Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6.git] / drivers / watchdog / pcwd.c
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 "\n"
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
115                                                         on-board processor */
116 #define WD_REVC_RL1A            0x10    /* Relay 1 active */
117 #define WD_REVC_R2DS            0x40    /* Relay 2 disable */
118 #define WD_REVC_RLY2            0x80    /* Relay 2 activated? */
119 /* Port 2 : Control Status #2 */
120 #define WD_WDIS                 0x10    /* Watchdog Disabled */
121 #define WD_ENTP                 0x20    /* Watchdog Enable Temperature Trip */
122 #define WD_SSEL                 0x40    /* Watchdog Switch Select
123                                                         (1:SW1 <-> 0:SW2) */
124 #define WD_WCMD                 0x80    /* Watchdog Command Mode */
125
126 /* max. time we give an ISA watchdog card to process a command */
127 /* 500ms for each 4 bit response (according to spec.) */
128 #define ISA_COMMAND_TIMEOUT     1000
129
130 /* Watchdog's internal commands */
131 #define CMD_ISA_IDLE                    0x00
132 #define CMD_ISA_VERSION_INTEGER         0x01
133 #define CMD_ISA_VERSION_TENTH           0x02
134 #define CMD_ISA_VERSION_HUNDRETH        0x03
135 #define CMD_ISA_VERSION_MINOR           0x04
136 #define CMD_ISA_SWITCH_SETTINGS         0x05
137 #define CMD_ISA_RESET_PC                0x06
138 #define CMD_ISA_ARM_0                   0x07
139 #define CMD_ISA_ARM_30                  0x08
140 #define CMD_ISA_ARM_60                  0x09
141 #define CMD_ISA_DELAY_TIME_2SECS        0x0A
142 #define CMD_ISA_DELAY_TIME_4SECS        0x0B
143 #define CMD_ISA_DELAY_TIME_8SECS        0x0C
144 #define CMD_ISA_RESET_RELAYS            0x0D
145
146 /* Watchdog's Dip Switch heartbeat values */
147 static const int heartbeat_tbl[] = {
148         20,     /* OFF-OFF-OFF  = 20 Sec  */
149         40,     /* OFF-OFF-ON   = 40 Sec  */
150         60,     /* OFF-ON-OFF   =  1 Min  */
151         300,    /* OFF-ON-ON    =  5 Min  */
152         600,    /* ON-OFF-OFF   = 10 Min  */
153         1800,   /* ON-OFF-ON    = 30 Min  */
154         3600,   /* ON-ON-OFF    =  1 Hour */
155         7200,   /* ON-ON-ON     =  2 hour */
156 };
157
158 /*
159  * We are using an kernel timer to do the pinging of the watchdog
160  * every ~500ms. We try to set the internal heartbeat of the
161  * watchdog to 2 ms.
162  */
163
164 #define WDT_INTERVAL (HZ/2+1)
165
166 /* We can only use 1 card due to the /dev/watchdog restriction */
167 static int cards_found;
168
169 /* internal variables */
170 static unsigned long open_allowed;
171 static char expect_close;
172 static int temp_panic;
173
174 /* this is private data for each ISA-PC watchdog card */
175 static struct {
176         char fw_ver_str[6];             /* The cards firmware version */
177         int revision;                   /* The card's revision */
178         int supports_temp;              /* Whether or not the card has
179                                                 a temperature device */
180         int command_mode;               /* Whether or not the card is in
181                                                 command mode */
182         int boot_status;                /* The card's boot status */
183         int io_addr;                    /* The cards I/O address */
184         spinlock_t io_lock;             /* the lock for io operations */
185         struct timer_list timer;        /* The timer that pings the watchdog */
186         unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
187 } pcwd_private;
188
189 /* module parameters */
190 #define QUIET   0       /* Default */
191 #define VERBOSE 1       /* Verbose */
192 #define DEBUG   2       /* print fancy stuff too */
193 static int debug = QUIET;
194 module_param(debug, int, 0);
195 MODULE_PARM_DESC(debug,
196                 "Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
197
198 /* default heartbeat = delay-time from dip-switches */
199 #define WATCHDOG_HEARTBEAT 0
200 static int heartbeat = WATCHDOG_HEARTBEAT;
201 module_param(heartbeat, int, 0);
202 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
203         "(2 <= heartbeat <= 7200 or 0=delay-time from dip-switches, default="
204                                 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
205
206 static int nowayout = WATCHDOG_NOWAYOUT;
207 module_param(nowayout, int, 0);
208 MODULE_PARM_DESC(nowayout,
209                 "Watchdog cannot be stopped once started (default="
210                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
211
212 /*
213  *      Internal functions
214  */
215
216 static int send_isa_command(int cmd)
217 {
218         int i;
219         int control_status;
220         int port0, last_port0;  /* Double read for stabilising */
221
222         if (debug >= DEBUG)
223                 printk(KERN_DEBUG PFX "sending following data cmd=0x%02x\n",
224                         cmd);
225
226         /* The WCMD bit must be 1 and the command is only 4 bits in size */
227         control_status = (cmd & 0x0F) | WD_WCMD;
228         outb_p(control_status, pcwd_private.io_addr + 2);
229         udelay(ISA_COMMAND_TIMEOUT);
230
231         port0 = inb_p(pcwd_private.io_addr);
232         for (i = 0; i < 25; ++i) {
233                 last_port0 = port0;
234                 port0 = inb_p(pcwd_private.io_addr);
235
236                 if (port0 == last_port0)
237                         break;  /* Data is stable */
238
239                 udelay(250);
240         }
241
242         if (debug >= DEBUG)
243                 printk(KERN_DEBUG PFX "received following data for "
244                         "cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
245                         cmd, port0, last_port0);
246
247         return port0;
248 }
249
250 static int set_command_mode(void)
251 {
252         int i, found = 0, count = 0;
253
254         /* Set the card into command mode */
255         spin_lock(&pcwd_private.io_lock);
256         while ((!found) && (count < 3)) {
257                 i = send_isa_command(CMD_ISA_IDLE);
258
259                 if (i == 0x00)
260                         found = 1;
261                 else if (i == 0xF3) {
262                         /* Card does not like what we've done to it */
263                         outb_p(0x00, pcwd_private.io_addr + 2);
264                         udelay(1200);   /* Spec says wait 1ms */
265                         outb_p(0x00, pcwd_private.io_addr + 2);
266                         udelay(ISA_COMMAND_TIMEOUT);
267                 }
268                 count++;
269         }
270         spin_unlock(&pcwd_private.io_lock);
271         pcwd_private.command_mode = found;
272
273         if (debug >= DEBUG)
274                 printk(KERN_DEBUG PFX "command_mode=%d\n",
275                                 pcwd_private.command_mode);
276
277         return found;
278 }
279
280 static void unset_command_mode(void)
281 {
282         /* Set the card into normal mode */
283         spin_lock(&pcwd_private.io_lock);
284         outb_p(0x00, pcwd_private.io_addr + 2);
285         udelay(ISA_COMMAND_TIMEOUT);
286         spin_unlock(&pcwd_private.io_lock);
287
288         pcwd_private.command_mode = 0;
289
290         if (debug >= DEBUG)
291                 printk(KERN_DEBUG PFX "command_mode=%d\n",
292                                 pcwd_private.command_mode);
293 }
294
295 static inline void pcwd_check_temperature_support(void)
296 {
297         if (inb(pcwd_private.io_addr) != 0xF0)
298                 pcwd_private.supports_temp = 1;
299 }
300
301 static inline void pcwd_get_firmware(void)
302 {
303         int one, ten, hund, minor;
304
305         strcpy(pcwd_private.fw_ver_str, "ERROR");
306
307         if (set_command_mode()) {
308                 one = send_isa_command(CMD_ISA_VERSION_INTEGER);
309                 ten = send_isa_command(CMD_ISA_VERSION_TENTH);
310                 hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
311                 minor = send_isa_command(CMD_ISA_VERSION_MINOR);
312                 sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c",
313                                         one, ten, hund, minor);
314         }
315         unset_command_mode();
316
317         return;
318 }
319
320 static inline int pcwd_get_option_switches(void)
321 {
322         int option_switches = 0;
323
324         if (set_command_mode()) {
325                 /* Get switch settings */
326                 option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
327         }
328
329         unset_command_mode();
330         return option_switches;
331 }
332
333 static void pcwd_show_card_info(void)
334 {
335         int option_switches;
336
337         /* Get some extra info from the hardware (in command/debug/diag mode) */
338         if (pcwd_private.revision == PCWD_REVISION_A)
339                 printk(KERN_INFO PFX
340                         "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n",
341                                                         pcwd_private.io_addr);
342         else if (pcwd_private.revision == PCWD_REVISION_C) {
343                 pcwd_get_firmware();
344                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port "
345                         "0x%04x (Firmware version: %s)\n",
346                         pcwd_private.io_addr, pcwd_private.fw_ver_str);
347                 option_switches = pcwd_get_option_switches();
348                 printk(KERN_INFO PFX "Option switches (0x%02x): "
349                         "Temperature Reset Enable=%s, Power On Delay=%s\n",
350                         option_switches,
351                         ((option_switches & 0x10) ? "ON" : "OFF"),
352                         ((option_switches & 0x08) ? "ON" : "OFF"));
353
354                 /* Reprogram internal heartbeat to 2 seconds */
355                 if (set_command_mode()) {
356                         send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
357                         unset_command_mode();
358                 }
359         }
360
361         if (pcwd_private.supports_temp)
362                 printk(KERN_INFO PFX "Temperature Option Detected\n");
363
364         if (pcwd_private.boot_status & WDIOF_CARDRESET)
365                 printk(KERN_INFO PFX
366                         "Previous reboot was caused by the card\n");
367
368         if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
369                 printk(KERN_EMERG PFX
370                         "Card senses a CPU Overheat. Panicking!\n");
371                 printk(KERN_EMERG PFX
372                         "CPU Overheat\n");
373         }
374
375         if (pcwd_private.boot_status == 0)
376                 printk(KERN_INFO PFX
377                         "No previous trip detected - Cold boot or reset\n");
378 }
379
380 static void pcwd_timer_ping(unsigned long data)
381 {
382         int wdrst_stat;
383
384         /* If we got a heartbeat pulse within the WDT_INTERVAL
385          * we agree to ping the WDT */
386         if (time_before(jiffies, pcwd_private.next_heartbeat)) {
387                 /* Ping the watchdog */
388                 spin_lock(&pcwd_private.io_lock);
389                 if (pcwd_private.revision == PCWD_REVISION_A) {
390                         /*  Rev A cards are reset by setting the
391                             WD_WDRST bit in register 1 */
392                         wdrst_stat = inb_p(pcwd_private.io_addr);
393                         wdrst_stat &= 0x0F;
394                         wdrst_stat |= WD_WDRST;
395
396                         outb_p(wdrst_stat, pcwd_private.io_addr + 1);
397                 } else {
398                         /* Re-trigger watchdog by writing to port 0 */
399                         outb_p(0x00, pcwd_private.io_addr);
400                 }
401
402                 /* Re-set the timer interval */
403                 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
404
405                 spin_unlock(&pcwd_private.io_lock);
406         } else {
407                 printk(KERN_WARNING PFX
408                         "Heartbeat lost! Will not ping the watchdog\n");
409         }
410 }
411
412 static int pcwd_start(void)
413 {
414         int stat_reg;
415
416         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
417
418         /* Start the timer */
419         mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
420
421         /* Enable the port */
422         if (pcwd_private.revision == PCWD_REVISION_C) {
423                 spin_lock(&pcwd_private.io_lock);
424                 outb_p(0x00, pcwd_private.io_addr + 3);
425                 udelay(ISA_COMMAND_TIMEOUT);
426                 stat_reg = inb_p(pcwd_private.io_addr + 2);
427                 spin_unlock(&pcwd_private.io_lock);
428                 if (stat_reg & WD_WDIS) {
429                         printk(KERN_INFO PFX "Could not start watchdog\n");
430                         return -EIO;
431                 }
432         }
433
434         if (debug >= VERBOSE)
435                 printk(KERN_DEBUG PFX "Watchdog started\n");
436
437         return 0;
438 }
439
440 static int pcwd_stop(void)
441 {
442         int stat_reg;
443
444         /* Stop the timer */
445         del_timer(&pcwd_private.timer);
446
447         /*  Disable the board  */
448         if (pcwd_private.revision == PCWD_REVISION_C) {
449                 spin_lock(&pcwd_private.io_lock);
450                 outb_p(0xA5, pcwd_private.io_addr + 3);
451                 udelay(ISA_COMMAND_TIMEOUT);
452                 outb_p(0xA5, pcwd_private.io_addr + 3);
453                 udelay(ISA_COMMAND_TIMEOUT);
454                 stat_reg = inb_p(pcwd_private.io_addr + 2);
455                 spin_unlock(&pcwd_private.io_lock);
456                 if ((stat_reg & WD_WDIS) == 0) {
457                         printk(KERN_INFO PFX "Could not stop watchdog\n");
458                         return -EIO;
459                 }
460         }
461
462         if (debug >= VERBOSE)
463                 printk(KERN_DEBUG PFX "Watchdog stopped\n");
464
465         return 0;
466 }
467
468 static int pcwd_keepalive(void)
469 {
470         /* user land ping */
471         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
472
473         if (debug >= DEBUG)
474                 printk(KERN_DEBUG PFX "Watchdog keepalive signal send\n");
475
476         return 0;
477 }
478
