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1da177e4 LT |
1 | /* |
2 | * ALi M7101 PMU Computer Watchdog Timer driver | |
3 | * | |
4 | * Based on w83877f_wdt.c by Scott Jennings <linuxdrivers@oro.net> | |
5 | * and the Cobalt kernel WDT timer driver by Tim Hockin | |
6 | * <thockin@cobaltnet.com> | |
7 | * | |
8 | * (c)2002 Steve Hill <steve@navaho.co.uk> | |
9 | * | |
10 | * This WDT driver is different from most other Linux WDT | |
11 | * drivers in that the driver will ping the watchdog by itself, | |
12 | * because this particular WDT has a very short timeout (1.6 | |
13 | * seconds) and it would be insane to count on any userspace | |
14 | * daemon always getting scheduled within that time frame. | |
15 | * | |
16 | * Additions: | |
17 | * Aug 23, 2004 - Added use_gpio module parameter for use on revision a1d PMUs | |
18 | * found on very old cobalt hardware. | |
19 | * -- Mike Waychison <michael.waychison@sun.com> | |
20 | */ | |
21 | ||
22 | #include <linux/module.h> | |
23 | #include <linux/moduleparam.h> | |
24 | #include <linux/types.h> | |
25 | #include <linux/timer.h> | |
26 | #include <linux/miscdevice.h> | |
27 | #include <linux/watchdog.h> | |
28 | #include <linux/ioport.h> | |
29 | #include <linux/notifier.h> | |
30 | #include <linux/reboot.h> | |
31 | #include <linux/init.h> | |
32 | #include <linux/fs.h> | |
33 | #include <linux/pci.h> | |
34 | ||
35 | #include <asm/io.h> | |
36 | #include <asm/uaccess.h> | |
37 | #include <asm/system.h> | |
38 | ||
39 | #define OUR_NAME "alim7101_wdt" | |
40 | #define PFX OUR_NAME ": " | |
41 | ||
42 | #define WDT_ENABLE 0x9C | |
43 | #define WDT_DISABLE 0x8C | |
44 | ||
45 | #define ALI_7101_WDT 0x92 | |
46 | #define ALI_7101_GPIO 0x7D | |
47 | #define ALI_7101_GPIO_O 0x7E | |
48 | #define ALI_WDT_ARM 0x01 | |
49 | ||
50 | /* | |
51 | * We're going to use a 1 second timeout. | |
52 | * If we reset the watchdog every ~250ms we should be safe. */ | |
53 | ||
54 | #define WDT_INTERVAL (HZ/4+1) | |
55 | ||
56 | /* | |
57 | * We must not require too good response from the userspace daemon. | |
58 | * Here we require the userspace daemon to send us a heartbeat | |
59 | * char to /dev/watchdog every 30 seconds. | |
60 | */ | |
61 | ||
62 | #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ | |
63 | static int timeout = WATCHDOG_TIMEOUT; /* in seconds, will be multiplied by HZ to get seconds to wait for a ping */ | |
64 | module_param(timeout, int, 0); | |
65 | MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); | |
66 | ||
67 | static int use_gpio = 0; /* Use the pic (for a1d revision alim7101) */ | |
68 | module_param(use_gpio, int, 0); | |
69 | MODULE_PARM_DESC(use_gpio, "Use the gpio watchdog. (required by old cobalt boards)"); | |
70 | ||
71 | static void wdt_timer_ping(unsigned long); | |
72 | static struct timer_list timer; | |
73 | static unsigned long next_heartbeat; | |
74 | static unsigned long wdt_is_open; | |
75 | static char wdt_expect_close; | |
76 | static struct pci_dev *alim7101_pmu; | |
77 | ||
4bfdf378 | 78 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 | 79 | module_param(nowayout, int, 0); |
5cacb9f8 BC |
80 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
81 | __stringify(CONFIG_WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
82 | |
83 | /* | |
84 | * Whack the dog | |
85 | */ | |
86 | ||
87 | static void wdt_timer_ping(unsigned long data) | |
88 | { | |
89 | /* If we got a heartbeat pulse within the WDT_US_INTERVAL | |
90 | * we agree to ping the WDT | |
91 | */ | |
92 | char tmp; | |
93 | ||
94 | if(time_before(jiffies, next_heartbeat)) | |
95 | { | |
96 | /* Ping the WDT (this is actually a disarm/arm sequence) */ | |
97 | pci_read_config_byte(alim7101_pmu, 0x92, &tmp); | |
98 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp & ~ALI_WDT_ARM)); | |
99 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp | ALI_WDT_ARM)); | |
100 | if (use_gpio) { | |
101 | pci_read_config_byte(alim7101_pmu, ALI_7101_GPIO_O, &tmp); | |
102 | pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp | |
103 | | 0x20); | |
104 | pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp | |
105 | & ~0x20); | |
106 | } | |
107 | } else { | |
108 | printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n"); | |
109 | } | |
110 | /* Re-set the timer interval */ | |
111 | timer.expires = jiffies + WDT_INTERVAL; | |
112 | add_timer(&timer); | |
113 | } | |
114 | ||
115 | /* | |
116 | * Utility routines | |
117 | */ | |
118 | ||
119 | static void wdt_change(int writeval) | |
120 | { | |
121 | char tmp; | |
122 | ||
123 | pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp); | |
124 | if (writeval == WDT_ENABLE) { | |
125 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp | ALI_WDT_ARM)); | |
126 | if (use_gpio) { | |
127 | pci_read_config_byte(alim7101_pmu, ALI_7101_GPIO_O, &tmp); | |
128 | pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp & ~0x20); | |
129 | } | |
130 | ||
131 | } else { | |
132 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp & ~ALI_WDT_ARM)); | |
133 | if (use_gpio) { | |
134 | pci_read_config_byte(alim7101_pmu, ALI_7101_GPIO_O, &tmp); | |
135 | pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp | 0x20); | |
136 | } | |
137 | } | |
138 | } | |
139 | ||
140 | static void wdt_startup(void) | |
141 | { | |
142 | next_heartbeat = jiffies + (timeout * HZ); | |
143 | ||
144 | /* We must enable before we kick off the timer in case the timer | |
145 | occurs as we ping it */ | |
146 | ||
147 | wdt_change(WDT_ENABLE); | |
148 | ||
149 | /* Start the timer */ | |
150 | timer.expires = jiffies + WDT_INTERVAL; | |
151 | add_timer(&timer); | |
152 | ||
153 | ||
154 | printk(KERN_INFO PFX "Watchdog timer is now enabled.\n"); | |
155 | } | |
156 | ||
157 | static void wdt_turnoff(void) | |
158 | { | |
159 | /* Stop the timer */ | |
160 | del_timer_sync(&timer); | |
161 | wdt_change(WDT_DISABLE); | |
162 | printk(KERN_INFO PFX "Watchdog timer is now disabled...\n"); | |
163 | } | |
164 | ||
165 | static void wdt_keepalive(void) | |
166 | { | |
167 | /* user land ping */ | |
168 | next_heartbeat = jiffies + (timeout * HZ); | |
169 | } | |
170 | ||
171 | /* | |
172 | * /dev/watchdog handling | |
173 | */ | |
174 | ||
175 | static ssize_t fop_write(struct file * file, const char __user * buf, size_t count, loff_t * ppos) | |
176 | { | |
177 | /* See if we got the magic character 'V' and reload the timer */ | |
178 | if(count) { | |
179 | if (!nowayout) { | |
180 | size_t ofs; | |
181 | ||
182 | /* note: just in case someone wrote the magic character | |
183 | * five months ago... */ | |
184 | wdt_expect_close = 0; | |
185 | ||
186 | /* now scan */ | |
187 | for (ofs = 0; ofs != count; ofs++) { | |
188 | char c; | |
189 | if (get_user(c, buf+ofs)) | |
190 | return -EFAULT; | |
191 | if (c == 'V') | |
192 | wdt_expect_close = 42; | |
193 | } | |
194 | } | |
195 | /* someone wrote to us, we should restart timer */ | |
196 | wdt_keepalive(); | |
197 | } | |
198 | return count; | |
199 | } | |
200 | ||
201 | static int fop_open(struct inode * inode, struct file * file) | |
202 | { | |
203 | /* Just in case we're already talking to someone... */ | |
204 | if(test_and_set_bit(0, &wdt_is_open)) | |
205 | return -EBUSY; | |
206 | /* Good, fire up the show */ | |
207 | wdt_startup(); | |
208 | return nonseekable_open(inode, file); | |
209 | } | |
210 | ||
211 | static int fop_close(struct inode * inode, struct file * file) | |
212 | { | |
213 | if(wdt_expect_close == 42) | |
214 | wdt_turnoff(); | |
215 | else { | |
216 | /* wim: shouldn't there be a: del_timer(&timer); */ | |
217 | printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n"); | |
218 | } | |
219 | clear_bit(0, &wdt_is_open); | |
220 | wdt_expect_close = 0; | |
221 | return 0; | |
222 | } | |
223 | ||
224 | static int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) | |
225 | { | |
226 | void __user *argp = (void __user *)arg; | |
227 | int __user *p = argp; | |
228 | static struct watchdog_info ident = | |
229 | { | |
230 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, | |
231 | .firmware_version = 1, | |
232 | .identity = "ALiM7101", | |
233 | }; | |
234 | ||
235 | switch(cmd) | |
236 | { | |
237 | case WDIOC_GETSUPPORT: | |
238 | return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0; | |
239 | case WDIOC_GETSTATUS: | |
240 | case WDIOC_GETBOOTSTATUS: | |
241 | return put_user(0, p); | |
242 | case WDIOC_KEEPALIVE: | |
243 | wdt_keepalive(); | |
244 | return 0; | |
245 | case WDIOC_SETOPTIONS: | |
246 | { | |
247 | int new_options, retval = -EINVAL; | |
248 | ||
249 | if(get_user(new_options, p)) | |
250 | return -EFAULT; | |
251 | ||
252 | if(new_options & WDIOS_DISABLECARD) { | |
253 | wdt_turnoff(); | |
254 | retval = 0; | |
255 | } | |
256 | ||
257 | if(new_options & WDIOS_ENABLECARD) { | |
258 | wdt_startup(); | |
259 | retval = 0; | |
260 | } | |
261 | ||
262 | return retval; | |
263 | } | |
264 | case WDIOC_SETTIMEOUT: | |
265 | { | |
266 | int new_timeout; | |
267 | ||
268 | if(get_user(new_timeout, p)) | |
269 | return -EFAULT; | |
270 | ||
271 | if(new_timeout < 1 || new_timeout > 3600) /* arbitrary upper limit */ | |
272 | return -EINVAL; | |
273 | ||
274 | timeout = new_timeout; | |
275 | wdt_keepalive(); | |
276 | /* Fall through */ | |
277 | } | |
278 | case WDIOC_GETTIMEOUT: | |
279 | return put_user(timeout, p); | |
280 | default: | |
795b89d2 | 281 | return -ENOTTY; |
1da177e4 LT |
282 | } |
283 | } | |
284 | ||
62322d25 | 285 | static const struct file_operations wdt_fops = { |
1da177e4 LT |
286 | .owner= THIS_MODULE, |
287 | .llseek= no_llseek, | |
288 | .write= fop_write, | |
289 | .open= fop_open, | |
290 | .release= fop_close, | |
291 | .ioctl= fop_ioctl, | |
292 | }; | |
293 | ||
294 | static struct miscdevice wdt_miscdev = { | |
295 | .minor=WATCHDOG_MINOR, | |
296 | .name="watchdog", | |
297 | .fops=&wdt_fops, | |
298 | }; | |
299 | ||
300 | /* | |
301 | * Notifier for system down | |
302 | */ | |
303 | ||
304 | static int wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) | |
305 | { | |
306 | if (code==SYS_DOWN || code==SYS_HALT) | |
307 | wdt_turnoff(); | |
308 | ||
309 | if (code==SYS_RESTART) { | |
310 | /* | |
311 | * Cobalt devices have no way of rebooting themselves other than | |
312 | * getting the watchdog to pull reset, so we restart the watchdog on | |
313 | * reboot with no heartbeat | |
314 | */ | |
315 | wdt_change(WDT_ENABLE); | |
316 | printk(KERN_INFO PFX "Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second.\n"); | |
317 | } | |
318 | return NOTIFY_DONE; | |
319 | } | |
320 | ||
321 | /* | |
322 | * The WDT needs to learn about soft shutdowns in order to | |
323 | * turn the timebomb registers off. | |
324 | */ | |
325 | ||
326 | static struct notifier_block wdt_notifier= | |
327 | { | |
328 | .notifier_call = wdt_notify_sys, | |
329 | }; | |
330 | ||
331 | static void __exit alim7101_wdt_unload(void) | |
332 | { | |
333 | wdt_turnoff(); | |
334 | /* Deregister */ | |
335 | misc_deregister(&wdt_miscdev); | |
336 | unregister_reboot_notifier(&wdt_notifier); | |
02be2ee9 | 337 | pci_dev_put(alim7101_pmu); |
1da177e4 LT |
338 | } |
339 | ||
340 | static int __init alim7101_wdt_init(void) | |
341 | { | |
342 | int rc = -EBUSY; | |
343 | struct pci_dev *ali1543_south; | |
344 | char tmp; | |
345 | ||
346 | printk(KERN_INFO PFX "Steve Hill <steve@navaho.co.uk>.\n"); | |
02be2ee9 JS |
347 | alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101, |
348 | NULL); | |
1da177e4 LT |
349 | if (!alim7101_pmu) { |
350 | printk(KERN_INFO PFX "ALi M7101 PMU not present - WDT not set\n"); | |
351 | return -EBUSY; | |
352 | } | |
353 | ||
354 | /* Set the WDT in the PMU to 1 second */ | |
355 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02); | |
356 | ||
02be2ee9 JS |
357 | ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, |
358 | NULL); | |
1da177e4 LT |
359 | if (!ali1543_south) { |
360 | printk(KERN_INFO PFX "ALi 1543 South-Bridge not present - WDT not set\n"); | |
02be2ee9 | 361 | goto err_out; |
1da177e4 LT |
362 | } |
363 | pci_read_config_byte(ali1543_south, 0x5e, &tmp); | |
02be2ee9 | 364 | pci_dev_put(ali1543_south); |
1da177e4 LT |
365 | if ((tmp & 0x1e) == 0x00) { |
366 | if (!use_gpio) { | |
367 | printk(KERN_INFO PFX "Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n"); | |
02be2ee9 | 368 | goto err_out; |
1da177e4 LT |
369 | } |
370 | nowayout = 1; | |
371 | } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) { | |
372 | printk(KERN_INFO PFX "ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n"); | |
02be2ee9 | 373 | goto err_out; |
1da177e4 LT |
374 | } |
375 | ||
376 | if(timeout < 1 || timeout > 3600) /* arbitrary upper limit */ | |
377 | { | |
378 | timeout = WATCHDOG_TIMEOUT; | |
379 | printk(KERN_INFO PFX "timeout value must be 1<=x<=3600, using %d\n", | |
380 | timeout); | |
381 | } | |
382 | ||
383 | init_timer(&timer); | |
384 | timer.function = wdt_timer_ping; | |
385 | timer.data = 1; | |
386 | ||
387 | rc = misc_register(&wdt_miscdev); | |
388 | if (rc) { | |
389 | printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | |
390 | wdt_miscdev.minor, rc); | |
391 | goto err_out; | |
392 | } | |
393 | ||
394 | rc = register_reboot_notifier(&wdt_notifier); | |
395 | if (rc) { | |
396 | printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", | |
397 | rc); | |
398 | goto err_out_miscdev; | |
399 | } | |
400 | ||
401 | if (nowayout) { | |
402 | __module_get(THIS_MODULE); | |
403 | } | |
404 | ||
405 | printk(KERN_INFO PFX "WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n", | |
406 | timeout, nowayout); | |
407 | return 0; | |
408 | ||
409 | err_out_miscdev: | |
410 | misc_deregister(&wdt_miscdev); | |
411 | err_out: | |
02be2ee9 | 412 | pci_dev_put(alim7101_pmu); |
1da177e4 LT |
413 | return rc; |
414 | } | |
415 | ||
416 | module_init(alim7101_wdt_init); | |
417 | module_exit(alim7101_wdt_unload); | |
418 | ||
5cacb9f8 BC |
419 | static struct pci_device_id alim7101_pci_tbl[] __devinitdata = { |
420 | { PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, | |
421 | PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, | |
422 | { PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101, | |
423 | PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0}, | |
424 | { } | |
425 | }; | |
426 | ||
427 | MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl); | |
428 | ||
1da177e4 LT |
429 | MODULE_AUTHOR("Steve Hill"); |
430 | MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver"); | |
431 | MODULE_LICENSE("GPL"); | |
432 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |