I2C Driver
+ */
+static void clear_all_interrupts(struct nmk_i2c_dev *dev)
+{
+	u32 mask;
+	mask = IRQ_MASK(I2C_CLEAR_ALL_INTS);
+	writel(mask, dev->virtbase + I2C_ICR);
+}
+
+/**
+ * init_hw() - initialize the I2C hardware
+ * @dev: private data of I2C Driver
+ */
+static int init_hw(struct nmk_i2c_dev *dev)
+{
+	int stat;
+
+	stat = flush_i2c_fifo(dev);
+	if (stat)
+		return stat;
+
+	/* disable the controller */
+	i2c_clr_bit(dev->virtbase + I2C_CR , I2C_CR_PE);
+
+	disable_all_interrupts(dev);
+
+	clear_all_interrupts(dev);
+
+	dev->cli.operation = I2C_NO_OPERATION;
+
+	return 0;
+}
+
+/* enable peripheral, master mode operation */
+#define DEFAULT_I2C_REG_CR 	((1 << 1) | I2C_CR_PE)
+
+/**
+ * load_i2c_mcr_reg() - load the MCR register
+ * @dev: private data of controller
+ */
+static u32 load_i2c_mcr_reg(struct nmk_i2c_dev *dev)
+{
+	u32 mcr = 0;
+
+	/* 7-bit address transaction */
+	mcr |= GEN_MASK(1, I2C_MCR_AM, 12);
+	mcr |= GEN_MASK(dev->cli.slave_adr, I2C_MCR_A7, 1);
+
+	/* start byte procedure not applied */
+	mcr |= GEN_MASK(0, I2C_MCR_SB, 11);
+
+	/* check the operation, master read/write? */
+	if (dev->cli.operation == I2C_WRITE)
+		mcr |= GEN_MASK(I2C_WRITE, I2C_MCR_OP, 0);
+	else
+		mcr |= GEN_MASK(I2C_READ, I2C_MCR_OP, 0);
+
+	/* stop or repeated start? */
+	if (dev->stop)
+		mcr |= GEN_MASK(1, I2C_MCR_STOP, 14);
+	else
+		mcr &= ~(GEN_MASK(1, I2C_MCR_STOP, 14));
+
+	mcr |= GEN_MASK(dev->cli.count, I2C_MCR_LENGTH, 15);
+
+	return mcr;
+}
+
+/**
+ * setup_i2c_controller() - setup the controller
+ * @dev: private data of controller
+ */
+static void setup_i2c_controller(struct nmk_i2c_dev *dev)
+{
+	u32 brcr1, brcr2;
+	u32 i2c_clk, div;
+
+	writel(0x0, dev->virtbase + I2C_CR);
+	writel(0x0, dev->virtbase + I2C_HSMCR);
+	writel(0x0, dev->virtbase + I2C_TFTR);
+	writel(0x0, dev->virtbase + I2C_RFTR);
+	writel(0x0, dev->virtbase + I2C_DMAR);
+
+	/*
+	 * set the slsu:
+	 *
+	 * slsu defines the data setup time after SCL clock
+	 * stretching in terms of i2c clk cycles. The
+	 * needed setup time for the three modes are 250ns,
+	 * 100ns, 10ns repectively thus leading to the values
+	 * of 14, 6, 2 for a 48 MHz i2c clk.
+	 */
+	writel(dev->cfg.slsu << 16, dev->virtbase + I2C_SCR);
+
+	i2c_clk = clk_get_rate(dev->clk);
+
+	/* fallback to std. mode if machine has not provided it */
+	if (dev->cfg.clk_freq == 0)
+		dev->cfg.clk_freq = 100000;
+
+	/*
+	 * The spec says, in case of std. mode the divider is
+	 * 2 whereas it is 3 for fast and fastplus mode of
+	 * operation. TODO - high speed support.
+	 */
+	div = (dev->cfg.clk_freq > 100000) ? 3 : 2;
+
+	/*
+	 * generate the mask for baud rate counters. The controller
+	 * has two baud rate counters. One is used for High speed
+	 * operation, and the other is for std, fast mode, fast mode
+	 * plus operation. Currently we do not supprt high speed mode
+	 * so set brcr1 to 0.
+	 */
+	brcr1 = 0 << 16;
+	brcr2 = (i2c_clk/(dev->cfg.clk_freq * div)) & 0xffff;
+
+	/* set the baud rate counter register */
+	writel((brcr1 | brcr2), dev->virtbase + I2C_BRCR);
+
+	/*
+	 * set the speed mode. Currently we support
+	 * only standard and fast mode of operation
+	 * TODO - support for fast mode plus (upto 1Mb/s)
+	 * and high speed (up to 3.4 Mb/s)
+	 */
+	if (dev->cfg.sm > I2C_FREQ_MODE_FAST) {
+		dev_err(&dev->pdev->dev, "do not support this mode "
+			"defaulting to std. mode\n");
+		brcr2 = i2c_clk/(100000 * 2) & 0xffff;
+		writel((brcr1 | brcr2), dev->virtbase + I2C_BRCR);
+		writel(I2C_FREQ_MODE_STANDARD << 4,
+				dev->virtbase + I2C_CR);
+	}
+	writel(dev->cfg.sm << 4, dev->virtbase + I2C_CR);
+
+	/* set the Tx and Rx FIFO threshold */
+	writel(dev->cfg.tft, dev->virtbase + I2C_TFTR);
+	writel(dev->cfg.rft, dev->virtbase + I2C_RFTR);
+}
+
+/**
+ * read_i2c() - Read from I2C client device
+ * @dev: private data of I2C Driver
+ *
+ * This function reads from i2c client device when controller is in
+ * master mode. There is a completion timeout. If there is no transfer
+ * before timeout error is returned.
+ */
+static int read_i2c(struct nmk_i2c_dev *dev)
+{
+	u32 status = 0;
+	u32 mcr;
+	u32 irq_mask = 0;
+	int timeout;
+
+	mcr = load_i2c_mcr_reg(dev);
+	writel(mcr, dev->virtbase + I2C_MCR);
+
+	/* load the current CR value */
+	writel(readl(dev->virtbase + I2C_CR) | DEFAULT_I2C_REG_CR,
+			dev->virtbase + I2C_CR);
+
+	/* enable the controller */
+	i2c_set_bit(dev->virtbase + I2C_CR, I2C_CR_PE);
+
+	init_completion(&dev->xfer_complete);
+
+	/* enable interrupts by setting the mask */
+	irq_mask = (I2C_IT_RXFNF | I2C_IT_RXFF |
+			I2C_IT_MAL | I2C_IT_BERR);
+
+	if (dev->stop)
+		irq_mask |= I2C_IT_MTD;
+	else
+		irq_mask |= I2C_IT_MTDWS;
+
+	irq_mask = I2C_CLEAR_ALL_INTS & IRQ_MASK(irq_mask);
+
+	writel(readl(dev->virtbase + I2C_IMSCR) | irq_mask,
+			dev->virtbase + I2C_IMSCR);
+
+	timeout = wait_for_completion_interruptible_timeout(
+		&dev->xfer_complete, msecs_to_jiffies(I2C_TIMEOUT_MS));
+
+	if (timeout < 0) {
+		dev_err(&dev->pdev->dev,
+			"wait_for_completion_interruptible_timeout"
+			"returned %d waiting for event\n", timeout);
+		status = timeout;
+	}
+
+	if (timeout == 0) {
+		/* controler has timedout, re-init the h/w */
+		dev_err(&dev->pdev->dev, "controller timed out, re-init h/w\n");
+		(void) init_hw(dev);
+		status = -ETIMEDOUT;
+	}
+
+	return status;
+}
+
+/**
+ * write_i2c() - Write data to I2C client.
