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authorWim Van Sebroeck <wim@iguana.be>2007-08-17 04:38:02 -0400
committerWim Van Sebroeck <wim@iguana.be>2007-10-18 06:39:03 -0400
commitb7e04f8c61a46d742de23af5d7ca2b41b33e40ac (patch)
treec52a7ea568648e2d8ed0d423098b42298de2058b /drivers/watchdog/smsc37b787_wdt.c
parentd85714d81cc0408daddb68c10f7fd69eafe7c213 (diff)
mv watchdog tree under drivers
move watchdog tree from drivers/char/watchdog to drivers/watchdog. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/smsc37b787_wdt.c')
-rw-r--r--drivers/watchdog/smsc37b787_wdt.c627
1 files changed, 627 insertions, 0 deletions
diff --git a/drivers/watchdog/smsc37b787_wdt.c b/drivers/watchdog/smsc37b787_wdt.c
new file mode 100644
index 00000000000..d3cb0a76602
--- /dev/null
+++ b/drivers/watchdog/smsc37b787_wdt.c
@@ -0,0 +1,627 @@
1/*
2 * SMsC 37B787 Watchdog Timer driver for Linux 2.6.x.x
3 *
4 * Based on acquirewdt.c by Alan Cox <alan@redhat.com>
5 * and some other existing drivers
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * The authors do NOT admit liability nor provide warranty for
13 * any of this software. This material is provided "AS-IS" in
14 * the hope that it may be useful for others.
15 *
16 * (C) Copyright 2003-2006 Sven Anders <anders@anduras.de>
17 *
18 * History:
19 * 2003 - Created version 1.0 for Linux 2.4.x.
20 * 2006 - Ported to Linux 2.6, added nowayout and MAGICCLOSE
21 * features. Released version 1.1
22 *
23 * Theory of operation:
24 *
25 * A Watchdog Timer (WDT) is a hardware circuit that can
26 * reset the computer system in case of a software fault.
27 * You probably knew that already.
28 *
29 * Usually a userspace daemon will notify the kernel WDT driver
30 * via the /dev/watchdog special device file that userspace is
31 * still alive, at regular intervals. When such a notification
32 * occurs, the driver will usually tell the hardware watchdog
33 * that everything is in order, and that the watchdog should wait
34 * for yet another little while to reset the system.
35 * If userspace fails (RAM error, kernel bug, whatever), the
36 * notifications cease to occur, and the hardware watchdog will
37 * reset the system (causing a reboot) after the timeout occurs.
38 *
39 * Create device with:
40 * mknod /dev/watchdog c 10 130
41 *
42 * For an example userspace keep-alive daemon, see:
43 * Documentation/watchdog/watchdog.txt
44 */
45
46#include <linux/module.h>
47#include <linux/moduleparam.h>
48#include <linux/types.h>
49#include <linux/miscdevice.h>
50#include <linux/watchdog.h>
51#include <linux/delay.h>
52#include <linux/fs.h>
53#include <linux/ioport.h>
54#include <linux/notifier.h>
55#include <linux/reboot.h>
56#include <linux/init.h>
57#include <linux/spinlock.h>
58
59#include <asm/io.h>
60#include <asm/uaccess.h>
61#include <asm/system.h>
62
63/* enable support for minutes as units? */
64/* (does not always work correctly, so disabled by default!) */
65#define SMSC_SUPPORT_MINUTES
66#undef SMSC_SUPPORT_MINUTES
67
68#define MAX_TIMEOUT 255
69
70#define UNIT_SECOND 0
71#define UNIT_MINUTE 1
72
73#define MODNAME "smsc37b787_wdt: "
74#define VERSION "1.1"
75
76#define IOPORT 0x3F0
77#define IOPORT_SIZE 2
78#define IODEV_NO 8
79
80static int unit = UNIT_SECOND; /* timer's unit */
81static int timeout = 60; /* timeout value: default is 60 "units" */
82static unsigned long timer_enabled = 0; /* is the timer enabled? */
83
84static char expect_close; /* is the close expected? */
