[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)
{
	unsigned long flags;

	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)
{
	unsigned long flags;

	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_GETSUPPORT:
		if (copy_to_user(argp, &ident, sizeof(ident)))
			return -EFAULT;
		break;
	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		put_user(0, p);
		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;
	case WDIOC_KEEPALIVE:
		mtx1_wdt_reset();
		break;
	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 __devinit 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 __devexit 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 = __devexit_p(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
04bf3b4f FF	7	*
143a2e54	8	* (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
04bf3b4f FF	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	{
f80e919b FF	101	unsigned long flags;
f80e919b FF	102
ed78c2da	103	spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	104	if (!mtx1_wdt_device.queue) {
04bf3b4f FF	105	mtx1_wdt_device.queue = 1;
6ea8115b	106	gpio_set_value(mtx1_wdt_device.gpio, 1);
04bf3b4f FF	107	mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
	108	}
	109	mtx1_wdt_device.running++;
ed78c2da	110	spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	111	}
	112
	113	static int mtx1_wdt_stop(void)
	114	{
f80e919b FF	115	unsigned long flags;
f80e919b FF	116
ed78c2da	117	spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	118	if (mtx1_wdt_device.queue) {
04bf3b4f FF	119	mtx1_wdt_device.queue = 0;
6ea8115b	120	gpio_set_value(mtx1_wdt_device.gpio, 0);
04bf3b4f	121	}
04bf3b4f	122	ticks = mtx1_wdt_device.default_ticks;
ed78c2da	123	spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	124	return 0;
	125	}
	126
	127	/* Filesystem functions */
	128
	129	static int mtx1_wdt_open(struct inode inode, struct file file)
	130	{
	131	if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
	132	return -EBUSY;
04bf3b4f FF	133	return nonseekable_open(inode, file);
	134	}
	135
	136
	137	static int mtx1_wdt_release(struct inode inode, struct file file)
	138	{
	139	clear_bit(0, &mtx1_wdt_device.inuse);
	140	return 0;
	141	}
	142
ed78c2da AC	143	static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
ed78c2da AC	144	unsigned long arg)
04bf3b4f FF	145	{
04bf3b4f FF	146	void __user argp = (void __user )arg;
ed78c2da	147	int __user p = (int __user )argp;
04bf3b4f	148	unsigned int value;
ed78c2da	149	static const struct watchdog_info ident = {
04bf3b4f FF	150	.options = WDIOF_CARDRESET,
	151	.identity = "MTX-1 WDT",
	152	};
	153
ed78c2da	154	switch (cmd) {
0c06090c WVS	155	case WDIOC_GETSUPPORT:
	156	if (copy_to_user(argp, &ident, sizeof(ident)))
	157	return -EFAULT;
ed78c2da AC	158	break;
	159	case WDIOC_GETSTATUS:
	160	case WDIOC_GETBOOTSTATUS:
	161	put_user(0, p);
	162	break;
ed78c2da AC	163	case WDIOC_SETOPTIONS:
	164	if (get_user(value, p))
	165	return -EFAULT;
	166	if (value & WDIOS_ENABLECARD)
	167	mtx1_wdt_start();
	168	else if (value & WDIOS_DISABLECARD)
	169	mtx1_wdt_stop();
	170	else
	171	return -EINVAL;
	172	return 0;
0c06090c WVS	173	case WDIOC_KEEPALIVE:
	174	mtx1_wdt_reset();
	175	break;
ed78c2da AC	176	default:
ed78c2da AC	177	return -ENOTTY;
04bf3b4f FF	178	}
	179	return 0;
	180	}
	181
	182
ed78c2da AC	183	static ssize_t mtx1_wdt_write(struct file file, const char buf,
ed78c2da AC	184	size_t count, loff_t *ppos)
04bf3b4f FF	185	{
	186	if (!count)
	187	return -EIO;
04bf3b4f FF	188	mtx1_wdt_reset();
	189	return count;
	190	}
	191
b47a166e	192	static const struct file_operations mtx1_wdt_fops = {
04bf3b4f FF	193	.owner = THIS_MODULE,
04bf3b4f FF	194	.llseek = no_llseek,
ed78c2da	195	.unlocked_ioctl = mtx1_wdt_ioctl,
04bf3b4f FF	196	.open = mtx1_wdt_open,
04bf3b4f FF	197	.write = mtx1_wdt_write,
7944d3a5	198	.release = mtx1_wdt_release,
04bf3b4f FF	199	};
	200
	201
	202	static struct miscdevice mtx1_wdt_misc = {
	203	.minor = WATCHDOG_MINOR,
	204	.name = "watchdog",
7944d3a5	205	.fops = &mtx1_wdt_fops,
04bf3b4f FF	206	};
	207
	208
b6bf291f	209	static int __devinit mtx1_wdt_probe(struct platform_device *pdev)
04bf3b4f FF	210	{
	211	int ret;
	212
6ea8115b FF	213	mtx1_wdt_device.gpio = pdev->resource[0].start;
6ea8115b FF	214
ed78c2da	215	spin_lock_init(&mtx1_wdt_device.lock);
04bf3b4f FF	216	init_completion(&mtx1_wdt_device.stop);
04bf3b4f FF	217	mtx1_wdt_device.queue = 0;
04bf3b4f	218	clear_bit(0, &mtx1_wdt_device.inuse);
04bf3b4f	219	setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
04bf3b4f FF	220	mtx1_wdt_device.default_ticks = ticks;
04bf3b4f FF	221
ed78c2da AC	222	ret = misc_register(&mtx1_wdt_misc);
	223	if (ret < 0) {
	224	printk(KERN_ERR " mtx-1_wdt : failed to register\n");
	225	return ret;
	226	}
04bf3b4f	227	mtx1_wdt_start();
04bf3b4f	228	printk(KERN_INFO "MTX-1 Watchdog driver\n");
04bf3b4f FF	229	return 0;
	230	}
	231
b6bf291f	232	static int __devexit mtx1_wdt_remove(struct platform_device *pdev)
04bf3b4f	233	{
ed78c2da	234	/* FIXME: do we need to lock this test ? */
04bf3b4f FF	235	if (mtx1_wdt_device.queue) {
	236	mtx1_wdt_device.queue = 0;
	237	wait_for_completion(&mtx1_wdt_device.stop);
	238	}
	239	misc_deregister(&mtx1_wdt_misc);
6ea8115b FF	240	return 0;
	241	}
	242
	243	static struct platform_driver mtx1_wdt = {
	244	.probe = mtx1_wdt_probe,
b6bf291f	245	.remove = __devexit_p(mtx1_wdt_remove),
6ea8115b	246	.driver.name = "mtx1-wdt",
f37d193c	247	.driver.owner = THIS_MODULE,
6ea8115b FF	248	};
	249
	250	static int __init mtx1_wdt_init(void)
	251	{
	252	return platform_driver_register(&mtx1_wdt);
	253	}
	254
	255	static void __exit mtx1_wdt_exit(void)
	256	{
	257	platform_driver_unregister(&mtx1_wdt);
04bf3b4f FF	258	}
	259
	260	module_init(mtx1_wdt_init);
	261	module_exit(mtx1_wdt_exit);
	262
	263	MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
	264	MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
	265	MODULE_LICENSE("GPL");
6ea8115b	266	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
f37d193c	267	MODULE_ALIAS("platform:mtx1-wdt");