blob: 5eee55012e3375915b769e2bbcf05da9adbeff60 [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
Joe Perches27c766a2012-02-15 15:06:19 -080022#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/module.h>
25#include <linux/moduleparam.h>
26#include <linux/types.h>
27#include <linux/timer.h>
28#include <linux/miscdevice.h>
29#include <linux/watchdog.h>
30#include <linux/ioport.h>
31#include <linux/notifier.h>
32#include <linux/reboot.h>
33#include <linux/init.h>
34#include <linux/fs.h>
35#include <linux/pci.h>
Alan Cox173d95b2008-05-19 14:04:57 +010036#include <linux/io.h>
37#include <linux/uaccess.h>
Wim Van Sebroeck089ab072008-07-15 11:46:11 +000038
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Linus Torvalds1da177e2005-04-16 15:20:36 -070040#define WDT_ENABLE 0x9C
41#define WDT_DISABLE 0x8C
42
43#define ALI_7101_WDT 0x92
44#define ALI_7101_GPIO 0x7D
45#define ALI_7101_GPIO_O 0x7E
46#define ALI_WDT_ARM 0x01
47
48/*
49 * We're going to use a 1 second timeout.
50 * If we reset the watchdog every ~250ms we should be safe. */
51
52#define WDT_INTERVAL (HZ/4+1)
53
54/*
55 * We must not require too good response from the userspace daemon.
56 * Here we require the userspace daemon to send us a heartbeat
57 * char to /dev/watchdog every 30 seconds.
58 */
59
60#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
Alan Cox173d95b2008-05-19 14:04:57 +010061/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
62static int timeout = WATCHDOG_TIMEOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063module_param(timeout, int, 0);
Alan Cox173d95b2008-05-19 14:04:57 +010064MODULE_PARM_DESC(timeout,
65 "Watchdog timeout in seconds. (1<=timeout<=3600, default="
66 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
Alan Cox173d95b2008-05-19 14:04:57 +010068static int use_gpio; /* Use the pic (for a1d revision alim7101) */
Linus Torvalds1da177e2005-04-16 15:20:36 -070069module_param(use_gpio, int, 0);
Alan Cox173d95b2008-05-19 14:04:57 +010070MODULE_PARM_DESC(use_gpio,
71 "Use the gpio watchdog (required by old cobalt boards).");
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73static void wdt_timer_ping(unsigned long);
Jiri Slaby82eb7c52007-02-08 18:39:36 +010074static DEFINE_TIMER(timer, wdt_timer_ping, 0, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075static unsigned long next_heartbeat;
76static unsigned long wdt_is_open;
77static char wdt_expect_close;
78static struct pci_dev *alim7101_pmu;
79
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010080static bool nowayout = WATCHDOG_NOWAYOUT;
81module_param(nowayout, bool, 0);
Alan Cox173d95b2008-05-19 14:04:57 +010082MODULE_PARM_DESC(nowayout,
83 "Watchdog cannot be stopped once started (default="
84 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -070085
86/*
87 * Whack the dog
88 */
89
90static void wdt_timer_ping(unsigned long data)
91{
92 /* If we got a heartbeat pulse within the WDT_US_INTERVAL
93 * we agree to ping the WDT
94 */
Alan Cox173d95b2008-05-19 14:04:57 +010095 char tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
Alan Cox173d95b2008-05-19 14:04:57 +010097 if (time_before(jiffies, next_heartbeat)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 /* Ping the WDT (this is actually a disarm/arm sequence) */
99 pci_read_config_byte(alim7101_pmu, 0x92, &tmp);
Alan Cox173d95b2008-05-19 14:04:57 +0100100 pci_write_config_byte(alim7101_pmu,
101 ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
102 pci_write_config_byte(alim7101_pmu,
103 ALI_7101_WDT, (tmp | ALI_WDT_ARM));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 if (use_gpio) {
Alan Cox173d95b2008-05-19 14:04:57 +0100105 pci_read_config_byte(alim7101_pmu,
106 ALI_7101_GPIO_O, &tmp);
107 pci_write_config_byte(alim7101_pmu,
108 ALI_7101_GPIO_O, tmp | 0x20);
109 pci_write_config_byte(alim7101_pmu,
110 ALI_7101_GPIO_O, tmp & ~0x20);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 }
112 } else {
