blob: a045ef869439345dd3ab9d27794721fa2c09d443 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * ALi M7101 PMU Computer Watchdog Timer driver
3 *
4 * Based on w83877f_wdt.c by Scott Jennings <linuxdrivers@oro.net>
5 * and the Cobalt kernel WDT timer driver by Tim Hockin
6 * <thockin@cobaltnet.com>
7 *
8 * (c)2002 Steve Hill <steve@navaho.co.uk>
9 *
10 * This WDT driver is different from most other Linux WDT
11 * drivers in that the driver will ping the watchdog by itself,
12 * because this particular WDT has a very short timeout (1.6
13 * seconds) and it would be insane to count on any userspace
14 * daemon always getting scheduled within that time frame.
15 *
16 * Additions:
17 * Aug 23, 2004 - Added use_gpio module parameter for use on revision a1d PMUs
18 * found on very old cobalt hardware.
19 * -- Mike Waychison <michael.waychison@sun.com>
20 */
21
22#include <linux/module.h>
23#include <linux/moduleparam.h>
24#include <linux/types.h>
25#include <linux/timer.h>
26#include <linux/miscdevice.h>
27#include <linux/watchdog.h>
28#include <linux/ioport.h>
29#include <linux/notifier.h>
30#include <linux/reboot.h>
31#include <linux/init.h>
32#include <linux/fs.h>
33#include <linux/pci.h>
Alan Cox173d95b2008-05-19 14:04:57 +010034#include <linux/io.h>
35#include <linux/uaccess.h>
Wim Van Sebroeck089ab072008-07-15 11:46:11 +000036
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <asm/system.h>
38
39#define OUR_NAME "alim7101_wdt"
40#define PFX OUR_NAME ": "
41
42#define WDT_ENABLE 0x9C
43#define WDT_DISABLE 0x8C
44
45#define ALI_7101_WDT 0x92
46#define ALI_7101_GPIO 0x7D
47#define ALI_7101_GPIO_O 0x7E
48#define ALI_WDT_ARM 0x01
49
50/*
51 * We're going to use a 1 second timeout.
52 * If we reset the watchdog every ~250ms we should be safe. */
53
54#define WDT_INTERVAL (HZ/4+1)
55
56/*
57 * We must not require too good response from the userspace daemon.
58 * Here we require the userspace daemon to send us a heartbeat
59 * char to /dev/watchdog every 30 seconds.
60 */
61
62#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
Alan Cox173d95b2008-05-19 14:04:57 +010063/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
64static int timeout = WATCHDOG_TIMEOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065module_param(timeout, int, 0);
Alan Cox173d95b2008-05-19 14:04:57 +010066MODULE_PARM_DESC(timeout,
67 "Watchdog timeout in seconds. (1<=timeout<=3600, default="
68 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
Alan Cox173d95b2008-05-19 14:04:57 +010070static int use_gpio; /* Use the pic (for a1d revision alim7101) */
Linus Torvalds1da177e2005-04-16 15:20:36 -070071module_param(use_gpio, int, 0);
Alan Cox173d95b2008-05-19 14:04:57 +010072MODULE_PARM_DESC(use_gpio,
73 "Use the gpio watchdog (required by old cobalt boards).");
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75static void wdt_timer_ping(unsigned long);
Jiri Slaby82eb7c52007-02-08 18:39:36 +010076static DEFINE_TIMER(timer, wdt_timer_ping, 0, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077static unsigned long next_heartbeat;
78static unsigned long wdt_is_open;
79static char wdt_expect_close;
80static struct pci_dev *alim7101_pmu;
81
Andrey Panin4bfdf372005-07-27 11:43:58 -070082static int nowayout = WATCHDOG_NOWAYOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -070083module_param(nowayout, int, 0);
Alan Cox173d95b2008-05-19 14:04:57 +010084MODULE_PARM_DESC(nowayout,
85 "Watchdog cannot be stopped once started (default="
86 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88/*
89 * Whack the dog
90 */
91
92static void wdt_timer_ping(unsigned long data)
93{
94 /* If we got a heartbeat pulse within the WDT_US_INTERVAL
95 * we agree to ping the WDT
96 */
Alan Cox173d95b2008-05-19 14:04:57 +010097 char tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
Alan Cox173d95b2008-05-19 14:04:57 +010099 if (time_before(jiffies, next_heartbeat)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 /* Ping the WDT (this is actually a disarm/arm sequence) */
101 pci_read_config_byte(alim7101_pmu, 0x92, &tmp);
Alan Cox173d95b2008-05-19 14:04:57 +0100102 pci_write_config_byte(alim7101_pmu,
