1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19
20#include <linux/module.h>
21#include <linux/moduleparam.h>
22#include <linux/types.h>
23#include <linux/errno.h>
24#include <linux/kernel.h>
25#include <linux/miscdevice.h>
26#include <linux/watchdog.h>
27#include <linux/init.h>
28#include <linux/fs.h>
29#include <linux/platform_device.h>
30#include <linux/ioport.h>
31#include <linux/spinlock.h>
32#include <linux/uaccess.h>
33#include <linux/io.h>
34
35
36#define DRV_NAME "sch311x_wdt"
37
38
39#define GP60 0x47
40#define WDT_TIME_OUT 0x65
41#define WDT_VAL 0x66
42#define WDT_CFG 0x67
43#define WDT_CTRL 0x68
44
45
46static unsigned long sch311x_wdt_is_open;
47static char sch311x_wdt_expect_close;
48static struct platform_device *sch311x_wdt_pdev;
49
50static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 };
51
52static struct {
53
54 unsigned short runtime_reg;
55
56 int boot_status;
57
58 spinlock_t io_lock;
59} sch311x_wdt_data;
60
61
62static unsigned short force_id;
63module_param(force_id, ushort, 0);
64MODULE_PARM_DESC(force_id, "Override the detected device ID");
65
66#define WATCHDOG_TIMEOUT 60
67static int timeout = WATCHDOG_TIMEOUT;
68module_param(timeout, int, 0);
69MODULE_PARM_DESC(timeout,
70 "Watchdog timeout in seconds. 1<= timeout <=15300, default="
71 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
72
73static bool nowayout = WATCHDOG_NOWAYOUT;
74module_param(nowayout, bool, 0);
75MODULE_PARM_DESC(nowayout,
76 "Watchdog cannot be stopped once started (default="
77 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
78
79
80
81
82
83static inline void sch311x_sio_enter(int sio_config_port)
84{
85 outb(0x55, sio_config_port);
86}
87
88static inline void sch311x_sio_exit(int sio_config_port)
89{
90 outb(0xaa, sio_config_port);
91}
92
93static inline int sch311x_sio_inb(int sio_config_port, int reg)
94{
95 outb(reg, sio_config_port);
96 return inb(sio_config_port + 1);
97}
98
99static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
100{
101 outb(reg, sio_config_port);
102 outb(val, sio_config_port + 1);
103}
104
105
106
107
108
109static void sch311x_wdt_set_timeout(int t)
110{
111 unsigned char timeout_unit = 0x80;
112
113
114 if (t > 255) {
115 timeout_unit = 0;
116 t /= 60;
117 }
118
119
120
121
122
123
124 outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT);
125
126
127
128
129 outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL);
130}
131
132static void sch311x_wdt_start(void)
133{
134 unsigned char t;
135
136 spin_lock(&sch311x_wdt_data.io_lock);
137
138
139 sch311x_wdt_set_timeout(timeout);
140
141
142
143
144
145
146
147
148
149 t = inb(sch311x_wdt_data.runtime_reg + GP60);
150 outb((t & ~0x0d) | 0x0c, sch311x_wdt_data.runtime_reg + GP60);
151
152 spin_unlock(&sch311x_wdt_data.io_lock);
153
154}
155
156static void sch311x_wdt_stop(void)
157{
158 unsigned char t;
159
160 spin_lock(&sch311x_wdt_data.io_lock);
161
162
163 t = inb(sch311x_wdt_data.runtime_reg + GP60);
164 outb((t & ~0x0d) | 0x01, sch311x_wdt_data.runtime_reg + GP60);
165
166 sch311x_wdt_set_timeout(0);
167
168 spin_unlock(&sch311x_wdt_data.io_lock);
169}
170
171static void sch311x_wdt_keepalive(void)
172{
173 spin_lock(&sch311x_wdt_data.io_lock);
174 sch311x_wdt_set_timeout(timeout);
175 spin_unlock(&sch311x_wdt_data.io_lock);
176}
177
178static int sch311x_wdt_set_heartbeat(int t)
179{
180 if (t < 1 || t > (255*60))
181 return -EINVAL;
182
183
184
185 if (t > 255)
186 t = (((t - 1) / 60) + 1) * 60;
187
188 timeout = t;
189 return 0;
190}
191
192static void sch311x_wdt_get_status(int *status)
193{
194 unsigned char new_status;
195
196 *status = 0;
197
198 spin_lock(&sch311x_wdt_data.io_lock);
199
200
201
202
203
204
205
206
207
208
209
210 new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL);
