diff options
author | Wim Van Sebroeck <wim@iguana.be> | 2007-08-17 04:38:02 -0400 |
---|---|---|
committer | Wim Van Sebroeck <wim@iguana.be> | 2007-10-18 06:39:03 -0400 |
commit | b7e04f8c61a46d742de23af5d7ca2b41b33e40ac (patch) | |
tree | c52a7ea568648e2d8ed0d423098b42298de2058b /drivers/watchdog/alim1535_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/alim1535_wdt.c')
-rw-r--r-- | drivers/watchdog/alim1535_wdt.c | 465 |
1 files changed, 465 insertions, 0 deletions
diff --git a/drivers/watchdog/alim1535_wdt.c b/drivers/watchdog/alim1535_wdt.c new file mode 100644 index 000000000000..c404fc69e7e6 --- /dev/null +++ b/drivers/watchdog/alim1535_wdt.c | |||
@@ -0,0 +1,465 @@ | |||
1 | /* | ||
2 | * Watchdog for the 7101 PMU version found in the ALi M1535 chipsets | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or | ||
5 | * modify it under the terms of the GNU General Public License | ||
6 | * as published by the Free Software Foundation; either version | ||
7 | * 2 of the License, or (at your option) any later version. | ||
8 | */ | ||
9 | |||
10 | #include <linux/module.h> | ||
11 | #include <linux/moduleparam.h> | ||
12 | #include <linux/types.h> | ||
13 | #include <linux/miscdevice.h> | ||
14 | #include <linux/watchdog.h> | ||
15 | #include <linux/ioport.h> | ||
16 | #include <linux/notifier.h> | ||
17 | #include <linux/reboot.h> | ||
18 | #include <linux/init.h> | ||
19 | #include <linux/fs.h> | ||
20 | #include <linux/pci.h> | ||
21 | |||
22 | #include <asm/uaccess.h> | ||
23 | #include <asm/io.h> | ||
24 | |||
25 | #define WATCHDOG_NAME "ALi_M1535" | ||
26 | #define PFX WATCHDOG_NAME ": " | ||
27 | #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ | ||
28 | |||
29 | /* internal variables */ | ||
30 | static unsigned long ali_is_open; | ||
31 | static char ali_expect_release; | ||
32 | static struct pci_dev *ali_pci; | ||
33 | static u32 ali_timeout_bits; /* stores the computed timeout */ | ||
34 | static spinlock_t ali_lock; /* Guards the hardware */ | ||
35 | |||
36 | /* module parameters */ | ||
37 | static int timeout = WATCHDOG_TIMEOUT; | ||
38 | module_param(timeout, int, 0); | ||
39 | MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (0<timeout<18000, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); | ||
40 | |||
41 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
42 | module_param(nowayout, int, 0); | ||
43 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | ||
44 | |||
45 | /* | ||
46 | * ali_start - start watchdog countdown | ||
47 | * | ||
48 | * Starts the timer running providing the timer has a counter | ||
49 | * configuration set. | ||
50 | */ | ||
51 | |||
52 | static void ali_start(void) | ||
53 | { | ||
54 | u32 val; | ||
55 | |||
56 | spin_lock(&ali_lock); | ||
57 | |||
58 | pci_read_config_dword(ali_pci, 0xCC, &val); | ||
59 | val &= ~0x3F; /* Mask count */ | ||
60 | val |= (1<<25) | ali_timeout_bits; | ||
61 | pci_write_config_dword(ali_pci, 0xCC, val); | ||
62 | |||
63 | spin_unlock(&ali_lock); | ||
64 | } | ||
65 | |||
66 | /* | ||
67 | * ali_stop - stop the timer countdown | ||
68 | * | ||
69 | * Stop the ALi watchdog countdown | ||
70 | */ | ||
71 | |||
72 | static void ali_stop(void) | ||
73 | { | ||
74 | u32 val; | ||
75 | |||
76 | spin_lock(&ali_lock); | ||
77 | |||
78 | pci_read_config_dword(ali_pci, 0xCC, &val); | ||
79 | val &= ~0x3F; /* Mask count to zero (disabled) */ | ||
80 | val &= ~(1<<25);/* and for safety mask the reset enable */ | ||
81 | pci_write_config_dword(ali_pci, 0xCC, val); | ||
82 | |||
83 | spin_unlock(&ali_lock); | ||
84 | } | ||
85 | |||
86 | /* | ||
87 | * ali_keepalive - send a keepalive to the watchdog | ||
88 | * | ||
89 | * Send a keepalive to the timer (actually we restart the timer). | ||
90 | */ | ||
91 | |||
92 | static void ali_keepalive(void) | ||
93 | { | ||
94 | ali_start(); | ||
95 | } | ||
96 | |||
97 | /* | ||
98 | * ali_settimer - compute the timer reload value | ||
99 | * @t: time in seconds | ||
100 | * | ||
101 | * Computes the timeout values needed | ||
102 | */ | ||
103 | |||
104 | static int ali_settimer(int t) | ||
105 | { | ||
106 | if(t < 0) | ||
107 | return -EINVAL; | ||
108 | else if(t < 60) | ||
109 | ali_timeout_bits = t|(1<<6); | ||
110 | else if(t < 3600) | ||
111 | ali_timeout_bits = (t/60)|(1<<7); | ||
112 | else if(t < 18000) | ||
113 | ali_timeout_bits = (t/300)|(1<<6)|(1<<7); | ||
114 | else return -EINVAL; | ||
115 | |||
116 | timeout = t; | ||
117 | return 0; | ||
118 | } | ||
119 | |||
120 | /* | ||
121 | * /dev/watchdog handling | ||
122 | */ | ||
123 | |||
124 | /* | ||
125 | * ali_write - writes to ALi watchdog | ||
126 | * @file: file from VFS | ||
127 | * @data: user address of data | ||
128 | * @len: length of data | ||
129 | * @ppos: pointer to the file offset | ||
130 | * | ||
131 | * Handle a write to the ALi watchdog. Writing to the file pings | ||
132 | * the watchdog and resets it. Writing the magic 'V' sequence allows | ||
133 | * the next close to turn off the watchdog. | ||
134 | */ | ||
135 | |||
136 | static ssize_t ali_write(struct file *file, const char __user *data, | ||
137 | size_t len, loff_t * ppos) | ||
138 | { | ||
139 | /* See if we got the magic character 'V' and reload the timer */ | ||
140 | if (len) { | ||
141 | if (!nowayout) { | ||
142 | size_t i; | ||
143 | |||
144 | /* note: just in case someone wrote the magic character | ||
145 | * five months ago... */ | ||
146 | ali_expect_release = 0; | ||
147 | |||
148 | /* scan to see whether or not we got the magic character */ | ||
149 | for (i = 0; i != len; i++) { | ||
150 | char c; | ||
151 | if(get_user(c, data+i)) | ||
152 | return -EFAULT; | ||
153 | if (c == 'V') | ||
154 | ali_expect_release = 42; | ||
155 | } | ||
156 | } | ||
157 | |||
158 | /* someone wrote to us, we should reload the timer */ | ||
159 | ali_start(); | ||
160 | } | ||
161 | return len; | ||
162 | } | ||
163 | |||
164 | /* | ||
165 | * ali_ioctl - handle watchdog ioctls | ||
166 | * @inode: VFS inode | ||
167 | * @file: VFS file pointer | ||
168 | * @cmd: ioctl number | ||
169 | * @arg: arguments to the ioctl | ||
170 | * | ||
171 | * Handle the watchdog ioctls supported by the ALi driver. Really | ||
172 | * we want an extension to enable irq ack monitoring and the like | ||
173 | */ | ||
174 | |||
175 | static int ali_ioctl(struct inode *inode, struct file *file, | ||
176 | unsigned int cmd, unsigned long arg) | ||
177 | { | ||
178 | void __user *argp = (void __user *)arg; | ||
179 | int __user *p = argp; | ||
180 | static struct watchdog_info ident = { | ||
181 | .options = WDIOF_KEEPALIVEPING | | ||
182 | WDIOF_SETTIMEOUT | | ||
183 | WDIOF_MAGICCLOSE, | ||
184 | .firmware_version = 0, | ||
185 | .identity = "ALi M1535 WatchDog Timer", | ||
186 | }; | ||
187 | |||
188 | switch (cmd) { | ||
189 | case WDIOC_GETSUPPORT: | ||
190 | return copy_to_user(argp, &ident, | ||
191 | sizeof (ident)) ? -EFAULT : 0; | ||
192 | |||
193 | case WDIOC_GETSTATUS: | ||
194 | case WDIOC_GETBOOTSTATUS: | ||
195 | return put_user(0, p); | ||
196 | |||
197 | case WDIOC_KEEPALIVE: | ||
198 | ali_keepalive(); | ||
199 | return 0; | ||
200 | |||
201 | case WDIOC_SETOPTIONS: | ||
202 | { | ||
203 | int new_options, retval = -EINVAL; | ||
204 | |||
205 | if (get_user (new_options, p)) | ||
206 | return -EFAULT; | ||
207 | |||
208 | if (new_options & WDIOS_DISABLECARD) { | ||
209 | ali_stop(); | ||
210 | retval = 0; | ||
211 | } | ||
212 | |||
213 | if (new_options & WDIOS_ENABLECARD) { | ||
214 | ali_start(); | ||
215 | retval = 0; | ||
216 | } | ||
217 | |||
218 | return retval; | ||
219 | } | ||
220 | |||
221 | case WDIOC_SETTIMEOUT: | ||
222 | { | ||
223 | int new_timeout; | ||
224 | |||
225 | if (get_user(new_timeout, p)) | ||
226 | return -EFAULT; | ||
227 | |||
228 | if (ali_settimer(new_timeout)) | ||
229 | return -EINVAL; | ||
230 | |||
231 | ali_keepalive(); | ||
232 | /* Fall */ | ||
233 | } | ||
234 | |||
235 | case WDIOC_GETTIMEOUT: | ||
236 | return put_user(timeout, p); | ||
237 | |||
238 | default: | ||
239 | return -ENOTTY; | ||
240 | } | ||
241 | } | ||
242 | |||
243 | /* | ||
244 | * ali_open - handle open of ali watchdog | ||
245 | * @inode: inode from VFS | ||
246 | * @file: file from VFS | ||
247 | * | ||
248 | * Open the ALi watchdog device. Ensure only one person opens it | ||
249 | * at a time. Also start the watchdog running. | ||
250 | */ | ||
251 | |||
252 | static int ali_open(struct inode *inode, struct file *file) | ||
253 | { | ||
254 | /* /dev/watchdog can only be opened once */ | ||
255 | if (test_and_set_bit(0, &ali_is_open)) | ||
256 | return -EBUSY; | ||
257 | |||
258 | /* Activate */ | ||
259 | ali_start(); | ||
260 | return nonseekable_open(inode, file); | ||
261 | } | ||
262 | |||
263 | /* | ||
264 | * ali_release - close an ALi watchdog | ||
265 | * @inode: inode from VFS | ||
266 | * @file: file from VFS | ||
267 | * | ||
268 | * Close the ALi watchdog device. Actual shutdown of the timer | ||
269 | * only occurs if the magic sequence has been set. | ||
270 | */ | ||
271 | |||
272 | static int ali_release(struct inode *inode, struct file *file) | ||
273 | { | ||
274 | /* | ||
275 | * Shut off the timer. | ||
276 | */ | ||
277 | if (ali_expect_release == 42) { | ||
278 | ali_stop(); | ||
279 | } else { | ||
280 | printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); | ||
281 | ali_keepalive(); | ||
282 | } | ||
283 | clear_bit(0, &ali_is_open); | ||
284 | ali_expect_release = 0; | ||
285 | return 0; | ||
286 | } | ||
287 | |||
288 | /* | ||
289 | * ali_notify_sys - System down notifier | ||
290 | * | ||
291 | * Notifier for system down | ||
292 | */ | ||
293 | |||
294 | |||
295 | static int ali_notify_sys(struct notifier_block *this, unsigned long code, void *unused) | ||
296 | { | ||
297 | if (code==SYS_DOWN || code==SYS_HALT) { | ||
298 | /* Turn the WDT off */ | ||
299 | ali_stop(); | ||
300 | } | ||
301 | |||
302 | return NOTIFY_DONE; | ||
303 | } | ||
304 | |||
305 | /* | ||
306 | * Data for PCI driver interface | ||
307 | * | ||
308 | * This data only exists for exporting the supported | ||
309 | * PCI ids via MODULE_DEVICE_TABLE. We do not actually | ||
310 | * register a pci_driver, because someone else might one day | ||
311 | * want to register another driver on the same PCI id. | ||
312 | */ | ||
313 | |||
314 | static struct pci_device_id ali_pci_tbl[] = { | ||
315 | { PCI_VENDOR_ID_AL, 0x1533, PCI_ANY_ID, PCI_ANY_ID,}, | ||
316 | { PCI_VENDOR_ID_AL, 0x1535, PCI_ANY_ID, PCI_ANY_ID,}, | ||
317 | { 0, }, | ||
318 | }; | ||
319 | MODULE_DEVICE_TABLE(pci, ali_pci_tbl); | ||
320 | |||
321 | /* | ||
322 | * ali_find_watchdog - find a 1535 and 7101 | ||
323 | * | ||
324 | * Scans the PCI hardware for a 1535 series bridge and matching 7101 | ||
325 | * watchdog device. This may be overtight but it is better to be safe | ||
326 | */ | ||
327 | |||
328 | static int __init ali_find_watchdog(void) | ||
329 | { | ||
330 | struct pci_dev *pdev; | ||
331 | u32 wdog; | ||
332 | |||
333 | /* Check for a 1533/1535 series bridge */ | ||
334 | pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1535, NULL); | ||
335 | if (pdev == NULL) | ||
336 | pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1533, NULL); | ||
337 | if (pdev == NULL) | ||
338 | return -ENODEV; | ||
339 | pci_dev_put(pdev); | ||
340 | |||
341 | /* Check for the a 7101 PMU */ | ||
342 | pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x7101, NULL); | ||
