Patchwork [v4] i2c: exynos5: add High Speed I2C controller driver

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Submitter Naveen Krishna Ch
Date Feb. 1, 2013, 3:54 p.m.
Message ID <1359734084-10594-1-git-send-email-ch.naveen@samsung.com>
Download mbox | patch
Permalink /patch/217514/
State Changes Requested
Headers show

Comments

Naveen Krishna Ch - Feb. 1, 2013, 3:54 p.m.
Adds support for High Speed I2C driver found in Exynos5 and later
SoCs from Samsung. This driver currently supports Auto mode.

Driver only supports Device Tree method.
Note: Added debugfs support for registers view, not tested.

Signed-off-by: Taekgyun Ko <taeggyun.ko@samsung.com>
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
---
Help please,

Usual reads and writes are happening. But, when i try doing
i2cdetect -y 0 0x10 0x59; It throws me continous interrupts at 0x1a
i2cdetect -y 0 0x50 0x64; It throws me continous interrupts at 0x63

There are eeproms from 0x50 till 0x58
wm8994 codec at 0x1a

Kindly, can anyone explain this behaviour.

 drivers/i2c/busses/Kconfig       |    7 +
 drivers/i2c/busses/Makefile      |    1 +
 drivers/i2c/busses/i2c-exynos5.c |  754 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 762 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-exynos5.c
Wolfram Sang - Feb. 1, 2013, 7:29 p.m.
On Fri, Feb 01, 2013 at 09:24:44PM +0530, Naveen Krishna Chatradhi wrote:
> Adds support for High Speed I2C driver found in Exynos5 and later
> SoCs from Samsung. This driver currently supports Auto mode.
> 
> Driver only supports Device Tree method.
> Note: Added debugfs support for registers view, not tested.
> 
> Signed-off-by: Taekgyun Ko <taeggyun.ko@samsung.com>
> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
> ---
> Help please,
> 
> Usual reads and writes are happening. But, when i try doing
> i2cdetect -y 0 0x10 0x59; It throws me continous interrupts at 0x1a
> i2cdetect -y 0 0x50 0x64; It throws me continous interrupts at 0x63
> 
> There are eeproms from 0x50 till 0x58
> wm8994 codec at 0x1a
> 
> Kindly, can anyone explain this behaviour.

You select I2C_FUNC_SMBUS_EMUL, but make sure your hardware really
supports I2C_FUNC_SMBUS_QUICK. That would be my first guess. Also, which
eeprom do you have? Check its datasheet, some in deed use 8 addresses.

Regards,

   Wolfram
Grant Likely - Feb. 8, 2013, 1:16 p.m.
On Fri, 01 Feb 2013 21:24:44 +0530, Naveen Krishna Chatradhi <ch.naveen@samsung.com> wrote:
> Adds support for High Speed I2C driver found in Exynos5 and later
> SoCs from Samsung. This driver currently supports Auto mode.
> 
> Driver only supports Device Tree method.
> Note: Added debugfs support for registers view, not tested.
> 
> Signed-off-by: Taekgyun Ko <taeggyun.ko@samsung.com>
> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
> ---
> Help please,
> 
> Usual reads and writes are happening. But, when i try doing
> i2cdetect -y 0 0x10 0x59; It throws me continous interrupts at 0x1a
> i2cdetect -y 0 0x50 0x64; It throws me continous interrupts at 0x63
> 
> There are eeproms from 0x50 till 0x58
> wm8994 codec at 0x1a
> 
> Kindly, can anyone explain this behaviour.
> 
>  drivers/i2c/busses/Kconfig       |    7 +
>  drivers/i2c/busses/Makefile      |    1 +
>  drivers/i2c/busses/i2c-exynos5.c |  754 ++++++++++++++++++++++++++++++++++++++

Don't forget you need to document the new compatible string in
Documentation/devicetree/bindings/i2c. That should be part of this
patch.

g.
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Patch

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index bdca511..4caea76 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -618,6 +618,13 @@  config I2C_S3C2410
 	  Say Y here to include support for I2C controller in the
 	  Samsung SoCs.
 
