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

8 files changed, 1951 insertions, 108 deletions

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 4cd1ff77ced..9c6170cd9aa 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -421,13 +421,12 @@ config I2C_IXP2000
 	  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.
@@ -442,6 +441,13 @@ config I2C_MV64XXX
 	  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"
 	depends on EXPERIMENTAL
@@ -577,6 +583,16 @@ config I2C_OCTEON
 	  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"
 
 config I2C_PARPORT
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index c2c4ea1908d..097236f631e 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_I2C_IOP3XX)	+= i2c-iop3xx.o
 obj-$(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
@@ -55,6 +56,7 @@ obj-$(CONFIG_I2C_SIMTEC)	+= i2c-simtec.o
 obj-$(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
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 75bf820e7cc..32375bddae7 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -627,7 +627,6 @@ static int __exit i2c_imx_remove(struct platform_device *pdev)
 }
 
 static struct platform_driver i2c_imx_driver = {
-	.probe		= i2c_imx_probe,
 	.remove		= __exit_p(i2c_imx_remove),
 	.driver	= {
 		.name	= DRIVER_NAME,
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index f627001108b..78a15af3294 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -31,6 +31,9 @@
 
 #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
@@ -66,10 +69,9 @@ struct mpc_i2c_divider {
 	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;
 };
 
@@ -164,8 +166,8 @@ static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
 	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},
@@ -186,14 +188,15 @@ static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
 	{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 */
@@ -215,12 +218,18 @@ int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock, int prescaler)
 	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 */
 
@@ -229,16 +238,52 @@ static void mpc_i2c_setclock_52xx(struct device_node *node,
 	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 || 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_MPC52xx*/
+#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},
@@ -258,7 +303,7 @@ static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = {
 	{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;
@@ -287,13 +332,14 @@ u32 mpc_i2c_get_sec_cfg_8xxx(void)
 	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 */
@@ -320,12 +366,19 @@ int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock, u32 prescaler)
 	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 */
 
@@ -338,9 +391,9 @@ static void mpc_i2c_setclock_8xxx(struct device_node *node,
 }
 
 #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 */
@@ -494,7 +547,7 @@ static int __devinit fsl_i2c_probe(struct of_device *op,
 {
 	struct mpc_i2c *i2c;
 	const u32 *prop;
-	u32 clock = 0;
+	u32 clock = MPC_I2C_CLOCK_LEGACY;
 	int result = 0;
 	int plen;
 
@@ -523,21 +576,21 @@ static int __devinit fsl_i2c_probe(struct of_device *op,
 		}
 	}
 
-	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);
@@ -582,47 +635,42 @@ static int __devexit fsl_i2c_remove(struct of_device *op)
 	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 = {
 	.match_table	= mpc_i2c_of_match,
@@ -655,5 +703,5 @@ module_exit(fsl_i2c_exit);
 
 MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
 MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
-		   "MPC824x/85xx/52xx processors");
+		   "MPC824x/83xx/85xx/86xx/512x/52xx processors");
 MODULE_LICENSE("GPL");
diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
new file mode 100644
index 00000000000..a15f731fa45
--- /dev/null
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -0,0 +1,959 @@
+/*
+ * Copyright (C) 2009 ST-Ericsson
+ * Copyright (C) 2009 STMicroelectronics
+ *
+ * I2C master mode controller driver, used in Nomadik 8815
+ * and Ux500 platforms.
+ *
+ * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
+ * Author: Sachin Verma <sachin.verma@st.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2, as
+ * published by the Free Software Foundation.
+ */
+#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
+ *