w83977f_wdt.c 12 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
/*
 *	W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip
 *
 *	(c) Copyright 2005  Jose Goncalves <jose.goncalves@inov.pt>
 *
 *      Based on w83877f_wdt.c by Scott Jennings,
 *           and wdt977.c by Woody Suwalski
 *
 *			-----------------------
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 *
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
29 30
#include <linux/uaccess.h>
#include <linux/io.h>
31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

#include <asm/system.h>

#define WATCHDOG_VERSION  "1.00"
#define WATCHDOG_NAME     "W83977F WDT"
#define PFX WATCHDOG_NAME ": "
#define DRIVER_VERSION    WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"

#define IO_INDEX_PORT     0x3F0
#define IO_DATA_PORT      (IO_INDEX_PORT+1)

#define UNLOCK_DATA       0x87
#define LOCK_DATA         0xAA
#define DEVICE_REGISTER   0x07

#define	DEFAULT_TIMEOUT   45		/* default timeout in seconds */

static	int timeout = DEFAULT_TIMEOUT;
static	int timeoutW;			/* timeout in watchdog counter units */
static	unsigned long timer_alive;
static	int testmode;
static	char expect_close;
53
static	DEFINE_SPINLOCK(spinlock);
54 55

module_param(timeout, int, 0);
56 57 58
MODULE_PARM_DESC(timeout,
		"Watchdog timeout in seconds (15..7635), default="
				__MODULE_STRING(DEFAULT_TIMEOUT) ")");
59
module_param(testmode, int, 0);
60
MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
61

62
static int nowayout = WATCHDOG_NOWAYOUT;
63
module_param(nowayout, int, 0);
64 65 66
MODULE_PARM_DESC(nowayout,
		"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
67 68 69 70 71 72 73 74 75 76 77 78

/*
 * Start the watchdog
 */

static int wdt_start(void)
{
	unsigned long flags;

	spin_lock_irqsave(&spinlock, flags);

	/* Unlock the SuperIO chip */
79 80
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
81 82 83 84 85 86 87

	/*
	 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
	 * F2 has the timeout in watchdog counter units.
	 * F3 is set to enable watchdog LED blink at timeout.
	 * F4 is used to just clear the TIMEOUT'ed state (bit 0).
	 */
88 89 90 91 92 93 94 95
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF2, IO_INDEX_PORT);
	outb_p(timeoutW, IO_DATA_PORT);
	outb_p(0xF3, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF4, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);
96 97

	/* Set device Aux2 active */
98 99
	outb_p(0x30, IO_INDEX_PORT);
	outb_p(0x01, IO_DATA_PORT);
100

101
	/*
102 103 104 105 106 107
	 * Select device Aux1 (dev=7) to set GP16 as the watchdog output
	 * (in reg E6) and GP13 as the watchdog LED output (in reg E3).
	 * Map GP16 at pin 119.
	 * In test mode watch the bit 0 on F4 to indicate "triggered" or
	 * check watchdog LED on SBC.
	 */
108 109 110
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x07, IO_DATA_PORT);
	if (!testmode) {
111 112
		unsigned pin_map;

113 114 115
		outb_p(0xE6, IO_INDEX_PORT);
		outb_p(0x0A, IO_DATA_PORT);
		outb_p(0x2C, IO_INDEX_PORT);
116 117 118
		pin_map = inb_p(IO_DATA_PORT);
		pin_map |= 0x10;
		pin_map &= ~(0x20);
119 120
		outb_p(0x2C, IO_INDEX_PORT);
		outb_p(pin_map, IO_DATA_PORT);
121
	}
122 123
	outb_p(0xE3, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
124 125

	/* Set device Aux1 active */
126 127
	outb_p(0x30, IO_INDEX_PORT);
	outb_p(0x01, IO_DATA_PORT);
128 129

	/* Lock the SuperIO chip */
130
	outb_p(LOCK_DATA, IO_INDEX_PORT);
131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149

	spin_unlock_irqrestore(&spinlock, flags);

	printk(KERN_INFO PFX "activated.\n");

	return 0;
}

/*
 * Stop the watchdog
 */

static int wdt_stop(void)
{
	unsigned long flags;

	spin_lock_irqsave(&spinlock, flags);

	/* Unlock the SuperIO chip */
150 151
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
152

153
	/*
154 155 156 157 158
	 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
	 * F2 is reset to its default value (watchdog timer disabled).
	 * F3 is reset to its default state.
	 * F4 clears the TIMEOUT'ed state (bit 0) - back to default.
	 */
159 160 161 162 163 164 165 166 167 168
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF2, IO_INDEX_PORT);
	outb_p(0xFF, IO_DATA_PORT);
	outb_p(0xF3, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);
	outb_p(0xF4, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);
	outb_p(0xF2, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);
169 170