+config I2C_EXYNOS5
+	tristate "Exynos5 high-speed I2C driver"
+	depends on ARCH_EXYNOS5
+	help
+	  Say Y here to include support for High-speed I2C controller in the
+	  Exynos5 based Samsung SoCs.
+
 config I2C_S6000
 	tristate "S6000 I2C support"
 	depends on XTENSA_VARIANT_S6000
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 6181f3f..4b1548c 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -61,6 +61,7 @@  obj-$(CONFIG_I2C_PUV3)		+= i2c-puv3.o
 obj-$(CONFIG_I2C_PXA)		+= i2c-pxa.o
 obj-$(CONFIG_I2C_PXA_PCI)	+= i2c-pxa-pci.o
 obj-$(CONFIG_I2C_S3C2410)	+= i2c-s3c2410.o
+obj-$(CONFIG_I2C_EXYNOS5)	+= i2c-exynos5.o
 obj-$(CONFIG_I2C_S6000)		+= i2c-s6000.o
 obj-$(CONFIG_I2C_SH7760)	+= i2c-sh7760.o
 obj-$(CONFIG_I2C_SH_MOBILE)	+= i2c-sh_mobile.o
diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
new file mode 100644
index 0000000..6bd5637
--- /dev/null
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -0,0 +1,754 @@ 
+/**
+ * i2c-exynos5.c - Samsung Exynos5 I2C Controller Driver
+ *
+ * Copyright (C) 2013 Samsung Electronics Co., Ltd.
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/debugfs.h>
+
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_gpio.h>
+#include <linux/of_irq.h>
+#include <linux/of_i2c.h>
+
+/* Register Map */
+#define HSI2C_CTL		0x00
+#define HSI2C_FIFO_CTL		0x04
+#define HSI2C_TRAILIG_CTL	0x08
+#define HSI2C_CLK_CTL		0x0C
+#define HSI2C_CLK_SLOT		0x10
+#define HSI2C_INT_ENABLE	0x20
+#define HSI2C_INT_STATUS	0x24
+#define HSI2C_ERR_STATUS	0x2C
+#define HSI2C_FIFO_STATUS	0x30
+#define HSI2C_TX_DATA		0x34
+#define HSI2C_RX_DATA		0x38
+#define HSI2C_CONF		0x40
+#define HSI2C_AUTO_CONF		0x44
+#define HSI2C_TIMEOUT		0x48
+#define HSI2C_MANUAL_CMD	0x4C
+#define HSI2C_TRANS_STATUS	0x50
+#define HSI2C_TIMING_HS1	0x54
+#define HSI2C_TIMING_HS2	0x58
+#define HSI2C_TIMING_HS3	0x5C
+#define HSI2C_TIMING_FS1	0x60
+#define HSI2C_TIMING_FS2	0x64
+#define HSI2C_TIMING_FS3	0x68
+#define HSI2C_TIMING_SLA	0x6C
+#define HSI2C_ADDR		0x70
+
+/* I2C_CTL Register bits */
+#define HSI2C_FUNC_MODE_I2C			(1u << 0)
+#define HSI2C_MASTER				(1u << 3)
+#define HSI2C_RXCHON				(1u << 6)
+#define HSI2C_TXCHON				(1u << 7)
+#define HSI2C_SW_RST				(1u << 31)
+
+/* I2C_FIFO_CTL Register bits */
+#define HSI2C_RXFIFO_EN				(1u << 0)
+#define HSI2C_TXFIFO_EN				(1u << 1)
+#define HSI2C_RXFIFO_TRIGGER_LEVEL		(0x20 << 4)
+#define HSI2C_TXFIFO_TRIGGER_LEVEL		(0x20 << 16)
+
+/* I2C_TRAILING_CTL Register bits */
+#define HSI2C_TRAILING_COUNT			(0xf)
+
+/* I2C_INT_EN Register bits */
+#define HSI2C_INT_TX_ALMOSTEMPTY_EN		(1u << 0)
+#define HSI2C_INT_RX_ALMOSTFULL_EN		(1u << 1)
+#define HSI2C_INT_TRAILING_EN			(1u << 6)
+#define HSI2C_INT_I2C_EN			(1u << 9)
+
+/* I2C_FIFO_STAT Register bits */
+#define HSI2C_TX_FIFO_LEVEL_MASK		(0x7 << 7)
+#define HSI2C_TX_FIFO_FULL			(1u << 7)
+#define HSI2C_TX_FIFO_EMPTY			(1u << 8)
+#define HSI2C_RX_FIFO_LEVEL_MASK		(0x7 << 16)
+#define HSI2C_RX_FIFO_FULL			(1u << 23)
+#define HSI2C_RX_FIFO_EMPTY			(1u << 24)
+
+/* I2C_CONF Register bits */
+#define HSI2C_HS_MODE				(1u << 29)
+#define HSI2C_10BIT_ADDR_MODE			(1u << 30)
+#define HSI2C_AUTO_MODE				(1u << 31)
+
+/* I2C_AUTO_CONF Register bits */
+#define HSI2C_READ_WRITE			(1u << 16)
+#define HSI2C_STOP_AFTER_TRANS			(1u << 17)
+#define HSI2C_MASTER_RUN			(1u << 31)
+
+/* I2C_TIMEOUT Register bits */
+#define HSI2C_TIMEOUT_EN			(1u << 31)
+
+/* I2C_TRANS_STATUS register bits */
+#define HSI2C_TRANS_DONE			(1u << 0)
+#define HSI2C_TRANS_ABORT			(1u << 1)
+#define HSI2C_NO_DEV_ACK			(1u << 2)
+#define HSI2C_NO_DEV				(1u << 3)
+#define HSI2C_SLAVE_BUSY			(1u << 16)
+#define HSI2C_MASTER_BUSY			(1u << 17)
+
+/* I2C_ADDR register bits */
+#define HSI2C_SLV_ADDR_SLV(x)			((x & 0x3ff) << 0)
+#define HSI2C_SLV_ADDR_MAS(x)			((x & 0x3ff) << 10)
+#define HSI2C_MASTER_ID(x)			((x & 0xff) << 24)
+
+/**
+ * Although exynos5 supports max HS-IIC speed of 3.4Mhz,
+ * but currently we are facing booting issues beyond 2.5Mhz
+ * So limiting HS-IIC bus speed to 2.5Mhz
+*/
+#define HSI2C_HS_TX_CLOCK	2500000
+#define HSI2C_FS_TX_CLOCK	400000
+#define HSI2C_HIGH_SPD		1
+#define HSI2C_FAST_SPD		0
+
+#define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000))
+
+/* timeout for pm runtime autosuspend */
+#define EXYNOS5_I2C_PM_TIMEOUT		1000	/* ms */
+
+struct exynos5_i2c {
+	struct i2c_adapter	adap;
+	unsigned int		suspended:1;
+
+	struct i2c_msg		*msg;
+	struct completion	msg_complete;
+	unsigned int		msg_ptr;
+
+	unsigned int		irq;
+
+	void __iomem		*regs;
+	struct clk		*clk;
+	struct device		*dev;
+	int			gpios[2];
+	unsigned int		clock;
+
+	int			status;
+	unsigned int		bus_num;
+	int			speed_mode;
+};
+
+static const struct of_device_id exynos5_i2c_match[] = {
+	{ .compatible = "samsung,exynos5-hsi2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, exynos5_i2c_match);
+
+static inline void exynos5_i2c_stop(struct exynos5_i2c *i2c)
+{
+	writel(0, i2c->regs + HSI2C_INT_ENABLE);
+	writel(HSI2C_FUNC_MODE_I2C, i2c->regs + HSI2C_CTL);
+
+	complete(&i2c->msg_complete);
+}
+
+static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c);
+
+static void exynos5_i2c_init(struct exynos5_i2c *i2c)
+{
+	unsigned long i2c_conf = readl(i2c->regs + HSI2C_CONF);
+
+	writel(HSI2C_TRAILING_COUNT, i2c->regs + HSI2C_TRAILIG_CTL);
+
+	/* Configure I2C controller in High speed mode */
+	if (i2c->speed_mode == HSI2C_HIGH_SPD)
+		i2c_conf |= HSI2C_HS_MODE;
+
+	writel(i2c_conf, i2c->regs + HSI2C_CONF);
+
+	exynos5_i2c_set_timing(i2c);
+}
+
+static void exynos5_i2c_reset(struct exynos5_i2c *i2c)
+{
+	unsigned long usi_ctl;
+
+	usi_ctl = readl(i2c->regs + HSI2C_CTL);
+	usi_ctl |= HSI2C_SW_RST;
+	writel(usi_ctl, i2c->regs + HSI2C_CTL);
+
+	usi_ctl = readl(i2c->regs + HSI2C_CTL);
+	usi_ctl &= ~HSI2C_SW_RST;
+	writel(usi_ctl, i2c->regs + HSI2C_CTL);
+
+	exynos5_i2c_init(i2c);
+}
+
+static void exynos5_i2c_en_timeout(struct exynos5_i2c *i2c)
+{
+	unsigned long i2c_timeout = readl(i2c->regs + HSI2C_TIMEOUT);
+
+	/* Clear to enable Timeout */
+	i2c_timeout &= ~HSI2C_TIMEOUT_EN;
+	writel(i2c_timeout, i2c->regs + HSI2C_TIMEOUT);
+}
+
+static void exynos5_i2c_master_run(struct exynos5_i2c *i2c)
+{
+	/* Start data transfer in Master mode */
+	u32 i2c_auto_conf = readl(i2c->regs + HSI2C_AUTO_CONF);
+	i2c_auto_conf |= HSI2C_MASTER_RUN;
+	writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF);
+}
+
+/**
+ * exynos5_i2c_irq: top level IRQ servicing routine
+*/
+static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
+{
+	struct exynos5_i2c *i2c = dev_id;
+	unsigned char byte;
+	u32 t_stat = readl(i2c->regs + HSI2C_TRANS_STATUS);
+
+	i2c->status = -ENXIO;
+	if (t_stat & HSI2C_TRANS_DONE) {
+		i2c->status = 0;
+		if (i2c->msg->flags & I2C_M_RD) {
+			while ((readl(i2c->regs + HSI2C_FIFO_STATUS) &
+				HSI2C_RX_FIFO_FULL) == 0) {
+				byte = (unsigned char)
+					readl(i2c->regs + HSI2C_RX_DATA);
+				i2c->msg->buf[i2c->msg_ptr++] = byte;
+
+				if (i2c->msg->len == 1)
+					break;
+			}
+
+			if (i2c->msg_ptr >= i2c->msg->len)
+				exynos5_i2c_stop(i2c);
+		} else {
+			byte = i2c->msg->buf[i2c->msg_ptr++];
+			writel(byte, i2c->regs + HSI2C_TX_DATA);
+
+			if (i2c->msg_ptr >= i2c->msg->len)
+				exynos5_i2c_stop(i2c);
+		}
+	} else if (t_stat & HSI2C_NO_DEV) {
+		dev_dbg(i2c->dev, "No device found. returning -ENXIO");
+		exynos5_i2c_stop(i2c);
+		goto out;
+	} else if (t_stat & HSI2C_NO_DEV_ACK &&
+			!(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
+		dev_dbg(i2c->dev, "No device Ack. returning -ENXIO");
+		exynos5_i2c_stop(i2c);
+		goto out;
+	} else if (t_stat & HSI2C_TRANS_ABORT) {
+		/* deal with arbitration loss */
+		dev_err(i2c->dev, "deal with arbitration loss\n");
+		exynos5_i2c_stop(i2c);
+		goto out;
+	}
+
+ out:
+	/* Set these bits to clear them */
+	writel(readl(i2c->regs + HSI2C_INT_STATUS),
+				i2c->regs + HSI2C_INT_STATUS);
+	return IRQ_HANDLED;
+}
+
+static void exynos5_i2c_message_start(struct exynos5_i2c *i2c,
+				      struct i2c_msg *msgs, int stop)
+{
+	unsigned long usi_ctl = (HSI2C_FUNC_MODE_I2C | HSI2C_MASTER);
+	unsigned long i2c_auto_conf;
+	unsigned long usi_int_en = HSI2C_INT_I2C_EN;
+	unsigned long usi_fifo_ctl;
+
+	exynos5_i2c_en_timeout(i2c);
+
+	/* Set default trigger level for TXFIFO and RXFIFO */
+	usi_fifo_ctl = HSI2C_TXFIFO_TRIGGER_LEVEL | HSI2C_RXFIFO_TRIGGER_LEVEL;
+	/* Enable RXFIFO and TXFIFO */
+	usi_fifo_ctl |= (HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN);
+	writel(usi_fifo_ctl, i2c->regs + HSI2C_FIFO_CTL);
+
+	if (msgs->flags & I2C_M_RD) {
+		usi_ctl |= HSI2C_RXCHON;
+
+		i2c_auto_conf |= HSI2C_READ_WRITE;
+
+		usi_int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN |
+			HSI2C_INT_TRAILING_EN);
+	} else {
+		usi_ctl |= HSI2C_TXCHON;
+
+		i2c_auto_conf &= ~HSI2C_READ_WRITE;
+
