Commit | Line | Data |
---|---|---|
09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * ALi M7101 PMU Computer Watchdog Timer driver | |
4 | * | |
5 | * Based on w83877f_wdt.c by Scott Jennings <linuxdrivers@oro.net> | |
6 | * and the Cobalt kernel WDT timer driver by Tim Hockin | |
7 | * <thockin@cobaltnet.com> | |
8 | * | |
9 | * (c)2002 Steve Hill <steve@navaho.co.uk> | |
10 | * | |
11 | * This WDT driver is different from most other Linux WDT | |
12 | * drivers in that the driver will ping the watchdog by itself, | |
13 | * because this particular WDT has a very short timeout (1.6 | |
14 | * seconds) and it would be insane to count on any userspace | |
15 | * daemon always getting scheduled within that time frame. | |
16 | * | |
17 | * Additions: | |
18 | * Aug 23, 2004 - Added use_gpio module parameter for use on revision a1d PMUs | |
19 | * found on very old cobalt hardware. | |
20 | * -- Mike Waychison <michael.waychison@sun.com> | |
21 | */ | |
22 | ||
27c766aa JP |
23 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
24 | ||
1da177e4 LT |
25 | #include <linux/module.h> |
26 | #include <linux/moduleparam.h> | |
27 | #include <linux/types.h> | |
28 | #include <linux/timer.h> | |
29 | #include <linux/miscdevice.h> | |
30 | #include <linux/watchdog.h> | |
31 | #include <linux/ioport.h> | |
32 | #include <linux/notifier.h> | |
33 | #include <linux/reboot.h> | |
34 | #include <linux/init.h> | |
35 | #include <linux/fs.h> | |
36 | #include <linux/pci.h> | |
173d95bc AC |
37 | #include <linux/io.h> |
38 | #include <linux/uaccess.h> | |
089ab079 | 39 | |
1da177e4 | 40 | |
1da177e4 LT |
41 | #define WDT_ENABLE 0x9C |
42 | #define WDT_DISABLE 0x8C | |
43 | ||
44 | #define ALI_7101_WDT 0x92 | |
45 | #define ALI_7101_GPIO 0x7D | |
46 | #define ALI_7101_GPIO_O 0x7E | |
47 | #define ALI_WDT_ARM 0x01 | |
48 | ||
49 | /* | |
50 | * We're going to use a 1 second timeout. | |
51 | * If we reset the watchdog every ~250ms we should be safe. */ | |
52 | ||
53 | #define WDT_INTERVAL (HZ/4+1) | |
54 | ||
55 | /* | |
56 | * We must not require too good response from the userspace daemon. | |
57 | * Here we require the userspace daemon to send us a heartbeat | |
58 | * char to /dev/watchdog every 30 seconds. | |
59 | */ | |
60 | ||
61 | #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ | |
173d95bc AC |
62 | /* in seconds, will be multiplied by HZ to get seconds to wait for a ping */ |
63 | static int timeout = WATCHDOG_TIMEOUT; | |
1da177e4 | 64 | module_param(timeout, int, 0); |
173d95bc AC |
65 | MODULE_PARM_DESC(timeout, |
66 | "Watchdog timeout in seconds. (1<=timeout<=3600, default=" | |
67 | __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); | |
1da177e4 | 68 | |
173d95bc | 69 | static int use_gpio; /* Use the pic (for a1d revision alim7101) */ |
1da177e4 | 70 | module_param(use_gpio, int, 0); |
173d95bc AC |
71 | MODULE_PARM_DESC(use_gpio, |
72 | "Use the gpio watchdog (required by old cobalt boards)."); | |
1da177e4 | 73 | |
24ed960a | 74 | static void wdt_timer_ping(struct timer_list *); |
1d27e3e2 | 75 | static DEFINE_TIMER(timer, wdt_timer_ping); |
1da177e4 LT |
76 | static unsigned long next_heartbeat; |
77 | static unsigned long wdt_is_open; | |
78 | static char wdt_expect_close; | |
