Merge branch 'next-i2c' of git://aeryn.fluff.org.uk/bjdooks/linux

* 'next-i2c' of git://aeryn.fluff.org.uk/bjdooks/linux:
  i2c: driver for the Synopsys DesignWare I2C controller

3 files changed, 634 insertions, 0 deletions

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 3c259ee7ddda..aa87b6a3bbef 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -326,6 +326,15 @@ config I2C_DAVINCI
 	  devices such as DaVinci NIC.
 	  For details please see http://www.ti.com/davinci
 
+config I2C_DESIGNWARE
+	tristate "Synopsys DesignWare"
+	help
+	  If you say yes to this option, support will be included for the
+	  Synopsys DesignWare I2C adapter. Only master mode is supported.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-designware.
+
 config I2C_GPIO
 	tristate "GPIO-based bitbanging I2C"
 	depends on GENERIC_GPIO
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index edeabf003106..e654263bfc01 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_I2C_AU1550)	+= i2c-au1550.o
 obj-$(CONFIG_I2C_BLACKFIN_TWI)	+= i2c-bfin-twi.o
 obj-$(CONFIG_I2C_CPM)		+= i2c-cpm.o
 obj-$(CONFIG_I2C_DAVINCI)	+= i2c-davinci.o
+obj-$(CONFIG_I2C_DESIGNWARE)	+= i2c-designware.o
 obj-$(CONFIG_I2C_GPIO)		+= i2c-gpio.o
 obj-$(CONFIG_I2C_HIGHLANDER)	+= i2c-highlander.o
 obj-$(CONFIG_I2C_IBM_IIC)	+= i2c-ibm_iic.o
diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c
new file mode 100644
index 000000000000..b444762e9b9f
--- /dev/null
+++ b/drivers/i2c/busses/i2c-designware.c
@@ -0,0 +1,624 @@
+/*
+ * Synopsys Designware I2C adapter driver (master only).
+ *
+ * Based on the TI DAVINCI I2C adapter driver.
+ *
+ * Copyright (C) 2006 Texas Instruments.
+ * Copyright (C) 2007 MontaVista Software Inc.
+ * Copyright (C) 2009 Provigent Ltd.
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * ----------------------------------------------------------------------------
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+/*
+ * Registers offset
+ */
+#define DW_IC_CON		0x0
+#define DW_IC_TAR		0x4
+#define DW_IC_DATA_CMD		0x10
+#define DW_IC_SS_SCL_HCNT	0x14
+#define DW_IC_SS_SCL_LCNT	0x18
+#define DW_IC_FS_SCL_HCNT	0x1c
+#define DW_IC_FS_SCL_LCNT	0x20
+#define DW_IC_INTR_STAT		0x2c
+#define DW_IC_INTR_MASK		0x30
+#define DW_IC_CLR_INTR		0x40
+#define DW_IC_ENABLE		0x6c
+#define DW_IC_STATUS		0x70
+#define DW_IC_TXFLR		0x74
+#define DW_IC_RXFLR		0x78
+#define DW_IC_COMP_PARAM_1	0xf4
+#define DW_IC_TX_ABRT_SOURCE	0x80
+
+#define DW_IC_CON_MASTER		0x1
+#define DW_IC_CON_SPEED_STD		0x2
+#define DW_IC_CON_SPEED_FAST		0x4
+#define DW_IC_CON_10BITADDR_MASTER	0x10
+#define DW_IC_CON_RESTART_EN		0x20
+#define DW_IC_CON_SLAVE_DISABLE		0x40
+
+#define DW_IC_INTR_TX_EMPTY	0x10
+#define DW_IC_INTR_TX_ABRT	0x40
+#define DW_IC_INTR_STOP_DET	0x200
+
+#define DW_IC_STATUS_ACTIVITY	0x1
+
+#define DW_IC_ERR_TX_ABRT	0x1
+
+/*
+ * status codes
+ */
+#define STATUS_IDLE			0x0
+#define STATUS_WRITE_IN_PROGRESS	0x1
+#define STATUS_READ_IN_PROGRESS		0x2
+
+#define TIMEOUT			20 /* ms */
+
+/*
+ * hardware abort codes from the DW_IC_TX_ABRT_SOURCE register
+ *
+ * only expected abort codes are listed here
+ * refer to the datasheet for the full list
+ */
+#define ABRT_7B_ADDR_NOACK	0
+#define ABRT_10ADDR1_NOACK	1
+#define ABRT_10ADDR2_NOACK	2
+#define ABRT_TXDATA_NOACK	3
+#define ABRT_GCALL_NOACK	4
+#define ABRT_GCALL_READ		5
+#define ABRT_SBYTE_ACKDET	7
+#define ABRT_SBYTE_NORSTRT	9
+#define ABRT_10B_RD_NORSTRT	10
+#define ARB_MASTER_DIS		11
+#define ARB_LOST		12
+
+static char *abort_sources[] = {
+	[ABRT_7B_ADDR_NOACK]	=
+		"slave address not acknowledged (7bit mode)",
+	[ABRT_10ADDR1_NOACK]	=
+		"first address byte not acknowledged (10bit mode)",
+	[ABRT_10ADDR2_NOACK]	=
+		"second address byte not acknowledged (10bit mode)",
+	[ABRT_TXDATA_NOACK]		=
+		"data not acknowledged",
+	[ABRT_GCALL_NOACK]		=
+		"no acknowledgement for a general call",
+	[ABRT_GCALL_READ]		=
+		"read after general call",
+	[ABRT_SBYTE_ACKDET]		=
+		"start byte acknowledged",
+	[ABRT_SBYTE_NORSTRT]	=
+		"trying to send start byte when restart is disabled",
+	[ABRT_10B_RD_NORSTRT]	=
+		"trying to read when restart is disabled (10bit mode)",
+	[ARB_MASTER_DIS]		=
+		"trying to use disabled adapter",
+	[ARB_LOST]			=
+		"lost arbitration",
+};
+
+/**
+ * struct dw_i2c_dev - private i2c-designware data
+ * @dev: driver model device node
+ * @base: IO registers pointer
+ * @cmd_complete: tx completion indicator
+ * @pump_msg: continue in progress transfers
+ * @lock: protect this struct and IO registers
+ * @clk: input reference clock
+ * @cmd_err: run time hadware error code
+ * @msgs: points to an array of messages currently being transfered
+ * @msgs_num: the number of elements in msgs
+ * @msg_write_idx: the element index of the current tx message in the msgs
+ *	array
+ * @tx_buf_len: the length of the current tx buffer
+ * @tx_buf: the current tx buffer
+ * @msg_read_idx: the element index of the current rx message in the msgs
+ *	array
+ * @rx_buf_len: the length of the current rx buffer
+ * @rx_buf: the current rx buffer
+ * @msg_err: error status of the current transfer
+ * @status: i2c master status, one of STATUS_*
+ * @abort_source: copy of the TX_ABRT_SOURCE register
+ * @irq: interrupt number for the i2c master
+ * @adapter: i2c subsystem adapter node
+ * @tx_fifo_depth: depth of the hardware tx fifo
+ * @rx_fifo_depth: depth of the hardware rx fifo
+ */
+struct dw_i2c_dev {
+	struct device		*dev;
+	void __iomem		*base;
+	struct completion	cmd_complete;
+	struct tasklet_struct	pump_msg;
+	struct mutex		lock;
+	struct clk		*clk;
+	int			cmd_err;
+	struct i2c_msg		*msgs;
+	int			msgs_num;
+	int			msg_write_idx;
+	u16			tx_buf_len;
+	u8			*tx_buf;
+	int			msg_read_idx;
+	u16			rx_buf_len;
+	u8			*rx_buf;
+	int			msg_err;
+	unsigned int		status;
+	u16			abort_source;
+	int			irq;
+	struct i2c_adapter	adapter;
+	unsigned int		tx_fifo_depth;
+	unsigned int		rx_fifo_depth;
+};
+
+/**
+ * i2c_dw_init() - initialize the designware i2c master hardware
+ * @dev: device private data
+ *
+ * This functions configures and enables the I2C master.
+ * This function is called during I2C init function, and in case of timeout at
+ * run time.