+		usi_int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN;
+	}
+
+	if (stop == 1)
+		i2c_auto_conf |= HSI2C_STOP_AFTER_TRANS;
+	else
+		i2c_auto_conf &= ~HSI2C_STOP_AFTER_TRANS;
+
+	writel(HSI2C_SLV_ADDR_MAS(msgs->addr), i2c->regs + HSI2C_ADDR);
+
+	writel(usi_ctl, i2c->regs + HSI2C_CTL);
+
+	i2c_auto_conf |= i2c->msg->len;
+	writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF);
+
+	exynos5_i2c_master_run(i2c);
+
+	/* Enable appropriate interrupts */
+	writel(usi_int_en, i2c->regs + HSI2C_INT_ENABLE);
+}
+
+static int exynos5_i2c_doxfer(struct exynos5_i2c *i2c,
+				struct i2c_msg *msgs, int stop)
+{
+	unsigned long timeout;
+	unsigned long trans_status;
+	unsigned long usi_fifo_stat;
+	int ret = -EAGAIN;
+
+	if (i2c->suspended) {
+		dev_err(i2c->dev, "HS-I2C is suspended.\n");
+		return -EIO;
+	}
+
+	i2c->msg = msgs;
+	i2c->msg_ptr = 0;
+
+	exynos5_i2c_message_start(i2c, msgs, stop);
+
+	timeout = wait_for_completion_interruptible_timeout
+		(&i2c->msg_complete, EXYNOS5_I2C_TIMEOUT);
+
+	if (i2c->status == -ENXIO) {
+		return i2c->status;
+
+	if (timeout == 0) {
+		exynos5_i2c_reset(i2c);
+		if (msgs->flags & I2C_M_RD) {
+			dev_warn(i2c->dev, "rx timeout\n");
+			ret = 0;
+		} else
+			dev_warn(i2c->dev, "tx timeout\n");
+
+		return ret;
+	}
+
+	timeout = jiffies + timeout;
+	while (time_after(timeout, jiffies)) {
+		usi_fifo_stat = readl(i2c->regs + HSI2C_FIFO_STATUS);
+		trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
+		if ((usi_fifo_stat &
+			(HSI2C_TX_FIFO_EMPTY | HSI2C_RX_FIFO_FULL)) &&
+			((trans_status == 0) || ((stop == 0) &&
+			(trans_status & HSI2C_MASTER_BUSY)))) {
+			ret = 0;
+			break;
+		}
+	}
+
+	if (ret == -EAGAIN) {
+		exynos5_i2c_reset(i2c);
+		dev_warn(i2c->dev, "xfer timeout\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static int exynos5_i2c_xfer(struct i2c_adapter *adap,
+			struct i2c_msg *msgs, int num)
+{
+	struct exynos5_i2c *i2c = (struct exynos5_i2c *)adap->algo_data;
+	int retry, i;
+	int ret;
+	int stop = 0;
+	struct i2c_msg *msgs_ptr = msgs;
+
+	ret = pm_runtime_get_sync(i2c->dev);
+	if (IS_ERR_VALUE(ret))
+		goto out;
+
+	clk_prepare_enable(i2c->clk);
+
+	for (retry = 0; retry < adap->retries; retry++) {
+		for (i = 0; i < num; i++) {
+			if (i == num - 1)
+				stop = 1;
+			ret = exynos5_i2c_doxfer(i2c, msgs, stop);
+			msgs_ptr++;
+
+			if (ret == -EAGAIN) {
+				msgs_ptr = msgs;
+				stop = 0;
+				break;
+			}
+		}
+
+		if (i == num) {
+			if (ret != -ENXIO)
+				ret = num;
+			goto out;
+
+		}
+
+		dev_dbg(i2c->dev, "retrying transfer (%d)\n", retry);
+
+		udelay(100);
+	}
+
+	ret = -EREMOTEIO;
+ out:
+	clk_disable_unprepare(i2c->clk);
+
+	pm_runtime_mark_last_busy(i2c->dev);
+	pm_runtime_put_autosuspend(i2c->dev);
+	return ret;
+}
+
+static u32 exynos5_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm exynos5_i2c_algorithm = {
+	.master_xfer		= exynos5_i2c_xfer,
+	.functionality		= exynos5_i2c_func,
+};
+
+static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c)
+{
+	unsigned long i2c_timing_s1;
+	unsigned long i2c_timing_s2;
+	unsigned long i2c_timing_s3;
+	unsigned long i2c_timing_sla;
+	unsigned int op_clk = i2c->clock;
+	unsigned int clkin = clk_get_rate(i2c->clk);
+	unsigned int n_clkdiv;
+	unsigned int t_start_su, t_start_hd;
+	unsigned int t_stop_su;
+	unsigned int t_data_su, t_data_hd;
+	unsigned int t_scl_l, t_scl_h;
+	unsigned int t_sr_release;
+	unsigned int t_ftl_cycle;
+	unsigned int i = 0, utemp0 = 0, utemp1 = 0, utemp2 = 0;
+
+	/* FPCLK / FI2C =
+	 * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE
+	 * uTemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2)
+	 * uTemp1 = (TSCLK_L + TSCLK_H + 2)
+	 * uTemp2 = TSCLK_L + TSCLK_H
+	*/
+	t_ftl_cycle = (readl(i2c->regs + HSI2C_CONF) >> 16) & 0x7;
+	utemp0 = (clkin / op_clk) - 8 - 2 * t_ftl_cycle;
+
+	/* CLK_DIV max is 256 */
+	for (i = 0; i < 256; i++) {
+		utemp1 = utemp0 / (i + 1);
+		/* SCLK_L/H max is 256 / 2 */
+		if (utemp1 < 128) {
+			utemp2 = utemp1 - 2;
+			break;
+		}
+	}
+
+	n_clkdiv = i;
+	t_scl_l = utemp2 / 2;
+	t_scl_h = utemp2 / 2;
+	t_start_su = t_scl_l;
+	t_start_hd = t_scl_l;
+	t_stop_su = t_scl_l;
+	t_data_su = t_scl_l / 2;
+	t_data_hd = t_scl_l / 2;
+	t_sr_release = utemp2;
+
+	i2c_timing_s1 = t_start_su << 24 | t_start_hd << 16 | t_stop_su << 8;
+	i2c_timing_s2 = t_data_su << 24 | t_scl_l << 8 | t_scl_h << 0;
+	i2c_timing_s3 = n_clkdiv << 16 | t_sr_release << 0;
+	i2c_timing_sla = t_data_hd << 0;
+
+	dev_dbg(i2c->dev, "tSTART_SU: %X, tSTART_HD: %X, tSTOP_SU: %X\n",
+		t_start_su, t_start_hd, t_stop_su);
+	dev_dbg(i2c->dev, "tDATA_SU: %X, tSCL_L: %X, tSCL_H: %X\n",
+		t_data_su, t_scl_l, t_scl_h);
+	dev_dbg(i2c->dev, "nClkDiv: %X, tSR_RELEASE: %X\n",
+		n_clkdiv, t_sr_release);
+	dev_dbg(i2c->dev, "tDATA_HD: %X\n", t_data_hd);
+
+	if (i2c->speed_mode == HSI2C_HIGH_SPD) {
+		writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_HS1);
+		writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_HS2);
+		writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_HS3);
+	} else {
+		writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_FS1);
+		writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_FS2);
+		writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_FS3);
+	}
+	writel(i2c_timing_sla, i2c->regs + HSI2C_TIMING_SLA);
+
+	return 0;
+}
+
+/**
+ * Parse a list of GPIOs from a node property and request each one
+ *
+ * @param i2c		i2c driver data
+ * @return 0 on success, -EINVAL on error, in which case no GPIOs requested
+*/
+static int exynos5_i2c_parse_dt_gpio(struct exynos5_i2c *i2c)
+{
+	int idx, gpio, ret;
+
+	for (idx = 0; idx < 2; idx++) {
+		gpio = of_get_gpio(i2c->dev->of_node, idx);
+		if (!gpio_is_valid(gpio)) {
+			dev_err(i2c->dev, "invalid gpio[%d]: %d\n", idx, gpio);
+			return -EINVAL;
+		}
+		i2c->gpios[idx] = gpio;
+
+		ret = devm_gpio_request(i2c->dev, gpio, "i2c-bus");
