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 | ||
27c766aa JP |
22 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
23 | ||
1da177e4 LT |
24 | #include <linux/module.h> |
25 | #include <linux/moduleparam.h> | |
26 | #include <linux/types.h> | |
27 | #include <linux/timer.h> | |
28 | #include <linux/miscdevice.h> | |
29 | #include <linux/watchdog.h> | |
30 | #include <linux/ioport.h> | |
31 | #include <linux/notifier.h> | |
32 | #include <linux/reboot.h> | |
33 | #include <linux/init.h> | |
34 | #include <linux/fs.h> | |
35 | #include <linux/pci.h> | |
173d95bc AC |
36 | #include <linux/io.h> |
37 | #include <linux/uaccess.h> | |
089ab079 | 38 | |
1da177e4 | 39 | |
1da177e4 LT |
40 | #define WDT_ENABLE 0x9C |
41 | #define WDT_DISABLE 0x8C | |
42 | ||
43 | #define ALI_7101_WDT 0x92 | |
44 | #define ALI_7101_GPIO 0x7D | |
45 | #define ALI_7101_GPIO_O 0x7E | |
46 | #define ALI_WDT_ARM 0x01 | |
47 | ||
48 | /* | |
49 | * We're going to use a 1 second timeout. | |
50 | * If we reset the watchdog every ~250ms we should be safe. */ | |
51 | ||
52 | #define WDT_INTERVAL (HZ/4+1) | |
53 | ||
54 | /* | |
55 | * We must not require too good response from the userspace daemon. | |
56 | * Here we require the userspace daemon to send us a heartbeat | |
57 | * char to /dev/watchdog every 30 seconds. | |
58 | */ | |
59 | ||
60 | #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ | |
173d95bc AC |
61 | /* in seconds, will be multiplied by HZ to get seconds to wait for a ping */ |
62 | static int timeout = WATCHDOG_TIMEOUT; | |
1da177e4 | 63 | module_param(timeout, int, 0); |
173d95bc AC |
64 | MODULE_PARM_DESC(timeout, |
65 | "Watchdog timeout in seconds. (1<=timeout<=3600, default=" | |
66 | __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); | |
1da177e4 | 67 | |
173d95bc | 68 | static int use_gpio; /* Use the pic (for a1d revision alim7101) */ |
1da177e4 | 69 | module_param(use_gpio, int, 0); |
173d95bc AC |
70 | MODULE_PARM_DESC(use_gpio, |
71 | "Use the gpio watchdog (required by old cobalt boards)."); | |
1da177e4 LT |
72 | |
73 | static void wdt_timer_ping(unsigned long); | |
82eb7c50 | 74 | static DEFINE_TIMER(timer, wdt_timer_ping, 0, 1); |
1da177e4 LT |
75 | static unsigned long next_heartbeat; |
76 | static unsigned long wdt_is_open; | |
77 | static char wdt_expect_close; | |
78 | static struct pci_dev *alim7101_pmu; | |
79 | ||
86a1e189 WVS |
80 | static bool nowayout = WATCHDOG_NOWAYOUT; |
81 | module_param(nowayout, bool, 0); | |
173d95bc AC |
82 | MODULE_PARM_DESC(nowayout, |
83 | "Watchdog cannot be stopped once started (default=" | |
84 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
85 | |
86 | /* | |
87 | * Whack the dog | |
88 | */ | |
89 | ||
90 | static void wdt_timer_ping(unsigned long data) | |
91 | { | |
92 | /* If we got a heartbeat pulse within the WDT_US_INTERVAL | |
93 | * we agree to ping the WDT | |
94 | */ | |
173d95bc | 95 | char tmp; |
1da177e4 | 96 | |
173d95bc | 97 | if (time_before(jiffies, next_heartbeat)) { |
1da177e4 LT |
98 | /* Ping the WDT (this is actually a disarm/arm sequence) */ |
99 | pci_read_config_byte(alim7101_pmu, 0x92, &tmp); | |
173d95bc AC |
100 | pci_write_config_byte(alim7101_pmu, |
101 | ALI_7101_WDT, (tmp & ~ALI_WDT_ARM)); | |
102 | pci_write_config_byte(alim7101_pmu, | |
103 | ALI_7101_WDT, (tmp | ALI_WDT_ARM)); | |
1da177e4 | 104 | if (use_gpio) { |
173d95bc AC |
105 | pci_read_config_byte(alim7101_pmu, |
106 | ALI_7101_GPIO_O, &tmp); | |
107 | pci_write_config_byte(alim7101_pmu, | |
108 | ALI_7101_GPIO_O, tmp | 0x20); | |
109 | pci_write_config_byte(alim7101_pmu, | |
110 | ALI_7101_GPIO_O, tmp & ~0x20); | |
1da177e4 LT |
111 | } |