	/*
171
	 * Select device Aux1 (dev=7) to set GP16 (in reg E6) and
172 173
	 * Gp13 (in reg E3) as inputs.
	 */
174 175 176 177 178
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x07, IO_DATA_PORT);
	if (!testmode) {
		outb_p(0xE6, IO_INDEX_PORT);
		outb_p(0x01, IO_DATA_PORT);
179
	}
180 181
	outb_p(0xE3, IO_INDEX_PORT);
	outb_p(0x01, IO_DATA_PORT);
182 183

	/* Lock the SuperIO chip */
184
	outb_p(LOCK_DATA, IO_INDEX_PORT);
185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204

	spin_unlock_irqrestore(&spinlock, flags);

	printk(KERN_INFO PFX "shutdown.\n");

	return 0;
}

/*
 * Send a keepalive ping to the watchdog
 * This is done by simply re-writing the timeout to reg. 0xF2
 */

static int wdt_keepalive(void)
{
	unsigned long flags;

	spin_lock_irqsave(&spinlock, flags);

	/* Unlock the SuperIO chip */
205 206
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
207 208

	/* Select device Aux2 (device=8) to kick watchdog reg F2 */
209 210 211 212
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF2, IO_INDEX_PORT);
	outb_p(timeoutW, IO_DATA_PORT);
213 214

	/* Lock the SuperIO chip */
215
	outb_p(LOCK_DATA, IO_INDEX_PORT);
216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231

	spin_unlock_irqrestore(&spinlock, flags);

	return 0;
}

/*
 * Set the watchdog timeout value
 */

static int wdt_set_timeout(int t)
{
	int tmrval;

	/*
	 * Convert seconds to watchdog counter time units, rounding up.
232
	 * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup
233 234 235 236 237 238 239 240 241 242 243 244 245
	 * value. This information is supplied in the PCM-5335 manual and was
	 * checked by me on a real board. This is a bit strange because W83977f
	 * datasheet says counter unit is in minutes!
	 */
	if (t < 15)
		return -EINVAL;

	tmrval = ((t + 15) + 29) / 30;

	if (tmrval > 255)
		return -EINVAL;

	/*
246
	 * timeout is the timeout in seconds,
247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265
	 * timeoutW is the timeout in watchdog counter units.
	 */
	timeoutW = tmrval;
	timeout = (timeoutW * 30) - 15;
	return 0;
}

/*
 * Get the watchdog status
 */

static int wdt_get_status(int *status)
{
	int new_status;
	unsigned long flags;

	spin_lock_irqsave(&spinlock, flags);

	/* Unlock the SuperIO chip */
266 267
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
268 269

	/* Select device Aux2 (device=8) to read watchdog reg F4 */
270 271 272
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF4, IO_INDEX_PORT);
273 274 275
	new_status = inb_p(IO_DATA_PORT);

	/* Lock the SuperIO chip */
276
	outb_p(LOCK_DATA, IO_INDEX_PORT);
277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294

	spin_unlock_irqrestore(&spinlock, flags);

	*status = 0;
	if (new_status & 1)
		*status |= WDIOF_CARDRESET;

	return 0;
}


/*
 *	/dev/watchdog handling
 */

static int wdt_open(struct inode *inode, struct file *file)
{
	/* If the watchdog is alive we don't need to start it again */
295
	if (test_and_set_bit(0, &timer_alive))
296 297 298 299 300 301 302 303 304 305 306 307 308 309 310
		return -EBUSY;

	if (nowayout)
		__module_get(THIS_MODULE);

	wdt_start();
	return nonseekable_open(inode, file);
}

static int wdt_release(struct inode *inode, struct file *file)
{
	/*
	 * Shut off the timer.
	 * Lock it in if it's a module and we set nowayout
	 */
311
	if (expect_close == 42) {
312 313 314 315
		wdt_stop();
		clear_bit(0, &timer_alive);
	} else {
		wdt_keepalive();
316 317
		printk(KERN_CRIT PFX
			"unexpected close, not stopping watchdog!\n");
318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337
	}
	expect_close = 0;
	return 0;
}

/*
 *      wdt_write:
 *      @file: file handle to the watchdog
 *      @buf: buffer to write (unused as data does not matter here
 *      @count: count of bytes
 *      @ppos: pointer to the position to write. No seeks allowed
 *
 *      A write to a watchdog device is defined as a keepalive signal. Any
 *      write of data will do, as we we don't define content meaning.
 */

static ssize_t wdt_write(struct file *file, const char __user *buf,
			    size_t count, loff_t *ppos)
{
	/* See if we got the magic character 'V' and reload the timer */
338 339
	if (count) {
		if (!nowayout) {
340 341
			size_t ofs;

342 343
			/* note: just in case someone wrote the
			   magic character long ago */
344 345
			expect_close = 0;

346 347 348
			/* scan to see whether or not we got the
			   magic character */
			for (ofs = 0; ofs != count; ofs++) {
349 350 351
				char c;
				if (get_user(c, buf + ofs))
					return -EFAULT;
352
				if (c == 'V')
353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373
					expect_close = 42;
			}
		}

		/* someone wrote to us, we should restart timer */
		wdt_keepalive();
	}
	return count;
}

/*
 *      wdt_ioctl:
 *      @inode: inode of the device
 *      @file: file handle to the device
 *      @cmd: watchdog command
 *      @arg: argument pointer
 *
 *      The watchdog API defines a common set of functions for all watchdogs
 *      according to their available features.
 */

374
static const struct watchdog_info ident = {
375 376 377 378 379
	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
	.firmware_version =	1,
	.identity = WATCHDOG_NAME,
};

380
static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
381 382 383 384 385 386 387 388 389 390 391
{
	int status;
	int new_options, retval = -EINVAL;
	int new_timeout;
	union {
		struct watchdog_info __user *ident;
		int __user *i;
	} uarg;

	uarg.i = (int __user *)arg;

392
	switch (cmd) {
393
	case WDIOC_GETSUPPORT:
394 395
		return copy_to_user(uarg.ident, &ident,
						sizeof(ident)) ? -EFAULT : 0;
396 397 398 399 400 401 402 403 404

	case WDIOC_GETSTATUS:
		wdt_get_status(&status);
		return put_user(status, uarg.i);

	case WDIOC_GETBOOTSTATUS:
		return put_user(0, uarg.i);

	case WDIOC_SETOPTIONS:
405
		if (get_user(new_options, uarg.i))
406 407 408 409 410 411 412 413 414 415 416 417 418 419
			return -EFAULT;

		if (new_options & WDIOS_DISABLECARD) {
			wdt_stop();
			retval = 0;
		}

		if (new_options & WDIOS_ENABLECARD) {
			wdt_start();
			retval = 0;
		}

		return retval;

420 421 422 423
	case WDIOC_KEEPALIVE:
		wdt_keepalive();
		return 0;

424 425 426 427 428
	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, uarg.i))
			return -EFAULT;

		if (wdt_set_timeout(new_timeout))
429
			return -EINVAL;
430 431 432 433 434 435 436

		wdt_keepalive();
		/* Fall */

	case WDIOC_GETTIMEOUT:
		return put_user(timeout, uarg.i);

437 438 439
	default:
		return -ENOTTY;

440 441 442 443 444 445
	}
}

static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
	void *unused)
{
446
	if (code == SYS_DOWN || code == SYS_HALT)
447 448 449 450
		wdt_stop();
	return NOTIFY_DONE;
}

451
static const struct file_operations wdt_fops = {
452 453 454
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= wdt_write,
455
	.unlocked_ioctl	= wdt_ioctl,
456 457 458 459
	.open		= wdt_open,
	.release	= wdt_release,
};

460
static struct miscdevice wdt_miscdev = {
461 462 463 464 465 466 467 468 469 470 471 472 473
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &wdt_fops,
};

static struct notifier_block wdt_notifier = {
	.notifier_call = wdt_notify_sys,
};

static int __init w83977f_wdt_init(void)
{
	int rc;

474
	printk(KERN_INFO PFX DRIVER_VERSION);
475 476

	/*
477
	 * Check that the timeout value is within it's range;
478 479 480 481
	 * if not reset to the default
	 */
	if (wdt_set_timeout(timeout)) {
		wdt_set_timeout(DEFAULT_TIMEOUT);
482 483 484
		printk(KERN_INFO PFX
		    "timeout value must be 15 <= timeout <= 7635, using %d\n",
							DEFAULT_TIMEOUT);
485 486
	}

487
	if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
488 489 490 491 492 493
		printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
			IO_INDEX_PORT);
		rc = -EIO;
		goto err_out;
	}

494
	rc = register_reboot_notifier(&wdt_notifier);
495 496 497
	if (rc) {
		printk(KERN_ERR PFX
			"cannot register reboot notifier (err=%d)\n", rc);
498 499 500
		goto err_out_region;
	}

501
	rc = misc_register(&wdt_miscdev);
502 503 504 505
	if (rc) {
		printk(KERN_ERR PFX
			"cannot register miscdev on minor=%d (err=%d)\n",
						wdt_miscdev.minor, rc);
506
		goto err_out_reboot;
507 508
	}

509 510 511
	printk(KERN_INFO PFX
		"initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
					timeout, nowayout, testmode);
512 513 514

	return 0;

515 516
err_out_reboot:
	unregister_reboot_notifier(&wdt_notifier);
517
err_out_region:
518
	release_region(IO_INDEX_PORT, 2);
519 520 521 522 523 524 525 526 527
err_out:
	return rc;
}

static void __exit w83977f_wdt_exit(void)
{
	wdt_stop();
	misc_deregister(&wdt_miscdev);
	unregister_reboot_notifier(&wdt_notifier);
528
	release_region(IO_INDEX_PORT, 2);
529 530 531 532 533 534 535 536 537
}

module_init(w83977f_wdt_init);
module_exit(w83977f_wdt_exit);

MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);