drivers/watchdog/ls1024a_wdt.c - kernel/mindspeed - Git at Google

 /*
  *  drivers/watchdog/ls1024a_wdt.c
  *
  *  Copyright (C) 2004,2005,2013 Mindspeed Technologies, Inc.
  *
  * 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
  */

 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/platform_device.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
 #include <linux/clk.h>
 #include <linux/timer.h>
 #include <linux/io.h>
 #include <linux/regmap.h>
 #include <linux/mfd/syscon.h>
 #include <asm/bitops.h>
 #include <asm/uaccess.h>

 #define LS1024A_TIMER_WDT_HIGH_BOUND			0x0
 #define LS1024A_TIMER_WDT_CONTROL			0x4
 #define  LS1024A_TIMER_WDT_CONTROL_TIMER_ENABLE		BIT(0)
 #define LS1024A_TIMER_WDT_CURRENT_COUNT			0x8

 #define LS1024A_DEVICE_RST_CNTRL			0x0
 #define  LS1024A_WD_STATUS_CLR				BIT(6)
 #define  LS1024A_AXI_WD_RST_EN				BIT(5)
 #define LS1024A_GNRL_DEVICE_STATUS			0x18
 #define  LS1024A_AXI_WD_RST_ACTIVATED			BIT(0)

 #define WDT_NAME					"comcerto_wdt"

 /* these are the actual wdt limits */
 #define WDT_DEFAULT_TIMEOUT				5
 #define WDT_MAX_TIMEOUT					(0xffffffff / LS1024A_AHBCLK)

 /* these are for the virtual wdt */
 #define WDT_DEFAULT_TIME				70	/* seconds */
 #define WDT_MAX_TIME					255	/* seconds */

 static unsigned long LS1024A_AHBCLK;
 static int wd_heartbeat = WDT_DEFAULT_TIMEOUT;
 static int wd_time = WDT_DEFAULT_TIME;
 static int nowayout = WATCHDOG_NOWAYOUT;
 static struct clk *axi_clk;
 static struct regmap *clk_rst_map;
 static void __iomem *ls1024a_wdt_base;

 module_param(wd_heartbeat, int, 0);
 MODULE_PARM_DESC(wd_heartbeat, "Watchdog heartbeat in seconds. (default="__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");

 module_param(wd_time, int, 0);
 MODULE_PARM_DESC(wd_time, "Watchdog time in seconds. (default="__MODULE_STRING(WDT_DEFAULT_TIME) ")");

 #ifdef CONFIG_WATCHDOG_NOWAYOUT
 module_param(nowayout, int, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 #endif

 static struct timer_list wdt_timer;

 static unsigned long ls1024a_wdt_busy;
 static char expect_close;
 static spinlock_t wdt_lock;
 static atomic_t ticks;

 /*
  * Inform whether the boot was caused by AXI watchdog or not.
  * If the boot was caused by AXI WDT, the WD status is cleared from
  * reset control register.
  */
 static int ls1024a_wdt_rst_status(void)
 {
 	unsigned long flags;
 	u32 val;
 	int ret = 0;

 	spin_lock_irqsave(&wdt_lock, flags);

 	regmap_read(clk_rst_map, LS1024A_GNRL_DEVICE_STATUS, &val);

 	if (val & LS1024A_AXI_WD_RST_ACTIVATED) {
 		regmap_update_bits(clk_rst_map, LS1024A_DEVICE_RST_CNTRL,
 				   LS1024A_WD_STATUS_CLR,
 				   LS1024A_WD_STATUS_CLR);
 		ret = 1;
 	}

 	spin_unlock_irqrestore(&wdt_lock, flags);

 	return ret;
 }

 /*
  * Set a new heartbeat value for the watchdog device. If the heartbeat value is
  * incorrect we keep the old value and return -EINVAL. If successfull we return 0.
  */
 static int ls1024a_wdt_set_heartbeat(int t)
 {
 	if (t < 1 || t > WDT_MAX_TIMEOUT)
 		return -EINVAL;

 	wd_heartbeat = t;
 	return 0;
 }

 /*
  * Write wd_heartbeat to high bound register.
  */
 static void ls1024a_wdt_pet_watchdog_physical(void)
 {
 	__raw_writel(wd_heartbeat * LS1024A_AHBCLK,
 		     ls1024a_wdt_base + LS1024A_TIMER_WDT_HIGH_BOUND);
 }

 /*
  * reset virtual wdt timer
  */
 static void ls1024a_wdt_pet_watchdog_virtual(void)
 {
 	atomic_set(&ticks, wd_time);
 }

 /*
  * set virtual wd timeout reset value
  */
 static int ls1024a_wdt_settimeout(int new_time)
 {
 	if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
 		return -EINVAL;

 	wd_time = new_time;
 	return 0;
 }

 /*
  * implement virtual wdt on physical wdt with timer
  */
 static void ls1024a_timer_tick(unsigned long unused)
 {
 	if (!atomic_dec_and_test(&ticks)) {
 		ls1024a_wdt_pet_watchdog_physical();
 		mod_timer(&wdt_timer, jiffies + HZ);
 	} else {
 		printk(KERN_CRIT "%s: Watchdog will fire soon!!!\n", WDT_NAME);
 	}
 }

 /*
  * Disable the watchdog.
  */
 static void ls1024a_wdt_stop(void)
 {
 	unsigned long flags;
 	u32 wdt_control;

 	spin_lock_irqsave(&wdt_lock, flags);

 	del_timer(&wdt_timer);

 	wdt_control = __raw_readl(ls1024a_wdt_base + LS1024A_TIMER_WDT_CONTROL);
 	wdt_control &= ~LS1024A_TIMER_WDT_CONTROL_TIMER_ENABLE;
 	__raw_writel(wdt_control, ls1024a_wdt_base + LS1024A_TIMER_WDT_CONTROL);

 	spin_unlock_irqrestore(&wdt_lock, flags);

 	ls1024a_wdt_pet_watchdog_physical();
 }

 /*
  * Enable the watchdog.
  */
 static void ls1024a_wdt_start(void)
 {
 	unsigned long flags;
 	u32 wdt_control;

 	spin_lock_irqsave(&wdt_lock, flags);

 	wdt_control = __raw_readl(ls1024a_wdt_base + LS1024A_TIMER_WDT_CONTROL);
 	wdt_control |= LS1024A_TIMER_WDT_CONTROL_TIMER_ENABLE;
 	__raw_writel(wdt_control, ls1024a_wdt_base + LS1024A_TIMER_WDT_CONTROL);

 	regmap_update_bits(clk_rst_map, LS1024A_DEVICE_RST_CNTRL,
 			   LS1024A_AXI_WD_RST_EN, LS1024A_AXI_WD_RST_EN);

 	mod_timer(&wdt_timer, jiffies + HZ);

 	spin_unlock_irqrestore(&wdt_lock, flags);
 }

 /*
  * Disable WDT and:
  * - set max. possible timeout to avoid reset, it can occur
  * since current counter value could be bigger then
  * high bound one at the moment
  * Function is called once at start (while configuration),
  * and it's safe not to disable/enable IRQs.
  */
 static void ls1024a_wdt_config(void)
 {
 	ls1024a_wdt_stop();

 	__raw_writel(~0, ls1024a_wdt_base + LS1024A_TIMER_WDT_HIGH_BOUND);	/* write max timeout */
 }

 /*
  * Watchdog device is opened, and watchdog starts running.
  */
 static int ls1024a_wdt_open(struct inode *inode, struct file *file)
 {
 	if (test_and_set_bit(0, &ls1024a_wdt_busy))
 		return -EBUSY;

 	ls1024a_wdt_pet_watchdog_virtual();
 	ls1024a_wdt_pet_watchdog_physical();
 	ls1024a_wdt_start();

 	return nonseekable_open(inode, file);
 }

 /*
  * Release the watchdog device.
  * If CONFIG_WATCHDOG_NOWAYOUT is NOT defined and expect_close == 42
  * i.e. magic char 'V' has been passed while write() then the watchdog
  * is also disabled.
  */
 static int ls1024a_wdt_release(struct inode *inode, struct file *file)
 {
 	if (expect_close == 42) {
 		ls1024a_wdt_stop();	/* disable the watchdog when file is closed */
 		clear_bit(0, &ls1024a_wdt_busy);
 	} else {
 		printk(KERN_CRIT "%s: closed unexpectedly. WDT will not stop!\n", WDT_NAME);
 	}

 	expect_close = 0;
 	return 0;
 }

 /*
  * Handle commands from user-space.
  */
 static long ls1024a_wdt_ioctl(struct file *file, uint cmd, ulong arg)
 {
 	void __user *argp = (void __user *)arg;
 	int __user *p = argp;
 	int new_value;
 	int err;
 	static struct watchdog_info ls1024a_wdt_info = {
 		.options = 	WDIOF_SETTIMEOUT |
 				WDIOF_MAGICCLOSE |
 				WDIOF_KEEPALIVEPING,
 		.firmware_version = 1,
 	};

 	switch(cmd) {
 	case WDIOC_KEEPALIVE:
 		ls1024a_wdt_pet_watchdog_virtual();
 		break;

 	case WDIOC_GETSUPPORT:
 		strncpy(ls1024a_wdt_info.identity, WDT_NAME, sizeof(ls1024a_wdt_info.identity));
 		if (copy_to_user(argp, &ls1024a_wdt_info, sizeof(ls1024a_wdt_info)) != 0) {
 			err = -EFAULT;
 			goto err;
 		}
 		break;

 	case WDIOC_SETTIMEOUT:
 		if (get_user(new_value, p)) {
 			err = -EFAULT;
 			goto err;
 		}

 		if (ls1024a_wdt_settimeout(new_value)) {
 			err = -EINVAL;
 			goto err;
 		}

 		ls1024a_wdt_pet_watchdog_virtual();

 		return put_user(wd_time, p);
 		break;

 	case WDIOC_GETTIMEOUT:
 		return put_user(wd_time, p);
 		break;

 	case WDIOC_GETSTATUS:
 		return put_user(0, p);
 		break;

 	case WDIOC_GETBOOTSTATUS:
 		return put_user(ls1024a_wdt_rst_status(), p);
 		break;

 	case WDIOC_SETOPTIONS:
 		if (get_user(new_value, p)) {
 			err = -EFAULT;
 			goto err;
 		}

 		if (new_value & WDIOS_DISABLECARD)
 			ls1024a_wdt_stop();

 		if (new_value & WDIOS_ENABLECARD)
 			ls1024a_wdt_start();

 		break;

 	default:
 		err = -ENOIOCTLCMD;
 		goto err;
 		break;
 	}

 	return 0;

 err:
 	return err;
 }

 /*
  * Pat the watchdog whenever device is written to.
  */
 static ssize_t ls1024a_wdt_write(struct file *file, const char *buf, size_t len, loff_t *ppos)
 {
 	if (len) {
 		if (!nowayout) {
 			size_t i;
 			char c;

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

 			for (i = 0; i != len; i++) {
 				if (get_user(c, buf + i))
 					return -EFAULT;

 				if (c == 'V')
 					expect_close = 42;
 			}
 		}

 		ls1024a_wdt_pet_watchdog_virtual();
 	}

 	return len;
 }

 static const struct file_operations ls1024a_wdt_fops = {
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
 	.unlocked_ioctl	= ls1024a_wdt_ioctl,
 	.open		= ls1024a_wdt_open,
 	.release	= ls1024a_wdt_release,
 	.write		= ls1024a_wdt_write,
 };

 static struct miscdevice ls1024a_wdt_miscdev = {
 	.minor		= WATCHDOG_MINOR,
 	.name		= WDT_NAME,
 	.fops		= &ls1024a_wdt_fops,
 };

 static int ls1024a_wdt_probe(struct platform_device *pdev)
 {
 	int res;
 	struct resource *iores_mem;
 	struct device *dev = &pdev->dev;

 	if (ls1024a_wdt_miscdev.parent)
 		return -EBUSY;

 	spin_lock_init(&wdt_lock);

 	axi_clk = devm_clk_get(dev, NULL);
 	if (IS_ERR(axi_clk)) {
 		dev_err(dev, "unable to obtain AXI clock: %ld\n", PTR_ERR(axi_clk));
 		return -ENODEV;
 	}

 	res = clk_prepare_enable(axi_clk);
 	if (res) {
 		dev_err(dev, "failed to enable AXI clock\n");
 		goto err_clk;
 	}

 	LS1024A_AHBCLK = clk_get_rate(axi_clk);

 	iores_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!iores_mem) {
 		dev_err(dev, "unable to obtain IORESOURCE_MEM\n");
 		goto err_mem;
 	}

 	ls1024a_wdt_base = devm_ioremap_resource(dev, iores_mem);
 	if (IS_ERR(ls1024a_wdt_base)) {
 		dev_err(dev, "devm_ioremap_resource failed: %ld\n", PTR_ERR(ls1024a_wdt_base));
 		goto err_mem;
 	}

 	clk_rst_map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");
 	if (IS_ERR(clk_rst_map)) {
 		dev_err(dev, "unable to obtain regmap: %ld\n", PTR_ERR(clk_rst_map));
 		goto err_misc;
 	}

 	setup_timer(&wdt_timer, ls1024a_timer_tick, 0L);

 	ls1024a_wdt_miscdev.parent = dev;
 	ls1024a_wdt_config();

 	res = misc_register(&ls1024a_wdt_miscdev);
 	if (res)
 		goto err_misc;

 	/* check that the heartbeat value is within range; if not reset to the default */
 	if (ls1024a_wdt_set_heartbeat(wd_heartbeat)) {
 		ls1024a_wdt_set_heartbeat(WDT_DEFAULT_TIMEOUT);

 		dev_err(dev, "wd_heartbeat value is out of range: 1..%lu, using %d\n",
 			WDT_MAX_TIMEOUT, WDT_DEFAULT_TIMEOUT);
 	}

 	/* check that the time value is within range; if not reset to the default */
 	if (ls1024a_wdt_settimeout(wd_time)) {
 		ls1024a_wdt_settimeout(WDT_DEFAULT_TIMEOUT);

 		dev_err(dev, "wd_time value is out of range: 1..%d, using %d\n",
 			WDT_MAX_TIME, WDT_DEFAULT_TIME);
 	}

 	return 0;

 err_misc:
 	devm_iounmap(dev, ls1024a_wdt_base);
 err_mem:
 	clk_disable_unprepare(axi_clk);
 err_clk:
 	devm_clk_put(dev, axi_clk);

 	return res;
 }

 static int ls1024a_wdt_remove(struct platform_device *pdev)
 {
 	int res;

 	res = misc_deregister(&ls1024a_wdt_miscdev);
 	if (!res)
 		ls1024a_wdt_miscdev.parent = NULL;

 	devm_iounmap(&pdev->dev, ls1024a_wdt_base);
 	clk_disable_unprepare(axi_clk);
 	devm_clk_put(&pdev->dev, axi_clk);

 	return res;
 }

 static const struct of_device_id ls1024a_wdt_of_match[] = {
 	{ .compatible = "fsl,ls1024a-wdt", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, ls1024a_wdt_of_match);

 static struct platform_driver ls1024a_wdt_driver = {
 	.driver	= {
 		.name = WDT_NAME,
 		.of_match_table = ls1024a_wdt_of_match,
 	},
 	.probe = ls1024a_wdt_probe,
 	.remove = ls1024a_wdt_remove,
 };

 module_platform_driver(ls1024a_wdt_driver);

 MODULE_AUTHOR("Mindspeed Technologies, Inc.");
 MODULE_DESCRIPTION("Watchdog driver for Freescale QorIQ LS1024A devices");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	/*
	* drivers/watchdog/ls1024a_wdt.c
	*
	* Copyright (C) 2004,2005,2013 Mindspeed Technologies, Inc.
	*
	* 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
	*/

	#include <linux/errno.h>
	#include <linux/fs.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/miscdevice.h>
	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/platform_device.h>
	#include <linux/types.h>
	#include <linux/watchdog.h>
	#include <linux/clk.h>
	#include <linux/timer.h>
	#include <linux/io.h>
	#include <linux/regmap.h>
	#include <linux/mfd/syscon.h>
	#include <asm/bitops.h>
	#include <asm/uaccess.h>

	#define LS1024A_TIMER_WDT_HIGH_BOUND 0x0
	#define LS1024A_TIMER_WDT_CONTROL 0x4
	#define LS1024A_TIMER_WDT_CONTROL_TIMER_ENABLE BIT(0)
	#define LS1024A_TIMER_WDT_CURRENT_COUNT 0x8

	#define LS1024A_DEVICE_RST_CNTRL 0x0
	#define LS1024A_WD_STATUS_CLR BIT(6)
	#define LS1024A_AXI_WD_RST_EN BIT(5)
	#define LS1024A_GNRL_DEVICE_STATUS 0x18
	#define LS1024A_AXI_WD_RST_ACTIVATED BIT(0)

	#define WDT_NAME "comcerto_wdt"

	/* these are the actual wdt limits */
	#define WDT_DEFAULT_TIMEOUT 5
	#define WDT_MAX_TIMEOUT (0xffffffff / LS1024A_AHBCLK)

	/* these are for the virtual wdt */
	#define WDT_DEFAULT_TIME 70 /* seconds */
	#define WDT_MAX_TIME 255 /* seconds */

	static unsigned long LS1024A_AHBCLK;
	static int wd_heartbeat = WDT_DEFAULT_TIMEOUT;
	static int wd_time = WDT_DEFAULT_TIME;
	static int nowayout = WATCHDOG_NOWAYOUT;
	static struct clk *axi_clk;
	static struct regmap *clk_rst_map;
	static void __iomem *ls1024a_wdt_base;

	module_param(wd_heartbeat, int, 0);
	MODULE_PARM_DESC(wd_heartbeat, "Watchdog heartbeat in seconds. (default="__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");

	module_param(wd_time, int, 0);
	MODULE_PARM_DESC(wd_time, "Watchdog time in seconds. (default="__MODULE_STRING(WDT_DEFAULT_TIME) ")");

	#ifdef CONFIG_WATCHDOG_NOWAYOUT
	module_param(nowayout, int, 0);
	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	#endif

	static struct timer_list wdt_timer;

	static unsigned long ls1024a_wdt_busy;
	static char expect_close;
	static spinlock_t wdt_lock;
	static atomic_t ticks;

	/*
	* Inform whether the boot was caused by AXI watchdog or not.
	* If the boot was caused by AXI WDT, the WD status is cleared from
	* reset control register.
	*/
	static int ls1024a_wdt_rst_status(void)
	{
	unsigned long flags;
	u32 val;
	int ret = 0;

	spin_lock_irqsave(&wdt_lock, flags);

	regmap_read(clk_rst_map, LS1024A_GNRL_DEVICE_STATUS, &val);

	if (val & LS1024A_AXI_WD_RST_ACTIVATED) {
	regmap_update_bits(clk_rst_map, LS1024A_DEVICE_RST_CNTRL,
	LS1024A_WD_STATUS_CLR,
	LS1024A_WD_STATUS_CLR);
	ret = 1;
	}

	spin_unlock_irqrestore(&wdt_lock, flags);

	return ret;
	}

	/*
	* Set a new heartbeat value for the watchdog device. If the heartbeat value is
	* incorrect we keep the old value and return -EINVAL. If successfull we return 0.
	*/
	static int ls1024a_wdt_set_heartbeat(int t)
	{
	if (t < 1 \|\| t > WDT_MAX_TIMEOUT)
	return -EINVAL;

	wd_heartbeat = t;
	return 0;
	}

	/*
	* Write wd_heartbeat to high bound register.
	*/
	static void ls1024a_wdt_pet_watchdog_physical(void)
	{
	__raw_writel(wd_heartbeat * LS1024A_AHBCLK,
	ls1024a_wdt_base + LS1024A_TIMER_WDT_HIGH_BOUND);
	}

	/*
	* reset virtual wdt timer
	*/
	static void ls1024a_wdt_pet_watchdog_virtual(void)
	{
	atomic_set(&ticks, wd_time);
	}

	/*
	* set virtual wd timeout reset value
	*/
	static int ls1024a_wdt_settimeout(int new_time)
	{
	if ((new_time <= 0) \|\| (new_time > WDT_MAX_TIME))
	return -EINVAL;

	wd_time = new_time;
	return 0;
	}

	/*
	* implement virtual wdt on physical wdt with timer
	*/
	static void ls1024a_timer_tick(unsigned long unused)
	{
	if (!atomic_dec_and_test(&ticks)) {
	ls1024a_wdt_pet_watchdog_physical();
	mod_timer(&wdt_timer, jiffies + HZ);
	} else {
	printk(KERN_CRIT "%s: Watchdog will fire soon!!!\n", WDT_NAME);
	}
	}

	/*
	* Disable the watchdog.
	*/
	static void ls1024a_wdt_stop(void)
	{
	unsigned long flags;
	u32 wdt_control;

	spin_lock_irqsave(&wdt_lock, flags);

	del_timer(&wdt_timer);

	wdt_control = __raw_readl(ls1024a_wdt_base + LS1024A_TIMER_WDT_CONTROL);
	wdt_control &= ~LS1024A_TIMER_WDT_CONTROL_TIMER_ENABLE;
	__raw_writel(wdt_control, ls1024a_wdt_base + LS1024A_TIMER_WDT_CONTROL);

	spin_unlock_irqrestore(&wdt_lock, flags);

	ls1024a_wdt_pet_watchdog_physical();
	}

	/*
	* Enable the watchdog.
	*/
	static void ls1024a_wdt_start(void)
	{
	unsigned long flags;
	u32 wdt_control;

	spin_lock_irqsave(&wdt_lock, flags);

	wdt_control = __raw_readl(ls1024a_wdt_base + LS1024A_TIMER_WDT_CONTROL);
	wdt_control \|= LS1024A_TIMER_WDT_CONTROL_TIMER_ENABLE;
	__raw_writel(wdt_control, ls1024a_wdt_base + LS1024A_TIMER_WDT_CONTROL);

	regmap_update_bits(clk_rst_map, LS1024A_DEVICE_RST_CNTRL,
	LS1024A_AXI_WD_RST_EN, LS1024A_AXI_WD_RST_EN);

	mod_timer(&wdt_timer, jiffies + HZ);

	spin_unlock_irqrestore(&wdt_lock, flags);
	}

	/*
	* Disable WDT and:
	* - set max. possible timeout to avoid reset, it can occur
	* since current counter value could be bigger then
	* high bound one at the moment
	* Function is called once at start (while configuration),
	* and it's safe not to disable/enable IRQs.
	*/
	static void ls1024a_wdt_config(void)
	{
	ls1024a_wdt_stop();

	__raw_writel(~0, ls1024a_wdt_base + LS1024A_TIMER_WDT_HIGH_BOUND); /* write max timeout */
	}

	/*
	* Watchdog device is opened, and watchdog starts running.
	*/
	static int ls1024a_wdt_open(struct inode inode, struct file file)
	{
	if (test_and_set_bit(0, &ls1024a_wdt_busy))
	return -EBUSY;

	ls1024a_wdt_pet_watchdog_virtual();
	ls1024a_wdt_pet_watchdog_physical();
	ls1024a_wdt_start();

	return nonseekable_open(inode, file);
	}

	/*
	* Release the watchdog device.
	* If CONFIG_WATCHDOG_NOWAYOUT is NOT defined and expect_close == 42
	* i.e. magic char 'V' has been passed while write() then the watchdog
	* is also disabled.
	*/
	static int ls1024a_wdt_release(struct inode inode, struct file file)
	{
	if (expect_close == 42) {
	ls1024a_wdt_stop(); /* disable the watchdog when file is closed */
	clear_bit(0, &ls1024a_wdt_busy);
	} else {
	printk(KERN_CRIT "%s: closed unexpectedly. WDT will not stop!\n", WDT_NAME);
	}

	expect_close = 0;
	return 0;
	}

	/*
	* Handle commands from user-space.
	*/
	static long ls1024a_wdt_ioctl(struct file *file, uint cmd, ulong arg)
	{
	void __user argp = (void __user )arg;
	int __user *p = argp;
	int new_value;
	int err;
	static struct watchdog_info ls1024a_wdt_info = {
	.options = WDIOF_SETTIMEOUT \|
	WDIOF_MAGICCLOSE \|
	WDIOF_KEEPALIVEPING,
	.firmware_version = 1,
	};

	switch(cmd) {
	case WDIOC_KEEPALIVE:
	ls1024a_wdt_pet_watchdog_virtual();
	break;

	case WDIOC_GETSUPPORT:
	strncpy(ls1024a_wdt_info.identity, WDT_NAME, sizeof(ls1024a_wdt_info.identity));
	if (copy_to_user(argp, &ls1024a_wdt_info, sizeof(ls1024a_wdt_info)) != 0) {
	err = -EFAULT;
	goto err;
	}
	break;

	case WDIOC_SETTIMEOUT:
	if (get_user(new_value, p)) {
	err = -EFAULT;
	goto err;
	}

	if (ls1024a_wdt_settimeout(new_value)) {
	err = -EINVAL;
	goto err;
	}

	ls1024a_wdt_pet_watchdog_virtual();

	return put_user(wd_time, p);
	break;

	case WDIOC_GETTIMEOUT:
	return put_user(wd_time, p);
	break;

	case WDIOC_GETSTATUS:
	return put_user(0, p);
	break;

	case WDIOC_GETBOOTSTATUS:
	return put_user(ls1024a_wdt_rst_status(), p);
	break;

	case WDIOC_SETOPTIONS:
	if (get_user(new_value, p)) {
	err = -EFAULT;
	goto err;
	}

	if (new_value & WDIOS_DISABLECARD)
	ls1024a_wdt_stop();

	if (new_value & WDIOS_ENABLECARD)
	ls1024a_wdt_start();

	break;

	default:
	err = -ENOIOCTLCMD;
	goto err;
	break;
	}

	return 0;

	err:
	return err;
	}

	/*
	* Pat the watchdog whenever device is written to.
	*/
	static ssize_t ls1024a_wdt_write(struct file file, const char buf, size_t len, loff_t *ppos)
	{
	if (len) {
	if (!nowayout) {
	size_t i;
	char c;

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

	for (i = 0; i != len; i++) {
	if (get_user(c, buf + i))
	return -EFAULT;

	if (c == 'V')
	expect_close = 42;
	}
	}

	ls1024a_wdt_pet_watchdog_virtual();
	}

	return len;
	}

	static const struct file_operations ls1024a_wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.unlocked_ioctl = ls1024a_wdt_ioctl,
	.open = ls1024a_wdt_open,
	.release = ls1024a_wdt_release,
	.write = ls1024a_wdt_write,
	};

	static struct miscdevice ls1024a_wdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = WDT_NAME,
	.fops = &ls1024a_wdt_fops,
	};

	static int ls1024a_wdt_probe(struct platform_device *pdev)
	{
	int res;
	struct resource *iores_mem;
	struct device *dev = &pdev->dev;

	if (ls1024a_wdt_miscdev.parent)
	return -EBUSY;

	spin_lock_init(&wdt_lock);

	axi_clk = devm_clk_get(dev, NULL);
	if (IS_ERR(axi_clk)) {
	dev_err(dev, "unable to obtain AXI clock: %ld\n", PTR_ERR(axi_clk));
	return -ENODEV;
	}

	res = clk_prepare_enable(axi_clk);
	if (res) {
	dev_err(dev, "failed to enable AXI clock\n");
	goto err_clk;
	}

	LS1024A_AHBCLK = clk_get_rate(axi_clk);

	iores_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!iores_mem) {
	dev_err(dev, "unable to obtain IORESOURCE_MEM\n");
	goto err_mem;
	}

	ls1024a_wdt_base = devm_ioremap_resource(dev, iores_mem);
	if (IS_ERR(ls1024a_wdt_base)) {
	dev_err(dev, "devm_ioremap_resource failed: %ld\n", PTR_ERR(ls1024a_wdt_base));
	goto err_mem;
	}

	clk_rst_map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");
	if (IS_ERR(clk_rst_map)) {
	dev_err(dev, "unable to obtain regmap: %ld\n", PTR_ERR(clk_rst_map));
	goto err_misc;
	}

	setup_timer(&wdt_timer, ls1024a_timer_tick, 0L);

	ls1024a_wdt_miscdev.parent = dev;
	ls1024a_wdt_config();

	res = misc_register(&ls1024a_wdt_miscdev);
	if (res)
	goto err_misc;

	/* check that the heartbeat value is within range; if not reset to the default */
	if (ls1024a_wdt_set_heartbeat(wd_heartbeat)) {
	ls1024a_wdt_set_heartbeat(WDT_DEFAULT_TIMEOUT);

	dev_err(dev, "wd_heartbeat value is out of range: 1..%lu, using %d\n",
	WDT_MAX_TIMEOUT, WDT_DEFAULT_TIMEOUT);
	}

	/* check that the time value is within range; if not reset to the default */
	if (ls1024a_wdt_settimeout(wd_time)) {
	ls1024a_wdt_settimeout(WDT_DEFAULT_TIMEOUT);

	dev_err(dev, "wd_time value is out of range: 1..%d, using %d\n",
	WDT_MAX_TIME, WDT_DEFAULT_TIME);
	}

	return 0;

	err_misc:
	devm_iounmap(dev, ls1024a_wdt_base);
	err_mem:
	clk_disable_unprepare(axi_clk);
	err_clk:
	devm_clk_put(dev, axi_clk);

	return res;
	}

	static int ls1024a_wdt_remove(struct platform_device *pdev)
	{
	int res;

	res = misc_deregister(&ls1024a_wdt_miscdev);
	if (!res)
	ls1024a_wdt_miscdev.parent = NULL;

	devm_iounmap(&pdev->dev, ls1024a_wdt_base);
	clk_disable_unprepare(axi_clk);
	devm_clk_put(&pdev->dev, axi_clk);

	return res;
	}

	static const struct of_device_id ls1024a_wdt_of_match[] = {
	{ .compatible = "fsl,ls1024a-wdt", },
	{},
	};
	MODULE_DEVICE_TABLE(of, ls1024a_wdt_of_match);

	static struct platform_driver ls1024a_wdt_driver = {
	.driver = {
	.name = WDT_NAME,
	.of_match_table = ls1024a_wdt_of_match,
	},
	.probe = ls1024a_wdt_probe,
	.remove = ls1024a_wdt_remove,
	};

	module_platform_driver(ls1024a_wdt_driver);

	MODULE_AUTHOR("Mindspeed Technologies, Inc.");
	MODULE_DESCRIPTION("Watchdog driver for Freescale QorIQ LS1024A devices");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);