]>
Commit | Line | Data |
---|---|---|
38461c5c TR |
1 | /* |
2 | * Copyright (C) 2008-2009 Avionic Design GmbH | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | */ | |
8 | ||
9 | #include <linux/fs.h> | |
10 | #include <linux/io.h> | |
11 | #include <linux/miscdevice.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/platform_device.h> | |
14 | #include <linux/types.h> | |
15 | #include <linux/uaccess.h> | |
16 | #include <linux/watchdog.h> | |
17 | ||
18 | #define WATCHDOG_NAME "adx-wdt" | |
19 | ||
20 | /* register offsets */ | |
21 | #define ADX_WDT_CONTROL 0x00 | |
22 | #define ADX_WDT_CONTROL_ENABLE (1 << 0) | |
23 | #define ADX_WDT_CONTROL_nRESET (1 << 1) | |
24 | #define ADX_WDT_TIMEOUT 0x08 | |
25 | ||
26 | static struct platform_device *adx_wdt_dev; | |
27 | static unsigned long driver_open; | |
28 | ||
29 | #define WDT_STATE_STOP 0 | |
30 | #define WDT_STATE_START 1 | |
31 | ||
32 | struct adx_wdt { | |
33 | void __iomem *base; | |
34 | unsigned long timeout; | |
35 | unsigned int state; | |
36 | unsigned int wake; | |
37 | spinlock_t lock; | |
38 | }; | |
39 | ||
40 | static struct watchdog_info adx_wdt_info = { | |
41 | .identity = "Avionic Design Xanthos Watchdog", | |
42 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
43 | }; | |
44 | ||
45 | static void adx_wdt_start_locked(struct adx_wdt *wdt) | |
46 | { | |
47 | u32 ctrl; | |
48 | ||
49 | ctrl = readl(wdt->base + ADX_WDT_CONTROL); | |
50 | ctrl |= ADX_WDT_CONTROL_ENABLE; | |
51 | writel(ctrl, wdt->base + ADX_WDT_CONTROL); | |
52 | wdt->state = WDT_STATE_START; | |
53 | } | |
54 | ||
55 | static void adx_wdt_start(struct adx_wdt *wdt) | |
56 | { | |
57 | unsigned long flags; | |
58 | ||
59 | spin_lock_irqsave(&wdt->lock, flags); | |
60 | adx_wdt_start_locked(wdt); | |
61 | spin_unlock_irqrestore(&wdt->lock, flags); | |
62 | } | |
63 | ||
64 | static void adx_wdt_stop_locked(struct adx_wdt *wdt) | |
65 | { | |
66 | u32 ctrl; | |
67 | ||
68 | ctrl = readl(wdt->base + ADX_WDT_CONTROL); | |
69 | ctrl &= ~ADX_WDT_CONTROL_ENABLE; | |
70 | writel(ctrl, wdt->base + ADX_WDT_CONTROL); | |
71 | wdt->state = WDT_STATE_STOP; | |
72 | } | |
73 | ||
74 | static void adx_wdt_stop(struct adx_wdt *wdt) | |
75 | { | |
76 | unsigned long flags; | |
77 | ||
78 | spin_lock_irqsave(&wdt->lock, flags); | |
79 | adx_wdt_stop_locked(wdt); | |
80 | spin_unlock_irqrestore(&wdt->lock, flags); | |
81 | } | |
82 | ||
83 | static void adx_wdt_set_timeout(struct adx_wdt *wdt, unsigned long seconds) | |
84 | { | |
85 | unsigned long timeout = seconds * 1000; | |
86 | unsigned long flags; | |
87 | unsigned int state; | |
88 | ||
89 | spin_lock_irqsave(&wdt->lock, flags); | |
90 | state = wdt->state; | |
91 | adx_wdt_stop_locked(wdt); | |
92 | writel(timeout, wdt->base + ADX_WDT_TIMEOUT); | |
93 | ||
94 | if (state == WDT_STATE_START) | |
95 | adx_wdt_start_locked(wdt); | |
96 | ||
97 | wdt->timeout = timeout; | |
98 | spin_unlock_irqrestore(&wdt->lock, flags); | |
99 | } | |
100 | ||
101 | static void adx_wdt_get_timeout(struct adx_wdt *wdt, unsigned long *seconds) | |
102 | { | |
103 | *seconds = wdt->timeout / 1000; | |
104 | } | |
105 | ||
106 | static void adx_wdt_keepalive(struct adx_wdt *wdt) | |
107 | { | |
108 | unsigned long flags; | |
109 | ||
110 | spin_lock_irqsave(&wdt->lock, flags); | |
111 | writel(wdt->timeout, wdt->base + ADX_WDT_TIMEOUT); | |
112 | spin_unlock_irqrestore(&wdt->lock, flags); | |
113 | } | |
114 | ||
115 | static int adx_wdt_open(struct inode *inode, struct file *file) | |
116 | { | |
117 | struct adx_wdt *wdt = platform_get_drvdata(adx_wdt_dev); | |
118 | ||
119 | if (test_and_set_bit(0, &driver_open)) | |
120 | return -EBUSY; | |
121 | ||
122 | file->private_data = wdt; | |
123 | adx_wdt_set_timeout(wdt, 30); | |
124 | adx_wdt_start(wdt); | |
125 | ||
126 | return nonseekable_open(inode, file); | |
127 | } | |
128 | ||
129 | static int adx_wdt_release(struct inode *inode, struct file *file) | |
130 | { | |
131 | struct adx_wdt *wdt = file->private_data; | |
132 | ||
133 | adx_wdt_stop(wdt); | |
134 | clear_bit(0, &driver_open); | |
135 | ||
136 | return 0; | |
137 | } | |
138 | ||
139 | static long adx_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
140 | { | |
141 | struct adx_wdt *wdt = file->private_data; | |
142 | void __user *argp = (void __user *)arg; | |
143 | unsigned long __user *p = argp; | |
144 | unsigned long seconds = 0; | |
145 | unsigned int options; | |
146 | long ret = -EINVAL; | |
147 | ||
148 | switch (cmd) { | |
149 | case WDIOC_GETSUPPORT: | |
150 | if (copy_to_user(argp, &adx_wdt_info, sizeof(adx_wdt_info))) | |
151 | return -EFAULT; | |
152 | else | |
153 | return 0; | |
154 | ||
155 | case WDIOC_GETSTATUS: | |
156 | case WDIOC_GETBOOTSTATUS: | |
157 | return put_user(0, p); | |
158 | ||
159 | case WDIOC_KEEPALIVE: | |
160 | adx_wdt_keepalive(wdt); | |
161 | return 0; | |
162 | ||
163 | case WDIOC_SETTIMEOUT: | |
164 | if (get_user(seconds, p)) | |
165 | return -EFAULT; | |
166 | ||
167 | adx_wdt_set_timeout(wdt, seconds); | |
168 | ||
169 | /* fallthrough */ | |
170 | case WDIOC_GETTIMEOUT: | |
171 | adx_wdt_get_timeout(wdt, &seconds); | |
172 | return put_user(seconds, p); | |
173 | ||
174 | case WDIOC_SETOPTIONS: | |
175 | if (copy_from_user(&options, argp, sizeof(options))) | |
176 | return -EFAULT; | |
177 | ||
178 | if (options & WDIOS_DISABLECARD) { | |
179 | adx_wdt_stop(wdt); | |
180 | ret = 0; | |
181 | } | |
182 | ||
183 | if (options & WDIOS_ENABLECARD) { | |
184 | adx_wdt_start(wdt); | |
185 | ret = 0; | |
186 | } | |
187 | ||
188 | return ret; | |
189 | ||
190 | default: | |
191 | break; | |
192 | } | |
193 | ||
194 | return -ENOTTY; | |
195 | } | |
196 | ||
197 | static ssize_t adx_wdt_write(struct file *file, const char __user *data, | |
198 | size_t len, loff_t *ppos) | |
199 | { | |
200 | struct adx_wdt *wdt = file->private_data; | |
201 | ||
202 | if (len) | |
203 | adx_wdt_keepalive(wdt); | |
204 | ||
205 | return len; | |
206 | } | |
207 | ||
208 | static const struct file_operations adx_wdt_fops = { | |
209 | .owner = THIS_MODULE, | |
210 | .llseek = no_llseek, | |
211 | .open = adx_wdt_open, | |
212 | .release = adx_wdt_release, | |
213 | .unlocked_ioctl = adx_wdt_ioctl, | |
214 | .write = adx_wdt_write, | |
215 | }; | |
216 | ||
217 | static struct miscdevice adx_wdt_miscdev = { | |
218 | .minor = WATCHDOG_MINOR, | |
219 | .name = "watchdog", | |
220 | .fops = &adx_wdt_fops, | |
221 | }; | |
222 | ||
223 | static int __devinit adx_wdt_probe(struct platform_device *pdev) | |
224 | { | |
225 | struct resource *res; | |
226 | struct adx_wdt *wdt; | |
227 | int ret = 0; | |
228 | u32 ctrl; | |
229 | ||
230 | wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); | |
231 | if (!wdt) { | |
232 | dev_err(&pdev->dev, "cannot allocate WDT structure\n"); | |
233 | return -ENOMEM; | |
234 | } | |
235 | ||
236 | spin_lock_init(&wdt->lock); | |
237 | ||
238 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
239 | if (!res) { | |
240 | dev_err(&pdev->dev, "cannot obtain I/O memory region\n"); | |
241 | return -ENXIO; | |
242 | } | |
