[deliverable/linux.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 <asm/io.h>
#include <asm/uaccess.h>

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

#define MTX1_WDT_INTERVAL	(5 * HZ)

static int ticks = 100 * HZ;

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

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

	if (mtx1_wdt_device.running)
		ticks--;
	/*
	 * toggle GPIO2_15
	 */
	tmp = au_readl(GPIO2_DIR);
	tmp = (tmp & ~(1<<15)) | ((~tmp) & (1<<15));
	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);
	}
}

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


static void mtx1_wdt_start(void)
{
	if (!mtx1_wdt_device.queue) {
		mtx1_wdt_device.queue = 1;
		au_writel (au_readl(GPIO2_DIR) | (u32)(1<<15), GPIO2_DIR);
		mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
	}
	mtx1_wdt_device.running++;
}

static int mtx1_wdt_stop(void)
{
	if (mtx1_wdt_device.queue) {
		mtx1_wdt_device.queue = 0;
		au_writel (au_readl(GPIO2_DIR) & ~((u32)(1<<15)), GPIO2_DIR);
	}

	ticks = mtx1_wdt_device.default_ticks;

	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 int mtx1_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	unsigned int value;
	static 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:
			if ( copy_to_user(argp, &value, sizeof(int)) )
				return -EFAULT;
			break;
		case WDIOC_GETSUPPORT:
			if ( copy_to_user(argp, &ident, sizeof(ident)) )
				return -EFAULT;
			break;
		case WDIOC_SETOPTIONS:
			if ( copy_from_user(&value, argp, sizeof(int)) )
				return -EFAULT;
			switch(value) {
				case WDIOS_ENABLECARD:
					mtx1_wdt_start();
					break;
				case WDIOS_DISABLECARD:
					return mtx1_wdt_stop();
				default:
					return -EINVAL;
			}
			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,
	.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 __init mtx1_wdt_init(void)
{
	int ret;

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

	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;

	mtx1_wdt_start();

	printk(KERN_INFO "MTX-1 Watchdog driver\n");

	return 0;
}

static void __exit mtx1_wdt_exit(void)
{
	if (mtx1_wdt_device.queue) {
		mtx1_wdt_device.queue = 0;
		wait_for_completion(&mtx1_wdt_device.stop);
	}
	misc_deregister(&mtx1_wdt_misc);
}

