Commit | Line | Data |
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90074dce | 1 | /* |
2 | * Watchdog driver for Broadcom BCM47XX | |
3 | * | |
4 | * Copyright (C) 2008 Aleksandar Radovanovic <biblbroks@sezampro.rs> | |
5 | * Copyright (C) 2009 Matthieu CASTET <castet.matthieu@free.fr> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | */ | |
12 | ||
13 | #include <linux/bitops.h> | |
14 | #include <linux/errno.h> | |
15 | #include <linux/fs.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/miscdevice.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/moduleparam.h> | |
21 | #include <linux/reboot.h> | |
22 | #include <linux/types.h> | |
23 | #include <linux/uaccess.h> | |
24 | #include <linux/watchdog.h> | |
25 | #include <linux/timer.h> | |
26 | #include <linux/jiffies.h> | |
27 | #include <linux/ssb/ssb_embedded.h> | |
28 | #include <asm/mach-bcm47xx/bcm47xx.h> | |
29 | ||
30 | #define DRV_NAME "bcm47xx_wdt" | |
31 | ||
32 | #define WDT_DEFAULT_TIME 30 /* seconds */ | |
33 | #define WDT_MAX_TIME 255 /* seconds */ | |
34 | ||
35 | static int wdt_time = WDT_DEFAULT_TIME; | |
36 | static int nowayout = WATCHDOG_NOWAYOUT; | |
37 | ||
38 | module_param(wdt_time, int, 0); | |
39 | MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default=" | |
40 | __MODULE_STRING(WDT_DEFAULT_TIME) ")"); | |
41 | ||
42 | #ifdef CONFIG_WATCHDOG_NOWAYOUT | |
43 | module_param(nowayout, int, 0); | |
44 | MODULE_PARM_DESC(nowayout, | |
45 | "Watchdog cannot be stopped once started (default=" | |
46 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
47 | #endif | |
48 | ||
49 | static unsigned long bcm47xx_wdt_busy; | |
50 | static char expect_release; | |
51 | static struct timer_list wdt_timer; | |
52 | static atomic_t ticks; | |
53 | ||
54 | static inline void bcm47xx_wdt_hw_start(void) | |
55 | { | |
56 | /* this is 2,5s on 100Mhz clock and 2s on 133 Mhz */ | |
08ccf572 | 57 | switch (bcm47xx_bus_type) { |
a656ffcb | 58 | #ifdef CONFIG_BCM47XX_SSB |
08ccf572 HM |
59 | case BCM47XX_BUS_TYPE_SSB: |
60 | ssb_watchdog_timer_set(&bcm47xx_bus.ssb, 0xfffffff); | |
61 | break; | |
c1d1c5d4 HM |
62 | #endif |
63 | #ifdef CONFIG_BCM47XX_BCMA | |
64 | case BCM47XX_BUS_TYPE_BCMA: | |
65 | bcma_chipco_watchdog_timer_set(&bcm47xx_bus.bcma.bus.drv_cc, | |
66 | 0xfffffff); | |
67 | break; | |
a656ffcb | 68 | #endif |
08ccf572 | 69 | } |
90074dce | 70 | } |
71 | ||
72 | static inline int bcm47xx_wdt_hw_stop(void) | |
73 | { | |
08ccf572 | 74 | switch (bcm47xx_bus_type) { |
a656ffcb | 75 | #ifdef CONFIG_BCM47XX_SSB |
08ccf572 HM |
76 | case BCM47XX_BUS_TYPE_SSB: |
77 | return ssb_watchdog_timer_set(&bcm47xx_bus.ssb, 0); | |
c1d1c5d4 HM |
78 | #endif |
79 | #ifdef CONFIG_BCM47XX_BCMA | |
80 | case BCM47XX_BUS_TYPE_BCMA: | |
81 | bcma_chipco_watchdog_timer_set(&bcm47xx_bus.bcma.bus.drv_cc, 0); | |
82 | return 0; | |
a656ffcb | 83 | #endif |
08ccf572 HM |
84 | } |
85 | return -EINVAL; | |
90074dce | 86 | } |
87 | ||
88 | static void bcm47xx_timer_tick(unsigned long unused) | |
89 | { | |
90 | if (!atomic_dec_and_test(&ticks)) { | |
91 | bcm47xx_wdt_hw_start(); | |
92 | mod_timer(&wdt_timer, jiffies + HZ); | |
93 | } else { | |
94 | printk(KERN_CRIT DRV_NAME "Watchdog will fire soon!!!\n"); | |
95 | } | |
96 | } | |
97 | ||
98 | static inline void bcm47xx_wdt_pet(void) | |
99 | { | |
100 | atomic_set(&ticks, wdt_time); | |
101 | } | |
102 | ||
103 | static void bcm47xx_wdt_start(void) | |
104 | { | |
105 | bcm47xx_wdt_pet(); | |
106 | bcm47xx_timer_tick(0); | |
107 | } | |
108 | ||
109 | static void bcm47xx_wdt_pause(void) | |
110 | { | |
111 | del_timer_sync(&wdt_timer); | |
112 | bcm47xx_wdt_hw_stop(); | |
113 | } | |
114 | ||
115 | static void bcm47xx_wdt_stop(void) | |
116 | { | |
117 | bcm47xx_wdt_pause(); | |
118 | } | |
119 | ||
120 | static int bcm47xx_wdt_settimeout(int new_time) | |
121 | { | |
122 | if ((new_time <= 0) || (new_time > WDT_MAX_TIME)) | |
123 | return -EINVAL; | |
124 | ||
125 | wdt_time = new_time; | |
126 | return 0; | |
127 | } | |
128 | ||
129 | static int bcm47xx_wdt_open(struct inode *inode, struct file *file) | |
130 | { | |
131 | if (test_and_set_bit(0, &bcm47xx_wdt_busy)) | |
132 | return -EBUSY; | |
133 | ||
134 | bcm47xx_wdt_start(); | |
135 | return nonseekable_open(inode, file); | |
136 | } | |
137 | ||
138 | static int bcm47xx_wdt_release(struct inode *inode, struct file *file) | |
139 | { | |
140 | if (expect_release == 42) { | |
141 | bcm47xx_wdt_stop(); | |
142 | } else { | |
143 | printk(KERN_CRIT DRV_NAME | |
144 | ": Unexpected close, not stopping watchdog!\n"); | |
145 | bcm47xx_wdt_start(); | |
146 | } | |
147 | ||
148 | clear_bit(0, &bcm47xx_wdt_busy); | |
149 | expect_release = 0; | |
150 | return 0; | |
151 | } | |
152 | ||
153 | static ssize_t bcm47xx_wdt_write(struct file *file, const char __user *data, | |
154 | size_t len, loff_t *ppos) | |
155 | { | |
156 | if (len) { | |
157 | if (!nowayout) { | |
158 | size_t i; | |
159 | ||
160 | expect_release = 0; | |
161 | ||
162 | for (i = 0; i != len; i++) { | |
163 | char c; | |
164 | if (get_user(c, data + i)) | |
165 | return -EFAULT; | |
166 | if (c == 'V') | |
167 | expect_release = 42; | |
168 | } | |
169 | } | |
170 | bcm47xx_wdt_pet(); | |
171 | } | |
172 | return len; | |
173 | } | |
174 | ||
42747d71 | 175 | static const struct watchdog_info bcm47xx_wdt_info = { |
5f3b2756 WVS |
176 | .identity = DRV_NAME, |
177 | .options = WDIOF_SETTIMEOUT | | |
90074dce | 178 | WDIOF_KEEPALIVEPING | |
179 | WDIOF_MAGICCLOSE, | |
180 | }; | |
181 | ||
182 | static long bcm47xx_wdt_ioctl(struct file *file, | |
183 | unsigned int cmd, unsigned long arg) | |
184 | { | |
185 | void __user *argp = (void __user *)arg; | |
186 | int __user *p = argp; | |
b86a6c6c | 187 | int new_value, retval = -EINVAL; |
90074dce | 188 | |
189 | switch (cmd) { | |
190 | case WDIOC_GETSUPPORT: | |
191 | return copy_to_user(argp, &bcm47xx_wdt_info, | |
192 | sizeof(bcm47xx_wdt_info)) ? -EFAULT : 0; | |
193 | ||
194 | case WDIOC_GETSTATUS: | |
195 | case WDIOC_GETBOOTSTATUS: | |
196 | return put_user(0, p); | |
197 | ||
198 | case WDIOC_SETOPTIONS: | |
199 | if (get_user(new_value, p)) | |
200 | return -EFAULT; | |
201 | ||
202 | if (new_value & WDIOS_DISABLECARD) { | |
203 | bcm47xx_wdt_stop(); | |
