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I2C driver for IMX

PATCH Superseded Darius 6 participants 8 messages Mar 13, 2008 – Mar 14, 2008 2 messages not in the archive

Subsystems (3)
Arm i.MX and Layerscape I2C subsystem host drivers Freescale i.MX I2C driver

v1 of 12 Superseded Latest is v12 →

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Darius

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PATCH 1/1 I2C driver for IMX

Almost written from scratch - only small piece of code leaved from old driver, witch never was originally in vanilla kernel. SMB is NOT supported currently.
Tested on the MXLADS v2.0 board with i2c client driver (driver for NT7651 LCD controller). All works fine, stable.

drivers/i2c/busses/i2c-imx.c +713 -0
diff -uprN -X linux-2.6.24.3-vanilla/Documentation/dontdiff linux-2.6.24.3-vanilla/drivers/i2c/busses/i2c-imx.c linux-2.6.24.3/drivers/i2c/busses/i2c-imx.c
@@ -0,0 +1,713 @@
+/*
+ *	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.
+ *
+ * File Name: imx-i2c.c
+ *
+ * Author:  Torsten Koschorrek, synertronixx GmbH
+ *
+ * Desc.:   Implementation of I2C Adapter/Algorithm Driver
+ *          Driver for I2C Bus integrated in i.MXL, i.MX1
+ *
+ *          compiler options: - I2C_IMX_DEBUG:
+ *                              Enables debug output. If not set, no debug
+ *                              is compiled into the driver.
+ *
+ *          module parameter: - clkdiv:
+ *                              Sets the desired clock rate
+ *                              The default value is 100000
+ *
+ *          Derived from Motorola GSG China I2C example driver
+ *
+ *          Copyright (C) 2002 Motorola GSG-China
+ *          Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de
+ *          Portions:
+ *          Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de
+ *          Copyright (C) 2007 RightHand Technologies, Inc. <adyer at righthandtech.com>
+ *          Copyright (C) 2008 Darius Augulis <augulis.darius at gmail.com>
+ *
+ * History: 2002/2/07 use msgs[]
+ *                    Motorola GSG-China
+ *          2004/3/03 port to linux kernel v2.6.x for i.MX
+ *                    adding ioctl (change bus freq)
+ *                    adding cpu- and bus-usage optimization (..slp)
+ *                    T. Koschorrek <koschorrek at synertronixx.de
+ *          2005/2/28 changes in timings
+ *                    M. Blaschke <blaschke at synertronixx.de
+ *          2005/6/01 added module parameters, cleaning up, cpu- and bus-usage
+ *                    modularized (..slave)
+ *                    T. Koschorrek <koschorrek at synertronixx.de
+ *
+ *          2007/07/13 rewrote sections based on comments from Russell King
+ *                     http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2006-April/034215..html
+ *                     Andrew Dyer <adyer at righthandtech.com>
+ *
+ *          2007/09/02 changed to a 'platform' driver
+ *                     Andrew Dyer <adyer at righthandtech.com>
+ *
+ *          2008/03/13 Major changes in driver structure. Works with 2.6.24 kernel.
+ *                     Darius Augulis <augulis.darius at gmail.com>
+ */
+
+/** Includes *******************************************************************
+*******************************************************************************/
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+
+#include <asm/arch/irqs.h>
+#include <asm/arch/hardware.h>
+#include <asm/io.h>
+
+
+/** Defines ********************************************************************
+*******************************************************************************/
+
+/* This will be the driver name the kernel reports */
+#define DRIVER_NAME "imx-i2c"
+
+/* Default values of module parameters */
+#define IMX_I2C_SLAVE_ADDR  0xAC
+#define IMX_I2C_BIT_RATE    100000
+
+/* These defines are missed in imx-regs.h */
+#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 in IMX_I2C_I2SR register */
+#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
+
+/* bits in IMX_I2C_I2CR register */
+#define I2CR_RSTA	0x04
+#define I2CR_TXAK	0x08
+#define I2CR_MTX	0x10
+#define I2CR_MSTA	0x20
+#define I2CR_IIEN	0x40
+#define I2CR_IEN	0x80
+
+/* Timeouts */
+#define I2C_IMX_TIME_BUSY   2000
+#define I2C_IMX_TIME_ACK    2000
+
+/* Error numbers */
+#define I2C_IMX_ERR_BUSY        1
+#define I2C_IMX_ERR_TX_TIMEOUT  2
+#define I2C_IMX_ERR_RX_TIMEOUT  3
+#define I2C_IMX_ERR_RX_NO_ACK   4
+
+/** Function prototypes ********************************************************
+*******************************************************************************/
+
+static int          i2c_imx_xfer    (struct i2c_adapter *adapter, struct i2c_msg *msgs, int num);
+static u32          i2c_imx_func    (struct i2c_adapter *adapter);
+static int __init   i2c_imx_probe   (struct platform_device *pdev);
+static int 	    i2c_imx_remove  (struct platform_device *pdev);
+
+/** Variables ******************************************************************
+*******************************************************************************/
+
+static unsigned int clkfreq = IMX_I2C_BIT_RATE;
+static unsigned int imxslave = IMX_I2C_SLAVE_ADDR;;
+
+struct i2c_imx_clk_div_pair {
+	unsigned int divider;
+	unsigned int setting;
+};
+
+static struct i2c_imx_clk_div_pair i2c_imx_clk_div_tbl[64] = { /* FIXME */
+	{22,   0x20}, {24,   0x21}, {26,   0x22}, {28,   0x23},
+	{30,   0x00}, {32,   0x01}, {32,   0x24}, {36,   0x02},
+	{36,   0x25}, {40,   0x26}, {42,   0x03}, {44,   0x27},
+	{48,   0x04}, {48,   0x28}, {52,   0x05}, {56,   0x29},
+	{60,   0x06}, {64,   0x2A}, {72,   0x07}, {72,   0x2B},
+	{80,   0x08}, {80,   0x2C}, {88,   0x09}, {96,   0x2D},
+	{104,  0x0A}, {112,  0x2E}, {128,  0x0B}, {128,  0x2F},
+	{144,  0x0C}, {160,  0x0D}, {160,  0x30}, {192,  0x0E},
+	{192,  0x31}, {224,  0x32}, {240,  0x0F}, {256,  0x33},
+	{288,  0x10}, {320,  0x11}, {320,  0x34}, {384,  0x12},
+	{384,  0x35}, {448,  0x36}, {480,  0x13}, {512,  0x37},
+	{576,  0x14}, {640,  0x15}, {640,  0x38}, {768,  0x16},
+	{768,  0x39}, {896,  0x3A}, {960,  0x17}, {1024, 0x3B},
+	{1152, 0x18}, {1280, 0x19}, {1280, 0x3C}, {1536, 0x1A},
+	{1536, 0x3D}, {1792, 0x3E}, {1920, 0x1B}, {2048, 0x3F},
+	{2304, 0x1C}, {2560, 0x1D}, {3072, 0x1E}, {3840, 0x1F}
+};
+
+static struct platform_driver i2c_imx_driver = {
+	.probe		= i2c_imx_probe,
+	.remove		= i2c_imx_remove,
+	.driver		= {
+		.name	= DRIVER_NAME,
+        .owner	= THIS_MODULE,
+	}
+};
+
+static struct i2c_algorithm i2c_imx_algo = {
+	.master_xfer   =	i2c_imx_xfer,
+	.functionality =	i2c_imx_func,
+};
+
+struct imx_i2c_struct {
+    struct i2c_adapter  adapter;
+	struct resource		*res;
+	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 int i = 0;
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_bus_busy>\n");
+    #endif
+	/* wait for bus not busy */
+	for (i=0; i<I2C_IMX_TIME_BUSY; i++) {
+		if (!(readb(i2c_imx->base + IMX_I2C_I2SR) & (I2SR_IBB | I2SR_IAL)))
+			return 0;
+		udelay(1);
+	}
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_bus_busy> I2C bus is busy!\n");
+    #endif
+	return -I2C_IMX_ERR_BUSY;
+}
+
+static int i2c_imx_trx_complete (struct imx_i2c_struct *i2c_imx) {
+
+    int result;
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_trx_complete>\n");
+    #endif
+
+    result =    wait_event_interruptible_timeout(i2c_imx->queue,
+                (i2c_imx->i2csr & I2SR_IIF), 5 * HZ);
+
+    if (unlikely(result < 0)) {
+        #ifdef CONFIG_I2C_DEBUG_BUS
+            printk("I2C: <i2c_imx_trx_complete> result < 0!\n");
+        #endif
+        return result;
+    }
+    else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
+        #ifdef CONFIG_I2C_DEBUG_BUS
+            printk("I2C: <i2c_imx_trx_complete> Timeout!\n");
+        #endif
+        return -I2C_IMX_ERR_TX_TIMEOUT;
+    }
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_trx_complete> TRX complete!\n");
+    #endif
+    i2c_imx->i2csr = 0;
+	return 0;
+}
+
+static int i2c_imx_acked        (struct imx_i2c_struct *i2c_imx) {
+
+    unsigned int i = 0;
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_acked>\n");
+	#endif
+
+    for (i=0; i<I2C_IMX_TIME_ACK; i++) {
+		if (!(readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK)) {
+            #ifdef CONFIG_I2C_DEBUG_BUS
+                printk("I2C: <i2c_imx_acked> ACK received\n");
+            #endif
+			return 0;
+		}
+		udelay(1);
+	}
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_acked> No ACK!\n");
+    #endif
+    return -I2C_IMX_ERR_RX_NO_ACK;   // No ACK
+
+}
+
+static void i2c_imx_enable      (struct imx_i2c_struct *i2c_imx) {
+
+    unsigned int temp = 0;
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_enable>\n");
+    #endif
+	temp = I2CR_IEN;
+    writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+}
