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90074dce MC |
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 | ||
27c766aa JP |
13 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
14 | ||
90074dce MC |
15 | #include <linux/bitops.h> |
16 | #include <linux/errno.h> | |
17 | #include <linux/fs.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/miscdevice.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/moduleparam.h> | |
23 | #include <linux/reboot.h> | |
24 | #include <linux/types.h> | |
25 | #include <linux/uaccess.h> | |
26 | #include <linux/watchdog.h> | |
27 | #include <linux/timer.h> | |
28 | #include <linux/jiffies.h> | |
29 | #include <linux/ssb/ssb_embedded.h> | |
30 | #include <asm/mach-bcm47xx/bcm47xx.h> | |
31 | ||
32 | #define DRV_NAME "bcm47xx_wdt" | |
33 | ||
34 | #define WDT_DEFAULT_TIME 30 /* seconds */ | |
35 | #define WDT_MAX_TIME 255 /* seconds */ | |
36 | ||
37 | static int wdt_time = WDT_DEFAULT_TIME; | |
86a1e189 | 38 | static bool nowayout = WATCHDOG_NOWAYOUT; |
90074dce MC |
39 | |
40 | module_param(wdt_time, int, 0); | |
41 | MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default=" | |
42 | __MODULE_STRING(WDT_DEFAULT_TIME) ")"); | |
43 | ||
44 | #ifdef CONFIG_WATCHDOG_NOWAYOUT | |
86a1e189 | 45 | module_param(nowayout, bool, 0); |
90074dce MC |
46 | MODULE_PARM_DESC(nowayout, |
47 | "Watchdog cannot be stopped once started (default=" | |
48 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
49 | #endif | |
50 | ||
51 | static unsigned long bcm47xx_wdt_busy; | |
52 | static char expect_release; | |
53 | static struct timer_list wdt_timer; | |
54 | static atomic_t ticks; | |
55 | ||
56 | static inline void bcm47xx_wdt_hw_start(void) | |
57 | { | |
58 | /* this is 2,5s on 100Mhz clock and 2s on 133 Mhz */ | |
08ccf572 | 59 | switch (bcm47xx_bus_type) { |
a656ffcb | 60 | #ifdef CONFIG_BCM47XX_SSB |
08ccf572 HM |
61 | case BCM47XX_BUS_TYPE_SSB: |
62 | ssb_watchdog_timer_set(&bcm47xx_bus.ssb, 0xfffffff); | |
63 | break; | |
c1d1c5d4 HM |
64 | #endif |
65 | #ifdef CONFIG_BCM47XX_BCMA | |
66 | case BCM47XX_BUS_TYPE_BCMA: | |
67 | bcma_chipco_watchdog_timer_set(&bcm47xx_bus.bcma.bus.drv_cc, | |
68 | 0xfffffff); | |
69 | break; | |
a656ffcb | 70 | #endif |
08ccf572 | 71 | } |
90074dce MC |
72 | } |
73 | ||
74 | static inline int bcm47xx_wdt_hw_stop(void) | |
75 | { | |
08ccf572 | 76 | switch (bcm47xx_bus_type) { |
a656ffcb | 77 | #ifdef CONFIG_BCM47XX_SSB |
08ccf572 HM |
78 | case BCM47XX_BUS_TYPE_SSB: |
79 | return ssb_watchdog_timer_set(&bcm47xx_bus.ssb, 0); | |
c1d1c5d4 HM |
80 | #endif |
81 | #ifdef CONFIG_BCM47XX_BCMA | |
82 | case BCM47XX_BUS_TYPE_BCMA: | |
83 | bcma_chipco_watchdog_timer_set(&bcm47xx_bus.bcma.bus.drv_cc, 0); | |
84 | return 0; | |
a656ffcb | 85 | #endif |
08ccf572 HM |
86 | } |
