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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Watchdog for the 7101 PMU version found in the ALi M1535 chipsets
4 */
5
6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8#include <linux/module.h>
9#include <linux/moduleparam.h>
10#include <linux/types.h>
11#include <linux/miscdevice.h>
12#include <linux/watchdog.h>
13#include <linux/ioport.h>
14#include <linux/notifier.h>
15#include <linux/reboot.h>
16#include <linux/init.h>
17#include <linux/fs.h>
18#include <linux/pci.h>
19#include <linux/uaccess.h>
20#include <linux/io.h>
21
22#define WATCHDOG_NAME "ALi_M1535"
23#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
24
25/* internal variables */
26static unsigned long ali_is_open;
27static char ali_expect_release;
28static struct pci_dev *ali_pci;
29static u32 ali_timeout_bits; /* stores the computed timeout */
30static DEFINE_SPINLOCK(ali_lock); /* Guards the hardware */
31
32/* module parameters */
33static int timeout = WATCHDOG_TIMEOUT;
34module_param(timeout, int, 0);
35MODULE_PARM_DESC(timeout,
36 "Watchdog timeout in seconds. (0 < timeout < 18000, default="
37 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
38
39static bool nowayout = WATCHDOG_NOWAYOUT;
40module_param(nowayout, bool, 0);
41MODULE_PARM_DESC(nowayout,
42 "Watchdog cannot be stopped once started (default="
43 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
44
45/*
46 * ali_start - start watchdog countdown
47 *
48 * Starts the timer running providing the timer has a counter
49 * configuration set.
50 */
51
52static void ali_start(void)
53{
54 u32 val;
55
56 spin_lock(&ali_lock);
57
58 pci_read_config_dword(ali_pci, 0xCC, &val);
59 val &= ~0x3F; /* Mask count */
60 val |= (1 << 25) | ali_timeout_bits;
61 pci_write_config_dword(ali_pci, 0xCC, val);
62
63 spin_unlock(&ali_lock);
64}
65
66/*
67 * ali_stop - stop the timer countdown
68 *
69 * Stop the ALi watchdog countdown
70 */
71
72static void ali_stop(void)
73{
74 u32 val;
75
76 spin_lock(&ali_lock);
77
78 pci_read_config_dword(ali_pci, 0xCC, &val);
79 val &= ~0x3F; /* Mask count to zero (disabled) */
80 val &= ~(1 << 25); /* and for safety mask the reset enable */
81 pci_write_config_dword(ali_pci, 0xCC, val);
82
83 spin_unlock(&ali_lock);
84}
85
86/*
87 * ali_keepalive - send a keepalive to the watchdog
88 *
89 * Send a keepalive to the timer (actually we restart the timer).
90 */
91
92static void ali_keepalive(void)
93{
94 ali_start();
95}
96
97/*
98 * ali_settimer - compute the timer reload value
99 * @t: time in seconds
100 *
101 * Computes the timeout values needed
102 */
103
104static int ali_settimer(int t)
105{
106 if (t < 0)
107 return -EINVAL;
108 else if (t < 60)
109 ali_timeout_bits = t|(1 << 6);
110 else if (t < 3600)
111 ali_timeout_bits = (t / 60)|(1 << 7);
112 else if (t < 18000)
113 ali_timeout_bits = (t / 300)|(1 << 6)|(1 << 7);
114 else
115 return -EINVAL;
116
117 timeout = t;
118 return 0;
119}
120
121/*
122 * /dev/watchdog handling
123 */
124
125/*
126 * ali_write - writes to ALi watchdog
127 * @file: file from VFS
128 * @data: user address of data
129 * @len: length of data
130 * @ppos: pointer to the file offset
131 *
132 * Handle a write to the ALi watchdog. Writing to the file pings
133 * the watchdog and resets it. Writing the magic 'V' sequence allows
134 * the next close to turn off the watchdog.
