i2c: iMX/MXC support
authorDarius Augulis <augulis.darius@gmail.com>
Fri, 30 Jan 2009 08:32:28 +0000 (10:32 +0200)
committerBen Dooks <ben-linux@fluff.org>
Tue, 7 Apr 2009 09:18:32 +0000 (10:18 +0100)
Implementation of I2C Adapter/Algorithm Driver for I2C Bus integrated
in Freescale's i.MX/MXC processors.

Signed-off-by: Darius Augulis <augulis.darius@gmail.com>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
arch/arm/plat-mxc/include/mach/i2c.h [new file with mode: 0644]
drivers/i2c/busses/Kconfig
drivers/i2c/busses/Makefile
drivers/i2c/busses/i2c-imx.c [new file with mode: 0644]

diff --git a/arch/arm/plat-mxc/include/mach/i2c.h b/arch/arm/plat-mxc/include/mach/i2c.h
new file mode 100644 (file)
index 0000000..4a5dc5c
--- /dev/null
@@ -0,0 +1,25 @@
+/*
+ * i2c.h - i.MX I2C driver header file
+ *
+ * Copyright (c) 2008, Darius Augulis <augulis.darius@gmail.com>
+ *
+ * This file is released under the GPLv2
+ */
+
+#ifndef __ASM_ARCH_I2C_H_
+#define __ASM_ARCH_I2C_H_
+
+/**
+ * struct imxi2c_platform_data - structure of platform data for MXC I2C driver
+ * @init:      Initialise gpio's and other board specific things
+ * @exit:      Free everything initialised by @init
+ * @bitrate:   Bus speed measured in Hz
+ *
+ **/
+struct imxi2c_platform_data {
+       int (*init)(struct device *dev);
+       void (*exit)(struct device *dev);
+       int bitrate;
+};
+
+#endif /* __ASM_ARCH_I2C_H_ */
index da809ad0996aaa1ea010a13900fa466be9e92ec0..5d4aa5e873cac53075248c283a411523ab37d9ac 100644 (file)
@@ -356,6 +356,16 @@ config I2C_IBM_IIC
          This driver can also be built as a module.  If so, the module
          will be called i2c-ibm_iic.
 
+config I2C_IMX
+       tristate "IMX I2C interface"
+       depends on ARCH_MXC
+       help
+         Say Y here if you want to use the IIC bus controller on
+         the Freescale i.MX/MXC processors.
+
+         This driver can also be built as a module.  If so, the module
+         will be called i2c-imx.
+
 config I2C_IOP3XX
        tristate "Intel IOPx3xx and IXP4xx on-chip I2C interface"
        depends on ARCH_IOP32X || ARCH_IOP33X || ARCH_IXP4XX || ARCH_IOP13XX
index 0c2c4b26cdf1ff4d5bac686a40a4a306bf0e730f..657ab2428011e3a9b4ea31198886005e6e30f684 100644 (file)
@@ -33,6 +33,7 @@ obj-$(CONFIG_I2C_DAVINCI)     += i2c-davinci.o
 obj-$(CONFIG_I2C_GPIO)         += i2c-gpio.o
 obj-$(CONFIG_I2C_HIGHLANDER)   += i2c-highlander.o
 obj-$(CONFIG_I2C_IBM_IIC)      += i2c-ibm_iic.o
+obj-$(CONFIG_I2C_IMX)          += i2c-imx.o
 obj-$(CONFIG_I2C_IOP3XX)       += i2c-iop3xx.o
 obj-$(CONFIG_I2C_IXP2000)      += i2c-ixp2000.o
 obj-$(CONFIG_I2C_MPC)          += i2c-mpc.o
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
new file mode 100644 (file)
index 0000000..22cf200
--- /dev/null
@@ -0,0 +1,617 @@
+/*
+ *     Copyright (C) 2002 Motorola GSG-China
+ *
+ *     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., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ *     USA.
+ *
+ * Author:
+ *     Darius Augulis, Teltonika Inc.
+ *
+ * Desc.:
+ *     Implementation of I2C Adapter/Algorithm Driver
+ *     for I2C Bus integrated in Freescale i.MX/MXC processors
+ *
+ *     Derived from Motorola GSG China I2C example driver
+ *
+ *     Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de
+ *     Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de
+ *     Copyright (C) 2007 RightHand Technologies, Inc.
+ *     Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt>
+ *
+ */
+
+/** Includes *******************************************************************
+*******************************************************************************/
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/sched.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+
+#include <mach/irqs.h>
+#include <mach/hardware.h>
+#include <mach/i2c.h>
+
+/** Defines ********************************************************************
+*******************************************************************************/
+
+/* This will be the driver name the kernel reports */
+#define DRIVER_NAME "imx-i2c"
+
+/* Default value */
+#define IMX_I2C_BIT_RATE       100000  /* 100kHz */
+
+/* IMX I2C registers */
+#define IMX_I2C_IADR   0x00    /* i2c slave address */
+#define IMX_I2C_IFDR   0x04    /* i2c frequency divider */
+#define IMX_I2C_I2CR   0x08    /* i2c control */
+#define IMX_I2C_I2SR   0x0C    /* i2c status */
+#define IMX_I2C_I2DR   0x10    /* i2c transfer data */
+
+/* Bits of IMX I2C registers */
+#define I2SR_RXAK      0x01
+#define I2SR_IIF       0x02
+#define I2SR_SRW       0x04
+#define I2SR_IAL       0x10
+#define I2SR_IBB       0x20
+#define I2SR_IAAS      0x40
+#define I2SR_ICF       0x80
+#define I2CR_RSTA      0x04
+#define I2CR_TXAK      0x08
+#define I2CR_MTX       0x10
+#define I2CR_MSTA      0x20
+#define I2CR_IIEN      0x40
+#define I2CR_IEN       0x80
+
+/** Variables ******************************************************************
+*******************************************************************************/
+
+static unsigned int disable_delay;     /* Dummy delay */
+
+/*
+ * sorted list of clock divider, register value pairs
+ * taken from table 26-5, p.26-9, Freescale i.MX
+ * Integrated Portable System Processor Reference Manual
+ * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
+ *
+ * Duplicated divider values removed from list
+ */
+
+static u16 __initdata i2c_clk_div[50][2] = {
+       { 22,   0x20 }, { 24,   0x21 }, { 26,   0x22 }, { 28,   0x23 },
+       { 30,   0x00 }, { 32,   0x24 }, { 36,   0x25 }, { 40,   0x26 },
+       { 42,   0x03 }, { 44,   0x27 }, { 48,   0x28 }, { 52,   0x05 },
+       { 56,   0x29 }, { 60,   0x06 }, { 64,   0x2A }, { 72,   0x2B },
+       { 80,   0x2C }, { 88,   0x09 }, { 96,   0x2D }, { 104,  0x0A },
+       { 112,  0x2E }, { 128,  0x2F }, { 144,  0x0C }, { 160,  0x30 },
+       { 192,  0x31 }, { 224,  0x32 }, { 240,  0x0F }, { 256,  0x33 },
+       { 288,  0x10 }, { 320,  0x34 }, { 384,  0x35 }, { 448,  0x36 },
+       { 480,  0x13 }, { 512,  0x37 }, { 576,  0x14 }, { 640,  0x38 },
+       { 768,  0x39 }, { 896,  0x3A }, { 960,  0x17 }, { 1024, 0x3B },
+       { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
+       { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
+       { 3072, 0x1E }, { 3840, 0x1F }
+};
+
+struct imx_i2c_struct {
+       struct i2c_adapter      adapter;
+       struct resource         *res;
+       struct clk              *clk;
+       void __iomem            *base;
+       int                     irq;
+       wait_queue_head_t       queue;
+       unsigned long           i2csr;
+};
+
+/** Functions for IMX I2C adapter driver ***************************************
+*******************************************************************************/
+
+static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx)
+{
+       unsigned long orig_jiffies = jiffies;
+
