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/at32ap700x_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/at32ap700x_wdt.c')
-rw-r--r-- | drivers/watchdog/at32ap700x_wdt.c | 386 |
1 files changed, 386 insertions, 0 deletions
diff --git a/drivers/watchdog/at32ap700x_wdt.c b/drivers/watchdog/at32ap700x_wdt.c new file mode 100644 index 000000000000..54a516169d07 --- /dev/null +++ b/drivers/watchdog/at32ap700x_wdt.c | |||
@@ -0,0 +1,386 @@ | |||
1 | /* | ||
2 | * Watchdog driver for Atmel AT32AP700X devices | ||
3 | * | ||
4 | * Copyright (C) 2005-2006 Atmel Corporation | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU General Public License version 2 as | ||
8 | * published by the Free Software Foundation. | ||
9 | */ | ||
10 | |||
11 | #include <linux/init.h> | ||
12 | #include <linux/kernel.h> | ||
13 | #include <linux/module.h> | ||
14 | #include <linux/moduleparam.h> | ||
15 | #include <linux/miscdevice.h> | ||
16 | #include <linux/fs.h> | ||
17 | #include <linux/platform_device.h> | ||
18 | #include <linux/watchdog.h> | ||
19 | #include <linux/uaccess.h> | ||
20 | #include <linux/io.h> | ||
21 | #include <linux/spinlock.h> | ||
22 | |||
23 | #define TIMEOUT_MIN 1 | ||
24 | #define TIMEOUT_MAX 2 | ||
25 | #define TIMEOUT_DEFAULT TIMEOUT_MAX | ||
26 | |||
27 | /* module parameters */ | ||
28 | static int timeout = TIMEOUT_DEFAULT; | ||
29 | module_param(timeout, int, 0); | ||
30 | MODULE_PARM_DESC(timeout, | ||
31 | "Timeout value. Limited to be 1 or 2 seconds. (default=" | ||
32 | __MODULE_STRING(TIMEOUT_DEFAULT) ")"); | ||
33 | |||
34 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
35 | module_param(nowayout, int, 0); | ||
36 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" | ||
37 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | ||
38 | |||
39 | /* Watchdog registers and write/read macro */ | ||
40 | #define WDT_CTRL 0x00 | ||
41 | #define WDT_CTRL_EN 0 | ||
42 | #define WDT_CTRL_PSEL 8 | ||
43 | #define WDT_CTRL_KEY 24 | ||
44 | |||
45 | #define WDT_CLR 0x04 | ||
46 | |||
47 | #define WDT_BIT(name) (1 << WDT_##name) | ||
48 | #define WDT_BF(name, value) ((value) << WDT_##name) | ||
49 | |||
50 | #define wdt_readl(dev, reg) \ | ||
51 | __raw_readl((dev)->regs + WDT_##reg) | ||
52 | #define wdt_writel(dev, reg, value) \ | ||
53 | __raw_writel((value), (dev)->regs + WDT_##reg) | ||
54 | |||
55 | struct wdt_at32ap700x { | ||
56 | void __iomem *regs; | ||
57 | spinlock_t io_lock; | ||
58 | int timeout; | ||
59 | unsigned long users; | ||
60 | struct miscdevice miscdev; | ||
61 | }; | ||
62 | |||
63 | static struct wdt_at32ap700x *wdt; | ||
64 | static char expect_release; | ||
65 | |||
66 | /* | ||
67 | * Disable the watchdog. | ||
68 | */ | ||
69 | static inline void at32_wdt_stop(void) | ||
70 | { | ||
71 | unsigned long psel; | ||
72 | |||
73 | spin_lock(&wdt->io_lock); | ||
74 | psel = wdt_readl(wdt, CTRL) & WDT_BF(CTRL_PSEL, 0x0f); | ||
75 | wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0x55)); | ||
76 | wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0xaa)); | ||
77 | spin_unlock(&wdt->io_lock); | ||
78 | } | ||
79 | |||
80 | /* | ||
81 | * Enable and reset the watchdog. | ||
82 | */ | ||
83 | static inline void at32_wdt_start(void) | ||
84 | { | ||
85 | /* 0xf is 2^16 divider = 2 sec, 0xe is 2^15 divider = 1 sec */ | ||
86 | unsigned long psel = (wdt->timeout > 1) ? 0xf : 0xe; | ||
87 | |||
88 | spin_lock(&wdt->io_lock); | ||
89 | wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN) | ||
90 | | WDT_BF(CTRL_PSEL, psel) | ||
91 | | WDT_BF(CTRL_KEY, 0x55)); | ||
92 | wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN) | ||
93 | | WDT_BF(CTRL_PSEL, psel) | ||
94 | | WDT_BF(CTRL_KEY, 0xaa)); | ||
95 | spin_unlock(&wdt->io_lock); | ||
96 | } | ||
97 | |||
98 | /* | ||
99 | * Pat the watchdog timer. | ||
100 | */ | ||
101 | static inline void at32_wdt_pat(void) | ||
102 | { | ||
103 | spin_lock(&wdt->io_lock); | ||
104 | wdt_writel(wdt, CLR, 0x42); | ||
105 | spin_unlock(&wdt->io_lock); | ||
106 | } | ||
107 | |||
108 | /* | ||
109 | * Watchdog device is opened, and watchdog starts running. | ||
110 | */ | ||
111 | static int at32_wdt_open(struct inode *inode, struct file *file) | ||
112 | { | ||
113 | if (test_and_set_bit(1, &wdt->users)) | ||
114 | return -EBUSY; | ||
115 | |||
116 | at32_wdt_start(); | ||
117 | return nonseekable_open(inode, file); | ||
118 | } | ||
119 | |||
120 | /* | ||
121 | * Close the watchdog device. | ||
122 | */ | ||
123 | static int at32_wdt_close(struct inode *inode, struct file *file) | ||
124 | { | ||
125 | if (expect_release == 42) { | ||
126 | at32_wdt_stop(); | ||
127 | } else { | ||
128 | dev_dbg(wdt->miscdev.parent, | ||
129 | "Unexpected close, not stopping watchdog!\n"); | ||
130 | at32_wdt_pat(); | ||
131 | } | ||
132 | clear_bit(1, &wdt->users); | ||
133 | expect_release = 0; | ||
134 | return 0; | ||
135 | } | ||
136 | |||
137 | /* | ||
138 | * Change the watchdog time interval. | ||
139 | */ | ||
140 | static int at32_wdt_settimeout(int time) | ||
141 | { | ||
142 | /* | ||
143 | * All counting occurs at 1 / SLOW_CLOCK (32 kHz) and max prescaler is | ||
144 | * 2 ^ 16 allowing up to 2 seconds timeout. | ||
145 | */ | ||
146 | if ((time < TIMEOUT_MIN) || (time > TIMEOUT_MAX)) | ||
147 | return -EINVAL; | ||
148 | |||
149 | /* | ||
150 | * Set new watchdog time. It will be used when at32_wdt_start() is | ||
151 | * called. | ||
152 | */ | ||
153 | wdt->timeout = time; | ||
154 | return 0; | ||
155 | } | ||
156 | |||
157 | static struct watchdog_info at32_wdt_info = { | ||
158 | .identity = "at32ap700x watchdog", | ||
159 | .options = WDIOF_SETTIMEOUT | | ||
160 | WDIOF_KEEPALIVEPING | | ||
161 | WDIOF_MAGICCLOSE, | ||
162 | }; | ||
163 | |||
164 | /* | ||
165 | * Handle commands from user-space. | ||
166 | */ | ||
167 | static int at32_wdt_ioctl(struct inode *inode, struct file *file, | ||
168 | unsigned int cmd, unsigned long arg) | ||
169 | { | ||
170 | int ret = -ENOTTY; | ||
171 | int time; | ||
172 | void __user *argp = (void __user *)arg; | ||
173 | int __user *p = argp; | ||
174 | |||
175 | switch (cmd) { | ||
176 | case WDIOC_KEEPALIVE: | ||
177 | at32_wdt_pat(); | ||
178 | ret = 0; | ||
179 | break; | ||
180 | case WDIOC_GETSUPPORT: | ||
181 | ret = copy_to_user(argp, &at32_wdt_info, | ||
182 | sizeof(at32_wdt_info)) ? -EFAULT : 0; | ||
183 | break; | ||
184 | case WDIOC_SETTIMEOUT: | ||
185 | ret = get_user(time, p); | ||
186 | if (ret) | ||
187 | break; | ||
188 | ret = at32_wdt_settimeout(time); | ||
189 | if (ret) | ||
190 | break; | ||
191 | /* Enable new time value */ | ||
192 | at32_wdt_start(); | ||
193 | /* fall through */ | ||
194 | case WDIOC_GETTIMEOUT: | ||
195 | ret = put_user(wdt->timeout, p); | ||
196 | break; | ||
197 | case WDIOC_GETSTATUS: /* fall through */ | ||
198 | case WDIOC_GETBOOTSTATUS: | ||
199 | ret = put_user(0, p); | ||
200 | break; | ||
201 | case WDIOC_SETOPTIONS: | ||
202 | ret = get_user(time, p); | ||
203 | if (ret) | ||
204 | break; | ||
205 | if (time & WDIOS_DISABLECARD) | ||
206 | at32_wdt_stop(); | ||
207 | if (time & WDIOS_ENABLECARD) | ||
208 | at32_wdt_start(); | ||
209 | ret = 0; | ||
210 | break; | ||
211 | } | ||
212 | |||
213 | return ret; | ||
214 | } | ||
215 | |||
216 | static ssize_t at32_wdt_write(struct file *file, const char __user *data, | ||
217 | size_t len, loff_t *ppos) | ||
218 | { | ||
219 | /* See if we got the magic character 'V' and reload the timer */ | ||
220 | if (len) { | ||
221 | if (!nowayout) { | ||
222 | size_t i; | ||
223 | |||
224 | /* | ||
225 | * note: just in case someone wrote the magic | ||
226 | * character five months ago... | ||
227 | */ | ||
228 | expect_release = 0; | ||
229 | |||
230 | /* | ||
231 | * scan to see whether or not we got the magic | ||
232 | * character | ||
233 | */ | ||
234 | for (i = 0; i != len; i++) { | ||
235 | char c; | ||
236 | if (get_user(c, data+i)) | ||
237 | return -EFAULT; | ||
238 | if (c == 'V') | ||
239 | expect_release = 42; | ||
240 | } | ||
241 | } | ||
242 | /* someone wrote to us, we should pat the watchdog */ | ||
243 | at32_wdt_pat(); | ||
244 | } | ||
245 | return len; | ||
246 | } | ||
247 | |||
248 | static const struct file_operations at32_wdt_fops = { | ||
249 | .owner = THIS_MODULE, | ||
250 | .llseek = no_llseek, | ||
251 | .ioctl = at32_wdt_ioctl, | ||
252 | .open = at32_wdt_open, | ||
253 | .release = at32_wdt_close, | ||
254 | .write = at32_wdt_write, | ||
255 | }; | ||
256 | |||
257 | static int __init at32_wdt_probe(struct platform_device *pdev) | ||
258 | { | ||
259 | struct resource *regs; | ||
260 | int ret; | ||
261 | |||
262 | if (wdt) { | ||
263 | dev_dbg(&pdev->dev, "only 1 wdt instance supported.\n"); | ||
264 | return -EBUSY; | ||
265 | } | ||
266 | |||
267 | regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); | ||
268 | if (!regs) { | ||
269 | dev_dbg(&pdev->dev, "missing mmio resource\n"); | ||
270 | return -ENXIO; | ||
271 | } | ||
272 | |||
273 | wdt = kzalloc(sizeof(struct wdt_at32ap700x), GFP_KERNEL); | ||
274 | if (!wdt) { | ||
275 | dev_dbg(&pdev->dev, "no memory for wdt structure\n"); | ||
276 | return -ENOMEM; | ||
277 | } | ||
278 | |||
279 | wdt->regs = ioremap(regs->start, regs->end - regs->start + 1); | ||
280 | if (!wdt->regs) { | ||
281 | ret = -ENOMEM; | ||
282 | dev_dbg(&pdev->dev, "could not map I/O memory\n"); | ||
283 | goto err_free; | ||
284 | } | ||
285 | spin_lock_init(&wdt->io_lock); | ||
286 | wdt->users = 0; | ||
287 | wdt->miscdev.minor = WATCHDOG_MINOR; | ||
288 | wdt->miscdev.name = "watchdog"; | ||
289 | wdt->miscdev.fops = &at32_wdt_fops; | ||
290 | |||
291 | if (at32_wdt_settimeout(timeout)) { | ||
292 | at32_wdt_settimeout(TIMEOUT_DEFAULT); | ||
293 | dev_dbg(&pdev->dev, | ||
294 | "default timeout invalid, set to %d sec.\n", | ||
295 | TIMEOUT_DEFAULT); | ||
296 | } | ||
297 | |||
298 | ret = misc_register(&wdt->miscdev); | ||
299 | if (ret) { | ||
300 | dev_dbg(&pdev->dev, "failed to register wdt miscdev\n"); | ||
301 | goto err_iounmap; | ||
302 | } | ||
303 | |||
304 | platform_set_drvdata(pdev, wdt); | ||
305 | wdt->miscdev.parent = &pdev->dev; | ||
306 | dev_info(&pdev->dev, | ||
307 | "AT32AP700X WDT at 0x%p, timeout %d sec (nowayout=%d)\n", | ||
308 | wdt->regs, wdt->timeout, nowayout); | ||
309 | |||
310 | return 0; | ||
311 | |||
312 | err_iounmap: | ||
313 | iounmap(wdt->regs); | ||
314 | err_free: | ||
315 | kfree(wdt); | ||
316 | wdt = NULL; | ||
317 | return ret; | ||
318 | } | ||
319 | |||
320 | static int __exit at32_wdt_remove(struct platform_device *pdev) | ||
321 | { | ||
322 | if (wdt && platform_get_drvdata(pdev) == wdt) { | ||
323 | /* Stop the timer before we leave */ | ||
324 | if (!nowayout) | ||
325 | at32_wdt_stop(); | ||
326 | |||
327 | misc_deregister(&wdt->miscdev); | ||
328 | iounmap(wdt->regs); | ||
329 | kfree(wdt); | ||
330 | wdt = NULL; | ||
331 | platform_set_drvdata(pdev, NULL); | ||
332 | } | ||
333 | |||
334 | return 0; | ||
335 | } | ||
336 | |||
337 | static void at32_wdt_shutdown(struct platform_device *pdev) | ||
338 | { | ||
339 | at32_wdt_stop(); | ||
340 | } | ||
341 | |||
342 | #ifdef CONFIG_PM | ||
343 | static int at32_wdt_suspend(struct platform_device *pdev, pm_message_t message) | ||
344 | { | ||
345 | at32_wdt_stop(); | ||
346 | return 0; | ||
347 | } | ||
348 | |||
349 | static int at32_wdt_resume(struct platform_device *pdev) | ||
350 | { | ||
351 | if (wdt->users) | ||
352 | at32_wdt_start(); | ||
353 | return 0; | ||
354 | } | ||
355 | #else | ||
356 | #define at32_wdt_suspend NULL | ||
357 | #define at32_wdt_resume NULL | ||
358 | #endif | ||
359 | |||
360 | static struct platform_driver at32_wdt_driver = { | ||
361 | .remove = __exit_p(at32_wdt_remove), | ||
362 | .suspend = at32_wdt_suspend, | ||
363 | .resume = at32_wdt_resume, | ||
364 | .driver = { | ||
365 | .name = "at32_wdt", | ||
366 | .owner = THIS_MODULE, | ||
367 | }, | ||
368 | .shutdown = at32_wdt_shutdown, | ||
369 | }; | ||
370 | |||
371 | static int __init at32_wdt_init(void) | ||
372 | { | ||
373 | return platform_driver_probe(&at32_wdt_driver, at32_wdt_probe); | ||
374 | } | ||
375 | module_init(at32_wdt_init); | ||
376 | |||
377 | static void __exit at32_wdt_exit(void) | ||
378 | { | ||
379 | platform_driver_unregister(&at32_wdt_driver); | ||
380 | } | ||
381 | module_exit(at32_wdt_exit); | ||
382 | |||
383 | MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>"); | ||
384 | MODULE_DESCRIPTION("Watchdog driver for Atmel AT32AP700X"); | ||
385 | MODULE_LICENSE("GPL"); | ||
386 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||