drivers/i2c/busses/i2c-mpc.c - arm/linux-arm64-legacy - Git at Google

 /*
  * (C) Copyright 2003-2004
  * Humboldt Solutions Ltd, adrian@humboldt.co.uk.

  * This is a combined i2c adapter and algorithm driver for the
  * MPC107/Tsi107 PowerPC northbridge and processors that include
  * the same I2C unit (8240, 8245, 85xx).
  *
  * Release 0.8
  *
  * This file is licensed under the terms of the GNU General Public
  * License version 2. This program is licensed "as is" without any
  * warranty of any kind, whether express or implied.
  */

 #include <linux/config.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/init.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>

 #include <asm/io.h>
 #include <linux/fsl_devices.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>

 #define MPC_I2C_ADDR  0x00
 #define MPC_I2C_FDR 	0x04
 #define MPC_I2C_CR	0x08
 #define MPC_I2C_SR	0x0c
 #define MPC_I2C_DR	0x10
 #define MPC_I2C_DFSRR 0x14
 #define MPC_I2C_REGION 0x20

 #define CCR_MEN  0x80
 #define CCR_MIEN 0x40
 #define CCR_MSTA 0x20
 #define CCR_MTX  0x10
 #define CCR_TXAK 0x08
 #define CCR_RSTA 0x04

 #define CSR_MCF  0x80
 #define CSR_MAAS 0x40
 #define CSR_MBB  0x20
 #define CSR_MAL  0x10
 #define CSR_SRW  0x04
 #define CSR_MIF  0x02
 #define CSR_RXAK 0x01

 struct mpc_i2c {
 	void __iomem *base;
 	u32 interrupt;
 	wait_queue_head_t queue;
 	struct i2c_adapter adap;
 	int irq;
 	u32 flags;
 };

 static __inline__ void writeccr(struct mpc_i2c *i2c, u32 x)
 {
 	writeb(x, i2c->base + MPC_I2C_CR);
 }

 static irqreturn_t mpc_i2c_isr(int irq, void *dev_id, struct pt_regs *regs)
 {
 	struct mpc_i2c *i2c = dev_id;
 	if (readb(i2c->base + MPC_I2C_SR) & CSR_MIF) {
 		/* Read again to allow register to stabilise */
 		i2c->interrupt = readb(i2c->base + MPC_I2C_SR);
 		writeb(0, i2c->base + MPC_I2C_SR);
 		wake_up_interruptible(&i2c->queue);
 	}
 	return IRQ_HANDLED;
 }

 static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
 {
 	unsigned long orig_jiffies = jiffies;
 	u32 x;
 	int result = 0;

 	if (i2c->irq == 0)
 	{
 		while (!(readb(i2c->base + MPC_I2C_SR) & CSR_MIF)) {
 			schedule();
 			if (time_after(jiffies, orig_jiffies + timeout)) {
 				pr_debug("I2C: timeout\n");
 				result = -EIO;
 				break;
 			}
 		}
 		x = readb(i2c->base + MPC_I2C_SR);
 		writeb(0, i2c->base + MPC_I2C_SR);
 	} else {
 		/* Interrupt mode */
 		result = wait_event_interruptible_timeout(i2c->queue,
 			(i2c->interrupt & CSR_MIF), timeout * HZ);

 		if (unlikely(result < 0))
 			pr_debug("I2C: wait interrupted\n");
 		else if (unlikely(!(i2c->interrupt & CSR_MIF))) {
 			pr_debug("I2C: wait timeout\n");
 			result = -ETIMEDOUT;
 		}

 		x = i2c->interrupt;
 		i2c->interrupt = 0;
 	}

 	if (result < 0)
 		return result;

 	if (!(x & CSR_MCF)) {
 		pr_debug("I2C: unfinished\n");
 		return -EIO;
 	}

 	if (x & CSR_MAL) {
 		pr_debug("I2C: MAL\n");
 		return -EIO;
 	}

 	if (writing && (x & CSR_RXAK)) {
 		pr_debug("I2C: No RXAK\n");
 		/* generate stop */
 		writeccr(i2c, CCR_MEN);
 		return -EIO;
 	}
 	return 0;
 }

 static void mpc_i2c_setclock(struct mpc_i2c *i2c)
 {
 	/* Set clock and filters */
 	if (i2c->flags & FSL_I2C_DEV_SEPARATE_DFSRR) {
 		writeb(0x31, i2c->base + MPC_I2C_FDR);
 		writeb(0x10, i2c->base + MPC_I2C_DFSRR);
 	} else if (i2c->flags & FSL_I2C_DEV_CLOCK_5200)
 		writeb(0x3f, i2c->base + MPC_I2C_FDR);
 	else
 		writel(0x1031, i2c->base + MPC_I2C_FDR);
 }

 static void mpc_i2c_start(struct mpc_i2c *i2c)
 {
 	/* Clear arbitration */
 	writeb(0, i2c->base + MPC_I2C_SR);
 	/* Start with MEN */
 	writeccr(i2c, CCR_MEN);
 }

 static void mpc_i2c_stop(struct mpc_i2c *i2c)
 {
 	writeccr(i2c, CCR_MEN);
 }

 static int mpc_write(struct mpc_i2c *i2c, int target,
 		     const u8 * data, int length, int restart)
 {
 	int i;
 	unsigned timeout = i2c->adap.timeout;
 	u32 flags = restart ? CCR_RSTA : 0;

 	/* Start with MEN */
 	if (!restart)
 		writeccr(i2c, CCR_MEN);
 	/* Start as master */
 	writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
 	/* Write target byte */
 	writeb((target << 1), i2c->base + MPC_I2C_DR);

 	if (i2c_wait(i2c, timeout, 1) < 0)
 		return -1;

 	for (i = 0; i < length; i++) {
 		/* Write data byte */
 		writeb(data[i], i2c->base + MPC_I2C_DR);

 		if (i2c_wait(i2c, timeout, 1) < 0)
 			return -1;
 	}

 	return 0;
 }

 static int mpc_read(struct mpc_i2c *i2c, int target,
 		    u8 * data, int length, int restart)
 {
 	unsigned timeout = i2c->adap.timeout;
 	int i;
 	u32 flags = restart ? CCR_RSTA : 0;

 	/* Start with MEN */
 	if (!restart)
 		writeccr(i2c, CCR_MEN);
 	/* Switch to read - restart */
 	writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
 	/* Write target address byte - this time with the read flag set */
 	writeb((target << 1) | 1, i2c->base + MPC_I2C_DR);

 	if (i2c_wait(i2c, timeout, 1) < 0)
 		return -1;

 	if (length) {
 		if (length == 1)
 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
 		else
 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
 		/* Dummy read */
 		readb(i2c->base + MPC_I2C_DR);
 	}

 	for (i = 0; i < length; i++) {
 		if (i2c_wait(i2c, timeout, 0) < 0)
 			return -1;

 		/* Generate txack on next to last byte */
 		if (i == length - 2)
 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
 		/* Generate stop on last byte */
 		if (i == length - 1)
 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_TXAK);
 		data[i] = readb(i2c->base + MPC_I2C_DR);
 	}

 	return length;
 }

 static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 {
 	struct i2c_msg *pmsg;
 	int i;
 	int ret = 0;
 	unsigned long orig_jiffies = jiffies;
 	struct mpc_i2c *i2c = i2c_get_adapdata(adap);

 	mpc_i2c_start(i2c);

 	/* Allow bus up to 1s to become not busy */
 	while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
 		if (signal_pending(current)) {
 			pr_debug("I2C: Interrupted\n");
 			return -EINTR;
 		}
 		if (time_after(jiffies, orig_jiffies + HZ)) {
 			pr_debug("I2C: timeout\n");
 			return -EIO;
 		}
 		schedule();
 	}

 	for (i = 0; ret >= 0 && i < num; i++) {
 		pmsg = &msgs[i];
 		pr_debug("Doing %s %d bytes to 0x%02x - %d of %d messages\n",
 			 pmsg->flags & I2C_M_RD ? "read" : "write",
 			 pmsg->len, pmsg->addr, i + 1, num);
 		if (pmsg->flags & I2C_M_RD)
 			ret =
 			    mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
 		else
 			ret =
 			    mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
 	}
 	mpc_i2c_stop(i2c);
 	return (ret < 0) ? ret : num;
 }

 static u32 mpc_functionality(struct i2c_adapter *adap)
 {
 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 }

 static struct i2c_algorithm mpc_algo = {
 	.master_xfer = mpc_xfer,
 	.functionality = mpc_functionality,
 };

 static struct i2c_adapter mpc_ops = {
 	.owner = THIS_MODULE,
 	.name = "MPC adapter",
 	.id = I2C_HW_MPC107,
 	.algo = &mpc_algo,
 	.class = I2C_CLASS_HWMON,
 	.timeout = 1,
 	.retries = 1
 };

 static int fsl_i2c_probe(struct device *device)
 {
 	int result = 0;
 	struct mpc_i2c *i2c;
 	struct platform_device *pdev = to_platform_device(device);
 	struct fsl_i2c_platform_data *pdata;
 	struct resource *r = platform_get_resource(pdev, IORESOURCE_MEM, 0);

 	pdata = (struct fsl_i2c_platform_data *) pdev->dev.platform_data;

 	if (!(i2c = kzalloc(sizeof(*i2c), GFP_KERNEL))) {
 		return -ENOMEM;
 	}

 	i2c->irq = platform_get_irq(pdev, 0);
 	i2c->flags = pdata->device_flags;
 	init_waitqueue_head(&i2c->queue);

 	i2c->base = ioremap((phys_addr_t)r->start, MPC_I2C_REGION);

 	if (!i2c->base) {
 		printk(KERN_ERR "i2c-mpc - failed to map controller\n");
 		result = -ENOMEM;
 		goto fail_map;
 	}

 	if (i2c->irq != 0)
 		if ((result = request_irq(i2c->irq, mpc_i2c_isr,
 					  SA_SHIRQ, "i2c-mpc", i2c)) < 0) {
 			printk(KERN_ERR
 			       "i2c-mpc - failed to attach interrupt\n");
 			goto fail_irq;
 		}

 	mpc_i2c_setclock(i2c);
 	dev_set_drvdata(device, i2c);

 	i2c->adap = mpc_ops;
 	i2c_set_adapdata(&i2c->adap, i2c);
 	i2c->adap.dev.parent = &pdev->dev;
 	if ((result = i2c_add_adapter(&i2c->adap)) < 0) {
 		printk(KERN_ERR "i2c-mpc - failed to add adapter\n");
 		goto fail_add;
 	}

 	return result;

       fail_add:
 	if (i2c->irq != 0)
 		free_irq(i2c->irq, NULL);
       fail_irq:
 	iounmap(i2c->base);
       fail_map:
 	kfree(i2c);
 	return result;
 };

 static int fsl_i2c_remove(struct device *device)
 {
 	struct mpc_i2c *i2c = dev_get_drvdata(device);

 	i2c_del_adapter(&i2c->adap);
 	dev_set_drvdata(device, NULL);

 	if (i2c->irq != 0)
 		free_irq(i2c->irq, i2c);

 	iounmap(i2c->base);
 	kfree(i2c);
 	return 0;
 };

 /* Structure for a device driver */
 static struct device_driver fsl_i2c_driver = {
 	.owner = THIS_MODULE,
 	.name = "fsl-i2c",
 	.bus = &platform_bus_type,
 	.probe = fsl_i2c_probe,
 	.remove = fsl_i2c_remove,
 };

 static int __init fsl_i2c_init(void)
 {
 	return driver_register(&fsl_i2c_driver);
 }

 static void __exit fsl_i2c_exit(void)
 {
 	driver_unregister(&fsl_i2c_driver);
 }

 module_init(fsl_i2c_init);
 module_exit(fsl_i2c_exit);

 MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
 MODULE_DESCRIPTION
     ("I2C-Bus adapter for MPC107 bridge and MPC824x/85xx/52xx processors");
 MODULE_LICENSE("GPL");
	/*
	* (C) Copyright 2003-2004
	* Humboldt Solutions Ltd, adrian@humboldt.co.uk.

	* This is a combined i2c adapter and algorithm driver for the
	* MPC107/Tsi107 PowerPC northbridge and processors that include
	* the same I2C unit (8240, 8245, 85xx).
	*
	* Release 0.8
	*
	* This file is licensed under the terms of the GNU General Public
	* License version 2. This program is licensed "as is" without any
	* warranty of any kind, whether express or implied.
	*/

	#include <linux/config.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/sched.h>
	#include <linux/init.h>
	#include <linux/pci.h>
	#include <linux/platform_device.h>

	#include <asm/io.h>
	#include <linux/fsl_devices.h>
	#include <linux/i2c.h>
	#include <linux/interrupt.h>
	#include <linux/delay.h>

	#define MPC_I2C_ADDR 0x00
	#define MPC_I2C_FDR 0x04
	#define MPC_I2C_CR 0x08
	#define MPC_I2C_SR 0x0c
	#define MPC_I2C_DR 0x10
	#define MPC_I2C_DFSRR 0x14
	#define MPC_I2C_REGION 0x20

	#define CCR_MEN 0x80
	#define CCR_MIEN 0x40
	#define CCR_MSTA 0x20
	#define CCR_MTX 0x10
	#define CCR_TXAK 0x08
	#define CCR_RSTA 0x04

	#define CSR_MCF 0x80
	#define CSR_MAAS 0x40
	#define CSR_MBB 0x20
	#define CSR_MAL 0x10
	#define CSR_SRW 0x04
	#define CSR_MIF 0x02
	#define CSR_RXAK 0x01

	struct mpc_i2c {
	void __iomem *base;
	u32 interrupt;
	wait_queue_head_t queue;
	struct i2c_adapter adap;
	int irq;
	u32 flags;
	};

	static __inline__ void writeccr(struct mpc_i2c *i2c, u32 x)
	{
	writeb(x, i2c->base + MPC_I2C_CR);
	}

	static irqreturn_t mpc_i2c_isr(int irq, void dev_id, struct pt_regs regs)
	{
	struct mpc_i2c *i2c = dev_id;
	if (readb(i2c->base + MPC_I2C_SR) & CSR_MIF) {
	/* Read again to allow register to stabilise */
	i2c->interrupt = readb(i2c->base + MPC_I2C_SR);
	writeb(0, i2c->base + MPC_I2C_SR);
	wake_up_interruptible(&i2c->queue);
	}
	return IRQ_HANDLED;
	}

	static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
	{
	unsigned long orig_jiffies = jiffies;
	u32 x;
	int result = 0;

	if (i2c->irq == 0)
	{
	while (!(readb(i2c->base + MPC_I2C_SR) & CSR_MIF)) {
	schedule();
	if (time_after(jiffies, orig_jiffies + timeout)) {
	pr_debug("I2C: timeout\n");
	result = -EIO;
	break;
	}
	}
	x = readb(i2c->base + MPC_I2C_SR);
	writeb(0, i2c->base + MPC_I2C_SR);
	} else {
	/* Interrupt mode */
	result = wait_event_interruptible_timeout(i2c->queue,
	(i2c->interrupt & CSR_MIF), timeout * HZ);

	if (unlikely(result < 0))
	pr_debug("I2C: wait interrupted\n");
	else if (unlikely(!(i2c->interrupt & CSR_MIF))) {
	pr_debug("I2C: wait timeout\n");
	result = -ETIMEDOUT;
	}

	x = i2c->interrupt;
	i2c->interrupt = 0;
	}

	if (result < 0)
	return result;

	if (!(x & CSR_MCF)) {
	pr_debug("I2C: unfinished\n");
	return -EIO;
	}

	if (x & CSR_MAL) {
	pr_debug("I2C: MAL\n");
	return -EIO;
	}

	if (writing && (x & CSR_RXAK)) {
	pr_debug("I2C: No RXAK\n");
	/* generate stop */
	writeccr(i2c, CCR_MEN);
	return -EIO;
	}
	return 0;
	}

	static void mpc_i2c_setclock(struct mpc_i2c *i2c)
	{
	/* Set clock and filters */
	if (i2c->flags & FSL_I2C_DEV_SEPARATE_DFSRR) {
	writeb(0x31, i2c->base + MPC_I2C_FDR);
	writeb(0x10, i2c->base + MPC_I2C_DFSRR);
	} else if (i2c->flags & FSL_I2C_DEV_CLOCK_5200)
	writeb(0x3f, i2c->base + MPC_I2C_FDR);
	else
	writel(0x1031, i2c->base + MPC_I2C_FDR);
	}

	static void mpc_i2c_start(struct mpc_i2c *i2c)
	{
	/* Clear arbitration */
	writeb(0, i2c->base + MPC_I2C_SR);
	/* Start with MEN */
	writeccr(i2c, CCR_MEN);
	}

	static void mpc_i2c_stop(struct mpc_i2c *i2c)
	{
	writeccr(i2c, CCR_MEN);
	}

	static int mpc_write(struct mpc_i2c *i2c, int target,
	const u8 * data, int length, int restart)
	{
	int i;
	unsigned timeout = i2c->adap.timeout;
	u32 flags = restart ? CCR_RSTA : 0;

	/* Start with MEN */
	if (!restart)
	writeccr(i2c, CCR_MEN);
	/* Start as master */
	writeccr(i2c, CCR_MIEN \| CCR_MEN \| CCR_MSTA \| CCR_MTX \| flags);
	/* Write target byte */
	writeb((target << 1), i2c->base + MPC_I2C_DR);

	if (i2c_wait(i2c, timeout, 1) < 0)
	return -1;

	for (i = 0; i < length; i++) {
	/* Write data byte */
	writeb(data[i], i2c->base + MPC_I2C_DR);

	if (i2c_wait(i2c, timeout, 1) < 0)
	return -1;
	}

	return 0;
	}

	static int mpc_read(struct mpc_i2c *i2c, int target,
	u8 * data, int length, int restart)
	{
	unsigned timeout = i2c->adap.timeout;
	int i;
	u32 flags = restart ? CCR_RSTA : 0;

	/* Start with MEN */
	if (!restart)
	writeccr(i2c, CCR_MEN);
	/* Switch to read - restart */
	writeccr(i2c, CCR_MIEN \| CCR_MEN \| CCR_MSTA \| CCR_MTX \| flags);
	/* Write target address byte - this time with the read flag set */
	writeb((target << 1) \| 1, i2c->base + MPC_I2C_DR);

	if (i2c_wait(i2c, timeout, 1) < 0)
	return -1;

	if (length) {
	if (length == 1)
	writeccr(i2c, CCR_MIEN \| CCR_MEN \| CCR_MSTA \| CCR_TXAK);
	else
	writeccr(i2c, CCR_MIEN \| CCR_MEN \| CCR_MSTA);
	/* Dummy read */
	readb(i2c->base + MPC_I2C_DR);
	}

	for (i = 0; i < length; i++) {
	if (i2c_wait(i2c, timeout, 0) < 0)
	return -1;

	/* Generate txack on next to last byte */
	if (i == length - 2)
	writeccr(i2c, CCR_MIEN \| CCR_MEN \| CCR_MSTA \| CCR_TXAK);
	/* Generate stop on last byte */
	if (i == length - 1)
	writeccr(i2c, CCR_MIEN \| CCR_MEN \| CCR_TXAK);
	data[i] = readb(i2c->base + MPC_I2C_DR);
	}

	return length;
	}

	static int mpc_xfer(struct i2c_adapter adap, struct i2c_msg msgs, int num)
	{
	struct i2c_msg *pmsg;
	int i;
	int ret = 0;
	unsigned long orig_jiffies = jiffies;
	struct mpc_i2c *i2c = i2c_get_adapdata(adap);

	mpc_i2c_start(i2c);

	/* Allow bus up to 1s to become not busy */
	while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
	if (signal_pending(current)) {
	pr_debug("I2C: Interrupted\n");
	return -EINTR;
	}
	if (time_after(jiffies, orig_jiffies + HZ)) {
	pr_debug("I2C: timeout\n");
	return -EIO;
	}
	schedule();
	}

	for (i = 0; ret >= 0 && i < num; i++) {
	pmsg = &msgs[i];
	pr_debug("Doing %s %d bytes to 0x%02x - %d of %d messages\n",
	pmsg->flags & I2C_M_RD ? "read" : "write",
	pmsg->len, pmsg->addr, i + 1, num);
	if (pmsg->flags & I2C_M_RD)
	ret =
	mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
	else
	ret =
	mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
	}
	mpc_i2c_stop(i2c);
	return (ret < 0) ? ret : num;
	}

	static u32 mpc_functionality(struct i2c_adapter *adap)
	{
	return I2C_FUNC_I2C \| I2C_FUNC_SMBUS_EMUL;
	}

	static struct i2c_algorithm mpc_algo = {
	.master_xfer = mpc_xfer,
	.functionality = mpc_functionality,
	};

	static struct i2c_adapter mpc_ops = {
	.owner = THIS_MODULE,
	.name = "MPC adapter",
	.id = I2C_HW_MPC107,
	.algo = &mpc_algo,
	.class = I2C_CLASS_HWMON,
	.timeout = 1,
	.retries = 1
	};

	static int fsl_i2c_probe(struct device *device)
	{
	int result = 0;
	struct mpc_i2c *i2c;
	struct platform_device *pdev = to_platform_device(device);
	struct fsl_i2c_platform_data *pdata;
	struct resource *r = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	pdata = (struct fsl_i2c_platform_data *) pdev->dev.platform_data;

	if (!(i2c = kzalloc(sizeof(*i2c), GFP_KERNEL))) {
	return -ENOMEM;
	}

	i2c->irq = platform_get_irq(pdev, 0);
	i2c->flags = pdata->device_flags;
	init_waitqueue_head(&i2c->queue);

	i2c->base = ioremap((phys_addr_t)r->start, MPC_I2C_REGION);

	if (!i2c->base) {
	printk(KERN_ERR "i2c-mpc - failed to map controller\n");
	result = -ENOMEM;
	goto fail_map;
	}

	if (i2c->irq != 0)
	if ((result = request_irq(i2c->irq, mpc_i2c_isr,
	SA_SHIRQ, "i2c-mpc", i2c)) < 0) {
	printk(KERN_ERR
	"i2c-mpc - failed to attach interrupt\n");
	goto fail_irq;
	}

	mpc_i2c_setclock(i2c);
	dev_set_drvdata(device, i2c);

	i2c->adap = mpc_ops;
	i2c_set_adapdata(&i2c->adap, i2c);
	i2c->adap.dev.parent = &pdev->dev;
	if ((result = i2c_add_adapter(&i2c->adap)) < 0) {
	printk(KERN_ERR "i2c-mpc - failed to add adapter\n");
	goto fail_add;
	}

	return result;

	fail_add:
	if (i2c->irq != 0)
	free_irq(i2c->irq, NULL);
	fail_irq:
	iounmap(i2c->base);
	fail_map:
	kfree(i2c);
	return result;
	};

	static int fsl_i2c_remove(struct device *device)
	{
	struct mpc_i2c *i2c = dev_get_drvdata(device);

	i2c_del_adapter(&i2c->adap);
	dev_set_drvdata(device, NULL);

	if (i2c->irq != 0)
	free_irq(i2c->irq, i2c);

	iounmap(i2c->base);
	kfree(i2c);
	return 0;
	};

	/* Structure for a device driver */
	static struct device_driver fsl_i2c_driver = {
	.owner = THIS_MODULE,
	.name = "fsl-i2c",
	.bus = &platform_bus_type,
	.probe = fsl_i2c_probe,
	.remove = fsl_i2c_remove,
	};

	static int __init fsl_i2c_init(void)
	{
	return driver_register(&fsl_i2c_driver);
	}

	static void __exit fsl_i2c_exit(void)
	{
	driver_unregister(&fsl_i2c_driver);
	}

	module_init(fsl_i2c_init);
	module_exit(fsl_i2c_exit);

	MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
	MODULE_DESCRIPTION
	("I2C-Bus adapter for MPC107 bridge and MPC824x/85xx/52xx processors");
	MODULE_LICENSE("GPL");