2 * RDC321x watchdog driver
4 * Copyright (C) 2007 Florian Fainelli <florian@openwrt.org>
6 * This driver is highly inspired from the cpu5_wdt driver
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/types.h>
27 #include <linux/errno.h>
28 #include <linux/miscdevice.h>
30 #include <linux/init.h>
31 #include <linux/ioport.h>
32 #include <linux/timer.h>
33 #include <linux/completion.h>
34 #include <linux/jiffies.h>
35 #include <linux/platform_device.h>
36 #include <linux/watchdog.h>
39 #include <asm/uaccess.h>
41 #include <asm/mach-rdc/rdc321x_defs.h>
43 #define RDC_WDT_MASK 0x80000000 /* Mask */
44 #define RDC_WDT_EN 0x00800000 /* Enable bit */
45 #define RDC_WDT_WTI 0x00200000 /* Generate a CPU reset/NMI/WDT irq when WDT timeout is reached */
46 #define RDC_WDT_RST 0x00100000 /* Reset bit */
47 #define RDC_WDT_WIF 0x00040000 /* WDT IRQ Flag */
48 #define RDC_WDT_IRT 0x00000100 /* IRQ Routing table */
49 #define RDC_WDT_CNT 0x00000001 /* WDT count */
51 #define RDC_CLS_TMR 0x80003844 /* Clear timer */
53 #define RDC_WDT_INTERVAL (HZ/10+1)
55 int nowayout = WATCHDOG_NOWAYOUT;
56 module_param(nowayout, int, 0);
57 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
59 static int ticks = 1000;
61 /* some device data */
64 struct completion stop;
66 struct timer_list timer;
72 /* generic helper functions */
74 static void rdc321x_wdt_trigger(unsigned long unused)
76 if( rdc321x_wdt_device.running )
79 /* keep watchdog alive */
80 outl(RDC_WDT_EN|inl(RDC3210_CFGREG_DATA), RDC3210_CFGREG_DATA);
83 if (rdc321x_wdt_device.queue && ticks)
84 mod_timer(&rdc321x_wdt_device.timer, jiffies + RDC_WDT_INTERVAL);
86 /* ticks doesn't matter anyway */
87 complete(&rdc321x_wdt_device.stop);
92 static void rdc321x_wdt_reset(void)
94 ticks = rdc321x_wdt_device.default_ticks;
97 static void rdc321x_wdt_start(void)
99 if (!rdc321x_wdt_device.queue) {
100 rdc321x_wdt_device.queue = 1;
102 /* Clear the timer */
103 outl(RDC_CLS_TMR, RDC3210_CFGREG_ADDR);
105 /* Enable watchdog and set the timeout to 81.92 us */
106 outl(RDC_WDT_EN|RDC_WDT_CNT, RDC3210_CFGREG_DATA);
108 mod_timer(&rdc321x_wdt_device.timer, jiffies + RDC_WDT_INTERVAL);
111 /* if process dies, counter is not decremented */
112 rdc321x_wdt_device.running++;
115 static int rdc321x_wdt_stop(void)
117 if (rdc321x_wdt_device.running)
118 rdc321x_wdt_device.running = 0;
120 ticks = rdc321x_wdt_device.default_ticks;
125 /* filesystem operations */
127 static int rdc321x_wdt_open(struct inode *inode, struct file *file)
129 if (test_and_set_bit(0, &rdc321x_wdt_device.inuse))
132 return nonseekable_open(inode, file);
135 static int rdc321x_wdt_release(struct inode *inode, struct file *file)
137 clear_bit(0, &rdc321x_wdt_device.inuse);
141 static int rdc321x_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
143 void __user *argp = (void __user *)arg;
145 static struct watchdog_info ident =
147 .options = WDIOF_CARDRESET,
148 .identity = "RDC321x WDT",
152 case WDIOC_KEEPALIVE:
155 case WDIOC_GETSTATUS:
156 /* Read the value from the DATA register */
157 value = inl(RDC3210_CFGREG_DATA);
158 if ( copy_to_user(argp, &value, sizeof(int)) )
161 case WDIOC_GETSUPPORT:
162 if ( copy_to_user(argp, &ident, sizeof(ident)) )
165 case WDIOC_SETOPTIONS:
166 if ( copy_from_user(&value, argp, sizeof(int)) )
169 case WDIOS_ENABLECARD:
172 case WDIOS_DISABLECARD:
173 return rdc321x_wdt_stop();
184 static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
194 static const struct file_operations rdc321x_wdt_fops = {
195 .owner = THIS_MODULE,
197 .ioctl = rdc321x_wdt_ioctl,
198 .open = rdc321x_wdt_open,
199 .write = rdc321x_wdt_write,
200 .release = rdc321x_wdt_release,
203 static struct miscdevice rdc321x_wdt_misc = {
204 .minor = WATCHDOG_MINOR,
206 .fops = &rdc321x_wdt_fops,
209 static int __devinit rdc321x_wdt_probe(struct platform_device *pdev)
213 if ( (err = misc_register(&rdc321x_wdt_misc)) < 0 ) {
214 printk(KERN_ERR PFX "misc_register failed\n");
218 /* Reset the watchdog */
219 outl(RDC_WDT_RST, RDC3210_CFGREG_DATA);
221 init_completion(&rdc321x_wdt_device.stop);
222 rdc321x_wdt_device.queue = 0;
224 clear_bit(0, &rdc321x_wdt_device.inuse);
226 setup_timer(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);
228 rdc321x_wdt_device.default_ticks = ticks;
230 printk(KERN_INFO PFX "init success\n");
235 static int rdc321x_wdt_remove(struct platform_device *pdev)
237 if (rdc321x_wdt_device.queue) {
238 rdc321x_wdt_device.queue = 0;
239 wait_for_completion(&rdc321x_wdt_device.stop);
242 misc_deregister(&rdc321x_wdt_misc);
247 static struct platform_driver rdc321x_wdt_driver = {
248 .probe = rdc321x_wdt_probe,
249 .remove = rdc321x_wdt_remove,
251 .owner = THIS_MODULE,
252 .name = "rdc321x-wdt",
256 static int __init rdc321x_wdt_init(void)
258 return platform_driver_register(&rdc321x_wdt_driver);
261 static void __exit rdc321x_wdt_exit(void)
263 platform_driver_unregister(&rdc321x_wdt_driver);
266 module_init(rdc321x_wdt_init);
267 module_exit(rdc321x_wdt_exit);
269 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
270 MODULE_DESCRIPTION("RDC321x watchdog driver");
271 MODULE_LICENSE("GPL");
272 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);