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[linux/fpc-iii.git] / drivers / char / watchdog / w83977f_wdt.c
blob2c8d5d8bd4e85303750274d1e9b2907b66c0bdad
1 /*
2 * W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip
4 * (c) Copyright 2005 Jose Goncalves <jose.goncalves@inov.pt>
6 * Based on w83877f_wdt.c by Scott Jennings,
7 * and wdt977.c by Woody Suwalski
9 * -----------------------
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/types.h>
21 #include <linux/kernel.h>
22 #include <linux/fs.h>
23 #include <linux/miscdevice.h>
24 #include <linux/init.h>
25 #include <linux/ioport.h>
26 #include <linux/watchdog.h>
27 #include <linux/notifier.h>
28 #include <linux/reboot.h>
30 #include <asm/io.h>
31 #include <asm/system.h>
32 #include <asm/uaccess.h>
34 #define WATCHDOG_VERSION "1.00"
35 #define WATCHDOG_NAME "W83977F WDT"
36 #define PFX WATCHDOG_NAME ": "
37 #define DRIVER_VERSION WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
39 #define IO_INDEX_PORT 0x3F0
40 #define IO_DATA_PORT (IO_INDEX_PORT+1)
42 #define UNLOCK_DATA 0x87
43 #define LOCK_DATA 0xAA
44 #define DEVICE_REGISTER 0x07
46 #define DEFAULT_TIMEOUT 45 /* default timeout in seconds */
48 static int timeout = DEFAULT_TIMEOUT;
49 static int timeoutW; /* timeout in watchdog counter units */
50 static unsigned long timer_alive;
51 static int testmode;
52 static char expect_close;
53 static spinlock_t spinlock;
55 module_param(timeout, int, 0);
56 MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (15..7635), default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")");
57 module_param(testmode, int, 0);
58 MODULE_PARM_DESC(testmode,"Watchdog testmode (1 = no reboot), default=0");
60 static int nowayout = WATCHDOG_NOWAYOUT;
61 module_param(nowayout, int, 0);
62 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
65 * Start the watchdog
68 static int wdt_start(void)
70 unsigned long flags;
72 spin_lock_irqsave(&spinlock, flags);
74 /* Unlock the SuperIO chip */
75 outb_p(UNLOCK_DATA,IO_INDEX_PORT);
76 outb_p(UNLOCK_DATA,IO_INDEX_PORT);
79 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
80 * F2 has the timeout in watchdog counter units.
81 * F3 is set to enable watchdog LED blink at timeout.
82 * F4 is used to just clear the TIMEOUT'ed state (bit 0).
84 outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
85 outb_p(0x08,IO_DATA_PORT);
86 outb_p(0xF2,IO_INDEX_PORT);
87 outb_p(timeoutW,IO_DATA_PORT);
88 outb_p(0xF3,IO_INDEX_PORT);
89 outb_p(0x08,IO_DATA_PORT);
90 outb_p(0xF4,IO_INDEX_PORT);
91 outb_p(0x00,IO_DATA_PORT);
93 /* Set device Aux2 active */
94 outb_p(0x30,IO_INDEX_PORT);
95 outb_p(0x01,IO_DATA_PORT);
97 /*
98 * Select device Aux1 (dev=7) to set GP16 as the watchdog output
99 * (in reg E6) and GP13 as the watchdog LED output (in reg E3).
100 * Map GP16 at pin 119.
101 * In test mode watch the bit 0 on F4 to indicate "triggered" or
102 * check watchdog LED on SBC.
104 outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
105 outb_p(0x07,IO_DATA_PORT);
106 if (!testmode)
108 unsigned pin_map;
110 outb_p(0xE6,IO_INDEX_PORT);
111 outb_p(0x0A,IO_DATA_PORT);
112 outb_p(0x2C,IO_INDEX_PORT);
113 pin_map = inb_p(IO_DATA_PORT);
114 pin_map |= 0x10;
115 pin_map &= ~(0x20);
116 outb_p(0x2C,IO_INDEX_PORT);
117 outb_p(pin_map,IO_DATA_PORT);
119 outb_p(0xE3,IO_INDEX_PORT);
120 outb_p(0x08,IO_DATA_PORT);
122 /* Set device Aux1 active */
123 outb_p(0x30,IO_INDEX_PORT);
124 outb_p(0x01,IO_DATA_PORT);
126 /* Lock the SuperIO chip */
127 outb_p(LOCK_DATA,IO_INDEX_PORT);
129 spin_unlock_irqrestore(&spinlock, flags);
131 printk(KERN_INFO PFX "activated.\n");
133 return 0;
137 * Stop the watchdog
140 static int wdt_stop(void)
142 unsigned long flags;
144 spin_lock_irqsave(&spinlock, flags);
146 /* Unlock the SuperIO chip */
147 outb_p(UNLOCK_DATA,IO_INDEX_PORT);
148 outb_p(UNLOCK_DATA,IO_INDEX_PORT);
151 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
152 * F2 is reset to its default value (watchdog timer disabled).
153 * F3 is reset to its default state.