79 | static struct pci_dev *alim7101_pmu; | |
80 | ||
86a1e189 WVS |
81 | static bool nowayout = WATCHDOG_NOWAYOUT; |
82 | module_param(nowayout, bool, 0); | |
173d95bc AC |
83 | MODULE_PARM_DESC(nowayout, |
84 | "Watchdog cannot be stopped once started (default=" | |
85 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
86 | |
87 | /* | |
88 | * Whack the dog | |
89 | */ | |
90 | ||
24ed960a | 91 | static void wdt_timer_ping(struct timer_list *unused) |
1da177e4 LT |
92 | { |
93 | /* If we got a heartbeat pulse within the WDT_US_INTERVAL | |
94 | * we agree to ping the WDT | |
95 | */ | |
173d95bc | 96 | char tmp; |
1da177e4 | 97 | |
173d95bc | 98 | if (time_before(jiffies, next_heartbeat)) { |
1da177e4 LT |
99 | /* Ping the WDT (this is actually a disarm/arm sequence) */ |
100 | pci_read_config_byte(alim7101_pmu, 0x92, &tmp); | |
173d95bc AC |
101 | pci_write_config_byte(alim7101_pmu, |
102 | ALI_7101_WDT, (tmp & ~ALI_WDT_ARM)); | |
103 | pci_write_config_byte(alim7101_pmu, | |
104 | ALI_7101_WDT, (tmp | ALI_WDT_ARM)); | |
1da177e4 | 105 | if (use_gpio) { |
173d95bc AC |
106 | pci_read_config_byte(alim7101_pmu, |
107 | ALI_7101_GPIO_O, &tmp); | |
108 | pci_write_config_byte(alim7101_pmu, | |
109 | ALI_7101_GPIO_O, tmp | 0x20); | |
110 | pci_write_config_byte(alim7101_pmu, | |
111 | ALI_7101_GPIO_O, tmp & ~0x20); | |
1da177e4 LT |
112 | } |
113 | } else { | |
27c766aa | 114 | pr_warn("Heartbeat lost! Will not ping the watchdog\n"); |
1da177e4 LT |
115 | } |
116 | /* Re-set the timer interval */ | |
82eb7c50 | 117 | mod_timer(&timer, jiffies + WDT_INTERVAL); |
1da177e4 LT |
118 | } |
119 | ||
120 | /* | |
121 | * Utility routines | |
122 | */ | |
123 | ||
124 | static void wdt_change(int writeval) | |
125 | { | |
7944d3a5 | 126 | char tmp; |
1da177e4 LT |
127 | |
128 | pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp); | |
129 | if (writeval == WDT_ENABLE) { | |
173d95bc AC |
130 | pci_write_config_byte(alim7101_pmu, |
131 | ALI_7101_WDT, (tmp | ALI_WDT_ARM)); | |
1da177e4 | 132 | if (use_gpio) { |
173d95bc AC |
133 | pci_read_config_byte(alim7101_pmu, |
134 | ALI_7101_GPIO_O, &tmp); | |
135 | pci_write_config_byte(alim7101_pmu, | |
136 | ALI_7101_GPIO_O, tmp & ~0x20); | |
1da177e4 LT |
137 | } |
138 | ||
139 | } else { | |
173d95bc AC |
140 | pci_write_config_byte(alim7101_pmu, |
141 | ALI_7101_WDT, (tmp & ~ALI_WDT_ARM)); | |
1da177e4 | 142 | if (use_gpio) { |
173d95bc AC |
143 | pci_read_config_byte(alim7101_pmu, |
144 | ALI_7101_GPIO_O, &tmp); | |
145 | pci_write_config_byte(alim7101_pmu, | |
146 | ALI_7101_GPIO_O, tmp | 0x20); | |
1da177e4 LT |
147 | } |
148 | } | |
149 | } | |
150 | ||
151 | static void wdt_startup(void) | |
152 | { | |
153 | next_heartbeat = jiffies + (timeout * HZ); | |
154 | ||
155 | /* We must enable before we kick off the timer in case the timer | |
156 | occurs as we ping it */ | |
157 | ||
158 | wdt_change(WDT_ENABLE); | |
159 | ||
160 | /* Start the timer */ | |
82eb7c50 | 161 | mod_timer(&timer, jiffies + WDT_INTERVAL); |
1da177e4 | 162 | |
27c766aa | 163 | pr_info("Watchdog timer is now enabled\n"); |
1da177e4 LT |
164 | } |
165 | ||
166 | static void wdt_turnoff(void) | |
167 | { | |
168 | /* Stop the timer */ | |
169 | del_timer_sync(&timer); | |
170 | wdt_change(WDT_DISABLE); | |
27c766aa | 171 | pr_info("Watchdog timer is now disabled...\n"); |
1da177e4 LT |
172 | } |
173 | ||
174 | static void wdt_keepalive(void) | |
175 | { | |
176 | /* user land ping */ | |
177 | next_heartbeat = jiffies + (timeout * HZ); | |
178 | } | |
179 | ||
180 | /* | |
181 | * /dev/watchdog handling | |
182 | */ | |
183 | ||
173d95bc AC |
184 | static ssize_t fop_write(struct file *file, const char __user *buf, |
185 | size_t count, loff_t *ppos) | |
1da177e4 LT |
186 | { |
187 | /* See if we got the magic character 'V' and reload the timer */ | |
173d95bc | 188 | if (count) { |
1da177e4 LT |
189 | if (!nowayout) { |
190 | size_t ofs; | |
191 | ||
192 | /* note: just in case someone wrote the magic character | |
193 | * five months ago... */ | |
194 | wdt_expect_close = 0; | |
195 | ||
196 | /* now scan */ | |
197 | for (ofs = 0; ofs != count; ofs++) { | |
198 | char c; | |
7944d3a5 | 199 | if (get_user(c, buf + ofs)) |
1da177e4 LT |
200 | return -EFAULT; |
201 | if (c == 'V') | |
202 | wdt_expect_close = 42; | |
203 | } | |
204 | } | |
205 | /* someone wrote to us, we should restart timer */ | |
206 | wdt_keepalive(); | |
207 | } | |
208 | return count; | |
209 | } | |
210 | ||
173d95bc | 211 | static int fop_open(struct inode *inode, struct file *file) |
1da177e4 LT |
212 | { |
213 | /* Just in case we're already talking to someone... */ | |
173d95bc | 214 | if (test_and_set_bit(0, &wdt_is_open)) |
1da177e4 LT |
215 | return -EBUSY; |
216 | /* Good, fire up the show */ | |
217 | wdt_startup(); | |
c5bf68fe | 218 | return stream_open(inode, file); |
1da177e4 LT |
219 | } |
220 | ||
173d95bc | 221 | static int fop_close(struct inode *inode, struct file *file) |
1da177e4 | 222 | { |
173d95bc | 223 | if (wdt_expect_close == 42) |
1da177e4 LT |
224 | wdt_turnoff(); |
225 | else { | |
226 | /* wim: shouldn't there be a: del_timer(&timer); */ | |
27c766aa | 227 | pr_crit("device file closed unexpectedly. Will not stop the WDT!\n"); |
1da177e4 LT |
228 | } |
229 | clear_bit(0, &wdt_is_open); | |
230 | wdt_expect_close = 0; | |
231 | return 0; | |
232 | } | |
233 | ||
173d95bc | 234 | static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
235 | { |
236 | void __user *argp = (void __user *)arg; | |
237 | int __user *p = argp; | |
42747d71 | 238 | static const struct watchdog_info ident = { |
173d95bc AC |
239 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
240 | | WDIOF_MAGICCLOSE, | |
1da177e4 LT |
241 | .firmware_version = 1, |
242 | .identity = "ALiM7101", | |
243 | }; | |
244 | ||
173d95bc AC |
245 | switch (cmd) { |
246 | case WDIOC_GETSUPPORT: | |
247 | return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; | |
248 | case WDIOC_GETSTATUS: | |
249 | case WDIOC_GETBOOTSTATUS: | |
250 | return put_user(0, p); | |
173d95bc | 251 | case WDIOC_SETOPTIONS: |
1da177e4 | 252 | { |
173d95bc | 253 | int new_options, retval = -EINVAL; |
1da177e4 | 254 | |
173d95bc AC |
255 | if (get_user(new_options, p)) |
256 | return -EFAULT; | |
257 | if (new_options & WDIOS_DISABLECARD) { | |
258 | wdt_turnoff(); | |
259 | retval = 0; | |
1da177e4 | 260 | } |
173d95bc AC |
261 | if (new_options & WDIOS_ENABLECARD) { |
262 | wdt_startup(); | |
263 | retval = 0; | |
1da177e4 | 264 | } |
173d95bc AC |
265 | return retval; |
266 | } | |
0c06090c WVS |
267 | case WDIOC_KEEPALIVE: |
268 | wdt_keepalive(); | |
269 | return 0; | |
173d95bc AC |
270 | case WDIOC_SETTIMEOUT: |
271 | { | |
272 | int new_timeout; | |
273 | ||
274 | if (get_user(new_timeout, p)) | |
275 | return -EFAULT; | |
276 | /* arbitrary upper limit */ | |
277 | if (new_timeout < 1 || new_timeout > 3600) | |
278 | return -EINVAL; | |
279 | timeout = new_timeout; | |
280 | wdt_keepalive(); | |
173d95bc | 281 | } |
bd490f82 | 282 | fallthrough; |
173d95bc AC |
283 | case WDIOC_GETTIMEOUT: |
284 | return put_user(timeout, p); | |
285 | default: | |
286 | return -ENOTTY; | |
1da177e4 LT |
287 | } |
288 | } | |
289 | ||
62322d25 | 290 | static const struct file_operations wdt_fops = { |
173d95bc AC |
291 | .owner = THIS_MODULE, |
292 | .llseek = no_llseek, | |
293 | .write = fop_write, | |
294 | .open = fop_open, | |
295 | .release = fop_close, | |
296 | .unlocked_ioctl = fop_ioctl, | |
b6dfb247 | 297 | .compat_ioctl = compat_ptr_ioctl, |
1da177e4 LT |
298 | }; |
299 | ||
300 | static struct miscdevice wdt_miscdev = { | |
173d95bc AC |
301 | .minor = WATCHDOG_MINOR, |
302 | .name = "watchdog", | |
303 | .fops = &wdt_fops, | |
1da177e4 LT |
304 | }; |
305 | ||
87ffc69e GR |
306 | static int wdt_restart_handle(struct notifier_block *this, unsigned long mode, |
307 | void *cmd) | |
308 | { | |
309 | /* | |
310 | * Cobalt devices have no way of rebooting themselves other | |
311 | * than getting the watchdog to pull reset, so we restart the | |
312 | * watchdog on reboot with no heartbeat. | |
313 | */ | |
314 | wdt_change(WDT_ENABLE); | |
315 | ||
316 | /* loop until the watchdog fires */ | |
317 | while (true) | |
318 | ; | |
319 | ||
320 | return NOTIFY_DONE; | |
321 | } | |
322 | ||
323 | static struct notifier_block wdt_restart_handler = { | |
324 | .notifier_call = wdt_restart_handle, | |
325 | .priority = 128, | |
326 | }; | |
327 | ||
1da177e4 LT |
328 | /* |
329 | * Notifier for system down | |
330 | */ | |
331 | ||
173d95bc AC |
332 | static int wdt_notify_sys(struct notifier_block *this, |
333 | unsigned long code, void *unused) | |
1da177e4 | 334 | { |
173d95bc | 335 | if (code == SYS_DOWN || code == SYS_HALT) |
1da177e4 LT |
336 | wdt_turnoff(); |
337 | ||
1da177e4 LT |
338 | return NOTIFY_DONE; |
339 | } | |
340 | ||
341 | /* | |
342 | * The WDT needs to learn about soft shutdowns in order to | |
343 | * turn the timebomb registers off. | |
344 | */ | |
345 | ||
173d95bc | 346 | static struct notifier_block wdt_notifier = { |
1da177e4 LT |
347 | .notifier_call = wdt_notify_sys, |
348 | }; | |
349 | ||
350 | static void __exit alim7101_wdt_unload(void) | |
351 | { | |
352 | wdt_turnoff(); | |
353 | /* Deregister */ | |
354 | misc_deregister(&wdt_miscdev); | |
355 | unregister_reboot_notifier(&wdt_notifier); | |
87ffc69e | 356 | unregister_restart_handler(&wdt_restart_handler); |
02be2ee9 | 357 | pci_dev_put(alim7101_pmu); |
1da177e4 LT |
358 | } |
359 | ||
360 | static int __init alim7101_wdt_init(void) | |
361 | { | |
362 | int rc = -EBUSY; | |
363 | struct pci_dev *ali1543_south; | |
364 | char tmp; | |
365 | ||
27c766aa | 366 | pr_info("Steve Hill <steve@navaho.co.uk>\n"); |
02be2ee9 JS |
367 | alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101, |
368 | NULL); | |
1da177e4 | 369 | if (!alim7101_pmu) { |
27c766aa | 370 | pr_info("ALi M7101 PMU not present - WDT not set\n"); |
1da177e4 LT |
371 | return -EBUSY; |
372 | } | |
373 | ||
374 | /* Set the WDT in the PMU to 1 second */ | |
375 | pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02); | |
376 | ||
02be2ee9 JS |
377 | ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, |
378 | NULL); | |
1da177e4 | 379 | if (!ali1543_south) { |
27c766aa | 380 | pr_info("ALi 1543 South-Bridge not present - WDT not set\n"); |
02be2ee9 | 381 | goto err_out; |
1da177e4 LT |
382 | } |
383 | pci_read_config_byte(ali1543_south, 0x5e, &tmp); | |
02be2ee9 | 384 | pci_dev_put(ali1543_south); |
1da177e4 LT |
385 | if ((tmp & 0x1e) == 0x00) { |
386 | if (!use_gpio) { | |
27c766aa | 387 | pr_info("Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n"); |
02be2ee9 | 388 | goto err_out; |
173d95bc | 389 | } |
1da177e4 LT |
390 | nowayout = 1; |
391 | } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) { | |
27c766aa | 392 | pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n"); |
02be2ee9 | 393 | goto err_out; |
1da177e4 LT |
394 | } |
395 | ||
173d95bc AC |
396 | if (timeout < 1 || timeout > 3600) { |
397 | /* arbitrary upper limit */ | |
1da177e4 | 398 | timeout = WATCHDOG_TIMEOUT; |
27c766aa JP |
399 | pr_info("timeout value must be 1 <= x <= 3600, using %d\n", |
400 | timeout); | |
1da177e4 LT |
401 | } |
402 | ||
c6cb13ae | 403 | rc = register_reboot_notifier(&wdt_notifier); |
1da177e4 | 404 | if (rc) { |
27c766aa | 405 | pr_err("cannot register reboot notifier (err=%d)\n", rc); |
1da177e4 LT |
406 | goto err_out; |
407 | } | |
408 | ||
87ffc69e GR |
409 | rc = register_restart_handler(&wdt_restart_handler); |
410 | if (rc) { | |
411 | pr_err("cannot register restart handler (err=%d)\n", rc); | |
412 | goto err_out_reboot; | |
413 | } | |
414 | ||
c6cb13ae | 415 | rc = misc_register(&wdt_miscdev); |
1da177e4 | 416 | if (rc) { |
27c766aa JP |
417 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
418 | wdt_miscdev.minor, rc); | |
87ffc69e | 419 | goto err_out_restart; |
1da177e4 LT |
420 | } |
421 | ||
173d95bc | 422 | if (nowayout) |
1da177e4 | 423 | __module_get(THIS_MODULE); |
1da177e4 | 424 | |
27c766aa | 425 | pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n", |
1da177e4 LT |
426 | timeout, nowayout); |
427 | return 0; | |
428 | ||
87ffc69e GR |
429 | err_out_restart: |
430 | unregister_restart_handler(&wdt_restart_handler); | |
c6cb13ae WVS |
431 | err_out_reboot: |
432 | unregister_reboot_notifier(&wdt_notifier); | |
1da177e4 | 433 | err_out: |
02be2ee9 | 434 | pci_dev_put(alim7101_pmu); |
1da177e4 LT |
435 | return rc; |
436 | } | |
437 | ||
438 | module_init(alim7101_wdt_init); | |
439 | module_exit(alim7101_wdt_unload); | |
440 | ||
bc17f9dc | 441 | static const struct pci_device_id alim7101_pci_tbl[] __used = { |
29d73aab JS |
442 | { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) }, |
443 | { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) }, | |
5cacb9f8 BC |
444 | { } |
445 | }; | |
446 | ||
447 | MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl); | |
448 | ||
1da177e4 LT |
449 | MODULE_AUTHOR("Steve Hill"); |
450 | MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver"); | |
451 | MODULE_LICENSE("GPL"); |