+
+static void i2c_imx_disable     (struct imx_i2c_struct *i2c_imx) {
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_disable>\n");
+    #endif
+
+	/* setup chip registers to defaults */
+    writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
+    writeb(0, i2c_imx->base + IMX_I2C_I2SR);
+
+}
+
+static void i2c_imx_start       (struct imx_i2c_struct *i2c_imx) {
+
+    unsigned int temp = 0;
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_start>\n");
+    #endif
+	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);
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        temp = readb (i2c_imx->base + IMX_I2C_I2CR);
+        printk("I2C: <i2c_imx_start> CONTROL: IEN=%d, IIEN=%d, MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n",
+            (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);
+        printk("I2C: <i2c_imx_start> STATUS: ICF=%d, IAAS=%d, IBB=%d, IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n",
+            (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
+}
+
+static void i2c_imx_stop        (struct imx_i2c_struct *i2c_imx) {
+
+    unsigned int temp = 0;
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_stop>\n");
+    #endif
+	temp = readb ( i2c_imx->base + IMX_I2C_I2CR);
+    temp &= ~I2CR_MSTA;
+    writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        temp = readb (i2c_imx->base + IMX_I2C_I2CR);
+        printk("I2C: <i2c_imx_stop> CONTROL: IEN=%d, IIEN=%d, MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n",
+            (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);
+        printk("I2C: <i2c_imx_stop> STATUS: ICF=%d, IAAS=%d, IBB=%d, IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n",
+            (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
+}
+
+static int i2c_imx_set_clk      (struct imx_i2c_struct *i2c_imx, unsigned int rate) {
+	unsigned int hclk, sysclk;
+	unsigned int desired_div;
+	int i;
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_set_clk>\n");
+    #endif
+
+	sysclk = imx_get_system_clk ();
+	hclk = imx_get_hclk();
+	desired_div = (hclk << 1) / rate;
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_set_clk> SYSCLK=%d, HCLK=%d, DIV=%d\n", sysclk, hclk, desired_div);
+    #endif
+	if (desired_div & 0x01)
+		desired_div++;
+	desired_div >>= 1;
+	if (desired_div < 22)
+		desired_div = 22;
+	if (desired_div > 3840)
+		return -EINVAL;
+	for (i=0; i<64; i++) {
+		if (i2c_imx_clk_div_tbl[i].divider >= desired_div)
+			break;
+	}
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_set_clk> ICC_FDR[IC]=0x%x, DIV=%d\n", i2c_imx_clk_div_tbl[i].setting, i2c_imx_clk_div_tbl[i].divider);
+    #endif
+	writeb(i2c_imx_clk_div_tbl[i].setting, i2c_imx->base + IMX_I2C_IFDR);
+	return (hclk / i2c_imx_clk_div_tbl[i].divider);
+}
+
+static irqreturn_t i2c_imx_isr  (int irq, void *dev_id) {
+
+	struct imx_i2c_struct *i2c_imx = dev_id;
+	unsigned int temp;
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_isr>\n");
+        temp = readb (i2c_imx->base + IMX_I2C_I2CR);
+        printk("I2C: <i2c_imx_isr> CONTROL: IEN=%d, IIEN=%d, MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n",
+            (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);
+        printk("I2C: <i2c_imx_isr> STATUS: ICF=%d, IAAS=%d, IBB=%d, IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n",
+            (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
+
+    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;
+}
+
+static int i2c_imx_write        (struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) {
+
+	int i;
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_write>\n");
+        printk("I2C: <i2c_imx_write> write slave address: addr=0x%x\n", (msgs->addr<<1));
+	#endif
+	/* write slave address */
+	writeb((msgs->addr<<1), i2c_imx->base + IMX_I2C_I2DR);
+	if (i2c_imx_trx_complete(i2c_imx))
+		return -I2C_IMX_ERR_TX_TIMEOUT;
+    if (i2c_imx_acked(i2c_imx))
+        return -I2C_IMX_ERR_RX_NO_ACK;
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_write> write data\n");
+	#endif
+	/* write data */
+	for (i = 0; i<msgs->len; i++) {
+        #ifdef CONFIG_I2C_DEBUG_BUS
+            printk("I2C: <i2c_imx_write> write byte: %d, b=0x%x\n", i, msgs->buf[i]);
+        #endif
+		writeb(msgs->buf[i], i2c_imx->base + IMX_I2C_I2DR);
+		if (i2c_imx_trx_complete(i2c_imx))
+			return -I2C_IMX_ERR_TX_TIMEOUT;
+        if (i2c_imx_acked(i2c_imx))
+            return -I2C_IMX_ERR_RX_NO_ACK;
+	}
+	return 0;
+}
+
+static int i2c_imx_read         (struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs) {
+
+	int i;
+	unsigned int temp;
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_read>\n");
+        printk("I2C: <i2c_imx_read> write slave address: addr=0x%x\n", (msgs->addr<<1));
+	#endif
+	/* write slave address */
+	writeb((msgs->addr<<1)|0x01, i2c_imx->base + IMX_I2C_I2DR);
+	if (i2c_imx_trx_complete(i2c_imx))
+		return -I2C_IMX_ERR_TX_TIMEOUT;
+    if (i2c_imx_acked(i2c_imx))
+        return -I2C_IMX_ERR_RX_NO_ACK;
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_read> setup bus\n");
+	#endif
+	/* 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);
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_read> dummy read\n");
+	#endif
+	readb(i2c_imx->base + IMX_I2C_I2DR); // dummy read
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_read> read data\n");
+	#endif
+	/* read data */
+	for (i=0; i < msgs->len; i++) {
+
+        if (i2c_imx_trx_complete(i2c_imx))
+			return -I2C_IMX_ERR_RX_TIMEOUT;
+
+        if (i==(msgs->len-1)) {
+            #ifdef CONFIG_I2C_DEBUG_BUS
+                printk("I2C: <i2c_imx_read> clear MSTA\n");
+            #endif
+            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)) {
+            #ifdef CONFIG_I2C_DEBUG_BUS
+                printk("I2C: <i2c_imx_read> set TXAK\n");
+            #endif
+            temp = readb(i2c_imx->base + IMX_I2C_I2CR);
+            temp |= I2CR_TXAK;
+            writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+        }
+		#ifdef CONFIG_I2C_DEBUG_BUS
+            printk("I2C: <i2c_imx_read> read byte B%d\n", i);
+        #endif
+		msgs->buf[i] = readb(i2c_imx->base + IMX_I2C_I2DR);
+	}
+	return 0;
+}
+
+static int i2c_imx_xfer         (struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) {
+
+	int i, temp;
+	int err = 0;
+	struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
+
+	#ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_xfer>\n");
+	#endif
+
+	// chech or i2c bus is not busy
+	err = i2c_imx_bus_busy(i2c_imx);
+	if (err)
+		goto fail0;
+
+    // Enable i2c
+    i2c_imx_enable(i2c_imx);
+
+    /* Start I2C transfer */
+    i2c_imx_start (i2c_imx);
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        temp = readb (i2c_imx->base + IMX_I2C_I2CR);
+        printk("I2C: <i2c_imx_xfer> CONTROL: IEN=%d, IIEN=%d, MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n",
+            (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);
+        printk("I2C: <i2c_imx_xfer> STATUS: ICF=%d, IAAS=%d, IBB=%d, IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n",
+            (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
+
+	// read/write data
+	for (i=0; i<num; i++) {
+
+		if (i) {
+            #ifdef CONFIG_I2C_DEBUG_BUS
+                printk("I2C: <i2c_imx_read> repeated start\n");
+            #endif
+            temp = readb(i2c_imx->base + IMX_I2C_I2CR);
+            temp |= I2CR_RSTA;
+            writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+		}
+		#ifdef CONFIG_I2C_DEBUG_BUS
+            printk("I2C: <i2c_imx_xfer> transfer message: %d\n", i);
+        #endif
+		/* write/read data */
+		if (!(msgs[i].flags & I2C_M_RD))
+			err = i2c_imx_write (i2c_imx, &msgs[i]);
+		else
+            err = i2c_imx_read  (i2c_imx, &msgs[i]);
+	}
+
+fail0:
+	/* Stop bus */
+	i2c_imx_stop (i2c_imx);
+	/* disable i2c bus */
+	i2c_imx_disable (i2c_imx);
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_xfer> exit with: %s: %d\n", (err < 0)?"error":"succes msg", (err < 0)?err:num);
+    #endif
+	return (err < 0) ? err : num;
+}
+
+static u32 i2c_imx_func         (struct i2c_adapter *adapter) {
+	return I2C_FUNC_I2C;
+}
+
+static int __init i2c_imx_probe (struct platform_device *pdev) {
+
+    struct imx_i2c_struct *i2c_imx;
+    struct resource *res;
+    void   __iomem	*base;
+    int irq;
+	int res_size;
+	int ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	irq = platform_get_irq(pdev, 0);
+	if (!res) {
+        printk("I2C: can't get device resources!\n");
+        return -ENODEV;
+	}
+	if (irq < 0) {
+        printk("I2C: can't get irq number!\n");
+        return -ENODEV;
+	}
+
+	res_size = (res->end) - (res->start) + 1;
+	if (!request_mem_region(res->start, res_size, res->name)) {
+		printk("I2C: can't allocate %d bytes at %d address!\n", res_size, res->start);
+		return -ENOMEM;
+	}
+
+	base = ioremap (res->start, res_size);
+	if (!base) {
+	    printk("I2C: ioremap failed!\n");
+		ret = -EIO;
+		goto fail0;
+	}
+
+	i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
+	if (!i2c_imx) {
+		printk("I2C: can't allocate inteface!\n");
+		ret = -ENOMEM;
+		goto fail1;
+	}
+
+    // Setup i2c_imx driver structure
+    i2c_imx->adapter.owner      = THIS_MODULE;
+	i2c_imx->adapter.algo       = &i2c_imx_algo;
+    i2c_imx->adapter.dev.parent = &pdev->dev;
+    strcpy (i2c_imx->adapter.name, pdev->name);
+    i2c_imx->irq    = irq;
+    i2c_imx->base   = base;
+    i2c_imx->res    = res;
+
+    init_waitqueue_head(&i2c_imx->queue);
+
+    /* Set up platform driver data */
+	platform_set_drvdata(pdev, i2c_imx);
+
+	ret = request_irq(i2c_imx->irq, i2c_imx_isr, IRQF_DISABLED, pdev->name, i2c_imx);
+	if (ret) {
+		printk("I2C: %s: cannot claim irq %d !\n", i2c_imx->adapter.dev.bus_id, i2c_imx->irq);
+		goto fail2;
+	}
+
+    /* Set up clock divider */
+    i2c_imx_set_clk(i2c_imx, clkfreq);
+
+    /* Set up IMX I2C slave address */
+    writeb(imxslave, i2c_imx->base + IMX_I2C_IADR);
+
+    /* Set up I/O pins for I2C*/
+	imx_gpio_mode(PA15_PF_I2C_SDA);
+	imx_gpio_mode(PA16_PF_I2C_SCL);
+
+    /* Set up chip registers to defaults */
+    writeb(0, i2c_imx->base + IMX_I2C_I2CR);
+    writeb(0, i2c_imx->base + IMX_I2C_I2SR);
+
+    /* Set up adapter data */
+    i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
+
+    /* Add I2C adapter */
+	ret = i2c_add_adapter(&i2c_imx->adapter);
+	if (ret < 0) {
+		printk("I2C: %s: registration failed\n", i2c_imx->adapter.dev.bus_id);
+		goto fail3;
+	}
+
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: %s: claimed irq %d\n", i2c_imx->adapter.dev.bus_id, i2c_imx->irq);
+        printk("I2C: %s: device resources from 0x%x to 0x%x\n", i2c_imx->adapter.dev.bus_id, i2c_imx->res->start, i2c_imx->res->end);
+		printk("I2C: %s: allocated %d bytes at 0x%x \n", i2c_imx->adapter.dev.bus_id, res_size, i2c_imx->res->start);
+		printk("I2C: %s: adapter name: \"%s\"\n", i2c_imx->adapter.dev.bus_id, i2c_imx->adapter.name);
+		printk("I2C: adapter \"%s\" associated with driver \"%s\"\n", i2c_imx->adapter.dev.bus_id, i2c_imx_driver.driver.name);
+    #endif
+
+	printk("I2C: %s: IMX I2C adapter registered\n", i2c_imx->adapter.dev.bus_id);
+	return 0;   // Return OK */
+
+fail3:
+	free_irq(i2c_imx->irq, i2c_imx);
+fail2:
+    platform_set_drvdata(pdev, NULL);
+	kfree(i2c_imx);
+fail1:
+	iounmap(i2c_imx->base);
+fail0:
+	release_mem_region(res->start, res_size);
+
+	return ret; // Return error number
+}
+
+static int i2c_imx_remove(struct platform_device *pdev) {
+
+	struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
+
+	/* remove adapter */
+	printk("I2C: 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);
+
+    /* 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 int __init i2c_adap_imx_init(void) {
+	return platform_driver_register(&i2c_imx_driver);
+}
+
+static void __exit i2c_adap_imx_exit(void) {
+	platform_driver_unregister(&i2c_imx_driver);
+	return;
+}
+
+module_init(i2c_adap_imx_init);
+module_exit(i2c_adap_imx_exit);
+
+MODULE_AUTHOR("Darius Augulis");
+MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
+MODULE_LICENSE("GPL");
+
+module_param(clkfreq, uint, S_IRUGO);
+MODULE_PARM_DESC(clkfreq, "desired IMX I2C Clock Rate in Hz");
+
+module_param(imxslave, uint, S_IRUGO);
+MODULE_PARM_DESC(imxslave, "desired IMX I2C slave address");
drivers/i2c/busses/Kconfig +10 -0
diff -uprN -X linux-2.6.24.3-vanilla/Documentation/dontdiff linux-2.6.24.3-vanilla/drivers/i2c/busses/Kconfig linux-2.6.24.3/drivers/i2c/busses/Kconfig
@@ -249,6 +249,16 @@ 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_IMX
+	help
+	  Say Y here if you want to use the IIC bus controller on
+	  the Freescale IMX 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
drivers/i2c/busses/Makefile +1 -0
diff -uprN -X linux-2.6.24.3-vanilla/Documentation/dontdiff linux-2.6.24.3-vanilla/drivers/i2c/busses/Makefile linux-2.6.24.3/drivers/i2c/busses/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_I2C_HYDRA)		+= i2c-hydra.o
 obj-$(CONFIG_I2C_I801)		+= i2c-i801.o
 obj-$(CONFIG_I2C_I810)		+= i2c-i810.o
 obj-$(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_IXP4XX)	+= i2c-ixp4xx.o

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#1 lore raw

On Thu, Mar 13, 2008 at 06:07:45PM +0200, Darius wrote:

Hello,

(I know I am myself quite new here. I don't want to boast, just trying to be a little bit helpful.)

I found some things concerning the formal side:

Quoted 1 line

+ * History: 2002/2/07 use msgs[]

I have been told here that histories are not wanted as they are achieved through git.

drivers/i2c/busses/i2c-imx.c line 172

Quoted 6 lines
drivers/i2c/busses/i2c-imx.c +6 -0
+static struct platform_driver i2c_imx_driver = {
+	.probe		= i2c_imx_probe,
+	.remove		= i2c_imx_remove,
+	.driver		= {
+		.name	= DRIVER_NAME,
+        .owner	= THIS_MODULE,

Indentation seems wrong here and in some other places...

drivers/i2c/busses/i2c-imx.c line 184

Quoted 4 lines
drivers/i2c/busses/i2c-imx.c +4 -0
+struct imx_i2c_struct {
+    struct i2c_adapter  adapter;
+	struct resource		*res;
+	void   __iomem		*base;

...like here and so on.

drivers/i2c/busses/i2c-imx.c line 199

Quoted 3 lines
drivers/i2c/busses/i2c-imx.c +3 -0
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_bus_busy>\n");
+    #endif

Maybe you can define a debug-printing-macro that only prints when DEBUG_BUS is set and is simply empty when it is unset? This should make the code more readable, I think (or use pr_debug).

drivers/i2c/busses/i2c-imx.c line 502

Quoted 1 line
drivers/i2c/busses/i2c-imx.c +1 -0
+	// chech or i2c bus is not busy

CodingStyle suggests not using //.

All the best,

Wolfram

Signature · 2 lines
  Dipl.-Ing. Wolfram Sang | http://www.pengutronix.de
 Pengutronix - Linux Solutions for Science and Industry

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#3 lore raw
Quoted 4 lines · Wolfram Sang

On Thu, Mar 13, 2008 at 06:07:45PM +0200, Darius wrote:

Hello,

Quoted 8 lines

(I know I am myself quite new here. I don't want to boast, just trying to be a little bit helpful.)

I found some things concerning the formal side:

Quoted 1 line

+ * History: 2002/2/07 use msgs[]

I have been told here that histories are not wanted as they are achieved through git.

ok, I'll remove history.

Quoted 8 lines

drivers/i2c/busses/i2c-imx.c line 172

Quoted 7 lines
drivers/i2c/busses/i2c-imx.c +6 -0
+static struct platform_driver i2c_imx_driver = {
+	.probe		= i2c_imx_probe,
+	.remove		= i2c_imx_remove,
+	.driver		= {
+		.name	= DRIVER_NAME,
+        .owner	= THIS_MODULE,

Indentation seems wrong here and in some other places...

stupid thing. It seems it's caused by Code::Blocks editor. I will correct text with simple text editor.

Quoted 10 lines

drivers/i2c/busses/i2c-imx.c line 184

Quoted 5 lines
drivers/i2c/busses/i2c-imx.c +4 -0
+struct imx_i2c_struct {
+    struct i2c_adapter  adapter;
+	struct resource		*res;
+	void   __iomem		*base;

...like here and so on.

drivers/i2c/busses/i2c-imx.c line 199

Quoted 3 lines
drivers/i2c/busses/i2c-imx.c +3 -0
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_bus_busy>\n");
+    #endif
Quoted 6 lines

Maybe you can define a debug-printing-macro that only prints when DEBUG_BUS is set and is simply empty when it is unset? This should make the code more readable, I think (or use pr_debug).

drivers/i2c/busses/i2c-imx.c line 502

Quoted 1 line
drivers/i2c/busses/i2c-imx.c +1 -0
+	// chech or i2c bus is not busy

CodingStyle suggests not using //.

this is from old driver code... I'll change it to /* */

Quoted 5 lines

All the best,

Wolfram

thanks for comments. What I should do with corrected patch? Place there again?

BR,
Darius

Quoted 7 lines

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#4 lore raw
Quoted 2 lines · Darius

thanks for comments. What I should do with corrected patch? Place there again?

Just send it again. You could add stuff like [PATCHV2] in the subject or a list of changes since the last revision in the description.

Bye,

Wolfram

Signature · 2 lines
  Dipl.-Ing. Wolfram Sang | http://www.pengutronix.de
 Pengutronix - Linux Solutions for Science and Industry

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#5 lore raw
In reply to Darius

Hi,

drivers/i2c/busses/i2c-imx.c line 199

Quoted 4 lines
drivers/i2c/busses/i2c-imx.c +3 -0
+    #ifdef CONFIG_I2C_DEBUG_BUS
+        printk("I2C: <i2c_imx_bus_busy>\n");
+    #endif

Using a macro that evaluates to nothing in case CONFIG_I2C_DEBUG_BUS is not defined would make the code much more readable.

drivers/i2c/busses/i2c-imx.c line 297

Quoted 3 lines
drivers/i2c/busses/i2c-imx.c +2 -0
+	temp = readb ( i2c_imx->base + IMX_I2C_I2CR);
+    temp |= I2CR_MSTA;

inconsistent indentation with tabs and spaces (througout the whole patch).

drivers/i2c/busses/i2c-imx.c line 595

Quoted 2 lines
drivers/i2c/busses/i2c-imx.c +2 -0
+	if (!i2c_imx) {
+		printk("I2C: can't allocate inteface!\n");

                                               ^^

typo.

Lothar Wassmann

Signature · 9 lines
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#6 lore raw
In reply to Darius
Quoted 5 lines · Darius

Almost written from scratch - only small piece of code leaved from old
driver, witch never was originally in vanilla kernel.
SMB is NOT supported currently.
Tested on the MXLADS v2.0 board with i2c client driver (driver for NT7651 LCD controller). All works fine, stable.

needs a signed-off-by line and --- separator

Quoted 10 lines

diff -uprN -X linux-2.6.24.3-vanilla/Documentation/dontdiff linux-2.6.24.3-vanilla/drivers/i2c/busses/i2c-imx.c linux-2.6.24.3/drivers/i2c/busses/i2c-imx.c
--- linux-2.6.24.3-vanilla/drivers/i2c/busses/i2c-imx.c 1970-01-01 03:00:00.000000000 +0300
+++ linux-2.6.24.3/drivers/i2c/busses/i2c-imx.c 2008-03-13 17:50:52.000000000 +0200
+/* These defines are missed in imx-regs.h */

 +#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 */

why put the defines in here if all the other register defines are in imx-regs.h?

Quoted 16 lines

+/* bits in IMX_I2C_I2SR register */

 +#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
 +
 +/* bits in IMX_I2C_I2CR register */
 +#define I2CR_RSTA      0x04
 +#define I2CR_TXAK      0x08
 +#define I2CR_MTX       0x10
 +#define I2CR_MSTA      0x20
 +#define I2CR_IIEN      0x40
 +#define I2CR_IEN       0x80

ditto above for the bit definitions

Quoted 1 line

+static struct i2c_imx_clk_div_pair i2c_imx_clk_div_tbl[64] = { /* FIXME */

...

Quoted 1 line

+};

anything with FIXME in comments probably should be addressed :-)

probably don't need the array size specifier

a reference to the datasheet page this table comes from would good (table 26-5 in the rev. 4 version of the ref. manual)

a note should mention the code depends on the entries being sorted with the dividers in order

structure can be marked as __init now as it no longer can be referenced at any time other than startup

Quoted 3 lines

+ #ifdef CONFIG_I2C_DEBUG_BUS
+ printk("I2C: <i2c_imx_bus_busy>\n");
+ #endif

dev_debug() would be a lot easier to read than this mess of #ifdefs

Quoted 1 line

+static int i2c_imx_set_clk (struct imx_i2c_struct *i2c_imx, unsigned int rate) {

function only gets called at init time, so add __init

Quoted 11 lines
 +       unsigned int hclk, sysclk;
 +       unsigned int desired_div;
 +       int i;
 +
 +    #ifdef CONFIG_I2C_DEBUG_BUS
 +        printk("I2C: <i2c_imx_set_clk>\n");
 +    #endif
 +
 +       sysclk = imx_get_system_clk ();
 +       hclk = imx_get_hclk();
 +       desired_div = (hclk << 1) / rate;
Quoted 3 lines

+ #ifdef CONFIG_I2C_DEBUG_BUS
+ printk("I2C: <i2c_imx_set_clk> SYSCLK=%d, HCLK=%d, DIV=%d\n", sysclk, hclk, desired_div);
+ #endif

printing desired_div here gives the wrong result - it's 2x what it should be.

Quoted 3 lines

+ if (desired_div & 0x01)
+ desired_div++;
+ desired_div >>= 1;

Should be printed here after rounding.

Quoted 8 lines

+ if (desired_div < 22)
+ desired_div = 22;
+ if (desired_div > 3840)
+ return -EINVAL;
+ for (i=0; i<64; i++) {
+ if (i2c_imx_clk_div_tbl[i].divider >= desired_div)
+ break;
+ }

should get rid of magic constants 64, 22, and 3840 - 64 is # entries in the table, 22 is smallest divisor and 3840 is largest divisor allowed by h/w.

Quoted 11 lines

+static int i2c_imx_xfer (struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) {
+

 +       int i, temp;
 +       int err = 0;
 +       struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);

+
+ #ifdef CONFIG_I2C_DEBUG_BUS
+ printk("I2C: <i2c_imx_xfer>\n");
+ #endif
+
+ // chech or i2c bus is not busy

c++ comment and misspelling

Quoted 47 lines

+ err = i2c_imx_bus_busy(i2c_imx);
+ if (err)
+ goto fail0;
+
+ // Enable i2c
+ i2c_imx_enable(i2c_imx);
+
+ /* Start I2C transfer */
+ i2c_imx_start (i2c_imx);
+
+ #ifdef CONFIG_I2C_DEBUG_BUS
+ temp = readb (i2c_imx->base + IMX_I2C_I2CR);
+ printk("I2C: <i2c_imx_xfer> CONTROL: IEN=%d, IIEN=%d, MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n",
+ (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);
+ printk("I2C: <i2c_imx_xfer> STATUS: ICF=%d, IAAS=%d, IBB=%d, IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n",
+ (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
+
+ // read/write data
+ for (i=0; i<num; i++) {
+
+ if (i) {
+ #ifdef CONFIG_I2C_DEBUG_BUS
+ printk("I2C: <i2c_imx_read> repeated start\n");

 +            #endif
 +            temp = readb(i2c_imx->base + IMX_I2C_I2CR);
 +            temp |= I2CR_RSTA;
 +            writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
 +               }
 +               #ifdef CONFIG_I2C_DEBUG_BUS
 +            printk("I2C: <i2c_imx_xfer> transfer message: %d\n", i);
 +        #endif
 +               /* write/read data */
 +               if (!(msgs[i].flags & I2C_M_RD))
 +                       err = i2c_imx_write (i2c_imx, &msgs[i]);
 +               else
 +            err = i2c_imx_read  (i2c_imx, &msgs[i]);
 +       }
 +
 +fail0:
 +       /* Stop bus */
 +       i2c_imx_stop (i2c_imx);
 +       /* disable i2c bus */
 +       i2c_imx_disable (i2c_imx);
Quoted 2 lines

+ #ifdef CONFIG_I2C_DEBUG_BUS
+ printk("I2C: <i2c_imx_xfer> exit with: %s: %d\n", (err < 0)?"error":"succes msg", (err < 0)?err:num);

misspelling - success

Quoted 20 lines

+ #endif
+ return (err < 0) ? err : num;
+}
+
+static u32 i2c_imx_func (struct i2c_adapter *adapter) {
+ return I2C_FUNC_I2C;
+}
+
+static int __init i2c_imx_probe (struct platform_device *pdev) { +

 +    struct imx_i2c_struct *i2c_imx;
 +    struct resource *res;
 +    void   __iomem     *base;
 +    int irq;
 +       int res_size;
 +       int ret;
 +
 +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 +       irq = platform_get_irq(pdev, 0);
 +       if (!res) {
Quoted 1 line

+ printk("I2C: can't get device resources!\n");

should probably use dev_err macro for these error messages

Quoted 22 lines

+ return -ENODEV;
+ }
+ if (irq < 0) {
+ printk("I2C: can't get irq number!\n");
+ return -ENODEV;
+ }
+
+ res_size = (res->end) - (res->start) + 1;
+ if (!request_mem_region(res->start, res_size, res->name)) {
+ printk("I2C: can't allocate %d bytes at %d address!\n", res_size, res->start);
+ return -ENOMEM;
+ }
+
+ base = ioremap (res->start, res_size);
+ if (!base) {
+ printk("I2C: ioremap failed!\n");
+ ret = -EIO;
+ goto fail0;
+ }
+
+ i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
+ if (!i2c_imx) {

Quoted 6 lines
 +               printk("I2C: can't allocate inteface!\n");
 +               ret = -ENOMEM;
 +               goto fail1;

+ }
+
+ // Setup i2c_imx driver structure

c++ comment

Quoted 3 lines

+
+ printk("I2C: %s: IMX I2C adapter registered\n", i2c_imx->adapter.dev.bus_id);
+ return 0; // Return OK */

mixed c++ and normal comment?

Quoted 6 lines

--- linux-2.6.24.3-vanilla/drivers/i2c/busses/Kconfig 2008-01-25 00:58:37.000000000 +0200
+++ linux-2.6.24.3/drivers/i2c/busses/Kconfig 2008-03-13 17:29:43.000000000 +0200
@@ -249,6 +249,16 @@ config I2C_IBM_IIC
This driver can also be built as a module. If so, the module will be called i2c-ibm_iic.

Quoted 6 lines

+config I2C_IMX

 +       tristate "IMX I2C interface"
 +       depends on ARCH_IMX
 +       help

+ Say Y here if you want to use the IIC bus controller on
+ the Freescale IMX processors.

it's i.MX - I think this will only work with i.MX1, i.MXL, and i.MXS. I think the i.MX21, 21S, 27, and 31 are a bit different.

Signature · 7 lines
Hardware, n.:
 The parts of a computer system that can be kicked.

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#8 lore raw
Quoted 10 lines · Andrew Dyer
Quoted 5 lines · Darius

Almost written from scratch - only small piece of code leaved from old
driver, witch never was originally in vanilla kernel.
SMB is NOT supported currently.
Tested on the MXLADS v2.0 board with i2c client driver (driver for NT7651 LCD controller). All works fine, stable.

needs a signed-off-by line and --- separator

thank you. I'll correct all errors. About clock setup at init time - I'll review this part in near future, because no time for this now. I can remove this part from patch (set default clock 100khz) or leave all as is. What is better?

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#9 lore raw
In reply to Darius

Hi Darius,

Quoted 3 lines · Darius

Almost written from scratch - only small piece of code leaved from old driver, witch never was originally in vanilla kernel.
SMB is NOT supported currently.

Assuming that you mean SMBus, it is in fact almost supported, because i2c-core can emulate most of SMBus over I2C. Just add I2C_FUNC_SMBUS_EMUL to i2c_imx_func() and you're done. If the device doesn't support zero-byte messages, you might have to remove I2C_FUNC_SMBUS_QUICK but that's about it.

Quoted 2 lines

Tested on the MXLADS v2.0 board with i2c client driver (driver for NT7651 LCD controller). All works fine, stable.

You really need to read Documentation/CodingStyle and adjust your code accordingly before I will consider merging your patch. scripts/checkpatch.pl is your friend too.

Signature · 6 lines
Jean Delvare

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