Loading...
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 fallthrough;
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 .compat_ioctl = compat_ptr_ioctl,
298};
299
300static struct miscdevice wdt_miscdev = {
301 .minor = WATCHDOG_MINOR,
302 .name = "watchdog",
303 .fops = &wdt_fops,
304};
305
306static int wdt_restart_handle(struct notifier_block *this, unsigned long mode,
307 void *cmd)
308{
309 /*
310 * Cobalt devices have no way of rebooting themselves other
311 * than getting the watchdog to pull reset, so we restart the
312 * watchdog on reboot with no heartbeat.
313 */
314 wdt_change(WDT_ENABLE);
315
316 /* loop until the watchdog fires */
317 while (true)
318 ;
319
320 return NOTIFY_DONE;
321}
322
323static struct notifier_block wdt_restart_handler = {
324 .notifier_call = wdt_restart_handle,
325 .priority = 128,
326};
327
328/*
329 * Notifier for system down
330 */
331
332static int wdt_notify_sys(struct notifier_block *this,
333 unsigned long code, void *unused)
334{
335 if (code == SYS_DOWN || code == SYS_HALT)
336 wdt_turnoff();
337
338 return NOTIFY_DONE;
339}
340
341/*
342 * The WDT needs to learn about soft shutdowns in order to
343 * turn the timebomb registers off.
344 */
345
346static struct notifier_block wdt_notifier = {
347 .notifier_call = wdt_notify_sys,
348};
349
350static void __exit alim7101_wdt_unload(void)
351{
352 wdt_turnoff();
353 /* Deregister */
354 misc_deregister(&wdt_miscdev);
355 unregister_reboot_notifier(&wdt_notifier);
356 unregister_restart_handler(&wdt_restart_handler);
357 pci_dev_put(alim7101_pmu);
358}
359
360static int __init alim7101_wdt_init(void)
361{
362 int rc = -EBUSY;
363 struct pci_dev *ali1543_south;
364 char tmp;
365
366 pr_info("Steve Hill <steve@navaho.co.uk>\n");
367 alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
368 NULL);
369 if (!alim7101_pmu) {
370 pr_info("ALi M7101 PMU not present - WDT not set\n");
371 return -EBUSY;
372 }
373
374 /* Set the WDT in the PMU to 1 second */
375 pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02);
376
377 ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
378 NULL);
379 if (!ali1543_south) {
380 pr_info("ALi 1543 South-Bridge not present - WDT not set\n");
381 goto err_out;
382 }
383 pci_read_config_byte(ali1543_south, 0x5e, &tmp);
384 pci_dev_put(ali1543_south);
385 if ((tmp & 0x1e) == 0x00) {
386 if (!use_gpio) {
387 pr_info("Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n");
388 goto err_out;
389 }
390 nowayout = 1;
391 } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
392 pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
393 goto err_out;
394 }
395
396 if (timeout < 1 || timeout > 3600) {
397 /* arbitrary upper limit */
398 timeout = WATCHDOG_TIMEOUT;
399 pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
400 timeout);
401 }
402
403 rc = register_reboot_notifier(&wdt_notifier);
404 if (rc) {
405 pr_err("cannot register reboot notifier (err=%d)\n", rc);
406 goto err_out;
407 }
408
409 rc = register_restart_handler(&wdt_restart_handler);
410 if (rc) {
411 pr_err("cannot register restart handler (err=%d)\n", rc);
412 goto err_out_reboot;
413 }
414
415 rc = misc_register(&wdt_miscdev);
416 if (rc) {
417 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
418 wdt_miscdev.minor, rc);
419 goto err_out_restart;
420 }
421
422 if (nowayout)
423 __module_get(THIS_MODULE);
424
425 pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
426 timeout, nowayout);
427 return 0;
428
429err_out_restart:
430 unregister_restart_handler(&wdt_restart_handler);
431err_out_reboot:
432 unregister_reboot_notifier(&wdt_notifier);
433err_out:
434 pci_dev_put(alim7101_pmu);
435 return rc;
436}
437
438module_init(alim7101_wdt_init);
439module_exit(alim7101_wdt_unload);
440
441static const struct pci_device_id alim7101_pci_tbl[] __used = {
442 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
443 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
444 { }
445};
446
447MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);
448
449MODULE_AUTHOR("Steve Hill");
450MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
451MODULE_LICENSE("GPL");
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(struct timer_list *);
74static DEFINE_TIMER(timer, wdt_timer_ping);
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(struct timer_list *unused)
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
304static int wdt_restart_handle(struct notifier_block *this, unsigned long mode,
305 void *cmd)
306{
307 /*
308 * Cobalt devices have no way of rebooting themselves other
309 * than getting the watchdog to pull reset, so we restart the
310 * watchdog on reboot with no heartbeat.
311 */
312 wdt_change(WDT_ENABLE);
313
314 /* loop until the watchdog fires */
315 while (true)
316 ;
317
318 return NOTIFY_DONE;
319}
320
321static struct notifier_block wdt_restart_handler = {
322 .notifier_call = wdt_restart_handle,
323 .priority = 128,
324};
325
326/*
327 * Notifier for system down
328 */
329
330static int wdt_notify_sys(struct notifier_block *this,
331 unsigned long code, void *unused)
332{
333 if (code == SYS_DOWN || code == SYS_HALT)
334 wdt_turnoff();
335
336 return NOTIFY_DONE;
337}
338
339/*
340 * The WDT needs to learn about soft shutdowns in order to
341 * turn the timebomb registers off.
342 */
343
344static struct notifier_block wdt_notifier = {
345 .notifier_call = wdt_notify_sys,
346};
347
348static void __exit alim7101_wdt_unload(void)
349{
350 wdt_turnoff();
351 /* Deregister */
352 misc_deregister(&wdt_miscdev);
353 unregister_reboot_notifier(&wdt_notifier);
354 unregister_restart_handler(&wdt_restart_handler);
355 pci_dev_put(alim7101_pmu);
356}
357
358static int __init alim7101_wdt_init(void)
359{
360 int rc = -EBUSY;
361 struct pci_dev *ali1543_south;
362 char tmp;
363
364 pr_info("Steve Hill <steve@navaho.co.uk>\n");
365 alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101,
366 NULL);
367 if (!alim7101_pmu) {
368 pr_info("ALi M7101 PMU not present - WDT not set\n");
369 return -EBUSY;
370 }
371
372 /* Set the WDT in the PMU to 1 second */
373 pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02);
374
375 ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533,
376 NULL);
377 if (!ali1543_south) {
378 pr_info("ALi 1543 South-Bridge not present - WDT not set\n");
379 goto err_out;
380 }
381 pci_read_config_byte(ali1543_south, 0x5e, &tmp);
382 pci_dev_put(ali1543_south);
383 if ((tmp & 0x1e) == 0x00) {
384 if (!use_gpio) {
385 pr_info("Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n");
386 goto err_out;
387 }
388 nowayout = 1;
389 } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) {
390 pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n");
391 goto err_out;
392 }
393
394 if (timeout < 1 || timeout > 3600) {
395 /* arbitrary upper limit */
396 timeout = WATCHDOG_TIMEOUT;
397 pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
398 timeout);
399 }
400
401 rc = register_reboot_notifier(&wdt_notifier);
402 if (rc) {
403 pr_err("cannot register reboot notifier (err=%d)\n", rc);
404 goto err_out;
405 }
406
407 rc = register_restart_handler(&wdt_restart_handler);
408 if (rc) {
409 pr_err("cannot register restart handler (err=%d)\n", rc);
410 goto err_out_reboot;
411 }
412
413 rc = misc_register(&wdt_miscdev);
414 if (rc) {
415 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
416 wdt_miscdev.minor, rc);
417 goto err_out_restart;
418 }
419
420 if (nowayout)
421 __module_get(THIS_MODULE);
422
423 pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n",
424 timeout, nowayout);
425 return 0;
426
427err_out_restart:
428 unregister_restart_handler(&wdt_restart_handler);
429err_out_reboot:
430 unregister_reboot_notifier(&wdt_notifier);
431err_out:
432 pci_dev_put(alim7101_pmu);
433 return rc;
434}
435
436module_init(alim7101_wdt_init);
437module_exit(alim7101_wdt_unload);
438
439static const struct pci_device_id alim7101_pci_tbl[] __used = {
440 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) },
441 { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) },
442 { }
443};
444
445MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl);
446
447MODULE_AUTHOR("Steve Hill");
448MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver");
449MODULE_LICENSE("GPL");