[net-next-2.6.git] / drivers / watchdog / mtx-1_wdt.c

/*
 *      Driver for the MTX-1 Watchdog.
 *
 *      (C) Copyright 2005 4G Systems <info@4g-systems.biz>,
 *							All Rights Reserved.
 *                              http://www.4g-systems.biz
 *
 * 	(C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
 *
 *      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.
 *
 *      Neither Michael Stickel nor 4G Systems admit liability nor provide
 *      warranty for any of this software. This material is provided
 *      "AS-IS" and at no charge.
 *
 *      (c) Copyright 2005    4G Systems <info@4g-systems.biz>
 *
 *      Release 0.01.
 *      Author: Michael Stickel  michael.stickel@4g-systems.biz
 *
 *      Release 0.02.
 *	Author: Florian Fainelli florian@openwrt.org
 *		use the Linux watchdog/timer APIs
 *
 *      The Watchdog is configured to reset the MTX-1
 *      if it is not triggered for 100 seconds.
 *      It should not be triggered more often than 1.6 seconds.
 *
 *      A timer triggers the watchdog every 5 seconds, until
 *      it is opened for the first time. After the first open
 *      it MUST be triggered every 2..95 seconds.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/timer.h>
#include <linux/completion.h>
#include <linux/jiffies.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/gpio.h>

#include <asm/mach-au1x00/au1000.h>

#define MTX1_WDT_INTERVAL	(5 * HZ)

static int ticks = 100 * HZ;

static struct {
	struct completion stop;
	spinlock_t lock;
	int running;
	struct timer_list timer;
	int queue;
	int default_ticks;
	unsigned long inuse;
	unsigned gpio;
} mtx1_wdt_device;

static void mtx1_wdt_trigger(unsigned long unused)
{
	u32 tmp;

	spin_lock(&mtx1_wdt_device.lock);
	if (mtx1_wdt_device.running)
		ticks--;
	/*
	 * toggle GPIO2_15
	 */
	tmp = au_readl(GPIO2_DIR);
	tmp = (tmp & ~(1 << mtx1_wdt_device.gpio)) |
	      ((~tmp) & (1 << mtx1_wdt_device.gpio));
	au_writel(tmp, GPIO2_DIR);

	if (mtx1_wdt_device.queue && ticks)
		mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
	else
		complete(&mtx1_wdt_device.stop);
	spin_unlock(&mtx1_wdt_device.lock);
}

static void mtx1_wdt_reset(void)
{
	ticks = mtx1_wdt_device.default_ticks;
}


static void mtx1_wdt_start(void)
{
	spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
	if (!mtx1_wdt_device.queue) {
		mtx1_wdt_device.queue = 1;
		gpio_set_value(mtx1_wdt_device.gpio, 1);
		mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
	}
	mtx1_wdt_device.running++;
	spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
}

static int mtx1_wdt_stop(void)
{
	spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
	if (mtx1_wdt_device.queue) {
		mtx1_wdt_device.queue = 0;
		gpio_set_value(mtx1_wdt_device.gpio, 0);
	}
	ticks = mtx1_wdt_device.default_ticks;
	spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
	return 0;
}

/* Filesystem functions */

static int mtx1_wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
		return -EBUSY;
	return nonseekable_open(inode, file);
}


static int mtx1_wdt_release(struct inode *inode, struct file *file)
{
	clear_bit(0, &mtx1_wdt_device.inuse);
	return 0;
}

static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = (int __user *)argp;
	unsigned int value;
	static const struct watchdog_info ident = {
		.options = WDIOF_CARDRESET,
		.identity = "MTX-1 WDT",
	};

	switch (cmd) {
	case WDIOC_KEEPALIVE:
		mtx1_wdt_reset();
		break;
	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		put_user(0, p);
		break;
	case WDIOC_GETSUPPORT:
		if (copy_to_user(argp, &ident, sizeof(ident)))
			return -EFAULT;
		break;
	case WDIOC_SETOPTIONS:
		if (get_user(value, p))
			return -EFAULT;
		if (value & WDIOS_ENABLECARD)
			mtx1_wdt_start();
		else if (value & WDIOS_DISABLECARD)
			mtx1_wdt_stop();
		else
			return -EINVAL;
		return 0;
	default:
		return -ENOTTY;
	}
	return 0;
}


static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
						size_t count, loff_t *ppos)
{
	if (!count)
		return -EIO;
	mtx1_wdt_reset();
	return count;
}

static const struct file_operations mtx1_wdt_fops = {
	.owner 		= THIS_MODULE,
	.llseek		= no_llseek,
	.unlocked_ioctl	= mtx1_wdt_ioctl,
	.open 		= mtx1_wdt_open,
	.write 		= mtx1_wdt_write,
	.release 	= mtx1_wdt_release
};


static struct miscdevice mtx1_wdt_misc = {
	.minor 	= WATCHDOG_MINOR,
	.name 	= "watchdog",
	.fops 	= &mtx1_wdt_fops
};


static int mtx1_wdt_probe(struct platform_device *pdev)
{
	int ret;

	mtx1_wdt_device.gpio = pdev->resource[0].start;

	spin_lock_init(&mtx1_wdt_device.lock);
	init_completion(&mtx1_wdt_device.stop);
	mtx1_wdt_device.queue = 0;
	clear_bit(0, &mtx1_wdt_device.inuse);
	setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
	mtx1_wdt_device.default_ticks = ticks;

	ret = misc_register(&mtx1_wdt_misc);
	if (ret < 0) {
		printk(KERN_ERR " mtx-1_wdt : failed to register\n");
		return ret;
	}
	mtx1_wdt_start();
	printk(KERN_INFO "MTX-1 Watchdog driver\n");
	return 0;
}

static int mtx1_wdt_remove(struct platform_device *pdev)
{
	/* FIXME: do we need to lock this test ? */
	if (mtx1_wdt_device.queue) {
		mtx1_wdt_device.queue = 0;
		wait_for_completion(&mtx1_wdt_device.stop);
	}
	misc_deregister(&mtx1_wdt_misc);
	return 0;
}

static struct platform_driver mtx1_wdt = {
	.probe = mtx1_wdt_probe,
	.remove = mtx1_wdt_remove,
	.driver.name = "mtx1-wdt",
	.driver.owner = THIS_MODULE,
};

static int __init mtx1_wdt_init(void)
{
	return platform_driver_register(&mtx1_wdt);
}

static void __exit mtx1_wdt_exit(void)
{
	platform_driver_unregister(&mtx1_wdt);
}

module_init(mtx1_wdt_init);
module_exit(mtx1_wdt_exit);

MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS("platform:mtx1-wdt");
Commit	Line	Data
04bf3b4f FF	1	/*
	2	* Driver for the MTX-1 Watchdog.
	3	*
ed78c2da AC	4	* (C) Copyright 2005 4G Systems <info@4g-systems.biz>,
ed78c2da AC	5	* All Rights Reserved.
04bf3b4f FF	6	* http://www.4g-systems.biz
	7	*
	8	* (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
	9	*
	10	* This program is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU General Public License
	12	* as published by the Free Software Foundation; either version
	13	* 2 of the License, or (at your option) any later version.
	14	*
	15	* Neither Michael Stickel nor 4G Systems admit liability nor provide
	16	* warranty for any of this software. This material is provided
	17	* "AS-IS" and at no charge.
	18	*
	19	* (c) Copyright 2005 4G Systems <info@4g-systems.biz>
	20	*
	21	* Release 0.01.
	22	* Author: Michael Stickel michael.stickel@4g-systems.biz
	23	*
	24	* Release 0.02.
	25	* Author: Florian Fainelli florian@openwrt.org
	26	* use the Linux watchdog/timer APIs
	27	*
	28	* The Watchdog is configured to reset the MTX-1
	29	* if it is not triggered for 100 seconds.
	30	* It should not be triggered more often than 1.6 seconds.
	31	*
	32	* A timer triggers the watchdog every 5 seconds, until
	33	* it is opened for the first time. After the first open
	34	* it MUST be triggered every 2..95 seconds.
	35	*/
	36
	37	#include <linux/module.h>
	38	#include <linux/moduleparam.h>
	39	#include <linux/types.h>
	40	#include <linux/errno.h>
	41	#include <linux/miscdevice.h>
	42	#include <linux/fs.h>
	43	#include <linux/init.h>
	44	#include <linux/ioport.h>
	45	#include <linux/timer.h>
	46	#include <linux/completion.h>
	47	#include <linux/jiffies.h>
	48	#include <linux/watchdog.h>
6ea8115b	49	#include <linux/platform_device.h>
ed78c2da AC	50	#include <linux/io.h>
	51	#include <linux/uaccess.h>
	52	#include <linux/gpio.h>
04bf3b4f FF	53
	54	#include <asm/mach-au1x00/au1000.h>
	55
	56	#define MTX1_WDT_INTERVAL (5 * HZ)
	57
	58	static int ticks = 100 * HZ;
	59
	60	static struct {
	61	struct completion stop;
ed78c2da	62	spinlock_t lock;
996d62d4	63	int running;
04bf3b4f	64	struct timer_list timer;
996d62d4	65	int queue;
04bf3b4f FF	66	int default_ticks;
04bf3b4f FF	67	unsigned long inuse;
6ea8115b	68	unsigned gpio;
04bf3b4f FF	69	} mtx1_wdt_device;
	70
	71	static void mtx1_wdt_trigger(unsigned long unused)
	72	{
	73	u32 tmp;
	74
ed78c2da	75	spin_lock(&mtx1_wdt_device.lock);
04bf3b4f FF	76	if (mtx1_wdt_device.running)
	77	ticks--;
	78	/*
	79	* toggle GPIO2_15
	80	*/
	81	tmp = au_readl(GPIO2_DIR);
6ea8115b FF	82	tmp = (tmp & ~(1 << mtx1_wdt_device.gpio)) \|
6ea8115b FF	83	((~tmp) & (1 << mtx1_wdt_device.gpio));
ed78c2da	84	au_writel(tmp, GPIO2_DIR);
04bf3b4f FF	85
	86	if (mtx1_wdt_device.queue && ticks)
	87	mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
ed78c2da	88	else
04bf3b4f	89	complete(&mtx1_wdt_device.stop);
ed78c2da	90	spin_unlock(&mtx1_wdt_device.lock);
04bf3b4f FF	91	}
	92
	93	static void mtx1_wdt_reset(void)
	94	{
	95	ticks = mtx1_wdt_device.default_ticks;
	96	}
	97
	98
	99	static void mtx1_wdt_start(void)
	100	{
ed78c2da	101	spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	102	if (!mtx1_wdt_device.queue) {
04bf3b4f FF	103	mtx1_wdt_device.queue = 1;
6ea8115b	104	gpio_set_value(mtx1_wdt_device.gpio, 1);
04bf3b4f FF	105	mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
	106	}
	107	mtx1_wdt_device.running++;
ed78c2da	108	spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	109	}
	110
	111	static int mtx1_wdt_stop(void)
	112	{
ed78c2da	113	spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	114	if (mtx1_wdt_device.queue) {
04bf3b4f FF	115	mtx1_wdt_device.queue = 0;
6ea8115b	116	gpio_set_value(mtx1_wdt_device.gpio, 0);
04bf3b4f	117	}
04bf3b4f	118	ticks = mtx1_wdt_device.default_ticks;
ed78c2da	119	spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	120	return 0;
	121	}
	122
	123	/* Filesystem functions */
	124
	125	static int mtx1_wdt_open(struct inode inode, struct file file)
	126	{
	127	if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
	128	return -EBUSY;
04bf3b4f FF	129	return nonseekable_open(inode, file);
	130	}
	131
	132
	133	static int mtx1_wdt_release(struct inode inode, struct file file)
	134	{
	135	clear_bit(0, &mtx1_wdt_device.inuse);
	136	return 0;
	137	}
	138
ed78c2da AC	139	static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
ed78c2da AC	140	unsigned long arg)
04bf3b4f FF	141	{
04bf3b4f FF	142	void __user argp = (void __user )arg;
ed78c2da	143	int __user p = (int __user )argp;
04bf3b4f	144	unsigned int value;
ed78c2da	145	static const struct watchdog_info ident = {
04bf3b4f FF	146	.options = WDIOF_CARDRESET,
	147	.identity = "MTX-1 WDT",
	148	};
	149
ed78c2da AC	150	switch (cmd) {
	151	case WDIOC_KEEPALIVE:
	152	mtx1_wdt_reset();
	153	break;
	154	case WDIOC_GETSTATUS:
	155	case WDIOC_GETBOOTSTATUS:
	156	put_user(0, p);
	157	break;
	158	case WDIOC_GETSUPPORT:
	159	if (copy_to_user(argp, &ident, sizeof(ident)))
	160	return -EFAULT;
	161	break;
	162	case WDIOC_SETOPTIONS:
	163	if (get_user(value, p))
	164	return -EFAULT;
	165	if (value & WDIOS_ENABLECARD)
	166	mtx1_wdt_start();
	167	else if (value & WDIOS_DISABLECARD)
	168	mtx1_wdt_stop();
	169	else
	170	return -EINVAL;
	171	return 0;
	172	default:
	173	return -ENOTTY;
04bf3b4f FF	174	}
	175	return 0;
	176	}
	177
	178
ed78c2da AC	179	static ssize_t mtx1_wdt_write(struct file file, const char buf,
ed78c2da AC	180	size_t count, loff_t *ppos)
04bf3b4f FF	181	{
	182	if (!count)
	183	return -EIO;
04bf3b4f FF	184	mtx1_wdt_reset();
	185	return count;
	186	}
	187
b47a166e	188	static const struct file_operations mtx1_wdt_fops = {
04bf3b4f FF	189	.owner = THIS_MODULE,
04bf3b4f FF	190	.llseek = no_llseek,
ed78c2da	191	.unlocked_ioctl = mtx1_wdt_ioctl,
04bf3b4f FF	192	.open = mtx1_wdt_open,
	193	.write = mtx1_wdt_write,
	194	.release = mtx1_wdt_release
	195	};
	196
	197
	198	static struct miscdevice mtx1_wdt_misc = {
	199	.minor = WATCHDOG_MINOR,
	200	.name = "watchdog",
	201	.fops = &mtx1_wdt_fops
	202	};
	203
	204
6ea8115b	205	static int mtx1_wdt_probe(struct platform_device *pdev)
04bf3b4f FF	206	{
	207	int ret;
	208
6ea8115b FF	209	mtx1_wdt_device.gpio = pdev->resource[0].start;
6ea8115b FF	210
ed78c2da	211	spin_lock_init(&mtx1_wdt_device.lock);
04bf3b4f FF	212	init_completion(&mtx1_wdt_device.stop);
04bf3b4f FF	213	mtx1_wdt_device.queue = 0;
04bf3b4f	214	clear_bit(0, &mtx1_wdt_device.inuse);
04bf3b4f	215	setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
04bf3b4f FF	216	mtx1_wdt_device.default_ticks = ticks;
04bf3b4f FF	217
ed78c2da AC	218	ret = misc_register(&mtx1_wdt_misc);
	219	if (ret < 0) {
	220	printk(KERN_ERR " mtx-1_wdt : failed to register\n");
	221	return ret;
	222	}
04bf3b4f	223	mtx1_wdt_start();
04bf3b4f	224	printk(KERN_INFO "MTX-1 Watchdog driver\n");
04bf3b4f FF	225	return 0;
	226	}
	227
6ea8115b	228	static int mtx1_wdt_remove(struct platform_device *pdev)
04bf3b4f	229	{
ed78c2da	230	/* FIXME: do we need to lock this test ? */
04bf3b4f FF	231	if (mtx1_wdt_device.queue) {
	232	mtx1_wdt_device.queue = 0;
	233	wait_for_completion(&mtx1_wdt_device.stop);
	234	}
	235	misc_deregister(&mtx1_wdt_misc);
6ea8115b FF	236	return 0;
	237	}
	238
	239	static struct platform_driver mtx1_wdt = {
	240	.probe = mtx1_wdt_probe,
	241	.remove = mtx1_wdt_remove,
	242	.driver.name = "mtx1-wdt",
f37d193c	243	.driver.owner = THIS_MODULE,
6ea8115b FF	244	};
	245
	246	static int __init mtx1_wdt_init(void)
	247	{
	248	return platform_driver_register(&mtx1_wdt);
	249	}
	250
	251	static void __exit mtx1_wdt_exit(void)
	252	{
	253	platform_driver_unregister(&mtx1_wdt);
04bf3b4f FF	254	}
	255
	256	module_init(mtx1_wdt_init);
	257	module_exit(mtx1_wdt_exit);
	258
	259	MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
	260	MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
	261	MODULE_LICENSE("GPL");
6ea8115b	262	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
f37d193c	263	MODULE_ALIAS("platform:mtx1-wdt");