drivers/watchdog/of_xilinx_wdt.c - maze/linux - Git at Google

 /*
  * Watchdog Device Driver for Xilinx axi/xps_timebase_wdt
  *
  * (C) Copyright 2011 (Alejandro Cabrera <aldaya@gmail.com>)
  *
  * 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.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/miscdevice.h>
 #include <linux/init.h>
 #include <linux/ioport.h>
 #include <linux/watchdog.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_address.h>

 /* Register offsets for the Wdt device */
 #define XWT_TWCSR0_OFFSET   0x0 /* Control/Status Register0 */
 #define XWT_TWCSR1_OFFSET   0x4 /* Control/Status Register1 */
 #define XWT_TBR_OFFSET      0x8 /* Timebase Register Offset */

 /* Control/Status Register Masks  */
 #define XWT_CSR0_WRS_MASK   0x00000008 /* Reset status */
 #define XWT_CSR0_WDS_MASK   0x00000004 /* Timer state  */
 #define XWT_CSR0_EWDT1_MASK 0x00000002 /* Enable bit 1 */

 /* Control/Status Register 0/1 bits  */
 #define XWT_CSRX_EWDT2_MASK 0x00000001 /* Enable bit 2 */

 /* SelfTest constants */
 #define XWT_MAX_SELFTEST_LOOP_COUNT 0x00010000
 #define XWT_TIMER_FAILED            0xFFFFFFFF

 #define WATCHDOG_NAME     "Xilinx Watchdog"
 #define PFX WATCHDOG_NAME ": "

 struct xwdt_device {
 	struct resource  res;
 	void __iomem *base;
 	u32 nowayout;
 	u32 wdt_interval;
 	u32 boot_status;
 };

 static struct xwdt_device xdev;

 static  u32 timeout;
 static  u32 control_status_reg;
 static  u8  expect_close;
 static  u8  no_timeout;
 static unsigned long driver_open;

 static  DEFINE_SPINLOCK(spinlock);

 static void xwdt_start(void)
 {
 	spin_lock(&spinlock);

 	/* Clean previous status and enable the watchdog timer */
 	control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);
 	control_status_reg |= (XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK);

 	iowrite32((control_status_reg | XWT_CSR0_EWDT1_MASK),
 				xdev.base + XWT_TWCSR0_OFFSET);

 	iowrite32(XWT_CSRX_EWDT2_MASK, xdev.base + XWT_TWCSR1_OFFSET);

 	spin_unlock(&spinlock);
 }

 static void xwdt_stop(void)
 {
 	spin_lock(&spinlock);

 	control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);

 	iowrite32((control_status_reg & ~XWT_CSR0_EWDT1_MASK),
 				xdev.base + XWT_TWCSR0_OFFSET);

 	iowrite32(0, xdev.base + XWT_TWCSR1_OFFSET);

 	spin_unlock(&spinlock);
 	pr_info("Stopped!\n");
 }

 static void xwdt_keepalive(void)
 {
 	spin_lock(&spinlock);

 	control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);
 	control_status_reg |= (XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK);
 	iowrite32(control_status_reg, xdev.base + XWT_TWCSR0_OFFSET);

 	spin_unlock(&spinlock);
 }

 static void xwdt_get_status(int *status)
 {
 	int new_status;

 	spin_lock(&spinlock);

 	control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);
 	new_status = ((control_status_reg &
 			(XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK)) != 0);
 	spin_unlock(&spinlock);

 	*status = 0;
 	if (new_status & 1)
 		*status |= WDIOF_CARDRESET;
 }

 static u32 xwdt_selftest(void)
 {
 	int i;
 	u32 timer_value1;
 	u32 timer_value2;

 	spin_lock(&spinlock);

 	timer_value1 = ioread32(xdev.base + XWT_TBR_OFFSET);
 	timer_value2 = ioread32(xdev.base + XWT_TBR_OFFSET);

 	for (i = 0;
 		((i <= XWT_MAX_SELFTEST_LOOP_COUNT) &&
 			(timer_value2 == timer_value1)); i++) {
 		timer_value2 = ioread32(xdev.base + XWT_TBR_OFFSET);
 	}

 	spin_unlock(&spinlock);

 	if (timer_value2 != timer_value1)
 		return ~XWT_TIMER_FAILED;
 	else
 		return XWT_TIMER_FAILED;
 }

 static int xwdt_open(struct inode *inode, struct file *file)
 {
 	/* Only one process can handle the wdt at a time */
 	if (test_and_set_bit(0, &driver_open))
 		return -EBUSY;

 	/* Make sure that the module are always loaded...*/
 	if (xdev.nowayout)
 		__module_get(THIS_MODULE);

 	xwdt_start();
 	pr_info("Started...\n");

 	return nonseekable_open(inode, file);
 }

 static int xwdt_release(struct inode *inode, struct file *file)
 {
 	if (expect_close == 42) {
 		xwdt_stop();
 	} else {
 		pr_crit("Unexpected close, not stopping watchdog!\n");
 		xwdt_keepalive();
 	}

 	clear_bit(0, &driver_open);
 	expect_close = 0;
 	return 0;
 }

 /*
  *      xwdt_write:
  *      @file: file handle to the watchdog
  *      @buf: buffer to write (unused as data does not matter here
  *      @count: count of bytes
  *      @ppos: pointer to the position to write. No seeks allowed
  *
  *      A write to a watchdog device is defined as a keepalive signal. Any
  *      write of data will do, as we don't define content meaning.
  */
 static ssize_t xwdt_write(struct file *file, const char __user *buf,
 						size_t len, loff_t *ppos)
 {
 	if (len) {
 		if (!xdev.nowayout) {
 			size_t i;

 			/* In case it was set long ago */
 			expect_close = 0;

 			for (i = 0; i != len; i++) {
 				char c;

 				if (get_user(c, buf + i))
 					return -EFAULT;
 				if (c == 'V')
 					expect_close = 42;
 			}
 		}
 		xwdt_keepalive();
 	}
 	return len;
 }

 static const struct watchdog_info ident = {
 	.options =  WDIOF_MAGICCLOSE |
 		    WDIOF_KEEPALIVEPING,
 	.firmware_version =	1,
 	.identity =	WATCHDOG_NAME,
 };

 /*
  *      xwdt_ioctl:
  *      @file: file handle to the device
  *      @cmd: watchdog command
  *      @arg: argument pointer
  *
  *      The watchdog API defines a common set of functions for all watchdogs
  *      according to their available features.
  */
 static long xwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	int status;

 	union {
 		struct watchdog_info __user *ident;
 		int __user *i;
 	} uarg;

 	uarg.i = (int __user *)arg;

 	switch (cmd) {
 	case WDIOC_GETSUPPORT:
 		return copy_to_user(uarg.ident, &ident,
 					sizeof(ident)) ? -EFAULT : 0;

 	case WDIOC_GETBOOTSTATUS:
 		return put_user(xdev.boot_status, uarg.i);

 	case WDIOC_GETSTATUS:
 		xwdt_get_status(&status);
 		return put_user(status, uarg.i);

 	case WDIOC_KEEPALIVE:
 		xwdt_keepalive();
 		return 0;

 	case WDIOC_GETTIMEOUT:
 		if (no_timeout)
 			return -ENOTTY;
 		else
 			return put_user(timeout, uarg.i);

 	default:
 		return -ENOTTY;
 	}
 }

 static const struct file_operations xwdt_fops = {
 	.owner      = THIS_MODULE,
 	.llseek     = no_llseek,
 	.write      = xwdt_write,
 	.open       = xwdt_open,
 	.release    = xwdt_release,
 	.unlocked_ioctl = xwdt_ioctl,
 };

 static struct miscdevice xwdt_miscdev = {
 	.minor      = WATCHDOG_MINOR,
 	.name       = "watchdog",
 	.fops       = &xwdt_fops,
 };

 static int xwdt_probe(struct platform_device *pdev)
 {
 	int rc;
 	u32 *tmptr;
 	u32 *pfreq;

 	no_timeout = 0;

 	pfreq = (u32 *)of_get_property(pdev->dev.of_node,
 					"clock-frequency", NULL);

 	if (pfreq == NULL) {
 		pr_warn("The watchdog clock frequency cannot be obtained!\n");
 		no_timeout = 1;
 	}

 	rc = of_address_to_resource(pdev->dev.of_node, 0, &xdev.res);
 	if (rc) {
 		pr_warn("invalid address!\n");
 		return rc;
 	}

 	tmptr = (u32 *)of_get_property(pdev->dev.of_node,
 					"xlnx,wdt-interval", NULL);
 	if (tmptr == NULL) {
 		pr_warn("Parameter \"xlnx,wdt-interval\" not found in device tree!\n");
 		no_timeout = 1;
 	} else {
 		xdev.wdt_interval = *tmptr;
 	}

 	tmptr = (u32 *)of_get_property(pdev->dev.of_node,
 					"xlnx,wdt-enable-once", NULL);
 	if (tmptr == NULL) {
 		pr_warn("Parameter \"xlnx,wdt-enable-once\" not found in device tree!\n");
 		xdev.nowayout = WATCHDOG_NOWAYOUT;
 	}

 /*
  *  Twice of the 2^wdt_interval / freq  because the first wdt overflow is
  *  ignored (interrupt), reset is only generated at second wdt overflow
  */
 	if (!no_timeout)
 		timeout = 2 * ((1<<xdev.wdt_interval) / *pfreq);

 	if (!request_mem_region(xdev.res.start,
 			xdev.res.end - xdev.res.start + 1, WATCHDOG_NAME)) {
 		rc = -ENXIO;
 		pr_err("memory request failure!\n");
 		goto err_out;
 	}

 	xdev.base = ioremap(xdev.res.start, xdev.res.end - xdev.res.start + 1);
 	if (xdev.base == NULL) {
 		rc = -ENOMEM;
 		pr_err("ioremap failure!\n");
 		goto release_mem;
 	}

 	rc = xwdt_selftest();
 	if (rc == XWT_TIMER_FAILED) {
 		pr_err("SelfTest routine error!\n");
 		goto unmap_io;
 	}

 	xwdt_get_status(&xdev.boot_status);

 	rc = misc_register(&xwdt_miscdev);
 	if (rc) {
 		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 		       xwdt_miscdev.minor, rc);
 		goto unmap_io;
 	}

 	if (no_timeout)
 		pr_info("driver loaded (timeout=? sec, nowayout=%d)\n",
 			xdev.nowayout);
 	else
 		pr_info("driver loaded (timeout=%d sec, nowayout=%d)\n",
 			timeout, xdev.nowayout);

 	expect_close = 0;
 	clear_bit(0, &driver_open);

 	return 0;

 unmap_io:
 	iounmap(xdev.base);
 release_mem:
 	release_mem_region(xdev.res.start, resource_size(&xdev.res));
 err_out:
 	return rc;
 }

 static int xwdt_remove(struct platform_device *dev)
 {
 	misc_deregister(&xwdt_miscdev);
 	iounmap(xdev.base);
 	release_mem_region(xdev.res.start, resource_size(&xdev.res));

 	return 0;
 }

 /* Match table for of_platform binding */
 static struct of_device_id xwdt_of_match[] = {
 	{ .compatible = "xlnx,xps-timebase-wdt-1.00.a", },
 	{ .compatible = "xlnx,xps-timebase-wdt-1.01.a", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, xwdt_of_match);

 static struct platform_driver xwdt_driver = {
 	.probe       = xwdt_probe,
 	.remove      = xwdt_remove,
 	.driver = {
 		.owner = THIS_MODULE,
 		.name  = WATCHDOG_NAME,
 		.of_match_table = xwdt_of_match,
 	},
 };

 module_platform_driver(xwdt_driver);

 MODULE_AUTHOR("Alejandro Cabrera <aldaya@gmail.com>");
 MODULE_DESCRIPTION("Xilinx Watchdog driver");
 MODULE_LICENSE("GPL v2");
	/*
	* Watchdog Device Driver for Xilinx axi/xps_timebase_wdt
	*
	* (C) Copyright 2011 (Alejandro Cabrera <aldaya@gmail.com>)
	*
	* 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.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/fs.h>
	#include <linux/miscdevice.h>
	#include <linux/init.h>
	#include <linux/ioport.h>
	#include <linux/watchdog.h>
	#include <linux/io.h>
	#include <linux/uaccess.h>
	#include <linux/of.h>
	#include <linux/of_device.h>
	#include <linux/of_address.h>

	/* Register offsets for the Wdt device */
	#define XWT_TWCSR0_OFFSET 0x0 /* Control/Status Register0 */
	#define XWT_TWCSR1_OFFSET 0x4 /* Control/Status Register1 */
	#define XWT_TBR_OFFSET 0x8 /* Timebase Register Offset */

	/* Control/Status Register Masks */
	#define XWT_CSR0_WRS_MASK 0x00000008 /* Reset status */
	#define XWT_CSR0_WDS_MASK 0x00000004 /* Timer state */
	#define XWT_CSR0_EWDT1_MASK 0x00000002 /* Enable bit 1 */

	/* Control/Status Register 0/1 bits */
	#define XWT_CSRX_EWDT2_MASK 0x00000001 /* Enable bit 2 */

	/* SelfTest constants */
	#define XWT_MAX_SELFTEST_LOOP_COUNT 0x00010000
	#define XWT_TIMER_FAILED 0xFFFFFFFF

	#define WATCHDOG_NAME "Xilinx Watchdog"
	#define PFX WATCHDOG_NAME ": "

	struct xwdt_device {
	struct resource res;
	void __iomem *base;
	u32 nowayout;
	u32 wdt_interval;
	u32 boot_status;
	};

	static struct xwdt_device xdev;

	static u32 timeout;
	static u32 control_status_reg;
	static u8 expect_close;
	static u8 no_timeout;
	static unsigned long driver_open;

	static DEFINE_SPINLOCK(spinlock);

	static void xwdt_start(void)
	{
	spin_lock(&spinlock);

	/* Clean previous status and enable the watchdog timer */
	control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);
	control_status_reg \|= (XWT_CSR0_WRS_MASK \| XWT_CSR0_WDS_MASK);

	iowrite32((control_status_reg \| XWT_CSR0_EWDT1_MASK),
	xdev.base + XWT_TWCSR0_OFFSET);

	iowrite32(XWT_CSRX_EWDT2_MASK, xdev.base + XWT_TWCSR1_OFFSET);

	spin_unlock(&spinlock);
	}

	static void xwdt_stop(void)
	{
	spin_lock(&spinlock);

	control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);

	iowrite32((control_status_reg & ~XWT_CSR0_EWDT1_MASK),
	xdev.base + XWT_TWCSR0_OFFSET);

	iowrite32(0, xdev.base + XWT_TWCSR1_OFFSET);

	spin_unlock(&spinlock);
	pr_info("Stopped!\n");
	}

	static void xwdt_keepalive(void)
	{
	spin_lock(&spinlock);

	control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);
	control_status_reg \|= (XWT_CSR0_WRS_MASK \| XWT_CSR0_WDS_MASK);
	iowrite32(control_status_reg, xdev.base + XWT_TWCSR0_OFFSET);

	spin_unlock(&spinlock);
	}

	static void xwdt_get_status(int *status)
	{
	int new_status;

	spin_lock(&spinlock);

	control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);
	new_status = ((control_status_reg &
	(XWT_CSR0_WRS_MASK \| XWT_CSR0_WDS_MASK)) != 0);
	spin_unlock(&spinlock);

	*status = 0;
	if (new_status & 1)
	*status \|= WDIOF_CARDRESET;
	}

	static u32 xwdt_selftest(void)
	{
	int i;
	u32 timer_value1;
	u32 timer_value2;

	spin_lock(&spinlock);

	timer_value1 = ioread32(xdev.base + XWT_TBR_OFFSET);
	timer_value2 = ioread32(xdev.base + XWT_TBR_OFFSET);

	for (i = 0;
	((i <= XWT_MAX_SELFTEST_LOOP_COUNT) &&
	(timer_value2 == timer_value1)); i++) {
	timer_value2 = ioread32(xdev.base + XWT_TBR_OFFSET);
	}

	spin_unlock(&spinlock);

	if (timer_value2 != timer_value1)
	return ~XWT_TIMER_FAILED;
	else
	return XWT_TIMER_FAILED;
	}

	static int xwdt_open(struct inode inode, struct file file)
	{
	/* Only one process can handle the wdt at a time */
	if (test_and_set_bit(0, &driver_open))
	return -EBUSY;

	/* Make sure that the module are always loaded...*/
	if (xdev.nowayout)
	__module_get(THIS_MODULE);

	xwdt_start();
	pr_info("Started...\n");

	return nonseekable_open(inode, file);
	}

	static int xwdt_release(struct inode inode, struct file file)
	{
	if (expect_close == 42) {
	xwdt_stop();
	} else {
	pr_crit("Unexpected close, not stopping watchdog!\n");
	xwdt_keepalive();
	}

	clear_bit(0, &driver_open);
	expect_close = 0;
	return 0;
	}

	/*
	* xwdt_write:
	* @file: file handle to the watchdog
	* @buf: buffer to write (unused as data does not matter here
	* @count: count of bytes
	* @ppos: pointer to the position to write. No seeks allowed
	*
	* A write to a watchdog device is defined as a keepalive signal. Any
	* write of data will do, as we don't define content meaning.
	*/
	static ssize_t xwdt_write(struct file file, const char __user buf,
	size_t len, loff_t *ppos)
	{
	if (len) {
	if (!xdev.nowayout) {
	size_t i;

	/* In case it was set long ago */
	expect_close = 0;

	for (i = 0; i != len; i++) {
	char c;

	if (get_user(c, buf + i))
	return -EFAULT;
	if (c == 'V')
	expect_close = 42;
	}
	}
	xwdt_keepalive();
	}
	return len;
	}

	static const struct watchdog_info ident = {
	.options = WDIOF_MAGICCLOSE \|
	WDIOF_KEEPALIVEPING,
	.firmware_version = 1,
	.identity = WATCHDOG_NAME,
	};

	/*
	* xwdt_ioctl:
	* @file: file handle to the device
	* @cmd: watchdog command
	* @arg: argument pointer
	*
	* The watchdog API defines a common set of functions for all watchdogs
	* according to their available features.
	*/
	static long xwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	{
	int status;

	union {
	struct watchdog_info __user *ident;
	int __user *i;
	} uarg;

	uarg.i = (int __user *)arg;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
	return copy_to_user(uarg.ident, &ident,
	sizeof(ident)) ? -EFAULT : 0;

	case WDIOC_GETBOOTSTATUS:
	return put_user(xdev.boot_status, uarg.i);

	case WDIOC_GETSTATUS:
	xwdt_get_status(&status);
	return put_user(status, uarg.i);

	case WDIOC_KEEPALIVE:
	xwdt_keepalive();
	return 0;

	case WDIOC_GETTIMEOUT:
	if (no_timeout)
	return -ENOTTY;
	else
	return put_user(timeout, uarg.i);

	default:
	return -ENOTTY;
	}
	}

	static const struct file_operations xwdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = xwdt_write,
	.open = xwdt_open,
	.release = xwdt_release,
	.unlocked_ioctl = xwdt_ioctl,
	};

	static struct miscdevice xwdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &xwdt_fops,
	};

	static int xwdt_probe(struct platform_device *pdev)
	{
	int rc;
	u32 *tmptr;
	u32 *pfreq;

	no_timeout = 0;

	pfreq = (u32 *)of_get_property(pdev->dev.of_node,
	"clock-frequency", NULL);

	if (pfreq == NULL) {
	pr_warn("The watchdog clock frequency cannot be obtained!\n");
	no_timeout = 1;
	}

	rc = of_address_to_resource(pdev->dev.of_node, 0, &xdev.res);
	if (rc) {
	pr_warn("invalid address!\n");
	return rc;
	}

	tmptr = (u32 *)of_get_property(pdev->dev.of_node,
	"xlnx,wdt-interval", NULL);
	if (tmptr == NULL) {
	pr_warn("Parameter \"xlnx,wdt-interval\" not found in device tree!\n");
	no_timeout = 1;
	} else {
	xdev.wdt_interval = *tmptr;
	}

	tmptr = (u32 *)of_get_property(pdev->dev.of_node,
	"xlnx,wdt-enable-once", NULL);
	if (tmptr == NULL) {
	pr_warn("Parameter \"xlnx,wdt-enable-once\" not found in device tree!\n");
	xdev.nowayout = WATCHDOG_NOWAYOUT;
	}

	/*
	* Twice of the 2^wdt_interval / freq because the first wdt overflow is
	* ignored (interrupt), reset is only generated at second wdt overflow
	*/
	if (!no_timeout)
	timeout = 2 * ((1<<xdev.wdt_interval) / *pfreq);

	if (!request_mem_region(xdev.res.start,
	xdev.res.end - xdev.res.start + 1, WATCHDOG_NAME)) {
	rc = -ENXIO;
	pr_err("memory request failure!\n");
	goto err_out;
	}

	xdev.base = ioremap(xdev.res.start, xdev.res.end - xdev.res.start + 1);
	if (xdev.base == NULL) {
	rc = -ENOMEM;
	pr_err("ioremap failure!\n");
	goto release_mem;
	}

	rc = xwdt_selftest();
	if (rc == XWT_TIMER_FAILED) {
	pr_err("SelfTest routine error!\n");
	goto unmap_io;
	}

	xwdt_get_status(&xdev.boot_status);

	rc = misc_register(&xwdt_miscdev);
	if (rc) {
	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
	xwdt_miscdev.minor, rc);
	goto unmap_io;
	}

	if (no_timeout)
	pr_info("driver loaded (timeout=? sec, nowayout=%d)\n",
	xdev.nowayout);
	else
	pr_info("driver loaded (timeout=%d sec, nowayout=%d)\n",
	timeout, xdev.nowayout);

	expect_close = 0;
	clear_bit(0, &driver_open);

	return 0;

	unmap_io:
	iounmap(xdev.base);
	release_mem:
	release_mem_region(xdev.res.start, resource_size(&xdev.res));
	err_out:
	return rc;
	}

	static int xwdt_remove(struct platform_device *dev)
	{
	misc_deregister(&xwdt_miscdev);
	iounmap(xdev.base);
	release_mem_region(xdev.res.start, resource_size(&xdev.res));

	return 0;
	}

	/* Match table for of_platform binding */
	static struct of_device_id xwdt_of_match[] = {
	{ .compatible = "xlnx,xps-timebase-wdt-1.00.a", },
	{ .compatible = "xlnx,xps-timebase-wdt-1.01.a", },
	{},
	};
	MODULE_DEVICE_TABLE(of, xwdt_of_match);

	static struct platform_driver xwdt_driver = {
	.probe = xwdt_probe,
	.remove = xwdt_remove,
	.driver = {
	.owner = THIS_MODULE,
	.name = WATCHDOG_NAME,
	.of_match_table = xwdt_of_match,
	},
	};

	module_platform_driver(xwdt_driver);

	MODULE_AUTHOR("Alejandro Cabrera <aldaya@gmail.com>");
	MODULE_DESCRIPTION("Xilinx Watchdog driver");
	MODULE_LICENSE("GPL v2");