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>
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>
29 #include <linux/uaccess.h>
32 #include <asm/system.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;
52 static char expect_close;
53 static DEFINE_SPINLOCK(spinlock);
55 module_param(timeout, int, 0);
56 MODULE_PARM_DESC(timeout,
57 "Watchdog timeout in seconds (15..7635), default="
58 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
59 module_param(testmode, int, 0);
60 MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
62 static int nowayout = WATCHDOG_NOWAYOUT;
63 module_param(nowayout, int, 0);
64 MODULE_PARM_DESC(nowayout,
65 "Watchdog cannot be stopped once started (default="
66 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
72 static int wdt_start(void)
76 spin_lock_irqsave(&spinlock, flags);
78 /* Unlock the SuperIO chip */
79 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
80 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
83 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
84 * F2 has the timeout in watchdog counter units.
85 * F3 is set to enable watchdog LED blink at timeout.
86 * F4 is used to just clear the TIMEOUT'ed state (bit 0).
88 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
89 outb_p(0x08, IO_DATA_PORT);
90 outb_p(0xF2, IO_INDEX_PORT);
91 outb_p(timeoutW, IO_DATA_PORT);
92 outb_p(0xF3, IO_INDEX_PORT);
93 outb_p(0x08, IO_DATA_PORT);
94 outb_p(0xF4, IO_INDEX_PORT);
95 outb_p(0x00, IO_DATA_PORT);
97 /* Set device Aux2 active */
98 outb_p(0x30, IO_INDEX_PORT);
99 outb_p(0x01, IO_DATA_PORT);
102 * Select device Aux1 (dev=7) to set GP16 as the watchdog output
103 * (in reg E6) and GP13 as the watchdog LED output (in reg E3).
104 * Map GP16 at pin 119.
105 * In test mode watch the bit 0 on F4 to indicate "triggered" or
106 * check watchdog LED on SBC.
108 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
109 outb_p(0x07, IO_DATA_PORT);
113 outb_p(0xE6, IO_INDEX_PORT);
114 outb_p(0x0A, IO_DATA_PORT);
115 outb_p(0x2C, IO_INDEX_PORT);
116 pin_map = inb_p(IO_DATA_PORT);
119 outb_p(0x2C, IO_INDEX_PORT);
120 outb_p(pin_map, IO_DATA_PORT);
122 outb_p(0xE3, IO_INDEX_PORT);
123 outb_p(0x08, IO_DATA_PORT);
125 /* Set device Aux1 active */
126 outb_p(0x30, IO_INDEX_PORT);
127 outb_p(0x01, IO_DATA_PORT);
129 /* Lock the SuperIO chip */
130 outb_p(LOCK_DATA, IO_INDEX_PORT);
132 spin_unlock_irqrestore(&spinlock, flags);
134 printk(KERN_INFO PFX "activated.\n");
143 static int wdt_stop(void)
147 spin_lock_irqsave(&spinlock, flags);
149 /* Unlock the SuperIO chip */
150 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
151 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
154 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
155 * F2 is reset to its default value (watchdog timer disabled).
156 * F3 is reset to its default state.
157 * F4 clears the TIMEOUT'ed state (bit 0) - back to default.
159 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
160 outb_p(0x08, IO_DATA_PORT);
161 outb_p(0xF2, IO_INDEX_PORT);
162 outb_p(0xFF, IO_DATA_PORT);
163 outb_p(0xF3, IO_INDEX_PORT);
164 outb_p(0x00, IO_DATA_PORT);
165 outb_p(0xF4, IO_INDEX_PORT);
166 outb_p(0x00, IO_DATA_PORT);
167 outb_p(0xF2, IO_INDEX_PORT);
168 outb_p(0x00, IO_DATA_PORT);
171 * Select device Aux1 (dev=7) to set GP16 (in reg E6) and
172 * Gp13 (in reg E3) as inputs.
174 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
175 outb_p(0x07, IO_DATA_PORT);
177 outb_p(0xE6, IO_INDEX_PORT);
178 outb_p(0x01, IO_DATA_PORT);
180 outb_p(0xE3, IO_INDEX_PORT);
181 outb_p(0x01, IO_DATA_PORT);
183 /* Lock the SuperIO chip */
184 outb_p(LOCK_DATA, IO_INDEX_PORT);
186 spin_unlock_irqrestore(&spinlock, flags);
188 printk(KERN_INFO PFX "shutdown.\n");
194 * Send a keepalive ping to the watchdog
195 * This is done by simply re-writing the timeout to reg. 0xF2
198 static int wdt_keepalive(void)
202 spin_lock_irqsave(&spinlock, flags);
204 /* Unlock the SuperIO chip */
205 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
206 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
208 /* Select device Aux2 (device=8) to kick watchdog reg F2 */
209 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
210 outb_p(0x08, IO_DATA_PORT);
211 outb_p(0xF2, IO_INDEX_PORT);
212 outb_p(timeoutW, IO_DATA_PORT);
214 /* Lock the SuperIO chip */
215 outb_p(LOCK_DATA, IO_INDEX_PORT);
217 spin_unlock_irqrestore(&spinlock, flags);
223 * Set the watchdog timeout value
226 static int wdt_set_timeout(int t)
231 * Convert seconds to watchdog counter time units, rounding up.
232 * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup
233 * value. This information is supplied in the PCM-5335 manual and was
234 * checked by me on a real board. This is a bit strange because W83977f
235 * datasheet says counter unit is in minutes!
240 tmrval = ((t + 15) + 29) / 30;
246 * timeout is the timeout in seconds,
247 * timeoutW is the timeout in watchdog counter units.
250 timeout = (timeoutW * 30) - 15;
255 * Get the watchdog status
258 static int wdt_get_status(int *status)
263 spin_lock_irqsave(&spinlock, flags);
265 /* Unlock the SuperIO chip */
266 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
267 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
269 /* Select device Aux2 (device=8) to read watchdog reg F4 */
270 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
271 outb_p(0x08, IO_DATA_PORT);
272 outb_p(0xF4, IO_INDEX_PORT);
273 new_status = inb_p(IO_DATA_PORT);
275 /* Lock the SuperIO chip */
276 outb_p(LOCK_DATA, IO_INDEX_PORT);
278 spin_unlock_irqrestore(&spinlock, flags);
282 *status |= WDIOF_CARDRESET;
289 * /dev/watchdog handling
292 static int wdt_open(struct inode *inode, struct file *file)
294 /* If the watchdog is alive we don't need to start it again */
295 if (test_and_set_bit(0, &timer_alive))
299 __module_get(THIS_MODULE);
302 return nonseekable_open(inode, file);
305 static int wdt_release(struct inode *inode, struct file *file)
308 * Shut off the timer.
309 * Lock it in if it's a module and we set nowayout
311 if (expect_close == 42) {
313 clear_bit(0, &timer_alive);
317 "unexpected close, not stopping watchdog!\n");
325 * @file: file handle to the watchdog
326 * @buf: buffer to write (unused as data does not matter here
327 * @count: count of bytes
328 * @ppos: pointer to the position to write. No seeks allowed
330 * A write to a watchdog device is defined as a keepalive signal. Any
331 * write of data will do, as we we don't define content meaning.
334 static ssize_t wdt_write(struct file *file, const char __user *buf,
335 size_t count, loff_t *ppos)
337 /* See if we got the magic character 'V' and reload the timer */
342 /* note: just in case someone wrote the
343 magic character long ago */
346 /* scan to see whether or not we got the
348 for (ofs = 0; ofs != count; ofs++) {
350 if (get_user(c, buf + ofs))
357 /* someone wrote to us, we should restart timer */
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 long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
383 int new_options, retval = -EINVAL;
386 struct watchdog_info __user *ident;
390 uarg.i = (int __user *)arg;
393 case WDIOC_GETSUPPORT:
394 return copy_to_user(uarg.ident, &ident,
395 sizeof(ident)) ? -EFAULT : 0;
397 case WDIOC_GETSTATUS:
398 wdt_get_status(&status);
399 return put_user(status, uarg.i);
401 case WDIOC_GETBOOTSTATUS:
402 return put_user(0, uarg.i);
404 case WDIOC_SETOPTIONS:
405 if (get_user(new_options, uarg.i))
408 if (new_options & WDIOS_DISABLECARD) {
413 if (new_options & WDIOS_ENABLECARD) {
420 case WDIOC_KEEPALIVE:
424 case WDIOC_SETTIMEOUT:
425 if (get_user(new_timeout, uarg.i))
428 if (wdt_set_timeout(new_timeout))
434 case WDIOC_GETTIMEOUT:
435 return put_user(timeout, uarg.i);
443 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
446 if (code == SYS_DOWN || code == SYS_HALT)
451 static const struct file_operations wdt_fops = {
452 .owner = THIS_MODULE,
455 .unlocked_ioctl = wdt_ioctl,
457 .release = wdt_release,
460 static struct miscdevice wdt_miscdev = {
461 .minor = WATCHDOG_MINOR,
466 static struct notifier_block wdt_notifier = {
467 .notifier_call = wdt_notify_sys,
470 static int __init w83977f_wdt_init(void)
474 printk(KERN_INFO PFX DRIVER_VERSION);
477 * Check that the timeout value is within it's range;
478 * if not reset to the default
480 if (wdt_set_timeout(timeout)) {
481 wdt_set_timeout(DEFAULT_TIMEOUT);
483 "timeout value must be 15 <= timeout <= 7635, using %d\n",
487 if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
488 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
494 rc = register_reboot_notifier(&wdt_notifier);
497 "cannot register reboot notifier (err=%d)\n", rc);
501 rc = misc_register(&wdt_miscdev);
504 "cannot register miscdev on minor=%d (err=%d)\n",
505 wdt_miscdev.minor, rc);
510 "initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
511 timeout, nowayout, testmode);
516 unregister_reboot_notifier(&wdt_notifier);
518 release_region(IO_INDEX_PORT, 2);
523 static void __exit w83977f_wdt_exit(void)
526 misc_deregister(&wdt_miscdev);
527 unregister_reboot_notifier(&wdt_notifier);
528 release_region(IO_INDEX_PORT, 2);
531 module_init(w83977f_wdt_init);
532 module_exit(w83977f_wdt_exit);
534 MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
535 MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
536 MODULE_LICENSE("GPL");
537 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);