xref: /openbmc/linux/drivers/watchdog/pcwd.c (revision 9ac8d3fb)
1 /*
2  * PC Watchdog Driver
3  * by Ken Hollis (khollis@bitgate.com)
4  *
5  * Permission granted from Simon Machell (smachell@berkprod.com)
6  * Written for the Linux Kernel, and GPLed by Ken Hollis
7  *
8  * 960107	Added request_region routines, modulized the whole thing.
9  * 960108	Fixed end-of-file pointer (Thanks to Dan Hollis), added
10  *		WD_TIMEOUT define.
11  * 960216	Added eof marker on the file, and changed verbose messages.
12  * 960716	Made functional and cosmetic changes to the source for
13  *		inclusion in Linux 2.0.x kernels, thanks to Alan Cox.
14  * 960717	Removed read/seek routines, replaced with ioctl.  Also, added
15  *		check_region command due to Alan's suggestion.
16  * 960821	Made changes to compile in newer 2.0.x kernels.  Added
17  *		"cold reboot sense" entry.
18  * 960825	Made a few changes to code, deleted some defines and made
19  *		typedefs to replace them.  Made heartbeat reset only available
20  *		via ioctl, and removed the write routine.
21  * 960828	Added new items for PC Watchdog Rev.C card.
22  * 960829	Changed around all of the IOCTLs, added new features,
23  *		added watchdog disable/re-enable routines.  Added firmware
24  *		version reporting.  Added read routine for temperature.
25  *		Removed some extra defines, added an autodetect Revision
26  *		routine.
27  * 961006       Revised some documentation, fixed some cosmetic bugs.  Made
28  *              drivers to panic the system if it's overheating at bootup.
29  * 961118	Changed some verbiage on some of the output, tidied up
30  *		code bits, and added compatibility to 2.1.x.
31  * 970912       Enabled board on open and disable on close.
32  * 971107	Took account of recent VFS changes (broke read).
33  * 971210       Disable board on initialisation in case board already ticking.
34  * 971222       Changed open/close for temperature handling
35  *              Michael Meskes <meskes@debian.org>.
36  * 980112       Used minor numbers from include/linux/miscdevice.h
37  * 990403       Clear reset status after reading control status register in
38  *              pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]
39  * 990605	Made changes to code to support Firmware 1.22a, added
40  *		fairly useless proc entry.
41  * 990610	removed said useless proc code for the merge <alan>
42  * 000403	Removed last traces of proc code. <davej>
43  * 011214	Added nowayout module option to override
44  *		CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
45  *              Added timeout module option to override default
46  */
47 
48 /*
49  *	A bells and whistles driver is available from http://www.pcwd.de/
50  *	More info available at http://www.berkprod.com/ or
51  *	http://www.pcwatchdog.com/
52  */
53 
54 #include <linux/module.h>	/* For module specific items */
55 #include <linux/moduleparam.h>	/* For new moduleparam's */
56 #include <linux/types.h>	/* For standard types (like size_t) */
57 #include <linux/errno.h>	/* For the -ENODEV/... values */
58 #include <linux/kernel.h>	/* For printk/panic/... */
59 #include <linux/delay.h>	/* For mdelay function */
60 #include <linux/timer.h>	/* For timer related operations */
61 #include <linux/jiffies.h>	/* For jiffies stuff */
62 #include <linux/miscdevice.h>	/* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
63 #include <linux/watchdog.h>	/* For the watchdog specific items */
64 #include <linux/reboot.h>	/* For kernel_power_off() */
65 #include <linux/init.h>		/* For __init/__exit/... */
66 #include <linux/fs.h>		/* For file operations */
67 #include <linux/isa.h>		/* For isa devices */
68 #include <linux/ioport.h>	/* For io-port access */
69 #include <linux/spinlock.h>	/* For spin_lock/spin_unlock/... */
70 #include <linux/uaccess.h>	/* For copy_to_user/put_user/... */
71 #include <linux/io.h>		/* For inb/outb/... */
72 
73 /* Module and version information */
74 #define WATCHDOG_VERSION "1.20"
75 #define WATCHDOG_DATE "18 Feb 2007"
76 #define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
77 #define WATCHDOG_NAME "pcwd"
78 #define PFX WATCHDOG_NAME ": "
79 #define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION " (" WATCHDOG_DATE ")\n"
80 #define WD_VER WATCHDOG_VERSION " (" WATCHDOG_DATE ")"
81 
82 /*
83  * It should be noted that PCWD_REVISION_B was removed because A and B
84  * are essentially the same types of card, with the exception that B
85  * has temperature reporting.  Since I didn't receive a Rev.B card,
86  * the Rev.B card is not supported.  (It's a good thing too, as they
87  * are no longer in production.)
