2 * RC32434_WDT 0.01: IDT Interprise 79RC32434 watchdog driver
3 * Copyright (c) Ondrej Zajicek <santiago@crfreenet.org>, 2006
7 * SoftDog 0.05: A Software Watchdog Device
9 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
18 #include <linux/module.h>
19 #include <linux/types.h>
20 #include <linux/kernel.h>
23 #include <linux/miscdevice.h>
24 #include <linux/watchdog.h>
25 #include <linux/reboot.h>
26 #include <linux/smp_lock.h>
27 #include <linux/init.h>
28 #include <asm/bootinfo.h>
30 #include <asm/uaccess.h>
31 #include <asm/rc32434/integ.h>
33 #define DEFAULT_TIMEOUT 15 /* (secs) Default is 15 seconds */
34 #define MAX_TIMEOUT 20
36 * (secs) Max is 20 seconds
37 * (max frequency of counter is ~200 MHz, counter is 32-bit unsigned int)
40 #define NAME "rc32434_wdt"
43 static INTEG_t rc_wdt = (INTEG_t) INTEG_VirtualAddress;
45 static int expect_close = 0;
46 static int access = 0;
47 static int timeout = 0;
49 static int nowayout = WATCHDOG_NOWAYOUT;
50 module_param(nowayout, int, 0);
51 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
52 MODULE_LICENSE("GPL");
55 static inline void start_wdt(void)
57 rc_wdt -> wtcount = 0;
58 rc_wdt -> errcs |= ERRCS_wre_m;
59 rc_wdt -> wtc |= WTC_en_m;
62 static inline void stop_wdt(void)
64 rc_wdt -> wtc &= ~WTC_en_m;
65 rc_wdt -> errcs &= ~ERRCS_wre_m;
68 static inline void set_wdt(int new_timeout)
70 u32 cmp = new_timeout * mips_hpt_frequency;
73 timeout = new_timeout;
75 * store and disable WTC
77 state = rc_wdt -> wtc & WTC_en_m;
78 rc_wdt -> wtc &= ~WTC_en_m;
80 rc_wdt -> wtcount = 0;
81 rc_wdt -> wtcompare = cmp;
86 rc_wdt -> wtc |= state;
89 static inline void update_wdt(void)
91 rc_wdt -> wtcount = 0;
95 * Allow only one person to hold it open
98 static int wdt_open(struct inode *inode, struct file *file)
103 __module_get(THIS_MODULE);
109 printk(KERN_INFO NAME ": enabling watchdog timer\n");
114 static int wdt_release(struct inode *inode, struct file *file)
117 * Shut off the timer.
118 * Lock it in if it's a module and we set nowayout
120 if (expect_close && nowayout == 0) {
122 printk(KERN_INFO NAME ": disabling watchdog timer\n");
123 module_put(THIS_MODULE);
125 printk (KERN_CRIT NAME ": device closed unexpectedly. WDT will not stop!\n");
131 static ssize_t wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
140 /* In case it was set long ago */
143 for (i = 0; i != len; i++) {
145 if (get_user(c, data + i))
157 static int wdt_ioctl(struct inode *inode, struct file *file,
158 unsigned int cmd, unsigned long arg)
161 static struct watchdog_info ident = {
162 .options = WDIOF_SETTIMEOUT |
163 WDIOF_KEEPALIVEPING |
165 .firmware_version = 0,
166 .identity = "RC32434_WDT Watchdog",
171 case WDIOC_GETSUPPORT:
172 if(copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)))
175 case WDIOC_GETSTATUS:
176 case WDIOC_GETBOOTSTATUS:
177 return put_user(0,(int *)arg);
178 case WDIOC_KEEPALIVE:
181 case WDIOC_SETTIMEOUT:
182 if (get_user(new_timeout, (int *)arg))
186 if (new_timeout > MAX_TIMEOUT)
188 set_wdt(new_timeout);
190 case WDIOC_GETTIMEOUT:
191 return put_user(timeout, (int *)arg);
195 static struct file_operations wdt_fops = {
201 release: wdt_release,
204 static struct miscdevice wdt_miscdev = {
205 minor: WATCHDOG_MINOR,
210 static char banner[] __initdata = KERN_INFO NAME ": Watchdog Timer version " VERSION ", timer margin: %d sec\n";
212 static int __init watchdog_init(void)
217 * There should be check for RC32434 SoC
219 if (mips_machgroup != MACH_GROUP_MIKROTIK) return -1;
221 ret = misc_register(&wdt_miscdev);
227 set_wdt(DEFAULT_TIMEOUT);
229 printk(banner, timeout);
234 static void __exit watchdog_exit(void)
236 misc_deregister(&wdt_miscdev);
239 module_init(watchdog_init);
240 module_exit(watchdog_exit);