On Tue, May 20, 2008 at 09:41:59AM +0300, Darius wrote:
> Changes from V5 version:
>
> - Trent Piepho suggestions added (except debug macro)
> - Debug printing fixed
> - Calculations of clock divider and delay improved
>
> Checked with checkpatch.pl again and tested on MXLADS V2.0 board with several
> i2c clients.
>
> Signed-off-by: Darius Augulis <[EMAIL PROTECTED]>
> ---
> Index: linux-2.6.26-rc1/arch/arm/mach-imx/mx1ads.c
> ===================================================================
> --- linux-2.6.26-rc1.orig/arch/arm/mach-imx/mx1ads.c
> +++ linux-2.6.26-rc1/arch/arm/mach-imx/mx1ads.c
> @@ -109,10 +109,31 @@ static struct platform_device imx_uart2_
> }
> };
>
> +static struct resource imx_i2c_resources[] = {
> + [0] = {
> + .start = 0x00217000,
> + .end = 0x00217010,
> + .flags = IORESOURCE_MEM,
> + },
> + [1] = {
> + .start = I2C_INT,
> + .end = I2C_INT,
> + .flags = IORESOURCE_IRQ,
> + },
> +};
> +
> +static struct platform_device imx_i2c_device = {
> + .name = "imx-i2c",
> + .id = 0,
> + .resource = imx_i2c_resources,
> + .num_resources = ARRAY_SIZE(imx_i2c_resources),
> +};
> +
> static struct platform_device *devices[] __initdata = {
> &cs89x0_device,
> &imx_uart1_device,
> &imx_uart2_device,
> + &imx_i2c_device,
> };
>
> #ifdef CONFIG_MMC_IMX
> Index: linux-2.6.26-rc1/drivers/i2c/busses/i2c-imx.c
> ===================================================================
> --- /dev/null
> +++ linux-2.6.26-rc1/drivers/i2c/busses/i2c-imx.c
> @@ -0,0 +1,639 @@
> +/*
> + * 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
> + * Driver for I2C Bus integrated in i.MXL, i.MX1
> + *
> + * module parameters:
> + * - clkfreq:
> + * Sets the desired clock rate
> + * The default value is 100000
> + * Max value is 400000
> + * - imxslave:
> + * IMX slave I2C address in decimal format
> + * The default value is 0xAC in hex
> + *
> + * Derived from Motorola GSG China I2C example driver
> + *
> + * 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.
> <adyeratrighthandtech.com>
> + * 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/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/io.h>
> +#include <linux/platform_device.h>
> +#include <asm/arch/irqs.h>
> +#include <asm/arch/hardware.h>
> +#include <asm/arch/imx-regs.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 /* 100kHz */
> +
> +/* Timeouts */
> +#define I2C_IMX_TIME_BUSY 2000 /* loop count */
> +#define I2C_IMX_TIME_ACK 2000 /* loop count */
> +#define I2C_IMX_TIME_TRX 5 /* seconds */
> +
> +/* 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
> +
> +/* 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
> +
> +/** 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 i2c_imx_probe(struct platform_device *pdev);
> +static int i2c_imx_remove(struct platform_device *pdev);
Really you shouldn't need to be declaring these up front if the code
is easily re-orderable to avoid it.
> +/** Variables
> ******************************************************************
> +*******************************************************************************/
> +
> +static unsigned int clkfreq = IMX_I2C_BIT_RATE;
> +static unsigned int imxslave = IMX_I2C_SLAVE_ADDR;
> +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_imx_clk_divider [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 }
> +};
> +
> +static struct platform_driver i2c_imx_driver = {
> + .probe = i2c_imx_probe,
> + .remove = i2c_imx_remove,
> + .driver = {
> + .name = DRIVER_NAME,
> + .owner = THIS_MODULE,
> + }
> +};
No suspend/resume support? See above note on ordering.
