1 /*
2 * sch311x_wdt.c - Driver for the SCH311x Super-I/O chips
3 * integrated watchdog.
4 *
5 * (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
13 * provide warranty for any of this software. This material is
14 * provided "AS-IS" and at no charge.
15 */
16
17 /*
18 * Includes, defines, variables, module parameters, ...
19 */
20
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23 /* Includes */
24 #include <linux/module.h> /* For module specific items */
25 #include <linux/moduleparam.h> /* For new moduleparam's */
26 #include <linux/types.h> /* For standard types (like size_t) */
27 #include <linux/errno.h> /* For the -ENODEV/... values */
28 #include <linux/kernel.h> /* For printk/... */
29 #include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV
30 (WATCHDOG_MINOR) */
31 #include <linux/watchdog.h> /* For the watchdog specific items */
32 #include <linux/init.h> /* For __init/__exit/... */
33 #include <linux/fs.h> /* For file operations */
34 #include <linux/platform_device.h> /* For platform_driver framework */
35 #include <linux/ioport.h> /* For io-port access */
36 #include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
37 #include <linux/uaccess.h> /* For copy_to_user/put_user/... */
38 #include <linux/io.h> /* For inb/outb/... */
39
40 /* Module and version information */
41 #define DRV_NAME "sch311x_wdt"
42
43 /* Runtime registers */
44 #define GP60 0x47
45 #define WDT_TIME_OUT 0x65
46 #define WDT_VAL 0x66
47 #define WDT_CFG 0x67
48 #define WDT_CTRL 0x68
49
50 /* internal variables */
51 static unsigned long sch311x_wdt_is_open;
52 static char sch311x_wdt_expect_close;
53 static struct platform_device *sch311x_wdt_pdev;
54
55 static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 };
56
57 static struct { /* The devices private data */
58 /* the Runtime Register base address */
59 unsigned short runtime_reg;
60 /* The card's boot status */
61 int boot_status;
62 /* the lock for io operations */
63 spinlock_t io_lock;
64 } sch311x_wdt_data;
65
66 /* Module load parameters */
67 static unsigned short force_id;
68 module_param(force_id, ushort, 0);
69 MODULE_PARM_DESC(force_id, "Override the detected device ID");
70
71 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
72 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
73 module_param(timeout, int, 0);
74 MODULE_PARM_DESC(timeout,
75 "Watchdog timeout in seconds. 1<= timeout <=15300, default="
76 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
77
78 static bool nowayout = WATCHDOG_NOWAYOUT;
79 module_param(nowayout, bool, 0);
80 MODULE_PARM_DESC(nowayout,
81 "Watchdog cannot be stopped once started (default="
82 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
83
84 /*
85 * Super-IO functions
86 */
87
sch311x_sio_enter(int sio_config_port)88 static inline void sch311x_sio_enter(int sio_config_port)
89 {
90 outb(0x55, sio_config_port);
91 }
92
sch311x_sio_exit(int sio_config_port)93 static inline void sch311x_sio_exit(int sio_config_port)
94 {
95 outb(0xaa, sio_config_port);
96 }
97
sch311x_sio_inb(int sio_config_port,int reg)98 static inline int sch311x_sio_inb(int sio_config_port, int reg)
99 {
100 outb(reg, sio_config_port);
101 return inb(sio_config_port + 1);
102 }
103
sch311x_sio_outb(int sio_config_port,int reg,int val)104 static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
105 {
106 outb(reg, sio_config_port);
107 outb(val, sio_config_port + 1);
108 }
109
110 /*
111 * Watchdog Operations
112 */
113
sch311x_wdt_set_timeout(int t)114 static void sch311x_wdt_set_timeout(int t)
115 {
116 unsigned char timeout_unit = 0x80;
117
118 /* When new timeout is bigger then 255 seconds, we will use minutes */
119 if (t > 255) {
120 timeout_unit = 0;
121 t /= 60;
122 }
123
124 /* -- Watchdog Timeout --
125 * Bit 0-6 (Reserved)
126 * Bit 7 WDT Time-out Value Units Select
127 * (0 = Minutes, 1 = Seconds)
128 */
129 outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT);
130
131 /* -- Watchdog Timer Time-out Value --
132 * Bit 0-7 Binary coded units (0=Disabled, 1..255)
133 */
134 outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL);
135 }
136
sch311x_wdt_start(void)137 static void sch311x_wdt_start(void)
138 {
139 unsigned char t;
140
141 spin_lock(&sch311x_wdt_data.io_lock);
142
143 /* set watchdog's timeout */
144 sch311x_wdt_set_timeout(timeout);
145 /* enable the watchdog */
146 /* -- General Purpose I/O Bit 6.0 --
147 * Bit 0, In/Out: 0 = Output, 1 = Input
148 * Bit 1, Polarity: 0 = No Invert, 1 = Invert
149 * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT,
150 * 10 = Either Edge Triggered Intr.4
151 * Bit 4-6 (Reserved)
152 * Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
153 */
154 t = inb(sch311x_wdt_data.runtime_reg + GP60);
155 outb((t & ~0x0d) | 0x0c, sch311x_wdt_data.runtime_reg + GP60);
156
157 spin_unlock(&sch311x_wdt_data.io_lock);
158
159 }
160
sch311x_wdt_stop(void)161 static void sch311x_wdt_stop(void)
162 {
163 unsigned char t;
164
165 spin_lock(&sch311x_wdt_data.io_lock);
166
167 /* stop the watchdog */
168 t = inb(sch311x_wdt_data.runtime_reg + GP60);
169 outb((t & ~0x0d) | 0x01, sch311x_wdt_data.runtime_reg + GP60);
170 /* disable timeout by setting it to 0 */
171 sch311x_wdt_set_timeout(0);
172
173 spin_unlock(&sch311x_wdt_data.io_lock);
174 }
175
sch311x_wdt_keepalive(void)176 static void sch311x_wdt_keepalive(void)
177 {
178 spin_lock(&sch311x_wdt_data.io_lock);
179 sch311x_wdt_set_timeout(timeout);
180 spin_unlock(&sch311x_wdt_data.io_lock);
181 }
182
sch311x_wdt_set_heartbeat(int t)183 static int sch311x_wdt_set_heartbeat(int t)
184 {
185 if (t < 1 || t > (255*60))
186 return -EINVAL;
187
188 /* When new timeout is bigger then 255 seconds,
189 * we will round up to minutes (with a max of 255) */
190 if (t > 255)
191 t = (((t - 1) / 60) + 1) * 60;
192
193 timeout = t;
194 return 0;
195 }
196
sch311x_wdt_get_status(int * status)197 static void sch311x_wdt_get_status(int *status)
198 {
199 unsigned char new_status;
200
201 *status = 0;
202
203 spin_lock(&sch311x_wdt_data.io_lock);
204
205 /* -- Watchdog timer control --
206 * Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occurred
207 * Bit 1 Reserved
208 * Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning)
209 * Bit 3 P20 Force Timeout enabled:
210 * 0 = P20 activity does not generate the WD timeout event
211 * 1 = P20 Allows rising edge of P20, from the keyboard
212 * controller, to force the WD timeout event.
213 * Bit 4-7 Reserved
214 */
215 new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL);
216 if (new_status & 0x01)
217 *status |= WDIOF_CARDRESET;
218
219 spin_unlock(&sch311x_wdt_data.io_lock);
220 }
221
222 /*
223 * /dev/watchdog handling
224 */
225
sch311x_wdt_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)226 static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf,
227 size_t count, loff_t *ppos)
228 {
229 if (count) {
230 if (!nowayout) {
231 size_t i;
232
233 sch311x_wdt_expect_close = 0;
234
235 for (i = 0; i != count; i++) {
236 char c;
237 if (get_user(c, buf + i))
238 return -EFAULT;
239 if (c == 'V')
240 sch311x_wdt_expect_close = 42;
241 }
242 }
243 sch311x_wdt_keepalive();
244 }
245 return count;
246 }
247
sch311x_wdt_ioctl(struct file * file,unsigned int cmd,unsigned long arg)248 static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd,
249 unsigned long arg)
250 {
251 int status;
252 int new_timeout;
253 void __user *argp = (void __user *)arg;
254 int __user *p = argp;
255 static const struct watchdog_info ident = {
256 .options = WDIOF_KEEPALIVEPING |
257 WDIOF_SETTIMEOUT |
258 WDIOF_MAGICCLOSE,
259 .firmware_version = 1,
260 .identity = DRV_NAME,
261 };
262
263 switch (cmd) {
264 case WDIOC_GETSUPPORT:
265 if (copy_to_user(argp, &ident, sizeof(ident)))
266 return -EFAULT;
267 break;
268
269 case WDIOC_GETSTATUS:
270 {
271 sch311x_wdt_get_status(&status);
272 return put_user(status, p);
273 }
274 case WDIOC_GETBOOTSTATUS:
275 return put_user(sch311x_wdt_data.boot_status, p);
276
277 case WDIOC_SETOPTIONS:
278 {
279 int options, retval = -EINVAL;
280
281 if (get_user(options, p))
282 return -EFAULT;
283 if (options & WDIOS_DISABLECARD) {
284 sch311x_wdt_stop();
285 retval = 0;
286 }
287 if (options & WDIOS_ENABLECARD) {
288 sch311x_wdt_start();
289 retval = 0;
290 }
291 return retval;
292 }
293 case WDIOC_KEEPALIVE:
294 sch311x_wdt_keepalive();
295 break;
296
297 case WDIOC_SETTIMEOUT:
298 if (get_user(new_timeout, p))
299 return -EFAULT;
300 if (sch311x_wdt_set_heartbeat(new_timeout))
301 return -EINVAL;
302 sch311x_wdt_keepalive();
303 /* Fall */
304 case WDIOC_GETTIMEOUT:
305 return put_user(timeout, p);
306 default:
307 return -ENOTTY;
308 }
309 return 0;
310 }
311
sch311x_wdt_open(struct inode * inode,struct file * file)312 static int sch311x_wdt_open(struct inode *inode, struct file *file)
313 {
314 if (test_and_set_bit(0, &sch311x_wdt_is_open))
315 return -EBUSY;
316 /*
317 * Activate
318 */
319 sch311x_wdt_start();
320 return nonseekable_open(inode, file);
321 }
322
sch311x_wdt_close(struct inode * inode,struct file * file)323 static int sch311x_wdt_close(struct inode *inode, struct file *file)
324 {
325 if (sch311x_wdt_expect_close == 42) {
326 sch311x_wdt_stop();
327 } else {
328 pr_crit("Unexpected close, not stopping watchdog!\n");
329 sch311x_wdt_keepalive();
330 }
331 clear_bit(0, &sch311x_wdt_is_open);
332 sch311x_wdt_expect_close = 0;
333 return 0;
334 }
335
336 /*
337 * Kernel Interfaces
338 */
339
340 static const struct file_operations sch311x_wdt_fops = {
341 .owner = THIS_MODULE,
342 .llseek = no_llseek,
343 .write = sch311x_wdt_write,
344 .unlocked_ioctl = sch311x_wdt_ioctl,
345 .open = sch311x_wdt_open,
346 .release = sch311x_wdt_close,
347 };
348
349 static struct miscdevice sch311x_wdt_miscdev = {
350 .minor = WATCHDOG_MINOR,
351 .name = "watchdog",
352 .fops = &sch311x_wdt_fops,
353 };
354
355 /*
356 * Init & exit routines
357 */
358
sch311x_wdt_probe(struct platform_device * pdev)359 static int sch311x_wdt_probe(struct platform_device *pdev)
360 {
361 struct device *dev = &pdev->dev;
362 int err;
363
364 spin_lock_init(&sch311x_wdt_data.io_lock);
365
366 if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) {
367 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
368 sch311x_wdt_data.runtime_reg + GP60,
369 sch311x_wdt_data.runtime_reg + GP60);
370 err = -EBUSY;
371 goto exit;
372 }
373
374 if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4,
375 DRV_NAME)) {
376 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
377 sch311x_wdt_data.runtime_reg + WDT_TIME_OUT,
378 sch311x_wdt_data.runtime_reg + WDT_CTRL);
379 err = -EBUSY;
380 goto exit_release_region;
381 }
382
383 /* Make sure that the watchdog is not running */
384 sch311x_wdt_stop();
385
386 /* Disable keyboard and mouse interaction and interrupt */
387 /* -- Watchdog timer configuration --
388 * Bit 0 Reserved
389 * Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
390 * Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
391 * Bit 3 Reserved
392 * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
393 * 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
394 */
395 outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG);
396
397 /* Check that the heartbeat value is within it's range ;
398 * if not reset to the default */
399 if (sch311x_wdt_set_heartbeat(timeout)) {
400 sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT);
401 dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n",
402 timeout);
403 }
404
405 /* Get status at boot */
406 sch311x_wdt_get_status(&sch311x_wdt_data.boot_status);
407
408 sch311x_wdt_miscdev.parent = dev;
409
410 err = misc_register(&sch311x_wdt_miscdev);
411 if (err != 0) {
412 dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n",
413 WATCHDOG_MINOR, err);
414 goto exit_release_region2;
415 }
416
417 dev_info(dev,
418 "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n",
419 timeout, nowayout);
420
421 return 0;
422
423 exit_release_region2:
424 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
425 exit_release_region:
426 release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
427 sch311x_wdt_data.runtime_reg = 0;
428 exit:
429 return err;
430 }
431
sch311x_wdt_remove(struct platform_device * pdev)432 static int sch311x_wdt_remove(struct platform_device *pdev)
433 {
434 /* Stop the timer before we leave */
435 if (!nowayout)
436 sch311x_wdt_stop();
437
438 /* Deregister */
439 misc_deregister(&sch311x_wdt_miscdev);
440 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
441 release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
442 sch311x_wdt_data.runtime_reg = 0;
443 return 0;
444 }
445
sch311x_wdt_shutdown(struct platform_device * dev)446 static void sch311x_wdt_shutdown(struct platform_device *dev)
447 {
448 /* Turn the WDT off if we have a soft shutdown */
449 sch311x_wdt_stop();
450 }
451
452 static struct platform_driver sch311x_wdt_driver = {
453 .probe = sch311x_wdt_probe,
454 .remove = sch311x_wdt_remove,
455 .shutdown = sch311x_wdt_shutdown,
456 .driver = {
457 .owner = THIS_MODULE,
458 .name = DRV_NAME,
459 },
460 };
461
sch311x_detect(int sio_config_port,unsigned short * addr)462 static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
463 {
464 int err = 0, reg;
465 unsigned short base_addr;
466 unsigned char dev_id;
467
468 sch311x_sio_enter(sio_config_port);
469
470 /* Check device ID. We currently know about:
471 * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */
472 reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20);
473 if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) {
474 err = -ENODEV;
475 goto exit;
476 }
477 dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6;
478
479 /* Select logical device A (runtime registers) */
480 sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
481
482 /* Check if Logical Device Register is currently active */
483 if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
484 pr_info("Seems that LDN 0x0a is not active...\n");
485
486 /* Get the base address of the runtime registers */
487 base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
488 sch311x_sio_inb(sio_config_port, 0x61);
489 if (!base_addr) {
490 pr_err("Base address not set\n");
491 err = -ENODEV;
492 goto exit;
493 }
494 *addr = base_addr;
495
496 pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);
497
498 exit:
499 sch311x_sio_exit(sio_config_port);
500 return err;
501 }
502
sch311x_wdt_init(void)503 static int __init sch311x_wdt_init(void)
504 {
505 int err, i, found = 0;
506 unsigned short addr = 0;
507
508 for (i = 0; !found && sch311x_ioports[i]; i++)
509 if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
510 found++;
511
512 if (!found)
513 return -ENODEV;
514
515 sch311x_wdt_data.runtime_reg = addr;
516
517 err = platform_driver_register(&sch311x_wdt_driver);
518 if (err)
519 return err;
520
521 sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr,
522 NULL, 0);
523
524 if (IS_ERR(sch311x_wdt_pdev)) {
525 err = PTR_ERR(sch311x_wdt_pdev);
526 goto unreg_platform_driver;
527 }
528
529 return 0;
530
531 unreg_platform_driver:
532 platform_driver_unregister(&sch311x_wdt_driver);
533 return err;
534 }
535
sch311x_wdt_exit(void)536 static void __exit sch311x_wdt_exit(void)
537 {
538 platform_device_unregister(sch311x_wdt_pdev);
539 platform_driver_unregister(&sch311x_wdt_driver);
540 }
541
542 module_init(sch311x_wdt_init);
543 module_exit(sch311x_wdt_exit);
544
545 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
546 MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver");
547 MODULE_LICENSE("GPL");
548 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
549
550