Root/
1 | /* Watchdog timer for machines with the CS5535/CS5536 companion chip |
2 | * |
3 | * Copyright (C) 2006-2007, Advanced Micro Devices, Inc. |
4 | * Copyright (C) 2009 Andres Salomon <dilinger@collabora.co.uk> |
5 | * |
6 | * This program is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU General Public License |
8 | * as published by the Free Software Foundation; either version |
9 | * 2 of the License, or (at your option) any later version. |
10 | */ |
11 | |
12 | |
13 | #include <linux/module.h> |
14 | #include <linux/moduleparam.h> |
15 | #include <linux/types.h> |
16 | #include <linux/miscdevice.h> |
17 | #include <linux/watchdog.h> |
18 | #include <linux/fs.h> |
19 | #include <linux/platform_device.h> |
20 | #include <linux/reboot.h> |
21 | #include <linux/uaccess.h> |
22 | |
23 | #include <linux/cs5535.h> |
24 | |
25 | #define GEODEWDT_HZ 500 |
26 | #define GEODEWDT_SCALE 6 |
27 | #define GEODEWDT_MAX_SECONDS 131 |
28 | |
29 | #define WDT_FLAGS_OPEN 1 |
30 | #define WDT_FLAGS_ORPHAN 2 |
31 | |
32 | #define DRV_NAME "geodewdt" |
33 | #define WATCHDOG_NAME "Geode GX/LX WDT" |
34 | #define WATCHDOG_TIMEOUT 60 |
35 | |
36 | static int timeout = WATCHDOG_TIMEOUT; |
37 | module_param(timeout, int, 0); |
38 | MODULE_PARM_DESC(timeout, |
39 | "Watchdog timeout in seconds. 1<= timeout <=131, default=" |
40 | __MODULE_STRING(WATCHDOG_TIMEOUT) "."); |
41 | |
42 | static int nowayout = 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 | |
48 | static struct platform_device *geodewdt_platform_device; |
49 | static unsigned long wdt_flags; |
50 | static struct cs5535_mfgpt_timer *wdt_timer; |
51 | static int safe_close; |
52 | |
53 | static void geodewdt_ping(void) |
54 | { |
55 | /* Stop the counter */ |
56 | cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0); |
57 | |
58 | /* Reset the counter */ |
59 | cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0); |
60 | |
61 | /* Enable the counter */ |
62 | cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN); |
63 | } |
64 | |
65 | static void geodewdt_disable(void) |
66 | { |
67 | cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0); |
68 | cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0); |
69 | } |
70 | |
71 | static int geodewdt_set_heartbeat(int val) |
72 | { |
73 | if (val < 1 || val > GEODEWDT_MAX_SECONDS) |
74 | return -EINVAL; |
75 | |
76 | cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, 0); |
77 | cs5535_mfgpt_write(wdt_timer, MFGPT_REG_CMP2, val * GEODEWDT_HZ); |
78 | cs5535_mfgpt_write(wdt_timer, MFGPT_REG_COUNTER, 0); |
79 | cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN); |
80 | |
81 | timeout = val; |
82 | return 0; |
83 | } |
84 | |
85 | static int geodewdt_open(struct inode *inode, struct file *file) |
86 | { |
87 | if (test_and_set_bit(WDT_FLAGS_OPEN, &wdt_flags)) |
88 | return -EBUSY; |
89 | |
90 | if (!test_and_clear_bit(WDT_FLAGS_ORPHAN, &wdt_flags)) |
91 | __module_get(THIS_MODULE); |
92 | |
93 | geodewdt_ping(); |
94 | return nonseekable_open(inode, file); |
95 | } |
96 | |
97 | static int geodewdt_release(struct inode *inode, struct file *file) |
98 | { |
99 | if (safe_close) { |
100 | geodewdt_disable(); |
101 | module_put(THIS_MODULE); |
102 | } else { |
103 | printk(KERN_CRIT "Unexpected close - watchdog is not stopping.\n"); |
104 | geodewdt_ping(); |
105 | |
106 | set_bit(WDT_FLAGS_ORPHAN, &wdt_flags); |
107 | } |
108 | |
109 | clear_bit(WDT_FLAGS_OPEN, &wdt_flags); |
110 | safe_close = 0; |
111 | return 0; |
112 | } |
113 | |
114 | static ssize_t geodewdt_write(struct file *file, const char __user *data, |
115 | size_t len, loff_t *ppos) |
116 | { |
117 | if (len) { |
118 | if (!nowayout) { |
119 | size_t i; |
120 | safe_close = 0; |
121 | |
122 | for (i = 0; i != len; i++) { |
123 | char c; |
124 | |
125 | if (get_user(c, data + i)) |
126 | return -EFAULT; |
127 | |
128 | if (c == 'V') |
129 | safe_close = 1; |
130 | } |
131 | } |
132 | |
133 | geodewdt_ping(); |
134 | } |
135 | return len; |
136 | } |
137 | |
138 | static long geodewdt_ioctl(struct file *file, unsigned int cmd, |
139 | unsigned long arg) |
140 | { |
141 | void __user *argp = (void __user *)arg; |
142 | int __user *p = argp; |
143 | int interval; |
144 | |
145 | static const struct watchdog_info ident = { |
146 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
147 | | WDIOF_MAGICCLOSE, |
148 | .firmware_version = 1, |
149 | .identity = WATCHDOG_NAME, |
150 | }; |
151 | |
152 | switch (cmd) { |
153 | case WDIOC_GETSUPPORT: |
154 | return copy_to_user(argp, &ident, |
155 | sizeof(ident)) ? -EFAULT : 0; |
156 | break; |
157 | |
158 | case WDIOC_GETSTATUS: |
159 | case WDIOC_GETBOOTSTATUS: |
160 | return put_user(0, p); |
161 | |
162 | case WDIOC_SETOPTIONS: |
163 | { |
164 | int options, ret = -EINVAL; |
165 | |
166 | if (get_user(options, p)) |
167 | return -EFAULT; |
168 | |
169 | if (options & WDIOS_DISABLECARD) { |
170 | geodewdt_disable(); |
171 | ret = 0; |
172 | } |
173 | |
174 | if (options & WDIOS_ENABLECARD) { |
175 | geodewdt_ping(); |
176 | ret = 0; |
177 | } |
178 | |
179 | return ret; |
180 | } |
181 | case WDIOC_KEEPALIVE: |
182 | geodewdt_ping(); |
183 | return 0; |
184 | |
185 | case WDIOC_SETTIMEOUT: |
186 | if (get_user(interval, p)) |
187 | return -EFAULT; |
188 | |
189 | if (geodewdt_set_heartbeat(interval)) |
190 | return -EINVAL; |
191 | /* Fall through */ |
192 | case WDIOC_GETTIMEOUT: |
193 | return put_user(timeout, p); |
194 | |
195 | default: |
196 | return -ENOTTY; |
197 | } |
198 | |
199 | return 0; |
200 | } |
201 | |
202 | static const struct file_operations geodewdt_fops = { |
203 | .owner = THIS_MODULE, |
204 | .llseek = no_llseek, |
205 | .write = geodewdt_write, |
206 | .unlocked_ioctl = geodewdt_ioctl, |
207 | .open = geodewdt_open, |
208 | .release = geodewdt_release, |
209 | }; |
210 | |
211 | static struct miscdevice geodewdt_miscdev = { |
212 | .minor = WATCHDOG_MINOR, |
213 | .name = "watchdog", |
214 | .fops = &geodewdt_fops, |
215 | }; |
216 | |
217 | static int __devinit geodewdt_probe(struct platform_device *dev) |
218 | { |
219 | int ret; |
220 | |
221 | wdt_timer = cs5535_mfgpt_alloc_timer(MFGPT_TIMER_ANY, MFGPT_DOMAIN_WORKING); |
222 | if (!wdt_timer) { |
223 | printk(KERN_ERR "geodewdt: No timers were available\n"); |
224 | return -ENODEV; |
225 | } |
226 | |
227 | /* Set up the timer */ |
228 | |
229 | cs5535_mfgpt_write(wdt_timer, MFGPT_REG_SETUP, |
230 | GEODEWDT_SCALE | (3 << 8)); |
231 | |
232 | /* Set up comparator 2 to reset when the event fires */ |
233 | cs5535_mfgpt_toggle_event(wdt_timer, MFGPT_CMP2, MFGPT_EVENT_RESET, 1); |
234 | |
235 | /* Set up the initial timeout */ |
236 | |
237 | cs5535_mfgpt_write(wdt_timer, MFGPT_REG_CMP2, |
238 | timeout * GEODEWDT_HZ); |
239 | |
240 | ret = misc_register(&geodewdt_miscdev); |
241 | |
242 | return ret; |
243 | } |
244 | |
245 | static int __devexit geodewdt_remove(struct platform_device *dev) |
246 | { |
247 | misc_deregister(&geodewdt_miscdev); |
248 | return 0; |
249 | } |
250 | |
251 | static void geodewdt_shutdown(struct platform_device *dev) |
252 | { |
253 | geodewdt_disable(); |
254 | } |
255 | |
256 | static struct platform_driver geodewdt_driver = { |
257 | .probe = geodewdt_probe, |
258 | .remove = __devexit_p(geodewdt_remove), |
259 | .shutdown = geodewdt_shutdown, |
260 | .driver = { |
261 | .owner = THIS_MODULE, |
262 | .name = DRV_NAME, |
263 | }, |
264 | }; |
265 | |
266 | static int __init geodewdt_init(void) |
267 | { |
268 | int ret; |
269 | |
270 | ret = platform_driver_register(&geodewdt_driver); |
271 | if (ret) |
272 | return ret; |
273 | |
274 | geodewdt_platform_device = platform_device_register_simple(DRV_NAME, |
275 | -1, NULL, 0); |
276 | if (IS_ERR(geodewdt_platform_device)) { |
277 | ret = PTR_ERR(geodewdt_platform_device); |
278 | goto err; |
279 | } |
280 | |
281 | return 0; |
282 | err: |
283 | platform_driver_unregister(&geodewdt_driver); |
284 | return ret; |
285 | } |
286 | |
287 | static void __exit geodewdt_exit(void) |
288 | { |
289 | platform_device_unregister(geodewdt_platform_device); |
290 | platform_driver_unregister(&geodewdt_driver); |
291 | } |
292 | |
293 | module_init(geodewdt_init); |
294 | module_exit(geodewdt_exit); |
295 | |
296 | MODULE_AUTHOR("Advanced Micro Devices, Inc"); |
297 | MODULE_DESCRIPTION("Geode GX/LX Watchdog Driver"); |
298 | MODULE_LICENSE("GPL"); |
299 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
300 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9