blob: 0a77655cda60d6341f379d674b48bce17e6166c3 [file] [log] [blame]
Utz Bacher031f7ed2005-06-23 09:43:34 +10001/*
2 * FIXME: add wdrtas_get_status and wdrtas_get_boot_status as soon as
3 * RTAS calls are available
4 */
5
6/*
7 * RTAS watchdog driver
8 *
9 * (C) Copyright IBM Corp. 2005
10 * device driver to exploit watchdog RTAS functions
11 *
12 * Authors : Utz Bacher <utz.bacher@de.ibm.com>
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2, or (at your option)
17 * any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 */
28
Joe Perches27c766a2012-02-15 15:06:19 -080029#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30
Utz Bacher031f7ed2005-06-23 09:43:34 +100031#include <linux/fs.h>
32#include <linux/init.h>
33#include <linux/kernel.h>
34#include <linux/miscdevice.h>
35#include <linux/module.h>
36#include <linux/notifier.h>
37#include <linux/reboot.h>
38#include <linux/types.h>
39#include <linux/watchdog.h>
Alan Coxdae67a22008-05-19 14:09:45 +010040#include <linux/uaccess.h>
Utz Bacher031f7ed2005-06-23 09:43:34 +100041
42#include <asm/rtas.h>
Utz Bacher031f7ed2005-06-23 09:43:34 +100043
44#define WDRTAS_MAGIC_CHAR 42
45#define WDRTAS_SUPPORTED_MASK (WDIOF_SETTIMEOUT | \
46 WDIOF_MAGICCLOSE)
47
48MODULE_AUTHOR("Utz Bacher <utz.bacher@de.ibm.com>");
49MODULE_DESCRIPTION("RTAS watchdog driver");
50MODULE_LICENSE("GPL");
51MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
52MODULE_ALIAS_MISCDEV(TEMP_MINOR);
53
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010054static bool wdrtas_nowayout = WATCHDOG_NOWAYOUT;
Utz Bacher031f7ed2005-06-23 09:43:34 +100055static atomic_t wdrtas_miscdev_open = ATOMIC_INIT(0);
Alan Coxdae67a22008-05-19 14:09:45 +010056static char wdrtas_expect_close;
Utz Bacher031f7ed2005-06-23 09:43:34 +100057
58static int wdrtas_interval;
59
60#define WDRTAS_THERMAL_SENSOR 3
61static int wdrtas_token_get_sensor_state;
62#define WDRTAS_SURVEILLANCE_IND 9000
63static int wdrtas_token_set_indicator;
64#define WDRTAS_SP_SPI 28
65static int wdrtas_token_get_sp;
66static int wdrtas_token_event_scan;
67
68#define WDRTAS_DEFAULT_INTERVAL 300
69
70#define WDRTAS_LOGBUFFER_LEN 128
71static char wdrtas_logbuffer[WDRTAS_LOGBUFFER_LEN];
72
73
74/*** watchdog access functions */
75
76/**
77 * wdrtas_set_interval - sets the watchdog interval
78 * @interval: new interval
79 *
80 * returns 0 on success, <0 on failures
81 *
82 * wdrtas_set_interval sets the watchdog keepalive interval by calling the
83 * RTAS function set-indicator (surveillance). The unit of interval is
84 * seconds.
85 */
Alan Coxdae67a22008-05-19 14:09:45 +010086
87static int wdrtas_set_interval(int interval)
Utz Bacher031f7ed2005-06-23 09:43:34 +100088{
89 long result;
90 static int print_msg = 10;
91
92 /* rtas uses minutes */
93 interval = (interval + 59) / 60;
94
95 result = rtas_call(wdrtas_token_set_indicator, 3, 1, NULL,
96 WDRTAS_SURVEILLANCE_IND, 0, interval);
Alan Coxdae67a22008-05-19 14:09:45 +010097 if (result < 0 && print_msg) {
Joe Perches27c766a2012-02-15 15:06:19 -080098 pr_err("setting the watchdog to %i timeout failed: %li\n",
99 interval, result);
Utz Bacher031f7ed2005-06-23 09:43:34 +1000100 print_msg--;
101 }
102
103 return result;
104}
105
Mark Nelsonb6966b12009-03-23 20:30:41 +0000106#define WDRTAS_SP_SPI_LEN 4
107
Utz Bacher031f7ed2005-06-23 09:43:34 +1000108/**
109 * wdrtas_get_interval - returns the current watchdog interval
110 * @fallback_value: value (in seconds) to use, if the RTAS call fails
111 *
112 * returns the interval
113 *
114 * wdrtas_get_interval returns the current watchdog keepalive interval
115 * as reported by the RTAS function ibm,get-system-parameter. The unit
116 * of the return value is seconds.
