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 /* Includes */
22 #include <linux/module.h>		/* For module specific items */
23 #include <linux/moduleparam.h>		/* For new moduleparam's */
24 #include <linux/types.h>		/* For standard types (like size_t) */
25 #include <linux/errno.h>		/* For the -ENODEV/... values */
26 #include <linux/kernel.h>		/* For printk/... */
27 #include <linux/miscdevice.h>		/* For MODULE_ALIAS_MISCDEV
28 							(WATCHDOG_MINOR) */
29 #include <linux/watchdog.h>		/* For the watchdog specific items */
30 #include <linux/init.h>			/* For __init/__exit/... */
31 #include <linux/fs.h>			/* For file operations */
32 #include <linux/platform_device.h>	/* For platform_driver framework */
33 #include <linux/ioport.h>		/* For io-port access */
34 #include <linux/spinlock.h>		/* For spin_lock/spin_unlock/... */
35 #include <linux/uaccess.h>		/* For copy_to_user/put_user/... */
36 #include <linux/io.h>			/* For inb/outb/... */
37 
38 /* Module and version information */
39 #define DRV_NAME	"sch311x_wdt"
40 #define PFX		DRV_NAME ": "
41 
42 /* Runtime registers */
43 #define RESGEN			0x1d
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 static unsigned short therm_trip;
72 module_param(therm_trip, ushort, 0);
73 MODULE_PARM_DESC(therm_trip, "Should a ThermTrip trigger the reset generator");
74 
75 #define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */
76 static int timeout = WATCHDOG_TIMEOUT;	/* in seconds */
77 module_param(timeout, int, 0);
78 MODULE_PARM_DESC(timeout,
79 	"Watchdog timeout in seconds. 1<= timeout <=15300, default="
80 		__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
81 
82 static int nowayout = WATCHDOG_NOWAYOUT;
83 module_param(nowayout, int, 0);
84 MODULE_PARM_DESC(nowayout,
85 	"Watchdog cannot be stopped once started (default="
86 		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
87 
88 /*
89  *	Super-IO functions
90  */
91 
92 static inline void sch311x_sio_enter(int sio_config_port)
93 {
94 	outb(0x55, sio_config_port);
95 }
96 
97 static inline void sch311x_sio_exit(int sio_config_port)
98 {
99 	outb(0xaa, sio_config_port);
100 }
101 
102 static inline int sch311x_sio_inb(int sio_config_port, int reg)
103 {
104 	outb(reg, sio_config_port);
105 	return inb(sio_config_port + 1);
106 }
107 
108 static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
109 {
110 	outb(reg, sio_config_port);
111 	outb(val, sio_config_port + 1);
112 }
113 
114 /*
115  *	Watchdog Operations
116  */
117 
118 static void sch311x_wdt_set_timeout(int t)
119 {
120 	unsigned char timeout_unit = 0x80;
121 
122 	/* When new timeout is bigger then 255 seconds, we will use minutes */
123 	if (t > 255) {
124 		timeout_unit = 0;
125 		t /= 60;
126 	}
127 
128 	/* -- Watchdog Timeout --
129 	 * Bit 0-6 (Reserved)
130 	 * Bit 7   WDT Time-out Value Units Select
131 	 *         (0 = Minutes, 1 = Seconds)
132 	 */
133 	outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT);
134 
135 	/* -- Watchdog Timer Time-out Value --
136 	 * Bit 0-7 Binary coded units (0=Disabled, 1..255)
137 	 */
138 	outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL);
139 }
140 
141 static void sch311x_wdt_start(void)
142 {
143 	spin_lock(&sch311x_wdt_data.io_lock);
144 
145 	/* set watchdog's timeout */
146 	sch311x_wdt_set_timeout(timeout);
147 	/* enable the watchdog */
148 	/* -- General Purpose I/O Bit 6.0 --
149 	 * Bit 0,   In/Out: 0 = Output, 1 = Input
150 	 * Bit 1,   Polarity: 0 = No Invert, 1 = Invert
151 	 * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT,
152 	 *                           10 = Either Edge Triggered Intr.4
153 	 * Bit 4-6  (Reserved)
154 	 * Bit 7,   Output Type: 0 = Push Pull Bit, 1 = Open Drain
155 	 */
156 	outb(0x0e, sch311x_wdt_data.runtime_reg + GP60);
157 
158 	spin_unlock(&sch311x_wdt_data.io_lock);
159 
160 }
161 
162 static void sch311x_wdt_stop(void)
163 {
164 	spin_lock(&sch311x_wdt_data.io_lock);
