Commit | Line | Data |
---|---|---|
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 LT |
79 | module_param(nowayout, int, 0); |
80 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); | |
81 | ||
82 | /* | |
83 | * Whack the dog | |
84 | */ | |
85 | ||
86 | static void wdt_timer_ping(unsigned long data) | |
87 | { | |
88 | /* If we got a heartbeat pulse within the WDT_US_INTERVAL | |
89 | * we agree to ping the WDT | |
90 | */ | |
91 | char tmp; | |
92 | ||
93 | if(time_before(jiffies, next_heartbeat)) | |
94 | { | |
95 | /* Ping the WDT (this is actually a disarm/arm sequence) */ | |
96 | pci_read_config_byte(alim7101_pmu, 0x92, &tmp); | |
97 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp & ~ALI_WDT_ARM)); | |
98 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp | ALI_WDT_ARM)); | |
99 | if (use_gpio) { | |
100 | pci_read_config_byte(alim7101_pmu, ALI_7101_GPIO_O, &tmp); | |
101 | pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp | |
102 | | 0x20); | |
103 | pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp | |
104 | & ~0x20); | |
105 | } | |
106 | } else { | |
107 | printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n"); | |
108 | } | |
109 | /* Re-set the timer interval */ | |
110 | timer.expires = jiffies + WDT_INTERVAL; | |
111 | add_timer(&timer); | |
112 | } | |
113 | ||
114 | /* | |
115 | * Utility routines | |
116 | */ | |
117 | ||
118 | static void wdt_change(int writeval) | |
119 | { | |
120 | char tmp; | |
121 | ||
122 | pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp); | |
123 | if (writeval == WDT_ENABLE) { | |
124 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp | ALI_WDT_ARM)); | |
125 | if (use_gpio) { | |
126 | pci_read_config_byte(alim7101_pmu, ALI_7101_GPIO_O, &tmp); | |
127 | pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp & ~0x20); | |
128 | } | |
129 | ||
130 | } else { | |
131 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, (tmp & ~ALI_WDT_ARM)); | |
132 | if (use_gpio) { | |
133 | pci_read_config_byte(alim7101_pmu, ALI_7101_GPIO_O, &tmp); | |
134 | pci_write_config_byte(alim7101_pmu, ALI_7101_GPIO_O, tmp | 0x20); | |
135 | } | |
136 | } | |
137 | } | |
138 | ||
139 | static void wdt_startup(void) | |
140 | { | |
141 | next_heartbeat = jiffies + (timeout * HZ); | |
142 | ||
143 | /* We must enable before we kick off the timer in case the timer | |
144 | occurs as we ping it */ | |
145 | ||
146 | wdt_change(WDT_ENABLE); | |
147 | ||
148 | /* Start the timer */ | |
149 | timer.expires = jiffies + WDT_INTERVAL; | |
150 | add_timer(&timer); | |
151 | ||
152 | ||
153 | printk(KERN_INFO PFX "Watchdog timer is now enabled.\n"); | |
154 | } | |
155 | ||
156 | static void wdt_turnoff(void) | |
157 | { | |
158 | /* Stop the timer */ | |
159 | del_timer_sync(&timer); | |
160 | wdt_change(WDT_DISABLE); | |
161 | printk(KERN_INFO PFX "Watchdog timer is now disabled...\n"); | |
162 | } | |
163 | ||
164 | static void wdt_keepalive(void) | |
165 | { | |
166 | /* user land ping */ | |
167 | next_heartbeat = jiffies + (timeout * HZ); | |
168 | } | |
169 | ||
170 | /* | |
171 | * /dev/watchdog handling | |
172 | */ | |
173 | ||
174 | static ssize_t fop_write(struct file * file, const char __user * buf, size_t count, loff_t * ppos) | |
175 | { | |
176 | /* See if we got the magic character 'V' and reload the timer */ | |
177 | if(count) { | |
178 | if (!nowayout) { | |
179 | size_t ofs; | |
180 | ||
181 | /* note: just in case someone wrote the magic character | |
182 | * five months ago... */ | |
183 | wdt_expect_close = 0; | |
184 | ||
185 | /* now scan */ | |
