xref: /linux/drivers/watchdog/w83627hf_wdt.c (revision 2da68a77) 
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *	w83627hf/thf WDT driver
4  *
5  *	(c) Copyright 2013 Guenter Roeck
6  *		converted to watchdog infrastructure
7  *
8  *	(c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
9  *		added support for W83627THF.
10  *
11  *	(c) Copyright 2003,2007 Pádraig Brady <P@draigBrady.com>
12  *
13  *	Based on advantechwdt.c which is based on wdt.c.
14  *	Original copyright messages:
15  *
16  *	(c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
17  *
18  *	(c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
19  *						All Rights Reserved.
20  *
21  *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
22  *	warranty for any of this software. This material is provided
23  *	"AS-IS" and at no charge.
24  *
25  *	(c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
26  */
27 
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29 
30 #include <linux/module.h>
31 #include <linux/moduleparam.h>
32 #include <linux/types.h>
33 #include <linux/watchdog.h>
34 #include <linux/ioport.h>
35 #include <linux/init.h>
36 #include <linux/io.h>
37 #include <linux/dmi.h>
38 
39 #define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT"
40 #define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */
41 
42 static int wdt_io;
43 static int cr_wdt_timeout;	/* WDT timeout register */
44 static int cr_wdt_control;	/* WDT control register */
45 static int cr_wdt_csr;		/* WDT control & status register */
46 static int wdt_cfg_enter = 0x87;/* key to unlock configuration space */
47 static int wdt_cfg_leave = 0xAA;/* key to lock configuration space */
48 
49 enum chips { w83627hf, w83627s, w83697hf, w83697ug, w83637hf, w83627thf,
50 	     w83687thf, w83627ehf, w83627dhg, w83627uhg, w83667hg, w83627dhg_p,
51 	     w83667hg_b, nct6775, nct6776, nct6779, nct6791, nct6792, nct6793,
52 	     nct6795, nct6796, nct6102, nct6116 };
53 
54 static int timeout;			/* in seconds */
55 module_param(timeout, int, 0);
56 MODULE_PARM_DESC(timeout,
57 		"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
58 				__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
59 
60 static bool nowayout = WATCHDOG_NOWAYOUT;
61 module_param(nowayout, bool, 0);
62 MODULE_PARM_DESC(nowayout,
63 		"Watchdog cannot be stopped once started (default="
64 				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
65 
66 static int early_disable;
67 module_param(early_disable, int, 0);
68 MODULE_PARM_DESC(early_disable, "Disable watchdog at boot time (default=0)");
69 
70 /*
71  *	Kernel methods.
72  */
73 
74 #define WDT_EFER (wdt_io+0)   /* Extended Function Enable Registers */
75 #define WDT_EFIR (wdt_io+0)   /* Extended Function Index Register
76 							(same as EFER) */
77 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
78 
79 #define W83627HF_LD_WDT		0x08
80 
81 #define W83627HF_ID		0x52
82 #define W83627S_ID		0x59
83 #define W83697HF_ID		0x60
84 #define W83697UG_ID		0x68
85 #define W83637HF_ID		0x70
86 #define W83627THF_ID		0x82
87 #define W83687THF_ID		0x85
88 #define W83627EHF_ID		0x88
89 #define W83627DHG_ID		0xa0
90 #define W83627UHG_ID		0xa2
91 #define W83667HG_ID		0xa5
92 #define W83627DHG_P_ID		0xb0
93 #define W83667HG_B_ID		0xb3
94 #define NCT6775_ID		0xb4
95 #define NCT6776_ID		0xc3
96 #define NCT6102_ID		0xc4
97 #define NCT6116_ID		0xd2
98 #define NCT6779_ID		0xc5
99 #define NCT6791_ID		0xc8
100 #define NCT6792_ID		0xc9
101 #define NCT6793_ID		0xd1
102 #define NCT6795_ID		0xd3
103 #define NCT6796_ID		0xd4	/* also NCT9697D, NCT9698D */
104 
105 #define W83627HF_WDT_TIMEOUT	0xf6
106 #define W83697HF_WDT_TIMEOUT	0xf4
107 #define NCT6102D_WDT_TIMEOUT	0xf1
108 
109 #define W83627HF_WDT_CONTROL	0xf5
110 #define W83697HF_WDT_CONTROL	0xf3
111 #define NCT6102D_WDT_CONTROL	0xf0
112 
113 #define W836X7HF_WDT_CSR	0xf7
114 #define NCT6102D_WDT_CSR	0xf2
115 
116 #define WDT_CSR_STATUS		0x10
117 #define WDT_CSR_KBD		0x40
118 #define WDT_CSR_MOUSE		0x80
119 
120 static void superio_outb(int reg, int val)
121 {
122 	outb(reg, WDT_EFER);
123 	outb(val, WDT_EFDR);
124 }
125 
126 static inline int superio_inb(int reg)
127 {
128 	outb(reg, WDT_EFER);
129 	return inb(WDT_EFDR);
130 }
131 
132 static int superio_enter(void)
133 {
134 	if (!request_muxed_region(wdt_io, 2, WATCHDOG_NAME))
135 		return -EBUSY;
136 
137 	outb_p(wdt_cfg_enter, WDT_EFER); /* Enter extended function mode */
138 	outb_p(wdt_cfg_enter, WDT_EFER); /* Again according to manual */
139 
140 	return 0;
141 }
142 
143 static void superio_select(int ld)
144 {
145 	superio_outb(0x07, ld);
146 }
147 
148 static void superio_exit(void)
149 {
150 	outb_p(wdt_cfg_leave, WDT_EFER); /* Leave extended function mode */
151 	release_region(wdt_io, 2);
152 }
153 
154 static int w83627hf_init(struct watchdog_device *wdog, enum chips chip)
155 {
156 	int ret;
157 	unsigned char t;
158 
159 	ret = superio_enter();
160 	if (ret)
161 		return ret;
162 
163 	superio_select(W83627HF_LD_WDT);
164 
165 	/* set CR30 bit 0 to activate GPIO2 */
166 	t = superio_inb(0x30);
167 	if (!(t & 0x01))
168 		superio_outb(0x30, t | 0x01);
169 
170 	switch (chip) {
171 	case w83627hf:
172 	case w83627s:
173 		t = superio_inb(0x2B) & ~0x10;
174 		superio_outb(0x2B, t); /* set GPIO24 to WDT0 */
175 		break;
176 	case w83697hf:
177 		/* Set pin 119 to WDTO# mode (= CR29, WDT0) */
178 		t = superio_inb(0x29) & ~0x60;
179 		t |= 0x20;
180 		superio_outb(0x29, t);
181 		break;
182 	case w83697ug:
183 		/* Set pin 118 to WDTO# mode */
184 		t = superio_inb(0x2b) & ~0x04;
185 		superio_outb(0x2b, t);
186 		break;
187 	case w83627thf:
188 		t = (superio_inb(0x2B) & ~0x08) | 0x04;
189 		superio_outb(0x2B, t); /* set GPIO3 to WDT0 */
190 		break;
191 	case w83627dhg:
192 	case w83627dhg_p:
193 		t = superio_inb(0x2D) & ~0x01; /* PIN77 -> WDT0# */
194 		superio_outb(0x2D, t); /* set GPIO5 to WDT0 */
195 		t = superio_inb(cr_wdt_control);
196 		t |= 0x02;	/* enable the WDTO# output low pulse
197 				 * to the KBRST# pin */
198 		superio_outb(cr_wdt_control, t);
199 		break;
200 	case w83637hf:
201 		break;
202 	case w83687thf:
203 		t = superio_inb(0x2C) & ~0x80; /* PIN47 -> WDT0# */
204 		superio_outb(0x2C, t);
205 		break;
206 	case w83627ehf:
207 	case w83627uhg:
208 	case w83667hg:
209 	case w83667hg_b:
210 	case nct6775:
211 	case nct6776:
212 	case nct6779:
213 	case nct6791:
214 	case nct6792:
215 	case nct6793:
216 	case nct6795:
217 	case nct6796:
218 	case nct6102:
219 	case nct6116:
220 		/*
221 		 * These chips have a fixed WDTO# output pin (W83627UHG),
222 		 * or support more than one WDTO# output pin.
223 		 * Don't touch its configuration, and hope the BIOS
224 		 * does the right thing.