112 | } else { | |
27c766aa | 113 | pr_warn("Heartbeat lost! Will not ping the watchdog\n"); |
1da177e4 LT |
114 | } |
115 | /* Re-set the timer interval */ | |
82eb7c50 | 116 | mod_timer(&timer, jiffies + WDT_INTERVAL); |
1da177e4 LT |
117 | } |
118 | ||
119 | /* | |
120 | * Utility routines | |
121 | */ | |
122 | ||
123 | static void wdt_change(int writeval) | |
124 | { | |
7944d3a5 | 125 | char tmp; |
1da177e4 LT |
126 | |
127 | pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp); | |
128 | if (writeval == WDT_ENABLE) { | |
173d95bc AC |
129 | pci_write_config_byte(alim7101_pmu, |
130 | ALI_7101_WDT, (tmp | ALI_WDT_ARM)); | |
1da177e4 | 131 | if (use_gpio) { |
173d95bc AC |
132 | pci_read_config_byte(alim7101_pmu, |
133 | ALI_7101_GPIO_O, &tmp); | |
134 | pci_write_config_byte(alim7101_pmu, | |
135 | ALI_7101_GPIO_O, tmp & ~0x20); | |
1da177e4 LT |
136 | } |
137 | ||
138 | } else { | |
173d95bc AC |
139 | pci_write_config_byte(alim7101_pmu, |
140 | ALI_7101_WDT, (tmp & ~ALI_WDT_ARM)); | |
1da177e4 | 141 | if (use_gpio) { |
173d95bc AC |
142 | pci_read_config_byte(alim7101_pmu, |
143 | ALI_7101_GPIO_O, &tmp); | |
144 | pci_write_config_byte(alim7101_pmu, | |
145 | ALI_7101_GPIO_O, tmp | 0x20); | |
1da177e4 LT |
146 | } |
147 | } | |
148 | } | |
149 | ||
150 | static void wdt_startup(void) | |
151 | { | |
152 | next_heartbeat = jiffies + (timeout * HZ); | |
153 | ||
154 | /* We must enable before we kick off the timer in case the timer | |
155 | occurs as we ping it */ | |
156 | ||
157 | wdt_change(WDT_ENABLE); | |
158 | ||
159 | /* Start the timer */ | |
82eb7c50 | 160 | mod_timer(&timer, jiffies + WDT_INTERVAL); |
1da177e4 | 161 | |
27c766aa | 162 | pr_info("Watchdog timer is now enabled\n"); |
1da177e4 LT |
163 | } |
164 | ||
165 | static void wdt_turnoff(void) | |
166 | { | |
167 | /* Stop the timer */ | |
168 | del_timer_sync(&timer); | |
169 | wdt_change(WDT_DISABLE); | |
27c766aa | 170 | pr_info("Watchdog timer is now disabled...\n"); |
1da177e4 LT |
171 | } |
172 | ||
173 | static void wdt_keepalive(void) | |
174 | { | |
175 | /* user land ping */ | |
176 | next_heartbeat = jiffies + (timeout * HZ); | |
177 | } | |
178 | ||
179 | /* | |
180 | * /dev/watchdog handling | |
181 | */ | |
182 | ||
173d95bc AC |
183 | static ssize_t fop_write(struct file *file, const char __user *buf, |
184 | size_t count, loff_t *ppos) | |
1da177e4 LT |
185 | { |
186 | /* See if we got the magic character 'V' and reload the timer */ | |
173d95bc | 187 | if (count) { |
1da177e4 LT |
188 | if (!nowayout) { |
189 | size_t ofs; | |
190 | ||
191 | /* note: just in case someone wrote the magic character | |
192 | * five months ago... */ | |
193 | wdt_expect_close = 0; | |
194 | ||
195 | /* now scan */ | |
196 | for (ofs = 0; ofs != count; ofs++) { | |
197 | char c; | |
7944d3a5 | 198 | if (get_user(c, buf + ofs)) |
1da177e4 LT |
199 | return -EFAULT; |
200 | if (c == 'V') | |
201 | wdt_expect_close = 42; | |
202 | } | |
203 | } | |
204 | /* someone wrote to us, we should restart timer */ | |
205 | wdt_keepalive(); | |
206 | } | |
207 | return count; | |
208 | } | |
209 | ||
173d95bc | 210 | static int fop_open(struct inode *inode, struct file *file) |
1da177e4 LT |
211 | { |
212 | /* Just in case we're already talking to someone... */ | |
173d95bc | 213 | if (test_and_set_bit(0, &wdt_is_open)) |
1da177e4 LT |
214 | return -EBUSY; |
215 | /* Good, fire up the show */ | |
216 | wdt_startup(); | |
217 | return nonseekable_open(inode, file); | |
218 | } | |
219 | ||
173d95bc | 220 | static int fop_close(struct inode *inode, struct file *file) |
1da177e4 | 221 | { |
173d95bc | 222 | if (wdt_expect_close == 42) |
1da177e4 LT |
223 | wdt_turnoff(); |
224 | else { | |
225 | /* wim: shouldn't there be a: del_timer(&timer); */ | |
27c766aa | 226 | pr_crit("device file closed unexpectedly. Will not stop the WDT!\n"); |
1da177e4 LT |
227 | } |
228 | clear_bit(0, &wdt_is_open); | |
229 | wdt_expect_close = 0; | |
230 | return 0; | |
231 | } | |
232 | ||
173d95bc | 233 | static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
234 | { |
235 | void __user *argp = (void __user *)arg; | |
236 | int __user *p = argp; | |
42747d71 | 237 | static const struct watchdog_info ident = { |
173d95bc AC |
238 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
239 | | WDIOF_MAGICCLOSE, | |
1da177e4 LT |
240 | .firmware_version = 1, |
241 | .identity = "ALiM7101", | |
242 | }; | |
243 | ||
173d95bc AC |
244 | switch (cmd) { |
245 | case WDIOC_GETSUPPORT: | |
246 | return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; | |
247 | case WDIOC_GETSTATUS: | |
248 | case WDIOC_GETBOOTSTATUS: | |
249 | return put_user(0, p); | |
173d95bc | 250 | case WDIOC_SETOPTIONS: |
1da177e4 | 251 | { |
173d95bc | 252 | int new_options, retval = -EINVAL; |
1da177e4 | 253 | |
173d95bc AC |
254 | if (get_user(new_options, p)) |
255 | return -EFAULT; | |
256 | if (new_options & WDIOS_DISABLECARD) { | |
257 | wdt_turnoff(); | |
258 | retval = 0; | |
1da177e4 | 259 | } |
173d95bc AC |
260 | if (new_options & WDIOS_ENABLECARD) { |
261 | wdt_startup(); | |
262 | retval = 0; | |
1da177e4 | 263 | } |
173d95bc AC |
264 | return retval; |
265 | } | |
0c06090c WVS |
266 | case WDIOC_KEEPALIVE: |
267 | wdt_keepalive(); | |
268 | return 0; | |
173d95bc AC |
269 | case WDIOC_SETTIMEOUT: |
270 | { | |
271 | int new_timeout; | |
272 | ||
273 | if (get_user(new_timeout, p)) | |
274 | return -EFAULT; | |
275 | /* arbitrary upper limit */ | |
276 | if (new_timeout < 1 || new_timeout > 3600) | |
277 | return -EINVAL; | |
278 | timeout = new_timeout; | |
279 | wdt_keepalive(); | |
280 | /* Fall through */ | |
281 | } | |
282 | case WDIOC_GETTIMEOUT: | |
283 | return put_user(timeout, p); | |
284 | default: | |
285 | return -ENOTTY; | |
1da177e4 LT |
286 | } |
287 | } | |
288 | ||
62322d25 | 289 | static const struct file_operations wdt_fops = { |
173d95bc AC |
290 | .owner = THIS_MODULE, |
291 | .llseek = no_llseek, | |
292 | .write = fop_write, | |
293 | .open = fop_open, | |
294 | .release = fop_close, | |
295 | .unlocked_ioctl = fop_ioctl, | |
1da177e4 LT |
296 | }; |
297 | ||
298 | static struct miscdevice wdt_miscdev = { | |
173d95bc AC |
299 | .minor = WATCHDOG_MINOR, |
300 | .name = "watchdog", | |
301 | .fops = &wdt_fops, | |
1da177e4 LT |
302 | }; |
303 | ||
304 | /* | |
305 | * Notifier for system down | |
306 | */ | |
307 | ||
173d95bc AC |
308 | static int wdt_notify_sys(struct notifier_block *this, |
309 | unsigned long code, void *unused) | |
1da177e4 | 310 | { |
173d95bc | 311 | if (code == SYS_DOWN || code == SYS_HALT) |
1da177e4 LT |
312 | wdt_turnoff(); |
313 | ||
173d95bc | 314 | if (code == SYS_RESTART) { |
1da177e4 | 315 | /* |
173d95bc AC |
316 | * Cobalt devices have no way of rebooting themselves other |
317 | * than getting the watchdog to pull reset, so we restart the | |
318 | * watchdog on reboot with no heartbeat | |
1da177e4 LT |
319 | */ |
320 | wdt_change(WDT_ENABLE); | |
27c766aa | 321 | pr_info("Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second\n"); |
1da177e4 LT |
322 | } |
323 | return NOTIFY_DONE; | |
324 | } | |
325 | ||
326 | /* | |
327 | * The WDT needs to learn about soft shutdowns in order to | |
328 | * turn the timebomb registers off. | |
329 | */ | |
330 | ||
173d95bc | 331 | static struct notifier_block wdt_notifier = { |