103 ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
104 pci_write_config_byte(alim7101_pmu,
105 ALI_7101_WDT, (tmp | ALI_WDT_ARM));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 if (use_gpio) {
Alan Cox173d95b2008-05-19 14:04:57 +0100107 pci_read_config_byte(alim7101_pmu,
108 ALI_7101_GPIO_O, &tmp);
109 pci_write_config_byte(alim7101_pmu,
110 ALI_7101_GPIO_O, tmp | 0x20);
111 pci_write_config_byte(alim7101_pmu,
112 ALI_7101_GPIO_O, tmp & ~0x20);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 }
114 } else {
Alan Cox173d95b2008-05-19 14:04:57 +0100115 printk(KERN_WARNING PFX
116 "Heartbeat lost! Will not ping the watchdog\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 }
118 /* Re-set the timer interval */
Jiri Slaby82eb7c52007-02-08 18:39:36 +0100119 mod_timer(&timer, jiffies + WDT_INTERVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120}
121
122/*
123 * Utility routines
124 */
125
126static void wdt_change(int writeval)
127{
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000128 char tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129
130 pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp);
131 if (writeval == WDT_ENABLE) {
Alan Cox173d95b2008-05-19 14:04:57 +0100132 pci_write_config_byte(alim7101_pmu,
133 ALI_7101_WDT, (tmp | ALI_WDT_ARM));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 if (use_gpio) {
Alan Cox173d95b2008-05-19 14:04:57 +0100135 pci_read_config_byte(alim7101_pmu,
136 ALI_7101_GPIO_O, &tmp);
137 pci_write_config_byte(alim7101_pmu,
138 ALI_7101_GPIO_O, tmp & ~0x20);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 }
140
141 } else {
Alan Cox173d95b2008-05-19 14:04:57 +0100142 pci_write_config_byte(alim7101_pmu,
143 ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 if (use_gpio) {
Alan Cox173d95b2008-05-19 14:04:57 +0100145 pci_read_config_byte(alim7101_pmu,
146 ALI_7101_GPIO_O, &tmp);
147 pci_write_config_byte(alim7101_pmu,
148 ALI_7101_GPIO_O, tmp | 0x20);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 }
150 }
151}
152
153static void wdt_startup(void)
154{
155 next_heartbeat = jiffies + (timeout * HZ);
156
157 /* We must enable before we kick off the timer in case the timer
158 occurs as we ping it */
159
160 wdt_change(WDT_ENABLE);
161
162 /* Start the timer */
Jiri Slaby82eb7c52007-02-08 18:39:36 +0100163 mod_timer(&timer, jiffies + WDT_INTERVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
165 printk(KERN_INFO PFX "Watchdog timer is now enabled.\n");
166}
167
168static void wdt_turnoff(void)
169{
170 /* Stop the timer */
171 del_timer_sync(&timer);
172 wdt_change(WDT_DISABLE);
173 printk(KERN_INFO PFX "Watchdog timer is now disabled...\n");
174}
175
176static void wdt_keepalive(void)
177{
178 /* user land ping */
179 next_heartbeat = jiffies + (timeout * HZ);
180}
181
182/*
183 * /dev/watchdog handling
184 */
185
Alan Cox173d95b2008-05-19 14:04:57 +0100186static ssize_t fop_write(struct file *file, const char __user *buf,
187 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188{
189 /* See if we got the magic character 'V' and reload the timer */
Alan Cox173d95b2008-05-19 14:04:57 +0100190 if (count) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 if (!nowayout) {
192 size_t ofs;
193
194 /* note: just in case someone wrote the magic character
195 * five months ago... */
196 wdt_expect_close = 0;
197
198 /* now scan */
199 for (ofs = 0; ofs != count; ofs++) {
200 char c;
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000201 if (get_user(c, buf + ofs))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 return -EFAULT;
203 if (c == 'V')
204 wdt_expect_close = 42;
205 }
206 }
207 /* someone wrote to us, we should restart timer */
208 wdt_keepalive();
209 }
210 return count;
211}
212
Alan Cox173d95b2008-05-19 14:04:57 +0100213static int fop_open(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214{
215 /* Just in case we're already talking to someone... */
Alan Cox173d95b2008-05-19 14:04:57 +0100216 if (test_and_set_bit(0, &wdt_is_open))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 return -EBUSY;
218 /* Good, fire up the show */
219 wdt_startup();
220 return nonseekable_open(inode, file);
221}
222