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");
Commit	Line	Data
04bf3b4f FF	1	/*
	2	* Driver for the MTX-1 Watchdog.
	3	*
	4	* (C) Copyright 2005 4G Systems <info@4g-systems.biz>, All Rights Reserved.
	5	* http://www.4g-systems.biz
	6	*
	7	* (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*
	14	* Neither Michael Stickel nor 4G Systems admit liability nor provide
	15	* warranty for any of this software. This material is provided
	16	* "AS-IS" and at no charge.
	17	*
	18	* (c) Copyright 2005 4G Systems <info@4g-systems.biz>
	19	*
	20	* Release 0.01.
	21	* Author: Michael Stickel michael.stickel@4g-systems.biz
	22	*
	23	* Release 0.02.
	24	* Author: Florian Fainelli florian@openwrt.org
	25	* use the Linux watchdog/timer APIs
	26	*
	27	* The Watchdog is configured to reset the MTX-1
	28	* if it is not triggered for 100 seconds.
	29	* It should not be triggered more often than 1.6 seconds.
	30	*
	31	* A timer triggers the watchdog every 5 seconds, until
	32	* it is opened for the first time. After the first open
	33	* it MUST be triggered every 2..95 seconds.
	34	*/
	35
	36	#include <linux/module.h>
	37	#include <linux/moduleparam.h>
	38	#include <linux/types.h>
	39	#include <linux/errno.h>
	40	#include <linux/miscdevice.h>
	41	#include <linux/fs.h>
	42	#include <linux/init.h>
	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>
	48	#include <asm/io.h>
	49	#include <asm/uaccess.h>
	50
	51	#include <asm/mach-au1x00/au1000.h>
	52
	53	#define MTX1_WDT_INTERVAL (5 * HZ)
	54
	55	static int ticks = 100 * HZ;
	56
	57	static struct {
	58	struct completion stop;
	59	volatile int running;
	60	struct timer_list timer;
	61	volatile int queue;
	62	int default_ticks;
	63	unsigned long inuse;
	64	} mtx1_wdt_device;
65
66	static void mtx1_wdt_trigger(unsigned long unused)
67	{
68	u32 tmp;
69
70	if (mtx1_wdt_device.running)
71	ticks--;
72	/*
73	* toggle GPIO2_15
74	*/
75	tmp = au_readl(GPIO2_DIR);
76	tmp = (tmp & ~(1<<15)) \| ((~tmp) & (1<<15));
77	au_writel (tmp, GPIO2_DIR);
78
79	if (mtx1_wdt_device.queue && ticks)
80	mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
81	else {
82	complete(&mtx1_wdt_device.stop);
83	}
84	}
85
86	static void mtx1_wdt_reset(void)
87	{
88	ticks = mtx1_wdt_device.default_ticks;
89	}
90
91
92	static void mtx1_wdt_start(void)
93	{
94	if (!mtx1_wdt_device.queue) {
95	mtx1_wdt_device.queue = 1;
96	au_writel (au_readl(GPIO2_DIR) \| (u32)(1<<15), GPIO2_DIR);
97	mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
98	}
99	mtx1_wdt_device.running++;
100	}
101
102	static int mtx1_wdt_stop(void)
103	{
104	if (mtx1_wdt_device.queue) {
105	mtx1_wdt_device.queue = 0;
106	au_writel (au_readl(GPIO2_DIR) & ~((u32)(1<<15)), GPIO2_DIR);
107	}
108
109	ticks = mtx1_wdt_device.default_ticks;
110
111	return 0;
112	}
113
114	/* Filesystem functions */
115
116	static int mtx1_wdt_open(struct inode inode, struct file file)
117	{
118	if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
119	return -EBUSY;
120
121	return nonseekable_open(inode, file);
122	}
123
124
125	static int mtx1_wdt_release(struct inode inode, struct file file)
126	{
127	clear_bit(0, &mtx1_wdt_device.inuse);
128	return 0;
129	}
130
131	static int mtx1_wdt_ioctl(struct inode inode, struct file file, unsigned int cmd, unsigned long arg)
132	{
133	void __user argp = (void __user )arg;
134	unsigned int value;
135	static struct watchdog_info ident =
136	{
137	.options = WDIOF_CARDRESET,
138	.identity = "MTX-1 WDT",
139	};
140
141	switch(cmd) {
142	case WDIOC_KEEPALIVE:
143	mtx1_wdt_reset();
144	break;
145	case WDIOC_GETSTATUS:
5c4eb61b	146	case WDIOC_GETBOOTSTATUS:
04bf3b4f FF	147	if ( copy_to_user(argp, &value, sizeof(int)) )
	148	return -EFAULT;
	149	break;
	150	case WDIOC_GETSUPPORT:
	151	if ( copy_to_user(argp, &ident, sizeof(ident)) )
	152	return -EFAULT;
	153	break;
	154	case WDIOC_SETOPTIONS:
	155	if ( copy_from_user(&value, argp, sizeof(int)) )
	156	return -EFAULT;
	157	switch(value) {
	158	case WDIOS_ENABLECARD:
	159	mtx1_wdt_start();
	160	break;
	161	case WDIOS_DISABLECARD:
	162	return mtx1_wdt_stop();
	163	default:
	164	return -EINVAL;
	165	}
	166	break;
	167	default:
	168	return -ENOTTY;
	169	}
	170	return 0;
	171	}
	172
	173
	174	static ssize_t mtx1_wdt_write(struct file file, const char buf, size_t count, loff_t *ppos)
	175	{
	176	if (!count)
	177	return -EIO;
	178
	179	mtx1_wdt_reset();
	180	return count;
	181	}
	182
b47a166e	183	static const struct file_operations mtx1_wdt_fops = {
04bf3b4f FF	184	.owner = THIS_MODULE,
	185	.llseek = no_llseek,
	186	.ioctl = mtx1_wdt_ioctl,
	187	.open = mtx1_wdt_open,
	188	.write = mtx1_wdt_write,
	189	.release = mtx1_wdt_release
	190	};
	191
	192
	193	static struct miscdevice mtx1_wdt_misc = {
	194	.minor = WATCHDOG_MINOR,
	195	.name = "watchdog",
	196	.fops = &mtx1_wdt_fops
	197	};
	198
	199
	200	static int __init mtx1_wdt_init(void)
	201	{
	202	int ret;
	203
	204	if ((ret = misc_register(&mtx1_wdt_misc)) < 0) {
	205	printk(KERN_ERR " mtx-1_wdt : failed to register\n");
	206	return ret;
	207	}
	208
	209	init_completion(&mtx1_wdt_device.stop);
	210	mtx1_wdt_device.queue = 0;
	211
	212	clear_bit(0, &mtx1_wdt_device.inuse);
	213
	214	setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
	215
	216	mtx1_wdt_device.default_ticks = ticks;
	217
	218	mtx1_wdt_start();
	219
	220	printk(KERN_INFO "MTX-1 Watchdog driver\n");
	221
	222	return 0;
	223	}
	224
	225	static void __exit mtx1_wdt_exit(void)
	226	{
	227	if (mtx1_wdt_device.queue) {
	228	mtx1_wdt_device.queue = 0;
	229	wait_for_completion(&mtx1_wdt_device.stop);
	230	}
	231	misc_deregister(&mtx1_wdt_misc);
	232	}
	233
	234	module_init(mtx1_wdt_init);
	235	module_exit(mtx1_wdt_exit);
	236
	237	MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
	238	MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
	239	MODULE_LICENSE("GPL");