Joe Perches27c766a2012-02-15 15:06:19 -0800113 pr_warn("Heartbeat lost! Will not ping the watchdog\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 }
115 /* Re-set the timer interval */
Jiri Slaby82eb7c52007-02-08 18:39:36 +0100116 mod_timer(&timer, jiffies + WDT_INTERVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117}
118
119/*
120 * Utility routines
121 */
122
123static void wdt_change(int writeval)
124{
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000125 char tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
127 pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp);
128 if (writeval == WDT_ENABLE) {
Alan Cox173d95b2008-05-19 14:04:57 +0100129 pci_write_config_byte(alim7101_pmu,
130 ALI_7101_WDT, (tmp | ALI_WDT_ARM));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 if (use_gpio) {
Alan Cox173d95b2008-05-19 14:04:57 +0100132 pci_read_config_byte(alim7101_pmu,
133 ALI_7101_GPIO_O, &tmp);
134 pci_write_config_byte(alim7101_pmu,
135 ALI_7101_GPIO_O, tmp & ~0x20);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 }
137
138 } else {
Alan Cox173d95b2008-05-19 14:04:57 +0100139 pci_write_config_byte(alim7101_pmu,
140 ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 if (use_gpio) {
Alan Cox173d95b2008-05-19 14:04:57 +0100142 pci_read_config_byte(alim7101_pmu,
143 ALI_7101_GPIO_O, &tmp);
144 pci_write_config_byte(alim7101_pmu,
145 ALI_7101_GPIO_O, tmp | 0x20);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 }
147 }
148}
149
150static void wdt_startup(void)
151{
152 next_heartbeat = jiffies + (timeout * HZ);
153
154 /* We must enable before we kick off the timer in case the timer
155 occurs as we ping it */
156
157 wdt_change(WDT_ENABLE);
158
159 /* Start the timer */
Jiri Slaby82eb7c52007-02-08 18:39:36 +0100160 mod_timer(&timer, jiffies + WDT_INTERVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
Joe Perches27c766a2012-02-15 15:06:19 -0800162 pr_info("Watchdog timer is now enabled\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163}
164
165static void wdt_turnoff(void)
166{
167 /* Stop the timer */
168 del_timer_sync(&timer);
169 wdt_change(WDT_DISABLE);
Joe Perches27c766a2012-02-15 15:06:19 -0800170 pr_info("Watchdog timer is now disabled...\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171}
172
173static void wdt_keepalive(void)
174{
175 /* user land ping */
176 next_heartbeat = jiffies + (timeout * HZ);
177}
178
179/*
180 * /dev/watchdog handling
181 */
182
Alan Cox173d95b2008-05-19 14:04:57 +0100183static ssize_t fop_write(struct file *file, const char __user *buf,
184 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185{
186 /* See if we got the magic character 'V' and reload the timer */
Alan Cox173d95b2008-05-19 14:04:57 +0100187 if (count) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 if (!nowayout) {
189 size_t ofs;
190
191 /* note: just in case someone wrote the magic character
192 * five months ago... */
193 wdt_expect_close = 0;
194
195 /* now scan */
196 for (ofs = 0; ofs != count; ofs++) {
197 char c;
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000198 if (get_user(c, buf + ofs))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 return -EFAULT;
200 if (c == 'V')
201 wdt_expect_close = 42;
202 }
203 }
204 /* someone wrote to us, we should restart timer */
205 wdt_keepalive();
206 }
207 return count;
208}
209
Alan Cox173d95b2008-05-19 14:04:57 +0100210static int fop_open(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211{
212 /* Just in case we're already talking to someone... */
Alan Cox173d95b2008-05-19 14:04:57 +0100213 if (test_and_set_bit(0, &wdt_is_open))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 return -EBUSY;
215 /* Good, fire up the show */
216 wdt_startup();
217 return nonseekable_open(inode, file);
218}
219
Alan Cox173d95b2008-05-19 14:04:57 +0100220static int fop_close(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221{
Alan Cox173d95b2008-05-19 14:04:57 +0100222 if (wdt_expect_close == 42)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 wdt_turnoff();