88  */
89 #define	PCWD_REVISION_A		1
90 #define	PCWD_REVISION_C		2
91 
92 /*
93  * These are the auto-probe addresses available.
94  *
95  * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
96  * Revision A has an address range of 2 addresses, while Revision C has 4.
97  */
98 #define PCWD_ISA_NR_CARDS	3
99 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
100 
101 /*
102  * These are the defines that describe the control status bits for the
103  * PCI-PC Watchdog card.
104 */
105 /* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
106 #define WD_WDRST		0x01	/* Previously reset state */
107 #define WD_T110			0x02	/* Temperature overheat sense */
108 #define WD_HRTBT		0x04	/* Heartbeat sense */
109 #define WD_RLY2			0x08	/* External relay triggered */
110 #define WD_SRLY2		0x80	/* Software external relay triggered */
111 /* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
112 #define WD_REVC_WTRP		0x01	/* Watchdog Trip status */
113 #define WD_REVC_HRBT		0x02	/* Watchdog Heartbeat */
114 #define WD_REVC_TTRP		0x04	/* Temperature Trip status */
115 #define WD_REVC_RL2A		0x08	/* Relay 2 activated by
116 							on-board processor */
117 #define WD_REVC_RL1A		0x10	/* Relay 1 active */
118 #define WD_REVC_R2DS		0x40	/* Relay 2 disable */
119 #define WD_REVC_RLY2		0x80	/* Relay 2 activated? */
120 /* Port 2 : Control Status #2 */
121 #define WD_WDIS			0x10	/* Watchdog Disabled */
122 #define WD_ENTP			0x20	/* Watchdog Enable Temperature Trip */
123 #define WD_SSEL			0x40	/* Watchdog Switch Select
124 							(1:SW1 <-> 0:SW2) */
125 #define WD_WCMD			0x80	/* Watchdog Command Mode */
126 
127 /* max. time we give an ISA watchdog card to process a command */
128 /* 500ms for each 4 bit response (according to spec.) */
129 #define ISA_COMMAND_TIMEOUT     1000
130 
131 /* Watchdog's internal commands */
132 #define CMD_ISA_IDLE			0x00
133 #define CMD_ISA_VERSION_INTEGER		0x01
134 #define CMD_ISA_VERSION_TENTH		0x02
135 #define CMD_ISA_VERSION_HUNDRETH	0x03
136 #define CMD_ISA_VERSION_MINOR		0x04
137 #define CMD_ISA_SWITCH_SETTINGS		0x05
138 #define CMD_ISA_RESET_PC		0x06
139 #define CMD_ISA_ARM_0			0x07
140 #define CMD_ISA_ARM_30			0x08
141 #define CMD_ISA_ARM_60			0x09
142 #define CMD_ISA_DELAY_TIME_2SECS	0x0A
143 #define CMD_ISA_DELAY_TIME_4SECS	0x0B
144 #define CMD_ISA_DELAY_TIME_8SECS	0x0C
145 #define CMD_ISA_RESET_RELAYS		0x0D
146 
147 /* Watchdog's Dip Switch heartbeat values */
148 static const int heartbeat_tbl[] = {
149 	20,	/* OFF-OFF-OFF	= 20 Sec  */
150 	40,	/* OFF-OFF-ON	= 40 Sec  */
151 	60,	/* OFF-ON-OFF	=  1 Min  */
152 	300,	/* OFF-ON-ON	=  5 Min  */
153 	600,	/* ON-OFF-OFF	= 10 Min  */
154 	1800,	/* ON-OFF-ON	= 30 Min  */
155 	3600,	/* ON-ON-OFF	=  1 Hour */
156 	7200,	/* ON-ON-ON	=  2 hour */
157 };
158 
159 /*
160  * We are using an kernel timer to do the pinging of the watchdog
161  * every ~500ms. We try to set the internal heartbeat of the
162  * watchdog to 2 ms.
163  */
164 
165 #define WDT_INTERVAL (HZ/2+1)
166 
167 /* We can only use 1 card due to the /dev/watchdog restriction */
168 static int cards_found;
169 
170 /* internal variables */
171 static unsigned long open_allowed;
172 static char expect_close;
173 static int temp_panic;
174 
175 /* this is private data for each ISA-PC watchdog card */
176 static struct {
177 	char fw_ver_str[6];		/* The cards firmware version */
178 	int revision;			/* The card's revision */
179 	int supports_temp;		/* Whether or not the card has
180 						a temperature device */
181 	int command_mode;		/* Whether or not the card is in
182 						command mode */
183 	int boot_status;		/* The card's boot status */
184 	int io_addr;			/* The cards I/O address */
185 	spinlock_t io_lock;		/* the lock for io operations */
186 	struct timer_list timer;	/* The timer that pings the watchdog */
187 	unsigned long next_heartbeat;	/* the next_heartbeat for the timer */
188 } pcwd_private;
189 
190 /* module parameters */
191 #define QUIET	0	/* Default */
192 #define VERBOSE	1	/* Verbose */
193 #define DEBUG	2	/* print fancy stuff too */
194 static int debug = QUIET;
195 module_param(debug, int, 0);
196 MODULE_PARM_DESC(debug,
197 		"Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
198 
199 /* default heartbeat = delay-time from dip-switches */
200 #define WATCHDOG_HEARTBEAT 0
201 static int heartbeat = WATCHDOG_HEARTBEAT;
202 module_param(heartbeat, int, 0);
203 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2 <= heartbeat <= 7200 or 0=delay-time from dip-switches, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
204 
205 static int nowayout = WATCHDOG_NOWAYOUT;
206 module_param(nowayout, int, 0);
207 MODULE_PARM_DESC(nowayout,
208 		"Watchdog cannot be stopped once started (default="
209 				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
210 
211 /*
212  *	Internal functions
213  */
214 
215 static int send_isa_command(int cmd)
216 {
217 	int i;
218 	int control_status;
219 	int port0, last_port0;	/* Double read for stabilising */
220 
221 	if (debug >= DEBUG)
222 		printk(KERN_DEBUG PFX "sending following data cmd=0x%02x\n",
223 			cmd);
224 
225 	/* The WCMD bit must be 1 and the command is only 4 bits in size */
226 	control_status = (cmd & 0x0F) | WD_WCMD;
227 	outb_p(control_status, pcwd_private.io_addr + 2);
228 	udelay(ISA_COMMAND_TIMEOUT);
229 
230 	port0 = inb_p(pcwd_private.io_addr);
231 	for (i = 0; i < 25; ++i) {
232 		last_port0 = port0;
233 		port0 = inb_p(pcwd_private.io_addr);
234 
235 		if (port0 == last_port0)
236 			break;	/* Data is stable */
237 
238 		udelay(250);
239 	}
240 
241 	if (debug >= DEBUG)
242 		printk(KERN_DEBUG PFX "received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
243 			cmd, port0, last_port0);
244 
245 	return port0;
246 }
247 
248 static int set_command_mode(void)
249 {
250 	int i, found = 0, count = 0;
251 
252 	/* Set the card into command mode */
253 	spin_lock(&pcwd_private.io_lock);
254 	while ((!found) && (count < 3)) {
255 		i = send_isa_command(CMD_ISA_IDLE);
256 
257 		if (i == 0x00)
258 			found = 1;
259 		else if (i == 0xF3) {
260 			/* Card does not like what we've done to it */
261 			outb_p(0x00, pcwd_private.io_addr + 2);
262 			udelay(1200);	/* Spec says wait 1ms */
263 			outb_p(0x00, pcwd_private.io_addr + 2);
264 			udelay(ISA_COMMAND_TIMEOUT);
265 		}
266 		count++;
267 	}
268 	spin_unlock(&pcwd_private.io_lock);
269 	pcwd_private.command_mode = found;
270 
271 	if (debug >= DEBUG)
272 		printk(KERN_DEBUG PFX "command_mode=%d\n",
273 				pcwd_private.command_mode);
274 
275 	return found;
276 }
277 
278 static void unset_command_mode(void)
279 {
280 	/* Set the card into normal mode */
281 	spin_lock(&pcwd_private.io_lock);
282 	outb_p(0x00, pcwd_private.io_addr + 2);
283 	udelay(ISA_COMMAND_TIMEOUT);
284 	spin_unlock(&pcwd_private.io_lock);
285 
286 	pcwd_private.command_mode = 0;
287 
288 	if (debug >= DEBUG)
289 		printk(KERN_DEBUG PFX "command_mode=%d\n",
290 				pcwd_private.command_mode);
291 }
292 
293 static inline void pcwd_check_temperature_support(void)
294 {
295 	if (inb(pcwd_private.io_addr) != 0xF0)
296 		pcwd_private.supports_temp = 1;
297 }
298 
299 static inline void pcwd_get_firmware(void)
300 {
301 	int one, ten, hund, minor;
302 
303 	strcpy(pcwd_private.fw_ver_str, "ERROR");
304 
305 	if (set_command_mode()) {
306 		one = send_isa_command(CMD_ISA_VERSION_INTEGER);
307 		ten = send_isa_command(CMD_ISA_VERSION_TENTH);
308 		hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
309 		minor = send_isa_command(CMD_ISA_VERSION_MINOR);
310 		sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c",
311 					one, ten, hund, minor);
312 	}
313 	unset_command_mode();
314 
315 	return;
316 }
317 
318 static inline int pcwd_get_option_switches(void)
319 {
320 	int option_switches = 0;
321 
322 	if (set_command_mode()) {
323 		/* Get switch settings */
324 		option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
325 	}
326 
327 	unset_command_mode();
328 	return option_switches;
329 }
330 
331 static void pcwd_show_card_info(void)
332 {
333 	int option_switches;
334 
335 	/* Get some extra info from the hardware (in command/debug/diag mode) */
336 	if (pcwd_private.revision == PCWD_REVISION_A)
337 		printk(KERN_INFO PFX
338 			"ISA-PC Watchdog (REV.A) detected at port 0x%04x\n",
339 							pcwd_private.io_addr);
340 	else if (pcwd_private.revision == PCWD_REVISION_C) {
341 		pcwd_get_firmware();
342 		printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
343 			pcwd_private.io_addr, pcwd_private.fw_ver_str);
344 		option_switches = pcwd_get_option_switches();
345 		printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
346 			option_switches,
347 			((option_switches & 0x10) ? "ON" : "OFF"),
348 			((option_switches & 0x08) ? "ON" : "OFF"));
349 
350 		/* Reprogram internal heartbeat to 2 seconds */
351 		if (set_command_mode()) {
352 			send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
353 			unset_command_mode();
354 		}
355 	}
356 
357 	if (pcwd_private.supports_temp)
358 		printk(KERN_INFO PFX "Temperature Option Detected\n");
359 
360 	if (pcwd_private.boot_status & WDIOF_CARDRESET)
361 		printk(KERN_INFO PFX "Previous reboot was caused by the card\n");
362 
363 	if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
364 		printk(KERN_EMERG PFX
365 			"Card senses a CPU Overheat. Panicking!\n");
366 		printk(KERN_EMERG PFX
367 			"CPU Overheat\n");
368 	}
369 
370 	if (pcwd_private.boot_status == 0)
371 		printk(KERN_INFO PFX
372 			"No previous trip detected - Cold boot or reset\n");
373 }
374 
375 static void pcwd_timer_ping(unsigned long data)
376 {
377 	int wdrst_stat;
378 
379 	/* If we got a heartbeat pulse within the WDT_INTERVAL
380 	 * we agree to ping the WDT */
381 	if (time_before(jiffies, pcwd_private.next_heartbeat)) {
382 		/* Ping the watchdog */
383 		spin_lock(&pcwd_private.io_lock);
384 		if (pcwd_private.revision == PCWD_REVISION_A) {
385 			/*  Rev A cards are reset by setting the
386 			    WD_WDRST bit in register 1 */
387 			wdrst_stat = inb_p(pcwd_private.io_addr);
388 			wdrst_stat &= 0x0F;
389 			wdrst_stat |= WD_WDRST;
390 
391 			outb_p(wdrst_stat, pcwd_private.io_addr + 1);
392 		} else {
393 			/* Re-trigger watchdog by writing to port 0 */
394 			outb_p(0x00, pcwd_private.io_addr);
395 		}
396 
397 		/* Re-set the timer interval */
398 		mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
399 
400 		spin_unlock(&pcwd_private.io_lock);
401 	} else {
402 		printk(KERN_WARNING PFX
403 			"Heartbeat lost! Will not ping the watchdog\n");
404 	}
405 }
406 
407 static int pcwd_start(void)
408 {
409 	int stat_reg;
410 
411 	pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
412 
413 	/* Start the timer */
414 	mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
415 
416 	/* Enable the port */
417 	if (pcwd_private.revision == PCWD_REVISION_C) {
418 		spin_lock(&pcwd_private.io_lock);
419 		outb_p(0x00, pcwd_private.io_addr + 3);
420 		udelay(ISA_COMMAND_TIMEOUT);
421 		stat_reg = inb_p(pcwd_private.io_addr + 2);
422 		spin_unlock(&pcwd_private.io_lock);
423 		if (stat_reg & WD_WDIS) {
424 			printk(KERN_INFO PFX "Could not start watchdog\n");
425 			return -EIO;
426 		}
427 	}
428 
429 	if (debug >= VERBOSE)
430 		printk(KERN_DEBUG PFX "Watchdog started\n");
431 
432 	return 0;
433 }
434 
435 static int pcwd_stop(void)
436 {
437 	int stat_reg;
438 
439 	/* Stop the timer */
440 	del_timer(&pcwd_private.timer);
441 
442 	/*  Disable the board  */
443 	if (pcwd_private.revision == PCWD_REVISION_C) {
444 		spin_lock(&pcwd_private.io_lock);
445 		outb_p(0xA5, pcwd_private.io_addr + 3);
446 		udelay(ISA_COMMAND_TIMEOUT);
447 		outb_p(0xA5, pcwd_private.io_addr + 3);
448 		udelay(ISA_COMMAND_TIMEOUT);
449 		stat_reg = inb_p(pcwd_private.io_addr + 2);
450 		spin_unlock(&pcwd_private.io_lock);
451 		if ((stat_reg & WD_WDIS) == 0) {
452 			printk(KERN_INFO PFX "Could not stop watchdog\n");
453 			return -EIO;
454 		}
455 	}
456 
457 	if (debug >= VERBOSE)
458 		printk(KERN_DEBUG PFX "Watchdog stopped\n");
459 
460 	return 0;
461 }
462 
463 static int pcwd_keepalive(void)
464 {
465 	/* user land ping */
466 	pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
467 
468 	if (debug >= DEBUG)
469 		printk(KERN_DEBUG PFX "Watchdog keepalive signal send\n");
470 
471 	return 0;
472 }
473 
474 static int pcwd_set_heartbeat(int t)
475 {
476 	if (t < 2 || t > 7200) /* arbitrary upper limit */
477 		return -EINVAL;
478 
479 	heartbeat = t;
480 
481 	if (debug >= VERBOSE)
482 		printk(KERN_DEBUG PFX "New heartbeat: %d\n",
483 		       heartbeat);
484 
485 	return 0;
486 }
487 
488 static int pcwd_get_status(int *status)
489 {
490 	int control_status;
491 
492 	*status = 0;
493 	spin_lock(&pcwd_private.io_lock);
494 	if (pcwd_private.revision == PCWD_REVISION_A)
495 		/* Rev A cards return status information from
496 		 * the base register, which is used for the
497 		 * temperature in other cards. */
498 		control_status = inb(pcwd_private.io_addr);
499 	else {
500 		/* Rev C cards return card status in the base
501 		 * address + 1 register. And use different bits
502 		 * to indicate a card initiated reset, and an
503 		 * over-temperature condition. And the reboot
504 		 * status can be reset. */
505 		control_status = inb(pcwd_private.io_addr + 1);
506 	}
507 	spin_unlock(&pcwd_private.io_lock);
508 
509 	if (pcwd_private.revision == PCWD_REVISION_A) {
510 		if (control_status & WD_WDRST)
511 			*status |= WDIOF_CARDRESET;
512 
513 		if (control_status & WD_T110) {
514 			*status |= WDIOF_OVERHEAT;
515 			if (temp_panic) {
516 				printk(KERN_INFO PFX
517 					"Temperature overheat trip!\n");
518 				kernel_power_off();
519 			}
520 		}
521 	} else {
522 		if (control_status & WD_REVC_WTRP)
523 			*status |= WDIOF_CARDRESET;
524 
525 		if (control_status & WD_REVC_TTRP) {
526 			*status |= WDIOF_OVERHEAT;
527 			if (temp_panic) {
528 				printk(KERN_INFO PFX
529 					"Temperature overheat trip!\n");
530 				kernel_power_off();
531 			}
532 		}
533 	}
534 
535 	return 0;
536 }
537 
538 static int pcwd_clear_status(void)
539 {
540 	int control_status;
541 
542 	if (pcwd_private.revision == PCWD_REVISION_C) {
543 		spin_lock(&pcwd_private.io_lock);
544 
545 		if (debug >= VERBOSE)
546 			printk(KERN_INFO PFX
547 					"clearing watchdog trip status\n");
548 
549 		control_status = inb_p(pcwd_private.io_addr + 1);
550 
551 		if (debug >= DEBUG) {
552 			printk(KERN_DEBUG PFX "status was: 0x%02x\n",
553 				control_status);
554 			printk(KERN_DEBUG PFX "sending: 0x%02x\n",
555 				(control_status & WD_REVC_R2DS));
556 		}
557 
558 		/* clear reset status & Keep Relay 2 disable state as it is */
559 		outb_p((control_status & WD_REVC_R2DS),
560 						pcwd_private.io_addr + 1);
561 
562 		spin_unlock(&pcwd_private.io_lock);
563 	}
564 	return 0;
565 }
566 
567 static int pcwd_get_temperature(int *temperature)
568 {
569 	/* check that port 0 gives temperature info and no command results */
570 	if (pcwd_private.command_mode)
571 		return -1;
572 
573 	*temperature = 0;
574 	if (!pcwd_private.supports_temp)
575 		return -ENODEV;
576 
577 	/*
578 	 * Convert celsius to fahrenheit, since this was
579 	 * the decided 'standard' for this return value.
580 	 */
581 	spin_lock(&pcwd_private.io_lock);
582 	*temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
583 	spin_unlock(&pcwd_private.io_lock);
584 
585 	if (debug >= DEBUG) {
586 		printk(KERN_DEBUG PFX "temperature is: %d F\n",
587 			*temperature);
588 	}
589 
590 	return 0;
591 }
592 
593 /*
594  *	/dev/watchdog handling
595  */
596 
597 static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
598 {
599 	int rv;
600 	int status;
601 	int temperature;
602 	int new_heartbeat;
603 	int __user *argp = (int __user *)arg;
604 	static struct watchdog_info ident = {
605 		.options =		WDIOF_OVERHEAT |
606 					WDIOF_CARDRESET |
607 					WDIOF_KEEPALIVEPING |
608 					WDIOF_SETTIMEOUT |
609 					WDIOF_MAGICCLOSE,
610 		.firmware_version =	1,
611 		.identity =		"PCWD",
612 	};
613 
614 	switch (cmd) {
615 	case WDIOC_GETSUPPORT:
616 		if (copy_to_user(argp, &ident, sizeof(ident)))
617 			return -EFAULT;
618 		return 0;
619 
620 	case WDIOC_GETSTATUS:
621 		pcwd_get_status(&status);
622 		return put_user(status, argp);
623 
624 	case WDIOC_GETBOOTSTATUS:
625 		return put_user(pcwd_private.boot_status, argp);
626 
627 	case WDIOC_GETTEMP:
628 		if (pcwd_get_temperature(&temperature))
629 			return -EFAULT;
630 
631 		return put_user(temperature, argp);
632 
633 	case WDIOC_SETOPTIONS:
634 		if (pcwd_private.revision == PCWD_REVISION_C) {
635 			if (get_user(rv, argp))
636 				return -EFAULT;
637 
638 			if (rv & WDIOS_DISABLECARD) {
639 				status = pcwd_stop();
640 				if (status < 0)
641 					return status;
642 			}
643 			if (rv & WDIOS_ENABLECARD) {
644 				status = pcwd_start();
645 				if (status < 0)
646 					return status;
647 			}
648 			if (rv & WDIOS_TEMPPANIC)
649 				temp_panic = 1;
650 		}
651 		return -EINVAL;
652 
653 	case WDIOC_KEEPALIVE:
654 		pcwd_keepalive();
655 		return 0;
656 
657 	case WDIOC_SETTIMEOUT:
658 		if (get_user(new_heartbeat, argp))
659 			return -EFAULT;
660 
661 		if (pcwd_set_heartbeat(new_heartbeat))
662 			return -EINVAL;
663 
664 		pcwd_keepalive();
665 		/* Fall */
666 
667 	case WDIOC_GETTIMEOUT:
668 		return put_user(heartbeat, argp);
669 
670 	default:
671 		return -ENOTTY;
672 	}
673 
674 	return 0;
675 }
676 
677 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
678 			  loff_t *ppos)
679 {
680 	if (len) {
681 		if (!nowayout) {
682 			size_t i;
683 
684 			/* In case it was set long ago */
685 			expect_close = 0;
686 
687 			for (i = 0; i != len; i++) {
688 				char c;
689 
690 				if (get_user(c, buf + i))
691 					return -EFAULT;
692 				if (c == 'V')
693 					expect_close = 42;
694 			}
695 		}
696 		pcwd_keepalive();
697 	}
698 	return len;
699 }
700 
701 static int pcwd_open(struct inode *inode, struct file *file)
702 {
703 	if (test_and_set_bit(0, &open_allowed))
704 		return -EBUSY;
705 	if (nowayout)
706 		__module_get(THIS_MODULE);
707 	/* Activate */
708 	pcwd_start();
709 	pcwd_keepalive();
710 	return nonseekable_open(inode, file);
711 }
712 
713 static int pcwd_close(struct inode *inode, struct file *file)
714 {
715 	if (expect_close == 42)
716 		pcwd_stop();
717 	else {
718 		printk(KERN_CRIT PFX
719 			"Unexpected close, not stopping watchdog!\n");
720 		pcwd_keepalive();
721 	}
722 	expect_close = 0;
723 	clear_bit(0, &open_allowed);
724 	return 0;
725 }
726 
727 /*
728  *	/dev/temperature handling
729  */
730 
731 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
732 			 loff_t *ppos)
733 {
734 	int temperature;
735 
736 	if (pcwd_get_temperature(&temperature))
737 		return -EFAULT;
738 
739 	if (copy_to_user(buf, &temperature, 1))
740 		return -EFAULT;
741 
742 	return 1;
743 }
744 
745 static int pcwd_temp_open(struct inode *inode, struct file *file)
746 {
747 	if (!pcwd_private.supports_temp)
748 		return -ENODEV;
749 
750 	return nonseekable_open(inode, file);
751 }
752 
753 static int pcwd_temp_close(struct inode *inode, struct file *file)
754 {
755 	return 0;
756 }
757 
758 /*
759  *	Kernel Interfaces
760  */
761 
762 static const struct file_operations pcwd_fops = {
763 	.owner		= THIS_MODULE,
764 	.llseek		= no_llseek,
765 	.write		= pcwd_write,
766 	.unlocked_ioctl	= pcwd_ioctl,
767 	.open		= pcwd_open,
768 	.release	= pcwd_close,
769 };
770 
771 static struct miscdevice pcwd_miscdev = {
772 	.minor =	WATCHDOG_MINOR,
773 	.name =		"watchdog",
774 	.fops =		&pcwd_fops,
775 };
776 
777 static const struct file_operations pcwd_temp_fops = {
778 	.owner		= THIS_MODULE,
779 	.llseek		= no_llseek,
780 	.read		= pcwd_temp_read,
781 	.open		= pcwd_temp_open,
782 	.release	= pcwd_temp_close,
783 };
784 
785 static struct miscdevice temp_miscdev = {
786 	.minor =	TEMP_MINOR,
787 	.name =		"temperature",
788 	.fops =		&pcwd_temp_fops,
789 };
790 
791 /*
792  *	Init & exit routines
793  */
794 
795 static inline int get_revision(void)
796 {
797 	int r = PCWD_REVISION_C;
798 
799 	spin_lock(&pcwd_private.io_lock);
800 	/* REV A cards use only 2 io ports; test
801 	 * presumes a floating bus reads as 0xff. */
802 	if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
803 	    (inb(pcwd_private.io_addr + 3) == 0xFF))
804 		r = PCWD_REVISION_A;
805 	spin_unlock(&pcwd_private.io_lock);
806 
807 	return r;
808 }
809 
810 /*
811  *  The ISA cards have a heartbeat bit in one of the registers, which
812  *  register is card dependent.  The heartbeat bit is monitored, and if
813  *  found, is considered proof that a Berkshire card has been found.
814  *  The initial rate is once per second at board start up, then twice
815  *  per second for normal operation.
816  */
817 static int __devinit pcwd_isa_match(struct device *dev, unsigned int id)
818 {
819 	int base_addr = pcwd_ioports[id];
820 	int port0, last_port0;	/* Reg 0, in case it's REV A */
821 	int port1, last_port1;	/* Register 1 for REV C cards */
822 	int i;
823 	int retval;
824 
825 	if (debug >= DEBUG)
826 		printk(KERN_DEBUG PFX "pcwd_isa_match id=%d\n",
827 			id);
828 
829 	if (!request_region(base_addr, 4, "PCWD")) {
830 		printk(KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
831 		return 0;
832 	}
833 
834 	retval = 0;
835 
836 	port0 = inb_p(base_addr);	/* For REV A boards */
837 	port1 = inb_p(base_addr + 1);	/* For REV C boards */
838 	if (port0 != 0xff || port1 != 0xff) {
839 		/* Not an 'ff' from a floating bus, so must be a card! */
840 		for (i = 0; i < 4; ++i) {
841 
842 			msleep(500);
843 
844 			last_port0 = port0;
845 			last_port1 = port1;
846 
847 			port0 = inb_p(base_addr);
848 			port1 = inb_p(base_addr + 1);
849 
850 			/* Has either hearbeat bit changed?  */
851 			if ((port0 ^ last_port0) & WD_HRTBT ||
852 			    (port1 ^ last_port1) & WD_REVC_HRBT) {
853 				retval = 1;
854 				break;
855 			}
856 		}
857 	}
858 	release_region(base_addr, 4);
859 
860 	return retval;
861 }
862 
863 static int __devinit pcwd_isa_probe(struct device *dev, unsigned int id)
864 {
865 	int ret;
866 
867 	if (debug >= DEBUG)
868 		printk(KERN_DEBUG PFX "pcwd_isa_probe id=%d\n",
869 			id);
870 
871 	cards_found++;
872 	if (cards_found == 1)
873 		printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n",
874 								WD_VER);
875 
876 	if (cards_found > 1) {
877 		printk(KERN_ERR PFX "This driver only supports 1 device\n");
878 		return -ENODEV;
879 	}
880 
881 	if (pcwd_ioports[id] == 0x0000) {
882 		printk(KERN_ERR PFX "No I/O-Address for card detected\n");
883 		return -ENODEV;
884 	}
885 	pcwd_private.io_addr = pcwd_ioports[id];
886 
887 	spin_lock_init(&pcwd_private.io_lock);
888 
889 	/* Check card's revision */
890 	pcwd_private.revision = get_revision();
891 
892 	if (!request_region(pcwd_private.io_addr,
893 		(pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
894 		printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
895 			pcwd_private.io_addr);
896 		ret = -EIO;
897 		goto error_request_region;
898 	}
899 
900 	/* Initial variables */
901 	pcwd_private.supports_temp = 0;
902 	temp_panic = 0;
903 	pcwd_private.boot_status = 0x0000;
904 
905 	/* get the boot_status */
906 	pcwd_get_status(&pcwd_private.boot_status);
907 
908 	/* clear the "card caused reboot" flag */
909 	pcwd_clear_status();
910 
911 	setup_timer(&pcwd_private.timer, pcwd_timer_ping, 0);
912 
913 	/*  Disable the board  */
914 	pcwd_stop();
915 
916 	/*  Check whether or not the card supports the temperature device */
917 	pcwd_check_temperature_support();
918 
919 	/* Show info about the card itself */
920 	pcwd_show_card_info();
921 
922 	/* If heartbeat = 0 then we use the heartbeat from the dip-switches */
923 	if (heartbeat == 0)
924 		heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
925 
926 	/* Check that the heartbeat value is within it's range;
927 	   if not reset to the default */
928 	if (pcwd_set_heartbeat(heartbeat)) {
929 		pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
930 		printk(KERN_INFO PFX
931 		  "heartbeat value must be 2 <= heartbeat <= 7200, using %d\n",
932 							WATCHDOG_HEARTBEAT);
933 	}
934 
935 	if (pcwd_private.supports_temp) {
936 		ret = misc_register(&temp_miscdev);
937 		if (ret) {
938 			printk(KERN_ERR PFX
939 			    "cannot register miscdev on minor=%d (err=%d)\n",
940 							TEMP_MINOR, ret);
941 			goto error_misc_register_temp;
942 		}
943 	}
944 
945 	ret = misc_register(&pcwd_miscdev);
946 	if (ret) {
947 		printk(KERN_ERR PFX
948 			"cannot register miscdev on minor=%d (err=%d)\n",
949 					WATCHDOG_MINOR, ret);
950 		goto error_misc_register_watchdog;
951 	}
952 
953 	printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
954 		heartbeat, nowayout);
955 
956 	return 0;
957 
958 error_misc_register_watchdog:
959 	if (pcwd_private.supports_temp)
960 		misc_deregister(&temp_miscdev);
961 error_misc_register_temp:
962 	release_region(pcwd_private.io_addr,
963 			(pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
964 error_request_region:
965 	pcwd_private.io_addr = 0x0000;
966 	cards_found--;
967 	return ret;
968 }
969 
970 static int __devexit pcwd_isa_remove(struct device *dev, unsigned int id)
971 {
972 	if (debug >= DEBUG)
973 		printk(KERN_DEBUG PFX "pcwd_isa_remove id=%d\n",
974 			id);
975 
976 	if (!pcwd_private.io_addr)
977 		return 1;
978 
979 	/*  Disable the board  */
980 	if (!nowayout)
981 		pcwd_stop();
982 
983 	/* Deregister */
984 	misc_deregister(&pcwd_miscdev);
985 	if (pcwd_private.supports_temp)
986 		misc_deregister(&temp_miscdev);
987 	release_region(pcwd_private.io_addr,
988 			(pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
989 	pcwd_private.io_addr = 0x0000;
990 	cards_found--;
991 
992 	return 0;
993 }
994 
995 static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
996 {
997 	if (debug >= DEBUG)
998 		printk(KERN_DEBUG PFX "pcwd_isa_shutdown id=%d\n",
999 			id);
1000 
1001 	pcwd_stop();
1002 }
1003 
1004 static struct isa_driver pcwd_isa_driver = {
1005 	.match		= pcwd_isa_match,
1006 	.probe		= pcwd_isa_probe,
1007 	.remove		= __devexit_p(pcwd_isa_remove),
1008 	.shutdown	= pcwd_isa_shutdown,
1009 	.driver		= {
1010 		.owner	= THIS_MODULE,
1011 		.name	= WATCHDOG_NAME,
1012 	},
1013 };
1014 
1015 static int __init pcwd_init_module(void)
1016 {
1017 	return isa_register_driver(&pcwd_isa_driver, PCWD_ISA_NR_CARDS);
1018 }
1019 
1020 static void __exit pcwd_cleanup_module(void)
1021 {
1022 	isa_unregister_driver(&pcwd_isa_driver);
1023 	printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
1024 }
1025 
1026 module_init(pcwd_init_module);
1027 module_exit(pcwd_cleanup_module);
1028 
1029 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, Wim Van Sebroeck <wim@iguana.be>");
1030 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1031 MODULE_VERSION(WATCHDOG_VERSION);
1032 MODULE_LICENSE("GPL");
1033 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1034 MODULE_ALIAS_MISCDEV(TEMP_MINOR);
1035