343 | if(pdev == NULL) | ||
344 | return -ENODEV; | ||
345 | |||
346 | if(pci_enable_device(pdev)) { | ||
347 | pci_dev_put(pdev); | ||
348 | return -EIO; | ||
349 | } | ||
350 | |||
351 | ali_pci = pdev; | ||
352 | |||
353 | /* | ||
354 | * Initialize the timer bits | ||
355 | */ | ||
356 | pci_read_config_dword(pdev, 0xCC, &wdog); | ||
357 | |||
358 | wdog &= ~0x3F; /* Timer bits */ | ||
359 | wdog &= ~((1<<27)|(1<<26)|(1<<25)|(1<<24)); /* Issued events */ | ||
360 | wdog &= ~((1<<16)|(1<<13)|(1<<12)|(1<<11)|(1<<10)|(1<<9)); /* No monitor bits */ | ||
361 | |||
362 | pci_write_config_dword(pdev, 0xCC, wdog); | ||
363 | |||
364 | return 0; | ||
365 | } | ||
366 | |||
367 | /* | ||
368 | * Kernel Interfaces | ||
369 | */ | ||
370 | |||
371 | static const struct file_operations ali_fops = { | ||
372 | .owner = THIS_MODULE, | ||
373 | .llseek = no_llseek, | ||
374 | .write = ali_write, | ||
375 | .ioctl = ali_ioctl, | ||
376 | .open = ali_open, | ||
377 | .release = ali_release, | ||
378 | }; | ||
379 | |||
380 | static struct miscdevice ali_miscdev = { | ||
381 | .minor = WATCHDOG_MINOR, | ||
382 | .name = "watchdog", | ||
383 | .fops = &ali_fops, | ||
384 | }; | ||
385 | |||
386 | static struct notifier_block ali_notifier = { | ||
387 | .notifier_call = ali_notify_sys, | ||
388 | }; | ||
389 | |||
390 | /* | ||
391 | * watchdog_init - module initialiser | ||
392 | * | ||
393 | * Scan for a suitable watchdog and if so initialize it. Return an error | ||
394 | * if we cannot, the error causes the module to unload | ||
395 | */ | ||
396 | |||
397 | static int __init watchdog_init(void) | ||
398 | { | ||
399 | int ret; | ||
400 | |||
401 | spin_lock_init(&ali_lock); | ||
402 | |||
403 | /* Check whether or not the hardware watchdog is there */ | ||
404 | if (ali_find_watchdog() != 0) { | ||
405 | return -ENODEV; | ||
406 | } | ||
407 | |||
408 | /* Check that the timeout value is within it's range ; if not reset to the default */ | ||
409 | if (timeout < 1 || timeout >= 18000) { | ||
410 | timeout = WATCHDOG_TIMEOUT; | ||
411 | printk(KERN_INFO PFX "timeout value must be 0<timeout<18000, using %d\n", | ||
412 | timeout); | ||
413 | } | ||
414 | |||
415 | /* Calculate the watchdog's timeout */ | ||
416 | ali_settimer(timeout); | ||
417 | |||
418 | ret = misc_register(&ali_miscdev); | ||
419 | if (ret != 0) { | ||
420 | printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | ||
421 | WATCHDOG_MINOR, ret); | ||
422 | goto out; | ||
423 | } | ||
424 | |||
425 | ret = register_reboot_notifier(&ali_notifier); | ||
426 | if (ret != 0) { | ||
427 | printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", | ||
428 | ret); | ||
429 | goto unreg_miscdev; | ||
430 | } | ||
431 | |||
432 | printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", | ||
433 | timeout, nowayout); | ||
434 | |||
435 | out: | ||
436 | return ret; | ||
437 | unreg_miscdev: | ||
438 | misc_deregister(&ali_miscdev); | ||
439 | goto out; | ||
440 | } | ||
441 | |||
442 | /* | ||
443 | * watchdog_exit - module de-initialiser | ||
444 | * | ||
445 | * Called while unloading a successfully installed watchdog module. | ||
446 | */ | ||
447 | |||
448 | static void __exit watchdog_exit(void) | ||
449 | { | ||
450 | /* Stop the timer before we leave */ | ||
451 | ali_stop(); | ||
452 | |||
453 | /* Deregister */ | ||
454 | unregister_reboot_notifier(&ali_notifier); | ||
455 | misc_deregister(&ali_miscdev); | ||
456 | pci_dev_put(ali_pci); | ||
457 | } | ||
458 | |||
459 | module_init(watchdog_init); | ||
460 | module_exit(watchdog_exit); | ||
461 | |||
462 | MODULE_AUTHOR("Alan Cox"); | ||
463 | MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver"); | ||
464 | MODULE_LICENSE("GPL"); | ||
465 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||