87 | return -EINVAL; | |
90074dce MC |
88 | } |
89 | ||
90 | static void bcm47xx_timer_tick(unsigned long unused) | |
91 | { | |
92 | if (!atomic_dec_and_test(&ticks)) { | |
93 | bcm47xx_wdt_hw_start(); | |
94 | mod_timer(&wdt_timer, jiffies + HZ); | |
95 | } else { | |
27c766aa | 96 | pr_crit("Watchdog will fire soon!!!\n"); |
90074dce MC |
97 | } |
98 | } | |
99 | ||
100 | static inline void bcm47xx_wdt_pet(void) | |
101 | { | |
102 | atomic_set(&ticks, wdt_time); | |
103 | } | |
104 | ||
105 | static void bcm47xx_wdt_start(void) | |
106 | { | |
107 | bcm47xx_wdt_pet(); | |
108 | bcm47xx_timer_tick(0); | |
109 | } | |
110 | ||
111 | static void bcm47xx_wdt_pause(void) | |
112 | { | |
113 | del_timer_sync(&wdt_timer); | |
114 | bcm47xx_wdt_hw_stop(); | |
115 | } | |
116 | ||
117 | static void bcm47xx_wdt_stop(void) | |
118 | { | |
119 | bcm47xx_wdt_pause(); | |
120 | } | |
121 | ||
122 | static int bcm47xx_wdt_settimeout(int new_time) | |
123 | { | |
124 | if ((new_time <= 0) || (new_time > WDT_MAX_TIME)) | |
125 | return -EINVAL; | |
126 | ||
127 | wdt_time = new_time; | |
128 | return 0; | |
129 | } | |
130 | ||
131 | static int bcm47xx_wdt_open(struct inode *inode, struct file *file) | |
132 | { | |
133 | if (test_and_set_bit(0, &bcm47xx_wdt_busy)) | |
134 | return -EBUSY; | |
135 | ||
136 | bcm47xx_wdt_start(); | |
137 | return nonseekable_open(inode, file); | |
138 | } | |
139 | ||
140 | static int bcm47xx_wdt_release(struct inode *inode, struct file *file) | |
141 | { | |
142 | if (expect_release == 42) { | |
143 | bcm47xx_wdt_stop(); | |
144 | } else { | |
27c766aa | 145 | pr_crit("Unexpected close, not stopping watchdog!\n"); |
90074dce MC |
146 | bcm47xx_wdt_start(); |
147 | } | |
148 | ||
149 | clear_bit(0, &bcm47xx_wdt_busy); | |
150 | expect_release = 0; | |
151 | return 0; | |
152 | } | |
153 | ||
154 | static ssize_t bcm47xx_wdt_write(struct file *file, const char __user *data, | |
155 | size_t len, loff_t *ppos) | |
156 | { | |
157 | if (len) { | |
158 | if (!nowayout) { | |
159 | size_t i; | |
160 | ||
161 | expect_release = 0; | |
162 | ||
163 | for (i = 0; i != len; i++) { | |
164 | char c; | |
165 | if (get_user(c, data + i)) | |
166 | return -EFAULT; | |
167 | if (c == 'V') | |
168 | expect_release = 42; | |
169 | } | |
170 | } | |
171 | bcm47xx_wdt_pet(); | |
172 | } | |
173 | return len; | |
174 | } | |
175 | ||
42747d71 | 176 | static const struct watchdog_info bcm47xx_wdt_info = { |
5f3b2756 WVS |
177 | .identity = DRV_NAME, |
178 | .options = WDIOF_SETTIMEOUT | | |
90074dce MC |
179 | WDIOF_KEEPALIVEPING | |
180 | WDIOF_MAGICCLOSE, | |
181 | }; | |
182 | ||
183 | static long bcm47xx_wdt_ioctl(struct file *file, | |
184 | unsigned int cmd, unsigned long arg) | |
185 | { | |
186 | void __user *argp = (void __user *)arg; | |
187 | int __user *p = argp; | |