+		if (ret) {
+			dev_err(i2c->dev, "gpio [%d] request failed\n", gpio);
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+
+#define HSI2C_REG(regname) {.name = #regname, .offset = regname}
+static struct debugfs_reg32 exynos5_hsi2c_regs[] = {
+	HSI2C_REG(HSI2C_CTL), HSI2C_REG(HSI2C_FIFO_CTL),
+	HSI2C_REG(HSI2C_TRAILIG_CTL), HSI2C_REG(HSI2C_CLK_CTL),
+	HSI2C_REG(HSI2C_CLK_SLOT), HSI2C_REG(HSI2C_INT_ENABLE),
+	HSI2C_REG(HSI2C_INT_STATUS), HSI2C_REG(HSI2C_ERR_STATUS),
+	HSI2C_REG(HSI2C_FIFO_STATUS), HSI2C_REG(HSI2C_TX_DATA),
+	HSI2C_REG(HSI2C_RX_DATA), HSI2C_REG(HSI2C_CONF),
+	HSI2C_REG(HSI2C_AUTO_CONF), HSI2C_REG(HSI2C_TIMEOUT),
+	HSI2C_REG(HSI2C_MANUAL_CMD), HSI2C_REG(HSI2C_TRANS_STATUS),
+	HSI2C_REG(HSI2C_TIMING_HS1), HSI2C_REG(HSI2C_TIMING_HS2),
+	HSI2C_REG(HSI2C_TIMING_HS3), HSI2C_REG(HSI2C_TIMING_FS1),
+	HSI2C_REG(HSI2C_TIMING_FS2), HSI2C_REG(HSI2C_TIMING_FS3),
+	HSI2C_REG(HSI2C_TIMING_SLA), HSI2C_REG(HSI2C_ADDR),
+};
+
+static struct debugfs_regset32 exynos5_hsi2c_regset = {
+	.regs = exynos5_hsi2c_regs,
+	.nregs = ARRAY_SIZE(exynos5_hsi2c_regs),
+};
+
+static struct dentry *exynos5_hsi2c_reg_debugfs;
+
+static int exynos5_i2c_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct exynos5_i2c *i2c;
+	int ret;
+
+	if (!np) {
+		dev_err(&pdev->dev, "no device node\n");
+		return -ENOENT;
+	}
+
+	i2c = devm_kzalloc(&pdev->dev, sizeof(struct exynos5_i2c), GFP_KERNEL);
+	if (!i2c) {
+		dev_err(&pdev->dev, "no memory for state\n");
+		return -ENOMEM;
+	}
+
+	i2c->bus_num = -1;
+
+	/* Mode of operation High/Fast Speed mode */
+	if (!of_property_read_u32(np, "samsung,hs-mode", &i2c->speed_mode)) {
+		if (of_property_read_u32(np, "samsung,hs-clock", &i2c->clock))
+			i2c->clock = HSI2C_HS_TX_CLOCK;
+	} else {
+		if (of_property_read_u32(np, "samsung,fs-clock", &i2c->clock))
+			i2c->clock = HSI2C_FS_TX_CLOCK;
+	}
+
+	strlcpy(i2c->adap.name, "exynos5-i2c", sizeof(i2c->adap.name));
+	i2c->adap.owner   = THIS_MODULE;
+	i2c->adap.algo    = &exynos5_i2c_algorithm;
+	i2c->adap.retries = 2;
+	i2c->adap.class   = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+
+	i2c->dev = &pdev->dev;
+	i2c->clk = devm_clk_get(&pdev->dev, "hsi2c");
+	if (IS_ERR(i2c->clk)) {
+		dev_err(&pdev->dev, "cannot get HS-I2C clock\n");
+		ret = -ENOENT;
+		goto err_noclk;
+	}
+
+	dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk);
+
+	clk_prepare_enable(i2c->clk);
+
+	i2c->regs = of_iomap(np, 0);
+	if (!i2c->regs) {
+		dev_err(&pdev->dev, "cannot map HS-I2C IO\n");
+		ret = -ENXIO;
+		goto err_clk;
+	}
+
+	/* parse device tree and inititalise the gpio */
+	if (exynos5_i2c_parse_dt_gpio(i2c))
+		return -EINVAL;
+
+	i2c->irq = irq_of_parse_and_map(np, 0);
+	if (i2c->irq) {
+		ret = devm_request_irq(&pdev->dev, i2c->irq, exynos5_i2c_irq,
+				0, dev_name(&pdev->dev), i2c);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n",
+								i2c->irq);
+			goto err_iomap;
+		}
+	}
+
+	/*
+	 * TODO: Use private lock to avoid race conditions as
+	 * mentioned in pm_runtime.txt
+	 */
+	pm_runtime_enable(i2c->dev);
+	pm_runtime_set_autosuspend_delay(i2c->dev, EXYNOS5_I2C_PM_TIMEOUT);
+	pm_runtime_use_autosuspend(i2c->dev);
+
+	ret = pm_runtime_get_sync(i2c->dev);
+	if (IS_ERR_VALUE(ret))
+		goto err_iomap;
+
+	exynos5_i2c_init(i2c);
+
+	i2c->adap.algo_data = i2c;
+	i2c->adap.dev.parent = &pdev->dev;
+	i2c->adap.nr = i2c->bus_num;
+	i2c->adap.dev.of_node = np;
+
+	ret = i2c_add_numbered_adapter(&i2c->adap);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to add bus to i2c core\n");
+		goto err_pm;
+	}
+
+	init_completion(&i2c->msg_complete);
+	of_i2c_register_devices(&i2c->adap);
+	platform_set_drvdata(pdev, i2c);
+
+	exynos5_hsi2c_reg_debugfs = debugfs_create_regset32("exynos5-hsi2c",
+						  S_IFREG | S_IRUGO,
+						  NULL, &exynos5_hsi2c_regset);
+	clk_disable_unprepare(i2c->clk);
+	pm_runtime_mark_last_busy(i2c->dev);
+	pm_runtime_put_autosuspend(i2c->dev);
+	return 0;
+
+ err_pm:
+	pm_runtime_put(i2c->dev);
+	pm_runtime_disable(&pdev->dev);
+ err_iomap:
+	iounmap(i2c->regs);
+ err_clk:
+	clk_disable_unprepare(i2c->clk);
+ err_noclk:
+	return ret;
+}
+
+static int exynos5_i2c_remove(struct platform_device *pdev)
+{
+	struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (IS_ERR_VALUE(ret))
+		return ret;
+
+	clk_disable_unprepare(i2c->clk);
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	i2c_del_adapter(&i2c->adap);
+
+	iounmap(i2c->regs);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int exynos5_i2c_suspend_noirq(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
+
+	i2c->suspended = 1;
+
+	return 0;
+}
+
+static int exynos5_i2c_resume_noirq(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
+
+	clk_prepare_enable(i2c->clk);
+	exynos5_i2c_init(i2c);
+	clk_disable_unprepare(i2c->clk);
+	i2c->suspended = 0;
+
+	return 0;
+}
+
+static const struct dev_pm_ops exynos5_i2c_dev_pm_ops = {
+	.suspend_noirq	= exynos5_i2c_suspend_noirq,
+	.resume_noirq	= exynos5_i2c_resume_noirq,
+};
+
+#define EXYNOS5_DEV_PM_OPS (&exynos5_i2c_dev_pm_ops)
+#else
+#define EXYNOS5_DEV_PM_OPS NULL
+#endif
+
+static struct platform_driver exynos5_i2c_driver = {
+	.probe		= exynos5_i2c_probe,
+	.remove		= exynos5_i2c_remove,
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= "exynos5-hsi2c",
+		.pm	= EXYNOS5_DEV_PM_OPS,
+		.of_match_table = of_match_ptr(exynos5_i2c_match),
+	},
+};
+
+static int __init i2c_adap_exynos5_init(void)
+{
+	return platform_driver_register(&exynos5_i2c_driver);
+}
+subsys_initcall(i2c_adap_exynos5_init);
+
+static void __exit i2c_adap_exynos5_exit(void)
+{
+	platform_driver_unregister(&exynos5_i2c_driver);
+}
+module_exit(i2c_adap_exynos5_exit);
+
+MODULE_DESCRIPTION("Exynos5 HS-I2C Bus driver");
+MODULE_AUTHOR("Naveen Krishna Chatradhi, <ch.naveen@samsung.com>");
+MODULE_AUTHOR("Taekgyun Ko, <taeggyun.ko@samsung.com>");
+MODULE_LICENSE("GPL");