117 */
Alan Coxdae67a22008-05-19 14:09:45 +0100118static int wdrtas_get_interval(int fallback_value)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000119{
120 long result;
Mark Nelsonb6966b12009-03-23 20:30:41 +0000121 char value[WDRTAS_SP_SPI_LEN];
Utz Bacher031f7ed2005-06-23 09:43:34 +1000122
Mark Nelsonb6966b12009-03-23 20:30:41 +0000123 spin_lock(&rtas_data_buf_lock);
124 memset(rtas_data_buf, 0, WDRTAS_SP_SPI_LEN);
Utz Bacher031f7ed2005-06-23 09:43:34 +1000125 result = rtas_call(wdrtas_token_get_sp, 3, 1, NULL,
Mark Nelsonb6966b12009-03-23 20:30:41 +0000126 WDRTAS_SP_SPI, __pa(rtas_data_buf),
127 WDRTAS_SP_SPI_LEN);
128
129 memcpy(value, rtas_data_buf, WDRTAS_SP_SPI_LEN);
130 spin_unlock(&rtas_data_buf_lock);
131
Alan Coxdae67a22008-05-19 14:09:45 +0100132 if (value[0] != 0 || value[1] != 2 || value[3] != 0 || result < 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800133 pr_warn("could not get sp_spi watchdog timeout (%li). Continuing\n",
134 result);
Utz Bacher031f7ed2005-06-23 09:43:34 +1000135 return fallback_value;
136 }
137
138 /* rtas uses minutes */
139 return ((int)value[2]) * 60;
140}
141
142/**
143 * wdrtas_timer_start - starts watchdog
144 *
145 * wdrtas_timer_start starts the watchdog by calling the RTAS function
146 * set-interval (surveillance)
147 */
Alan Coxdae67a22008-05-19 14:09:45 +0100148static void wdrtas_timer_start(void)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000149{
150 wdrtas_set_interval(wdrtas_interval);
151}
152
153/**
154 * wdrtas_timer_stop - stops watchdog
155 *
156 * wdrtas_timer_stop stops the watchdog timer by calling the RTAS function
157 * set-interval (surveillance)
158 */
Alan Coxdae67a22008-05-19 14:09:45 +0100159static void wdrtas_timer_stop(void)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000160{
161 wdrtas_set_interval(0);
162}
163
164/**
165 * wdrtas_log_scanned_event - logs an event we received during keepalive
166 *
167 * wdrtas_log_scanned_event prints a message to the log buffer dumping
168 * the results of the last event-scan call
169 */
Alan Coxdae67a22008-05-19 14:09:45 +0100170static void wdrtas_log_scanned_event(void)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000171{
172 int i;
173
174 for (i = 0; i < WDRTAS_LOGBUFFER_LEN; i += 16)
Joe Perches27c766a2012-02-15 15:06:19 -0800175 pr_info("dumping event (line %i/%i), data = "
176 "%02x %02x %02x %02x %02x %02x %02x %02x "
177 "%02x %02x %02x %02x %02x %02x %02x %02x\n",
178 (i / 16) + 1, (WDRTAS_LOGBUFFER_LEN / 16),
179 wdrtas_logbuffer[i + 0], wdrtas_logbuffer[i + 1],
180 wdrtas_logbuffer[i + 2], wdrtas_logbuffer[i + 3],
181 wdrtas_logbuffer[i + 4], wdrtas_logbuffer[i + 5],
182 wdrtas_logbuffer[i + 6], wdrtas_logbuffer[i + 7],
183 wdrtas_logbuffer[i + 8], wdrtas_logbuffer[i + 9],
184 wdrtas_logbuffer[i + 10], wdrtas_logbuffer[i + 11],
185 wdrtas_logbuffer[i + 12], wdrtas_logbuffer[i + 13],
186 wdrtas_logbuffer[i + 14], wdrtas_logbuffer[i + 15]);
Utz Bacher031f7ed2005-06-23 09:43:34 +1000187}
188
189/**
190 * wdrtas_timer_keepalive - resets watchdog timer to keep system alive
191 *
192 * wdrtas_timer_keepalive restarts the watchdog timer by calling the
193 * RTAS function event-scan and repeats these calls as long as there are
194 * events available. All events will be dumped.
195 */
Alan Coxdae67a22008-05-19 14:09:45 +0100196static void wdrtas_timer_keepalive(void)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000197{
198 long result;
199
200 do {
201 result = rtas_call(wdrtas_token_event_scan, 4, 1, NULL,
202 RTAS_EVENT_SCAN_ALL_EVENTS, 0,
203 (void *)__pa(wdrtas_logbuffer),
204 WDRTAS_LOGBUFFER_LEN);
205 if (result < 0)
Joe Perches27c766a2012-02-15 15:06:19 -0800206 pr_err("event-scan failed: %li\n", result);
Utz Bacher031f7ed2005-06-23 09:43:34 +1000207 if (result == 0)
208 wdrtas_log_scanned_event();
209 } while (result == 0);
210}
211
212/**
213 * wdrtas_get_temperature - returns current temperature
214 *
215 * returns temperature or <0 on failures
216 *
217 * wdrtas_get_temperature returns the current temperature in Fahrenheit. It
218 * uses the RTAS call get-sensor-state, token 3 to do so
219 */
Alan Coxdae67a22008-05-19 14:09:45 +0100220static int wdrtas_get_temperature(void)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000221{
Adrian Reber5ba762c2009-03-26 02:05:42 +0000222 int result;
Utz Bacher031f7ed2005-06-23 09:43:34 +1000223 int temperature = 0;
224
Adrian Reber5ba762c2009-03-26 02:05:42 +0000225 result = rtas_get_sensor(WDRTAS_THERMAL_SENSOR, 0, &temperature);
Utz Bacher031f7ed2005-06-23 09:43:34 +1000226
227 if (result < 0)
Joe Perches27c766a2012-02-15 15:06:19 -0800228 pr_warn("reading the thermal sensor failed: %i\n", result);
Utz Bacher031f7ed2005-06-23 09:43:34 +1000229 else
230 temperature = ((temperature * 9) / 5) + 32; /* fahrenheit */
231
232 return temperature;
233}
234
235/**
236 * wdrtas_get_status - returns the status of the watchdog
237 *
238 * returns a bitmask of defines WDIOF_... as defined in
239 * include/linux/watchdog.h
240 */
Alan Coxdae67a22008-05-19 14:09:45 +0100241static int wdrtas_get_status(void)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000242{
243 return 0; /* TODO */
244}
245
246/**
247 * wdrtas_get_boot_status - returns the reason for the last boot
248 *
249 * returns a bitmask of defines WDIOF_... as defined in
250 * include/linux/watchdog.h, indicating why the watchdog rebooted the system
251 */
Alan Coxdae67a22008-05-19 14:09:45 +0100252static int wdrtas_get_boot_status(void)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000253{
254 return 0; /* TODO */
255}
256
257/*** watchdog API and operations stuff */
258
259/* wdrtas_write - called when watchdog device is written to
260 * @file: file structure
261 * @buf: user buffer with data
262 * @len: amount to data written
263 * @ppos: position in file
264 *
265 * returns the number of successfully processed characters, which is always
266 * the number of bytes passed to this function
267 *
268 * wdrtas_write processes all the data given to it and looks for the magic
269 * character 'V'. This character allows the watchdog device to be closed
270 * properly.
271 */
Alan Coxdae67a22008-05-19 14:09:45 +0100272static ssize_t wdrtas_write(struct file *file, const char __user *buf,
Utz Bacher031f7ed2005-06-23 09:43:34 +1000273 size_t len, loff_t *ppos)
274{
275 int i;
276 char c;
277
278 if (!len)
279 goto out;
280
281 if (!wdrtas_nowayout) {
282 wdrtas_expect_close = 0;
283 /* look for 'V' */
284 for (i = 0; i < len; i++) {
285 if (get_user(c, buf + i))
286 return -EFAULT;
287 /* allow to close device */
288 if (c == 'V')
289 wdrtas_expect_close = WDRTAS_MAGIC_CHAR;
290 }
291 }
292
293 wdrtas_timer_keepalive();
294
295out:
296 return len;
297}
298
299/**
300 * wdrtas_ioctl - ioctl function for the watchdog device
Utz Bacher031f7ed2005-06-23 09:43:34 +1000301 * @file: file structure
302 * @cmd: command for ioctl
303 * @arg: argument pointer
304 *
305 * returns 0 on success, <0 on failure
306 *
307 * wdrtas_ioctl implements the watchdog API ioctls
308 */
Alan Coxdae67a22008-05-19 14:09:45 +0100309
310static long wdrtas_ioctl(struct file *file, unsigned int cmd,
311 unsigned long arg)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000312{
Al Viroe896fd92005-12-15 09:18:05 +0000313 int __user *argp = (void __user *)arg;
Utz Bacher031f7ed2005-06-23 09:43:34 +1000314 int i;
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000315 static const struct watchdog_info wdinfo = {
Utz Bacher031f7ed2005-06-23 09:43:34 +1000316 .options = WDRTAS_SUPPORTED_MASK,
317 .firmware_version = 0,
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000318 .identity = "wdrtas",
Utz Bacher031f7ed2005-06-23 09:43:34 +1000319 };
320
321 switch (cmd) {
322 case WDIOC_GETSUPPORT:
323 if (copy_to_user(argp, &wdinfo, sizeof(wdinfo)))
324 return -EFAULT;
325 return 0;
326
327 case WDIOC_GETSTATUS:
328 i = wdrtas_get_status();
329 return put_user(i, argp);
330
331 case WDIOC_GETBOOTSTATUS:
332 i = wdrtas_get_boot_status();
333 return put_user(i, argp);
334
335 case WDIOC_GETTEMP:
336 if (wdrtas_token_get_sensor_state == RTAS_UNKNOWN_SERVICE)
337 return -EOPNOTSUPP;
338
339 i = wdrtas_get_temperature();
340 return put_user(i, argp);
341
342 case WDIOC_SETOPTIONS:
343 if (get_user(i, argp))
344 return -EFAULT;
345 if (i & WDIOS_DISABLECARD)
346 wdrtas_timer_stop();
347 if (i & WDIOS_ENABLECARD) {
348 wdrtas_timer_keepalive();
349 wdrtas_timer_start();
350 }
Alan Coxdae67a22008-05-19 14:09:45 +0100351 /* not implemented. Done by H8
Utz Bacher031f7ed2005-06-23 09:43:34 +1000352 if (i & WDIOS_TEMPPANIC) {
Alan Coxdae67a22008-05-19 14:09:45 +0100353 } */
Utz Bacher031f7ed2005-06-23 09:43:34 +1000354 return 0;
355
356 case WDIOC_KEEPALIVE:
357 wdrtas_timer_keepalive();
358 return 0;
359
360 case WDIOC_SETTIMEOUT:
361 if (get_user(i, argp))
362 return -EFAULT;
363
364 if (wdrtas_set_interval(i))
365 return -EINVAL;
366
367 wdrtas_timer_keepalive();
368
369 if (wdrtas_token_get_sp == RTAS_UNKNOWN_SERVICE)
370 wdrtas_interval = i;
371 else
372 wdrtas_interval = wdrtas_get_interval(i);
373 /* fallthrough */
374
375 case WDIOC_GETTIMEOUT:
376 return put_user(wdrtas_interval, argp);
377
378 default:
Samuel Tardieu795b89d2006-09-09 17:34:31 +0200379 return -ENOTTY;
Utz Bacher031f7ed2005-06-23 09:43:34 +1000380 }
381}
382
383/**
384 * wdrtas_open - open function of watchdog device
385 * @inode: inode structure
386 * @file: file structure
387 *
388 * returns 0 on success, -EBUSY if the file has been opened already, <0 on
389 * other failures
390 *
391 * function called when watchdog device is opened
392 */
Alan Coxdae67a22008-05-19 14:09:45 +0100393static int wdrtas_open(struct inode *inode, struct file *file)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000394{
395 /* only open once */
396 if (atomic_inc_return(&wdrtas_miscdev_open) > 1) {
397 atomic_dec(&wdrtas_miscdev_open);
398 return -EBUSY;
399 }
400
401 wdrtas_timer_start();
402 wdrtas_timer_keepalive();
403
404 return nonseekable_open(inode, file);
405}
406
407/**
408 * wdrtas_close - close function of watchdog device
409 * @inode: inode structure
410 * @file: file structure
411 *
412 * returns 0 on success
413 *
414 * close function. Always succeeds
415 */
Alan Coxdae67a22008-05-19 14:09:45 +0100416static int wdrtas_close(struct inode *inode, struct file *file)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000417{
418 /* only stop watchdog, if this was announced using 'V' before */
419 if (wdrtas_expect_close == WDRTAS_MAGIC_CHAR)
420 wdrtas_timer_stop();
421 else {
Joe Perches27c766a2012-02-15 15:06:19 -0800422 pr_warn("got unexpected close. Watchdog not stopped.\n");
Utz Bacher031f7ed2005-06-23 09:43:34 +1000423 wdrtas_timer_keepalive();
424 }
425
426 wdrtas_expect_close = 0;
427 atomic_dec(&wdrtas_miscdev_open);
428 return 0;
429}
430
431/**
432 * wdrtas_temp_read - gives back the temperature in fahrenheit
433 * @file: file structure
434 * @buf: user buffer
435 * @count: number of bytes to be read
436 * @ppos: position in file
437 *
438 * returns always 1 or -EFAULT in case of user space copy failures, <0 on
439 * other failures
440 *
441 * wdrtas_temp_read gives the temperature to the users by copying this
442 * value as one byte into the user space buffer. The unit is Fahrenheit...
443 */
Alan Coxdae67a22008-05-19 14:09:45 +0100444static ssize_t wdrtas_temp_read(struct file *file, char __user *buf,
Utz Bacher031f7ed2005-06-23 09:43:34 +1000445 size_t count, loff_t *ppos)
446{
447 int temperature = 0;
448
449 temperature = wdrtas_get_temperature();
450 if (temperature < 0)
451 return temperature;
452
453 if (copy_to_user(buf, &temperature, 1))
454 return -EFAULT;
455
456 return 1;
457}
458
459/**
460 * wdrtas_temp_open - open function of temperature device
461 * @inode: inode structure
462 * @file: file structure
463 *
464 * returns 0 on success, <0 on failure
465 *
466 * function called when temperature device is opened
467 */
Alan Coxdae67a22008-05-19 14:09:45 +0100468static int wdrtas_temp_open(struct inode *inode, struct file *file)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000469{
470 return nonseekable_open(inode, file);
471}
472
473/**
474 * wdrtas_temp_close - close function of temperature device
475 * @inode: inode structure
476 * @file: file structure
477 *
478 * returns 0 on success
479 *
480 * close function. Always succeeds
481 */
Alan Coxdae67a22008-05-19 14:09:45 +0100482static int wdrtas_temp_close(struct inode *inode, struct file *file)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000483{
484 return 0;
485}
486
487/**
488 * wdrtas_reboot - reboot notifier function
489 * @nb: notifier block structure
490 * @code: reboot code
491 * @ptr: unused
492 *
493 * returns NOTIFY_DONE
