[net-next-2.6.git] / drivers / watchdog / ks8695_wdt.c

/*
 * Watchdog driver for Kendin/Micrel KS8695.
 *
 * (C) 2007 Andrew Victor
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/bitops.h>
#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/io.h>
#include <linux/uaccess.h>
#include <mach/timex.h>
#include <mach/regs-timer.h>

#define WDT_DEFAULT_TIME	5	/* seconds */
#define WDT_MAX_TIME		171	/* seconds */

static int wdt_time = WDT_DEFAULT_TIME;
static int nowayout = WATCHDOG_NOWAYOUT;

module_param(wdt_time, int, 0);
MODULE_PARM_DESC(wdt_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 unsigned long ks8695wdt_busy;
static spinlock_t ks8695_lock;

/* ......................................................................... */

/*
 * Disable the watchdog.
 */
static inline void ks8695_wdt_stop(void)
{
	unsigned long tmcon;

	spin_lock(&ks8695_lock);
	/* disable timer0 */
	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
	__raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
	spin_unlock(&ks8695_lock);
}

/*
 * Enable and reset the watchdog.
 */
static inline void ks8695_wdt_start(void)
{
	unsigned long tmcon;
	unsigned long tval = wdt_time * KS8695_CLOCK_RATE;

	spin_lock(&ks8695_lock);
	/* disable timer0 */
	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
	__raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);

	/* program timer0 */
	__raw_writel(tval | T0TC_WATCHDOG, KS8695_TMR_VA + KS8695_T0TC);

	/* re-enable timer0 */
	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
	__raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
	spin_unlock(&ks8695_lock);
}

/*
 * Reload the watchdog timer.  (ie, pat the watchdog)
 */
static inline void ks8695_wdt_reload(void)
{
	unsigned long tmcon;

	spin_lock(&ks8695_lock);
	/* disable, then re-enable timer0 */
	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
	__raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
	__raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
	spin_unlock(&ks8695_lock);
}

/*
 * Change the watchdog time interval.
 */
static int ks8695_wdt_settimeout(int new_time)
{
	/*
	 * All counting occurs at KS8695_CLOCK_RATE / 128 = 0.256 Hz
	 *
	 * Since WDV is a 16-bit counter, the maximum period is
	 * 65536 / 0.256 = 256 seconds.
	 */
	if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
		return -EINVAL;

	/* Set new watchdog time. It will be used when
	   ks8695_wdt_start() is called. */
	wdt_time = new_time;
	return 0;
}

/* ......................................................................... */

/*
 * Watchdog device is opened, and watchdog starts running.
 */
static int ks8695_wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &ks8695wdt_busy))
		return -EBUSY;

	ks8695_wdt_start();
	return nonseekable_open(inode, file);
}

/*
 * Close the watchdog device.
 * If CONFIG_WATCHDOG_NOWAYOUT is NOT defined then the watchdog is also
 *  disabled.
 */
static int ks8695_wdt_close(struct inode *inode, struct file *file)
{
	/* Disable the watchdog when file is closed */
	if (!nowayout)
		ks8695_wdt_stop();
	clear_bit(0, &ks8695wdt_busy);
	return 0;
}

static const struct watchdog_info ks8695_wdt_info = {
	.identity	= "ks8695 watchdog",
	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
};

/*
 * Handle commands from user-space.
 */
static long ks8695_wdt_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int new_value;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(argp, &ks8695_wdt_info,
					sizeof(ks8695_wdt_info)) ? -EFAULT : 0;
	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);
	case WDIOC_SETOPTIONS:
		if (get_user(new_value, p))
			return -EFAULT;
		if (new_value & WDIOS_DISABLECARD)
			ks8695_wdt_stop();
		if (new_value & WDIOS_ENABLECARD)
			ks8695_wdt_start();
		return 0;
	case WDIOC_KEEPALIVE:
		ks8695_wdt_reload();	/* pat the watchdog */
		return 0;
	case WDIOC_SETTIMEOUT:
		if (get_user(new_value, p))
			return -EFAULT;
		if (ks8695_wdt_settimeout(new_value))
			return -EINVAL;
		/* Enable new time value */
		ks8695_wdt_start();
		/* Return current value */
		return put_user(wdt_time, p);
	case WDIOC_GETTIMEOUT:
		return put_user(wdt_time, p);
	default:
		return -ENOTTY;
	}
}

/*
 * Pat the watchdog whenever device is written to.
 */
static ssize_t ks8695_wdt_write(struct file *file, const char *data,
						size_t len, loff_t *ppos)
{
	ks8695_wdt_reload();		/* pat the watchdog */
	return len;
}

/* ......................................................................... */

static const struct file_operations ks8695wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.unlocked_ioctl	= ks8695_wdt_ioctl,
	.open		= ks8695_wdt_open,
	.release	= ks8695_wdt_close,
	.write		= ks8695_wdt_write,
};

static struct miscdevice ks8695wdt_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &ks8695wdt_fops,
};

static int __devinit ks8695wdt_probe(struct platform_device *pdev)
{
	int res;

	if (ks8695wdt_miscdev.parent)
		return -EBUSY;
	ks8695wdt_miscdev.parent = &pdev->dev;

	res = misc_register(&ks8695wdt_miscdev);
	if (res)
		return res;

	printk(KERN_INFO "KS8695 Watchdog Timer enabled (%d seconds%s)\n",
				wdt_time, nowayout ? ", nowayout" : "");
	return 0;
}

static int __devexit ks8695wdt_remove(struct platform_device *pdev)
{
	int res;

	res = misc_deregister(&ks8695wdt_miscdev);
	if (!res)
		ks8695wdt_miscdev.parent = NULL;

	return res;
}

static void ks8695wdt_shutdown(struct platform_device *pdev)
{
	ks8695_wdt_stop();
}

#ifdef CONFIG_PM

static int ks8695wdt_suspend(struct platform_device *pdev, pm_message_t message)
{
	ks8695_wdt_stop();
	return 0;
}

static int ks8695wdt_resume(struct platform_device *pdev)
{
	if (ks8695wdt_busy)
		ks8695_wdt_start();
	return 0;
}

#else
#define ks8695wdt_suspend NULL
#define ks8695wdt_resume	NULL
#endif

static struct platform_driver ks8695wdt_driver = {
	.probe		= ks8695wdt_probe,
	.remove		= __devexit_p(ks8695wdt_remove),
	.shutdown	= ks8695wdt_shutdown,
	.suspend	= ks8695wdt_suspend,
	.resume		= ks8695wdt_resume,
	.driver		= {
		.name	= "ks8695_wdt",
		.owner	= THIS_MODULE,
	},
};

static int __init ks8695_wdt_init(void)
{
	spin_lock_init(&ks8695_lock);
	/* Check that the heartbeat value is within range;
	   if not reset to the default */
	if (ks8695_wdt_settimeout(wdt_time)) {
		ks8695_wdt_settimeout(WDT_DEFAULT_TIME);
		pr_info("ks8695_wdt: wdt_time value must be 1 <= wdt_time <= %i"
					", using %d\n", wdt_time, WDT_MAX_TIME);
	}
	return platform_driver_register(&ks8695wdt_driver);
}

static void __exit ks8695_wdt_exit(void)
{
	platform_driver_unregister(&ks8695wdt_driver);
}

module_init(ks8695_wdt_init);
module_exit(ks8695_wdt_exit);

MODULE_AUTHOR("Andrew Victor");
MODULE_DESCRIPTION("Watchdog driver for KS8695");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS("platform:ks8695_wdt");
Commit	Line	Data
ccb8f430 AV	1	/*
	2	* Watchdog driver for Kendin/Micrel KS8695.
	3	*
	4	* (C) 2007 Andrew Victor
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10
1977f032	11	#include <linux/bitops.h>
ccb8f430 AV	12	#include <linux/errno.h>
	13	#include <linux/fs.h>
	14	#include <linux/init.h>
	15	#include <linux/kernel.h>
	16	#include <linux/miscdevice.h>
	17	#include <linux/module.h>
	18	#include <linux/moduleparam.h>
	19	#include <linux/platform_device.h>
	20	#include <linux/types.h>
	21	#include <linux/watchdog.h>
f4fabce1 AC	22	#include <linux/io.h>
f4fabce1 AC	23	#include <linux/uaccess.h>
b02c3878	24	#include <mach/timex.h>
a09e64fb	25	#include <mach/regs-timer.h>
ccb8f430	26
ccb8f430 AV	27	#define WDT_DEFAULT_TIME 5 /* seconds */
	28	#define WDT_MAX_TIME 171 /* seconds */
	29
	30	static int wdt_time = WDT_DEFAULT_TIME;
	31	static int nowayout = WATCHDOG_NOWAYOUT;
	32
	33	module_param(wdt_time, int, 0);
f4fabce1 AC	34	MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
f4fabce1 AC	35	__MODULE_STRING(WDT_DEFAULT_TIME) ")");
ccb8f430 AV	36
	37	#ifdef CONFIG_WATCHDOG_NOWAYOUT
	38	module_param(nowayout, int, 0);
f4fabce1 AC	39	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
f4fabce1 AC	40	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
ccb8f430 AV	41	#endif
	42
	43
	44	static unsigned long ks8695wdt_busy;
f4fabce1	45	static spinlock_t ks8695_lock;
ccb8f430 AV	46
	47	/* ......................................................................... */
	48
	49	/*
	50	* Disable the watchdog.
	51	*/
f4fabce1	52	static inline void ks8695_wdt_stop(void)
ccb8f430 AV	53	{
	54	unsigned long tmcon;
	55
f4fabce1	56	spin_lock(&ks8695_lock);
ccb8f430 AV	57	/* disable timer0 */
	58	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
	59	__raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
f4fabce1	60	spin_unlock(&ks8695_lock);
ccb8f430 AV	61	}
	62
	63	/*
	64	* Enable and reset the watchdog.
	65	*/
f4fabce1	66	static inline void ks8695_wdt_start(void)
ccb8f430 AV	67	{
ccb8f430 AV	68	unsigned long tmcon;
0a51810a	69	unsigned long tval = wdt_time * KS8695_CLOCK_RATE;
ccb8f430	70
f4fabce1	71	spin_lock(&ks8695_lock);
ccb8f430 AV	72	/* disable timer0 */
	73	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
	74	__raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
	75
	76	/* program timer0 */
	77	__raw_writel(tval \| T0TC_WATCHDOG, KS8695_TMR_VA + KS8695_T0TC);
	78
	79	/* re-enable timer0 */
	80	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
	81	__raw_writel(tmcon \| TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
f4fabce1	82	spin_unlock(&ks8695_lock);
ccb8f430 AV	83	}
	84
	85	/*
	86	* Reload the watchdog timer. (ie, pat the watchdog)
	87	*/
f4fabce1	88	static inline void ks8695_wdt_reload(void)
ccb8f430 AV	89	{
	90	unsigned long tmcon;
	91
f4fabce1	92	spin_lock(&ks8695_lock);
ccb8f430 AV	93	/* disable, then re-enable timer0 */
	94	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);
	95	__raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
	96	__raw_writel(tmcon \| TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);
f4fabce1	97	spin_unlock(&ks8695_lock);
ccb8f430 AV	98	}
	99
	100	/*
	101	* Change the watchdog time interval.
	102	*/
	103	static int ks8695_wdt_settimeout(int new_time)
	104	{
	105	/*
0a51810a	106	* All counting occurs at KS8695_CLOCK_RATE / 128 = 0.256 Hz
ccb8f430 AV	107	*
	108	* Since WDV is a 16-bit counter, the maximum period is
	109	* 65536 / 0.256 = 256 seconds.
	110	*/
	111	if ((new_time <= 0) \|\| (new_time > WDT_MAX_TIME))
	112	return -EINVAL;
	113
f4fabce1 AC	114	/* Set new watchdog time. It will be used when
f4fabce1 AC	115	ks8695_wdt_start() is called. */
ccb8f430 AV	116	wdt_time = new_time;
	117	return 0;
	118	}
	119
	120	/* ......................................................................... */
	121
	122	/*
	123	* Watchdog device is opened, and watchdog starts running.
	124	*/
	125	static int ks8695_wdt_open(struct inode inode, struct file file)
	126	{
	127	if (test_and_set_bit(0, &ks8695wdt_busy))
	128	return -EBUSY;
	129
	130	ks8695_wdt_start();
	131	return nonseekable_open(inode, file);
	132	}
	133
	134	/*
	135	* Close the watchdog device.
	136	* If CONFIG_WATCHDOG_NOWAYOUT is NOT defined then the watchdog is also
	137	* disabled.
	138	*/
	139	static int ks8695_wdt_close(struct inode inode, struct file file)
	140	{
f4fabce1	141	/* Disable the watchdog when file is closed */
ccb8f430	142	if (!nowayout)
f4fabce1	143	ks8695_wdt_stop();
ccb8f430 AV	144	clear_bit(0, &ks8695wdt_busy);
	145	return 0;
	146	}
	147
42747d71	148	static const struct watchdog_info ks8695_wdt_info = {
ccb8f430 AV	149	.identity = "ks8695 watchdog",
	150	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	151	};
	152
	153	/*
	154	* Handle commands from user-space.
	155	*/
f4fabce1 AC	156	static long ks8695_wdt_ioctl(struct file *file, unsigned int cmd,
f4fabce1 AC	157	unsigned long arg)
ccb8f430 AV	158	{
	159	void __user argp = (void __user )arg;
	160	int __user *p = argp;
	161	int new_value;
	162
f4fabce1	163	switch (cmd) {
f4fabce1 AC	164	case WDIOC_GETSUPPORT:
	165	return copy_to_user(argp, &ks8695_wdt_info,
	166	sizeof(ks8695_wdt_info)) ? -EFAULT : 0;
f4fabce1 AC	167	case WDIOC_GETSTATUS:
	168	case WDIOC_GETBOOTSTATUS:
	169	return put_user(0, p);
	170	case WDIOC_SETOPTIONS:
	171	if (get_user(new_value, p))
	172	return -EFAULT;
	173	if (new_value & WDIOS_DISABLECARD)
	174	ks8695_wdt_stop();
	175	if (new_value & WDIOS_ENABLECARD)
ccb8f430	176	ks8695_wdt_start();
f4fabce1	177	return 0;
0c06090c WVS	178	case WDIOC_KEEPALIVE:
	179	ks8695_wdt_reload(); /* pat the watchdog */
	180	return 0;
	181	case WDIOC_SETTIMEOUT:
	182	if (get_user(new_value, p))
	183	return -EFAULT;
	184	if (ks8695_wdt_settimeout(new_value))
	185	return -EINVAL;
	186	/* Enable new time value */
	187	ks8695_wdt_start();
	188	/* Return current value */
	189	return put_user(wdt_time, p);
	190	case WDIOC_GETTIMEOUT:
	191	return put_user(wdt_time, p);
f4fabce1 AC	192	default:
f4fabce1 AC	193	return -ENOTTY;
ccb8f430 AV	194	}
	195	}
	196
	197	/*
	198	* Pat the watchdog whenever device is written to.
	199	*/
f4fabce1 AC	200	static ssize_t ks8695_wdt_write(struct file file, const char data,
f4fabce1 AC	201	size_t len, loff_t *ppos)
ccb8f430 AV	202	{
	203	ks8695_wdt_reload(); /* pat the watchdog */
	204	return len;
	205	}
	206
	207	/* ......................................................................... */
	208
	209	static const struct file_operations ks8695wdt_fops = {
	210	.owner = THIS_MODULE,
	211	.llseek = no_llseek,
f4fabce1	212	.unlocked_ioctl = ks8695_wdt_ioctl,
ccb8f430 AV	213	.open = ks8695_wdt_open,
	214	.release = ks8695_wdt_close,
	215	.write = ks8695_wdt_write,
	216	};
	217
	218	static struct miscdevice ks8695wdt_miscdev = {
	219	.minor = WATCHDOG_MINOR,
	220	.name = "watchdog",
	221	.fops = &ks8695wdt_fops,
	222	};
	223
c98d58e0	224	static int __devinit ks8695wdt_probe(struct platform_device *pdev)
ccb8f430 AV	225	{
	226	int res;
	227
	228	if (ks8695wdt_miscdev.parent)
	229	return -EBUSY;
	230	ks8695wdt_miscdev.parent = &pdev->dev;
	231
	232	res = misc_register(&ks8695wdt_miscdev);
	233	if (res)
	234	return res;
	235
f4fabce1 AC	236	printk(KERN_INFO "KS8695 Watchdog Timer enabled (%d seconds%s)\n",
f4fabce1 AC	237	wdt_time, nowayout ? ", nowayout" : "");
ccb8f430 AV	238	return 0;
	239	}
	240
c98d58e0	241	static int __devexit ks8695wdt_remove(struct platform_device *pdev)
ccb8f430 AV	242	{
	243	int res;
	244
	245	res = misc_deregister(&ks8695wdt_miscdev);
	246	if (!res)
	247	ks8695wdt_miscdev.parent = NULL;
	248
	249	return res;
	250	}
	251
	252	static void ks8695wdt_shutdown(struct platform_device *pdev)
	253	{
	254	ks8695_wdt_stop();
	255	}
	256
	257	#ifdef CONFIG_PM
	258
	259	static int ks8695wdt_suspend(struct platform_device *pdev, pm_message_t message)
	260	{
	261	ks8695_wdt_stop();
	262	return 0;
	263	}
	264
	265	static int ks8695wdt_resume(struct platform_device *pdev)
	266	{
	267	if (ks8695wdt_busy)
	268	ks8695_wdt_start();
	269	return 0;
	270	}
	271
	272	#else
	273	#define ks8695wdt_suspend NULL
	274	#define ks8695wdt_resume NULL
	275	#endif
	276
	277	static struct platform_driver ks8695wdt_driver = {
	278	.probe = ks8695wdt_probe,
c98d58e0	279	.remove = __devexit_p(ks8695wdt_remove),
ccb8f430 AV	280	.shutdown = ks8695wdt_shutdown,
	281	.suspend = ks8695wdt_suspend,
	282	.resume = ks8695wdt_resume,
	283	.driver = {
	284	.name = "ks8695_wdt",
	285	.owner = THIS_MODULE,
	286	},
	287	};
	288
	289	static int __init ks8695_wdt_init(void)
	290	{
f4fabce1 AC	291	spin_lock_init(&ks8695_lock);
	292	/* Check that the heartbeat value is within range;
	293	if not reset to the default */
ccb8f430 AV	294	if (ks8695_wdt_settimeout(wdt_time)) {
ccb8f430 AV	295	ks8695_wdt_settimeout(WDT_DEFAULT_TIME);
a77dba7e WVS	296	pr_info("ks8695_wdt: wdt_time value must be 1 <= wdt_time <= %i"
a77dba7e WVS	297	", using %d\n", wdt_time, WDT_MAX_TIME);
ccb8f430	298	}
ccb8f430 AV	299	return platform_driver_register(&ks8695wdt_driver);
	300	}
	301
	302	static void __exit ks8695_wdt_exit(void)
	303	{
	304	platform_driver_unregister(&ks8695wdt_driver);
	305	}
	306
	307	module_init(ks8695_wdt_init);
	308	module_exit(ks8695_wdt_exit);
	309
	310	MODULE_AUTHOR("Andrew Victor");
	311	MODULE_DESCRIPTION("Watchdog driver for KS8695");
	312	MODULE_LICENSE("GPL");
	313	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
f37d193c	314	MODULE_ALIAS("platform:ks8695_wdt");