b86a6c6c | 188 | int new_value, retval = -EINVAL; |
90074dce MC |
189 | |
190 | switch (cmd) { | |
191 | case WDIOC_GETSUPPORT: | |
192 | return copy_to_user(argp, &bcm47xx_wdt_info, | |
193 | sizeof(bcm47xx_wdt_info)) ? -EFAULT : 0; | |
194 | ||
195 | case WDIOC_GETSTATUS: | |
196 | case WDIOC_GETBOOTSTATUS: | |
197 | return put_user(0, p); | |
198 | ||
199 | case WDIOC_SETOPTIONS: | |
200 | if (get_user(new_value, p)) | |
201 | return -EFAULT; | |
202 | ||
203 | if (new_value & WDIOS_DISABLECARD) { | |
204 | bcm47xx_wdt_stop(); | |
205 | retval = 0; | |
206 | } | |
207 | ||
208 | if (new_value & WDIOS_ENABLECARD) { | |
209 | bcm47xx_wdt_start(); | |
210 | retval = 0; | |
211 | } | |
212 | ||
213 | return retval; | |
214 | ||
215 | case WDIOC_KEEPALIVE: | |
216 | bcm47xx_wdt_pet(); | |
217 | return 0; | |
218 | ||
219 | case WDIOC_SETTIMEOUT: | |
220 | if (get_user(new_value, p)) | |
221 | return -EFAULT; | |
222 | ||
223 | if (bcm47xx_wdt_settimeout(new_value)) | |
224 | return -EINVAL; | |
225 | ||
226 | bcm47xx_wdt_pet(); | |
227 | ||
228 | case WDIOC_GETTIMEOUT: | |
229 | return put_user(wdt_time, p); | |
230 | ||
231 | default: | |
232 | return -ENOTTY; | |
233 | } | |
234 | } | |
235 | ||
236 | static int bcm47xx_wdt_notify_sys(struct notifier_block *this, | |
237 | unsigned long code, void *unused) | |
238 | { | |
239 | if (code == SYS_DOWN || code == SYS_HALT) | |
240 | bcm47xx_wdt_stop(); | |
241 | return NOTIFY_DONE; | |
242 | } | |
243 | ||
244 | static const struct file_operations bcm47xx_wdt_fops = { | |
245 | .owner = THIS_MODULE, | |
246 | .llseek = no_llseek, | |
247 | .unlocked_ioctl = bcm47xx_wdt_ioctl, | |
248 | .open = bcm47xx_wdt_open, | |
249 | .release = bcm47xx_wdt_release, | |
250 | .write = bcm47xx_wdt_write, | |
251 | }; | |
252 | ||
253 | static struct miscdevice bcm47xx_wdt_miscdev = { | |
254 | .minor = WATCHDOG_MINOR, | |
255 | .name = "watchdog", | |
256 | .fops = &bcm47xx_wdt_fops, | |
257 | }; | |
258 | ||
259 | static struct notifier_block bcm47xx_wdt_notifier = { | |
260 | .notifier_call = bcm47xx_wdt_notify_sys, | |
261 | }; | |
262 | ||
263 | static int __init bcm47xx_wdt_init(void) | |
264 | { | |
265 | int ret; | |
266 | ||
267 | if (bcm47xx_wdt_hw_stop() < 0) | |
268 | return -ENODEV; | |
269 | ||
270 | setup_timer(&wdt_timer, bcm47xx_timer_tick, 0L); | |
271 | ||
272 | if (bcm47xx_wdt_settimeout(wdt_time)) { | |
273 | bcm47xx_wdt_settimeout(WDT_DEFAULT_TIME); | |
27c766aa | 274 | pr_info("wdt_time value must be 0 < wdt_time < %d, using %d\n", |
90074dce MC |
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 | ||
27c766aa JP |
288 | pr_info("BCM47xx Watchdog Timer enabled (%d seconds%s)\n", |
289 | wdt_time, nowayout ? ", nowayout" : ""); | |
90074dce MC |
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); |