186 | for (ofs = 0; ofs != count; ofs++) { | |
187 | char c; | |
188 | if (get_user(c, buf+ofs)) | |
189 | return -EFAULT; | |
190 | if (c == 'V') | |
191 | wdt_expect_close = 42; | |
192 | } | |
193 | } | |
194 | /* someone wrote to us, we should restart timer */ | |
195 | wdt_keepalive(); | |
196 | } | |
197 | return count; | |
198 | } | |
199 | ||
200 | static int fop_open(struct inode * inode, struct file * file) | |
201 | { | |
202 | /* Just in case we're already talking to someone... */ | |
203 | if(test_and_set_bit(0, &wdt_is_open)) | |
204 | return -EBUSY; | |
205 | /* Good, fire up the show */ | |
206 | wdt_startup(); | |
207 | return nonseekable_open(inode, file); | |
208 | } | |
209 | ||
210 | static int fop_close(struct inode * inode, struct file * file) | |
211 | { | |
212 | if(wdt_expect_close == 42) | |
213 | wdt_turnoff(); | |
214 | else { | |
215 | /* wim: shouldn't there be a: del_timer(&timer); */ | |
216 | printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n"); | |
217 | } | |
218 | clear_bit(0, &wdt_is_open); | |
219 | wdt_expect_close = 0; | |
220 | return 0; | |
221 | } | |
222 | ||
223 | static int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) | |
224 | { | |
225 | void __user *argp = (void __user *)arg; | |
226 | int __user *p = argp; | |
227 | static struct watchdog_info ident = | |
228 | { | |
229 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, | |
230 | .firmware_version = 1, | |
231 | .identity = "ALiM7101", | |
232 | }; | |
233 | ||
234 | switch(cmd) | |
235 | { | |
236 | case WDIOC_GETSUPPORT: | |
237 | return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0; | |
238 | case WDIOC_GETSTATUS: | |
239 | case WDIOC_GETBOOTSTATUS: | |
240 | return put_user(0, p); | |
241 | case WDIOC_KEEPALIVE: | |
242 | wdt_keepalive(); | |
243 | return 0; | |
244 | case WDIOC_SETOPTIONS: | |
245 | { | |
246 | int new_options, retval = -EINVAL; | |
247 | ||
248 | if(get_user(new_options, p)) | |
249 | return -EFAULT; | |
250 | ||
251 | if(new_options & WDIOS_DISABLECARD) { | |
252 | wdt_turnoff(); | |
253 | retval = 0; | |
254 | } | |
255 | ||
256 | if(new_options & WDIOS_ENABLECARD) { | |
257 | wdt_startup(); | |
258 | retval = 0; | |
259 | } | |
260 | ||
261 | return retval; | |
262 | } | |
263 | case WDIOC_SETTIMEOUT: | |
264 | { | |
265 | int new_timeout; | |
266 | ||
267 | if(get_user(new_timeout, p)) | |
268 | return -EFAULT; | |
269 | ||
270 | if(new_timeout < 1 || new_timeout > 3600) /* arbitrary upper limit */ | |
271 | return -EINVAL; | |
272 | ||
273 | timeout = new_timeout; | |
274 | wdt_keepalive(); | |
275 | /* Fall through */ | |
276 | } | |
277 | case WDIOC_GETTIMEOUT: | |
278 | return put_user(timeout, p); | |
279 | default: | |
280 | return -ENOIOCTLCMD; | |
281 | } | |
282 | } | |
283 | ||
62322d25 | 284 | static const struct file_operations wdt_fops = { |
1da177e4 LT |
285 | .owner= THIS_MODULE, |
286 | .llseek= no_llseek, | |
287 | .write= fop_write, | |
288 | .open= fop_open, | |
289 | .release= fop_close, | |
290 | .ioctl= fop_ioctl, | |
291 | }; | |
292 | ||
293 | static struct miscdevice wdt_miscdev = { | |
294 | .minor=WATCHDOG_MINOR, | |
295 | .name="watchdog", | |
296 | .fops=&wdt_fops, | |
297 | }; | |
298 | ||
299 | /* | |
300 | * Notifier for system down | |
301 | */ | |
302 | ||
303 | static int wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) | |
304 | { | |
305 | if (code==SYS_DOWN || code==SYS_HALT) | |
306 | wdt_turnoff(); | |
307 | ||
308 | if (code==SYS_RESTART) { | |
309 | /* | |
310 | * Cobalt devices have no way of rebooting themselves other than | |
311 | * getting the watchdog to pull reset, so we restart the watchdog on | |
312 | * reboot with no heartbeat | |
313 | */ | |
314 | wdt_change(WDT_ENABLE); | |
315 | printk(KERN_INFO PFX "Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second.\n"); | |
316 | } | |
317 | return NOTIFY_DONE; | |
318 | } | |
319 | ||
320 | /* | |
321 | * The WDT needs to learn about soft shutdowns in order to | |
322 | * turn the timebomb registers off. | |
323 | */ | |
324 | ||
325 | static struct notifier_block wdt_notifier= | |
326 | { | |
327 | .notifier_call = wdt_notify_sys, | |
328 | }; | |
329 | ||
330 | static void __exit alim7101_wdt_unload(void) | |
331 | { | |
332 | wdt_turnoff(); | |
333 | /* Deregister */ | |
334 | misc_deregister(&wdt_miscdev); | |
335 | unregister_reboot_notifier(&wdt_notifier); | |
336 | } | |
337 | ||
338 | static int __init alim7101_wdt_init(void) | |
339 | { | |
340 | int rc = -EBUSY; | |
341 | struct pci_dev *ali1543_south; | |
342 | char tmp; | |
343 | ||
344 | printk(KERN_INFO PFX "Steve Hill <steve@navaho.co.uk>.\n"); | |
345 | alim7101_pmu = pci_find_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,NULL); | |
346 | if (!alim7101_pmu) { | |
347 | printk(KERN_INFO PFX "ALi M7101 PMU not present - WDT not set\n"); | |
348 | return -EBUSY; | |
349 | } | |
350 | ||
351 | /* Set the WDT in the PMU to 1 second */ | |
352 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02); | |
353 | ||
354 | ali1543_south = pci_find_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, NULL); | |
355 | if (!ali1543_south) { | |
356 | printk(KERN_INFO PFX "ALi 1543 South-Bridge not present - WDT not set\n"); | |
357 | return -EBUSY; | |
358 | } | |
359 | pci_read_config_byte(ali1543_south, 0x5e, &tmp); | |
360 | if ((tmp & 0x1e) == 0x00) { | |
361 | if (!use_gpio) { | |
362 | printk(KERN_INFO PFX "Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n"); | |
363 | return -EBUSY; | |
364 | } | |
365 | nowayout = 1; | |
366 | } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) { | |
367 | printk(KERN_INFO PFX "ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n"); | |
368 | return -EBUSY; | |
369 | } | |
370 | ||
371 | if(timeout < 1 || timeout > 3600) /* arbitrary upper limit */ | |
372 | { | |
373 | timeout = WATCHDOG_TIMEOUT; | |
374 | printk(KERN_INFO PFX "timeout value must be 1<=x<=3600, using %d\n", | |
375 | timeout); | |
376 | } | |
377 | ||
378 | init_timer(&timer); | |
379 | timer.function = wdt_timer_ping; | |
380 | timer.data = 1; | |
381 | ||
382 | rc = misc_register(&wdt_miscdev); | |
383 | if (rc) { | |
384 | printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | |
385 | wdt_miscdev.minor, rc); | |
386 | goto err_out; | |
387 | } | |
388 | ||
389 | rc = register_reboot_notifier(&wdt_notifier); | |
390 | if (rc) { | |
391 | printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", | |
392 | rc); | |
393 | goto err_out_miscdev; | |
394 | } | |
395 | ||
396 | if (nowayout) { | |
397 | __module_get(THIS_MODULE); | |
398 | } | |
399 | ||
400 | printk(KERN_INFO PFX "WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n", | |
401 | timeout, nowayout); | |
402 | return 0; | |
403 | ||
404 | err_out_miscdev: | |
405 | misc_deregister(&wdt_miscdev); | |
406 | err_out: | |
407 | return rc; | |
408 | } | |
409 | ||
410 | module_init(alim7101_wdt_init); | |
411 | module_exit(alim7101_wdt_unload); | |
412 | ||
413 | MODULE_AUTHOR("Steve Hill"); | |
414 | MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver"); | |
415 | MODULE_LICENSE("GPL"); | |
416 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |