xref: /openbmc/linux/drivers/watchdog/pcwd.c (revision 643d1f7f)
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 CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
44  *              Added timeout module option to override default
45  */
46 
47 /*
48  *	A bells and whistles driver is available from http://www.pcwd.de/
49  *	More info available at http://www.berkprod.com/ or http://www.pcwatchdog.com/
50  */
51 
52 #include <linux/module.h>	/* For module specific items */
53 #include <linux/moduleparam.h>	/* For new moduleparam's */
54 #include <linux/types.h>	/* For standard types (like size_t) */
55 #include <linux/errno.h>	/* For the -ENODEV/... values */
56 #include <linux/kernel.h>	/* For printk/panic/... */
57 #include <linux/delay.h>	/* For mdelay function */
58 #include <linux/timer.h>	/* For timer related operations */
59 #include <linux/jiffies.h>	/* For jiffies stuff */
60 #include <linux/miscdevice.h>	/* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
61 #include <linux/watchdog.h>	/* For the watchdog specific items */
62 #include <linux/reboot.h>	/* For kernel_power_off() */
63 #include <linux/init.h>		/* For __init/__exit/... */
64 #include <linux/fs.h>		/* For file operations */
65 #include <linux/isa.h>		/* For isa devices */
66 #include <linux/ioport.h>	/* For io-port access */
67 #include <linux/spinlock.h>	/* For spin_lock/spin_unlock/... */
68 
69 #include <asm/uaccess.h>	/* For copy_to_user/put_user/... */
70 #include <asm/io.h>		/* For inb/outb/... */
71 
72 /* Module and version information */
73 #define WATCHDOG_VERSION "1.20"
74 #define WATCHDOG_DATE "18 Feb 2007"
75 #define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
76 #define WATCHDOG_NAME "pcwd"
77 #define PFX WATCHDOG_NAME ": "
78 #define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION " (" WATCHDOG_DATE ")\n"
79 #define WD_VER WATCHDOG_VERSION " (" WATCHDOG_DATE ")"
80 
81 /*
82  * It should be noted that PCWD_REVISION_B was removed because A and B
83  * are essentially the same types of card, with the exception that B
84  * has temperature reporting.  Since I didn't receive a Rev.B card,
85  * the Rev.B card is not supported.  (It's a good thing too, as they
86  * are no longer in production.)
87  */
88 #define	PCWD_REVISION_A		1
89 #define	PCWD_REVISION_C		2
90 
91 /*
92  * These are the auto-probe addresses available.
93  *
94  * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
95  * Revision A has an address range of 2 addresses, while Revision C has 4.
96  */
97 #define PCWD_ISA_NR_CARDS	3
98 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
99 
100 /*
101  * These are the defines that describe the control status bits for the
102  * PCI-PC Watchdog card.
103 */
104 /* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
105 #define WD_WDRST		0x01	/* Previously reset state */
106 #define WD_T110			0x02	/* Temperature overheat sense */
107 #define WD_HRTBT		0x04	/* Heartbeat sense */
108 #define WD_RLY2			0x08	/* External relay triggered */
109 #define WD_SRLY2		0x80	/* Software external relay triggered */
110 /* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
111 #define WD_REVC_WTRP		0x01	/* Watchdog Trip status */
112 #define WD_REVC_HRBT		0x02	/* Watchdog Heartbeat */
113 #define WD_REVC_TTRP		0x04	/* Temperature Trip status */
114 #define WD_REVC_RL2A		0x08	/* Relay 2 activated by on-board processor */
115 #define WD_REVC_RL1A		0x10	/* Relay 1 active */
