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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// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * ALi M7101 PMU Computer Watchdog Timer driver
4 *
5 * Based on w83877f_wdt.c by Scott Jennings <linuxdrivers@oro.net>
6 * and the Cobalt kernel WDT timer driver by Tim Hockin
7 * <thockin@cobaltnet.com>
8 *
9 * (c)2002 Steve Hill <steve@navaho.co.uk>
10 *
11 * This WDT driver is different from most other Linux WDT
12 * drivers in that the driver will ping the watchdog by itself,
13 * because this particular WDT has a very short timeout (1.6
14 * seconds) and it would be insane to count on any userspace
15 * daemon always getting scheduled within that time frame.
16 *
17 * Additions:
18 * Aug 23, 2004 - Added use_gpio module parameter for use on revision a1d PMUs
19 * found on very old cobalt hardware.
20 * -- Mike Waychison <michael.waychison@sun.com>
21 */
22
23#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24
25#include <linux/module.h>
26#include <linux/moduleparam.h>
27#include <linux/types.h>
28#include <linux/timer.h>
29#include <linux/miscdevice.h>
30#include <linux/watchdog.h>
31#include <linux/ioport.h>
32#include <linux/notifier.h>
33#include <linux/reboot.h>
34#include <linux/init.h>
35#include <linux/fs.h>
36#include <linux/pci.h>
37#include <linux/io.h>
38#include <linux/uaccess.h>
39
40
41#define WDT_ENABLE 0x9C
42#define WDT_DISABLE 0x8C
43
44#define ALI_7101_WDT 0x92
45#define ALI_7101_GPIO 0x7D
46#define ALI_7101_GPIO_O 0x7E
47#define ALI_WDT_ARM 0x01
48
49/*
50 * We're going to use a 1 second timeout.
51 * If we reset the watchdog every ~250ms we should be safe. */
52
53#define WDT_INTERVAL (HZ/4+1)
54
55/*
56 * We must not require too good response from the userspace daemon.
57 * Here we require the userspace daemon to send us a heartbeat
58 * char to /dev/watchdog every 30 seconds.
59 */
60
61#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
62/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
63static int timeout = WATCHDOG_TIMEOUT;
64module_param(timeout, int, 0);
65MODULE_PARM_DESC(timeout,
66 "Watchdog timeout in seconds. (1<=timeout<=3600, default="
67 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
68
69static int use_gpio; /* Use the pic (for a1d revision alim7101) */
70module_param(use_gpio, int, 0);
71MODULE_PARM_DESC(use_gpio,
72 "Use the gpio watchdog (required by old cobalt boards).");
73
74static void wdt_timer_ping(struct timer_list *);
75static DEFINE_TIMER(timer, wdt_timer_ping);
76static unsigned long next_heartbeat;
77static unsigned long wdt_is_open;
78static char wdt_expect_close;
79static struct pci_dev *alim7101_pmu;
80
81static bool nowayout = WATCHDOG_NOWAYOUT;
82module_param(nowayout, bool, 0);
83MODULE_PARM_DESC(nowayout,
84 "Watchdog cannot be stopped once started (default="
85 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
86
87/*
88 * Whack the dog
89 */
90
91static void wdt_timer_ping(struct timer_list *unused)
92{
93 /* If we got a heartbeat pulse within the WDT_US_INTERVAL
94 * we agree to ping the WDT
95 */
96 char tmp;
97
98 if (time_before(jiffies, next_heartbeat)) {
99 /* Ping the WDT (this is actually a disarm/arm sequence) */
100 pci_read_config_byte(alim7101_pmu, 0x92, &tmp);
101 pci_write_config_byte(alim7101_pmu,
102 ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
103 pci_write_config_byte(alim7101_pmu,
104 ALI_7101_WDT, (tmp | ALI_WDT_ARM));
105 if (use_gpio) {
106 pci_read_config_byte(alim7101_pmu,
107 ALI_7101_GPIO_O, &tmp);
108 pci_write_config_byte(alim7101_pmu,
109 ALI_7101_GPIO_O, tmp | 0x20);
110 pci_write_config_byte(alim7101_pmu,
111 ALI_7101_GPIO_O, tmp & ~0x20);
112 }
113 } else {
114 pr_warn("Heartbeat lost! Will not ping the watchdog\n");
115 }
116 /* Re-set the timer interval */
117 mod_timer(&timer, jiffies + WDT_INTERVAL);
118}
119
120/*
121 * Utility routines
122 */
123
124static void wdt_change(int writeval)
125{
126 char tmp;
127
128 pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp);
129 if (writeval == WDT_ENABLE) {
130 pci_write_config_byte(alim7101_pmu,
131 ALI_7101_WDT, (tmp | ALI_WDT_ARM));
132 if (use_gpio) {
133 pci_read_config_byte(alim7101_pmu,
134 ALI_7101_GPIO_O, &tmp);
135 pci_write_config_byte(alim7101_pmu,
136 ALI_7101_GPIO_O, tmp & ~0x20);
137 }
138
139 } else {
140 pci_write_config_byte(alim7101_pmu,
141 ALI_7101_WDT, (tmp & ~ALI_WDT_ARM));
142 if (use_gpio) {
143 pci_read_config_byte(alim7101_pmu,
144 ALI_7101_GPIO_O, &tmp);
145 pci_write_config_byte(alim7101_pmu,
146 ALI_7101_GPIO_O, tmp | 0x20);
147 }
148 }
149}
150
151static void wdt_startup(void)
152{
153 next_heartbeat = jiffies + (timeout * HZ);
154
155 /* We must enable before we kick off the timer in case the timer
156 occurs as we ping it */
157
158 wdt_change(WDT_ENABLE);
159
160 /* Start the timer */
161 mod_timer(&timer, jiffies + WDT_INTERVAL);
162
163 pr_info("Watchdog timer is now enabled\n");
164}
165
166static void wdt_turnoff(void)
167{
168 /* Stop the timer */
169 del_timer_sync(&timer);
170 wdt_change(WDT_DISABLE);
171 pr_info("Watchdog timer is now disabled...\n");
172}
173
174static void wdt_keepalive(void)
175{
176 /* user land ping */
177 next_heartbeat = jiffies + (timeout * HZ);
178}
179
180/*
181 * /dev/watchdog handling
182 */
183
184static ssize_t fop_write(struct file *file, const char __user *buf,
185 size_t count, loff_t *ppos)
186{
187 /* See if we got the magic character 'V' and reload the timer */
188 if (count) {
189 if (!nowayout) {
190 size_t ofs;
191
192 /* note: just in case someone wrote the magic character
193 * five months ago... */
194 wdt_expect_close = 0;
195
196 /* now scan */
197 for (ofs = 0; ofs != count; ofs++) {
198 char c;
199 if (get_user(c, buf + ofs))
200 return -EFAULT;
201 if (c == 'V')
202 wdt_expect_close = 42;
203 }
204 }
205 /* someone wrote to us, we should restart timer */
206 wdt_keepalive();
207 }
208 return count;
209}
210
211static int fop_open(struct inode *inode, struct file *file)
212{
213 /* Just in case we're already talking to someone... */
214 if (test_and_set_bit(0, &wdt_is_open))
215 return -EBUSY;
216 /* Good, fire up the show */
217 wdt_startup();
218 return stream_open(inode, file);
219}
220
221static int fop_close(struct inode *inode, struct file *file)
222{
223 if (wdt_expect_close == 42)
224 wdt_turnoff();
225 else {
226 /* wim: shouldn't there be a: del_timer(&timer); */
227 pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
228 }
229 clear_bit(0, &wdt_is_open);
230 wdt_expect_close = 0;
231 return 0;
232}
233
234static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
235{
236 void __user *argp = (void __user *)arg;
237 int __user *p = argp;
238 static const struct watchdog_info ident = {
239 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
240 | WDIOF_MAGICCLOSE,
241 .firmware_version = 1,
242 .identity = "ALiM7101",
243 };
244
245 switch (cmd) {
246 case WDIOC_GETSUPPORT:
247 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
248 case WDIOC_GETSTATUS:
249 case WDIOC_GETBOOTSTATUS:
250 return put_user(0, p);
251 case WDIOC_SETOPTIONS:
252 {
253 int new_options, retval = -EINVAL;
254
255 if (get_user(new_options, p))
256 return -EFAULT;
257 if (new_options & WDIOS_DISABLECARD) {
258 wdt_turnoff();
259 retval = 0;
260 }
261 if (new_options & WDIOS_ENABLECARD) {
262 wdt_startup();
263 retval = 0;
264 }
265 return retval;
266 }
267 case WDIOC_KEEPALIVE:
268 wdt_keepalive();
269 return 0;
270 case WDIOC_SETTIMEOUT:
271 {
272 int new_timeout;
273
274 if (get_user(new_timeout, p))
275 return -EFAULT;
276 /* arbitrary upper limit */
277 if (new_timeout < 1 || new_timeout > 3600)
278 return -EINVAL;
279 timeout = new_timeout;
280 wdt_keepalive();
281 }
282 /* Fall through */
283 case WDIOC_GETTIMEOUT:
284 return put_user(timeout, p);
285 default:
286 return -ENOTTY;
287 }
288}
289
290static const struct file_operations wdt_fops = {
291 .owner = THIS_MODULE,
292 .llseek = no_llseek,
293 .write = fop_write,
294 .open = fop_open,
295 .release = fop_close,
296 .unlocked_ioctl = fop_ioctl,
297};
298
299static struct miscdevice wdt_miscdev = {
300 .minor = WATCHDOG_MINOR,
301 .name = "watchdog",
302 .fops = &wdt_fops,
303};
304
305static int wdt_restart_handle(struct notifier_block *this, unsigned long mode,
306 void *cmd)
307{
308 /*
309 * Cobalt devices have no way of rebooting themselves other
310 * than getting the watchdog to pull reset, so we restart the
311 * watchdog on reboot with no heartbeat.
312 */
313 wdt_change(WDT_ENABLE);
314
315 /* loop until the watchdog fires */
316 while (true)
317 ;
318
319 return NOTIFY_DONE;
320}
321
322static struct notifier_block wdt_restart_handler = {
323 .notifier_call = wdt_restart_handle,
324 .priority = 128,
325};
326
327/*
328 * Notifier for system down
329 */
330
331static int wdt_notify_sys(struct notifier_block *this,
332 unsigned long code, void *unused)
333{
334 if (code == SYS_DOWN || code == SYS_HALT)
335 wdt_turnoff();
336
337 return NOTIFY_DONE;
338}
339
340/*
341 * The WDT needs to learn about soft shutdowns in order to
342 * turn the timebomb registers off.
343 */
344
345static struct notifier_block wdt_notifier = {
346 .notifier_call = wdt_notify_sys,
347};
348
349static void __exit alim7101_wdt_unload(void)
350{
351 wdt_turnoff();
352 /* Deregister */
353 misc_deregister(&wdt_miscdev);
354 unregister_reboot_notifier(&wdt_notifier);
355 unregister_restart_handler(&wdt_restart_handler);
356 pci_dev_put(alim7101_pmu);
357}
358
359static int __init alim7101_wdt_init(void)
360{
361 int rc = -EBUSY;
362 struct pci_dev *ali1543_south;
363 char tmp;
364
365 pr_info("Steve Hill <steve@navaho.co.uk>\n");
366 alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
367 NULL);
368 if (!alim7101_pmu) {
369 pr_info("ALi M7101 PMU not present - WDT not set\n");
370 return -EBUSY;
371 }
372
373 /* Set the WDT in the PMU to 1 second */
374 pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02);
375
376 ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
377 NULL);
378 if (!ali1543_south) {
379 pr_info("ALi 1543 South-Bridge not present - WDT not set\n");
380 goto err_out;
381 }
382 pci_read_config_byte(ali1543_south, 0x5e, &tmp);
383 pci_dev_put(ali1543_south);
384 if ((tmp & 0x1e) == 0x00) {
385 if (!use_gpio) {
386 pr_info("Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n");
387 goto err_out;
388 }
389 nowayout = 1;
390 } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
391 pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
392 goto err_out;
393 }
394
395 if (timeout < 1 || timeout > 3600) {
396 /* arbitrary upper limit */
397 timeout = WATCHDOG_TIMEOUT;
398 pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
399 timeout);
400 }
401
402 rc = register_reboot_notifier(&wdt_notifier);
403 if (rc) {
404 pr_err("cannot register reboot notifier (err=%d)\n", rc);
405 goto err_out;
406 }
407
408 rc = register_restart_handler(&wdt_restart_handler);
409 if (rc) {
410 pr_err("cannot register restart handler (err=%d)\n", rc);
411 goto err_out_reboot;
412 }
413
414 rc = misc_register(&wdt_miscdev);
415 if (rc) {
416 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
417 wdt_miscdev.minor, rc);
418 goto err_out_restart;
419 }
420
421 if (nowayout)
422 __module_get(THIS_MODULE);
423
424 pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
425 timeout, nowayout);
426 return 0;
427
428err_out_restart:
429 unregister_restart_handler(&wdt_restart_handler);
430err_out_reboot:
431 unregister_reboot_notifier(&wdt_notifier);
432err_out:
433 pci_dev_put(alim7101_pmu);
434 return rc;
435}
436
437module_init(alim7101_wdt_init);
438module_exit(alim7101_wdt_unload);
439
440static const struct pci_device_id alim7101_pci_tbl[] __used = {
441 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
442 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
443 { }
444};
445
446MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);
447
448MODULE_AUTHOR("Steve Hill");
449MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
450MODULE_LICENSE("GPL");