135 */
136
137static ssize_t ali_write(struct file *file, const char __user *data,
138 size_t len, loff_t *ppos)
139{
140 /* See if we got the magic character 'V' and reload the timer */
141 if (len) {
142 if (!nowayout) {
143 size_t i;
144
145 /* note: just in case someone wrote the
146 magic character five months ago... */
147 ali_expect_release = 0;
148
149 /* scan to see whether or not we got
150 the magic character */
151 for (i = 0; i != len; i++) {
152 char c;
153 if (get_user(c, data + i))
154 return -EFAULT;
155 if (c == 'V')
156 ali_expect_release = 42;
157 }
158 }
159
160 /* someone wrote to us, we should reload the timer */
161 ali_start();
162 }
163 return len;
164}
165
166/*
167 * ali_ioctl - handle watchdog ioctls
168 * @file: VFS file pointer
169 * @cmd: ioctl number
170 * @arg: arguments to the ioctl
171 *
172 * Handle the watchdog ioctls supported by the ALi driver. Really
173 * we want an extension to enable irq ack monitoring and the like
174 */
175
176static long ali_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
177{
178 void __user *argp = (void __user *)arg;
179 int __user *p = argp;
180 static const struct watchdog_info ident = {
181 .options = WDIOF_KEEPALIVEPING |
182 WDIOF_SETTIMEOUT |
183 WDIOF_MAGICCLOSE,
184 .firmware_version = 0,
185 .identity = "ALi M1535 WatchDog Timer",
186 };
187
188 switch (cmd) {
189 case WDIOC_GETSUPPORT:
190 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
191
192 case WDIOC_GETSTATUS:
193 case WDIOC_GETBOOTSTATUS:
194 return put_user(0, p);
195 case WDIOC_SETOPTIONS:
196 {
197 int new_options, retval = -EINVAL;
198
199 if (get_user(new_options, p))
200 return -EFAULT;
201 if (new_options & WDIOS_DISABLECARD) {
202 ali_stop();
203 retval = 0;
204 }
205 if (new_options & WDIOS_ENABLECARD) {
206 ali_start();
207 retval = 0;
208 }
209 return retval;
210 }
211 case WDIOC_KEEPALIVE:
212 ali_keepalive();
213 return 0;
214 case WDIOC_SETTIMEOUT:
215 {
216 int new_timeout;
217 if (get_user(new_timeout, p))
218 return -EFAULT;
219 if (ali_settimer(new_timeout))
220 return -EINVAL;
221 ali_keepalive();
222 }
223 fallthrough;
224 case WDIOC_GETTIMEOUT:
225 return put_user(timeout, p);
226 default:
227 return -ENOTTY;
228 }
229}
230
231/*
232 * ali_open - handle open of ali watchdog
233 * @inode: inode from VFS
234 * @file: file from VFS
235 *
236 * Open the ALi watchdog device. Ensure only one person opens it
237 * at a time. Also start the watchdog running.
238 */
239
240static int ali_open(struct inode *inode, struct file *file)
241{
242 /* /dev/watchdog can only be opened once */
243 if (test_and_set_bit(0, &ali_is_open))
244 return -EBUSY;
245
246 /* Activate */
247 ali_start();
248 return stream_open(inode, file);
249}
250
251/*
252 * ali_release - close an ALi watchdog
253 * @inode: inode from VFS
254 * @file: file from VFS
255 *
256 * Close the ALi watchdog device. Actual shutdown of the timer
257 * only occurs if the magic sequence has been set.
258 */
259
260static int ali_release(struct inode *inode, struct file *file)
261{
262 /*
263 * Shut off the timer.
264 */
265 if (ali_expect_release == 42)
266 ali_stop();
267 else {
268 pr_crit("Unexpected close, not stopping watchdog!\n");
269 ali_keepalive();
270 }
271 clear_bit(0, &ali_is_open);
272 ali_expect_release = 0;
273 return 0;
274}
275
276/*
277 * ali_notify_sys - System down notifier
278 *
279 * Notifier for system down
280 */
281
282
283static int ali_notify_sys(struct notifier_block *this,
284 unsigned long code, void *unused)
285{
286 if (code == SYS_DOWN || code == SYS_HALT)
287 ali_stop(); /* Turn the WDT off */
288 return NOTIFY_DONE;
289}
290
291/*
292 * Data for PCI driver interface
293 *
294 * This data only exists for exporting the supported
295 * PCI ids via MODULE_DEVICE_TABLE. We do not actually
296 * register a pci_driver, because someone else might one day
297 * want to register another driver on the same PCI id.
298 */
299
300static const struct pci_device_id ali_pci_tbl[] __used = {
301 { PCI_VENDOR_ID_AL, 0x1533, PCI_ANY_ID, PCI_ANY_ID,},
302 { PCI_VENDOR_ID_AL, 0x1535, PCI_ANY_ID, PCI_ANY_ID,},
303 { 0, },
304};
305MODULE_DEVICE_TABLE(pci, ali_pci_tbl);
306
307/*
308 * ali_find_watchdog - find a 1535 and 7101
309 *
310 * Scans the PCI hardware for a 1535 series bridge and matching 7101
311 * watchdog device. This may be overtight but it is better to be safe
312 */
313
314static int __init ali_find_watchdog(void)
315{
316 struct pci_dev *pdev;
317 u32 wdog;
318
319 /* Check for a 1533/1535 series bridge */
320 pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1535, NULL);
321 if (pdev == NULL)
322 pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1533, NULL);
323 if (pdev == NULL)
324 return -ENODEV;
325 pci_dev_put(pdev);
326
327 /* Check for the a 7101 PMU */
328 pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x7101, NULL);
329 if (pdev == NULL)
330 return -ENODEV;
331
332 if (pci_enable_device(pdev)) {
333 pci_dev_put(pdev);
334 return -EIO;
335 }
336
337 ali_pci = pdev;
338
339 /*
340 * Initialize the timer bits
341 */
342 pci_read_config_dword(pdev, 0xCC, &wdog);
343
344 /* Timer bits */
345 wdog &= ~0x3F;
346 /* Issued events */
347 wdog &= ~((1 << 27)|(1 << 26)|(1 << 25)|(1 << 24));
348 /* No monitor bits */
349 wdog &= ~((1 << 16)|(1 << 13)|(1 << 12)|(1 << 11)|(1 << 10)|(1 << 9));
350
351 pci_write_config_dword(pdev, 0xCC, wdog);
352
353 return 0;
354}
355
356/*
357 * Kernel Interfaces
358 */
359
360static const struct file_operations ali_fops = {
361 .owner = THIS_MODULE,
362 .write = ali_write,
363 .unlocked_ioctl = ali_ioctl,
364 .compat_ioctl = compat_ptr_ioctl,
365 .open = ali_open,
366 .release = ali_release,
367};
368
369static struct miscdevice ali_miscdev = {
370 .minor = WATCHDOG_MINOR,
371 .name = "watchdog",
372 .fops = &ali_fops,
373};
374
375static struct notifier_block ali_notifier = {
376 .notifier_call = ali_notify_sys,
377};
378
379/*
380 * watchdog_init - module initialiser
381 *
382 * Scan for a suitable watchdog and if so initialize it. Return an error
383 * if we cannot, the error causes the module to unload
384 */
385
386static int __init watchdog_init(void)
387{
388 int ret;
389
390 /* Check whether or not the hardware watchdog is there */
391 if (ali_find_watchdog() != 0)
392 return -ENODEV;
393
394 /* Check that the timeout value is within it's range;
395 if not reset to the default */
396 if (timeout < 1 || timeout >= 18000) {
397 timeout = WATCHDOG_TIMEOUT;
398 pr_info("timeout value must be 0 < timeout < 18000, using %d\n",
399 timeout);
400 }
401
402 /* Calculate the watchdog's timeout */
403 ali_settimer(timeout);
404
405 ret = register_reboot_notifier(&ali_notifier);
406 if (ret != 0) {
407 pr_err("cannot register reboot notifier (err=%d)\n", ret);
408 goto out;
409 }
410
411 ret = misc_register(&ali_miscdev);
412 if (ret != 0) {
413 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
414 WATCHDOG_MINOR, ret);
415 goto unreg_reboot;
416 }
417
418 pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
419 timeout, nowayout);
420
421out:
422 return ret;
423unreg_reboot:
424 unregister_reboot_notifier(&ali_notifier);
425 goto out;
426}
427
428/*
429 * watchdog_exit - module de-initialiser
430 *
431 * Called while unloading a successfully installed watchdog module.
