[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/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;
	unsigned int gstate;
} mtx1_wdt_device;

static void mtx1_wdt_trigger(struct timer_list *unused)
{
	spin_lock(&mtx1_wdt_device.lock);
	if (mtx1_wdt_device.running)
		ticks--;

	/* toggle wdt gpio */
	mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate;
	gpio_set_value(mtx1_wdt_device.gpio, mtx1_wdt_device.gstate);

	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_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;
		mtx1_wdt_device.gstate = 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 mtx1_wdt_probe(struct platform_device *pdev)
{
	int ret;

	mtx1_wdt_device.gpio = pdev->resource[0].start;
	ret = devm_gpio_request_one(&pdev->dev, 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);
	timer_setup(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0);
	mtx1_wdt_device.default_ticks = ticks;

	ret = misc_register(&mtx1_wdt_misc);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to register\n");
		return ret;
	}
	mtx1_wdt_start();
	dev_info(&pdev->dev, "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_driver = {
	.probe = mtx1_wdt_probe,
	.remove = mtx1_wdt_remove,
	.driver.name = "mtx1-wdt",
	.driver.owner = THIS_MODULE,
};

module_platform_driver(mtx1_wdt_driver);

MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
MODULE_LICENSE("GPL");
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>
04bf3b4f FF	43	#include <linux/ioport.h>
	44	#include <linux/timer.h>
	45	#include <linux/completion.h>
	46	#include <linux/jiffies.h>
	47	#include <linux/watchdog.h>
6ea8115b	48	#include <linux/platform_device.h>
ed78c2da AC	49	#include <linux/io.h>
	50	#include <linux/uaccess.h>
	51	#include <linux/gpio.h>
04bf3b4f FF	52
	53	#include <asm/mach-au1x00/au1000.h>
	54
	55	#define MTX1_WDT_INTERVAL (5 * HZ)
	56
	57	static int ticks = 100 * HZ;
	58
	59	static struct {
	60	struct completion stop;
ed78c2da	61	spinlock_t lock;
996d62d4	62	int running;
04bf3b4f	63	struct timer_list timer;
996d62d4	64	int queue;
04bf3b4f FF	65	int default_ticks;
04bf3b4f FF	66	unsigned long inuse;
6ea8115b	67	unsigned gpio;
2ea4e76e	68	unsigned int gstate;
04bf3b4f FF	69	} mtx1_wdt_device;
04bf3b4f FF	70
e99e88a9	71	static void mtx1_wdt_trigger(struct timer_list *unused)
04bf3b4f	72	{
ed78c2da	73	spin_lock(&mtx1_wdt_device.lock);
04bf3b4f FF	74	if (mtx1_wdt_device.running)
04bf3b4f FF	75	ticks--;
b7f720d6 ML	76
b7f720d6 ML	77	/* toggle wdt gpio */
2ea4e76e FF	78	mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate;
2ea4e76e FF	79	gpio_set_value(mtx1_wdt_device.gpio, mtx1_wdt_device.gstate);
04bf3b4f FF	80
	81	if (mtx1_wdt_device.queue && ticks)
	82	mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
ed78c2da	83	else
04bf3b4f	84	complete(&mtx1_wdt_device.stop);
ed78c2da	85	spin_unlock(&mtx1_wdt_device.lock);
04bf3b4f FF	86	}
	87
	88	static void mtx1_wdt_reset(void)
	89	{
	90	ticks = mtx1_wdt_device.default_ticks;
	91	}
	92
	93
	94	static void mtx1_wdt_start(void)
	95	{
f80e919b FF	96	unsigned long flags;
f80e919b FF	97
ed78c2da	98	spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	99	if (!mtx1_wdt_device.queue) {
04bf3b4f FF	100	mtx1_wdt_device.queue = 1;
b7f720d6	101	mtx1_wdt_device.gstate = 1;
2ea4e76e	102	gpio_set_value(mtx1_wdt_device.gpio, 1);
04bf3b4f FF	103	mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
	104	}
	105	mtx1_wdt_device.running++;
ed78c2da	106	spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	107	}
	108
	109	static int mtx1_wdt_stop(void)
	110	{
f80e919b FF	111	unsigned long flags;
f80e919b FF	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;
b7f720d6	116	mtx1_wdt_device.gstate = 0;
2ea4e76e	117	gpio_set_value(mtx1_wdt_device.gpio, 0);
04bf3b4f	118	}
04bf3b4f	119	ticks = mtx1_wdt_device.default_ticks;
ed78c2da	120	spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
04bf3b4f FF	121	return 0;
	122	}
	123
	124	/* Filesystem functions */
	125
	126	static int mtx1_wdt_open(struct inode inode, struct file file)
	127	{