243 | ||
244 | res = devm_request_mem_region(&pdev->dev, res->start, | |
245 | res->end - res->start + 1, res->name); | |
246 | if (!res) { | |
247 | dev_err(&pdev->dev, "cannot request I/O memory region\n"); | |
248 | return -ENXIO; | |
249 | } | |
250 | ||
251 | wdt->base = devm_ioremap_nocache(&pdev->dev, res->start, | |
252 | res->end - res->start + 1); | |
253 | if (!wdt->base) { | |
254 | dev_err(&pdev->dev, "cannot remap I/O memory region\n"); | |
255 | return -ENXIO; | |
256 | } | |
257 | ||
258 | /* disable watchdog and reboot on timeout */ | |
259 | ctrl = readl(wdt->base + ADX_WDT_CONTROL); | |
260 | ctrl &= ~ADX_WDT_CONTROL_ENABLE; | |
261 | ctrl &= ~ADX_WDT_CONTROL_nRESET; | |
262 | writel(ctrl, wdt->base + ADX_WDT_CONTROL); | |
263 | ||
264 | platform_set_drvdata(pdev, wdt); | |
265 | adx_wdt_dev = pdev; | |
266 | ||
267 | ret = misc_register(&adx_wdt_miscdev); | |
268 | if (ret) { | |
269 | dev_err(&pdev->dev, "cannot register miscdev on minor %d " | |
270 | "(err=%d)\n", WATCHDOG_MINOR, ret); | |
271 | return ret; | |
272 | } | |
273 | ||
274 | return 0; | |
275 | } | |
276 | ||
277 | static int __devexit adx_wdt_remove(struct platform_device *pdev) | |
278 | { | |
279 | struct adx_wdt *wdt = platform_get_drvdata(pdev); | |
280 | ||
281 | misc_deregister(&adx_wdt_miscdev); | |
282 | adx_wdt_stop(wdt); | |
283 | platform_set_drvdata(pdev, NULL); | |
284 | ||
285 | return 0; | |
286 | } | |
287 | ||
288 | static void adx_wdt_shutdown(struct platform_device *pdev) | |
289 | { | |
290 | struct adx_wdt *wdt = platform_get_drvdata(pdev); | |
291 | adx_wdt_stop(wdt); | |
292 | } | |
293 | ||
294 | #ifdef CONFIG_PM | |
295 | static int adx_wdt_suspend(struct device *dev) | |
296 | { | |
297 | struct platform_device *pdev = to_platform_device(dev); | |
298 | struct adx_wdt *wdt = platform_get_drvdata(pdev); | |
299 | ||
300 | wdt->wake = (wdt->state == WDT_STATE_START) ? 1 : 0; | |
301 | adx_wdt_stop(wdt); | |
302 | ||
303 | return 0; | |
304 | } | |
305 | ||
306 | static int adx_wdt_resume(struct device *dev) | |
307 | { | |
308 | struct platform_device *pdev = to_platform_device(dev); | |
309 | struct adx_wdt *wdt = platform_get_drvdata(pdev); | |
310 | ||
311 | if (wdt->wake) | |
312 | adx_wdt_start(wdt); | |
313 | ||
314 | return 0; | |
315 | } | |
316 | ||
47145210 | 317 | static const struct dev_pm_ops adx_wdt_pm_ops = { |
38461c5c TR |
318 | .suspend = adx_wdt_suspend, |
319 | .resume = adx_wdt_resume, | |
320 | }; | |
321 | ||
322 | # define ADX_WDT_PM_OPS (&adx_wdt_pm_ops) | |
323 | #else | |
324 | # define ADX_WDT_PM_OPS NULL | |
325 | #endif | |
326 | ||
327 | static struct platform_driver adx_wdt_driver = { | |
328 | .probe = adx_wdt_probe, | |
329 | .remove = __devexit_p(adx_wdt_remove), | |
330 | .shutdown = adx_wdt_shutdown, | |
331 | .driver = { | |
332 | .name = WATCHDOG_NAME, | |
333 | .owner = THIS_MODULE, | |
334 | .pm = ADX_WDT_PM_OPS, | |
335 | }, | |
336 | }; | |
337 | ||
338 | static int __init adx_wdt_init(void) | |
339 | { | |
340 | return platform_driver_register(&adx_wdt_driver); | |
341 | } | |
342 | ||
343 | static void __exit adx_wdt_exit(void) | |
344 | { | |
345 | platform_driver_unregister(&adx_wdt_driver); | |
346 | } | |
347 | ||
348 | module_init(adx_wdt_init); | |
349 | module_exit(adx_wdt_exit); | |
350 | ||
351 | MODULE_DESCRIPTION("Avionic Design Xanthos Watchdog Driver"); | |
352 | MODULE_LICENSE("GPL v2"); | |
353 | MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>"); | |
354 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |