Commit | Line | Data |
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1da177e4 LT |
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 | ||
4bfdf378 | 41 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 | 42 | module_param(nowayout, int, 0); |
bffda5c8 | 43 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
1da177e4 LT |
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: | |
795b89d2 | 239 | return -ENOTTY; |
1da177e4 LT |
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[] = { | |
6e420b7e | 315 | { PCI_VENDOR_ID_AL, 0x1533, PCI_ANY_ID, PCI_ANY_ID,}, |
b7343f01 | 316 | { PCI_VENDOR_ID_AL, 0x1535, PCI_ANY_ID, PCI_ANY_ID,}, |
1da177e4 LT |
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 | ||
6e420b7e | 333 | /* Check for a 1533/1535 series bridge */ |
02be2ee9 | 334 | pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1535, NULL); |
6e420b7e AB |
335 | if (pdev == NULL) |
336 | pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1533, NULL); | |
337 | if (pdev == NULL) | |
1da177e4 | 338 | return -ENODEV; |
02be2ee9 | 339 | pci_dev_put(pdev); |
1da177e4 LT |
340 | |
341 | /* Check for the a 7101 PMU */ | |
02be2ee9 | 342 | pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x7101, NULL); |
1da177e4 LT |
343 | if(pdev == NULL) |
344 | return -ENODEV; | |
345 | ||
02be2ee9 JS |
346 | if(pci_enable_device(pdev)) { |
347 | pci_dev_put(pdev); | |
1da177e4 | 348 | return -EIO; |
02be2ee9 | 349 | } |
1da177e4 LT |
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 | ||
62322d25 | 371 | static const struct file_operations ali_fops = { |
1da177e4 LT |
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); | |
02be2ee9 | 456 | pci_dev_put(ali_pci); |
1da177e4 LT |
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); |