432 */
433
434static void __exit watchdog_exit(void)
435{
436 /* Stop the timer before we leave */
437 ali_stop();
438
439 /* Deregister */
440 misc_deregister(&ali_miscdev);
441 unregister_reboot_notifier(&ali_notifier);
442 pci_dev_put(ali_pci);
443}
444
445module_init(watchdog_init);
446module_exit(watchdog_exit);
447
448MODULE_AUTHOR("Alan Cox");
449MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver");
450MODULE_LICENSE("GPL");
1/*
2 * Watchdog for the 7101 PMU version found in the ALi M1535 chipsets
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/module.h>
13#include <linux/moduleparam.h>
14#include <linux/types.h>
15#include <linux/miscdevice.h>
16#include <linux/watchdog.h>
17#include <linux/ioport.h>
18#include <linux/notifier.h>
19#include <linux/reboot.h>
20#include <linux/init.h>
21#include <linux/fs.h>
22#include <linux/pci.h>
23#include <linux/uaccess.h>
24#include <linux/io.h>
25
26#define WATCHDOG_NAME "ALi_M1535"
27#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
28
29/* internal variables */
30static unsigned long ali_is_open;
31static char ali_expect_release;
32static struct pci_dev *ali_pci;
33static u32 ali_timeout_bits; /* stores the computed timeout */
34static DEFINE_SPINLOCK(ali_lock); /* Guards the hardware */
35
36/* module parameters */
37static int timeout = WATCHDOG_TIMEOUT;
38module_param(timeout, int, 0);
39MODULE_PARM_DESC(timeout,
40 "Watchdog timeout in seconds. (0 < timeout < 18000, default="
41 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
42
43static bool nowayout = WATCHDOG_NOWAYOUT;
44module_param(nowayout, bool, 0);
45MODULE_PARM_DESC(nowayout,
46 "Watchdog cannot be stopped once started (default="
47 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
48
49/*
50 * ali_start - start watchdog countdown
51 *
52 * Starts the timer running providing the timer has a counter
53 * configuration set.
54 */
55
56static void ali_start(void)
57{
58 u32 val;
59
60 spin_lock(&ali_lock);
61
62 pci_read_config_dword(ali_pci, 0xCC, &val);
63 val &= ~0x3F; /* Mask count */
64 val |= (1 << 25) | ali_timeout_bits;
65 pci_write_config_dword(ali_pci, 0xCC, val);
66
67 spin_unlock(&ali_lock);
68}
69
70/*
71 * ali_stop - stop the timer countdown
72 *
73 * Stop the ALi watchdog countdown
74 */
75
76static void ali_stop(void)
77{
78 u32 val;
79
80 spin_lock(&ali_lock);
81
82 pci_read_config_dword(ali_pci, 0xCC, &val);
83 val &= ~0x3F; /* Mask count to zero (disabled) */
84 val &= ~(1 << 25); /* and for safety mask the reset enable */
85 pci_write_config_dword(ali_pci, 0xCC, val);
86
87 spin_unlock(&ali_lock);
88}
89
90/*
91 * ali_keepalive - send a keepalive to the watchdog
92 *
93 * Send a keepalive to the timer (actually we restart the timer).
94 */
95
96static void ali_keepalive(void)
97{
98 ali_start();
99}
100
101/*
102 * ali_settimer - compute the timer reload value
103 * @t: time in seconds
104 *
105 * Computes the timeout values needed
106 */
107
108static int ali_settimer(int t)
109{
110 if (t < 0)
111 return -EINVAL;
112 else if (t < 60)
113 ali_timeout_bits = t|(1 << 6);
114 else if (t < 3600)
115 ali_timeout_bits = (t / 60)|(1 << 7);
116 else if (t < 18000)
117 ali_timeout_bits = (t / 300)|(1 << 6)|(1 << 7);
118 else
119 return -EINVAL;
120
121 timeout = t;
122 return 0;
123}
124
125/*
126 * /dev/watchdog handling
127 */
128
129/*
130 * ali_write - writes to ALi watchdog
131 * @file: file from VFS
132 * @data: user address of data
133 * @len: length of data
134 * @ppos: pointer to the file offset
135 *
136 * Handle a write to the ALi watchdog. Writing to the file pings
137 * the watchdog and resets it. Writing the magic 'V' sequence allows
138 * the next close to turn off the watchdog.
139 */
140
141static ssize_t ali_write(struct file *file, const char __user *data,
142 size_t len, loff_t *ppos)
143{
144 /* See if we got the magic character 'V' and reload the timer */
145 if (len) {
146 if (!nowayout) {
147 size_t i;
148
149 /* note: just in case someone wrote the
150 magic character five months ago... */
151 ali_expect_release = 0;
152
153 /* scan to see whether or not we got
154 the magic character */
155 for (i = 0; i != len; i++) {
156 char c;
157 if (get_user(c, data + i))
158 return -EFAULT;
159 if (c == 'V')
160 ali_expect_release = 42;
161 }
162 }
163
164 /* someone wrote to us, we should reload the timer */
165 ali_start();
166 }
167 return len;
168}
169
170/*
171 * ali_ioctl - handle watchdog ioctls
172 * @file: VFS file pointer
173 * @cmd: ioctl number
174 * @arg: arguments to the ioctl
175 *
176 * Handle the watchdog ioctls supported by the ALi driver. Really
177 * we want an extension to enable irq ack monitoring and the like
178 */
179
180static long ali_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
181{
182 void __user *argp = (void __user *)arg;
183 int __user *p = argp;
184 static const struct watchdog_info ident = {
185 .options = WDIOF_KEEPALIVEPING |
186 WDIOF_SETTIMEOUT |
187 WDIOF_MAGICCLOSE,
188 .firmware_version = 0,
189 .identity = "ALi M1535 WatchDog Timer",
190 };
191
192 switch (cmd) {
193 case WDIOC_GETSUPPORT:
194 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
195
196 case WDIOC_GETSTATUS:
197 case WDIOC_GETBOOTSTATUS:
198 return put_user(0, p);
199 case WDIOC_SETOPTIONS:
200 {
201 int new_options, retval = -EINVAL;
202
203 if (get_user(new_options, p))
204 return -EFAULT;
205 if (new_options & WDIOS_DISABLECARD) {
206 ali_stop();
207 retval = 0;
208 }
209 if (new_options & WDIOS_ENABLECARD) {
210 ali_start();
211 retval = 0;
212 }
213 return retval;
214 }
215 case WDIOC_KEEPALIVE:
216 ali_keepalive();
217 return 0;
218 case WDIOC_SETTIMEOUT:
219 {
220 int new_timeout;
221 if (get_user(new_timeout, p))
222 return -EFAULT;
223 if (ali_settimer(new_timeout))
224 return -EINVAL;
225 ali_keepalive();
226 }
227 /* fall through */
228 case WDIOC_GETTIMEOUT:
229 return put_user(timeout, p);
230 default:
231 return -ENOTTY;
232 }
233}
234
235/*
236 * ali_open - handle open of ali watchdog
237 * @inode: inode from VFS
238 * @file: file from VFS
239 *
240 * Open the ALi watchdog device. Ensure only one person opens it
241 * at a time. Also start the watchdog running.
242 */
243
244static int ali_open(struct inode *inode, struct file *file)
245{
246 /* /dev/watchdog can only be opened once */
247 if (test_and_set_bit(0, &ali_is_open))
248 return -EBUSY;
249
250 /* Activate */
251 ali_start();
252 return nonseekable_open(inode, file);
253}
254
255/*
256 * ali_release - close an ALi watchdog
257 * @inode: inode from VFS
258 * @file: file from VFS
259 *
260 * Close the ALi watchdog device. Actual shutdown of the timer
261 * only occurs if the magic sequence has been set.
262 */
263
264static int ali_release(struct inode *inode, struct file *file)
265{
266 /*
267 * Shut off the timer.
268 */
269 if (ali_expect_release == 42)
270 ali_stop();
271 else {
272 pr_crit("Unexpected close, not stopping watchdog!\n");
273 ali_keepalive();
274 }
275 clear_bit(0, &ali_is_open);
276 ali_expect_release = 0;
277 return 0;
278}
279
280/*
281 * ali_notify_sys - System down notifier
282 *
283 * Notifier for system down
284 */
285
286
287static int ali_notify_sys(struct notifier_block *this,
288 unsigned long code, void *unused)
289{
290 if (code == SYS_DOWN || code == SYS_HALT)
291 ali_stop(); /* Turn the WDT off */
292 return NOTIFY_DONE;
293}
294
295/*
296 * Data for PCI driver interface
297 *
298 * This data only exists for exporting the supported
299 * PCI ids via MODULE_DEVICE_TABLE. We do not actually
300 * register a pci_driver, because someone else might one day
301 * want to register another driver on the same PCI id.