+       dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
+
+       /* wait for bus not busy */
+       while (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_IBB) {
+               if (signal_pending(current)) {
+                       dev_dbg(&i2c_imx->adapter.dev,
+                               "<%s> I2C Interrupted\n", __func__);
+                       return -EINTR;
+               }
+               if (time_after(jiffies, orig_jiffies + HZ / 1000)) {
+                       dev_dbg(&i2c_imx->adapter.dev,
+                               "<%s> I2C bus is busy\n", __func__);
+                       return -EIO;
+               }
+               schedule();
+       }
+
+       return 0;
+}
+
+static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
+{
+       int result;
+
+       result = wait_event_interruptible_timeout(i2c_imx->queue,
+               i2c_imx->i2csr & I2SR_IIF, HZ / 10);
+
+       if (unlikely(result < 0)) {
+               dev_dbg(&i2c_imx->adapter.dev, "<%s> result < 0\n", __func__);
+               return result;
+       } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
+               dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
+               return -ETIMEDOUT;
+       }
+       dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
+       i2c_imx->i2csr = 0;
+       return 0;
+}
+
+static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
+{
+       if (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK) {
+               dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
+               return -EIO;  /* No ACK */
+       }
+
+       dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
+       return 0;
+}
+
+static void i2c_imx_start(struct imx_i2c_struct *i2c_imx)
+{
+       unsigned int temp = 0;
+
+       dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
+
+       /* Enable I2C controller */
+       writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
+       /* Start I2C transaction */
+       temp = readb(i2c_imx->base + IMX_I2C_I2CR);
+       temp |= I2CR_MSTA;
+       writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+       temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
+       writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+}
+
+static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
+{
+       unsigned int temp = 0;
+
+       /* Stop I2C transaction */
+       dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
+       temp = readb(i2c_imx->base + IMX_I2C_I2CR);
+       temp &= ~I2CR_MSTA;
+       writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+       /* setup chip registers to defaults */
+       writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
+       writeb(0, i2c_imx->base + IMX_I2C_I2SR);
+       /*
+        * This delay caused by an i.MXL hardware bug.
+        * If no (or too short) delay, no "STOP" bit will be generated.
+        */
+       udelay(disable_delay);
+       /* Disable I2C controller */
+       writeb(0, i2c_imx->base + IMX_I2C_I2CR);
+}
+
+static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
+                                                       unsigned int rate)
+{
+       unsigned int i2c_clk_rate;
+       unsigned int div;
+       int i;
+
+       /* Divider value calculation */
+       i2c_clk_rate = clk_get_rate(i2c_imx->clk);
+       div = (i2c_clk_rate + rate - 1) / rate;
+       if (div < i2c_clk_div[0][0])
+               i = 0;
+       else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
+               i = ARRAY_SIZE(i2c_clk_div) - 1;
+       else
+               for (i = 0; i2c_clk_div[i][0] < div; i++);
+
+       /* Write divider value to register */
+       writeb(i2c_clk_div[i][1], i2c_imx->base + IMX_I2C_IFDR);
+
+       /*
+        * There dummy delay is calculated.
+        * It should be about one I2C clock period long.
+        * This delay is used in I2C bus disable function
+        * to fix chip hardware bug.
+        */
+       disable_delay = (500000U * i2c_clk_div[i][0]
+               + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
+
+       /* dev_dbg() can't be used, because adapter is not yet registered */
+#ifdef CONFIG_I2C_DEBUG_BUS
+       printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
+               __func__, i2c_clk_rate, div);
+       printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
+               __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
+#endif
+}
+
+static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
+{
+       struct imx_i2c_struct *i2c_imx = dev_id;
+       unsigned int temp;
+
+       temp = readb(i2c_imx->base + IMX_I2C_I2SR);
+       if (temp & I2SR_IIF) {
+               /* save status register */
+               i2c_imx->i2csr = temp;
+               temp &= ~I2SR_IIF;
+               writeb(temp, i2c_imx->base + IMX_I2C_I2SR);
+               wake_up_interruptible(&i2c_imx->queue);
+               return IRQ_HANDLED;
+       }
+
+       return IRQ_NONE;
+}
+
+static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
+{
+       int i, result;
+
+       dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
+               __func__, msgs->addr << 1);
+
+       /* write slave address */
+       writeb(msgs->addr << 1, i2c_imx->base + IMX_I2C_I2DR);
+       result = i2c_imx_trx_complete(i2c_imx);
+       if (result)
+               return result;
+       result = i2c_imx_acked(i2c_imx);
+       if (result)
+               return result;
+       dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
+
+       /* write data */
+       for (i = 0; i < msgs->len; i++) {
+               dev_dbg(&i2c_imx->adapter.dev,
+                       "<%s> write byte: B%d=0x%X\n",
+                       __func__, i, msgs->buf[i]);
+               writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
+               result = i2c_imx_trx_complete(i2c_imx);
+               if (result)
+                       return result;
+               result = i2c_imx_acked(i2c_imx);
+               if (result)
+                       return result;
+       }
+       return 0;
+}
+
+static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
+{
+       int i, result;
+       unsigned int temp;
+
+       dev_dbg(&i2c_imx->adapter.dev,
+               "<%s> write slave address: addr=0x%x\n",
+               __func__, (msgs->addr << 1) | 0x01);
+
+       /* write slave address */
+       writeb((msgs->addr << 1) | 0x01, i2c_imx->base + IMX_I2C_I2DR);
+       result = i2c_imx_trx_complete(i2c_imx);
+       if (result)
+               return result;
+       result = i2c_imx_acked(i2c_imx);
+       if (result)
+               return result;
+
+       dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
+
+       /* setup bus to read data */
+       temp = readb(i2c_imx->base + IMX_I2C_I2CR);
+       temp &= ~I2CR_MTX;
+       if (msgs->len - 1)
+               temp &= ~I2CR_TXAK;
+       writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+       readb(i2c_imx->base + IMX_I2C_I2DR); /* dummy read */
+
+       dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
+
+       /* read data */
+       for (i = 0; i < msgs->len; i++) {
+               result = i2c_imx_trx_complete(i2c_imx);
+               if (result)
+                       return result;
+               if (i == (msgs->len - 1)) {
+                       dev_dbg(&i2c_imx->adapter.dev,
+                               "<%s> clear MSTA\n", __func__);
+                       temp = readb(i2c_imx->base + IMX_I2C_I2CR);
+                       temp &= ~I2CR_MSTA;
+                       writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+               } else if (i == (msgs->len - 2)) {
+                       dev_dbg(&i2c_imx->adapter.dev,
+                               "<%s> set TXAK\n", __func__);
+                       temp = readb(i2c_imx->base + IMX_I2C_I2CR);
+                       temp |= I2CR_TXAK;
+                       writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+               }
+               msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
+               dev_dbg(&i2c_imx->adapter.dev,
+                       "<%s> read byte: B%d=0x%X\n",
+                       __func__, i, msgs->buf[i]);
+       }
+       return 0;
+}
+
+static int i2c_imx_xfer(struct i2c_adapter *adapter,
+                                               struct i2c_msg *msgs, int num)
+{
+       unsigned int i, temp;
+       int result;
+       struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
+
+       dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
+
+       /* Check if i2c bus is not busy */
+       result = i2c_imx_bus_busy(i2c_imx);
+       if (result)
+               goto fail0;
+
+       /* Start I2C transfer */
+       i2c_imx_start(i2c_imx);
+
+       /* read/write data */
+       for (i = 0; i < num; i++) {
+               if (i) {
+                       dev_dbg(&i2c_imx->adapter.dev,
+                               "<%s> repeated start\n", __func__);
+                       temp = readb(i2c_imx->base + IMX_I2C_I2CR);
+                       temp |= I2CR_RSTA;
+                       writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+               }
+               dev_dbg(&i2c_imx->adapter.dev,
+                       "<%s> transfer message: %d\n", __func__, i);
+               /* write/read data */
+#ifdef CONFIG_I2C_DEBUG_BUS
+               temp = readb(i2c_imx->base + IMX_I2C_I2CR);
+               dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
+                       "MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
+                       (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
+                       (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
+                       (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
+               temp = readb(i2c_imx->base + IMX_I2C_I2SR);
+               dev_dbg(&i2c_imx->adapter.dev,
+                       "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
+                       "IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
+                       (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
+                       (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
+                       (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
+                       (temp & I2SR_RXAK ? 1 : 0));
+#endif
+               if (msgs[i].flags & I2C_M_RD)
+                       result = i2c_imx_read(i2c_imx, &msgs[i]);
+               else
+                       result = i2c_imx_write(i2c_imx, &msgs[i]);
+       }
+
+fail0:
+       /* Stop I2C transfer */
+       i2c_imx_stop(i2c_imx);
+
+       dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
+               (result < 0) ? "error" : "success msg",
+                       (result < 0) ? result : num);
+       return (result < 0) ? result : num;
+}
+
+static u32 i2c_imx_func(struct i2c_adapter *adapter)
+{
+       return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm i2c_imx_algo = {
+       .master_xfer    = i2c_imx_xfer,
+       .functionality  = i2c_imx_func,
+};
+
+static int __init i2c_imx_probe(struct platform_device *pdev)
+{
+       struct imx_i2c_struct *i2c_imx;
+       struct resource *res;
+       struct imxi2c_platform_data *pdata;
+       void __iomem *base;
+       resource_size_t res_size;
+       int irq;
+       int ret;
+
+       dev_dbg(&pdev->dev, "<%s>\n", __func__);
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res) {
+               dev_err(&pdev->dev, "can't get device resources\n");
+               return -ENOENT;
+       }
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               dev_err(&pdev->dev, "can't get irq number\n");
+               return -ENOENT;
+       }
+
+       pdata = pdev->dev.platform_data;
+
+       if (pdata && pdata->init) {
+               ret = pdata->init(&pdev->dev);
+               if (ret)
+                       return ret;
+       }
+
+       res_size = resource_size(res);
+       base = ioremap(res->start, res_size);
+       if (!base) {
+               dev_err(&pdev->dev, "ioremap failed\n");
+               ret = -EIO;
+               goto fail0;
+       }
+
+       i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
+       if (!i2c_imx) {
+               dev_err(&pdev->dev, "can't allocate interface\n");
+               ret = -ENOMEM;
+               goto fail1;
+       }
+
+       /* Setup i2c_imx driver structure */
+       strcpy(i2c_imx->adapter.name, pdev->name);
