2 * Driver for the MTX-1 Watchdog.
4 * (C) Copyright 2005 4G Systems <info@4g-systems.biz>,
6 * http://www.4g-systems.biz
8 * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
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.
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.
19 * (c) Copyright 2005 4G Systems <info@4g-systems.biz>
22 * Author: Michael Stickel michael.stickel@4g-systems.biz
25 * Author: Florian Fainelli florian@openwrt.org
26 * use the Linux watchdog/timer APIs
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.
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.
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>
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>
49 #include <linux/platform_device.h>
51 #include <linux/uaccess.h>
52 #include <linux/gpio.h>
54 #include <asm/mach-au1x00/au1000.h>
56 #define MTX1_WDT_INTERVAL (5 * HZ)
58 static int ticks = 100 * HZ;
61 struct completion stop;
64 struct timer_list timer;
72 static void mtx1_wdt_trigger(unsigned long unused)
76 spin_lock(&mtx1_wdt_device.lock);
77 if (mtx1_wdt_device.running)
81 mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate;
82 gpio_set_value(mtx1_wdt_device.gpio, mtx1_wdt_device.gstate);
84 if (mtx1_wdt_device.queue && ticks)
85 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
87 complete(&mtx1_wdt_device.stop);
88 spin_unlock(&mtx1_wdt_device.lock);
91 static void mtx1_wdt_reset(void)
93 ticks = mtx1_wdt_device.default_ticks;
97 static void mtx1_wdt_start(void)
101 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
102 if (!mtx1_wdt_device.queue) {
103 mtx1_wdt_device.queue = 1;
104 mtx1_wdt_device.gstate = 1;
105 gpio_set_value(mtx1_wdt_device.gpio, 1);
106 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
108 mtx1_wdt_device.running++;
109 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
112 static int mtx1_wdt_stop(void)
116 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
117 if (mtx1_wdt_device.queue) {
118 mtx1_wdt_device.queue = 0;
119 mtx1_wdt_device.gstate = 0;
120 gpio_set_value(mtx1_wdt_device.gpio, 0);
122 ticks = mtx1_wdt_device.default_ticks;
123 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
127 /* Filesystem functions */
129 static int mtx1_wdt_open(struct inode *inode, struct file *file)
131 if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
133 return nonseekable_open(inode, file);
137 static int mtx1_wdt_release(struct inode *inode, struct file *file)
139 clear_bit(0, &mtx1_wdt_device.inuse);
143 static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
146 void __user *argp = (void __user *)arg;
147 int __user *p = (int __user *)argp;
149 static const struct watchdog_info ident = {
150 .options = WDIOF_CARDRESET,
151 .identity = "MTX-1 WDT",
155 case WDIOC_GETSUPPORT:
156 if (copy_to_user(argp, &ident, sizeof(ident)))
159 case WDIOC_GETSTATUS:
160 case WDIOC_GETBOOTSTATUS:
163 case WDIOC_SETOPTIONS:
164 if (get_user(value, p))
166 if (value & WDIOS_ENABLECARD)
168 else if (value & WDIOS_DISABLECARD)
173 case WDIOC_KEEPALIVE:
183 static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
184 size_t count, loff_t *ppos)
192 static const struct file_operations mtx1_wdt_fops = {
193 .owner = THIS_MODULE,
195 .unlocked_ioctl = mtx1_wdt_ioctl,
196 .open = mtx1_wdt_open,
197 .write = mtx1_wdt_write,
198 .release = mtx1_wdt_release,
202 static struct miscdevice mtx1_wdt_misc = {
203 .minor = WATCHDOG_MINOR,
205 .fops = &mtx1_wdt_fops,
209 static int __devinit mtx1_wdt_probe(struct platform_device *pdev)
213 mtx1_wdt_device.gpio = pdev->resource[0].start;
214 ret = gpio_request_one(mtx1_wdt_device.gpio,
215 GPIOF_OUT_INIT_HIGH, "mtx1-wdt");
217 dev_err(&pdev->dev, "failed to request gpio");
221 spin_lock_init(&mtx1_wdt_device.lock);
222 init_completion(&mtx1_wdt_device.stop);
223 mtx1_wdt_device.queue = 0;
224 clear_bit(0, &mtx1_wdt_device.inuse);
225 setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
226 mtx1_wdt_device.default_ticks = ticks;
228 ret = misc_register(&mtx1_wdt_misc);
230 printk(KERN_ERR " mtx-1_wdt : failed to register\n");
234 printk(KERN_INFO "MTX-1 Watchdog driver\n");
238 static int __devexit mtx1_wdt_remove(struct platform_device *pdev)
240 /* FIXME: do we need to lock this test ? */
241 if (mtx1_wdt_device.queue) {
242 mtx1_wdt_device.queue = 0;
243 wait_for_completion(&mtx1_wdt_device.stop);
246 gpio_free(mtx1_wdt_device.gpio);
247 misc_deregister(&mtx1_wdt_misc);
251 static struct platform_driver mtx1_wdt = {
252 .probe = mtx1_wdt_probe,
253 .remove = __devexit_p(mtx1_wdt_remove),
254 .driver.name = "mtx1-wdt",
255 .driver.owner = THIS_MODULE,
258 static int __init mtx1_wdt_init(void)
260 return platform_driver_register(&mtx1_wdt);
263 static void __exit mtx1_wdt_exit(void)
265 platform_driver_unregister(&mtx1_wdt);
268 module_init(mtx1_wdt_init);
269 module_exit(mtx1_wdt_exit);
271 MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
272 MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
273 MODULE_LICENSE("GPL");
274 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
275 MODULE_ALIAS("platform:mtx1-wdt");