+ * @dev: private data of I2C Driver
+ *
+ * This function writes data to I2C client
+ */
+static int write_i2c(struct nmk_i2c_dev *dev)
+{
+	u32 status = 0;
+	u32 mcr;
+	u32 irq_mask = 0;
+	int timeout;
+
+	mcr = load_i2c_mcr_reg(dev);
+
+	writel(mcr, dev->virtbase + I2C_MCR);
+
+	/* load the current CR value */
+	writel(readl(dev->virtbase + I2C_CR) | DEFAULT_I2C_REG_CR,
+			dev->virtbase + I2C_CR);
+
+	/* enable the controller */
+	i2c_set_bit(dev->virtbase + I2C_CR , I2C_CR_PE);
+
+	init_completion(&dev->xfer_complete);
+
+	/* enable interrupts by settings the masks */
+	irq_mask = (I2C_IT_TXFNE | I2C_IT_TXFOVR |
+			I2C_IT_MAL | I2C_IT_BERR);
+
+	/*
+	 * check if we want to transfer a single or multiple bytes, if so
+	 * set the MTDWS bit (Master Transaction Done Without Stop)
+	 * to start repeated start operation
+	 */
+	if (dev->stop)
+		irq_mask |= I2C_IT_MTD;
+	else
+		irq_mask |= I2C_IT_MTDWS;
+
+	irq_mask = I2C_CLEAR_ALL_INTS & IRQ_MASK(irq_mask);
+
+	writel(readl(dev->virtbase + I2C_IMSCR) | irq_mask,
+			dev->virtbase + I2C_IMSCR);
+
+	timeout = wait_for_completion_interruptible_timeout(
+		&dev->xfer_complete, msecs_to_jiffies(I2C_TIMEOUT_MS));
+
+	if (timeout < 0) {
+		dev_err(&dev->pdev->dev,
+			"wait_for_completion_interruptible_timeout"
+			"returned %d waiting for event\n", timeout);
+		status = timeout;
+	}
+
+	if (timeout == 0) {
+		/* controler has timedout, re-init the h/w */
+		dev_err(&dev->pdev->dev, "controller timed out, re-init h/w\n");
+		(void) init_hw(dev);
+		status = -ETIMEDOUT;
+	}
+
+	return status;
+}
+
+/**
+ * nmk_i2c_xfer() - I2C transfer function used by kernel framework
+ * @i2c_adap 	- Adapter pointer to the controller
+ * @msgs[] - Pointer to data to be written.
+ * @num_msgs - Number of messages to be executed
+ *
+ * This is the function called by the generic kernel i2c_transfer()
+ * or i2c_smbus...() API calls. Note that this code is protected by the
+ * semaphore set in the kernel i2c_transfer() function.
+ *
+ * NOTE:
+ * READ TRANSFER : We impose a restriction of the first message to be the
+ * 		index message for any read transaction.
+ * 		- a no index is coded as '0',
+ * 		- 2byte big endian index is coded as '3'
+ * 		!!! msg[0].buf holds the actual index.
+ * 		This is compatible with generic messages of smbus emulator
+ * 		that send a one byte index.
+ * 		eg. a I2C transation to read 2 bytes from index 0
+ *			idx = 0;
+ *			msg[0].addr = client->addr;
+ *			msg[0].flags = 0x0;
+ *			msg[0].len = 1;
+ *			msg[0].buf = &idx;
+ *
+ *			msg[1].addr = client->addr;
+ *			msg[1].flags = I2C_M_RD;
+ *			msg[1].len = 2;
+ *			msg[1].buf = rd_buff
+ *			i2c_transfer(adap, msg, 2);
+ *
+ * WRITE TRANSFER : The I2C standard interface interprets all data as payload.
+ *		If you want to emulate an SMBUS write transaction put the
+ *		index as first byte(or first and second) in the payload.
+ *		eg. a I2C transation to write 2 bytes from index 1
+ *			wr_buff[0] = 0x1;
+ *			wr_buff[1] = 0x23;
+ *			wr_buff[2] = 0x46;
+ *			msg[0].flags = 0x0;
+ *			msg[0].len = 3;
+ *			msg[0].buf = wr_buff;
+ *			i2c_transfer(adap, msg, 1);
+ *
+ * To read or write a block of data (multiple bytes) using SMBUS emulation
+ * please use the i2c_smbus_read_i2c_block_data()
+ * or i2c_smbus_write_i2c_block_data() API
+ */
+static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
+		struct i2c_msg msgs[], int num_msgs)
+{
+	int status;
+	int i;
+	u32 cause;
+	struct nmk_i2c_dev *dev = i2c_get_adapdata(i2c_adap);
+
+	status = init_hw(dev);
+	if (status)
+		return status;
+
+	/* setup the i2c controller */
+	setup_i2c_controller(dev);
+
+	for (i = 0; i < num_msgs; i++) {
+		if (unlikely(msgs[i].flags & I2C_M_TEN)) {
+			dev_err(&dev->pdev->dev, "10 bit addressing"
+					"not supported\n");
+			return -EINVAL;
+		}
+		dev->cli.slave_adr	= msgs[i].addr;
+		dev->cli.buffer		= msgs[i].buf;
+		dev->cli.count		= msgs[i].len;
+		dev->stop = (i < (num_msgs - 1)) ? 0 : 1;
+		dev->result = 0;
+
+		if (msgs[i].flags & I2C_M_RD) {
+			/* it is a read operation */
+			dev->cli.operation = I2C_READ;
+			status = read_i2c(dev);
+		} else {
+			/* write operation */
+			dev->cli.operation = I2C_WRITE;
+			status = write_i2c(dev);
+		}
+		if (status || (dev->result)) {
+			/* get the abort cause */
+			cause =	(readl(dev->virtbase + I2C_SR) >> 4) & 0x7;
+			dev_err(&dev->pdev->dev, "error during I2C"
+					"message xfer: %d\n", cause);
+			dev_err(&dev->pdev->dev, "%s\n",
+				cause >= ARRAY_SIZE(abort_causes)
+				? "unknown reason" : abort_causes[cause]);
+			return status;
+		}
+		mdelay(1);
+	}
+	/* return the no. messages processed */
+	if (status)
+		return status;
+	else
+		return num_msgs;
+}
+
+/**
+ * disable_interrupts() - disable the interrupts
+ * @dev: private data of controller
+ */
+static int disable_interrupts(struct nmk_i2c_dev *dev, u32 irq)
+{
+	irq = IRQ_MASK(irq);
+	writel(readl(dev->virtbase + I2C_IMSCR) & ~(I2C_CLEAR_ALL_INTS & irq),
+			dev->virtbase + I2C_IMSCR);
+	return 0;
+}
+
+/**
+ * i2c_irq_handler() - interrupt routine
+ * @irq: interrupt number
+ * @arg: data passed to the handler
+ *
+ * This is the interrupt handler for the i2c driver. Currently
+ * it handles the major interrupts like Rx & Tx FIFO management
+ * interrupts, master transaction interrupts, arbitration and
+ * bus error interrupts. The rest of the interrupts are treated as
+ * unhandled.
+ */
+static irqreturn_t i2c_irq_handler(int irq, void *arg)
+{
+	struct nmk_i2c_dev *dev = arg;
+	u32 tft, rft;
+	u32 count;
+	u32 misr;
+	u32 src = 0;
+
+	/* load Tx FIFO and Rx FIFO threshold values */
+	tft = readl(dev->virtbase + I2C_TFTR);
+	rft = readl(dev->virtbase + I2C_RFTR);
+
+	/* read interrupt status register */
+	misr = readl(dev->virtbase + I2C_MISR);
+
+	src = __ffs(misr);
+	switch ((1 << src)) {
+
+	/* Transmit FIFO nearly empty interrupt */
+	case I2C_IT_TXFNE:
+	{
+		if (dev->cli.operation == I2C_READ) {
+			/*
+			 * in read operation why do we care for writing?
+			 * so disable the Transmit FIFO interrupt
+			 */
+			disable_interrupts(dev, I2C_IT_TXFNE);
+		} else {
+			for (count = (MAX_I2C_FIFO_THRESHOLD - tft - 2);
+					(count > 0) &&
+					(dev->cli.count != 0);
+					count--) {
+				/* write to the Tx FIFO */
+				writeb(*dev->cli.buffer,
+					dev->virtbase + I2C_TFR);
+				dev->cli.buffer++;
+				dev->cli.count--;
+				dev->cli.xfer_bytes++;
+			}
+			/*
+			 * if done, close the transfer by disabling the
+			 * corresponding TXFNE interrupt
+			 */
+			if (dev->cli.count == 0)
+				disable_interrupts(dev,	I2C_IT_TXFNE);
+		}
+	}
+	break;
+
+	/*
+	 * Rx FIFO nearly full interrupt.
+	 * This is set when the numer of entries in Rx FIFO is
+	 * greater or equal than the threshold value programmed
+	 * in RFT
+	 */
+	case I2C_IT_RXFNF:
+		for (count = rft; count > 0; count--) {
+			/* Read the Rx FIFO */
+			*dev->cli.buffer = readb(dev->virtbase + I2C_RFR);
+			dev->cli.buffer++;
+		}
+		dev->cli.count -= rft;
+		dev->cli.xfer_bytes += rft;
+		break;
+
+	/* Rx FIFO full */
+	case I2C_IT_RXFF:
+		for (count = MAX_I2C_FIFO_THRESHOLD; count > 0; count--) {
+			*dev->cli.buffer = readb(dev->virtbase + I2C_RFR);
+			dev->cli.buffer++;
+		}
+		dev->cli.count -= MAX_I2C_FIFO_THRESHOLD;
+		dev->cli.xfer_bytes += MAX_I2C_FIFO_THRESHOLD;
+		break;
+
+	/* Master Transaction Done with/without stop */
+	case I2C_IT_MTD:
+	case I2C_IT_MTDWS:
+		if (dev->cli.operation == I2C_READ) {
+			while (!readl(dev->virtbase + I2C_RISR) & I2C_IT_RXFE) {
+				if (dev->cli.count == 0)
+					break;
+				*dev->cli.buffer =
+					readb(dev->virtbase + I2C_RFR);
+				dev->cli.buffer++;
+				dev->cli.count--;
+				dev->cli.xfer_bytes++;
+			}
+		}
+
+		i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MTD);
+		i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MTDWS);
+
+		disable_interrupts(dev,
+				(I2C_IT_TXFNE | I2C_IT_TXFE | I2C_IT_TXFF
+					| I2C_IT_TXFOVR | I2C_IT_RXFNF
+					| I2C_IT_RXFF | I2C_IT_RXFE));
+
+		if (dev->cli.count) {
+			dev->result = -1;
+			dev_err(&dev->pdev->dev, "%lu bytes still remain to be"
+					"xfered\n", dev->cli.count);
+			(void) init_hw(dev);
+		}
+		complete(&dev->xfer_complete);
+
+		break;
+
+	/* Master Arbitration lost interrupt */
+	case I2C_IT_MAL:
+		dev->result = -1;
+		(void) init_hw(dev);
+
+		i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MAL);
+		complete(&dev->xfer_complete);
+
+		break;
+
+	/*
+	 * Bus Error interrupt.
+	 * This happens when an unexpected start/stop condition occurs
+	 * during the transaction.
+	 */
+	case I2C_IT_BERR:
+		dev->result = -1;
+		/* get the status */
+		if (((readl(dev->virtbase + I2C_SR) >> 2) & 0x3) == I2C_ABORT)
+			(void) init_hw(dev);
+
+		i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_BERR);
+		complete(&dev->xfer_complete);
+
+		break;
+
+	/*
+	 * Tx FIFO overrun interrupt.
+	 * This is set when a write operation in Tx FIFO is performed and
+	 * the Tx FIFO is full.
+	 */
+	case I2C_IT_TXFOVR:
+		dev->result = -1;
+		(void) init_hw(dev);
+
+		dev_err(&dev->pdev->dev, "Tx Fifo Over run\n");
+		complete(&dev->xfer_complete);
+
+		break;
+
+	/* unhandled interrupts by this driver - TODO*/
+	case I2C_IT_TXFE:
+	case I2C_IT_TXFF:
+	case I2C_IT_RXFE:
+	case I2C_IT_RFSR:
+	case I2C_IT_RFSE:
+	case I2C_IT_WTSR:
+	case I2C_IT_STD:
+		dev_err(&dev->pdev->dev, "unhandled Interrupt\n");
+		break;
+	default:
+		dev_err(&dev->pdev->dev, "spurious Interrupt..\n");
+		break;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int nmk_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C
+		| I2C_FUNC_SMBUS_BYTE_DATA
+		| I2C_FUNC_SMBUS_WORD_DATA
+		| I2C_FUNC_SMBUS_I2C_BLOCK;
+}
+
+static const struct i2c_algorithm nmk_i2c_algo = {
+	.master_xfer	= nmk_i2c_xfer,
+	.functionality	= nmk_i2c_functionality
+};
+
+static int __devinit nmk_i2c_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct resource *res;
+	struct nmk_i2c_controller *pdata =
+			pdev->dev.platform_data;
+	struct nmk_i2c_dev	*dev;
+	struct i2c_adapter *adap;
+
+	dev = kzalloc(sizeof(struct nmk_i2c_dev), GFP_KERNEL);
+	if (!dev) {
+		dev_err(&pdev->dev, "cannot allocate memory\n");
+		ret = -ENOMEM;
+		goto err_no_mem;
+	}
+
+	dev->pdev = pdev;
+	platform_set_drvdata(pdev, dev);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		ret = -ENOENT;
+		goto err_no_resource;
+	}
+
+	if (request_mem_region(res->start, resource_size(res),
+		DRIVER_NAME "I/O region") == 	NULL)	{
+		ret = -EBUSY;
+		goto err_no_region;
+	}
+
+	dev->virtbase = ioremap(res->start, resource_size(res));
+	if (!dev->virtbase) {
+		ret = -ENOMEM;
+		goto err_no_ioremap;
+	}
+
+	dev->irq = platform_get_irq(pdev, 0);
+	ret = request_irq(dev->irq, i2c_irq_handler, IRQF_DISABLED,
+				DRIVER_NAME, dev);
+	if (ret) {
+		dev_err(&pdev->dev, "cannot claim the irq %d\n", dev->irq);
+		goto err_irq;
+	}
+
+	dev->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(dev->clk)) {
+		dev_err(&pdev->dev, "could not get i2c clock\n");
+		ret = PTR_ERR(dev->clk);
+		goto err_no_clk;
+	}
+
+	clk_enable(dev->clk);
+
+	adap = &dev->adap;
+	adap->dev.parent = &pdev->dev;
+	adap->owner	= THIS_MODULE;
+	adap->class	= I2C_CLASS_HWMON | I2C_CLASS_SPD;
+	adap->algo	= &nmk_i2c_algo;
+
+	/* fetch the controller id */
+	adap->nr	= pdev->id;
+
+	/* fetch the controller configuration from machine */
+	dev->cfg.clk_freq = pdata->clk_freq;
+	dev->cfg.slsu	= pdata->slsu;
+	dev->cfg.tft	= pdata->tft;
+	dev->cfg.rft	= pdata->rft;
+	dev->cfg.sm	= pdata->sm;
+
+	i2c_set_adapdata(adap, dev);
+
+	ret = init_hw(dev);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "error in initializing i2c hardware\n");
+		goto err_init_hw;
+	}
+
+	dev_dbg(&pdev->dev, "initialize I2C%d bus on virtual "
+		"base %p\n", pdev->id, dev->virtbase);
+
+	ret = i2c_add_numbered_adapter(adap);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to add adapter\n");
+		goto err_add_adap;
+	}
+
+	return 0;
+
+ err_init_hw:
+	clk_disable(dev->clk);
+ err_add_adap:
+	clk_put(dev->clk);
+ err_no_clk:
+	free_irq(dev->irq, dev);
+ err_irq:
+	iounmap(dev->virtbase);
+ err_no_ioremap:
+	release_mem_region(res->start, resource_size(res));
+ err_no_region:
+	platform_set_drvdata(pdev, NULL);
+ err_no_resource:
+	kfree(dev);
+ err_no_mem:
+
+	return ret;
+}
+
+static int __devexit nmk_i2c_remove(struct platform_device *pdev)
+{
+	struct nmk_i2c_dev *dev = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&dev->adap);
+	flush_i2c_fifo(dev);
+	disable_all_interrupts(dev);
+	clear_all_interrupts(dev);
+	/* disable the controller */
+	i2c_clr_bit(dev->virtbase + I2C_CR, I2C_CR_PE);
+	free_irq(dev->irq, dev);
+	iounmap(dev->virtbase);
+	clk_disable(dev->clk);
+	clk_put(dev->clk);
+	platform_set_drvdata(pdev, NULL);
+	kfree(dev);
+
+	return 0;
+}
+
+static struct platform_driver nmk_i2c_driver = {
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = DRIVER_NAME,
+	},
+	.probe = nmk_i2c_probe,
+	.remove = __devexit_p(nmk_i2c_remove),
+};
+
+static int __init nmk_i2c_init(void)
+{
+	return platform_driver_register(&nmk_i2c_driver);
+}
+
+static void __exit nmk_i2c_exit(void)
+{
+	platform_driver_unregister(&nmk_i2c_driver);
+}
+
+subsys_initcall(nmk_i2c_init);
+module_exit(nmk_i2c_exit);
+
+MODULE_AUTHOR("Sachin Verma, Srinidhi KASAGAR");
+MODULE_DESCRIPTION("Nomadik/Ux500 I2C driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRIVER_NAME);

drivers/i2c/busses/i2c-omap.c

···
 #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
 
 #define OMAP_I2C_REV_REG		0x00
-#define OMAP_I2C_IE_REG			0x04
-#define OMAP_I2C_STAT_REG		0x08
-#define OMAP_I2C_IV_REG			0x0c
+#define OMAP_I2C_IE_REG			0x01
+#define OMAP_I2C_STAT_REG		0x02
+#define OMAP_I2C_IV_REG			0x03
 /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
-#define OMAP_I2C_WE_REG			0x0c
-#define OMAP_I2C_SYSS_REG		0x10
-#define OMAP_I2C_BUF_REG		0x14
-#define OMAP_I2C_CNT_REG		0x18
-#define OMAP_I2C_DATA_REG		0x1c
-#define OMAP_I2C_SYSC_REG		0x20
-#define OMAP_I2C_CON_REG		0x24
-#define OMAP_I2C_OA_REG			0x28
-#define OMAP_I2C_SA_REG			0x2c
-#define OMAP_I2C_PSC_REG		0x30
-#define OMAP_I2C_SCLL_REG		0x34
-#define OMAP_I2C_SCLH_REG		0x38
-#define OMAP_I2C_SYSTEST_REG		0x3c
-#define OMAP_I2C_BUFSTAT_REG		0x40
+#define OMAP_I2C_WE_REG			0x03
+#define OMAP_I2C_SYSS_REG		0x04
+#define OMAP_I2C_BUF_REG		0x05
+#define OMAP_I2C_CNT_REG		0x06
+#define OMAP_I2C_DATA_REG		0x07
+#define OMAP_I2C_SYSC_REG		0x08
+#define OMAP_I2C_CON_REG		0x09
+#define OMAP_I2C_OA_REG			0x0a
+#define OMAP_I2C_SA_REG			0x0b
+#define OMAP_I2C_PSC_REG		0x0c
+#define OMAP_I2C_SCLL_REG		0x0d
+#define OMAP_I2C_SCLH_REG		0x0e
+#define OMAP_I2C_SYSTEST_REG		0x0f
+#define OMAP_I2C_BUFSTAT_REG		0x10
 
 /* I2C Interrupt Enable Register (OMAP_I2C_IE): */
 #define OMAP_I2C_IE_XDR		(1 << 14)	/* TX Buffer drain int enable */
···
 	struct device		*dev;
 	void __iomem		*base;		/* virtual */
 	int			irq;
+	int			reg_shift;      /* bit shift for I2C register addresses */
 	struct clk		*iclk;		/* Interface clock */
 	struct clk		*fclk;		/* Functional clock */
 	struct completion	cmd_complete;
···
 static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
 				      int reg, u16 val)
 {
-	__raw_writew(val, i2c_dev->base + reg);
+	__raw_writew(val, i2c_dev->base + (reg << i2c_dev->reg_shift));
 }
 
 static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
 {
-	return __raw_readw(i2c_dev->base + reg);
+	return __raw_readw(i2c_dev->base + (reg << i2c_dev->reg_shift));
 }
 
 static int __init omap_i2c_get_clocks(struct omap_i2c_dev *dev)
···
 		dev->fifo_size = (dev->fifo_size / 2);
 		dev->b_hw = 1; /* Enable hardware fixes */
 	}
+
+	if (cpu_is_omap7xx())
+		dev->reg_shift = 1;
+	else
+		dev->reg_shift = 2;
 
 	/* reset ASAP, clearing any IRQs */
 	omap_i2c_init(dev);

drivers/i2c/busses/i2c-pnx.c

···
 		/* We still have something to talk about... */
 		val = *alg_data->mif.buf++;
 
-		if (alg_data->mif.len == 1) {
-			val |= stop_bit;
-			if (!alg_data->last)
-				val |= start_bit;
-		}
-
 		alg_data->mif.len--;
 		iowrite32(val, I2C_REG_TX(alg_data));
 
···
 			__func__);
 
 		if (alg_data->mif.len == 1) {
-			/* Last byte, do not acknowledge next rcv. */
-			val |= stop_bit;
-			if (!alg_data->last)
-				val |= start_bit;
-
 			/*
 			 * Enable interrupt RFDAIE (data in Rx fifo),
 			 * and disable DRMIE (need data for Tx)

drivers/i2c/busses/i2c-xiic.c

···
+/*
+ * i2c-xiic.c
+ * Copyright (c) 2002-2007 Xilinx Inc.
+ * Copyright (c) 2009-2010 Intel Corporation
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *
+ * This code was implemented by Mocean Laboratories AB when porting linux
+ * to the automotive development board Russellville. The copyright holder
+ * as seen in the header is Intel corporation.
+ * Mocean Laboratories forked off the GNU/Linux platform work into a
+ * separate company called Pelagicore AB, which commited the code to the
+ * kernel.
+ */
+
+/* Supports:
+ * Xilinx IIC
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/wait.h>
+#include <linux/i2c-xiic.h>
+#include <linux/io.h>
+
+#define DRIVER_NAME "xiic-i2c"
+
+enum xilinx_i2c_state {
+	STATE_DONE,
+	STATE_ERROR,
+	STATE_START
+};
+
+/**
+ * struct xiic_i2c - Internal representation of the XIIC I2C bus
+ * @base:	Memory base of the HW registers
+ * @wait:	Wait queue for callers
+ * @adap:	Kernel adapter representation
+ * @tx_msg:	Messages from above to be sent
+ * @lock:	Mutual exclusion
+ * @tx_pos:	Current pos in TX message
+ * @nmsgs:	Number of messages in tx_msg
+ * @state:	See STATE_
+ * @rx_msg:	Current RX message
+ * @rx_pos:	Position within current RX message
+ */
+struct xiic_i2c {
+	void __iomem		*base;
+	wait_queue_head_t	wait;
+	struct i2c_adapter	adap;
+	struct i2c_msg		*tx_msg;
+	spinlock_t		lock;
+	unsigned int 		tx_pos;
+	unsigned int		nmsgs;
+	enum xilinx_i2c_state	state;
+	struct i2c_msg		*rx_msg;
+	int			rx_pos;
+};
+
+
+#define XIIC_MSB_OFFSET 0
+#define XIIC_REG_OFFSET (0x100+XIIC_MSB_OFFSET)
+
+/*
+ * Register offsets in bytes from RegisterBase. Three is added to the
+ * base offset to access LSB (IBM style) of the word
+ */
+#define XIIC_CR_REG_OFFSET   (0x00+XIIC_REG_OFFSET)	/* Control Register   */
+#define XIIC_SR_REG_OFFSET   (0x04+XIIC_REG_OFFSET)	/* Status Register    */
+#define XIIC_DTR_REG_OFFSET  (0x08+XIIC_REG_OFFSET)	/* Data Tx Register   */
+#define XIIC_DRR_REG_OFFSET  (0x0C+XIIC_REG_OFFSET)	/* Data Rx Register   */
+#define XIIC_ADR_REG_OFFSET  (0x10+XIIC_REG_OFFSET)	/* Address Register   */
+#define XIIC_TFO_REG_OFFSET  (0x14+XIIC_REG_OFFSET)	/* Tx FIFO Occupancy  */
+#define XIIC_RFO_REG_OFFSET  (0x18+XIIC_REG_OFFSET)	/* Rx FIFO Occupancy  */
+#define XIIC_TBA_REG_OFFSET  (0x1C+XIIC_REG_OFFSET)	/* 10 Bit Address reg */
+#define XIIC_RFD_REG_OFFSET  (0x20+XIIC_REG_OFFSET)	/* Rx FIFO Depth reg  */
+#define XIIC_GPO_REG_OFFSET  (0x24+XIIC_REG_OFFSET)	/* Output Register    */
+
+/* Control Register masks */
+#define XIIC_CR_ENABLE_DEVICE_MASK        0x01	/* Device enable = 1      */
+#define XIIC_CR_TX_FIFO_RESET_MASK        0x02	/* Transmit FIFO reset=1  */
+#define XIIC_CR_MSMS_MASK                 0x04	/* Master starts Txing=1  */
+#define XIIC_CR_DIR_IS_TX_MASK            0x08	/* Dir of tx. Txing=1     */
+#define XIIC_CR_NO_ACK_MASK               0x10	/* Tx Ack. NO ack = 1     */
+#define XIIC_CR_REPEATED_START_MASK       0x20	/* Repeated start = 1     */
+#define XIIC_CR_GENERAL_CALL_MASK         0x40	/* Gen Call enabled = 1   */
+
+/* Status Register masks */
+#define XIIC_SR_GEN_CALL_MASK             0x01	/* 1=a mstr issued a GC   */
+#define XIIC_SR_ADDR_AS_SLAVE_MASK        0x02	/* 1=when addr as slave   */
+#define XIIC_SR_BUS_BUSY_MASK             0x04	/* 1 = bus is busy        */
+#define XIIC_SR_MSTR_RDING_SLAVE_MASK     0x08	/* 1=Dir: mstr <-- slave  */
+#define XIIC_SR_TX_FIFO_FULL_MASK         0x10	/* 1 = Tx FIFO full       */
+#define XIIC_SR_RX_FIFO_FULL_MASK         0x20	/* 1 = Rx FIFO full       */
+#define XIIC_SR_RX_FIFO_EMPTY_MASK        0x40	/* 1 = Rx FIFO empty      */
+#define XIIC_SR_TX_FIFO_EMPTY_MASK        0x80	/* 1 = Tx FIFO empty      */
+
+/* Interrupt Status Register masks    Interrupt occurs when...       */
+#define XIIC_INTR_ARB_LOST_MASK           0x01	/* 1 = arbitration lost   */
+#define XIIC_INTR_TX_ERROR_MASK           0x02	/* 1=Tx error/msg complete */
+#define XIIC_INTR_TX_EMPTY_MASK           0x04	/* 1 = Tx FIFO/reg empty  */
+#define XIIC_INTR_RX_FULL_MASK            0x08	/* 1=Rx FIFO/reg=OCY level */
+#define XIIC_INTR_BNB_MASK                0x10	/* 1 = Bus not busy       */
+#define XIIC_INTR_AAS_MASK                0x20	/* 1 = when addr as slave */
+#define XIIC_INTR_NAAS_MASK               0x40	/* 1 = not addr as slave  */
+#define XIIC_INTR_TX_HALF_MASK            0x80	/* 1 = TX FIFO half empty */
+
+/* The following constants specify the depth of the FIFOs */
+#define IIC_RX_FIFO_DEPTH         16	/* Rx fifo capacity               */
+#define IIC_TX_FIFO_DEPTH         16	/* Tx fifo capacity               */
+
+/* The following constants specify groups of interrupts that are typically
+ * enabled or disables at the same time
+ */
+#define XIIC_TX_INTERRUPTS                           \
+(XIIC_INTR_TX_ERROR_MASK | XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)
+
+#define XIIC_TX_RX_INTERRUPTS (XIIC_INTR_RX_FULL_MASK | XIIC_TX_INTERRUPTS)
+
+/* The following constants are used with the following macros to specify the
+ * operation, a read or write operation.
+ */
+#define XIIC_READ_OPERATION  1
+#define XIIC_WRITE_OPERATION 0
+
+/*
+ * Tx Fifo upper bit masks.