224 else {
225 /* wim: shouldn't there be a: del_timer(&timer); */
Joe Perches27c766a2012-02-15 15:06:19 -0800226 pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 }
228 clear_bit(0, &wdt_is_open);
229 wdt_expect_close = 0;
230 return 0;
231}
232
Alan Cox173d95b2008-05-19 14:04:57 +0100233static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234{
235 void __user *argp = (void __user *)arg;
236 int __user *p = argp;
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000237 static const struct watchdog_info ident = {
Alan Cox173d95b2008-05-19 14:04:57 +0100238 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
239 | WDIOF_MAGICCLOSE,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 .firmware_version = 1,
241 .identity = "ALiM7101",
242 };
243
Alan Cox173d95b2008-05-19 14:04:57 +0100244 switch (cmd) {
245 case WDIOC_GETSUPPORT:
246 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
247 case WDIOC_GETSTATUS:
248 case WDIOC_GETBOOTSTATUS:
249 return put_user(0, p);
Alan Cox173d95b2008-05-19 14:04:57 +0100250 case WDIOC_SETOPTIONS:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 {
Alan Cox173d95b2008-05-19 14:04:57 +0100252 int new_options, retval = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253
Alan Cox173d95b2008-05-19 14:04:57 +0100254 if (get_user(new_options, p))
255 return -EFAULT;
256 if (new_options & WDIOS_DISABLECARD) {
257 wdt_turnoff();
258 retval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 }
Alan Cox173d95b2008-05-19 14:04:57 +0100260 if (new_options & WDIOS_ENABLECARD) {
261 wdt_startup();
262 retval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 }
Alan Cox173d95b2008-05-19 14:04:57 +0100264 return retval;
265 }
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000266 case WDIOC_KEEPALIVE:
267 wdt_keepalive();
268 return 0;
Alan Cox173d95b2008-05-19 14:04:57 +0100269 case WDIOC_SETTIMEOUT:
270 {
271 int new_timeout;
272
273 if (get_user(new_timeout, p))
274 return -EFAULT;
275 /* arbitrary upper limit */
276 if (new_timeout < 1 || new_timeout > 3600)
277 return -EINVAL;
278 timeout = new_timeout;
279 wdt_keepalive();
280 /* Fall through */
281 }
282 case WDIOC_GETTIMEOUT:
283 return put_user(timeout, p);
284 default:
285 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 }
287}
288
Arjan van de Ven62322d22006-07-03 00:24:21 -0700289static const struct file_operations wdt_fops = {
Alan Cox173d95b2008-05-19 14:04:57 +0100290 .owner = THIS_MODULE,
291 .llseek = no_llseek,
292 .write = fop_write,
293 .open = fop_open,
294 .release = fop_close,
295 .unlocked_ioctl = fop_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296};
297
298static struct miscdevice wdt_miscdev = {
Alan Cox173d95b2008-05-19 14:04:57 +0100299 .minor = WATCHDOG_MINOR,
300 .name = "watchdog",
301 .fops = &wdt_fops,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302};
303
304/*
305 * Notifier for system down
306 */
307
Alan Cox173d95b2008-05-19 14:04:57 +0100308static int wdt_notify_sys(struct notifier_block *this,
309 unsigned long code, void *unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310{
Alan Cox173d95b2008-05-19 14:04:57 +0100311 if (code == SYS_DOWN || code == SYS_HALT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 wdt_turnoff();
313
Alan Cox173d95b2008-05-19 14:04:57 +0100314 if (code == SYS_RESTART) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 /*
Alan Cox173d95b2008-05-19 14:04:57 +0100316 * Cobalt devices have no way of rebooting themselves other
317 * than getting the watchdog to pull reset, so we restart the
318 * watchdog on reboot with no heartbeat
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 */
320 wdt_change(WDT_ENABLE);
Joe Perches27c766a2012-02-15 15:06:19 -0800321 pr_info("Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 }
323 return NOTIFY_DONE;
324}
325
326/*
327 * The WDT needs to learn about soft shutdowns in order to
328 * turn the timebomb registers off.