211 if (new_status & 0x01)
212 *status |= WDIOF_CARDRESET;
213
214 spin_unlock(&sch311x_wdt_data.io_lock);
215}
216
217
218
219
220
221static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf,
222 size_t count, loff_t *ppos)
223{
224 if (count) {
225 if (!nowayout) {
226 size_t i;
227
228 sch311x_wdt_expect_close = 0;
229
230 for (i = 0; i != count; i++) {
231 char c;
232 if (get_user(c, buf + i))
233 return -EFAULT;
234 if (c == 'V')
235 sch311x_wdt_expect_close = 42;
236 }
237 }
238 sch311x_wdt_keepalive();
239 }
240 return count;
241}
242
243static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd,
244 unsigned long arg)
245{
246 int status;
247 int new_timeout;
248 void __user *argp = (void __user *)arg;
249 int __user *p = argp;
250 static const struct watchdog_info ident = {
251 .options = WDIOF_KEEPALIVEPING |
252 WDIOF_SETTIMEOUT |
253 WDIOF_MAGICCLOSE,
254 .firmware_version = 1,
255 .identity = DRV_NAME,
256 };
257
258 switch (cmd) {
259 case WDIOC_GETSUPPORT:
260 if (copy_to_user(argp, &ident, sizeof(ident)))
261 return -EFAULT;
262 break;
263
264 case WDIOC_GETSTATUS:
265 {
266 sch311x_wdt_get_status(&status);
267 return put_user(status, p);
268 }
269 case WDIOC_GETBOOTSTATUS:
270 return put_user(sch311x_wdt_data.boot_status, p);
271
272 case WDIOC_SETOPTIONS:
273 {
274 int options, retval = -EINVAL;
275
276 if (get_user(options, p))
277 return -EFAULT;
278 if (options & WDIOS_DISABLECARD) {
279 sch311x_wdt_stop();
280 retval = 0;
281 }
282 if (options & WDIOS_ENABLECARD) {
283 sch311x_wdt_start();
284 retval = 0;
285 }
286 return retval;
287 }
288 case WDIOC_KEEPALIVE:
289 sch311x_wdt_keepalive();
290 break;
291
292 case WDIOC_SETTIMEOUT:
293 if (get_user(new_timeout, p))
294 return -EFAULT;
295 if (sch311x_wdt_set_heartbeat(new_timeout))
296 return -EINVAL;
297 sch311x_wdt_keepalive();
298 fallthrough;
299 case WDIOC_GETTIMEOUT:
300 return put_user(timeout, p);
301 default:
302 return -ENOTTY;
303 }
304 return 0;
305}
306
307static int sch311x_wdt_open(struct inode *inode, struct file *file)
308{
309 if (test_and_set_bit(0, &sch311x_wdt_is_open))
310 return -EBUSY;
311
312
313
314 sch311x_wdt_start();
315 return stream_open(inode, file);
316}
317
318static int sch311x_wdt_close(struct inode *inode, struct file *file)
319{
320 if (sch311x_wdt_expect_close == 42) {
321 sch311x_wdt_stop();
322 } else {
323 pr_crit("Unexpected close, not stopping watchdog!\n");
324 sch311x_wdt_keepalive();
325 }
326 clear_bit(0, &sch311x_wdt_is_open);
327 sch311x_wdt_expect_close = 0;
328 return 0;
329}
330
331
332
333
334
335static const struct file_operations sch311x_wdt_fops = {
336 .owner = THIS_MODULE,
337 .llseek = no_llseek,
338 .write = sch311x_wdt_write,
339 .unlocked_ioctl = sch311x_wdt_ioctl,
340 .compat_ioctl = compat_ptr_ioctl,
341 .open = sch311x_wdt_open,
342 .release = sch311x_wdt_close,
343};
344
345static struct miscdevice sch311x_wdt_miscdev = {
346 .minor = WATCHDOG_MINOR,
347 .name = "watchdog",
348 .fops = &sch311x_wdt_fops,
349};
350
351
352
353
354
355static int sch311x_wdt_probe(struct platform_device *pdev)
356{
357 struct device *dev = &pdev->dev;
358 int err;
359
360 spin_lock_init(&sch311x_wdt_data.io_lock);
361
362 if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) {
363 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
364 sch311x_wdt_data.runtime_reg + GP60,
365 sch311x_wdt_data.runtime_reg + GP60);
366 err = -EBUSY;
367 goto exit;
368 }
369
370 if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4,
371 DRV_NAME)) {
372 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
373 sch311x_wdt_data.runtime_reg + WDT_TIME_OUT,
374 sch311x_wdt_data.runtime_reg + WDT_CTRL);
375 err = -EBUSY;
376 goto exit_release_region;
377 }
378
379
380 sch311x_wdt_stop();