165 
166 	/* stop the watchdog */
167 	outb(0x01, sch311x_wdt_data.runtime_reg + GP60);
168 	/* disable timeout by setting it to 0 */
169 	sch311x_wdt_set_timeout(0);
170 
171 	spin_unlock(&sch311x_wdt_data.io_lock);
172 }
173 
174 static void sch311x_wdt_keepalive(void)
175 {
176 	spin_lock(&sch311x_wdt_data.io_lock);
177 	sch311x_wdt_set_timeout(timeout);
178 	spin_unlock(&sch311x_wdt_data.io_lock);
179 }
180 
181 static int sch311x_wdt_set_heartbeat(int t)
182 {
183 	if (t < 1 || t > (255*60))
184 		return -EINVAL;
185 
186 	/* When new timeout is bigger then 255 seconds,
187 	 * we will round up to minutes (with a max of 255) */
188 	if (t > 255)
189 		t = (((t - 1) / 60) + 1) * 60;
190 
191 	timeout = t;
192 	return 0;
193 }
194 
195 static void sch311x_wdt_get_status(int *status)
196 {
197 	unsigned char new_status;
198 
199 	*status = 0;
200 
201 	spin_lock(&sch311x_wdt_data.io_lock);
202 
203 	/* -- Watchdog timer control --
204 	 * Bit 0   Status Bit: 0 = Timer counting, 1 = Timeout occurred
205 	 * Bit 1   Reserved
206 	 * Bit 2   Force Timeout: 1 = Forces WD timeout event (self-cleaning)
207 	 * Bit 3   P20 Force Timeout enabled:
208 	 *          0 = P20 activity does not generate the WD timeout event
209 	 *          1 = P20 Allows rising edge of P20, from the keyboard
210 	 *              controller, to force the WD timeout event.
211 	 * Bit 4-7 Reserved
212 	 */
213 	new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL);
214 	if (new_status & 0x01)
215 		*status |= WDIOF_CARDRESET;
216 
217 	spin_unlock(&sch311x_wdt_data.io_lock);
218 }
219 
220 /*
221  *	/dev/watchdog handling
222  */
223 
224 static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf,
225 						size_t count, loff_t *ppos)
226 {
227 	if (count) {
228 		if (!nowayout) {
229 			size_t i;
230 
231 			sch311x_wdt_expect_close = 0;
232 
233 			for (i = 0; i != count; i++) {
234 				char c;
235 				if (get_user(c, buf + i))
236 					return -EFAULT;
237 				if (c == 'V')
238 					sch311x_wdt_expect_close = 42;
239 			}
240 		}
241 		sch311x_wdt_keepalive();
242 	}
243 	return count;
244 }
245 
246 static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd,
247 							unsigned long arg)
248 {
249 	int status;
250 	int new_timeout;
251 	void __user *argp = (void __user *)arg;
252 	int __user *p = argp;
253 	static const struct watchdog_info ident = {
254 		.options		= WDIOF_KEEPALIVEPING |
255 					  WDIOF_SETTIMEOUT |
256 					  WDIOF_MAGICCLOSE,
257 		.firmware_version	= 1,
258 		.identity		= DRV_NAME,
259 	};
260 
261 	switch (cmd) {
262 	case WDIOC_GETSUPPORT:
263 		if (copy_to_user(argp, &ident, sizeof(ident)))
264 			return -EFAULT;
265 		break;
266 
267 	case WDIOC_GETSTATUS:
268 	{
269 		sch311x_wdt_get_status(&status);
270 		return put_user(status, p);
271 	}
272 	case WDIOC_GETBOOTSTATUS:
273 		return put_user(sch311x_wdt_data.boot_status, p);
274 
275 	case WDIOC_SETOPTIONS:
276 	{
277 		int options, retval = -EINVAL;
278 
279 		if (get_user(options, p))
280 			return -EFAULT;
281 		if (options & WDIOS_DISABLECARD) {
282 			sch311x_wdt_stop();
283 			retval = 0;
284 		}
285 		if (options & WDIOS_ENABLECARD) {
286 			sch311x_wdt_start();
287 			retval = 0;
288 		}
289 		return retval;
290 	}
291 	case WDIOC_KEEPALIVE:
292 		sch311x_wdt_keepalive();
293 		break;
294 
295 	case WDIOC_SETTIMEOUT:
296 		if (get_user(new_timeout, p))
297 			return -EFAULT;
298 		if (sch311x_wdt_set_heartbeat(new_timeout))
299 			return -EINVAL;
300 		sch311x_wdt_keepalive();
301 		/* Fall */
302 	case WDIOC_GETTIMEOUT:
303 		return put_user(timeout, p);
304 	default:
305 		return -ENOTTY;
306 	}
307 	return 0;
308 }
309 
310 static int sch311x_wdt_open(struct inode *inode, struct file *file)
311 {
312 	if (test_and_set_bit(0, &sch311x_wdt_is_open))
313 		return -EBUSY;
314 	/*
315 	 *	Activate
316 	 */
317 	sch311x_wdt_start();
318 	return nonseekable_open(inode, file);
319 }
320 
321 static int sch311x_wdt_close(struct inode *inode, struct file *file)
322 {
323 	if (sch311x_wdt_expect_close == 42) {
324 		sch311x_wdt_stop();
325 	} else {
326 		printk(KERN_CRIT PFX
327 				"Unexpected close, not stopping watchdog!\n");
328 		sch311x_wdt_keepalive();
329 	}
330 	clear_bit(0, &sch311x_wdt_is_open);
331 	sch311x_wdt_expect_close = 0;
332 	return 0;
333 }
334 
335 /*
336  *	Kernel Interfaces
337  */
338 
339 static const struct file_operations sch311x_wdt_fops = {
340 	.owner		= THIS_MODULE,
341 	.llseek		= no_llseek,
342 	.write		= sch311x_wdt_write,
343 	.unlocked_ioctl	= sch311x_wdt_ioctl,
344 	.open		= sch311x_wdt_open,
345 	.release	= sch311x_wdt_close,
346 };
347 
348 static struct miscdevice sch311x_wdt_miscdev = {
349 	.minor	= WATCHDOG_MINOR,
350 	.name	= "watchdog",
351 	.fops	= &sch311x_wdt_fops,
352 };
353 
354 /*
355  *	Init & exit routines
356  */
357 
358 static int __devinit sch311x_wdt_probe(struct platform_device *pdev)
359 {
360 	struct device *dev = &pdev->dev;
361 	unsigned char val;
362 	int err;
363 
364 	spin_lock_init(&sch311x_wdt_data.io_lock);
365 
366 	if (!request_region(sch311x_wdt_data.runtime_reg + RESGEN, 1,
367 								DRV_NAME)) {
368 		dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
369 			sch311x_wdt_data.runtime_reg + RESGEN,
370 			sch311x_wdt_data.runtime_reg + RESGEN);
371 		err = -EBUSY;
372 		goto exit;
373 	}
374 
375 	if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) {
376 		dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
377 			sch311x_wdt_data.runtime_reg + GP60,
378 			sch311x_wdt_data.runtime_reg + GP60);
379 		err = -EBUSY;
380 		goto exit_release_region;
381 	}
382 
383 	if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4,
384 								DRV_NAME)) {
385 		dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
386 			sch311x_wdt_data.runtime_reg + WDT_TIME_OUT,
387 			sch311x_wdt_data.runtime_reg + WDT_CTRL);
388 		err = -EBUSY;
389 		goto exit_release_region2;
390 	}
391 
392 	/* Make sure that the watchdog is not running */
393 	sch311x_wdt_stop();
394 
395 	/* Disable keyboard and mouse interaction and interrupt */
396 	/* -- Watchdog timer configuration --
397 	 * Bit 0   Reserved
398 	 * Bit 1   Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
399 	 * Bit 2   Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
400 	 * Bit 3   Reserved
401 	 * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
402 	 *            0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
403 	 */
404 	outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG);
405 
406 	/* Check that the heartbeat value is within it's range ;
407 	 * if not reset to the default */
408 	if (sch311x_wdt_set_heartbeat(timeout)) {
409 		sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT);
410 		dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n",
411 			timeout);
412 	}
413 
414 	/* Get status at boot */
415 	sch311x_wdt_get_status(&sch311x_wdt_data.boot_status);
416 
417 	/* enable watchdog */
418 	/* -- Reset Generator --
419 	 * Bit 0   Enable Watchdog Timer Generation: 0* = Enabled, 1 = Disabled
420 	 * Bit 1   Thermtrip Source Select: O* = No Source, 1 = Source
421 	 * Bit 2   WDT2_CTL: WDT input bit
422 	 * Bit 3-7 Reserved
423 	 */
424 	outb(0, sch311x_wdt_data.runtime_reg + RESGEN);
425 	val = therm_trip ? 0x06 : 0x04;
426 	outb(val, sch311x_wdt_data.runtime_reg + RESGEN);
427 
428 	sch311x_wdt_miscdev.parent = dev;
429 
430 	err = misc_register(&sch311x_wdt_miscdev);
431 	if (err != 0) {
432 		dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n",
433 							WATCHDOG_MINOR, err);
434 		goto exit_release_region3;
435 	}
436 
437 	dev_info(dev,
438 		"SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n",
439 		timeout, nowayout);
440 
441 	return 0;
442 
443 exit_release_region3:
444 	release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
445 exit_release_region2:
446 	release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
447 exit_release_region:
448 	release_region(sch311x_wdt_data.runtime_reg + RESGEN, 1);
449 	sch311x_wdt_data.runtime_reg = 0;
450 exit:
451 	return err;
452 }
453 
454 static int __devexit sch311x_wdt_remove(struct platform_device *pdev)
455 {
456 	/* Stop the timer before we leave */
457 	if (!nowayout)
458 		sch311x_wdt_stop();
459 
460 	/* Deregister */
461 	misc_deregister(&sch311x_wdt_miscdev);
462 	release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
463 	release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
464 	release_region(sch311x_wdt_data.runtime_reg + RESGEN, 1);
465 	sch311x_wdt_data.runtime_reg = 0;
466 	return 0;
467 }
468 
469 static void sch311x_wdt_shutdown(struct platform_device *dev)
470 {
471 	/* Turn the WDT off if we have a soft shutdown */
472 	sch311x_wdt_stop();
473 }
474 
475 #define sch311x_wdt_suspend NULL
476 #define sch311x_wdt_resume  NULL
477 
478 static struct platform_driver sch311x_wdt_driver = {
479 	.probe		= sch311x_wdt_probe,
480 	.remove		= __devexit_p(sch311x_wdt_remove),
481 	.shutdown	= sch311x_wdt_shutdown,
482 	.suspend	= sch311x_wdt_suspend,
483 	.resume		= sch311x_wdt_resume,
484 	.driver		= {
485 		.owner = THIS_MODULE,
486 		.name = DRV_NAME,
487 	},
488 };
489 
490 static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
491 {
492 	int err = 0, reg;
493 	unsigned short base_addr;
494 	unsigned char dev_id;
495 
496 	sch311x_sio_enter(sio_config_port);
497 
498 	/* Check device ID. We currently know about:
499 	 * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */
500 	reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20);
501 	if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) {
502 		err = -ENODEV;
503 		goto exit;
504 	}
505 	dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6;
506 
507 	/* Select logical device A (runtime registers) */
508 	sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
509 
510 	/* Check if Logical Device Register is currently active */
511 	if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
512 		printk(KERN_INFO PFX "Seems that LDN 0x0a is not active...\n");
513 
514 	/* Get the base address of the runtime registers */
515 	base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
516 			   sch311x_sio_inb(sio_config_port, 0x61);
517 	if (!base_addr) {
518 		printk(KERN_ERR PFX "Base address not set.\n");
519 		err = -ENODEV;
520 		goto exit;
521 	}
522 	*addr = base_addr;
523 
524 	printk(KERN_INFO PFX "Found an SMSC SCH311%d chip at 0x%04x\n",
525 		dev_id, base_addr);
526 
527 exit:
528 	sch311x_sio_exit(sio_config_port);
529 	return err;
530 }
531 
532 static int __init sch311x_wdt_init(void)
533 {
534 	int err, i, found = 0;
535 	unsigned short addr = 0;
536 
537 	for (i = 0; !found && sch311x_ioports[i]; i++)
538 		if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
539 			found++;
540 
541 	if (!found)
542 		return -ENODEV;
543 
544 	sch311x_wdt_data.runtime_reg = addr;
545 
546 	err = platform_driver_register(&sch311x_wdt_driver);
547 	if (err)
548 		return err;
549 
550 	sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr,
551 								NULL, 0);
552 
553 	if (IS_ERR(sch311x_wdt_pdev)) {
554 		err = PTR_ERR(sch311x_wdt_pdev);
555 		goto unreg_platform_driver;
556 	}
557 
558 	return 0;
559 
560 unreg_platform_driver:
561 	platform_driver_unregister(&sch311x_wdt_driver);
562 	return err;
563 }
564 
565 static void __exit sch311x_wdt_exit(void)
566 {
567 	platform_device_unregister(sch311x_wdt_pdev);
568 	platform_driver_unregister(&sch311x_wdt_driver);
569 }
570 
571 module_init(sch311x_wdt_init);
572 module_exit(sch311x_wdt_exit);
573 
574 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
575 MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver");
576 MODULE_LICENSE("GPL");
577 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
578 
579