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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
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>
34#include <linux/io.h>
35#include <linux/uaccess.h>
36
37#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 */
63/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
64static int timeout = WATCHDOG_TIMEOUT;
65module_param(timeout, int, 0);
66MODULE_PARM_DESC(timeout,
67 "Watchdog timeout in seconds. (1<=timeout<=3600, default="
68 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
69
70static int use_gpio; /* Use the pic (for a1d revision alim7101) */
71module_param(use_gpio, int, 0);
72MODULE_PARM_DESC(use_gpio,
73 "Use the gpio watchdog (required by old cobalt boards).");
74
75static void wdt_timer_ping(unsigned long);
76static DEFINE_TIMER(timer, wdt_timer_ping, 0, 1);
77static unsigned long next_heartbeat;
78static unsigned long wdt_is_open;
79static char wdt_expect_close;
80static struct pci_dev *alim7101_pmu;
81
82static int nowayout = WATCHDOG_NOWAYOUT;
83module_param(nowayout, int, 0);
84MODULE_PARM_DESC(nowayout,
85 "Watchdog cannot be stopped once started (default="
86 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
87
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 */
97 char tmp;
98
99 if (time_before(jiffies, next_heartbeat)) {
100 /* Ping the WDT (this is actually a disarm/arm sequence) */
101 pci_read_config_byte(alim7101_pmu, 0x92, &tmp);
102 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));
106 if (use_gpio) {
107 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);
113 }
114 } else {
115 printk(KERN_WARNING PFX
116 "Heartbeat lost! Will not ping the watchdog\n");
117 }
118 /* Re-set the timer interval */
119 mod_timer(&timer, jiffies + WDT_INTERVAL);
120}
121
122/*
123 * Utility routines
124 */
125
126static void wdt_change(int writeval)
127{
128 char tmp;
129
130 pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp);
131 if (writeval == WDT_ENABLE) {
132 pci_write_config_byte(alim7101_pmu,
133 ALI_7101_WDT, (tmp | ALI_WDT_ARM));
134 if (use_gpio) {
135 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);
139 }
140
141 } else {
142 pci_write_config_byte(alim7101_pmu,
143 ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
144 if (use_gpio) {
145 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);
149 }
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 */
163 mod_timer(&timer, jiffies + WDT_INTERVAL);
164
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
186static ssize_t fop_write(struct file *file, const char __user *buf,
187 size_t count, loff_t *ppos)
188{
189 /* See if we got the magic character 'V' and reload the timer */
190 if (count) {
191 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;
201 if (get_user(c, buf + ofs))
202 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
213static int fop_open(struct inode *inode, struct file *file)
214{
215 /* Just in case we're already talking to someone... */
216 if (test_and_set_bit(0, &wdt_is_open))
217 return -EBUSY;
218 /* Good, fire up the show */
219 wdt_startup();
220 return nonseekable_open(inode, file);
221}
222
223static int fop_close(struct inode *inode, struct file *file)
224{
225 if (wdt_expect_close == 42)
226 wdt_turnoff();
227 else {
228 /* wim: shouldn't there be a: del_timer(&timer); */
229 printk(KERN_CRIT PFX
230 "device file closed unexpectedly. Will not stop the WDT!\n");
231 }
232 clear_bit(0, &wdt_is_open);
233 wdt_expect_close = 0;
234 return 0;
235}
236
237static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
238{
239 void __user *argp = (void __user *)arg;
240 int __user *p = argp;
241 static const struct watchdog_info ident = {
242 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
243 | WDIOF_MAGICCLOSE,
244 .firmware_version = 1,
245 .identity = "ALiM7101",
246 };
247
248 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);
254 case WDIOC_SETOPTIONS:
255 {
256 int new_options, retval = -EINVAL;