302 */
303
304static const struct pci_device_id ali_pci_tbl[] __used = {
305 { PCI_VENDOR_ID_AL, 0x1533, PCI_ANY_ID, PCI_ANY_ID,},
306 { PCI_VENDOR_ID_AL, 0x1535, PCI_ANY_ID, PCI_ANY_ID,},
307 { 0, },
308};
309MODULE_DEVICE_TABLE(pci, ali_pci_tbl);
310
311/*
312 * ali_find_watchdog - find a 1535 and 7101
313 *
314 * Scans the PCI hardware for a 1535 series bridge and matching 7101
315 * watchdog device. This may be overtight but it is better to be safe
316 */
317
318static int __init ali_find_watchdog(void)
319{
320 struct pci_dev *pdev;
321 u32 wdog;
322
323 /* Check for a 1533/1535 series bridge */
324 pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1535, NULL);
325 if (pdev == NULL)
326 pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x1533, NULL);
327 if (pdev == NULL)
328 return -ENODEV;
329 pci_dev_put(pdev);
330
331 /* Check for the a 7101 PMU */
332 pdev = pci_get_device(PCI_VENDOR_ID_AL, 0x7101, NULL);
333 if (pdev == NULL)
334 return -ENODEV;
335
336 if (pci_enable_device(pdev)) {
337 pci_dev_put(pdev);
338 return -EIO;
339 }
340
341 ali_pci = pdev;
342
343 /*
344 * Initialize the timer bits
345 */
346 pci_read_config_dword(pdev, 0xCC, &wdog);
347
348 /* Timer bits */
349 wdog &= ~0x3F;
350 /* Issued events */
351 wdog &= ~((1 << 27)|(1 << 26)|(1 << 25)|(1 << 24));
352 /* No monitor bits */
353 wdog &= ~((1 << 16)|(1 << 13)|(1 << 12)|(1 << 11)|(1 << 10)|(1 << 9));
354
355 pci_write_config_dword(pdev, 0xCC, wdog);
356
357 return 0;
358}
359
360/*
361 * Kernel Interfaces
362 */
363
364static const struct file_operations ali_fops = {
365 .owner = THIS_MODULE,
366 .llseek = no_llseek,
367 .write = ali_write,
368 .unlocked_ioctl = ali_ioctl,
369 .open = ali_open,
370 .release = ali_release,
371};
372
373static struct miscdevice ali_miscdev = {
374 .minor = WATCHDOG_MINOR,
375 .name = "watchdog",
376 .fops = &ali_fops,
377};
378
379static struct notifier_block ali_notifier = {
380 .notifier_call = ali_notify_sys,
381};
382
383/*
384 * watchdog_init - module initialiser
385 *
386 * Scan for a suitable watchdog and if so initialize it. Return an error
387 * if we cannot, the error causes the module to unload
388 */
389
390static int __init watchdog_init(void)
391{
392 int ret;
393
394 /* Check whether or not the hardware watchdog is there */
395 if (ali_find_watchdog() != 0)
396 return -ENODEV;
397
398 /* Check that the timeout value is within it's range;
399 if not reset to the default */
400 if (timeout < 1 || timeout >= 18000) {
401 timeout = WATCHDOG_TIMEOUT;
402 pr_info("timeout value must be 0 < timeout < 18000, using %d\n",
403 timeout);
404 }
405
406 /* Calculate the watchdog's timeout */
407 ali_settimer(timeout);
408
409 ret = register_reboot_notifier(&ali_notifier);
410 if (ret != 0) {
411 pr_err("cannot register reboot notifier (err=%d)\n", ret);
412 goto out;
413 }
414
415 ret = misc_register(&ali_miscdev);
416 if (ret != 0) {
417 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
418 WATCHDOG_MINOR, ret);
419 goto unreg_reboot;
420 }
421
422 pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
423 timeout, nowayout);
424
425out:
426 return ret;
427unreg_reboot:
428 unregister_reboot_notifier(&ali_notifier);
429 goto out;
430}
431
432/*
433 * watchdog_exit - module de-initialiser
434 *
435 * Called while unloading a successfully installed watchdog module.
436 */
437
438static void __exit watchdog_exit(void)
439{
440 /* Stop the timer before we leave */
441 ali_stop();
442
443 /* Deregister */
444 misc_deregister(&ali_miscdev);
445 unregister_reboot_notifier(&ali_notifier);
446 pci_dev_put(ali_pci);
447}
448
449module_init(watchdog_init);
450module_exit(watchdog_exit);
451
452MODULE_AUTHOR("Alan Cox");
453MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver");
454MODULE_LICENSE("GPL");