From: Darius Augulis <augulis.darius@xxxxxxxxx>
Implementation of I2C Adapter/Algorithm Driver for I2C Bus integrated
in Freescale's i.MX/MXC processors. Tested only on MX1, but should work on MX2
and MX3 too, because all three processors have the same I2C controller.
Signed-off-by: Darius Augulis <augulis.darius@xxxxxxxxx>
Index: linux-2.6.28-rc7/drivers/i2c/busses/i2c-imx.c
===================================================================
--- /dev/null
+++ linux-2.6.28-rc7/drivers/i2c/busses/i2c-imx.c
@@ -0,0 +1,624 @@
+/*
+ * 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 or 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 -ENODEV;
+ }
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "can't get irq number\n");
+ return -ENODEV;
+ }
+
+ pdata = pdev->dev.platform_data;
+ if (!pdata) {
+ dev_err(&pdev->dev, "I2C driver needs platform data\n");
+ return -ENODEV;
+ }
+
+ if (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->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->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->exit)
+ pdata->exit(&pdev->dev);
+
+ /* Disable I2C clock */
+ clk_disable(i2c_imx->clk);
+ clk_put(i2c_imx->clk);
+
+ /* Release memory */
+ release_mem_region(i2c_imx->res->start,
+ i2c_imx->res->end - i2c_imx->res->start + 1);
+ 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);
Index: linux-2.6.28-rc7/drivers/i2c/busses/Kconfig
===================================================================
--- linux-2.6.28-rc7.orig/drivers/i2c/busses/Kconfig
+++ linux-2.6.28-rc7/drivers/i2c/busses/Kconfig
@@ -355,6 +355,16 @@ 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: linux-2.6.28-rc7/drivers/i2c/busses/Makefile
===================================================================
--- linux-2.6.28-rc7.orig/drivers/i2c/busses/Makefile
+++ linux-2.6.28-rc7/drivers/i2c/busses/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci
obj-$(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
Index: linux-2.6.28-rc7/arch/arm/plat-mxc/include/mach/i2c.h
===================================================================
--- /dev/null
+++ linux-2.6.28-rc7/arch/arm/plat-mxc/include/mach/i2c.h
@@ -0,0 +1,23 @@
+/*
+ * i2c.h - i.MX I2C driver header file
+ *
+ * Copyright (c) 2008, Darius Augulis <augulis.darius@xxxxxxxxx>
+ *
+ * This file is released under the GPLv2
+ */
+
+#ifndef __ASM_ARCH_I2C_H_
+#define __ASM_ARCH_I2C_H_
+
+/*
+ * @init: Initialise gpio's and other board specific things
+ * @exit: Free everything initialised by @init
+ *
+ */
+struct imxi2c_platform_data {
+ int (*init)(struct device *dev);
+ void (*exit)(struct device *dev);
+ int bitrate;
+};
+
+#endif /* __ASM_ARCH_I2C_H_ */