+ */
+#define XIIC_TX_DYN_START_MASK            0x0100 /* 1 = Set dynamic start */
+#define XIIC_TX_DYN_STOP_MASK             0x0200 /* 1 = Set dynamic stop */
+
+/*
+ * The following constants define the register offsets for the Interrupt
+ * registers. There are some holes in the memory map for reserved addresses
+ * to allow other registers to be added and still match the memory map of the
+ * interrupt controller registers
+ */
+#define XIIC_DGIER_OFFSET    0x1C /* Device Global Interrupt Enable Register */
+#define XIIC_IISR_OFFSET     0x20 /* Interrupt Status Register */
+#define XIIC_IIER_OFFSET     0x28 /* Interrupt Enable Register */
+#define XIIC_RESETR_OFFSET   0x40 /* Reset Register */
+
+#define XIIC_RESET_MASK             0xAUL
+
+/*
+ * The following constant is used for the device global interrupt enable
+ * register, to enable all interrupts for the device, this is the only bit
+ * in the register
+ */
+#define XIIC_GINTR_ENABLE_MASK      0x80000000UL
+
+#define xiic_tx_space(i2c) ((i2c)->tx_msg->len - (i2c)->tx_pos)
+#define xiic_rx_space(i2c) ((i2c)->rx_msg->len - (i2c)->rx_pos)
+
+static void xiic_start_xfer(struct xiic_i2c *i2c);
+static void __xiic_start_xfer(struct xiic_i2c *i2c);
+
+static inline void xiic_setreg8(struct xiic_i2c *i2c, int reg, u8 value)
+{
+	iowrite8(value, i2c->base + reg);
+}
+
+static inline u8 xiic_getreg8(struct xiic_i2c *i2c, int reg)
+{
+	return ioread8(i2c->base + reg);
+}
+
+static inline void xiic_setreg16(struct xiic_i2c *i2c, int reg, u16 value)
+{
+	iowrite16(value, i2c->base + reg);
+}
+
+static inline void xiic_setreg32(struct xiic_i2c *i2c, int reg, int value)
+{
+	iowrite32(value, i2c->base + reg);
+}
+
+static inline int xiic_getreg32(struct xiic_i2c *i2c, int reg)
+{
+	return ioread32(i2c->base + reg);
+}
+
+static inline void xiic_irq_dis(struct xiic_i2c *i2c, u32 mask)
+{
+	u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
+	xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier & ~mask);
+}
+
+static inline void xiic_irq_en(struct xiic_i2c *i2c, u32 mask)
+{
+	u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
+	xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier | mask);
+}
+
+static inline void xiic_irq_clr(struct xiic_i2c *i2c, u32 mask)
+{
+	u32 isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET);
+	xiic_setreg32(i2c, XIIC_IISR_OFFSET, isr & mask);
+}
+
+static inline void xiic_irq_clr_en(struct xiic_i2c *i2c, u32 mask)
+{
+	xiic_irq_clr(i2c, mask);
+	xiic_irq_en(i2c, mask);
+}
+
+static void xiic_clear_rx_fifo(struct xiic_i2c *i2c)
+{
+	u8 sr;
+	for (sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET);
+		!(sr & XIIC_SR_RX_FIFO_EMPTY_MASK);
+		sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET))
+		xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET);
+}
+
+static void xiic_reinit(struct xiic_i2c *i2c)
+{
+	xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK);
+
+	/* Set receive Fifo depth to maximum (zero based). */
+	xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, IIC_RX_FIFO_DEPTH - 1);
+
+	/* Reset Tx Fifo. */
+	xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_TX_FIFO_RESET_MASK);
+
+	/* Enable IIC Device, remove Tx Fifo reset & disable general call. */
+	xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_ENABLE_DEVICE_MASK);
+
+	/* make sure RX fifo is empty */
+	xiic_clear_rx_fifo(i2c);
+
+	/* Enable interrupts */
+	xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK);
+
+	xiic_irq_clr_en(i2c, XIIC_INTR_AAS_MASK | XIIC_INTR_ARB_LOST_MASK);
+}
+
+static void xiic_deinit(struct xiic_i2c *i2c)
+{
+	u8 cr;
+
+	xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK);
+
+	/* Disable IIC Device. */
+	cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET);
+	xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & ~XIIC_CR_ENABLE_DEVICE_MASK);
+}
+
+static void xiic_read_rx(struct xiic_i2c *i2c)
+{
+	u8 bytes_in_fifo;
+	int i;
+
+	bytes_in_fifo = xiic_getreg8(i2c, XIIC_RFO_REG_OFFSET) + 1;
+
+	dev_dbg(i2c->adap.dev.parent, "%s entry, bytes in fifo: %d, msg: %d"
+		", SR: 0x%x, CR: 0x%x\n",
+		__func__, bytes_in_fifo, xiic_rx_space(i2c),
+		xiic_getreg8(i2c, XIIC_SR_REG_OFFSET),
+		xiic_getreg8(i2c, XIIC_CR_REG_OFFSET));
+
+	if (bytes_in_fifo > xiic_rx_space(i2c))
+		bytes_in_fifo = xiic_rx_space(i2c);
+
+	for (i = 0; i < bytes_in_fifo; i++)
+		i2c->rx_msg->buf[i2c->rx_pos++] =
+			xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET);
+
+	xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET,
+		(xiic_rx_space(i2c) > IIC_RX_FIFO_DEPTH) ?
+		IIC_RX_FIFO_DEPTH - 1 :  xiic_rx_space(i2c) - 1);
+}
+
+static int xiic_tx_fifo_space(struct xiic_i2c *i2c)
+{
+	/* return the actual space left in the FIFO */
+	return IIC_TX_FIFO_DEPTH - xiic_getreg8(i2c, XIIC_TFO_REG_OFFSET) - 1;
+}
+
+static void xiic_fill_tx_fifo(struct xiic_i2c *i2c)
+{
+	u8 fifo_space = xiic_tx_fifo_space(i2c);
+	int len = xiic_tx_space(i2c);
+
+	len = (len > fifo_space) ? fifo_space : len;
+
+	dev_dbg(i2c->adap.dev.parent, "%s entry, len: %d, fifo space: %d\n",
+		__func__, len, fifo_space);
+
+	while (len--) {
+		u16 data = i2c->tx_msg->buf[i2c->tx_pos++];
+		if ((xiic_tx_space(i2c) == 0) && (i2c->nmsgs == 1)) {
+			/* last message in transfer -> STOP */
+			data |= XIIC_TX_DYN_STOP_MASK;
+			dev_dbg(i2c->adap.dev.parent, "%s TX STOP\n", __func__);
+
+			xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data);
+		} else
+			xiic_setreg8(i2c, XIIC_DTR_REG_OFFSET, data);
+	}
+}
+
+static void xiic_wakeup(struct xiic_i2c *i2c, int code)
+{
+	i2c->tx_msg = NULL;
+	i2c->rx_msg = NULL;
+	i2c->nmsgs = 0;
+	i2c->state = code;
+	wake_up(&i2c->wait);
+}
+
+static void xiic_process(struct xiic_i2c *i2c)
+{
+	u32 pend, isr, ier;
+	u32 clr = 0;
+
+	/* Get the interrupt Status from the IPIF. There is no clearing of
+	 * interrupts in the IPIF. Interrupts must be cleared at the source.
+	 * To find which interrupts are pending; AND interrupts pending with
+	 * interrupts masked.
+	 */
+	isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET);
+	ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
+	pend = isr & ier;
+
+	dev_dbg(i2c->adap.dev.parent, "%s entry, IER: 0x%x, ISR: 0x%x, "
+		"pend: 0x%x, SR: 0x%x, msg: %p, nmsgs: %d\n",
+		__func__, ier, isr, pend, xiic_getreg8(i2c, XIIC_SR_REG_OFFSET),
+		i2c->tx_msg, i2c->nmsgs);
+
+	/* Do not processes a devices interrupts if the device has no
+	 * interrupts pending
+	 */
+	if (!pend)
+		return;
+
+	/* Service requesting interrupt */
+	if ((pend & XIIC_INTR_ARB_LOST_MASK) ||
+		((pend & XIIC_INTR_TX_ERROR_MASK) &&
+		!(pend & XIIC_INTR_RX_FULL_MASK))) {
+		/* bus arbritration lost, or...
+		 * Transmit error _OR_ RX completed
+		 * if this happens when RX_FULL is not set
+		 * this is probably a TX error
+		 */
+
+		dev_dbg(i2c->adap.dev.parent, "%s error\n", __func__);
+
+		/* dynamic mode seem to suffer from problems if we just flushes
+		 * fifos and the next message is a TX with len 0 (only addr)
+		 * reset the IP instead of just flush fifos
+		 */
+		xiic_reinit(i2c);
+
+		if (i2c->tx_msg)
+			xiic_wakeup(i2c, STATE_ERROR);
+
+	} else if (pend & XIIC_INTR_RX_FULL_MASK) {
+		/* Receive register/FIFO is full */
+
+		clr = XIIC_INTR_RX_FULL_MASK;
+		if (!i2c->rx_msg) {
+			dev_dbg(i2c->adap.dev.parent,
+				"%s unexpexted RX IRQ\n", __func__);
+			xiic_clear_rx_fifo(i2c);
+			goto out;
+		}
+
+		xiic_read_rx(i2c);
+		if (xiic_rx_space(i2c) == 0) {
+			/* this is the last part of the message */
+			i2c->rx_msg = NULL;
+
+			/* also clear TX error if there (RX complete) */
+			clr |= (isr & XIIC_INTR_TX_ERROR_MASK);
+
+			dev_dbg(i2c->adap.dev.parent,
+				"%s end of message, nmsgs: %d\n",
+				__func__, i2c->nmsgs);
+
+			/* send next message if this wasn't the last,
+			 * otherwise the transfer will be finialise when
+			 * receiving the bus not busy interrupt
+			 */
+			if (i2c->nmsgs > 1) {
+				i2c->nmsgs--;
+				i2c->tx_msg++;
+				dev_dbg(i2c->adap.dev.parent,
+					"%s will start next...\n", __func__);
+
+				__xiic_start_xfer(i2c);
+			}
+		}
+	} else if (pend & XIIC_INTR_BNB_MASK) {
+		/* IIC bus has transitioned to not busy */
+		clr = XIIC_INTR_BNB_MASK;
+
+		/* The bus is not busy, disable BusNotBusy interrupt */
+		xiic_irq_dis(i2c, XIIC_INTR_BNB_MASK);
+
+		if (!i2c->tx_msg)
+			goto out;
+
+		if ((i2c->nmsgs == 1) && !i2c->rx_msg &&
+			xiic_tx_space(i2c) == 0)
+			xiic_wakeup(i2c, STATE_DONE);
+		else
+			xiic_wakeup(i2c, STATE_ERROR);
+
+	} else if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) {
+		/* Transmit register/FIFO is empty or � empty */
+
+		clr = pend &
+			(XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK);
+
+		if (!i2c->tx_msg) {
+			dev_dbg(i2c->adap.dev.parent,
+				"%s unexpexted TX IRQ\n", __func__);
+			goto out;
+		}
+
+		xiic_fill_tx_fifo(i2c);
+
+		/* current message sent and there is space in the fifo */
+		if (!xiic_tx_space(i2c) && xiic_tx_fifo_space(i2c) >= 2) {
+			dev_dbg(i2c->adap.dev.parent,
+				"%s end of message sent, nmsgs: %d\n",
+				__func__, i2c->nmsgs);
+			if (i2c->nmsgs > 1) {
+				i2c->nmsgs--;
+				i2c->tx_msg++;
+				__xiic_start_xfer(i2c);
+			} else {
+				xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
+
+				dev_dbg(i2c->adap.dev.parent,
+					"%s Got TX IRQ but no more to do...\n",
+					__func__);
+			}
+		} else if (!xiic_tx_space(i2c) && (i2c->nmsgs == 1))
+			/* current frame is sent and is last,
+			 * make sure to disable tx half
+			 */
+			xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
+	} else {
+		/* got IRQ which is not acked */
+		dev_err(i2c->adap.dev.parent, "%s Got unexpected IRQ\n",
+			__func__);
+		clr = pend;
+	}
+out:
+	dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr);
+
+	xiic_setreg32(i2c, XIIC_IISR_OFFSET, clr);
+}
+
+static int xiic_bus_busy(struct xiic_i2c *i2c)
+{
+	u8 sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET);
+
+	return (sr & XIIC_SR_BUS_BUSY_MASK) ? -EBUSY : 0;
+}
+
+static int xiic_busy(struct xiic_i2c *i2c)
+{
+	int tries = 3;
+	int err;
+
+	if (i2c->tx_msg)
+		return -EBUSY;
+
+	/* for instance if previous transfer was terminated due to TX error
+	 * it might be that the bus is on it's way to become available
+	 * give it at most 3 ms to wake
+	 */
+	err = xiic_bus_busy(i2c);
+	while (err && tries--) {
+		mdelay(1);
+		err = xiic_bus_busy(i2c);
+	}
+
+	return err;
+}
+
+static void xiic_start_recv(struct xiic_i2c *i2c)
+{
+	u8 rx_watermark;
+	struct i2c_msg *msg = i2c->rx_msg = i2c->tx_msg;
+
+	/* Clear and enable Rx full interrupt. */
+	xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | XIIC_INTR_TX_ERROR_MASK);
+
+	/* we want to get all but last byte, because the TX_ERROR IRQ is used
+	 * to inidicate error ACK on the address, and negative ack on the last
+	 * received byte, so to not mix them receive all but last.
+	 * In the case where there is only one byte to receive
+	 * we can check if ERROR and RX full is set at the same time
+	 */
+	rx_watermark = msg->len;
+	if (rx_watermark > IIC_RX_FIFO_DEPTH)
+		rx_watermark = IIC_RX_FIFO_DEPTH;
+	xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, rx_watermark - 1);
+
+	if (!(msg->flags & I2C_M_NOSTART))
+		/* write the address */
+		xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET,
+			(msg->addr << 1) | XIIC_READ_OPERATION |
+			XIIC_TX_DYN_START_MASK);
+
+	xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK);
+
+	xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET,
+		msg->len | ((i2c->nmsgs == 1) ? XIIC_TX_DYN_STOP_MASK : 0));
+	if (i2c->nmsgs == 1)
+		/* very last, enable bus not busy as well */
+		xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK);
+
+	/* the message is tx:ed */
+	i2c->tx_pos = msg->len;
+}
+
+static void xiic_start_send(struct xiic_i2c *i2c)
+{
+	struct i2c_msg *msg = i2c->tx_msg;
+
+	xiic_irq_clr(i2c, XIIC_INTR_TX_ERROR_MASK);
+
+	dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, len: %d, "
+		"ISR: 0x%x, CR: 0x%x\n",
+		__func__, msg, msg->len, xiic_getreg32(i2c, XIIC_IISR_OFFSET),
+		xiic_getreg8(i2c, XIIC_CR_REG_OFFSET));
+
+	if (!(msg->flags & I2C_M_NOSTART)) {
+		/* write the address */
+		u16 data = ((msg->addr << 1) & 0xfe) | XIIC_WRITE_OPERATION |
+			XIIC_TX_DYN_START_MASK;
+		if ((i2c->nmsgs == 1) && msg->len == 0)
+			/* no data and last message -> add STOP */
+			data |= XIIC_TX_DYN_STOP_MASK;
+
+		xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data);
+	}
+
+	xiic_fill_tx_fifo(i2c);
+
+	/* Clear any pending Tx empty, Tx Error and then enable them. */
+	xiic_irq_clr_en(i2c, XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_ERROR_MASK |
+		XIIC_INTR_BNB_MASK);
+}
+
+static irqreturn_t xiic_isr(int irq, void *dev_id)
+{
+	struct xiic_i2c *i2c = dev_id;
+
+	spin_lock(&i2c->lock);
+	/* disable interrupts globally */
+	xiic_setreg32(i2c, XIIC_DGIER_OFFSET, 0);
+
+	dev_dbg(i2c->adap.dev.parent, "%s entry\n", __func__);
+
+	xiic_process(i2c);
+
+	xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK);
+	spin_unlock(&i2c->lock);
+
+	return IRQ_HANDLED;
+}
+
+static void __xiic_start_xfer(struct xiic_i2c *i2c)
+{
+	int first = 1;
+	int fifo_space = xiic_tx_fifo_space(i2c);
+	dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, fifos space: %d\n",
+		__func__, i2c->tx_msg, fifo_space);
+
+	if (!i2c->tx_msg)
+		return;
+
+	i2c->rx_pos = 0;
+	i2c->tx_pos = 0;
+	i2c->state = STATE_START;
+	while ((fifo_space >= 2) && (first || (i2c->nmsgs > 1))) {
+		if (!first) {
+			i2c->nmsgs--;
+			i2c->tx_msg++;
+			i2c->tx_pos = 0;
+		} else
+			first = 0;
+
+		if (i2c->tx_msg->flags & I2C_M_RD) {
+			/* we dont date putting several reads in the FIFO */
+			xiic_start_recv(i2c);
+			return;
+		} else {
+			xiic_start_send(i2c);
+			if (xiic_tx_space(i2c) != 0) {
+				/* the message could not be completely sent */
+				break;
+			}
+		}
+
+		fifo_space = xiic_tx_fifo_space(i2c);
+	}
+
+	/* there are more messages or the current one could not be completely
+	 * put into the FIFO, also enable the half empty interrupt
+	 */
+	if (i2c->nmsgs > 1 || xiic_tx_space(i2c))
+		xiic_irq_clr_en(i2c, XIIC_INTR_TX_HALF_MASK);
+
+}
+
+static void xiic_start_xfer(struct xiic_i2c *i2c)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&i2c->lock, flags);
+	xiic_reinit(i2c);
+	/* disable interrupts globally */
+	xiic_setreg32(i2c, XIIC_DGIER_OFFSET, 0);
+	spin_unlock_irqrestore(&i2c->lock, flags);
+
+	__xiic_start_xfer(i2c);
+	xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK);
+}
+
+static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+	struct xiic_i2c *i2c = i2c_get_adapdata(adap);
+	int err;
+
+	dev_dbg(adap->dev.parent, "%s entry SR: 0x%x\n", __func__,
+		xiic_getreg8(i2c, XIIC_SR_REG_OFFSET));
+
+	err = xiic_busy(i2c);
+	if (err)
+		return err;
+
+	i2c->tx_msg = msgs;
+	i2c->nmsgs = num;
+
+	xiic_start_xfer(i2c);
+
+	if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) ||
+		(i2c->state == STATE_DONE), HZ))
+		return (i2c->state == STATE_DONE) ? num : -EIO;
+	else {
+		i2c->tx_msg = NULL;
+		i2c->rx_msg = NULL;
+		i2c->nmsgs = 0;
+		return -ETIMEDOUT;
+	}
+}
+
+static u32 xiic_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm xiic_algorithm = {
+	.master_xfer	= xiic_xfer,
+	.functionality	= xiic_func,
+};
+
+static struct i2c_adapter xiic_adapter = {
+	.owner		= THIS_MODULE,
+	.name		= DRIVER_NAME,
+	.class		= I2C_CLASS_HWMON | I2C_CLASS_SPD,
+	.algo		= &xiic_algorithm,
+};
+
+
+static int __devinit xiic_i2c_probe(struct platform_device *pdev)
+{
+	struct xiic_i2c *i2c;
+	struct xiic_i2c_platform_data *pdata;
+	struct resource *res;
+	int ret, irq;
+	u8 i;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		goto resource_missing;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		goto resource_missing;
+
+	pdata = (struct xiic_i2c_platform_data *) pdev->dev.platform_data;
+	if (!pdata)
+		return -EINVAL;
+
+	i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
+	if (!i2c)
+		return -ENOMEM;
+
+	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
+		dev_err(&pdev->dev, "Memory region busy\n");
+		ret = -EBUSY;
+		goto request_mem_failed;
+	}
+
+	i2c->base = ioremap(res->start, resource_size(res));
+	if (!i2c->base) {
+		dev_err(&pdev->dev, "Unable to map registers\n");
+		ret = -EIO;
+		goto map_failed;
+	}
+
+	/* hook up driver to tree */
+	platform_set_drvdata(pdev, i2c);
+	i2c->adap = xiic_adapter;
+	i2c_set_adapdata(&i2c->adap, i2c);
+	i2c->adap.dev.parent = &pdev->dev;
+
+	xiic_reinit(i2c);
+
+	spin_lock_init(&i2c->lock);
+	init_waitqueue_head(&i2c->wait);
+	ret = request_irq(irq, xiic_isr, 0, pdev->name, i2c);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot claim IRQ\n");
+		goto request_irq_failed;
+	}
+
+	/* add i2c adapter to i2c tree */
+	ret = i2c_add_adapter(&i2c->adap);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add adapter\n");
+		goto add_adapter_failed;
+	}
+
+	/* add in known devices to the bus */
+	for (i = 0; i < pdata->num_devices; i++)
+		i2c_new_device(&i2c->adap, pdata->devices + i);
+
+	return 0;
+
+add_adapter_failed:
+	free_irq(irq, i2c);
+request_irq_failed:
+	xiic_deinit(i2c);
+	iounmap(i2c->base);
+map_failed:
+	release_mem_region(res->start, resource_size(res));
+request_mem_failed:
+	kfree(i2c);
+
+	return ret;
+resource_missing:
+	dev_err(&pdev->dev, "IRQ or Memory resource is missing\n");
+	return -ENOENT;
+}
+
+static int __devexit xiic_i2c_remove(struct platform_device* pdev)
+{
+	struct xiic_i2c *i2c = platform_get_drvdata(pdev);
+	struct resource *res;
+
+	/* remove adapter & data */
+	i2c_del_adapter(&i2c->adap);
+
+	xiic_deinit(i2c);
+
+	platform_set_drvdata(pdev, NULL);
+
+	free_irq(platform_get_irq(pdev, 0), i2c);
+
+	iounmap(i2c->base);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res)
+		release_mem_region(res->start, resource_size(res));
+
+	kfree(i2c);
+
+	return 0;
+}
+
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:"DRIVER_NAME);
+
+static struct platform_driver xiic_i2c_driver = {
+	.probe   = xiic_i2c_probe,
+	.remove  = __devexit_p(xiic_i2c_remove),
+	.driver  = {
+		.owner = THIS_MODULE,
+		.name = DRIVER_NAME,
+	},
+};
+
+static int __init xiic_i2c_init(void)
+{
+	return platform_driver_register(&xiic_i2c_driver);
+}
+
+static void __exit xiic_i2c_exit(void)
+{
+	platform_driver_unregister(&xiic_i2c_driver);
+}
+
+module_init(xiic_i2c_init);
+module_exit(xiic_i2c_exit);
+
+MODULE_AUTHOR("[e-mail]");
+MODULE_DESCRIPTION("Xilinx I2C bus driver");
+MODULE_LICENSE("GPL v2");