257
258 if (get_user(new_options, p))
259 return -EFAULT;
260 if (new_options & WDIOS_DISABLECARD) {
261 wdt_turnoff();
262 retval = 0;
263 }
264 if (new_options & WDIOS_ENABLECARD) {
265 wdt_startup();
266 retval = 0;
267 }
268 return retval;
269 }
270 case WDIOC_KEEPALIVE:
271 wdt_keepalive();
272 return 0;
273 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;
290 }
291}
292
293static const struct file_operations wdt_fops = {
294 .owner = THIS_MODULE,
295 .llseek = no_llseek,
296 .write = fop_write,
297 .open = fop_open,
298 .release = fop_close,
299 .unlocked_ioctl = fop_ioctl,
300};
301
302static struct miscdevice wdt_miscdev = {
303 .minor = WATCHDOG_MINOR,
304 .name = "watchdog",
305 .fops = &wdt_fops,
306};
307
308/*
309 * Notifier for system down
310 */
311
312static int wdt_notify_sys(struct notifier_block *this,
313 unsigned long code, void *unused)
314{
315 if (code == SYS_DOWN || code == SYS_HALT)
316 wdt_turnoff();
317
318 if (code == SYS_RESTART) {
319 /*
320 * 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
323 */
324 wdt_change(WDT_ENABLE);
325 printk(KERN_INFO PFX "Watchdog timer is now enabled "
326 "with no heartbeat - should reboot in ~1 second.\n");
327 }
328 return NOTIFY_DONE;
329}
330
331/*
332 * The WDT needs to learn about soft shutdowns in order to
333 * turn the timebomb registers off.
334 */
335
336static struct notifier_block wdt_notifier = {
337 .notifier_call = wdt_notify_sys,
338};
339
340static void __exit alim7101_wdt_unload(void)
341{
342 wdt_turnoff();
343 /* Deregister */
344 misc_deregister(&wdt_miscdev);
345 unregister_reboot_notifier(&wdt_notifier);
346 pci_dev_put(alim7101_pmu);
347}
348
349static int __init alim7101_wdt_init(void)
350{
351 int rc = -EBUSY;
352 struct pci_dev *ali1543_south;
353 char tmp;
354
355 printk(KERN_INFO PFX "Steve Hill <steve@navaho.co.uk>.\n");
356 alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
357 NULL);
358 if (!alim7101_pmu) {
359 printk(KERN_INFO PFX
360 "ALi M7101 PMU not present - WDT not set\n");
361 return -EBUSY;
362 }
363
364 /* Set the WDT in the PMU to 1 second */
365 pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02);
366
367 ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
368 NULL);
369 if (!ali1543_south) {
370 printk(KERN_INFO PFX
371 "ALi 1543 South-Bridge not present - WDT not set\n");
372 goto err_out;
373 }
374 pci_read_config_byte(ali1543_south, 0x5e, &tmp);
375 pci_dev_put(ali1543_south);
376 if ((tmp & 0x1e) == 0x00) {
377 if (!use_gpio) {
378 printk(KERN_INFO PFX
379 "Detected old alim7101 revision 'a1d'. "
380 "If this is a cobalt board, set the 'use_gpio' "
381 "module parameter.\n");
382 goto err_out;
383 }
384 nowayout = 1;
385 } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
386 printk(KERN_INFO PFX
387 "ALi 1543 South-Bridge does not have the correct "
388 "revision number (???1001?) - WDT not set\n");
389 goto err_out;
390 }
391
392 if (timeout < 1 || timeout > 3600) {
393 /* arbitrary upper limit */
394 timeout = WATCHDOG_TIMEOUT;
395 printk(KERN_INFO PFX
396 "timeout value must be 1 <= x <= 3600, using %d\n",
397 timeout);
398 }
399
400 rc = register_reboot_notifier(&wdt_notifier);
401 if (rc) {
402 printk(KERN_ERR PFX
403 "cannot register reboot notifier (err=%d)\n", rc);
404 goto err_out;
405 }
406
407 rc = misc_register(&wdt_miscdev);
408 if (rc) {
409 printk(KERN_ERR PFX
410 "cannot register miscdev on minor=%d (err=%d)\n",
411 wdt_miscdev.minor, rc);
412 goto err_out_reboot;
413 }
414
415 if (nowayout)
416 __module_get(THIS_MODULE);
417
418 printk(KERN_INFO PFX "WDT driver for ALi M7101 initialised. "
419 "timeout=%d sec (nowayout=%d)\n",
420 timeout, nowayout);
421 return 0;
422
423err_out_reboot:
424 unregister_reboot_notifier(&wdt_notifier);
425err_out:
426 pci_dev_put(alim7101_pmu);
427 return rc;
428}
429
430module_init(alim7101_wdt_init);
431module_exit(alim7101_wdt_unload);
432
433static DEFINE_PCI_DEVICE_TABLE(alim7101_pci_tbl) __used = {
434 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
435 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
436 { }
437};
438
439MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);
440
441MODULE_AUTHOR("Steve Hill");
442MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
443MODULE_LICENSE("GPL");
444MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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
22#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
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>
36#include <linux/io.h>
37#include <linux/uaccess.h>
38
39
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 */
61/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
62static int timeout = WATCHDOG_TIMEOUT;
63module_param(timeout, int, 0);
64MODULE_PARM_DESC(timeout,
65 "Watchdog timeout in seconds. (1<=timeout<=3600, default="
66 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
67
68static int use_gpio; /* Use the pic (for a1d revision alim7101) */
69module_param(use_gpio, int, 0);
70MODULE_PARM_DESC(use_gpio,
71 "Use the gpio watchdog (required by old cobalt boards).");
72
73static void wdt_timer_ping(unsigned long);
74static DEFINE_TIMER(timer, wdt_timer_ping, 0, 1);
75static unsigned long next_heartbeat;
76static unsigned long wdt_is_open;
77static char wdt_expect_close;
78static struct pci_dev *alim7101_pmu;
79
80static bool nowayout = WATCHDOG_NOWAYOUT;
81module_param(nowayout, bool, 0);
82MODULE_PARM_DESC(nowayout,
83 "Watchdog cannot be stopped once started (default="
84 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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 */
95 char tmp;
96
97 if (time_before(jiffies, next_heartbeat)) {
98 /* Ping the WDT (this is actually a disarm/arm sequence) */
99 pci_read_config_byte(alim7101_pmu, 0x92, &tmp);
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));
104 if (use_gpio) {
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);
111 }
112 } else {
113 pr_warn("Heartbeat lost! Will not ping the watchdog\n");
114 }
115 /* Re-set the timer interval */
116 mod_timer(&timer, jiffies + WDT_INTERVAL);
117}
118
119/*
120 * Utility routines
121 */
122
123static void wdt_change(int writeval)
124{
125 char tmp;
126
127 pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp);
128 if (writeval == WDT_ENABLE) {
129 pci_write_config_byte(alim7101_pmu,
130 ALI_7101_WDT, (tmp | ALI_WDT_ARM));
131 if (use_gpio) {
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);
136 }
137
138 } else {
139 pci_write_config_byte(alim7101_pmu,
140 ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
141 if (use_gpio) {
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);
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 */
160 mod_timer(&timer, jiffies + WDT_INTERVAL);
161
162 pr_info("Watchdog timer is now enabled\n");
163}
164
165static void wdt_turnoff(void)
166{
167 /* Stop the timer */
168 del_timer_sync(&timer);
169 wdt_change(WDT_DISABLE);
170 pr_info("Watchdog timer is now disabled...\n");
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
183static ssize_t fop_write(struct file *file, const char __user *buf,
184 size_t count, loff_t *ppos)
185{
186 /* See if we got the magic character 'V' and reload the timer */
187 if (count) {
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;
198 if (get_user(c, buf + ofs))
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
210static int fop_open(struct inode *inode, struct file *file)
211{
212 /* Just in case we're already talking to someone... */
213 if (test_and_set_bit(0, &wdt_is_open))
214 return -EBUSY;
215 /* Good, fire up the show */
216 wdt_startup();
217 return nonseekable_open(inode, file);
218}
219
220static int fop_close(struct inode *inode, struct file *file)
221{
222 if (wdt_expect_close == 42)
223 wdt_turnoff();
224 else {
225 /* wim: shouldn't there be a: del_timer(&timer); */
226 pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
227 }
228 clear_bit(0, &wdt_is_open);
229 wdt_expect_close = 0;
230 return 0;
231}
232
233static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
234{
235 void __user *argp = (void __user *)arg;
236 int __user *p = argp;
237 static const struct watchdog_info ident = {
238 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
239 | WDIOF_MAGICCLOSE,
240 .firmware_version = 1,
241 .identity = "ALiM7101",
242 };
243
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);
250 case WDIOC_SETOPTIONS:
251 {
252 int new_options, retval = -EINVAL;
253
254 if (get_user(new_options, p))
255 return -EFAULT;
256 if (new_options & WDIOS_DISABLECARD) {
257 wdt_turnoff();
258 retval = 0;
259 }
260 if (new_options & WDIOS_ENABLECARD) {
261 wdt_startup();
262 retval = 0;
263 }
264 return retval;
265 }
266 case WDIOC_KEEPALIVE:
267 wdt_keepalive();
268 return 0;
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;
286 }
287}
288
289static const struct file_operations wdt_fops = {
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,
296};
297
298static struct miscdevice wdt_miscdev = {
299 .minor = WATCHDOG_MINOR,
300 .name = "watchdog",
301 .fops = &wdt_fops,
302};
303
304/*
305 * Notifier for system down
306 */
307
308static int wdt_notify_sys(struct notifier_block *this,
309 unsigned long code, void *unused)
310{
311 if (code == SYS_DOWN || code == SYS_HALT)
312 wdt_turnoff();
313
314 if (code == SYS_RESTART) {
315 /*
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
319 */
320 wdt_change(WDT_ENABLE);
321 pr_info("Watchdog timer is now enabled with no heartbeat - should reboot in ~1 second\n");
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
331static struct notifier_block wdt_notifier = {
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);
341 pci_dev_put(alim7101_pmu);
342}
343
344static int __init alim7101_wdt_init(void)
345{
346 int rc = -EBUSY;
347 struct pci_dev *ali1543_south;
348 char tmp;
349
350 pr_info("Steve Hill <steve@navaho.co.uk>\n");
351 alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
352 NULL);
353 if (!alim7101_pmu) {
354 pr_info("ALi M7101 PMU not present - WDT not set\n");
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
361 ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
362 NULL);
363 if (!ali1543_south) {
364 pr_info("ALi 1543 South-Bridge not present - WDT not set\n");
365 goto err_out;
366 }
367 pci_read_config_byte(ali1543_south, 0x5e, &tmp);
368 pci_dev_put(ali1543_south);
369 if ((tmp & 0x1e) == 0x00) {
370 if (!use_gpio) {
371 pr_info("Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n");
372 goto err_out;
373 }
374 nowayout = 1;
375 } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
376 pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
377 goto err_out;
378 }
379
380 if (timeout < 1 || timeout > 3600) {
381 /* arbitrary upper limit */
382 timeout = WATCHDOG_TIMEOUT;
383 pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
384 timeout);
385 }
386
387 rc = register_reboot_notifier(&wdt_notifier);
388 if (rc) {
389 pr_err("cannot register reboot notifier (err=%d)\n", rc);
390 goto err_out;
391 }
392
393 rc = misc_register(&wdt_miscdev);
394 if (rc) {
395 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
396 wdt_miscdev.minor, rc);
397 goto err_out_reboot;
398 }
399
400 if (nowayout)
401 __module_get(THIS_MODULE);
402
403 pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
404 timeout, nowayout);
405 return 0;
406
407err_out_reboot:
408 unregister_reboot_notifier(&wdt_notifier);
409err_out:
410 pci_dev_put(alim7101_pmu);
411 return rc;
412}
413
414module_init(alim7101_wdt_init);
415module_exit(alim7101_wdt_unload);
416
417static const struct pci_device_id alim7101_pci_tbl[] __used = {
418 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
419 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
420 { }
421};
422
423MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);
424
425MODULE_AUTHOR("Steve Hill");
426MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
427MODULE_LICENSE("GPL");