204 | retval = 0; | |
205 | } | |
206 | ||
207 | if (new_value & WDIOS_ENABLECARD) { | |
208 | bcm47xx_wdt_start(); | |
209 | retval = 0; | |
210 | } | |
211 | ||
212 | return retval; | |
213 | ||
214 | case WDIOC_KEEPALIVE: | |
215 | bcm47xx_wdt_pet(); | |
216 | return 0; | |
217 | ||
218 | case WDIOC_SETTIMEOUT: | |
219 | if (get_user(new_value, p)) | |
220 | return -EFAULT; | |
221 | ||
222 | if (bcm47xx_wdt_settimeout(new_value)) | |
223 | return -EINVAL; | |
224 | ||
225 | bcm47xx_wdt_pet(); | |
226 | ||
227 | case WDIOC_GETTIMEOUT: | |
228 | return put_user(wdt_time, p); | |
229 | ||
230 | default: | |
231 | return -ENOTTY; | |
232 | } | |
233 | } | |
234 | ||
235 | static int bcm47xx_wdt_notify_sys(struct notifier_block *this, | |
236 | unsigned long code, void *unused) | |
237 | { | |
238 | if (code == SYS_DOWN || code == SYS_HALT) | |
239 | bcm47xx_wdt_stop(); | |
240 | return NOTIFY_DONE; | |
241 | } | |
242 | ||
243 | static const struct file_operations bcm47xx_wdt_fops = { | |
244 | .owner = THIS_MODULE, | |
245 | .llseek = no_llseek, | |
246 | .unlocked_ioctl = bcm47xx_wdt_ioctl, | |
247 | .open = bcm47xx_wdt_open, | |
248 | .release = bcm47xx_wdt_release, | |
249 | .write = bcm47xx_wdt_write, | |
250 | }; | |
251 | ||
252 | static struct miscdevice bcm47xx_wdt_miscdev = { | |
253 | .minor = WATCHDOG_MINOR, | |
254 | .name = "watchdog", | |
255 | .fops = &bcm47xx_wdt_fops, | |
256 | }; | |
257 | ||
258 | static struct notifier_block bcm47xx_wdt_notifier = { | |
259 | .notifier_call = bcm47xx_wdt_notify_sys, | |
260 | }; | |
261 | ||
262 | static int __init bcm47xx_wdt_init(void) | |
263 | { | |
264 | int ret; | |
265 | ||
266 | if (bcm47xx_wdt_hw_stop() < 0) | |
267 | return -ENODEV; | |
268 | ||
269 | setup_timer(&wdt_timer, bcm47xx_timer_tick, 0L); | |
270 | ||
271 | if (bcm47xx_wdt_settimeout(wdt_time)) { | |
272 | bcm47xx_wdt_settimeout(WDT_DEFAULT_TIME); | |
273 | printk(KERN_INFO DRV_NAME ": " | |
274 | "wdt_time value must be 0 < wdt_time < %d, using %d\n", | |
275 | (WDT_MAX_TIME + 1), wdt_time); | |
276 | } | |
277 | ||
278 | ret = register_reboot_notifier(&bcm47xx_wdt_notifier); | |
279 | if (ret) | |
280 | return ret; | |
281 | ||
282 | ret = misc_register(&bcm47xx_wdt_miscdev); | |
283 | if (ret) { | |
284 | unregister_reboot_notifier(&bcm47xx_wdt_notifier); | |
285 | return ret; | |
286 | } | |
287 | ||
288 | printk(KERN_INFO "BCM47xx Watchdog Timer enabled (%d seconds%s)\n", | |
289 | wdt_time, nowayout ? ", nowayout" : ""); | |
290 | return 0; | |
291 | } | |
292 | ||
293 | static void __exit bcm47xx_wdt_exit(void) | |
294 | { | |
295 | if (!nowayout) | |
296 | bcm47xx_wdt_stop(); | |
297 | ||
298 | misc_deregister(&bcm47xx_wdt_miscdev); | |
299 | ||
300 | unregister_reboot_notifier(&bcm47xx_wdt_notifier); | |
301 | } | |
302 | ||
303 | module_init(bcm47xx_wdt_init); | |
304 | module_exit(bcm47xx_wdt_exit); | |
305 | ||
306 | MODULE_AUTHOR("Aleksandar Radovanovic"); | |
307 | MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx"); | |
308 | MODULE_LICENSE("GPL"); | |
309 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |