diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/watchdog/alim1535_wdt.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/char/watchdog/alim1535_wdt.c')
-rw-r--r-- | drivers/char/watchdog/alim1535_wdt.c | 463 |
1 files changed, 463 insertions, 0 deletions
diff --git a/drivers/char/watchdog/alim1535_wdt.c b/drivers/char/watchdog/alim1535_wdt.c new file mode 100644 index 000000000000..35dcbf8be7d1 --- /dev/null +++ b/drivers/char/watchdog/alim1535_wdt.c | |||
@@ -0,0 +1,463 @@ | |||
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 | #ifdef CONFIG_WATCHDOG_NOWAYOUT | ||
42 | static int nowayout = 1; | ||
43 | #else | ||
44 | static int nowayout = 0; | ||
45 | #endif | ||
46 | |||
47 | module_param(nowayout, int, 0); | ||
48 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); | ||
49 | |||
50 | /* | ||
51 | * ali_start - start watchdog countdown | ||
52 | * | ||
53 | * Starts the timer running providing the timer has a counter | ||
54 | * configuration set. | ||
55 | */ | ||
56 | |||
57 | static void ali_start(void) | ||
58 | { | ||
59 | u32 val; | ||
60 | |||
61 | spin_lock(&ali_lock); | ||
62 | |||
63 | pci_read_config_dword(ali_pci, 0xCC, &val); | ||
64 | val &= ~0x3F; /* Mask count */ | ||
65 | val |= (1<<25) | ali_timeout_bits; | ||
66 | pci_write_config_dword(ali_pci, 0xCC, val); | ||
67 | |||
68 | spin_unlock(&ali_lock); | ||
69 | } | ||
70 | |||
71 | /* | ||
72 | * ali_stop - stop the timer countdown | ||
73 | * | ||
74 | * Stop the ALi watchdog countdown | ||
75 | */ | ||
76 | |||
77 | static void ali_stop(void) | ||
78 | { | ||
79 | u32 val; | ||
80 | |||
81 | spin_lock(&ali_lock); | ||
82 | |||
83 | pci_read_config_dword(ali_pci, 0xCC, &val); | ||
84 | val &= ~0x3F; /* Mask count to zero (disabled) */ | ||
85 | val &= ~(1<<25);/* and for safety mask the reset enable */ | ||
86 | pci_write_config_dword(ali_pci, 0xCC, val); | ||
87 | |||
88 | spin_unlock(&ali_lock); | ||
89 | } | ||
90 | |||
91 | /* | ||
92 | * ali_keepalive - send a keepalive to the watchdog | ||
93 | * | ||
94 | * Send a keepalive to the timer (actually we restart the timer). | ||
95 | */ | ||
96 | |||
97 | static void ali_keepalive(void) | ||
98 | { | ||
99 | ali_start(); | ||
100 | } | ||
101 | |||
102 | /* | ||
103 | * ali_settimer - compute the timer reload value | ||
104 | * @t: time in seconds | ||
105 | * | ||
106 | * Computes the timeout values needed | ||
107 | */ | ||
108 | |||
109 | static int ali_settimer(int t) | ||
110 | { | ||
111 | if(t < 0) | ||
112 | return -EINVAL; | ||
113 | else if(t < 60) | ||
114 | ali_timeout_bits = t|(1<<6); | ||
115 | else if(t < 3600) | ||
116 | ali_timeout_bits = (t/60)|(1<<7); | ||
117 | else if(t < 18000) | ||
118 | ali_timeout_bits = (t/300)|(1<<6)|(1<<7); | ||
119 | else return -EINVAL; | ||
120 | |||
121 | timeout = t; | ||
122 | return 0; | ||
123 | } | ||
124 | |||
125 | /* | ||
126 | * /dev/watchdog handling | ||
127 | */ | ||
128 | |||
129 | /* | ||
130 | * ali_write - writes to ALi watchdog | ||
131 | * @file: file from VFS | ||
132 | * @data: user address of data | ||
133 | * @len: length of data | ||
134 | * @ppos: pointer to the file offset | ||
135 | * | ||
136 | * Handle a write to the ALi watchdog. Writing to the file pings | ||
137 | * the watchdog and resets it. Writing the magic 'V' sequence allows | ||
138 | * the next close to turn off the watchdog. | ||
139 | */ | ||
140 | |||
141 | static ssize_t ali_write(struct file *file, const char __user *data, | ||
142 | size_t len, loff_t * ppos) | ||
143 | { | ||
144 | /* See if we got the magic character 'V' and reload the timer */ | ||
145 | if (len) { | ||
146 | if (!nowayout) { | ||
147 | size_t i; | ||
148 | |||
149 | /* note: just in case someone wrote the magic character | ||
150 | * five months ago... */ | ||
151 | ali_expect_release = 0; | ||
152 | |||
153 | /* scan to see whether or not we got the magic character */ | ||
154 | for (i = 0; i != len; i++) { | ||
155 | char c; | ||
156 | if(get_user(c, data+i)) | ||
157 | return -EFAULT; | ||
158 | if (c == 'V') | ||
159 | ali_expect_release = 42; | ||
160 | } | ||
161 | } | ||
162 | |||
163 | /* someone wrote to us, we should reload the timer */ | ||
164 | ali_start(); | ||
165 | } | ||
166 | return len; | ||
167 | } | ||
168 | |||
169 | /* | ||
170 | * ali_ioctl - handle watchdog ioctls | ||
171 | * @inode: VFS inode | ||
172 | * @file: VFS file pointer | ||
173 | * @cmd: ioctl number | ||
174 | * @arg: arguments to the ioctl | ||
175 | * | ||
176 | * Handle the watchdog ioctls supported by the ALi driver. Really | ||
177 | * we want an extension to enable irq ack monitoring and the like | ||
178 | */ | ||
179 | |||
180 | static int ali_ioctl(struct inode *inode, struct file *file, | ||
181 | unsigned int cmd, unsigned long arg) | ||
182 | { | ||
183 | void __user *argp = (void __user *)arg; | ||
184 | int __user *p = argp; | ||
185 | static struct watchdog_info ident = { | ||
186 | .options = WDIOF_KEEPALIVEPING | | ||
187 | WDIOF_SETTIMEOUT | | ||
188 | WDIOF_MAGICCLOSE, | ||
189 | .firmware_version = 0, | ||
190 | .identity = "ALi M1535 WatchDog Timer", | ||
191 | }; | ||
192 | |||
193 | switch (cmd) { | ||
194 | case WDIOC_GETSUPPORT: | ||
195 | return copy_to_user(argp, &ident, | ||
196 | sizeof (ident)) ? -EFAULT : 0; | ||
197 | |||
198 | case WDIOC_GETSTATUS: | ||
199 | case WDIOC_GETBOOTSTATUS: | ||
200 | return put_user(0, p); | ||
201 | |||
202 | case WDIOC_KEEPALIVE: | ||
203 | ali_keepalive(); | ||
204 | return 0; | ||
205 | |||
206 | case WDIOC_SETOPTIONS: | ||
207 | { | ||
208 | int new_options, retval = -EINVAL; | ||
209 | |||
210 | if (get_user (new_options, p)) | ||
211 | return -EFAULT; | ||
212 | |||
213 | if (new_options & WDIOS_DISABLECARD) { | ||
214 | ali_stop(); | ||
215 | retval = 0; | ||
216 | } | ||
217 | |||
218 | if (new_options & WDIOS_ENABLECARD) { | ||
219 | ali_start(); | ||
220 | retval = 0; | ||
221 | } | ||
222 | |||
223 | return retval; | ||
224 | } | ||
225 | |||
226 | case WDIOC_SETTIMEOUT: | ||
227 | { | ||
228 | int new_timeout; | ||
229 | |||
230 | if (get_user(new_timeout, p)) | ||
231 | return -EFAULT; | ||
232 | |||
233 | if (ali_settimer(new_timeout)) | ||
234 | return -EINVAL; | ||
235 | |||
236 | ali_keepalive(); | ||
237 | /* Fall */ | ||
238 | } | ||
239 | |||
240 | case WDIOC_GETTIMEOUT: | ||
241 | return put_user(timeout, p); | ||
242 | |||
243 | default: | ||
244 | return -ENOIOCTLCMD; | ||
245 | } | ||
246 | } | ||
247 | |||
248 | /* | ||
249 | * ali_open - handle open of ali watchdog | ||
250 | * @inode: inode from VFS | ||
251 | * @file: file from VFS | ||
252 | * | ||
253 | * Open the ALi watchdog device. Ensure only one person opens it | ||
254 | * at a time. Also start the watchdog running. | ||
255 | */ | ||
256 | |||
257 | static int ali_open(struct inode *inode, struct file *file) | ||
258 | { | ||
259 | /* /dev/watchdog can only be opened once */ | ||
260 | if (test_and_set_bit(0, &ali_is_open)) | ||
261 | return -EBUSY; | ||
262 | |||
263 | /* Activate */ | ||
264 | ali_start(); | ||
265 | return nonseekable_open(inode, file); | ||
266 | } | ||
267 | |||
268 | /* | ||
269 | * ali_release - close an ALi watchdog | ||
270 | * @inode: inode from VFS | ||
271 | * @file: file from VFS | ||
272 | * | ||
273 | * Close the ALi watchdog device. Actual shutdown of the timer | ||
274 | * only occurs if the magic sequence has been set. | ||
275 | */ | ||
276 | |||
277 | static int ali_release(struct inode *inode, struct file *file) | ||
278 | { | ||
279 | /* | ||
280 | * Shut off the timer. | ||
281 | */ | ||
282 | if (ali_expect_release == 42) { | ||
283 | ali_stop(); | ||
284 | } else { | ||
285 | printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); | ||
286 | ali_keepalive(); | ||
287 | } | ||
288 | clear_bit(0, &ali_is_open); | ||
289 | ali_expect_release = 0; | ||
290 | return 0; | ||
291 | } | ||
292 | |||
293 | /* | ||
294 | * ali_notify_sys - System down notifier | ||
295 | * | ||
296 | * Notifier for system down | ||
297 | */ | ||
298 | |||
299 | |||
300 | static int ali_notify_sys(struct notifier_block *this, unsigned long code, void *unused) | ||
301 | { | ||
302 | if (code==SYS_DOWN || code==SYS_HALT) { | ||
303 | /* Turn the WDT off */ | ||
304 | ali_stop(); | ||
305 | } | ||
306 | |||
307 | return NOTIFY_DONE; | ||
308 | } | ||
309 | |||
310 | /* | ||
311 | * Data for PCI driver interface | ||
312 | * | ||
313 | * This data only exists for exporting the supported | ||
314 | * PCI ids via MODULE_DEVICE_TABLE. We do not actually | ||
315 | * register a pci_driver, because someone else might one day | ||
316 | * want to register another driver on the same PCI id. | ||
317 | */ | ||
318 | |||
319 | static struct pci_device_id ali_pci_tbl[] = { | ||
320 | { PCI_VENDOR_ID_AL, 1535, PCI_ANY_ID, PCI_ANY_ID,}, | ||
321 | { 0, }, | ||
322 | }; | ||
323 | MODULE_DEVICE_TABLE(pci, ali_pci_tbl); | ||
324 | |||
325 | /* | ||
326 | * ali_find_watchdog - find a 1535 and 7101 | ||
327 | * | ||
328 | * Scans the PCI hardware for a 1535 series bridge and matching 7101 | ||
329 | * watchdog device. This may be overtight but it is better to be safe | ||
330 | */ | ||
331 | |||
332 | static int __init ali_find_watchdog(void) | ||
333 | { | ||
334 | struct pci_dev *pdev; | ||
335 | u32 wdog; | ||
336 | |||
337 | /* Check for a 1535 series bridge */ | ||
338 | pdev = pci_find_device(PCI_VENDOR_ID_AL, 0x1535, NULL); | ||
339 | if(pdev == NULL) | ||
340 | return -ENODEV; | ||
341 | |||
342 | /* Check for the a 7101 PMU */ | ||
343 | pdev = pci_find_device(PCI_VENDOR_ID_AL, 0x7101, NULL); | ||
344 | if(pdev == NULL) | ||
345 | return -ENODEV; | ||
346 | |||
347 | if(pci_enable_device(pdev)) | ||
348 | return -EIO; | ||
349 | |||
350 | ali_pci = pdev; | ||
351 | |||
352 | /* | ||
353 | * Initialize the timer bits | ||
354 | */ | ||
355 | pci_read_config_dword(pdev, 0xCC, &wdog); | ||
356 | |||
357 | wdog &= ~0x3F; /* Timer bits */ | ||