494 *
495 * wdrtas_reboot stops the watchdog in case of a reboot
496 */
Alan Coxdae67a22008-05-19 14:09:45 +0100497static int wdrtas_reboot(struct notifier_block *this,
498 unsigned long code, void *ptr)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000499{
Alan Coxdae67a22008-05-19 14:09:45 +0100500 if (code == SYS_DOWN || code == SYS_HALT)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000501 wdrtas_timer_stop();
502
503 return NOTIFY_DONE;
504}
505
506/*** initialization stuff */
507
Arjan van de Ven62322d22006-07-03 00:24:21 -0700508static const struct file_operations wdrtas_fops = {
Utz Bacher031f7ed2005-06-23 09:43:34 +1000509 .owner = THIS_MODULE,
510 .llseek = no_llseek,
511 .write = wdrtas_write,
Alan Coxdae67a22008-05-19 14:09:45 +0100512 .unlocked_ioctl = wdrtas_ioctl,
Utz Bacher031f7ed2005-06-23 09:43:34 +1000513 .open = wdrtas_open,
514 .release = wdrtas_close,
515};
516
517static struct miscdevice wdrtas_miscdev = {
518 .minor = WATCHDOG_MINOR,
519 .name = "watchdog",
520 .fops = &wdrtas_fops,
521};
522
Arjan van de Ven62322d22006-07-03 00:24:21 -0700523static const struct file_operations wdrtas_temp_fops = {
Utz Bacher031f7ed2005-06-23 09:43:34 +1000524 .owner = THIS_MODULE,
525 .llseek = no_llseek,
526 .read = wdrtas_temp_read,
527 .open = wdrtas_temp_open,
528 .release = wdrtas_temp_close,
529};
530
531static struct miscdevice wdrtas_tempdev = {
532 .minor = TEMP_MINOR,
533 .name = "temperature",
534 .fops = &wdrtas_temp_fops,
535};
536
537static struct notifier_block wdrtas_notifier = {
538 .notifier_call = wdrtas_reboot,
539};
540
541/**
542 * wdrtas_get_tokens - reads in RTAS tokens
543 *
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200544 * returns 0 on success, <0 on failure
Utz Bacher031f7ed2005-06-23 09:43:34 +1000545 *
546 * wdrtas_get_tokens reads in the tokens for the RTAS calls used in
547 * this watchdog driver. It tolerates, if "get-sensor-state" and
548 * "ibm,get-system-parameter" are not available.
549 */
Alan Coxdae67a22008-05-19 14:09:45 +0100550static int wdrtas_get_tokens(void)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000551{
552 wdrtas_token_get_sensor_state = rtas_token("get-sensor-state");
553 if (wdrtas_token_get_sensor_state == RTAS_UNKNOWN_SERVICE) {
Joe Perches27c766a2012-02-15 15:06:19 -0800554 pr_warn("couldn't get token for get-sensor-state. Trying to continue without temperature support.\n");
Utz Bacher031f7ed2005-06-23 09:43:34 +1000555 }
556
557 wdrtas_token_get_sp = rtas_token("ibm,get-system-parameter");
558 if (wdrtas_token_get_sp == RTAS_UNKNOWN_SERVICE) {
Joe Perches27c766a2012-02-15 15:06:19 -0800559 pr_warn("couldn't get token for ibm,get-system-parameter. Trying to continue with a default timeout value of %i seconds.\n",
560 WDRTAS_DEFAULT_INTERVAL);
Utz Bacher031f7ed2005-06-23 09:43:34 +1000561 }
562
563 wdrtas_token_set_indicator = rtas_token("set-indicator");
564 if (wdrtas_token_set_indicator == RTAS_UNKNOWN_SERVICE) {
Joe Perches27c766a2012-02-15 15:06:19 -0800565 pr_err("couldn't get token for set-indicator. Terminating watchdog code.\n");
Utz Bacher031f7ed2005-06-23 09:43:34 +1000566 return -EIO;
567 }
568
569 wdrtas_token_event_scan = rtas_token("event-scan");
570 if (wdrtas_token_event_scan == RTAS_UNKNOWN_SERVICE) {
Joe Perches27c766a2012-02-15 15:06:19 -0800571 pr_err("couldn't get token for event-scan. Terminating watchdog code.\n");
Utz Bacher031f7ed2005-06-23 09:43:34 +1000572 return -EIO;
573 }
574
575 return 0;
576}
577
578/**
579 * wdrtas_unregister_devs - unregisters the misc dev handlers
580 *
581 * wdrtas_register_devs unregisters the watchdog and temperature watchdog
582 * misc devs
583 */
Alan Coxdae67a22008-05-19 14:09:45 +0100584static void wdrtas_unregister_devs(void)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000585{
586 misc_deregister(&wdrtas_miscdev);
587 if (wdrtas_token_get_sensor_state != RTAS_UNKNOWN_SERVICE)
588 misc_deregister(&wdrtas_tempdev);
589}
590
591/**
592 * wdrtas_register_devs - registers the misc dev handlers
593 *
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200594 * returns 0 on success, <0 on failure
Utz Bacher031f7ed2005-06-23 09:43:34 +1000595 *
596 * wdrtas_register_devs registers the watchdog and temperature watchdog
597 * misc devs
598 */
Alan Coxdae67a22008-05-19 14:09:45 +0100599static int wdrtas_register_devs(void)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000600{
601 int result;
602
603 result = misc_register(&wdrtas_miscdev);
604 if (result) {
Joe Perches27c766a2012-02-15 15:06:19 -0800605 pr_err("couldn't register watchdog misc device. Terminating watchdog code.\n");
Utz Bacher031f7ed2005-06-23 09:43:34 +1000606 return result;
607 }
608
609 if (wdrtas_token_get_sensor_state != RTAS_UNKNOWN_SERVICE) {
610 result = misc_register(&wdrtas_tempdev);
611 if (result) {
Joe Perches27c766a2012-02-15 15:06:19 -0800612 pr_warn("couldn't register watchdog temperature misc device. Continuing without temperature support.\n");
Utz Bacher031f7ed2005-06-23 09:43:34 +1000613 wdrtas_token_get_sensor_state = RTAS_UNKNOWN_SERVICE;
614 }
615 }
616
617 return 0;
618}
619
620/**
621 * wdrtas_init - init function of the watchdog driver
622 *
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200623 * returns 0 on success, <0 on failure
Utz Bacher031f7ed2005-06-23 09:43:34 +1000624 *
625 * registers the file handlers and the reboot notifier
626 */
Alan Coxdae67a22008-05-19 14:09:45 +0100627static int __init wdrtas_init(void)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000628{
629 if (wdrtas_get_tokens())
630 return -ENODEV;
631
632 if (wdrtas_register_devs())
633 return -ENODEV;
634
635 if (register_reboot_notifier(&wdrtas_notifier)) {
Joe Perches27c766a2012-02-15 15:06:19 -0800636 pr_err("could not register reboot notifier. Terminating watchdog code.\n");
Utz Bacher031f7ed2005-06-23 09:43:34 +1000637 wdrtas_unregister_devs();
638 return -ENODEV;
639 }
640
641 if (wdrtas_token_get_sp == RTAS_UNKNOWN_SERVICE)
642 wdrtas_interval = WDRTAS_DEFAULT_INTERVAL;
643 else
644 wdrtas_interval = wdrtas_get_interval(WDRTAS_DEFAULT_INTERVAL);
645
646 return 0;
647}
648
649/**
650 * wdrtas_exit - exit function of the watchdog driver
651 *
652 * unregisters the file handlers and the reboot notifier
653 */
Alan Coxdae67a22008-05-19 14:09:45 +0100654static void __exit wdrtas_exit(void)
Utz Bacher031f7ed2005-06-23 09:43:34 +1000655{
656 if (!wdrtas_nowayout)
657 wdrtas_timer_stop();
658
659 wdrtas_unregister_devs();
660
661 unregister_reboot_notifier(&wdrtas_notifier);
662}
663
664module_init(wdrtas_init);
665module_exit(wdrtas_exit);