diff options
author | Wim Van Sebroeck <wim@iguana.be> | 2007-08-17 04:38:02 -0400 |
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committer | Wim Van Sebroeck <wim@iguana.be> | 2007-10-18 06:39:03 -0400 |
commit | b7e04f8c61a46d742de23af5d7ca2b41b33e40ac (patch) | |
tree | c52a7ea568648e2d8ed0d423098b42298de2058b /drivers/watchdog/at91rm9200_wdt.c | |
parent | d85714d81cc0408daddb68c10f7fd69eafe7c213 (diff) |
mv watchdog tree under drivers
move watchdog tree from drivers/char/watchdog to drivers/watchdog.
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/at91rm9200_wdt.c')
-rw-r--r-- | drivers/watchdog/at91rm9200_wdt.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/drivers/watchdog/at91rm9200_wdt.c b/drivers/watchdog/at91rm9200_wdt.c new file mode 100644 index 000000000000..38bd37372599 --- /dev/null +++ b/drivers/watchdog/at91rm9200_wdt.c | |||
@@ -0,0 +1,288 @@ | |||
1 | /* | ||
2 | * Watchdog driver for Atmel AT91RM9200 (Thunder) | ||
3 | * | ||
4 | * Copyright (C) 2003 SAN People (Pty) Ltd | ||
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 | #include <linux/errno.h> | ||
13 | #include <linux/fs.h> | ||
14 | #include <linux/init.h> | ||
15 | #include <linux/kernel.h> | ||
16 | #include <linux/miscdevice.h> | ||
17 | #include <linux/module.h> | ||
18 | #include <linux/moduleparam.h> | ||
19 | #include <linux/platform_device.h> | ||
20 | #include <linux/types.h> | ||
21 | #include <linux/watchdog.h> | ||
22 | #include <asm/bitops.h> | ||
23 | #include <asm/uaccess.h> | ||
24 | #include <asm/arch/at91_st.h> | ||
25 | |||
26 | |||
27 | #define WDT_DEFAULT_TIME 5 /* seconds */ | ||
28 | #define WDT_MAX_TIME 256 /* seconds */ | ||
29 | |||
30 | static int wdt_time = WDT_DEFAULT_TIME; | ||
31 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
32 | |||
33 | module_param(wdt_time, int, 0); | ||
34 | MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="__MODULE_STRING(WDT_DEFAULT_TIME) ")"); | ||
35 | |||
36 | #ifdef CONFIG_WATCHDOG_NOWAYOUT | ||
37 | module_param(nowayout, int, 0); | ||
38 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | ||
39 | #endif | ||
40 | |||
41 | |||
42 | static unsigned long at91wdt_busy; | ||
43 | |||
44 | /* ......................................................................... */ | ||
45 | |||
46 | /* | ||
47 | * Disable the watchdog. | ||
48 | */ | ||
49 | static void inline at91_wdt_stop(void) | ||
50 | { | ||
51 | at91_sys_write(AT91_ST_WDMR, AT91_ST_EXTEN); | ||
52 | } | ||
53 | |||
54 | /* | ||
55 | * Enable and reset the watchdog. | ||
56 | */ | ||
57 | static void inline at91_wdt_start(void) | ||
58 | { | ||
59 | at91_sys_write(AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN | (((65536 * wdt_time) >> 8) & AT91_ST_WDV)); | ||
60 | at91_sys_write(AT91_ST_CR, AT91_ST_WDRST); | ||
61 | } | ||
62 | |||
63 | /* | ||
64 | * Reload the watchdog timer. (ie, pat the watchdog) | ||
65 | */ | ||
66 | static void inline at91_wdt_reload(void) | ||
67 | { | ||
68 | at91_sys_write(AT91_ST_CR, AT91_ST_WDRST); | ||
69 | } | ||
70 | |||
71 | /* ......................................................................... */ | ||
72 | |||
73 | /* | ||
74 | * Watchdog device is opened, and watchdog starts running. | ||
75 | */ | ||
76 | static int at91_wdt_open(struct inode *inode, struct file *file) | ||
77 | { | ||
78 | if (test_and_set_bit(0, &at91wdt_busy)) | ||
79 | return -EBUSY; | ||
80 | |||
81 | at91_wdt_start(); | ||
82 | return nonseekable_open(inode, file); | ||
83 | } | ||
84 | |||
85 | /* | ||
86 | * Close the watchdog device. | ||
87 | * If CONFIG_WATCHDOG_NOWAYOUT is NOT defined then the watchdog is also | ||
88 | * disabled. | ||
89 | */ | ||
90 | static int at91_wdt_close(struct inode *inode, struct file *file) | ||
91 | { | ||
92 | if (!nowayout) | ||
93 | at91_wdt_stop(); /* Disable the watchdog when file is closed */ | ||
94 | |||
95 | clear_bit(0, &at91wdt_busy); | ||
96 | return 0; | ||
97 | } | ||
98 | |||
99 | /* | ||
100 | * Change the watchdog time interval. | ||
101 | */ | ||
102 | static int at91_wdt_settimeout(int new_time) | ||
103 | { | ||
104 | /* | ||
105 | * All counting occurs at SLOW_CLOCK / 128 = 0.256 Hz | ||
106 | * | ||
107 | * Since WDV is a 16-bit counter, the maximum period is | ||
108 | * 65536 / 0.256 = 256 seconds. | ||
109 | */ | ||
110 | if ((new_time <= 0) || (new_time > WDT_MAX_TIME)) | ||
111 | return -EINVAL; | ||
112 | |||
113 | /* Set new watchdog time. It will be used when at91_wdt_start() is called. */ | ||
114 | wdt_time = new_time; | ||
115 | return 0; | ||
116 | } | ||
117 | |||
118 | static struct watchdog_info at91_wdt_info = { | ||
119 | .identity = "at91 watchdog", | ||
120 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | ||
121 | }; | ||
122 | |||
123 | /* | ||
124 | * Handle commands from user-space. | ||
125 | */ | ||
126 | static int at91_wdt_ioctl(struct inode *inode, struct file *file, | ||
127 | unsigned int cmd, unsigned long arg) | ||
128 | { | ||
129 | void __user *argp = (void __user *)arg; | ||
130 | int __user *p = argp; | ||
131 | int new_value; | ||
132 | |||
133 | switch(cmd) { | ||
134 | case WDIOC_KEEPALIVE: | ||
135 | at91_wdt_reload(); /* pat the watchdog */ | ||
136 | return 0; | ||
137 | |||
138 | case WDIOC_GETSUPPORT: | ||
139 | return copy_to_user(argp, &at91_wdt_info, sizeof(at91_wdt_info)) ? -EFAULT : 0; | ||
140 | |||
141 | case WDIOC_SETTIMEOUT: | ||
142 | if (get_user(new_value, p)) | ||
143 | return -EFAULT; | ||
144 | |||
145 | if (at91_wdt_settimeout(new_value)) | ||
146 | return -EINVAL; | ||
147 | |||
148 | /* Enable new time value */ | ||
149 | at91_wdt_start(); | ||
150 | |||
151 | /* Return current value */ | ||
152 | return put_user(wdt_time, p); | ||
153 | |||
154 | case WDIOC_GETTIMEOUT: | ||
155 | return put_user(wdt_time, p); | ||
156 | |||
157 | case WDIOC_GETSTATUS: | ||
158 | case WDIOC_GETBOOTSTATUS: | ||
159 | return put_user(0, p); | ||
160 | |||
161 | case WDIOC_SETOPTIONS: | ||
162 | if (get_user(new_value, p)) | ||
163 | return -EFAULT; | ||
164 | |||
165 | if (new_value & WDIOS_DISABLECARD) | ||
166 | at91_wdt_stop(); | ||
167 | if (new_value & WDIOS_ENABLECARD) | ||
168 | at91_wdt_start(); | ||
169 | return 0; | ||
170 | |||
171 | default: | ||
172 | return -ENOTTY; | ||
173 | } | ||
174 | } | ||
175 | |||
176 | /* | ||
177 | * Pat the watchdog whenever device is written to. | ||
178 | */ | ||
179 | static ssize_t at91_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) | ||
180 | { | ||
181 | at91_wdt_reload(); /* pat the watchdog */ | ||
182 | return len; | ||
183 | } | ||
184 | |||
185 | /* ......................................................................... */ | ||
186 | |||
187 | static const struct file_operations at91wdt_fops = { | ||
188 | .owner = THIS_MODULE, | ||
189 | .llseek = no_llseek, | ||
190 | .ioctl = at91_wdt_ioctl, | ||
191 | .open = at91_wdt_open, | ||
192 | .release = at91_wdt_close, | ||
193 | .write = at91_wdt_write, | ||
194 | }; | ||
195 | |||
196 | static struct miscdevice at91wdt_miscdev = { | ||
197 | .minor = WATCHDOG_MINOR, | ||
198 | .name = "watchdog", | ||
199 | .fops = &at91wdt_fops, | ||
200 | }; | ||
201 | |||
202 | static int __init at91wdt_probe(struct platform_device *pdev) | ||
203 | { | ||
204 | int res; | ||
205 | |||
206 | if (at91wdt_miscdev.parent) | ||
207 | return -EBUSY; | ||
208 | at91wdt_miscdev.parent = &pdev->dev; | ||
209 | |||
210 | res = misc_register(&at91wdt_miscdev); | ||
211 | if (res) | ||
212 | return res; | ||
213 | |||
214 | printk("AT91 Watchdog Timer enabled (%d seconds%s)\n", wdt_time, nowayout ? ", nowayout" : ""); | ||
215 | return 0; | ||
216 | } | ||
217 | |||
218 | static int __exit at91wdt_remove(struct platform_device *pdev) | ||
219 | { | ||
220 | int res; | ||
221 | |||
222 | res = misc_deregister(&at91wdt_miscdev); | ||
223 | if (!res) | ||
224 | at91wdt_miscdev.parent = NULL; | ||
225 | |||
226 | return res; | ||
227 | } | ||
228 | |||
229 | static void at91wdt_shutdown(struct platform_device *pdev) | ||
230 | { | ||
231 | at91_wdt_stop(); | ||
232 | } | ||
233 | |||
234 | #ifdef CONFIG_PM | ||
235 | |||
236 | static int at91wdt_suspend(struct platform_device *pdev, pm_message_t message) | ||
237 | { | ||
238 | at91_wdt_stop(); | ||
239 | return 0; | ||
240 | } | ||
241 | |||
242 | static int at91wdt_resume(struct platform_device *pdev) | ||
243 | { | ||
244 | if (at91wdt_busy) | ||
245 | at91_wdt_start(); | ||
246 | return 0; | ||
247 | } | ||
248 | |||
249 | #else | ||
250 | #define at91wdt_suspend NULL | ||
251 | #define at91wdt_resume NULL | ||
252 | #endif | ||
253 | |||
254 | static struct platform_driver at91wdt_driver = { | ||
255 | .probe = at91wdt_probe, | ||
256 | .remove = __exit_p(at91wdt_remove), | ||
257 | .shutdown = at91wdt_shutdown, | ||
258 | .suspend = at91wdt_suspend, | ||
259 | .resume = at91wdt_resume, | ||
260 | .driver = { | ||
261 | .name = "at91_wdt", | ||
262 | .owner = THIS_MODULE, | ||
263 | }, | ||
264 | }; | ||
265 | |||
266 | static int __init at91_wdt_init(void) | ||
267 | { | ||
268 | /* Check that the heartbeat value is within range; if not reset to the default */ | ||
269 | if (at91_wdt_settimeout(wdt_time)) { | ||
270 | at91_wdt_settimeout(WDT_DEFAULT_TIME); | ||
271 | pr_info("at91_wdt: wdt_time value must be 1 <= wdt_time <= 256, using %d\n", wdt_time); | ||
272 | } | ||
273 | |||
274 | return platform_driver_register(&at91wdt_driver); | ||
275 | } | ||
276 | |||
277 | static void __exit at91_wdt_exit(void) | ||
278 | { | ||
279 | platform_driver_unregister(&at91wdt_driver); | ||
280 | } | ||
281 | |||
282 | module_init(at91_wdt_init); | ||
283 | module_exit(at91_wdt_exit); | ||
284 | |||
285 | MODULE_AUTHOR("Andrew Victor"); | ||
286 | MODULE_DESCRIPTION("Watchdog driver for Atmel AT91RM9200"); | ||
287 | MODULE_LICENSE("GPL"); | ||
288 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||