225 		 */
226 		t = superio_inb(cr_wdt_control);
227 		t |= 0x02;	/* enable the WDTO# output low pulse
228 				 * to the KBRST# pin */
229 		superio_outb(cr_wdt_control, t);
230 		break;
231 	default:
232 		break;
233 	}
234 
235 	t = superio_inb(cr_wdt_timeout);
236 	if (t != 0) {
237 		if (early_disable) {
238 			pr_warn("Stopping previously enabled watchdog until userland kicks in\n");
239 			superio_outb(cr_wdt_timeout, 0);
240 		} else {
241 			pr_info("Watchdog already running. Resetting timeout to %d sec\n",
242 				wdog->timeout);
243 			superio_outb(cr_wdt_timeout, wdog->timeout);
244 		}
245 	}
246 
247 	/* set second mode & disable keyboard turning off watchdog */
248 	t = superio_inb(cr_wdt_control) & ~0x0C;
249 	superio_outb(cr_wdt_control, t);
250 
251 	t = superio_inb(cr_wdt_csr);
252 	if (t & WDT_CSR_STATUS)
253 		wdog->bootstatus |= WDIOF_CARDRESET;
254 
255 	/* reset status, disable keyboard & mouse turning off watchdog */
256 	t &= ~(WDT_CSR_STATUS | WDT_CSR_KBD | WDT_CSR_MOUSE);
257 	superio_outb(cr_wdt_csr, t);
258 
259 	superio_exit();
260 
261 	return 0;
262 }
263 
264 static int wdt_set_time(unsigned int timeout)
265 {
266 	int ret;
267 
268 	ret = superio_enter();
269 	if (ret)
270 		return ret;
271 
272 	superio_select(W83627HF_LD_WDT);
273 	superio_outb(cr_wdt_timeout, timeout);
274 	superio_exit();
275 
276 	return 0;
277 }
278 
279 static int wdt_start(struct watchdog_device *wdog)
280 {
281 	return wdt_set_time(wdog->timeout);
282 }
283 
284 static int wdt_stop(struct watchdog_device *wdog)
285 {
286 	return wdt_set_time(0);
287 }
288 
289 static int wdt_set_timeout(struct watchdog_device *wdog, unsigned int timeout)
290 {
291 	wdog->timeout = timeout;
292 
293 	return 0;
294 }
295 
296 static unsigned int wdt_get_time(struct watchdog_device *wdog)
297 {
298 	unsigned int timeleft;
299 	int ret;
300 
301 	ret = superio_enter();
302 	if (ret)
303 		return 0;
304 
305 	superio_select(W83627HF_LD_WDT);
306 	timeleft = superio_inb(cr_wdt_timeout);
307 	superio_exit();
308 
309 	return timeleft;
310 }
311 
312 /*
313  *	Kernel Interfaces
314  */
315 
316 static const struct watchdog_info wdt_info = {
317 	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
318 	.identity = "W83627HF Watchdog",
319 };
320 
321 static const struct watchdog_ops wdt_ops = {
322 	.owner = THIS_MODULE,
323 	.start = wdt_start,
324 	.stop = wdt_stop,
325 	.set_timeout = wdt_set_timeout,
326 	.get_timeleft = wdt_get_time,
327 };
328 
329 static struct watchdog_device wdt_dev = {
330 	.info = &wdt_info,
331 	.ops = &wdt_ops,
332 	.timeout = WATCHDOG_TIMEOUT,
333 	.min_timeout = 1,
334 	.max_timeout = 255,
335 };
336 
337 /*
338  *	The WDT needs to learn about soft shutdowns in order to
339  *	turn the timebomb registers off.
340  */
341 
342 static int wdt_find(int addr)
343 {
344 	u8 val;
345 	int ret;
346 
347 	cr_wdt_timeout = W83627HF_WDT_TIMEOUT;
348 	cr_wdt_control = W83627HF_WDT_CONTROL;
349 	cr_wdt_csr = W836X7HF_WDT_CSR;
350 
351 	ret = superio_enter();
352 	if (ret)
353 		return ret;
354 	superio_select(W83627HF_LD_WDT);
355 	val = superio_inb(0x20);
356 	switch (val) {
357 	case W83627HF_ID:
358 		ret = w83627hf;
359 		break;
360 	case W83627S_ID:
361 		ret = w83627s;
362 		break;
363 	case W83697HF_ID:
364 		ret = w83697hf;
365 		cr_wdt_timeout = W83697HF_WDT_TIMEOUT;
366 		cr_wdt_control = W83697HF_WDT_CONTROL;
367 		break;
368 	case W83697UG_ID:
369 		ret = w83697ug;
370 		cr_wdt_timeout = W83697HF_WDT_TIMEOUT;
371 		cr_wdt_control = W83697HF_WDT_CONTROL;
372 		break;
373 	case W83637HF_ID:
374 		ret = w83637hf;
375 		break;
376 	case W83627THF_ID:
377 		ret = w83627thf;
378 		break;
379 	case W83687THF_ID:
380 		ret = w83687thf;
381 		break;
382 	case W83627EHF_ID:
383 		ret = w83627ehf;
384 		break;
385 	case W83627DHG_ID:
386 		ret = w83627dhg;
387 		break;
388 	case W83627DHG_P_ID:
389 		ret = w83627dhg_p;
390 		break;
391 	case W83627UHG_ID:
392 		ret = w83627uhg;
393 		break;
394 	case W83667HG_ID:
395 		ret = w83667hg;
396 		break;
397 	case W83667HG_B_ID:
398 		ret = w83667hg_b;
399 		break;
400 	case NCT6775_ID:
401 		ret = nct6775;
402 		break;
403 	case NCT6776_ID:
404 		ret = nct6776;
405 		break;
406 	case NCT6779_ID:
407 		ret = nct6779;
408 		break;
409 	case NCT6791_ID:
410 		ret = nct6791;
411 		break;
412 	case NCT6792_ID:
413 		ret = nct6792;
414 		break;
415 	case NCT6793_ID:
416 		ret = nct6793;
417 		break;
418 	case NCT6795_ID:
419 		ret = nct6795;
420 		break;
421 	case NCT6796_ID:
422 		ret = nct6796;
423 		break;
424 	case NCT6102_ID:
425 		ret = nct6102;
426 		cr_wdt_timeout = NCT6102D_WDT_TIMEOUT;
427 		cr_wdt_control = NCT6102D_WDT_CONTROL;
428 		cr_wdt_csr = NCT6102D_WDT_CSR;
429 		break;
430 	case NCT6116_ID:
431 		ret = nct6116;
432 		cr_wdt_timeout = NCT6102D_WDT_TIMEOUT;
433 		cr_wdt_control = NCT6102D_WDT_CONTROL;
434 		cr_wdt_csr = NCT6102D_WDT_CSR;
435 		break;
436 	case 0xff:
437 		ret = -ENODEV;
438 		break;
439 	default:
440 		ret = -ENODEV;
441 		pr_err("Unsupported chip ID: 0x%02x\n", val);
442 		break;
443 	}
444 	superio_exit();
445 	return ret;
446 }
447 
448 /*
449  * On some systems, the NCT6791D comes with a companion chip and the
450  * watchdog function is in this companion chip. We must use a different
451  * unlocking sequence to access the companion chip.
452  */
453 static int __init wdt_use_alt_key(const struct dmi_system_id *d)
454 {
455 	wdt_cfg_enter = 0x88;
456 	wdt_cfg_leave = 0xBB;
457 
458 	return 0;
459 }
460 
461 static const struct dmi_system_id wdt_dmi_table[] __initconst = {
462 	{
463 		.matches = {
464 			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "INVES"),
465 			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "CTS"),
466 			DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "INVES"),
467 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "SHARKBAY"),
468 		},
469 		.callback = wdt_use_alt_key,
470 	},
471 	{}
472 };
473 
474 static int __init wdt_init(void)
475 {
476 	int ret;
477 	int chip;
478 	static const char * const chip_name[] = {
479 		"W83627HF",
480 		"W83627S",
481 		"W83697HF",
482 		"W83697UG",
483 		"W83637HF",
484 		"W83627THF",
485 		"W83687THF",
486 		"W83627EHF",
487 		"W83627DHG",
488 		"W83627UHG",
489 		"W83667HG",
490 		"W83667DHG-P",
491 		"W83667HG-B",
492 		"NCT6775",
493 		"NCT6776",
494 		"NCT6779",
495 		"NCT6791",
496 		"NCT6792",
497 		"NCT6793",
498 		"NCT6795",
499 		"NCT6796",
500 		"NCT6102",
501 		"NCT6116",
502 	};
503 
504 	/* Apply system-specific quirks */
505 	dmi_check_system(wdt_dmi_table);
506 
507 	wdt_io = 0x2e;
508 	chip = wdt_find(0x2e);
509 	if (chip < 0) {
510 		wdt_io = 0x4e;
511 		chip = wdt_find(0x4e);
512 		if (chip < 0)
513 			return chip;
514 	}
515 
516 	pr_info("WDT driver for %s Super I/O chip initialising\n",
517 		chip_name[chip]);
518 
519 	watchdog_init_timeout(&wdt_dev, timeout, NULL);
520 	watchdog_set_nowayout(&wdt_dev, nowayout);
521 	watchdog_stop_on_reboot(&wdt_dev);
522 
523 	ret = w83627hf_init(&wdt_dev, chip);
524 	if (ret) {
525 		pr_err("failed to initialize watchdog (err=%d)\n", ret);
526 		return ret;
527 	}
528 
529 	ret = watchdog_register_device(&wdt_dev);
530 	if (ret)
531 		return ret;
532 
533 	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
534 		wdt_dev.timeout, nowayout);
535 
536 	return ret;
537 }
538 
539 static void __exit wdt_exit(void)
540 {
541 	watchdog_unregister_device(&wdt_dev);
542 }
543 
544 module_init(wdt_init);
545 module_exit(wdt_exit);
546 
547 MODULE_LICENSE("GPL");
548 MODULE_AUTHOR("Pádraig  Brady <P@draigBrady.com>");
549 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
550