154 * F4 clears the TIMEOUT'ed state (bit 0) - back to default.
156 outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
157 outb_p(0x08,IO_DATA_PORT);
158 outb_p(0xF2,IO_INDEX_PORT);
159 outb_p(0xFF,IO_DATA_PORT);
160 outb_p(0xF3,IO_INDEX_PORT);
161 outb_p(0x00,IO_DATA_PORT);
162 outb_p(0xF4,IO_INDEX_PORT);
163 outb_p(0x00,IO_DATA_PORT);
164 outb_p(0xF2,IO_INDEX_PORT);
165 outb_p(0x00,IO_DATA_PORT);
168 * Select device Aux1 (dev=7) to set GP16 (in reg E6) and
169 * Gp13 (in reg E3) as inputs.
171 outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
172 outb_p(0x07,IO_DATA_PORT);
173 if (!testmode)
175 outb_p(0xE6,IO_INDEX_PORT);
176 outb_p(0x01,IO_DATA_PORT);
178 outb_p(0xE3,IO_INDEX_PORT);
179 outb_p(0x01,IO_DATA_PORT);
181 /* Lock the SuperIO chip */
182 outb_p(LOCK_DATA,IO_INDEX_PORT);
184 spin_unlock_irqrestore(&spinlock, flags);
186 printk(KERN_INFO PFX "shutdown.\n");
188 return 0;
192 * Send a keepalive ping to the watchdog
193 * This is done by simply re-writing the timeout to reg. 0xF2
196 static int wdt_keepalive(void)
198 unsigned long flags;
200 spin_lock_irqsave(&spinlock, flags);
202 /* Unlock the SuperIO chip */
203 outb_p(UNLOCK_DATA,IO_INDEX_PORT);
204 outb_p(UNLOCK_DATA,IO_INDEX_PORT);
206 /* Select device Aux2 (device=8) to kick watchdog reg F2 */
207 outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
208 outb_p(0x08,IO_DATA_PORT);
209 outb_p(0xF2,IO_INDEX_PORT);
210 outb_p(timeoutW,IO_DATA_PORT);
212 /* Lock the SuperIO chip */
213 outb_p(LOCK_DATA,IO_INDEX_PORT);
215 spin_unlock_irqrestore(&spinlock, flags);
217 return 0;
221 * Set the watchdog timeout value
224 static int wdt_set_timeout(int t)
226 int tmrval;
229 * Convert seconds to watchdog counter time units, rounding up.
230 * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup
231 * value. This information is supplied in the PCM-5335 manual and was
232 * checked by me on a real board. This is a bit strange because W83977f
233 * datasheet says counter unit is in minutes!
235 if (t < 15)
236 return -EINVAL;
238 tmrval = ((t + 15) + 29) / 30;
240 if (tmrval > 255)
241 return -EINVAL;
244 * timeout is the timeout in seconds,
245 * timeoutW is the timeout in watchdog counter units.
247 timeoutW = tmrval;
248 timeout = (timeoutW * 30) - 15;
249 return 0;
253 * Get the watchdog status
256 static int wdt_get_status(int *status)
258 int new_status;
259 unsigned long flags;
261 spin_lock_irqsave(&spinlock, flags);
263 /* Unlock the SuperIO chip */
264 outb_p(UNLOCK_DATA,IO_INDEX_PORT);
265 outb_p(UNLOCK_DATA,IO_INDEX_PORT);
267 /* Select device Aux2 (device=8) to read watchdog reg F4 */
268 outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
269 outb_p(0x08,IO_DATA_PORT);
270 outb_p(0xF4,IO_INDEX_PORT);
271 new_status = inb_p(IO_DATA_PORT);
273 /* Lock the SuperIO chip */
274 outb_p(LOCK_DATA,IO_INDEX_PORT);
276 spin_unlock_irqrestore(&spinlock, flags);
278 *status = 0;
279 if (new_status & 1)
280 *status |= WDIOF_CARDRESET;
282 return 0;
287 * /dev/watchdog handling
290 static int wdt_open(struct inode *inode, struct file *file)
292 /* If the watchdog is alive we don't need to start it again */
293 if( test_and_set_bit(0, &timer_alive) )
294 return -EBUSY;
296 if (nowayout)
297 __module_get(THIS_MODULE);
299 wdt_start();
300 return nonseekable_open(inode, file);
303 static int wdt_release(struct inode *inode, struct file *file)
306 * Shut off the timer.
307 * Lock it in if it's a module and we set nowayout
309 if (expect_close == 42)
311 wdt_stop();
312 clear_bit(0, &timer_alive);
313 } else {
314 wdt_keepalive();
315 printk(KERN_CRIT PFX "unexpected close, not stopping watchdog!\n");
317 expect_close = 0;
318 return 0;
322 * wdt_write:
323 * @file: file handle to the watchdog
324 * @buf: buffer to write (unused as data does not matter here
325 * @count: count of bytes
326 * @ppos: pointer to the position to write. No seeks allowed
328 * A write to a watchdog device is defined as a keepalive signal. Any
329 * write of data will do, as we we don't define content meaning.
332 static ssize_t wdt_write(struct file *file, const char __user *buf,
333 size_t count, loff_t *ppos)
335 /* See if we got the magic character 'V' and reload the timer */
336 if(count)
338 if (!nowayout)
340 size_t ofs;
342 /* note: just in case someone wrote the magic character long ago */
343 expect_close = 0;
345 /* scan to see whether or not we got the magic character */
346 for(ofs = 0; ofs != count; ofs++)
348 char c;
349 if (get_user(c, buf + ofs))
350 return -EFAULT;
351 if (c == 'V') {
352 expect_close = 42;
357 /* someone wrote to us, we should restart timer */
358 wdt_keepalive();
360 return count;
364 * wdt_ioctl:
365 * @inode: inode of the device
366 * @file: file handle to the device
367 * @cmd: watchdog command
368 * @arg: argument pointer
370 * The watchdog API defines a common set of functions for all watchdogs
371 * according to their available features.
374 static struct watchdog_info ident = {
375 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
376 .firmware_version = 1,
377 .identity = WATCHDOG_NAME,
380 static int wdt_ioctl(struct inode *inode, struct file *file,
381 unsigned int cmd, unsigned long arg)
383 int status;
384 int new_options, retval = -EINVAL;
385 int new_timeout;
386 union {
387 struct watchdog_info __user *ident;
388 int __user *i;
389 } uarg;
391 uarg.i = (int __user *)arg;
393 switch(cmd)
395 default:
396 return -ENOTTY;
398 case WDIOC_GETSUPPORT:
399 return copy_to_user(uarg.ident, &ident, sizeof(ident)) ? -EFAULT : 0;
401 case WDIOC_GETSTATUS:
402 wdt_get_status(&status);
403 return put_user(status, uarg.i);
405 case WDIOC_GETBOOTSTATUS:
406 return put_user(0, uarg.i);
408 case WDIOC_KEEPALIVE:
409 wdt_keepalive();
410 return 0;
412 case WDIOC_SETOPTIONS:
413 if (get_user (new_options, uarg.i))
414 return -EFAULT;
416 if (new_options & WDIOS_DISABLECARD) {
417 wdt_stop();
418 retval = 0;
421 if (new_options & WDIOS_ENABLECARD) {
422 wdt_start();
423 retval = 0;
426 return retval;
428 case WDIOC_SETTIMEOUT:
429 if (get_user(new_timeout, uarg.i))
430 return -EFAULT;
432 if (wdt_set_timeout(new_timeout))
433 return -EINVAL;
435 wdt_keepalive();
436 /* Fall */
438 case WDIOC_GETTIMEOUT:
439 return put_user(timeout, uarg.i);
444 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
445 void *unused)
447 if (code==SYS_DOWN || code==SYS_HALT)
448 wdt_stop();
449 return NOTIFY_DONE;
452 static const struct file_operations wdt_fops=
454 .owner = THIS_MODULE,
455 .llseek = no_llseek,
456 .write = wdt_write,
457 .ioctl = wdt_ioctl,
458 .open = wdt_open,
459 .release = wdt_release,
462 static struct miscdevice wdt_miscdev=
464 .minor = WATCHDOG_MINOR,
465 .name = "watchdog",
466 .fops = &wdt_fops,
469 static struct notifier_block wdt_notifier = {
470 .notifier_call = wdt_notify_sys,
473 static int __init w83977f_wdt_init(void)
475 int rc;
477 printk(KERN_INFO PFX DRIVER_VERSION);
479 spin_lock_init(&spinlock);
482 * Check that the timeout value is within it's range ;
483 * if not reset to the default
485 if (wdt_set_timeout(timeout)) {
486 wdt_set_timeout(DEFAULT_TIMEOUT);
487 printk(KERN_INFO PFX "timeout value must be 15<=timeout<=7635, using %d\n",
488 DEFAULT_TIMEOUT);
491 if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME))
493 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
494 IO_INDEX_PORT);
495 rc = -EIO;
496 goto err_out;
499 rc = misc_register(&wdt_miscdev);
500 if (rc)
502 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
503 wdt_miscdev.minor, rc);
504 goto err_out_region;
507 rc = register_reboot_notifier(&wdt_notifier);
508 if (rc)
510 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
511 rc);
512 goto err_out_miscdev;
515 printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
516 timeout, nowayout, testmode);
518 return 0;
520 err_out_miscdev:
521 misc_deregister(&wdt_miscdev);
522 err_out_region:
523 release_region(IO_INDEX_PORT,2);
524 err_out:
525 return rc;
528 static void __exit w83977f_wdt_exit(void)
530 wdt_stop();
531 misc_deregister(&wdt_miscdev);
532 unregister_reboot_notifier(&wdt_notifier);
533 release_region(IO_INDEX_PORT,2);
536 module_init(w83977f_wdt_init);
537 module_exit(w83977f_wdt_exit);
539 MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
540 MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
541 MODULE_LICENSE("GPL");
542 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);