85
86static spinlock_t io_lock; /* to guard the watchdog from io races */
87
88static int nowayout = WATCHDOG_NOWAYOUT;
89
90/* -- Low level function ----------------------------------------*/
91
92/* unlock the IO chip */
93
94static inline void open_io_config(void)
95{
96 outb(0x55, IOPORT);
97 mdelay(1);
98 outb(0x55, IOPORT);
99}
100
101/* lock the IO chip */
102static inline void close_io_config(void)
103{
104 outb(0xAA, IOPORT);
105}
106
107/* select the IO device */
108static inline void select_io_device(unsigned char devno)
109{
110 outb(0x07, IOPORT);
111 outb(devno, IOPORT+1);
112}
113
114/* write to the control register */
115static inline void write_io_cr(unsigned char reg, unsigned char data)
116{
117 outb(reg, IOPORT);
118 outb(data, IOPORT+1);
119}
120
121/* read from the control register */
122static inline char read_io_cr(unsigned char reg)
123{
124 outb(reg, IOPORT);
125 return inb(IOPORT+1);
126}
127
128/* -- Medium level functions ------------------------------------*/
129
130static inline void gpio_bit12(unsigned char reg)
131{
132 // -- General Purpose I/O Bit 1.2 --
133 // Bit 0, In/Out: 0 = Output, 1 = Input
134 // Bit 1, Polarity: 0 = No Invert, 1 = Invert
135 // Bit 2, Group Enable Intr.: 0 = Disable, 1 = Enable
136 // Bit 3/4, Function select: 00 = GPI/O, 01 = WDT, 10 = P17,
137 // 11 = Either Edge Triggered Intr. 2
138 // Bit 5/6 (Reserved)
139 // Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
140 write_io_cr(0xE2, reg);
141}
142
143static inline void gpio_bit13(unsigned char reg)
144{
145 // -- General Purpose I/O Bit 1.3 --
146 // Bit 0, In/Out: 0 = Output, 1 = Input
147 // Bit 1, Polarity: 0 = No Invert, 1 = Invert
148 // Bit 2, Group Enable Intr.: 0 = Disable, 1 = Enable
149 // Bit 3, Function select: 0 = GPI/O, 1 = LED
150 // Bit 4-6 (Reserved)
151 // Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
152 write_io_cr(0xE3, reg);
153}
154
155static inline void wdt_timer_units(unsigned char new_units)
156{
157 // -- Watchdog timer units --
158 // Bit 0-6 (Reserved)
159 // Bit 7, WDT Time-out Value Units Select
160 // (0 = Minutes, 1 = Seconds)
161 write_io_cr(0xF1, new_units);
162}
163
164static inline void wdt_timeout_value(unsigned char new_timeout)
165{
166 // -- Watchdog Timer Time-out Value --
167 // Bit 0-7 Binary coded units (0=Disabled, 1..255)
168 write_io_cr(0xF2, new_timeout);
169}
170
171static inline void wdt_timer_conf(unsigned char conf)
172{
173 // -- Watchdog timer configuration --
174 // Bit 0 Joystick enable: 0* = No Reset, 1 = Reset WDT upon Gameport I/O
175 // Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
176 // Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr.
177 // Bit 3 Reset the timer
178 // (Wrong in SMsC documentation? Given as: PowerLED Timout Enabled)
179 // Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
180 // 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
181 write_io_cr(0xF3, conf);
182}
183
184static inline void wdt_timer_ctrl(unsigned char reg)
185{
186 // -- Watchdog timer control --
187 // Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occured
188 // Bit 1 Power LED Toggle: 0 = Disable Toggle, 1 = Toggle at 1 Hz
189 // Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning)
190 // Bit 3 P20 Force Timeout enabled:
191 // 0 = P20 activity does not generate the WD timeout event
192 // 1 = P20 Allows rising edge of P20, from the keyboard
193 // controller, to force the WD timeout event.
194 // Bit 4 (Reserved)
195 // -- Soft power management --
196 // Bit 5 Stop Counter: 1 = Stop software power down counter
197 // set via register 0xB8, (self-cleaning)
198 // (Upon read: 0 = Counter running, 1 = Counter stopped)
199 // Bit 6 Restart Counter: 1 = Restart software power down counter
200 // set via register 0xB8, (self-cleaning)
201 // Bit 7 SPOFF: 1 = Force software power down (self-cleaning)
202
203 write_io_cr(0xF4, reg);
204}
205
206/* -- Higher level functions ------------------------------------*/
207
208/* initialize watchdog */
209
210static void wb_smsc_wdt_initialize(void)
211{
212 unsigned char old;
213
214 spin_lock(&io_lock);
215 open_io_config();
216 select_io_device(IODEV_NO);
217
218 // enable the watchdog
219 gpio_bit13(0x08); // Select pin 80 = LED not GPIO
220 gpio_bit12(0x0A); // Set pin 79 = WDT not GPIO/Output/Polarity=Invert
221
222 // disable the timeout
223 wdt_timeout_value(0);
224
225 // reset control register
226 wdt_timer_ctrl(0x00);
227
228 // reset configuration register
229 wdt_timer_conf(0x00);
230
231 // read old (timer units) register
232 old = read_io_cr(0xF1) & 0x7F;
233 if (unit == UNIT_SECOND) old |= 0x80; // set to seconds
234
235 // set the watchdog timer units
236 wdt_timer_units(old);
237
238 close_io_config();
239 spin_unlock(&io_lock);
240}
241
242/* shutdown the watchdog */
243
244static void wb_smsc_wdt_shutdown(void)
245{
246 spin_lock(&io_lock);
247 open_io_config();
248 select_io_device(IODEV_NO);
249
250 // disable the watchdog
251 gpio_bit13(0x09);
252 gpio_bit12(0x09);
253
254 // reset watchdog config register
255 wdt_timer_conf(0x00);
256
257 // reset watchdog control register
258 wdt_timer_ctrl(0x00);
259
260 // disable timeout
261 wdt_timeout_value(0x00);
262
263 close_io_config();
264 spin_unlock(&io_lock);
265}
266
267/* set timeout => enable watchdog */
268
269static void wb_smsc_wdt_set_timeout(unsigned char new_timeout)
270{
271 spin_lock(&io_lock);
272 open_io_config();
273 select_io_device(IODEV_NO);
274
275 // set Power LED to blink, if we enable the timeout
276 wdt_timer_ctrl((new_timeout == 0) ? 0x00 : 0x02);
277
278 // set timeout value
279 wdt_timeout_value(new_timeout);
280
281 close_io_config();
282 spin_unlock(&io_lock);
283}
284
285/* get timeout */
286
287static unsigned char wb_smsc_wdt_get_timeout(void)
288{
289 unsigned char set_timeout;
290
291 spin_lock(&io_lock);
292 open_io_config();
293 select_io_device(IODEV_NO);
294 set_timeout = read_io_cr(0xF2);
295 close_io_config();
296 spin_unlock(&io_lock);
297
298 return set_timeout;
299}
300
301/* disable watchdog */
302
303static void wb_smsc_wdt_disable(void)
304{
305 // set the timeout to 0 to disable the watchdog
306 wb_smsc_wdt_set_timeout(0);
307}
308
309/* enable watchdog by setting the current timeout */
310
311static void wb_smsc_wdt_enable(void)
312{
313 // set the current timeout...
314 wb_smsc_wdt_set_timeout(timeout);
315}
316
317/* reset the timer */
318
319static void wb_smsc_wdt_reset_timer(void)
320{
321 spin_lock(&io_lock);
322 open_io_config();
323 select_io_device(IODEV_NO);
324
325 // reset the timer
326 wdt_timeout_value(timeout);
327 wdt_timer_conf(0x08);
328
329 close_io_config();
330 spin_unlock(&io_lock);
331}
332
333/* return, if the watchdog is enabled (timeout is set...) */
334
335static int wb_smsc_wdt_status(void)
336{
337 return (wb_smsc_wdt_get_timeout() == 0) ? 0 : WDIOF_KEEPALIVEPING;
338}
339
340
341/* -- File operations -------------------------------------------*/
342
343/* open => enable watchdog and set initial timeout */
344
345static int wb_smsc_wdt_open(struct inode *inode, struct file *file)
346{
347 /* /dev/watchdog can only be opened once */
348
349 if (test_and_set_bit(0, &timer_enabled))
350 return -EBUSY;
351
352 if (nowayout)
353 __module_get(THIS_MODULE);
354
355 /* Reload and activate timer */
356 wb_smsc_wdt_enable();
357
358 printk(KERN_INFO MODNAME "Watchdog enabled. Timeout set to %d %s.\n", timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");
359
360 return nonseekable_open(inode, file);
361}
362
363/* close => shut off the timer */
364
365static int wb_smsc_wdt_release(struct inode *inode, struct file *file)
366{
367 /* Shut off the timer. */
368
369 if (expect_close == 42) {
370 wb_smsc_wdt_disable();
371 printk(KERN_INFO MODNAME "Watchdog disabled, sleeping again...\n");
372 } else {
373 printk(KERN_CRIT MODNAME "Unexpected close, not stopping watchdog!\n");
374 wb_smsc_wdt_reset_timer();
375 }
376
377 clear_bit(0, &timer_enabled);
378 expect_close = 0;
379 return 0;
380}
381
382/* write => update the timer to keep the machine alive */
383
384static ssize_t wb_smsc_wdt_write(struct file *file, const char __user *data,
385 size_t len, loff_t *ppos)
386{
387 /* See if we got the magic character 'V' and reload the timer */
388 if (len) {
389 if (!nowayout) {
390 size_t i;
391
392 /* reset expect flag */
393 expect_close = 0;
394
395 /* scan to see whether or not we got the magic character */
396 for (i = 0; i != len; i++) {
397 char c;
398 if (get_user(c, data+i))
399 return -EFAULT;
400 if (c == 'V')
401 expect_close = 42;
402 }
403 }
404
405 /* someone wrote to us, we should reload the timer */
406 wb_smsc_wdt_reset_timer();
407 }
408 return len;
409}
410
411/* ioctl => control interface */
412
413static int wb_smsc_wdt_ioctl(struct inode *inode, struct file *file,
414 unsigned int cmd, unsigned long arg)
415{
416 int new_timeout;
417
418 union {
419 struct watchdog_info __user *ident;
420 int __user *i;
421 } uarg;
422
423 static struct watchdog_info ident = {
424 .options = WDIOF_KEEPALIVEPING |
425 WDIOF_SETTIMEOUT |
426 WDIOF_MAGICCLOSE,
427 .firmware_version = 0,
428 .identity = "SMsC 37B787 Watchdog"
429 };
430
431 uarg.i = (int __user *)arg;
432
433 switch (cmd) {
434 default:
435 return -ENOTTY;
436
437 case WDIOC_GETSUPPORT:
438 return copy_to_user(uarg.ident, &ident,
439 sizeof(ident)) ? -EFAULT : 0;
440
441 case WDIOC_GETSTATUS:
442 return put_user(wb_smsc_wdt_status(), uarg.i);
443
444 case WDIOC_GETBOOTSTATUS:
445 return put_user(0, uarg.i);
446
447 case WDIOC_KEEPALIVE:
448 wb_smsc_wdt_reset_timer();
449 return 0;
450
451 case WDIOC_SETTIMEOUT:
452 if (get_user(new_timeout, uarg.i))
453 return -EFAULT;
454
455 // the API states this is given in secs
456 if (unit == UNIT_MINUTE)
457 new_timeout /= 60;
458
459 if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
460 return -EINVAL;
461
462 timeout = new_timeout;
463 wb_smsc_wdt_set_timeout(timeout);
464
465 // fall through and return the new timeout...
466
467 case WDIOC_GETTIMEOUT:
468
469 new_timeout = timeout;
470
471 if (unit == UNIT_MINUTE)
472 new_timeout *= 60;
473
474 return put_user(new_timeout, uarg.i);
475
476 case WDIOC_SETOPTIONS:
477 {
478 int options, retval = -EINVAL;
479
480 if (get_user(options, uarg.i))
481 return -EFAULT;
482
483 if (options & WDIOS_DISABLECARD) {
484 wb_smsc_wdt_disable();
485 retval = 0;
486 }
487
488 if (options & WDIOS_ENABLECARD) {
489 wb_smsc_wdt_enable();
490 retval = 0;
491 }
492
493 return retval;
494 }
495 }
496}
497
498/* -- Notifier funtions -----------------------------------------*/
499
500static int wb_smsc_wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
501{
502 if (code == SYS_DOWN || code == SYS_HALT)
503 {
504 // set timeout to 0, to avoid possible race-condition
505 timeout = 0;
506 wb_smsc_wdt_disable();
507 }
508 return NOTIFY_DONE;
509}
510
511/* -- Module's structures ---------------------------------------*/
512
513static const struct file_operations wb_smsc_wdt_fops =
514{
515 .owner = THIS_MODULE,
516 .llseek = no_llseek,
517 .write = wb_smsc_wdt_write,
518 .ioctl = wb_smsc_wdt_ioctl,
519 .open = wb_smsc_wdt_open,
520 .release = wb_smsc_wdt_release,
521};
522
523static struct notifier_block wb_smsc_wdt_notifier =
524{
525 .notifier_call = wb_smsc_wdt_notify_sys,
526};
527
528static struct miscdevice wb_smsc_wdt_miscdev =
529{
530 .minor = WATCHDOG_MINOR,
531 .name = "watchdog",
532 .fops = &wb_smsc_wdt_fops,
533};
534
535/* -- Module init functions -------------------------------------*/
536
537/* module's "constructor" */
538
539static int __init wb_smsc_wdt_init(void)
540{
541 int ret;
542
543 spin_lock_init(&io_lock);
544
545 printk("SMsC 37B787 watchdog component driver " VERSION " initialising...\n");
546
547 if (!request_region(IOPORT, IOPORT_SIZE, "SMsC 37B787 watchdog")) {
548 printk(KERN_ERR MODNAME "Unable to register IO port %#x\n", IOPORT);
549 ret = -EBUSY;
550 goto out_pnp;
551 }
552
553 // set new maximum, if it's too big
554 if (timeout > MAX_TIMEOUT)
555 timeout = MAX_TIMEOUT;
556
557 // init the watchdog timer
558 wb_smsc_wdt_initialize();
559
560 ret = register_reboot_notifier(&wb_smsc_wdt_notifier);
561 if (ret) {
562 printk(KERN_ERR MODNAME "Unable to register reboot notifier err = %d\n", ret);
563 goto out_io;
564 }
565
566 ret = misc_register(&wb_smsc_wdt_miscdev);
567 if (ret) {
568 printk(KERN_ERR MODNAME "Unable to register miscdev on minor %d\n", WATCHDOG_MINOR);
569 goto out_rbt;
570 }
571
572 // output info
573 printk(KERN_INFO MODNAME "Timeout set to %d %s.\n", timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");
574 printk(KERN_INFO MODNAME "Watchdog initialized and sleeping (nowayout=%d)...\n", nowayout);
575
576 // ret = 0
577
578out_clean:
579 return ret;
580
581out_rbt:
582 unregister_reboot_notifier(&wb_smsc_wdt_notifier);
583
584out_io:
585 release_region(IOPORT, IOPORT_SIZE);
586
587out_pnp:
588 goto out_clean;
589}
590
591/* module's "destructor" */
592
593static void __exit wb_smsc_wdt_exit(void)
594{
595 /* Stop the timer before we leave */
596 if (!nowayout)
597 {
598 wb_smsc_wdt_shutdown();
599 printk(KERN_INFO MODNAME "Watchdog disabled.\n");
600 }
601
602 misc_deregister(&wb_smsc_wdt_miscdev);
603 unregister_reboot_notifier(&wb_smsc_wdt_notifier);
604 release_region(IOPORT, IOPORT_SIZE);
605
606 printk("SMsC 37B787 watchdog component driver removed.\n");
607}
608
609module_init(wb_smsc_wdt_init);
610module_exit(wb_smsc_wdt_exit);
611
612MODULE_AUTHOR("Sven Anders <anders@anduras.de>");
613MODULE_DESCRIPTION("Driver for SMsC 37B787 watchdog component (Version " VERSION ")");
614MODULE_LICENSE("GPL");
615
616MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
617
618#ifdef SMSC_SUPPORT_MINUTES
619module_param(unit, int, 0);
620MODULE_PARM_DESC(unit, "set unit to use, 0=seconds or 1=minutes, default is 0");
621#endif
622
623module_param(timeout, int, 0);
624MODULE_PARM_DESC(timeout, "range is 1-255 units, default is 60");
625
626module_param(nowayout, int, 0);
627MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");