> +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;
> +
> + dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
> +
> + /* 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);
> + }
> + dev_dbg(&i2c_imx->adapter.dev, "<%s> I2C bus is busy!\n", __func__);
> + return -I2C_IMX_ERR_BUSY;
> +}
> +
> +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), I2C_IMX_TIME_TRX * HZ);
> +
> + 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 -I2C_IMX_ERR_TX_TIMEOUT;
> + }
> + 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)
> +{
> + unsigned int i = 0;
> +
> + for (i = 0; i < I2C_IMX_TIME_ACK; i++) {
> + if (!(readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_RXAK)) {
> + dev_dbg(&i2c_imx->adapter.dev,
> + "<%s> ACK received\n", __func__);
> + return 0;
> + }
> + udelay(1);
> + }
> + dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK!\n", __func__);
> + return -I2C_IMX_ERR_RX_NO_ACK; /* No ACK */
> +}
> +
> +static void i2c_imx_enable(struct imx_i2c_struct *i2c_imx)
> +{
> + dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
> + writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
> +}
> +
> +static void i2c_imx_disable(struct imx_i2c_struct *i2c_imx)
> +{
> + dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
> +
> + /* 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);
> + writeb(0, i2c_imx->base + IMX_I2C_I2CR);
> +}
> +
> +static void i2c_imx_start(struct imx_i2c_struct *i2c_imx)
> +{
> + unsigned int temp = 0;
> +
> + 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);
> + 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;
> +
> + 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);
> +}
> +
> +static int __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx, unsigned
> int rate)
> +{
> + unsigned int hclk;
> +#ifdef CONFIG_I2C_DEBUG_BUS
> + unsigned int sysclk;
> +#endif
> + unsigned int desired_div;
> + int i;
> +
> + /* Divider value calculation */
> + hclk = imx_get_hclk();
> + desired_div = (hclk + rate - 1) / rate;
> + if (desired_div < i2c_imx_clk_divider[0][0])
> + i = 0;
> + else if (desired_div >
> i2c_imx_clk_divider[ARRAY_SIZE(i2c_imx_clk_divider)-1][0])
> + i = ARRAY_SIZE(i2c_imx_clk_divider) - 1;
> + else
> + for (i = 0; i2c_imx_clk_divider[i][0] < desired_div; i++);
> +
> + /* Write divider value to register */
> + writeb(i2c_imx_clk_divider[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_imx_clk_divider[i][0]
> + + (hclk / 2) - 1) / (hclk / 2);
> +
> + /* dev_dbg() can't be used, because adapter is not yet registered */
> +#ifdef CONFIG_I2C_DEBUG_BUS
> + sysclk = imx_get_system_clk();
> + printk(KERN_DEBUG "I2C: <%s> SYSCLK=%d, HCLK=%d, REQ DIV=%d\n",
> + __func__, sysclk, hclk, desired_div);
> + printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n", __func__,
> + i2c_imx_clk_divider[i][1], i2c_imx_clk_divider[i][0]);
> +#endif
> + return 0;
> +}
> +
> +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
> + 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));
> +#else
> + temp = readb(i2c_imx->base + IMX_I2C_I2SR);
> +#endif
this looks like an idea candidate for an inline debug function
to avoid ifdefs like this in the main code paths.
> + 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);
> + }
minor style point, blank line would have bee nnice here/
> + return IRQ_HANDLED;
> +}
> +
> +static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg
> *msgs)
> +{
> + int i;
> +
> + dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
> + __func__, (msgs->addr));
> +
> + /* write slave address */
> + writeb((msgs->addr), 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;
> + 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);
> + 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;
> +
> + dev_dbg(&i2c_imx->adapter.dev,
> + "<%s> write slave address: addr=0x%x\n", __func__,
> + ((msgs->addr)|0x01));
> +
> + /* write slave address */
> + writeb(((msgs->addr)|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;
> +
> + 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++) {
> + if (i2c_imx_trx_complete(i2c_imx))
> + return -I2C_IMX_ERR_RX_TIMEOUT;
> + 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)
> +{
> + int i, temp;
> + int err = 0;
> + 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 */
> + 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);
> +
> + temp = readb(i2c_imx->base + IMX_I2C_I2CR);
> +
> + /* 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 */
> + 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);
> + dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
> + (err < 0) ? "error" : "success msg", (err < 0) ? err : num);
> + return (err < 0) ? err : num;
> +}
> +
> +static u32 i2c_imx_func(struct i2c_adapter *adapter)
> +{
> + return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL);
> +}
> +
> +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;
> +
> + dev_dbg(&pdev->dev, "<%s>\n", __func__);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + irq = platform_get_irq(pdev, 0);
> + if (!res) {
> + dev_err(&pdev->dev, "can't get device resources!\n");
> + return -ENODEV;
> + }
> + if (irq < 0) {
> + dev_err(&pdev->dev, "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)) {
> + dev_err(&pdev->dev, "can't allocate %d bytes at %d address!\n",
> + res_size, res->start);
> + return -ENOMEM;
> + }
> + 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.class = I2C_CLASS_HWMON;
> + i2c_imx->adapter.nr = pdev->id;
> + 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) {
> + dev_err(&pdev->dev, "cannot claim irq %d !\n", i2c_imx->irq);
> + goto fail2;
> + }
> +
> + /* Set up adapter data */
> + i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
> +
> + /* 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);
> +
> +
> + /* Add I2C adapter */
> + ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "registration failed\n");
> + goto fail3;
> + }
> +
> + 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");
> + dev_dbg(&i2c_imx->adapter.dev,
> + "adapter \"%s\" associated with driver \"%s\"\n",
> + i2c_imx->adapter.dev.bus_id, i2c_imx_driver.driver.name);
> + 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 */
> + 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);
> +
> + /* 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_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");
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Darius Augulis");
> +MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
> +MODULE_ALIAS("platform:" DRIVER_NAME);
> Index: linux-2.6.26-rc1/drivers/i2c/busses/Kconfig
> ===================================================================
> --- linux-2.6.26-rc1.orig/drivers/i2c/busses/Kconfig
> +++ linux-2.6.26-rc1/drivers/i2c/busses/Kconfig
> @@ -257,6 +257,16 @@ 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 i.MXL and i.MX1 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-2.6.26-rc1/drivers/i2c/busses/Makefile
> ===================================================================
> --- linux-2.6.26-rc1.orig/drivers/i2c/busses/Makefile
> +++ linux-2.6.26-rc1/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_POWERMAC) += i2c-powermac.o
This is looking much better, my only concerns are the code is
a too tightly packed in places (style) and there are avoidable
ifdefs in pieces of code that could be move elsewhere.
--
Ben ([EMAIL PROTECTED], http://www.fluff.org/)
'a smiley only costs 4 bytes'
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