1da177e4 LT |
332 | .notifier_call = wdt_notify_sys, |
333 | }; | |
334 | ||
335 | static void __exit alim7101_wdt_unload(void) | |
336 | { | |
337 | wdt_turnoff(); | |
338 | /* Deregister */ | |
339 | misc_deregister(&wdt_miscdev); | |
340 | unregister_reboot_notifier(&wdt_notifier); | |
02be2ee9 | 341 | pci_dev_put(alim7101_pmu); |
1da177e4 LT |
342 | } |
343 | ||
344 | static int __init alim7101_wdt_init(void) | |
345 | { | |
346 | int rc = -EBUSY; | |
347 | struct pci_dev *ali1543_south; | |
348 | char tmp; | |
349 | ||
27c766aa | 350 | pr_info("Steve Hill <steve@navaho.co.uk>\n"); |
02be2ee9 JS |
351 | alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101, |
352 | NULL); | |
1da177e4 | 353 | if (!alim7101_pmu) { |
27c766aa | 354 | pr_info("ALi M7101 PMU not present - WDT not set\n"); |
1da177e4 LT |
355 | return -EBUSY; |
356 | } | |
357 | ||
358 | /* Set the WDT in the PMU to 1 second */ | |
359 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02); | |
360 | ||
02be2ee9 JS |
361 | ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, |
362 | NULL); | |
1da177e4 | 363 | if (!ali1543_south) { |
27c766aa | 364 | pr_info("ALi 1543 South-Bridge not present - WDT not set\n"); |
02be2ee9 | 365 | goto err_out; |
1da177e4 LT |
366 | } |
367 | pci_read_config_byte(ali1543_south, 0x5e, &tmp); | |
02be2ee9 | 368 | pci_dev_put(ali1543_south); |
1da177e4 LT |
369 | if ((tmp & 0x1e) == 0x00) { |
370 | if (!use_gpio) { | |
27c766aa | 371 | pr_info("Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n"); |
02be2ee9 | 372 | goto err_out; |
173d95bc | 373 | } |
1da177e4 LT |
374 | nowayout = 1; |
375 | } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) { | |
27c766aa | 376 | pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n"); |
02be2ee9 | 377 | goto err_out; |
1da177e4 LT |
378 | } |
379 | ||
173d95bc AC |
380 | if (timeout < 1 || timeout > 3600) { |
381 | /* arbitrary upper limit */ | |
1da177e4 | 382 | timeout = WATCHDOG_TIMEOUT; |
27c766aa JP |
383 | pr_info("timeout value must be 1 <= x <= 3600, using %d\n", |
384 | timeout); | |
1da177e4 LT |
385 | } |
386 | ||
c6cb13ae | 387 | rc = register_reboot_notifier(&wdt_notifier); |
1da177e4 | 388 | if (rc) { |
27c766aa | 389 | pr_err("cannot register reboot notifier (err=%d)\n", rc); |
1da177e4 LT |
390 | goto err_out; |
391 | } | |
392 | ||
c6cb13ae | 393 | rc = misc_register(&wdt_miscdev); |
1da177e4 | 394 | if (rc) { |
27c766aa JP |
395 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
396 | wdt_miscdev.minor, rc); | |
c6cb13ae | 397 | goto err_out_reboot; |
1da177e4 LT |
398 | } |
399 | ||
173d95bc | 400 | if (nowayout) |
1da177e4 | 401 | __module_get(THIS_MODULE); |
1da177e4 | 402 | |
27c766aa | 403 | pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n", |
1da177e4 LT |
404 | timeout, nowayout); |
405 | return 0; | |
406 | ||
c6cb13ae WVS |
407 | err_out_reboot: |
408 | unregister_reboot_notifier(&wdt_notifier); | |
1da177e4 | 409 | err_out: |
02be2ee9 | 410 | pci_dev_put(alim7101_pmu); |
1da177e4 LT |
411 | return rc; |
412 | } | |
413 | ||
414 | module_init(alim7101_wdt_init); | |
415 | module_exit(alim7101_wdt_unload); | |
416 | ||
bc17f9dc | 417 | static const struct pci_device_id alim7101_pci_tbl[] __used = { |
29d73aab JS |
418 | { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) }, |
419 | { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) }, | |
5cacb9f8 BC |
420 | { } |
421 | }; | |
422 | ||
423 | MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl); | |
424 | ||
1da177e4 LT |
425 | MODULE_AUTHOR("Steve Hill"); |
426 | MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver"); | |
427 | MODULE_LICENSE("GPL"); |