[mirror_ubuntu-bionic-kernel.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;
	int gstate;
} 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 wdt gpio */
	mtx1_wdt_device.gstate = ~mtx1_wdt_device.gstate;
	if (mtx1_wdt_device.gstate)
		gpio_direction_output(mtx1_wdt_device.gpio, 1);
	else
		gpio_direction_input(mtx1_wdt_device.gpio);

	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;
		mtx1_wdt_device.gstate = 1;
		gpio_direction_output(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;
		mtx1_wdt_device.gstate = 0;
		gpio_direction_output(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;
	ret = gpio_request_one(mtx1_wdt_device.gpio,
				GPIOF_OUT_INIT_HIGH, "mtx1-wdt");
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to request gpio");
		return ret;
	}

	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);
	}

	gpio_free(mtx1_wdt_device.gpio);
	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;
b7f720d6	69	int gstate;
04bf3b4f FF	70	} mtx1_wdt_device;
	71
	72	static void mtx1_wdt_trigger(unsigned long unused)
	73	{
	74	u32 tmp;
	75
ed78c2da	76	spin_lock(&mtx1_wdt_device.lock);
04bf3b4f FF	77	if (mtx1_wdt_device.running)
04bf3b4f FF	78	ticks--;
b7f720d6 ML	79
	80	/* toggle wdt gpio */
	81	mtx1_wdt_device.gstate = ~mtx1_wdt_device.gstate;
	82	if (mtx1_wdt_device.gstate)
	83	gpio_direction_output(mtx1_wdt_device.gpio, 1);
	84	else
	85	gpio_direction_input(mtx1_wdt_device.gpio);
04bf3b4f FF	86
	87	if (mtx1_wdt_device.queue && ticks)
	88	mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
ed78c2da	89	else
04bf3b4f	90	complete(&mtx1_wdt_device.stop);
ed78c2da	91	spin_unlock(&mtx1_wdt_device.lock);
04bf3b4f FF	92	}
	93
	94	static void mtx1_wdt_reset(void)
	95	{
	96	ticks = mtx1_wdt_device.default_ticks;
	97	}
	98
	99
	100	static void mtx1_wdt_start(void)
	101	{
f80e919b FF	102	unsigned long flags;
f80e919b FF	103
ed78c2da	104	spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	105	if (!mtx1_wdt_device.queue) {
04bf3b4f FF	106	mtx1_wdt_device.queue = 1;
b7f720d6 ML	107	mtx1_wdt_device.gstate = 1;
b7f720d6 ML	108	gpio_direction_output(mtx1_wdt_device.gpio, 1);
04bf3b4f FF	109	mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
	110	}
	111	mtx1_wdt_device.running++;
ed78c2da	112	spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	113	}
	114
	115	static int mtx1_wdt_stop(void)
	116	{
f80e919b FF	117	unsigned long flags;
f80e919b FF	118
ed78c2da	119	spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	120	if (mtx1_wdt_device.queue) {
04bf3b4f FF	121	mtx1_wdt_device.queue = 0;
b7f720d6 ML	122	mtx1_wdt_device.gstate = 0;
b7f720d6 ML	123	gpio_direction_output(mtx1_wdt_device.gpio, 0);
04bf3b4f	124	}
04bf3b4f	125	ticks = mtx1_wdt_device.default_ticks;
ed78c2da	126	spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	127	return 0;
	128	}
	129
	130	/* Filesystem functions */
	131
	132	static int mtx1_wdt_open(struct inode inode, struct file file)
	133	{
	134	if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
	135	return -EBUSY;
04bf3b4f FF	136	return nonseekable_open(inode, file);
	137	}
	138
	139
	140	static int mtx1_wdt_release(struct inode inode, struct file file)
	141	{
	142	clear_bit(0, &mtx1_wdt_device.inuse);
	143	return 0;
	144	}
	145
ed78c2da AC	146	static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
ed78c2da AC	147	unsigned long arg)
04bf3b4f FF	148	{
04bf3b4f FF	149	void __user argp = (void __user )arg;
ed78c2da	150	int __user p = (int __user )argp;
04bf3b4f	151	unsigned int value;
ed78c2da	152	static const struct watchdog_info ident = {
04bf3b4f FF	153	.options = WDIOF_CARDRESET,
	154	.identity = "MTX-1 WDT",
	155	};
	156
ed78c2da	157	switch (cmd) {
0c06090c WVS	158	case WDIOC_GETSUPPORT:
	159	if (copy_to_user(argp, &ident, sizeof(ident)))
	160	return -EFAULT;
ed78c2da AC	161	break;
	162	case WDIOC_GETSTATUS:
	163	case WDIOC_GETBOOTSTATUS:
	164	put_user(0, p);
	165	break;
ed78c2da AC	166	case WDIOC_SETOPTIONS:
	167	if (get_user(value, p))
	168	return -EFAULT;
	169	if (value & WDIOS_ENABLECARD)
	170	mtx1_wdt_start();
	171	else if (value & WDIOS_DISABLECARD)
	172	mtx1_wdt_stop();
	173	else
	174	return -EINVAL;
	175	return 0;
0c06090c WVS	176	case WDIOC_KEEPALIVE:
	177	mtx1_wdt_reset();
	178	break;
ed78c2da AC	179	default:
ed78c2da AC	180	return -ENOTTY;
04bf3b4f FF	181	}
	182	return 0;
	183	}
	184
	185
ed78c2da AC	186	static ssize_t mtx1_wdt_write(struct file file, const char buf,
ed78c2da AC	187	size_t count, loff_t *ppos)
04bf3b4f FF	188	{
	189	if (!count)
	190	return -EIO;
04bf3b4f FF	191	mtx1_wdt_reset();
	192	return count;
	193	}
	194
b47a166e	195	static const struct file_operations mtx1_wdt_fops = {
5f3b2756	196	.owner = THIS_MODULE,
04bf3b4f	197	.llseek = no_llseek,
ed78c2da	198	.unlocked_ioctl = mtx1_wdt_ioctl,
5f3b2756 WVS	199	.open = mtx1_wdt_open,
	200	.write = mtx1_wdt_write,
	201	.release = mtx1_wdt_release,
04bf3b4f FF	202	};
	203
	204
	205	static struct miscdevice mtx1_wdt_misc = {
5f3b2756 WVS	206	.minor = WATCHDOG_MINOR,
	207	.name = "watchdog",
	208	.fops = &mtx1_wdt_fops,
04bf3b4f FF	209	};
	210
	211
b6bf291f	212	static int __devinit mtx1_wdt_probe(struct platform_device *pdev)
04bf3b4f FF	213	{
	214	int ret;
	215
6ea8115b	216	mtx1_wdt_device.gpio = pdev->resource[0].start;
9b19d40a FF	217	ret = gpio_request_one(mtx1_wdt_device.gpio,
	218	GPIOF_OUT_INIT_HIGH, "mtx1-wdt");
	219	if (ret < 0) {
	220	dev_err(&pdev->dev, "failed to request gpio");
	221	return ret;
	222	}
6ea8115b	223
ed78c2da	224	spin_lock_init(&mtx1_wdt_device.lock);
04bf3b4f FF	225	init_completion(&mtx1_wdt_device.stop);
04bf3b4f FF	226	mtx1_wdt_device.queue = 0;
04bf3b4f	227	clear_bit(0, &mtx1_wdt_device.inuse);
04bf3b4f	228	setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
04bf3b4f FF	229	mtx1_wdt_device.default_ticks = ticks;
04bf3b4f FF	230
ed78c2da AC	231	ret = misc_register(&mtx1_wdt_misc);
	232	if (ret < 0) {
	233	printk(KERN_ERR " mtx-1_wdt : failed to register\n");
	234	return ret;
	235	}
04bf3b4f	236	mtx1_wdt_start();
04bf3b4f	237	printk(KERN_INFO "MTX-1 Watchdog driver\n");
04bf3b4f FF	238	return 0;
	239	}
	240
b6bf291f	241	static int __devexit mtx1_wdt_remove(struct platform_device *pdev)
04bf3b4f	242	{
ed78c2da	243	/* FIXME: do we need to lock this test ? */
04bf3b4f FF	244	if (mtx1_wdt_device.queue) {
	245	mtx1_wdt_device.queue = 0;
	246	wait_for_completion(&mtx1_wdt_device.stop);
	247	}
9b19d40a FF	248
9b19d40a FF	249	gpio_free(mtx1_wdt_device.gpio);
04bf3b4f	250	misc_deregister(&mtx1_wdt_misc);
6ea8115b FF	251	return 0;
	252	}
	253
	254	static struct platform_driver mtx1_wdt = {
	255	.probe = mtx1_wdt_probe,
b6bf291f	256	.remove = __devexit_p(mtx1_wdt_remove),
6ea8115b	257	.driver.name = "mtx1-wdt",
f37d193c	258	.driver.owner = THIS_MODULE,
6ea8115b FF	259	};
	260
	261	static int __init mtx1_wdt_init(void)
	262	{
	263	return platform_driver_register(&mtx1_wdt);
	264	}
	265
	266	static void __exit mtx1_wdt_exit(void)
	267	{
	268	platform_driver_unregister(&mtx1_wdt);
04bf3b4f FF	269	}
	270
	271	module_init(mtx1_wdt_init);
	272	module_exit(mtx1_wdt_exit);
	273
	274	MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
	275	MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
	276	MODULE_LICENSE("GPL");
6ea8115b	277	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
f37d193c	278	MODULE_ALIAS("platform:mtx1-wdt");