+ */
+static void i2c_dw_init(struct dw_i2c_dev *dev)
+{
+	u32 input_clock_khz = clk_get_rate(dev->clk) / 1000;
+	u16 ic_con;
+
+	/* Disable the adapter */
+	writeb(0, dev->base + DW_IC_ENABLE);
+
+	/* set standard and fast speed deviders for high/low periods */
+	writew((input_clock_khz * 40 / 10000)+1, /* std speed high, 4us */
+			dev->base + DW_IC_SS_SCL_HCNT);
+	writew((input_clock_khz * 47 / 10000)+1, /* std speed low, 4.7us */
+			dev->base + DW_IC_SS_SCL_LCNT);
+	writew((input_clock_khz *  6 / 10000)+1, /* fast speed high, 0.6us */
+			dev->base + DW_IC_FS_SCL_HCNT);
+	writew((input_clock_khz * 13 / 10000)+1, /* fast speed low, 1.3us */
+			dev->base + DW_IC_FS_SCL_LCNT);
+
+	/* configure the i2c master */
+	ic_con = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
+		DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
+	writew(ic_con, dev->base + DW_IC_CON);
+}
+
+/*
+ * Waiting for bus not busy
+ */
+static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
+{
+	int timeout = TIMEOUT;
+
+	while (readb(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
+		if (timeout <= 0) {
+			dev_warn(dev->dev, "timeout waiting for bus ready\n");
+			return -ETIMEDOUT;
+		}
+		timeout--;
+		mdelay(1);
+	}
+
+	return 0;
+}
+
+/*
+ * Initiate low level master read/write transaction.
+ * This function is called from i2c_dw_xfer when starting a transfer.
+ * This function is also called from dw_i2c_pump_msg to continue a transfer
+ * that is longer than the size of the TX FIFO.
+ */
+static void
+i2c_dw_xfer_msg(struct i2c_adapter *adap)
+{
+	struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+	struct i2c_msg *msgs = dev->msgs;
+	int num = dev->msgs_num;
+	u16 ic_con, intr_mask;
+	int tx_limit = dev->tx_fifo_depth - readb(dev->base + DW_IC_TXFLR);
+	int rx_limit = dev->rx_fifo_depth - readb(dev->base + DW_IC_RXFLR);
+	u16 addr = msgs[dev->msg_write_idx].addr;
+	u16 buf_len = dev->tx_buf_len;
+
+	if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
+		/* Disable the adapter */
+		writeb(0, dev->base + DW_IC_ENABLE);
+
+		/* set the slave (target) address */
+		writew(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR);
+
+		/* if the slave address is ten bit address, enable 10BITADDR */
+		ic_con = readw(dev->base + DW_IC_CON);
+		if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
+			ic_con |= DW_IC_CON_10BITADDR_MASTER;
+		else
+			ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
+		writew(ic_con, dev->base + DW_IC_CON);
+
+		/* Enable the adapter */
+		writeb(1, dev->base + DW_IC_ENABLE);
+	}
+
+	for (; dev->msg_write_idx < num; dev->msg_write_idx++) {
+		/* if target address has changed, we need to
+		 * reprogram the target address in the i2c
+		 * adapter when we are done with this transfer
+		 */
+		if (msgs[dev->msg_write_idx].addr != addr)
+			return;
+
+		if (msgs[dev->msg_write_idx].len == 0) {
+			dev_err(dev->dev,
+				"%s: invalid message length\n", __func__);
+			dev->msg_err = -EINVAL;
+			return;
+		}
+
+		if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
+			/* new i2c_msg */
+			dev->tx_buf = msgs[dev->msg_write_idx].buf;
+			buf_len = msgs[dev->msg_write_idx].len;
+		}
+
+		while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
+			if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
+				writew(0x100, dev->base + DW_IC_DATA_CMD);
+				rx_limit--;
+			} else
+				writew(*(dev->tx_buf++),
+						dev->base + DW_IC_DATA_CMD);
+			tx_limit--; buf_len--;
+		}
+	}
+
+	intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
+	if (buf_len > 0) { /* more bytes to be written */
+		intr_mask |= DW_IC_INTR_TX_EMPTY;
+		dev->status |= STATUS_WRITE_IN_PROGRESS;
+	} else
+		dev->status &= ~STATUS_WRITE_IN_PROGRESS;
+	writew(intr_mask, dev->base + DW_IC_INTR_MASK);
+
+	dev->tx_buf_len = buf_len;
+}
+
+static void
+i2c_dw_read(struct i2c_adapter *adap)
+{
+	struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+	struct i2c_msg *msgs = dev->msgs;
+	int num = dev->msgs_num;
+	u16 addr = msgs[dev->msg_read_idx].addr;
+	int rx_valid = readw(dev->base + DW_IC_RXFLR);
+
+	for (; dev->msg_read_idx < num; dev->msg_read_idx++) {
+		u16 len;
+		u8 *buf;
+
+		if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
+			continue;
+
+		/* different i2c client, reprogram the i2c adapter */
+		if (msgs[dev->msg_read_idx].addr != addr)
+			return;
+
+		if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
+			len = msgs[dev->msg_read_idx].len;
+			buf = msgs[dev->msg_read_idx].buf;
+		} else {
+			len = dev->rx_buf_len;
+			buf = dev->rx_buf;
+		}
+
+		for (; len > 0 && rx_valid > 0; len--, rx_valid--)
+			*buf++ = readb(dev->base + DW_IC_DATA_CMD);
+
+		if (len > 0) {
+			dev->status |= STATUS_READ_IN_PROGRESS;
+			dev->rx_buf_len = len;
+			dev->rx_buf = buf;
+			return;
+		} else
+			dev->status &= ~STATUS_READ_IN_PROGRESS;
+	}
+}
+
+/*
+ * Prepare controller for a transaction and call i2c_dw_xfer_msg
+ */
+static int
+i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+	struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+	int ret;
+
+	dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
+
+	mutex_lock(&dev->lock);
+
+	INIT_COMPLETION(dev->cmd_complete);
+	dev->msgs = msgs;
+	dev->msgs_num = num;
+	dev->cmd_err = 0;
+	dev->msg_write_idx = 0;
+	dev->msg_read_idx = 0;
+	dev->msg_err = 0;
+	dev->status = STATUS_IDLE;
+
+	ret = i2c_dw_wait_bus_not_busy(dev);
+	if (ret < 0)
+		goto done;
+
+	/* start the transfers */
+	i2c_dw_xfer_msg(adap);
+
+	/* wait for tx to complete */
+	ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);
+	if (ret == 0) {
+		dev_err(dev->dev, "controller timed out\n");
+		i2c_dw_init(dev);
+		ret = -ETIMEDOUT;
+		goto done;
+	} else if (ret < 0)
+		goto done;
+
+	if (dev->msg_err) {
+		ret = dev->msg_err;
+		goto done;
+	}
+
+	/* no error */
+	if (likely(!dev->cmd_err)) {
+		/* read rx fifo, and disable the adapter */
+		do {
+			i2c_dw_read(adap);
+		} while (dev->status & STATUS_READ_IN_PROGRESS);
+		writeb(0, dev->base + DW_IC_ENABLE);
+		ret = num;
+		goto done;
+	}
+
+	/* We have an error */
+	if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
+		unsigned long abort_source = dev->abort_source;
+		int i;
+
+		for_each_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) {
+		    dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
+		}
+	}
+	ret = -EIO;
+
+done:
+	mutex_unlock(&dev->lock);
+
+	return ret;
+}
+
+static u32 i2c_dw_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
+}
+
+static void dw_i2c_pump_msg(unsigned long data)
+{
+	struct dw_i2c_dev *dev = (struct dw_i2c_dev *) data;
+	u16 intr_mask;
+
+	i2c_dw_read(&dev->adapter);
+	i2c_dw_xfer_msg(&dev->adapter);
+
+	intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
+	if (dev->status & STATUS_WRITE_IN_PROGRESS)
+		intr_mask |= DW_IC_INTR_TX_EMPTY;
+	writew(intr_mask, dev->base + DW_IC_INTR_MASK);
+}
+
+/*
+ * Interrupt service routine. This gets called whenever an I2C interrupt
+ * occurs.
+ */
+static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
+{
+	struct dw_i2c_dev *dev = dev_id;
+	u16 stat;
+
+	stat = readw(dev->base + DW_IC_INTR_STAT);
+	dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
+	if (stat & DW_IC_INTR_TX_ABRT) {
+		dev->abort_source = readw(dev->base + DW_IC_TX_ABRT_SOURCE);
+		dev->cmd_err |= DW_IC_ERR_TX_ABRT;
+		dev->status = STATUS_IDLE;
+	} else if (stat & DW_IC_INTR_TX_EMPTY)
+		tasklet_schedule(&dev->pump_msg);
+
+	readb(dev->base + DW_IC_CLR_INTR);	/* clear interrupts */
+	writew(0, dev->base + DW_IC_INTR_MASK);	/* disable interrupts */
+	if (stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET))
+		complete(&dev->cmd_complete);
+
+	return IRQ_HANDLED;
+}
+
+static struct i2c_algorithm i2c_dw_algo = {
+	.master_xfer	= i2c_dw_xfer,
+	.functionality	= i2c_dw_func,
+};
+
+static int __devinit dw_i2c_probe(struct platform_device *pdev)
+{
+	struct dw_i2c_dev *dev;
+	struct i2c_adapter *adap;
+	struct resource *mem, *irq, *ioarea;
+	int r;
+
+	/* NOTE: driver uses the static register mapping */
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem) {
+		dev_err(&pdev->dev, "no mem resource?\n");
+		return -EINVAL;
+	}
+
+	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!irq) {
+		dev_err(&pdev->dev, "no irq resource?\n");
+		return -EINVAL;
+	}
+
+	ioarea = request_mem_region(mem->start, resource_size(mem),
+			pdev->name);
+	if (!ioarea) {
+		dev_err(&pdev->dev, "I2C region already claimed\n");
+		return -EBUSY;
+	}
+
+	dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
+	if (!dev) {
+		r = -ENOMEM;
+		goto err_release_region;
+	}
+
+	init_completion(&dev->cmd_complete);
+	tasklet_init(&dev->pump_msg, dw_i2c_pump_msg, (unsigned long) dev);
+	mutex_init(&dev->lock);
+	dev->dev = get_device(&pdev->dev);
+	dev->irq = irq->start;
+	platform_set_drvdata(pdev, dev);
+
+	dev->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(dev->clk)) {
+		r = -ENODEV;
+		goto err_free_mem;
+	}
+	clk_enable(dev->clk);
+
+	dev->base = ioremap(mem->start, resource_size(mem));
+	if (dev->base == NULL) {
+		dev_err(&pdev->dev, "failure mapping io resources\n");
+		r = -EBUSY;
+		goto err_unuse_clocks;
+	}
+	{
+		u32 param1 = readl(dev->base + DW_IC_COMP_PARAM_1);
+
+		dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
+		dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
+	}
+	i2c_dw_init(dev);
+
+	writew(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
+	r = request_irq(dev->irq, i2c_dw_isr, 0, pdev->name, dev);
+	if (r) {
+		dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
+		goto err_iounmap;
+	}
+
+	adap = &dev->adapter;
+	i2c_set_adapdata(adap, dev);
+	adap->owner = THIS_MODULE;
+	adap->class = I2C_CLASS_HWMON;
+	strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
+			sizeof(adap->name));
+	adap->algo = &i2c_dw_algo;
+	adap->dev.parent = &pdev->dev;
+
+	adap->nr = pdev->id;
+	r = i2c_add_numbered_adapter(adap);
+	if (r) {
+		dev_err(&pdev->dev, "failure adding adapter\n");
+		goto err_free_irq;
+	}
+
+	return 0;
+
+err_free_irq:
+	free_irq(dev->irq, dev);
+err_iounmap:
+	iounmap(dev->base);
+err_unuse_clocks:
+	clk_disable(dev->clk);
+	clk_put(dev->clk);
+	dev->clk = NULL;
+err_free_mem:
+	platform_set_drvdata(pdev, NULL);
+	put_device(&pdev->dev);
+	kfree(dev);
+err_release_region:
+	release_mem_region(mem->start, resource_size(mem));
+
+	return r;
+}
+
+static int __devexit dw_i2c_remove(struct platform_device *pdev)
+{
+	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
+	struct resource *mem;
+
+	platform_set_drvdata(pdev, NULL);
+	i2c_del_adapter(&dev->adapter);
+	put_device(&pdev->dev);
+
+	clk_disable(dev->clk);
+	clk_put(dev->clk);
+	dev->clk = NULL;
+
+	writeb(0, dev->base + DW_IC_ENABLE);
+	free_irq(dev->irq, dev);
+	kfree(dev);
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	release_mem_region(mem->start, resource_size(mem));
+	return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:i2c_designware");
+
+static struct platform_driver dw_i2c_driver = {
+	.remove		= __devexit_p(dw_i2c_remove),
+	.driver		= {
+		.name	= "i2c_designware",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init dw_i2c_init_driver(void)
+{
+	return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
+}
+module_init(dw_i2c_init_driver);
+
+static void __exit dw_i2c_exit_driver(void)
+{
+	platform_driver_unregister(&dw_i2c_driver);
+}
+module_exit(dw_i2c_exit_driver);
+
+MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
+MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
+MODULE_LICENSE("GPL");