Merge branch 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
[linux-2.6-block.git] / drivers / watchdog / alim7101_wdt.c
CommitLineData
1da177e4
LT
1/*
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
27c766aa
JP
22#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
1da177e4
LT
24#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>
173d95bc
AC
36#include <linux/io.h>
37#include <linux/uaccess.h>
089ab079 38
1da177e4 39
1da177e4
LT
40#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 */
173d95bc
AC
61/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
62static int timeout = WATCHDOG_TIMEOUT;
1da177e4 63module_param(timeout, int, 0);
173d95bc
AC
64MODULE_PARM_DESC(timeout,
65 "Watchdog timeout in seconds. (1<=timeout<=3600, default="
66 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
1da177e4 67
173d95bc 68static int use_gpio; /* Use the pic (for a1d revision alim7101) */
1da177e4 69module_param(use_gpio, int, 0);
173d95bc
AC
70MODULE_PARM_DESC(use_gpio,
71 "Use the gpio watchdog (required by old cobalt boards).");
1da177e4
LT
72
73static void wdt_timer_ping(unsigned long);
82eb7c50 74static DEFINE_TIMER(timer, wdt_timer_ping, 0, 1);
1da177e4
LT
75static unsigned long next_heartbeat;
76static unsigned long wdt_is_open;
77static char wdt_expect_close;
78static struct pci_dev *alim7101_pmu;
79
86a1e189
WVS
80static bool nowayout = WATCHDOG_NOWAYOUT;
81module_param(nowayout, bool, 0);
173d95bc
AC
82MODULE_PARM_DESC(nowayout,
83 "Watchdog cannot be stopped once started (default="
84 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4
LT
85
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 */
173d95bc 95 char tmp;
1da177e4 96
173d95bc 97 if (time_before(jiffies, next_heartbeat)) {
1da177e4
LT
98 /* Ping the WDT (this is actually a disarm/arm sequence) */
99 pci_read_config_byte(alim7101_pmu, 0x92, &tmp);
173d95bc
AC
100 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));
1da177e4 104 if (use_gpio) {
173d95bc
AC
105 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);
1da177e4
LT
111 }
112 } else {
27c766aa 113 pr_warn("Heartbeat lost! Will not ping the watchdog\n");
1da177e4
LT
114 }
115 /* Re-set the timer interval */
82eb7c50 116 mod_timer(&timer, jiffies + WDT_INTERVAL);
1da177e4
LT
117}
118
119/*
120 * Utility routines
121 */
122
123static void wdt_change(int writeval)
124{
7944d3a5 125 char tmp;
1da177e4
LT
126
127 pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp);
128 if (writeval == WDT_ENABLE) {
173d95bc
AC
129 pci_write_config_byte(alim7101_pmu,
130 ALI_7101_WDT, (tmp | ALI_WDT_ARM));
1da177e4 131 if (use_gpio) {
173d95bc
AC
132 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);
1da177e4
LT
136 }
137
138 } else {
173d95bc
AC
139 pci_write_config_byte(alim7101_pmu,
140 ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
1da177e4 141 if (use_gpio) {
173d95bc
AC
142 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);
1da177e4
LT
146 }
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 */
82eb7c50 160 mod_timer(&timer, jiffies + WDT_INTERVAL);
1da177e4 161
27c766aa 162 pr_info("Watchdog timer is now enabled\n");
1da177e4
LT
163}
164
165static void wdt_turnoff(void)
166{
167 /* Stop the timer */
168 del_timer_sync(&timer);
169 wdt_change(WDT_DISABLE);
27c766aa 170 pr_info("Watchdog timer is now disabled...\n");
1da177e4
LT
171}
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
173d95bc
AC
183static ssize_t fop_write(struct file *file, const char __user *buf,
184 size_t count, loff_t *ppos)
1da177e4
LT
185{
186 /* See if we got the magic character 'V' and reload the timer */
173d95bc 187 if (count) {
1da177e4
LT
188 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;
7944d3a5 198 if (get_user(c, buf + ofs))
1da177e4
LT
199 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
173d95bc 210static int fop_open(struct inode *inode, struct file *file)
1da177e4
LT
211{
212 /* Just in case we're already talking to someone... */
173d95bc 213 if (test_and_set_bit(0, &wdt_is_open))
1da177e4
LT
214 return -EBUSY;
215 /* Good, fire up the show */
216 wdt_startup();
217 return nonseekable_open(inode, file);
218}
219
173d95bc 220static int fop_close(struct inode *inode, struct file *file)
1da177e4 221{
173d95bc 222 if (wdt_expect_close == 42)
1da177e4
LT
223 wdt_turnoff();
224 else {
225 /* wim: shouldn't there be a: del_timer(&timer); */
27c766aa 226 pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
1da177e4
LT
227 }
228 clear_bit(0, &wdt_is_open);
229 wdt_expect_close = 0;
230 return 0;
231}
232
173d95bc 233static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4
LT
234{
235 void __user *argp = (void __user *)arg;
236 int __user *p = argp;
42747d71 237 static const struct watchdog_info ident = {
173d95bc