381
382
383
384
385
386
387
388
389
390
391 outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG);
392
393
394
395 if (sch311x_wdt_set_heartbeat(timeout)) {
396 sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT);
397 dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n",
398 timeout);
399 }
400
401
402 sch311x_wdt_get_status(&sch311x_wdt_data.boot_status);
403
404 sch311x_wdt_miscdev.parent = dev;
405
406 err = misc_register(&sch311x_wdt_miscdev);
407 if (err != 0) {
408 dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n",
409 WATCHDOG_MINOR, err);
410 goto exit_release_region2;
411 }
412
413 dev_info(dev,
414 "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n",
415 timeout, nowayout);
416
417 return 0;
418
419exit_release_region2:
420 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
421exit_release_region:
422 release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
423 sch311x_wdt_data.runtime_reg = 0;
424exit:
425 return err;
426}
427
428static int sch311x_wdt_remove(struct platform_device *pdev)
429{
430
431 if (!nowayout)
432 sch311x_wdt_stop();
433
434
435 misc_deregister(&sch311x_wdt_miscdev);
436 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
437 release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
438 sch311x_wdt_data.runtime_reg = 0;
439 return 0;
440}
441
442static void sch311x_wdt_shutdown(struct platform_device *dev)
443{
444
445 sch311x_wdt_stop();
446}
447
448static struct platform_driver sch311x_wdt_driver = {
449 .probe = sch311x_wdt_probe,
450 .remove = sch311x_wdt_remove,
451 .shutdown = sch311x_wdt_shutdown,
452 .driver = {
453 .name = DRV_NAME,
454 },
455};
456
457static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
458{
459 int err = 0, reg;
460 unsigned short base_addr;
461 unsigned char dev_id;
462
463 sch311x_sio_enter(sio_config_port);
464
465
466
467 reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20);
468 if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) {
469 err = -ENODEV;
470 goto exit;
471 }
472 dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6;
473
474
475 sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
476
477
478 if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
479 pr_info("Seems that LDN 0x0a is not active...\n");
480
481
482 base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
483 sch311x_sio_inb(sio_config_port, 0x61);
484 if (!base_addr) {
485 pr_err("Base address not set\n");
486 err = -ENODEV;
487 goto exit;
488 }
489 *addr = base_addr;
490
491 pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);
492
493exit:
494 sch311x_sio_exit(sio_config_port);
495 return err;
496}
497
498static int __init sch311x_wdt_init(void)
499{
500 int err, i, found = 0;
501 unsigned short addr = 0;
502
503 for (i = 0; !found && sch311x_ioports[i]; i++)
504 if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
505 found++;
506
507 if (!found)
508 return -ENODEV;
509
510 sch311x_wdt_data.runtime_reg = addr;
511
512 err = platform_driver_register(&sch311x_wdt_driver);
513 if (err)
514 return err;
515
516 sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr,
517 NULL, 0);
518
519 if (IS_ERR(sch311x_wdt_pdev)) {
520 err = PTR_ERR(sch311x_wdt_pdev);
521 goto unreg_platform_driver;
522 }
523
524 return 0;
525
526unreg_platform_driver:
527 platform_driver_unregister(&sch311x_wdt_driver);
528 return err;
529}
530
531static void __exit sch311x_wdt_exit(void)
532{
533 platform_device_unregister(sch311x_wdt_pdev);
534 platform_driver_unregister(&sch311x_wdt_driver);
535}
536
537module_init(sch311x_wdt_init);
538module_exit(sch311x_wdt_exit);
539
540MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
541MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver");
542MODULE_LICENSE("GPL");
543