358 | wdog &= ~((1<<27)|(1<<26)|(1<<25)|(1<<24)); /* Issued events */ | ||
359 | wdog &= ~((1<<16)|(1<<13)|(1<<12)|(1<<11)|(1<<10)|(1<<9)); /* No monitor bits */ | ||
360 | |||
361 | pci_write_config_dword(pdev, 0xCC, wdog); | ||
362 | |||
363 | return 0; | ||
364 | } | ||
365 | |||
366 | /* | ||
367 | * Kernel Interfaces | ||
368 | */ | ||
369 | |||
370 | static struct file_operations ali_fops = { | ||
371 | .owner = THIS_MODULE, | ||
372 | .llseek = no_llseek, | ||
373 | .write = ali_write, | ||
374 | .ioctl = ali_ioctl, | ||
375 | .open = ali_open, | ||
376 | .release = ali_release, | ||
377 | }; | ||
378 | |||
379 | static struct miscdevice ali_miscdev = { | ||
380 | .minor = WATCHDOG_MINOR, | ||
381 | .name = "watchdog", | ||
382 | .fops = &ali_fops, | ||
383 | }; | ||
384 | |||
385 | static struct notifier_block ali_notifier = { | ||
386 | .notifier_call = ali_notify_sys, | ||
387 | }; | ||
388 | |||
389 | /* | ||
390 | * watchdog_init - module initialiser | ||
391 | * | ||
392 | * Scan for a suitable watchdog and if so initialize it. Return an error | ||
393 | * if we cannot, the error causes the module to unload | ||
394 | */ | ||
395 | |||
396 | static int __init watchdog_init(void) | ||
397 | { | ||
398 | int ret; | ||
399 | |||
400 | spin_lock_init(&ali_lock); | ||
401 | |||
402 | /* Check whether or not the hardware watchdog is there */ | ||
403 | if (ali_find_watchdog() != 0) { | ||
404 | return -ENODEV; | ||
405 | } | ||
406 | |||
407 | /* Check that the timeout value is within it's range ; if not reset to the default */ | ||
408 | if (timeout < 1 || timeout >= 18000) { | ||
409 | timeout = WATCHDOG_TIMEOUT; | ||
410 | printk(KERN_INFO PFX "timeout value must be 0<timeout<18000, using %d\n", | ||
411 | timeout); | ||
412 | } | ||
413 | |||
414 | /* Calculate the watchdog's timeout */ | ||
415 | ali_settimer(timeout); | ||
416 | |||
417 | ret = misc_register(&ali_miscdev); | ||
418 | if (ret != 0) { | ||
419 | printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | ||
420 | WATCHDOG_MINOR, ret); | ||
421 | goto out; | ||
422 | } | ||
423 | |||
424 | ret = register_reboot_notifier(&ali_notifier); | ||
425 | if (ret != 0) { | ||
426 | printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", | ||
427 | ret); | ||
428 | goto unreg_miscdev; | ||
429 | } | ||
430 | |||
431 | printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", | ||
432 | timeout, nowayout); | ||
433 | |||
434 | out: | ||
435 | return ret; | ||
436 | unreg_miscdev: | ||
437 | misc_deregister(&ali_miscdev); | ||
438 | goto out; | ||
439 | } | ||
440 | |||
441 | /* | ||
442 | * watchdog_exit - module de-initialiser | ||
443 | * | ||
444 | * Called while unloading a successfully installed watchdog module. | ||
445 | */ | ||
446 | |||
447 | static void __exit watchdog_exit(void) | ||
448 | { | ||
449 | /* Stop the timer before we leave */ | ||
450 | ali_stop(); | ||
451 | |||
452 | /* Deregister */ | ||
453 | unregister_reboot_notifier(&ali_notifier); | ||
454 | misc_deregister(&ali_miscdev); | ||
455 | } | ||
456 | |||
457 | module_init(watchdog_init); | ||
458 | module_exit(watchdog_exit); | ||
459 | |||
460 | MODULE_AUTHOR("Alan Cox"); | ||
461 | MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver"); | ||
462 | MODULE_LICENSE("GPL"); | ||
463 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||