	128	if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
	129	return -EBUSY;
04bf3b4f FF	130	return nonseekable_open(inode, file);
	131	}
	132
	133
	134	static int mtx1_wdt_release(struct inode inode, struct file file)
	135	{
	136	clear_bit(0, &mtx1_wdt_device.inuse);
	137	return 0;
	138	}
	139
ed78c2da AC	140	static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
ed78c2da AC	141	unsigned long arg)
04bf3b4f FF	142	{
04bf3b4f FF	143	void __user argp = (void __user )arg;
ed78c2da	144	int __user p = (int __user )argp;
04bf3b4f	145	unsigned int value;
ed78c2da	146	static const struct watchdog_info ident = {
04bf3b4f FF	147	.options = WDIOF_CARDRESET,
	148	.identity = "MTX-1 WDT",
	149	};
	150
ed78c2da	151	switch (cmd) {
0c06090c WVS	152	case WDIOC_GETSUPPORT:
	153	if (copy_to_user(argp, &ident, sizeof(ident)))
	154	return -EFAULT;
ed78c2da AC	155	break;
	156	case WDIOC_GETSTATUS:
	157	case WDIOC_GETBOOTSTATUS:
	158	put_user(0, p);
	159	break;
ed78c2da AC	160	case WDIOC_SETOPTIONS:
	161	if (get_user(value, p))
	162	return -EFAULT;
	163	if (value & WDIOS_ENABLECARD)
	164	mtx1_wdt_start();
	165	else if (value & WDIOS_DISABLECARD)
	166	mtx1_wdt_stop();
	167	else
	168	return -EINVAL;
	169	return 0;
0c06090c WVS	170	case WDIOC_KEEPALIVE:
	171	mtx1_wdt_reset();
	172	break;
ed78c2da AC	173	default:
ed78c2da AC	174	return -ENOTTY;
04bf3b4f FF	175	}
	176	return 0;
	177	}
	178
	179
ed78c2da AC	180	static ssize_t mtx1_wdt_write(struct file file, const char buf,
ed78c2da AC	181	size_t count, loff_t *ppos)
04bf3b4f FF	182	{
	183	if (!count)
	184	return -EIO;
04bf3b4f FF	185	mtx1_wdt_reset();
	186	return count;
	187	}
	188
b47a166e	189	static const struct file_operations mtx1_wdt_fops = {
5f3b2756	190	.owner = THIS_MODULE,
04bf3b4f	191	.llseek = no_llseek,
ed78c2da	192	.unlocked_ioctl = mtx1_wdt_ioctl,
5f3b2756 WVS	193	.open = mtx1_wdt_open,
	194	.write = mtx1_wdt_write,
	195	.release = mtx1_wdt_release,
04bf3b4f FF	196	};
	197
	198
	199	static struct miscdevice mtx1_wdt_misc = {
5f3b2756 WVS	200	.minor = WATCHDOG_MINOR,
	201	.name = "watchdog",
	202	.fops = &mtx1_wdt_fops,
04bf3b4f FF	203	};
	204
	205
2d991a16	206	static int mtx1_wdt_probe(struct platform_device *pdev)
04bf3b4f FF	207	{
	208	int ret;
	209
6ea8115b	210	mtx1_wdt_device.gpio = pdev->resource[0].start;
d3a33a95	211	ret = devm_gpio_request_one(&pdev->dev, mtx1_wdt_device.gpio,
9b19d40a FF	212	GPIOF_OUT_INIT_HIGH, "mtx1-wdt");
	213	if (ret < 0) {
	214	dev_err(&pdev->dev, "failed to request gpio");
	215	return ret;
	216	}
6ea8115b	217
ed78c2da	218	spin_lock_init(&mtx1_wdt_device.lock);
04bf3b4f FF	219	init_completion(&mtx1_wdt_device.stop);
04bf3b4f FF	220	mtx1_wdt_device.queue = 0;
04bf3b4f	221	clear_bit(0, &mtx1_wdt_device.inuse);
e99e88a9	222	timer_setup(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0);
04bf3b4f FF	223	mtx1_wdt_device.default_ticks = ticks;
04bf3b4f FF	224
ed78c2da AC	225	ret = misc_register(&mtx1_wdt_misc);
ed78c2da AC	226	if (ret < 0) {
fad0a9dd	227	dev_err(&pdev->dev, "failed to register\n");
ed78c2da AC	228	return ret;
ed78c2da AC	229	}
04bf3b4f	230	mtx1_wdt_start();
fad0a9dd	231	dev_info(&pdev->dev, "MTX-1 Watchdog driver\n");
04bf3b4f FF	232	return 0;
	233	}
	234
4b12b896	235	static int mtx1_wdt_remove(struct platform_device *pdev)
04bf3b4f	236	{
ed78c2da	237	/* FIXME: do we need to lock this test ? */
04bf3b4f FF	238	if (mtx1_wdt_device.queue) {
	239	mtx1_wdt_device.queue = 0;
	240	wait_for_completion(&mtx1_wdt_device.stop);
	241	}
9b19d40a	242
04bf3b4f	243	misc_deregister(&mtx1_wdt_misc);
6ea8115b FF	244	return 0;
	245	}
	246
db98f89a	247	static struct platform_driver mtx1_wdt_driver = {
6ea8115b	248	.probe = mtx1_wdt_probe,
82268714	249	.remove = mtx1_wdt_remove,
6ea8115b	250	.driver.name = "mtx1-wdt",
f37d193c	251	.driver.owner = THIS_MODULE,
6ea8115b FF	252	};
6ea8115b FF	253
b8ec6118	254	module_platform_driver(mtx1_wdt_driver);
04bf3b4f FF	255
	256	MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
	257	MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
	258	MODULE_LICENSE("GPL");
f37d193c	259	MODULE_ALIAS("platform:mtx1-wdt");