329 */
330
Alan Cox173d95b2008-05-19 14:04:57 +0100331static struct notifier_block wdt_notifier = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 .notifier_call = wdt_notify_sys,
333};
334
335static void __exit alim7101_wdt_unload(void)
336{
337 wdt_turnoff();
338 /* Deregister */
339 misc_deregister(&wdt_miscdev);
340 unregister_reboot_notifier(&wdt_notifier);
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159341 pci_dev_put(alim7101_pmu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342}
343
344static int __init alim7101_wdt_init(void)
345{
346 int rc = -EBUSY;
347 struct pci_dev *ali1543_south;
348 char tmp;
349
Joe Perches27c766a2012-02-15 15:06:19 -0800350 pr_info("Steve Hill <steve@navaho.co.uk>\n");
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159351 alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
352 NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 if (!alim7101_pmu) {
Joe Perches27c766a2012-02-15 15:06:19 -0800354 pr_info("ALi M7101 PMU not present - WDT not set\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 return -EBUSY;
356 }
357
358 /* Set the WDT in the PMU to 1 second */
359 pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02);
360
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159361 ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
362 NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 if (!ali1543_south) {
Joe Perches27c766a2012-02-15 15:06:19 -0800364 pr_info("ALi 1543 South-Bridge not present - WDT not set\n");
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159365 goto err_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 }
367 pci_read_config_byte(ali1543_south, 0x5e, &tmp);
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159368 pci_dev_put(ali1543_south);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 if ((tmp & 0x1e) == 0x00) {
370 if (!use_gpio) {
Joe Perches27c766a2012-02-15 15:06:19 -0800371 pr_info("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 +0159372 goto err_out;
Alan Cox173d95b2008-05-19 14:04:57 +0100373 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 nowayout = 1;
375 } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
Joe Perches27c766a2012-02-15 15:06:19 -0800376 pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159377 goto err_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 }
379
Alan Cox173d95b2008-05-19 14:04:57 +0100380 if (timeout < 1 || timeout > 3600) {
381 /* arbitrary upper limit */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 timeout = WATCHDOG_TIMEOUT;
Joe Perches27c766a2012-02-15 15:06:19 -0800383 pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
384 timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 }
386
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 rc = register_reboot_notifier(&wdt_notifier);
388 if (rc) {
Joe Perches27c766a2012-02-15 15:06:19 -0800389 pr_err("cannot register reboot notifier (err=%d)\n", rc);
Wim Van Sebroeckc6cb13a2007-12-26 20:32:51 +0000390 goto err_out;
391 }
392
393 rc = misc_register(&wdt_miscdev);
394 if (rc) {
Joe Perches27c766a2012-02-15 15:06:19 -0800395 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
396 wdt_miscdev.minor, rc);
Wim Van Sebroeckc6cb13a2007-12-26 20:32:51 +0000397 goto err_out_reboot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 }
399
Alan Cox173d95b2008-05-19 14:04:57 +0100400 if (nowayout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 __module_get(THIS_MODULE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402
Joe Perches27c766a2012-02-15 15:06:19 -0800403 pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 timeout, nowayout);
405 return 0;
406
Wim Van Sebroeckc6cb13a2007-12-26 20:32:51 +0000407err_out_reboot:
408 unregister_reboot_notifier(&wdt_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409err_out:
Jiri Slaby02be2ee2006-07-18 18:29:00 +0159410 pci_dev_put(alim7101_pmu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 return rc;
412}
413
414module_init(alim7101_wdt_init);
415module_exit(alim7101_wdt_unload);
416
Wim Van Sebroeck4562f532011-02-21 12:16:44 +0000417static DEFINE_PCI_DEVICE_TABLE(alim7101_pci_tbl) __used = {
Jiri Slaby29d73aa2007-02-12 00:51:48 -0800418 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
419 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
Ben Collins5cacb9f2006-10-18 08:24:30 -0400420 { }
421};
422
423MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);
424
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425MODULE_AUTHOR("Steve Hill");
426MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
427MODULE_LICENSE("GPL");
428MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);