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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
24
25
26static unsigned long ali_is_open;
27static char ali_expect_release;
28static struct pci_dev *ali_pci;
29static u32 ali_timeout_bits;
30static DEFINE_SPINLOCK(ali_lock);
31
32
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
47
48
49
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;
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
68
69
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;
80 val &= ~(1 << 25);
81 pci_write_config_dword(ali_pci, 0xCC, val);
82
83 spin_unlock(&ali_lock);
84}
85
86
87
88
89
90
91
92static void ali_keepalive(void)
93{
94 ali_start();
95}
96
97
98
99
100
101
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
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137static ssize_t ali_write(struct file *file, const char __user *data,
138 size_t len, loff_t *ppos)
139{
140
141 if (len) {
142 if (!nowayout) {
143 size_t i;
144
145
146
147 ali_expect_release = 0;
148
149
150
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
161 ali_start();
162 }
163 return len;
164}
165
166
167
168
169
170
171
172
173
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
233
234
235
236
237
238
239
240static int ali_open(struct inode *inode, struct file *file)
241{
242
243 if (test_and_set_bit(0, &ali_is_open))
244 return -EBUSY;
245
246
247 ali_start();
248 return stream_open(inode, file);
249}
250
251
252
253
254
255
256
257
258
259
260static int ali_release(struct inode *inode, struct file *file)
261{
262
263
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
278
279
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();
288 return NOTIFY_DONE;
289}
290
291
292
293
294
295
296
297
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
309
310
311
312
313
314static int __init ali_find_watchdog(void)
315{
316 struct pci_dev *pdev;
317 u32 wdog;
318
319
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
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
341
342 pci_read_config_dword(pdev, 0xCC, &wdog);
343
344
345 wdog &= ~0x3F;
346
347 wdog &= ~((1 << 27)|(1 << 26)|(1 << 25)|(1 << 24));
348
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
358
359
360static const struct file_operations ali_fops = {
361 .owner = THIS_MODULE,
362 .llseek = no_llseek,
363 .write = ali_write,
364 .unlocked_ioctl = ali_ioctl,
365 .compat_ioctl = compat_ptr_ioctl,
366 .open = ali_open,
367 .release = ali_release,
368};
369
370static struct miscdevice ali_miscdev = {
371 .minor = WATCHDOG_MINOR,
372 .name = "watchdog",
373 .fops = &ali_fops,
374};
375
376static struct notifier_block ali_notifier = {
377 .notifier_call = ali_notify_sys,
378};
379
380
381
382
383
384
385
386
387static int __init watchdog_init(void)
388{
389 int ret;
390
391
392 if (ali_find_watchdog() != 0)
393 return -ENODEV;
394
395
396
397 if (timeout < 1 || timeout >= 18000) {
398 timeout = WATCHDOG_TIMEOUT;
399 pr_info("timeout value must be 0 < timeout < 18000, using %d\n",
400 timeout);
401 }
402
403
404 ali_settimer(timeout);
405
406 ret = register_reboot_notifier(&ali_notifier);
407 if (ret != 0) {
408 pr_err("cannot register reboot notifier (err=%d)\n", ret);
409 goto out;
410 }
411
412 ret = misc_register(&ali_miscdev);
413 if (ret != 0) {
414 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
415 WATCHDOG_MINOR, ret);
416 goto unreg_reboot;
417 }
418
419 pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
420 timeout, nowayout);
421
422out:
423 return ret;
424unreg_reboot:
425 unregister_reboot_notifier(&ali_notifier);
426 goto out;
427}
428
429
430
431
432
433
434
435static void __exit watchdog_exit(void)
436{
437
438 ali_stop();
439
440
441 misc_deregister(&ali_miscdev);
442 unregister_reboot_notifier(&ali_notifier);
443 pci_dev_put(ali_pci);
444}
445
446module_init(watchdog_init);
447module_exit(watchdog_exit);
448
449MODULE_AUTHOR("Alan Cox");
450MODULE_DESCRIPTION("ALi M1535 PMU Watchdog Timer driver");
451MODULE_LICENSE("GPL");
452