Alan Cox173d95b2008-05-19 14:04:57 +0100223static int fop_close(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224{
Alan Cox173d95b2008-05-19 14:04:57 +0100225 if (wdt_expect_close == 42)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 wdt_turnoff();
227 else {
228 /* wim: shouldn't there be a: del_timer(&timer); */
Alan Cox173d95b2008-05-19 14:04:57 +0100229 printk(KERN_CRIT PFX
230 "device file closed unexpectedly. Will not stop the WDT!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 }
232 clear_bit(0, &wdt_is_open);
233 wdt_expect_close = 0;
234 return 0;
235}
236
Alan Cox173d95b2008-05-19 14:04:57 +0100237static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238{
239 void __user *argp = (void __user *)arg;
240 int __user *p = argp;
Alan Cox173d95b2008-05-19 14:04:57 +0100241 static struct watchdog_info ident = {
242 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
243 | WDIOF_MAGICCLOSE,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 .firmware_version = 1,
245 .identity = "ALiM7101",
246 };
247
Alan Cox173d95b2008-05-19 14:04:57 +0100248 switch (cmd) {
249 case WDIOC_GETSUPPORT:
250 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
251 case WDIOC_GETSTATUS:
252 case WDIOC_GETBOOTSTATUS:
253 return put_user(0, p);
Alan Cox173d95b2008-05-19 14:04:57 +0100254 case WDIOC_SETOPTIONS:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 {
Alan Cox173d95b2008-05-19 14:04:57 +0100256 int new_options, retval = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
Alan Cox173d95b2008-05-19 14:04:57 +0100258 if (get_user(new_options, p))
259 return -EFAULT;
260 if (new_options & WDIOS_DISABLECARD) {
261 wdt_turnoff();
262 retval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 }
Alan Cox173d95b2008-05-19 14:04:57 +0100264 if (new_options & WDIOS_ENABLECARD) {
265 wdt_startup();
266 retval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 }
Alan Cox173d95b2008-05-19 14:04:57 +0100268 return retval;
269 }
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000270 case WDIOC_KEEPALIVE:
271 wdt_keepalive();
272 return 0;
Alan Cox173d95b2008-05-19 14:04:57 +0100273 case WDIOC_SETTIMEOUT:
274 {
275 int new_timeout;
276
277 if (get_user(new_timeout, p))
278 return -EFAULT;
279 /* arbitrary upper limit */
280 if (new_timeout < 1 || new_timeout > 3600)
281 return -EINVAL;
282 timeout = new_timeout;
283 wdt_keepalive();
284 /* Fall through */
285 }
286 case WDIOC_GETTIMEOUT:
287 return put_user(timeout, p);
288 default:
289 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 }
291}
292
Arjan van de Ven62322d22006-07-03 00:24:21 -0700293static const struct file_operations wdt_fops = {
Alan Cox173d95b2008-05-19 14:04:57 +0100294 .owner = THIS_MODULE,
295 .llseek = no_llseek,
296 .write = fop_write,
297 .open = fop_open,
298 .release = fop_close,
299 .unlocked_ioctl = fop_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300};
301
302static struct miscdevice wdt_miscdev = {
Alan Cox173d95b2008-05-19 14:04:57 +0100303 .minor = WATCHDOG_MINOR,
304 .name = "watchdog",
305 .fops = &wdt_fops,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306};
307
308/*
309 * Notifier for system down
310 */
311
Alan Cox173d95b2008-05-19 14:04:57 +0100312static int wdt_notify_sys(struct notifier_block *this,
313 unsigned long code, void *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314{
Alan Cox173d95b2008-05-19 14:04:57 +0100315 if (code == SYS_DOWN || code == SYS_HALT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 wdt_turnoff();
317
Alan Cox173d95b2008-05-19 14:04:57 +0100318 if (code == SYS_RESTART) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 /*
Alan Cox173d95b2008-05-19 14:04:57 +0100320 * Cobalt devices have no way of rebooting themselves other
321 * than getting the watchdog to pull reset, so we restart the
322 * watchdog on reboot with no heartbeat
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 */
324 wdt_change(WDT_ENABLE);
325 printk(KERN_INFO PFX "Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second.\n");
326 }
327 return NOTIFY_DONE;
328}
329
330/*
331 * The WDT needs to learn about soft shutdowns in order to
332 * turn the timebomb registers off.
333 */
334
Alan Cox173d95b2008-05-19 14:04:57 +0100335static struct notifier_block wdt_notifier = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 .notifier_call = wdt_notify_sys,
337};
338
339static void __exit alim7101_wdt_unload(void)
340{
341 wdt_turnoff();
342 /* Deregister */
343 misc_deregister(&wdt_miscdev);
344 unregister_reboot_notifier(&wdt_notifier);
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159345 pci_dev_put(alim7101_pmu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346}
347
348static int __init alim7101_wdt_init(void)
349{
350 int rc = -EBUSY;
351 struct pci_dev *ali1543_south;
352 char tmp;
353
354 printk(KERN_INFO PFX "Steve Hill <steve@navaho.co.uk>.\n");
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159355 alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
356 NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 if (!alim7101_pmu) {
358 printk(KERN_INFO PFX "ALi M7101 PMU not present - WDT not set\n");
359 return -EBUSY;
360 }
361
362 /* Set the WDT in the PMU to 1 second */
363 pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02);
364
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159365 ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
366 NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 if (!ali1543_south) {
Alan Cox173d95b2008-05-19 14:04:57 +0100368 printk(KERN_INFO PFX
369 "ALi 1543 South-Bridge not present - WDT not set\n");
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159370 goto err_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 }
372 pci_read_config_byte(ali1543_south, 0x5e, &tmp);
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159373 pci_dev_put(ali1543_south);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 if ((tmp & 0x1e) == 0x00) {
375 if (!use_gpio) {
376 printk(KERN_INFO PFX "Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n");
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159377 goto err_out;
Alan Cox173d95b2008-05-19 14:04:57 +0100378 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 nowayout = 1;
380 } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
381 printk(KERN_INFO PFX "ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159382 goto err_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 }
384
Alan Cox173d95b2008-05-19 14:04:57 +0100385 if (timeout < 1 || timeout > 3600) {
386 /* arbitrary upper limit */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 timeout = WATCHDOG_TIMEOUT;
Alan Cox173d95b2008-05-19 14:04:57 +0100388 printk(KERN_INFO PFX
389 "timeout value must be 1 <= x <= 3600, using %d\n",
390 timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 }
392
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 rc = register_reboot_notifier(&wdt_notifier);
394 if (rc) {
Alan Cox173d95b2008-05-19 14:04:57 +0100395 printk(KERN_ERR PFX
396 "cannot register reboot notifier (err=%d)\n", rc);
Wim Van Sebroeckc6cb13a2007-12-26 20:32:51 +0000397 goto err_out;
398 }
399
400 rc = misc_register(&wdt_miscdev);
401 if (rc) {
402 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
403 wdt_miscdev.minor, rc);
404 goto err_out_reboot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 }
406
Alan Cox173d95b2008-05-19 14:04:57 +0100407 if (nowayout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 __module_get(THIS_MODULE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409
410 printk(KERN_INFO PFX "WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
411 timeout, nowayout);
412 return 0;
413
Wim Van Sebroeckc6cb13a2007-12-26 20:32:51 +0000414err_out_reboot:
415 unregister_reboot_notifier(&wdt_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416err_out:
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159417 pci_dev_put(alim7101_pmu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 return rc;
419}
420
421module_init(alim7101_wdt_init);
422module_exit(alim7101_wdt_unload);
423
Ben Collins5cacb9f2006-10-18 08:24:30 -0400424static struct pci_device_id alim7101_pci_tbl[] __devinitdata = {
Jiri Slaby29d73aa2007-02-12 00:51:48 -0800425 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
426 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
Ben Collins5cacb9f2006-10-18 08:24:30 -0400427 { }
428};
429
430MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);
431
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432MODULE_AUTHOR("Steve Hill");
433MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
434MODULE_LICENSE("GPL");
435MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);