AC
238 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
239 | WDIOF_MAGICCLOSE,
1da177e4
LT
240 .firmware_version = 1,
241 .identity = "ALiM7101",
242 };
243
173d95bc
AC
244 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);
173d95bc 250 case WDIOC_SETOPTIONS:
1da177e4 251 {
173d95bc 252 int new_options, retval = -EINVAL;
1da177e4 253
173d95bc
AC
254 if (get_user(new_options, p))
255 return -EFAULT;
256 if (new_options & WDIOS_DISABLECARD) {
257 wdt_turnoff();
258 retval = 0;
1da177e4 259 }
173d95bc
AC
260 if (new_options & WDIOS_ENABLECARD) {
261 wdt_startup();
262 retval = 0;
1da177e4 263 }
173d95bc
AC
264 return retval;
265 }
0c06090c
WVS
266 case WDIOC_KEEPALIVE:
267 wdt_keepalive();
268 return 0;
173d95bc
AC
269 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;
1da177e4
LT
286 }
287}
288
62322d25 289static const struct file_operations wdt_fops = {
173d95bc
AC
290 .owner = THIS_MODULE,
291 .llseek = no_llseek,
292 .write = fop_write,
293 .open = fop_open,
294 .release = fop_close,
295 .unlocked_ioctl = fop_ioctl,
1da177e4
LT
296};
297
298static struct miscdevice wdt_miscdev = {
173d95bc
AC
299 .minor = WATCHDOG_MINOR,
300 .name = "watchdog",
301 .fops = &wdt_fops,
1da177e4
LT
302};
303
304/*
305 * Notifier for system down
306 */
307
173d95bc
AC
308static int wdt_notify_sys(struct notifier_block *this,
309 unsigned long code, void *unused)
1da177e4 310{
173d95bc 311 if (code == SYS_DOWN || code == SYS_HALT)
1da177e4
LT
312 wdt_turnoff();
313
173d95bc 314 if (code == SYS_RESTART) {
1da177e4 315 /*
173d95bc
AC
316 * 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
1da177e4
LT
319 */
320 wdt_change(WDT_ENABLE);
27c766aa 321 pr_info("Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second\n");
1da177e4
LT
322 }
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
173d95bc 331static struct notifier_block wdt_notifier = {
1da177e4
LT
332 .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);
02be2ee9 341 pci_dev_put(alim7101_pmu);
1da177e4
LT
342}
343
344static int __init alim7101_wdt_init(void)
345{
346 int rc = -EBUSY;
347 struct pci_dev *ali1543_south;
348 char tmp;
349
27c766aa 350 pr_info("Steve Hill <steve@navaho.co.uk>\n");
02be2ee9
JS
351 alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
352 NULL);
1da177e4 353 if (!alim7101_pmu) {
27c766aa 354 pr_info("ALi M7101 PMU not present - WDT not set\n");
1da177e4
LT
355 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
02be2ee9
JS
361 ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
362 NULL);
1da177e4 363 if (!ali1543_south) {
27c766aa 364 pr_info("ALi 1543 South-Bridge not present - WDT not set\n");
02be2ee9 365 goto err_out;
1da177e4
LT
366 }
367 pci_read_config_byte(ali1543_south, 0x5e, &tmp);
02be2ee9 368 pci_dev_put(ali1543_south);
1da177e4
LT
369 if ((tmp & 0x1e) == 0x00) {
370 if (!use_gpio) {
27c766aa 371 pr_info("Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n");
02be2ee9 372 goto err_out;
173d95bc 373 }
1da177e4
LT
374 nowayout = 1;
375 } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
27c766aa 376 pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
02be2ee9 377 goto err_out;
1da177e4
LT
378 }
379
173d95bc
AC
380 if (timeout < 1 || timeout > 3600) {
381 /* arbitrary upper limit */
1da177e4 382 timeout = WATCHDOG_TIMEOUT;
27c766aa
JP
383 pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
384 timeout);
1da177e4
LT
385 }
386
c6cb13ae 387 rc = register_reboot_notifier(&wdt_notifier);
1da177e4 388 if (rc) {
27c766aa 389 pr_err("cannot register reboot notifier (err=%d)\n", rc);
1da177e4
LT
390 goto err_out;
391 }
392
c6cb13ae 393 rc = misc_register(&wdt_miscdev);
1da177e4 394 if (rc) {
27c766aa
JP
395 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
396 wdt_miscdev.minor, rc);
c6cb13ae 397 goto err_out_reboot;
1da177e4
LT
398 }
399
173d95bc 400 if (nowayout)
1da177e4 401 __module_get(THIS_MODULE);
1da177e4 402
27c766aa 403 pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
1da177e4
LT
404 timeout, nowayout);
405 return 0;
406
c6cb13ae
WVS
407err_out_reboot:
408 unregister_reboot_notifier(&wdt_notifier);
1da177e4 409err_out:
02be2ee9 410 pci_dev_put(alim7101_pmu);
1da177e4
LT
411 return rc;
412}
413
414module_init(alim7101_wdt_init);
415module_exit(alim7101_wdt_unload);
416
4562f539 417static DEFINE_PCI_DEVICE_TABLE(alim7101_pci_tbl) __used = {
29d73aab
JS
418 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
419 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
5cacb9f8
BC
420 { }
421};
422
423MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);
424
1da177e4
LT
425MODULE_AUTHOR("Steve Hill");
426MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
427MODULE_LICENSE("GPL");
428MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);