116 #define WD_REVC_R2DS		0x40	/* Relay 2 disable */
117 #define WD_REVC_RLY2		0x80	/* Relay 2 activated? */
118 /* Port 2 : Control Status #2 */
119 #define WD_WDIS			0x10	/* Watchdog Disabled */
120 #define WD_ENTP			0x20	/* Watchdog Enable Temperature Trip */
121 #define WD_SSEL			0x40	/* Watchdog Switch Select (1:SW1 <-> 0:SW2) */
122 #define WD_WCMD			0x80	/* Watchdog Command Mode */
123 
124 /* max. time we give an ISA watchdog card to process a command */
125 /* 500ms for each 4 bit response (according to spec.) */
126 #define ISA_COMMAND_TIMEOUT     1000
127 
128 /* Watchdog's internal commands */
129 #define CMD_ISA_IDLE			0x00
130 #define CMD_ISA_VERSION_INTEGER		0x01
131 #define CMD_ISA_VERSION_TENTH		0x02
132 #define CMD_ISA_VERSION_HUNDRETH	0x03
133 #define CMD_ISA_VERSION_MINOR		0x04
134 #define CMD_ISA_SWITCH_SETTINGS		0x05
135 #define CMD_ISA_RESET_PC		0x06
136 #define CMD_ISA_ARM_0			0x07
137 #define CMD_ISA_ARM_30			0x08
138 #define CMD_ISA_ARM_60			0x09
139 #define CMD_ISA_DELAY_TIME_2SECS	0x0A
140 #define CMD_ISA_DELAY_TIME_4SECS	0x0B
141 #define CMD_ISA_DELAY_TIME_8SECS	0x0C
142 #define CMD_ISA_RESET_RELAYS		0x0D
143 
144 /* Watchdog's Dip Switch heartbeat values */
145 static const int heartbeat_tbl [] = {
146 	20,	/* OFF-OFF-OFF	= 20 Sec  */
147 	40,	/* OFF-OFF-ON	= 40 Sec  */
148 	60,	/* OFF-ON-OFF	=  1 Min  */
149 	300,	/* OFF-ON-ON	=  5 Min  */
150 	600,	/* ON-OFF-OFF	= 10 Min  */
151 	1800,	/* ON-OFF-ON	= 30 Min  */
152 	3600,	/* ON-ON-OFF	=  1 Hour */
153 	7200,	/* ON-ON-ON	=  2 hour */
154 };
155 
156 /*
157  * We are using an kernel timer to do the pinging of the watchdog
158  * every ~500ms. We try to set the internal heartbeat of the
159  * watchdog to 2 ms.
160  */
161 
162 #define WDT_INTERVAL (HZ/2+1)
163 
164 /* We can only use 1 card due to the /dev/watchdog restriction */
165 static int cards_found;
166 
167 /* internal variables */
168 static atomic_t open_allowed = ATOMIC_INIT(1);
169 static char expect_close;
170 static int temp_panic;
171 static struct {				/* this is private data for each ISA-PC watchdog card */
172 	char fw_ver_str[6];		/* The cards firmware version */
173 	int revision;			/* The card's revision */
174 	int supports_temp;		/* Wether or not the card has a temperature device */
175 	int command_mode;		/* Wether or not the card is in command mode */
176 	int boot_status;		/* The card's boot status */
177 	int io_addr;			/* The cards I/O address */
178 	spinlock_t io_lock;		/* the lock for io operations */
179 	struct timer_list timer;	/* The timer that pings the watchdog */
180 	unsigned long next_heartbeat;	/* the next_heartbeat for the timer */
181 } pcwd_private;
182 
183 /* module parameters */
184 #define QUIET	0	/* Default */
185 #define VERBOSE	1	/* Verbose */
186 #define DEBUG	2	/* print fancy stuff too */
187 static int debug = QUIET;
188 module_param(debug, int, 0);
189 MODULE_PARM_DESC(debug, "Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
190 
191 #define WATCHDOG_HEARTBEAT 0		/* default heartbeat = delay-time from dip-switches */
192 static int heartbeat = WATCHDOG_HEARTBEAT;
193 module_param(heartbeat, int, 0);
194 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<=heartbeat<=7200 or 0=delay-time from dip-switches, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
195 
196 static int nowayout = WATCHDOG_NOWAYOUT;
197 module_param(nowayout, int, 0);
198 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
199 
200 /*
201  *	Internal functions
202  */
203 
204 static int send_isa_command(int cmd)
205 {
206 	int i;
207 	int control_status;
208 	int port0, last_port0;	/* Double read for stabilising */
209 
210 	if (debug >= DEBUG)
211 		printk(KERN_DEBUG PFX "sending following data cmd=0x%02x\n",
212 			cmd);
213 
214 	/* The WCMD bit must be 1 and the command is only 4 bits in size */
215 	control_status = (cmd & 0x0F) | WD_WCMD;
216 	outb_p(control_status, pcwd_private.io_addr + 2);
217 	udelay(ISA_COMMAND_TIMEOUT);
218 
219 	port0 = inb_p(pcwd_private.io_addr);
220 	for (i = 0; i < 25; ++i) {
221 		last_port0 = port0;
222 		port0 = inb_p(pcwd_private.io_addr);
223 
224 		if (port0 == last_port0)
225 			break;	/* Data is stable */
226 
227 		udelay (250);
228 	}
229 
230 	if (debug >= DEBUG)
231 		printk(KERN_DEBUG PFX "received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
232 			cmd, port0, last_port0);
233 
234 	return port0;
235 }
236 
237 static int set_command_mode(void)
238 {
239 	int i, found=0, count=0;
240 
241 	/* Set the card into command mode */
242 	spin_lock(&pcwd_private.io_lock);
243 	while ((!found) && (count < 3)) {
244 		i = send_isa_command(CMD_ISA_IDLE);
245 
246 		if (i == 0x00)
247 			found = 1;
248 		else if (i == 0xF3) {
249 			/* Card does not like what we've done to it */
250 			outb_p(0x00, pcwd_private.io_addr + 2);
251 			udelay(1200);	/* Spec says wait 1ms */
252 			outb_p(0x00, pcwd_private.io_addr + 2);
253 			udelay(ISA_COMMAND_TIMEOUT);
254 		}
255 		count++;
256 	}
257 	spin_unlock(&pcwd_private.io_lock);
258 	pcwd_private.command_mode = found;
259 
260 	if (debug >= DEBUG)
261 		printk(KERN_DEBUG PFX "command_mode=%d\n",
262 				pcwd_private.command_mode);
263 
264 	return(found);
265 }
266 
267 static void unset_command_mode(void)
268 {
269 	/* Set the card into normal mode */
270 	spin_lock(&pcwd_private.io_lock);
271 	outb_p(0x00, pcwd_private.io_addr + 2);
272 	udelay(ISA_COMMAND_TIMEOUT);
273 	spin_unlock(&pcwd_private.io_lock);
274 
275 	pcwd_private.command_mode = 0;
276 
277 	if (debug >= DEBUG)
278 		printk(KERN_DEBUG PFX "command_mode=%d\n",
279 				pcwd_private.command_mode);
280 }
281 
282 static inline void pcwd_check_temperature_support(void)
283 {
284 	if (inb(pcwd_private.io_addr) != 0xF0)
285 		pcwd_private.supports_temp = 1;
286 }
287 
288 static inline void pcwd_get_firmware(void)
289 {
290 	int one, ten, hund, minor;
291 
292 	strcpy(pcwd_private.fw_ver_str, "ERROR");
293 
294 	if (set_command_mode()) {
295 		one = send_isa_command(CMD_ISA_VERSION_INTEGER);
296 		ten = send_isa_command(CMD_ISA_VERSION_TENTH);
297 		hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
298 		minor = send_isa_command(CMD_ISA_VERSION_MINOR);
299 		sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c", one, ten, hund, minor);
300 	}
301 	unset_command_mode();
302 
303 	return;
304 }
305 
306 static inline int pcwd_get_option_switches(void)
307 {
308 	int option_switches=0;
309 
310 	if (set_command_mode()) {
311 		/* Get switch settings */
312 		option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
313 	}
314 
315 	unset_command_mode();
316 	return(option_switches);
317 }
318 
319 static void pcwd_show_card_info(void)
320 {
321 	int option_switches;
322 
323 	/* Get some extra info from the hardware (in command/debug/diag mode) */
324 	if (pcwd_private.revision == PCWD_REVISION_A)
325 		printk(KERN_INFO PFX "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n", pcwd_private.io_addr);
326 	else if (pcwd_private.revision == PCWD_REVISION_C) {
327 		pcwd_get_firmware();
328 		printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
329 			pcwd_private.io_addr, pcwd_private.fw_ver_str);
330 		option_switches = pcwd_get_option_switches();
331 		printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
332 			option_switches,
333 			((option_switches & 0x10) ? "ON" : "OFF"),
334 			((option_switches & 0x08) ? "ON" : "OFF"));
335 
336 		/* Reprogram internal heartbeat to 2 seconds */
337 		if (set_command_mode()) {
338 			send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
339 			unset_command_mode();
340 		}
341 	}
342 
343 	if (pcwd_private.supports_temp)
344 		printk(KERN_INFO PFX "Temperature Option Detected\n");
345 
346 	if (pcwd_private.boot_status & WDIOF_CARDRESET)
347 		printk(KERN_INFO PFX "Previous reboot was caused by the card\n");
348 
349 	if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
350 		printk(KERN_EMERG PFX "Card senses a CPU Overheat. Panicking!\n");
351 		printk(KERN_EMERG PFX "CPU Overheat\n");
352 	}
353 
354 	if (pcwd_private.boot_status == 0)
355 		printk(KERN_INFO PFX "No previous trip detected - Cold boot or reset\n");
356 }
357 
358 static void pcwd_timer_ping(unsigned long data)
359 {
360 	int wdrst_stat;
361 
362 	/* If we got a heartbeat pulse within the WDT_INTERVAL
363 	 * we agree to ping the WDT */
364 	if(time_before(jiffies, pcwd_private.next_heartbeat)) {
365 		/* Ping the watchdog */
366 		spin_lock(&pcwd_private.io_lock);
367 		if (pcwd_private.revision == PCWD_REVISION_A) {
368 			/*  Rev A cards are reset by setting the WD_WDRST bit in register 1 */
369 			wdrst_stat = inb_p(pcwd_private.io_addr);
370 			wdrst_stat &= 0x0F;
371 			wdrst_stat |= WD_WDRST;
372 
373 			outb_p(wdrst_stat, pcwd_private.io_addr + 1);
374 		} else {
375 			/* Re-trigger watchdog by writing to port 0 */
376 			outb_p(0x00, pcwd_private.io_addr);
377 		}
378 
379 		/* Re-set the timer interval */
380 		mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
381 
382 		spin_unlock(&pcwd_private.io_lock);
383 	} else {
384 		printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
385 	}
386 }
387 
388 static int pcwd_start(void)
389 {
390 	int stat_reg;
391 
392 	pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
393 
394 	/* Start the timer */
395 	mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
396 
397 	/* Enable the port */
398 	if (pcwd_private.revision == PCWD_REVISION_C) {
399 		spin_lock(&pcwd_private.io_lock);
400 		outb_p(0x00, pcwd_private.io_addr + 3);
401 		udelay(ISA_COMMAND_TIMEOUT);
402 		stat_reg = inb_p(pcwd_private.io_addr + 2);
403 		spin_unlock(&pcwd_private.io_lock);
404 		if (stat_reg & WD_WDIS) {
405 			printk(KERN_INFO PFX "Could not start watchdog\n");
406 			return -EIO;
407 		}
408 	}
409 
410 	if (debug >= VERBOSE)
411 		printk(KERN_DEBUG PFX "Watchdog started\n");
412 
413 	return 0;
414 }
415 
416 static int pcwd_stop(void)
417 {
418 	int stat_reg;
419 
420 	/* Stop the timer */
421 	del_timer(&pcwd_private.timer);
422 
423 	/*  Disable the board  */
424 	if (pcwd_private.revision == PCWD_REVISION_C) {
425 		spin_lock(&pcwd_private.io_lock);
426 		outb_p(0xA5, pcwd_private.io_addr + 3);
427 		udelay(ISA_COMMAND_TIMEOUT);
428 		outb_p(0xA5, pcwd_private.io_addr + 3);
429 		udelay(ISA_COMMAND_TIMEOUT);
430 		stat_reg = inb_p(pcwd_private.io_addr + 2);
431 		spin_unlock(&pcwd_private.io_lock);
432 		if ((stat_reg & WD_WDIS) == 0) {
433 			printk(KERN_INFO PFX "Could not stop watchdog\n");
434 			return -EIO;
435 		}
436 	}
437 
438 	if (debug >= VERBOSE)
439 		printk(KERN_DEBUG PFX "Watchdog stopped\n");
440 
441 	return 0;
442 }
443 
444 static int pcwd_keepalive(void)
445 {
446 	/* user land ping */
447 	pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
448 
449 	if (debug >= DEBUG)
450 		printk(KERN_DEBUG PFX "Watchdog keepalive signal send\n");
451 
452 	return 0;
453 }
454 
455 static int pcwd_set_heartbeat(int t)
456 {
457 	if ((t < 2) || (t > 7200)) /* arbitrary upper limit */
458 		return -EINVAL;
459 
460 	heartbeat = t;
461 
462 	if (debug >= VERBOSE)
463 		printk(KERN_DEBUG PFX "New heartbeat: %d\n",
464 		       heartbeat);
465 
466 	return 0;
467 }
468 
469 static int pcwd_get_status(int *status)
470 {
471 	int control_status;
472 
473 	*status=0;
474 	spin_lock(&pcwd_private.io_lock);
475 	if (pcwd_private.revision == PCWD_REVISION_A)
476 		/* Rev A cards return status information from
477 		 * the base register, which is used for the
478 		 * temperature in other cards. */
479 		control_status = inb(pcwd_private.io_addr);
480 	else {
481 		/* Rev C cards return card status in the base
482 		 * address + 1 register. And use different bits
483 		 * to indicate a card initiated reset, and an
484 		 * over-temperature condition. And the reboot
485 		 * status can be reset. */
486 		control_status = inb(pcwd_private.io_addr + 1);
487 	}
488 	spin_unlock(&pcwd_private.io_lock);
489 
490 	if (pcwd_private.revision == PCWD_REVISION_A) {
491 		if (control_status & WD_WDRST)
492 			*status |= WDIOF_CARDRESET;
493 
494 		if (control_status & WD_T110) {
495 			*status |= WDIOF_OVERHEAT;
496 			if (temp_panic) {
497 				printk(KERN_INFO PFX "Temperature overheat trip!\n");
498 				kernel_power_off();
499 				/* or should we just do a: panic(PFX "Temperature overheat trip!\n"); */
500 			}
501 		}
502 	} else {
503 		if (control_status & WD_REVC_WTRP)
504 			*status |= WDIOF_CARDRESET;
505 
506 		if (control_status & WD_REVC_TTRP) {
507 			*status |= WDIOF_OVERHEAT;
508 			if (temp_panic) {
509 				printk(KERN_INFO PFX "Temperature overheat trip!\n");
510 				kernel_power_off();
511 				/* or should we just do a: panic(PFX "Temperature overheat trip!\n"); */
512 			}
513 		}
514 	}
515 
516 	return 0;
517 }
518 
519 static int pcwd_clear_status(void)
520 {
521 	int control_status;
522 
523 	if (pcwd_private.revision == PCWD_REVISION_C) {
524 		spin_lock(&pcwd_private.io_lock);
525 
526 		if (debug >= VERBOSE)
527 			printk(KERN_INFO PFX "clearing watchdog trip status\n");
528 
529 		control_status = inb_p(pcwd_private.io_addr + 1);
530 
531 		if (debug >= DEBUG) {
532 			printk(KERN_DEBUG PFX "status was: 0x%02x\n", control_status);
533 			printk(KERN_DEBUG PFX "sending: 0x%02x\n",
534 				(control_status & WD_REVC_R2DS));
535 		}
536 
537 		/* clear reset status & Keep Relay 2 disable state as it is */
538 		outb_p((control_status & WD_REVC_R2DS), pcwd_private.io_addr + 1);
539 
540 		spin_unlock(&pcwd_private.io_lock);
541 	}
542 	return 0;
543 }
544 
545 static int pcwd_get_temperature(int *temperature)
546 {
547 	/* check that port 0 gives temperature info and no command results */
548 	if (pcwd_private.command_mode)
549 		return -1;
550 
551 	*temperature = 0;
552 	if (!pcwd_private.supports_temp)
553 		return -ENODEV;
554 
555 	/*
556 	 * Convert celsius to fahrenheit, since this was
557 	 * the decided 'standard' for this return value.
558 	 */
559 	spin_lock(&pcwd_private.io_lock);
560 	*temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
561 	spin_unlock(&pcwd_private.io_lock);
562 
563 	if (debug >= DEBUG) {
564 		printk(KERN_DEBUG PFX "temperature is: %d F\n",
565 			*temperature);
566 	}
567 
568 	return 0;
569 }
570 
571 /*
572  *	/dev/watchdog handling
573  */
574 
575 static int pcwd_ioctl(struct inode *inode, struct file *file,
576 		      unsigned int cmd, unsigned long arg)
577 {
578 	int rv;
579 	int status;
580 	int temperature;
581 	int new_heartbeat;
582 	int __user *argp = (int __user *)arg;
583 	static struct watchdog_info ident = {
584 		.options =		WDIOF_OVERHEAT |
585 					WDIOF_CARDRESET |
586 					WDIOF_KEEPALIVEPING |
587 					WDIOF_SETTIMEOUT |
588 					WDIOF_MAGICCLOSE,
589 		.firmware_version =	1,
590 		.identity =		"PCWD",
591 	};
592 
593 	switch(cmd) {
594 	default:
595 		return -ENOTTY;
596 
597 	case WDIOC_GETSUPPORT:
598 		if(copy_to_user(argp, &ident, sizeof(ident)))
599 			return -EFAULT;
600 		return 0;
601 
602 	case WDIOC_GETSTATUS:
603 		pcwd_get_status(&status);
604 		return put_user(status, argp);
605 
606 	case WDIOC_GETBOOTSTATUS:
607 		return put_user(pcwd_private.boot_status, argp);
608 
609 	case WDIOC_GETTEMP:
610 		if (pcwd_get_temperature(&temperature))
611 			return -EFAULT;
612 
613 		return put_user(temperature, argp);
614 
615 	case WDIOC_SETOPTIONS:
616 		if (pcwd_private.revision == PCWD_REVISION_C)
617 		{
618 			if(copy_from_user(&rv, argp, sizeof(int)))
619 				return -EFAULT;
620 
621 			if (rv & WDIOS_DISABLECARD)
622 			{
623 				return pcwd_stop();
624 			}
625 
626 			if (rv & WDIOS_ENABLECARD)
627 			{
628 				return pcwd_start();
629 			}
630 
631 			if (rv & WDIOS_TEMPPANIC)
632 			{
633 				temp_panic = 1;
634 			}
635 		}
636 		return -EINVAL;
637 
638 	case WDIOC_KEEPALIVE:
639 		pcwd_keepalive();
640 		return 0;
641 
642 	case WDIOC_SETTIMEOUT:
643 		if (get_user(new_heartbeat, argp))
644 			return -EFAULT;
645 
646 		if (pcwd_set_heartbeat(new_heartbeat))
647 			return -EINVAL;
648 
649 		pcwd_keepalive();
650 		/* Fall */
651 
652 	case WDIOC_GETTIMEOUT:
653 		return put_user(heartbeat, argp);
654 	}
655 
656 	return 0;
657 }
658 
659 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
660 			  loff_t *ppos)
661 {
662 	if (len) {
663 		if (!nowayout) {
664 			size_t i;
665 
666 			/* In case it was set long ago */
667 			expect_close = 0;
668 
669 			for (i = 0; i != len; i++) {
670 				char c;
671 
672 				if (get_user(c, buf + i))
673 					return -EFAULT;
674 				if (c == 'V')
675 					expect_close = 42;
676 			}
677 		}
678 		pcwd_keepalive();
679 	}
680 	return len;
681 }
682 
683 static int pcwd_open(struct inode *inode, struct file *file)
684 {
685 	if (!atomic_dec_and_test(&open_allowed) ) {
686 		if (debug >= VERBOSE)
687 			printk(KERN_ERR PFX "Attempt to open already opened device.\n");
688 		atomic_inc( &open_allowed );
689 		return -EBUSY;
690 	}
691 
692 	if (nowayout)
693 		__module_get(THIS_MODULE);
694 
695 	/* Activate */
696 	pcwd_start();
697 	pcwd_keepalive();
698 	return nonseekable_open(inode, file);
699 }
700 
701 static int pcwd_close(struct inode *inode, struct file *file)
702 {
703 	if (expect_close == 42) {
704 		pcwd_stop();
705 	} else {
706 		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
707 		pcwd_keepalive();
708 	}
709 	expect_close = 0;
710 	atomic_inc( &open_allowed );
711 	return 0;
712 }
713 
714 /*
715  *	/dev/temperature handling
716  */
717 
718 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
719 			 loff_t *ppos)
720 {
721 	int temperature;
722 
723 	if (pcwd_get_temperature(&temperature))
724 		return -EFAULT;
725 
726 	if (copy_to_user(buf, &temperature, 1))
727 		return -EFAULT;
728 
729 	return 1;
730 }
731 
732 static int pcwd_temp_open(struct inode *inode, struct file *file)
733 {
734 	if (!pcwd_private.supports_temp)
735 		return -ENODEV;
736 
737 	return nonseekable_open(inode, file);
738 }
739 
740 static int pcwd_temp_close(struct inode *inode, struct file *file)
741 {
742 	return 0;
743 }
744 
745 /*
746  *	Kernel Interfaces
747  */
748 
749 static const struct file_operations pcwd_fops = {
750 	.owner		= THIS_MODULE,
751 	.llseek		= no_llseek,
752 	.write		= pcwd_write,
753 	.ioctl		= pcwd_ioctl,
754 	.open		= pcwd_open,
755 	.release	= pcwd_close,
756 };
757 
758 static struct miscdevice pcwd_miscdev = {
759 	.minor =	WATCHDOG_MINOR,
760 	.name =		"watchdog",
761 	.fops =		&pcwd_fops,
762 };
763 
764 static const struct file_operations pcwd_temp_fops = {
765 	.owner		= THIS_MODULE,
766 	.llseek		= no_llseek,
767 	.read		= pcwd_temp_read,
768 	.open		= pcwd_temp_open,
769 	.release	= pcwd_temp_close,
770 };
771 
772 static struct miscdevice temp_miscdev = {
773 	.minor =	TEMP_MINOR,
774 	.name =		"temperature",
775 	.fops =		&pcwd_temp_fops,
776 };
777 
778 /*
779  *	Init & exit routines
780  */
781 
782 static inline int get_revision(void)
783 {
784 	int r = PCWD_REVISION_C;
785 
786 	spin_lock(&pcwd_private.io_lock);
787 	/* REV A cards use only 2 io ports; test
788 	 * presumes a floating bus reads as 0xff. */
789 	if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
790 	    (inb(pcwd_private.io_addr + 3) == 0xFF))
791 		r=PCWD_REVISION_A;
792 	spin_unlock(&pcwd_private.io_lock);
793 
794 	return r;
795 }
796 
797 /*
798  *  The ISA cards have a heartbeat bit in one of the registers, which
799  *  register is card dependent.  The heartbeat bit is monitored, and if
800  *  found, is considered proof that a Berkshire card has been found.
801  *  The initial rate is once per second at board start up, then twice
802  *  per second for normal operation.
803  */
804 static int __devinit pcwd_isa_match(struct device *dev, unsigned int id)
805 {
806 	int base_addr=pcwd_ioports[id];
807 	int port0, last_port0;	/* Reg 0, in case it's REV A */
808 	int port1, last_port1;	/* Register 1 for REV C cards */
809 	int i;
810 	int retval;
811 
812 	if (debug >= DEBUG)
813 		printk(KERN_DEBUG PFX "pcwd_isa_match id=%d\n",
814 			id);
815 
816 	if (!request_region (base_addr, 4, "PCWD")) {
817 		printk(KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
818 		return 0;
819 	}
820 
821 	retval = 0;
822 
823 	port0 = inb_p(base_addr);	/* For REV A boards */
824 	port1 = inb_p(base_addr + 1);	/* For REV C boards */
825 	if (port0 != 0xff || port1 != 0xff) {
826 		/* Not an 'ff' from a floating bus, so must be a card! */
827 		for (i = 0; i < 4; ++i) {
828 
829 			msleep(500);
830 
831 			last_port0 = port0;
832 			last_port1 = port1;
833 
834 			port0 = inb_p(base_addr);
835 			port1 = inb_p(base_addr + 1);
836 
837 			/* Has either hearbeat bit changed?  */
838 			if ((port0 ^ last_port0) & WD_HRTBT ||
839 			    (port1 ^ last_port1) & WD_REVC_HRBT) {
840 				retval = 1;
841 				break;
842 			}
843 		}
844 	}
845 	release_region (base_addr, 4);
846 
847 	return retval;
848 }
849 
850 static int __devinit pcwd_isa_probe(struct device *dev, unsigned int id)
851 {
852 	int ret;
853 
854 	if (debug >= DEBUG)
855 		printk(KERN_DEBUG PFX "pcwd_isa_probe id=%d\n",
856 			id);
857 
858 	cards_found++;
859 	if (cards_found == 1)
860 		printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n", WD_VER);
861 
862 	if (cards_found > 1) {
863 		printk(KERN_ERR PFX "This driver only supports 1 device\n");
864 		return -ENODEV;
865 	}
866 
867 	if (pcwd_ioports[id] == 0x0000) {
868 		printk(KERN_ERR PFX "No I/O-Address for card detected\n");
869 		return -ENODEV;
870 	}
871 	pcwd_private.io_addr = pcwd_ioports[id];
872 
873 	spin_lock_init(&pcwd_private.io_lock);
874 
875 	/* Check card's revision */
876 	pcwd_private.revision = get_revision();
877 
878 	if (!request_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
879 		printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
880 			pcwd_private.io_addr);
881 		ret=-EIO;
882 		goto error_request_region;
883 	}
884 
885 	/* Initial variables */
886 	pcwd_private.supports_temp = 0;
887 	temp_panic = 0;
888 	pcwd_private.boot_status = 0x0000;
889 
890 	/* get the boot_status */
891 	pcwd_get_status(&pcwd_private.boot_status);
892 
893 	/* clear the "card caused reboot" flag */
894 	pcwd_clear_status();
895 
896 	setup_timer(&pcwd_private.timer, pcwd_timer_ping, 0);
897 
898 	/*  Disable the board  */
899 	pcwd_stop();
900 
901 	/*  Check whether or not the card supports the temperature device */
902 	pcwd_check_temperature_support();
903 
904 	/* Show info about the card itself */
905 	pcwd_show_card_info();
906 
907 	/* If heartbeat = 0 then we use the heartbeat from the dip-switches */
908 	if (heartbeat == 0)
909 		heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
910 
911 	/* Check that the heartbeat value is within it's range ; if not reset to the default */
912 	if (pcwd_set_heartbeat(heartbeat)) {
913 		pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
914 		printk(KERN_INFO PFX "heartbeat value must be 2<=heartbeat<=7200, using %d\n",
915 			WATCHDOG_HEARTBEAT);
916 	}
917 
918 	if (pcwd_private.supports_temp) {
919 		ret = misc_register(&temp_miscdev);
920 		if (ret) {
921 			printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
922 				TEMP_MINOR, ret);
923 			goto error_misc_register_temp;
924 		}
925 	}
926 
927 	ret = misc_register(&pcwd_miscdev);
928 	if (ret) {
929 		printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
930 			WATCHDOG_MINOR, ret);
931 		goto error_misc_register_watchdog;
932 	}
933 
934 	printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
935 		heartbeat, nowayout);
936 
937 	return 0;
938 
939 error_misc_register_watchdog:
940 	if (pcwd_private.supports_temp)
941 		misc_deregister(&temp_miscdev);
942 error_misc_register_temp:
943 	release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
944 error_request_region:
945 	pcwd_private.io_addr = 0x0000;
946 	cards_found--;
947 	return ret;
948 }
949 
950 static int __devexit pcwd_isa_remove(struct device *dev, unsigned int id)
951 {
952 	if (debug >= DEBUG)
953 		printk(KERN_DEBUG PFX "pcwd_isa_remove id=%d\n",
954 			id);
955 
956 	if (!pcwd_private.io_addr)
957 		return 1;
958 
959 	/*  Disable the board  */
960 	if (!nowayout)
961 		pcwd_stop();
962 
963 	/* Deregister */
964 	misc_deregister(&pcwd_miscdev);
965 	if (pcwd_private.supports_temp)
966 		misc_deregister(&temp_miscdev);
967 	release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
968 	pcwd_private.io_addr = 0x0000;
969 	cards_found--;
970 
971 	return 0;
972 }
973 
974 static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
975 {
976 	if (debug >= DEBUG)
977 		printk(KERN_DEBUG PFX "pcwd_isa_shutdown id=%d\n",
978 			id);
979 
980 	pcwd_stop();
981 }
982 
983 static struct isa_driver pcwd_isa_driver = {
984 	.match		= pcwd_isa_match,
985 	.probe		= pcwd_isa_probe,
986 	.remove		= __devexit_p(pcwd_isa_remove),
987 	.shutdown	= pcwd_isa_shutdown,
988 	.driver		= {
989 		.owner	= THIS_MODULE,
990 		.name	= WATCHDOG_NAME,
991 	},
992 };
993 
994 static int __init pcwd_init_module(void)
995 {
996 	return isa_register_driver(&pcwd_isa_driver, PCWD_ISA_NR_CARDS);
997 }
998 
999 static void __exit pcwd_cleanup_module(void)
1000 {
1001 	isa_unregister_driver(&pcwd_isa_driver);
1002 	printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
1003 }
1004 
1005 module_init(pcwd_init_module);
1006 module_exit(pcwd_cleanup_module);
1007 
1008 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, Wim Van Sebroeck <wim@iguana.be>");
1009 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1010 MODULE_VERSION(WATCHDOG_VERSION);
1011 MODULE_LICENSE("GPL");
1012 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1013 MODULE_ALIAS_MISCDEV(TEMP_MINOR);
1014