+       i2c_imx->adapter.owner          = THIS_MODULE;
+       i2c_imx->adapter.algo           = &i2c_imx_algo;
+       i2c_imx->adapter.dev.parent     = &pdev->dev;
+       i2c_imx->adapter.nr             = pdev->id;
+       i2c_imx->irq                    = irq;
+       i2c_imx->base                   = base;
+       i2c_imx->res                    = res;
+
+       /* Get I2C clock */
+       i2c_imx->clk = clk_get(&pdev->dev, "i2c_clk");
+       if (IS_ERR(i2c_imx->clk)) {
+               ret = PTR_ERR(i2c_imx->clk);
+               dev_err(&pdev->dev, "can't get I2C clock\n");
+               goto fail2;
+       }
+       clk_enable(i2c_imx->clk);
+
+       /* Request IRQ */
+       ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
+       if (ret) {
+               dev_err(&pdev->dev, "can't claim irq %d\n", i2c_imx->irq);
+               goto fail3;
+       }
+
+       /* Init queue */
+       init_waitqueue_head(&i2c_imx->queue);
+
+       /* Set up adapter data */
+       i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
+
+       /* Set up clock divider */
+       if (pdata && pdata->bitrate)
+               i2c_imx_set_clk(i2c_imx, pdata->bitrate);
+       else
+               i2c_imx_set_clk(i2c_imx, IMX_I2C_BIT_RATE);
+
+       /* Set up chip registers to defaults */
+       writeb(0, i2c_imx->base + IMX_I2C_I2CR);
+       writeb(0, i2c_imx->base + IMX_I2C_I2SR);
+
+       /* Add I2C adapter */
+       ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
+       if (ret < 0) {
+               dev_err(&pdev->dev, "registration failed\n");
+               goto fail4;
+       }
+
+       /* Set up platform driver data */
+       platform_set_drvdata(pdev, i2c_imx);
+
+       dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", i2c_imx->irq);
+       dev_dbg(&i2c_imx->adapter.dev, "device resources from 0x%x to 0x%x\n",
+               i2c_imx->res->start, i2c_imx->res->end);
+       dev_dbg(&i2c_imx->adapter.dev, "allocated %d bytes at 0x%x \n",
+               res_size, i2c_imx->res->start);
+       dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
+               i2c_imx->adapter.name);
+       dev_dbg(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
+
+       return 0;   /* Return OK */
+
+fail4:
+       free_irq(i2c_imx->irq, i2c_imx);
+fail3:
+       clk_disable(i2c_imx->clk);
+       clk_put(i2c_imx->clk);
+fail2:
+       kfree(i2c_imx);
+fail1:
+       iounmap(base);
+fail0:
+       if (pdata && pdata->exit)
+               pdata->exit(&pdev->dev);
+       return ret; /* Return error number */
+}
+
+static int __exit i2c_imx_remove(struct platform_device *pdev)
+{
+       struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
+       struct imxi2c_platform_data *pdata = pdev->dev.platform_data;
+
+       /* remove adapter */
+       dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
+       i2c_del_adapter(&i2c_imx->adapter);
+       platform_set_drvdata(pdev, NULL);
+
+       /* free interrupt */
+       free_irq(i2c_imx->irq, i2c_imx);
+
+       /* setup chip registers to defaults */
+       writeb(0, i2c_imx->base + IMX_I2C_IADR);
+       writeb(0, i2c_imx->base + IMX_I2C_IFDR);
+       writeb(0, i2c_imx->base + IMX_I2C_I2CR);
+       writeb(0, i2c_imx->base + IMX_I2C_I2SR);
+
+       /* Shut down hardware */
+       if (pdata && pdata->exit)
+               pdata->exit(&pdev->dev);
+
+       /* Disable I2C clock */
+       clk_disable(i2c_imx->clk);
+       clk_put(i2c_imx->clk);
+
+       iounmap(i2c_imx->base);
+       kfree(i2c_imx);
+       return 0;
+}
+
+static struct platform_driver i2c_imx_driver = {
+       .probe          = i2c_imx_probe,
+       .remove         = __exit_p(i2c_imx_remove),
+       .driver = {
+               .name   = DRIVER_NAME,
+               .owner  = THIS_MODULE,
+       }
+};
+
+static int __init i2c_adap_imx_init(void)
+{
+       return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
+}
+
+static void __exit i2c_adap_imx_exit(void)
+{
+       platform_driver_unregister(&i2c_imx_driver);
+}
+
+module_init(i2c_adap_imx_init);
+module_exit(i2c_adap_imx_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Darius Augulis");
+MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
+MODULE_ALIAS("platform:" DRIVER_NAME);