479 static int pcwd_set_heartbeat(int t)
480 {
481         if (t < 2 || t > 7200) /* arbitrary upper limit */
482                 return -EINVAL;
483
484         heartbeat = t;
485
486         if (debug >= VERBOSE)
487                 printk(KERN_DEBUG PFX "New heartbeat: %d\n",
488                        heartbeat);
489
490         return 0;
491 }
492
493 static int pcwd_get_status(int *status)
494 {
495         int control_status;
496
497         *status = 0;
498         spin_lock(&pcwd_private.io_lock);
499         if (pcwd_private.revision == PCWD_REVISION_A)
500                 /* Rev A cards return status information from
501                  * the base register, which is used for the
502                  * temperature in other cards. */
503                 control_status = inb(pcwd_private.io_addr);
504         else {
505                 /* Rev C cards return card status in the base
506                  * address + 1 register. And use different bits
507                  * to indicate a card initiated reset, and an
508                  * over-temperature condition. And the reboot
509                  * status can be reset. */
510                 control_status = inb(pcwd_private.io_addr + 1);
511         }
512         spin_unlock(&pcwd_private.io_lock);
513
514         if (pcwd_private.revision == PCWD_REVISION_A) {
515                 if (control_status & WD_WDRST)
516                         *status |= WDIOF_CARDRESET;
517
518                 if (control_status & WD_T110) {
519                         *status |= WDIOF_OVERHEAT;
520                         if (temp_panic) {
521                                 printk(KERN_INFO PFX
522                                         "Temperature overheat trip!\n");
523                                 kernel_power_off();
524                         }
525                 }
526         } else {
527                 if (control_status & WD_REVC_WTRP)
528                         *status |= WDIOF_CARDRESET;
529
530                 if (control_status & WD_REVC_TTRP) {
531                         *status |= WDIOF_OVERHEAT;
532                         if (temp_panic) {
533                                 printk(KERN_INFO PFX
534                                         "Temperature overheat trip!\n");
535                                 kernel_power_off();
536                         }
537                 }
538         }
539
540         return 0;
541 }
542
543 static int pcwd_clear_status(void)
544 {
545         int control_status;
546
547         if (pcwd_private.revision == PCWD_REVISION_C) {
548                 spin_lock(&pcwd_private.io_lock);
549
550                 if (debug >= VERBOSE)
551                         printk(KERN_INFO PFX
552                                         "clearing watchdog trip status\n");
553
554                 control_status = inb_p(pcwd_private.io_addr + 1);
555
556                 if (debug >= DEBUG) {
557                         printk(KERN_DEBUG PFX "status was: 0x%02x\n",
558                                 control_status);
559                         printk(KERN_DEBUG PFX "sending: 0x%02x\n",
560                                 (control_status & WD_REVC_R2DS));
561                 }
562
563                 /* clear reset status & Keep Relay 2 disable state as it is */
564                 outb_p((control_status & WD_REVC_R2DS),
565                                                 pcwd_private.io_addr + 1);
566
567                 spin_unlock(&pcwd_private.io_lock);
568         }
569         return 0;
570 }
571
572 static int pcwd_get_temperature(int *temperature)
573 {
574         /* check that port 0 gives temperature info and no command results */
575         if (pcwd_private.command_mode)
576                 return -1;
577
578         *temperature = 0;
579         if (!pcwd_private.supports_temp)
580                 return -ENODEV;
581
582         /*
583          * Convert celsius to fahrenheit, since this was
584          * the decided 'standard' for this return value.
585          */
586         spin_lock(&pcwd_private.io_lock);
587         *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
588         spin_unlock(&pcwd_private.io_lock);
589
590         if (debug >= DEBUG) {
591                 printk(KERN_DEBUG PFX "temperature is: %d F\n",
592                         *temperature);
593         }
594
595         return 0;
596 }
597
598 /*
599  *      /dev/watchdog handling
600  */
601
602 static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
603 {
604         int rv;
605         int status;
606         int temperature;
607         int new_heartbeat;
608         int __user *argp = (int __user *)arg;
609         static const struct watchdog_info ident = {
610                 .options =              WDIOF_OVERHEAT |
611                                         WDIOF_CARDRESET |
612                                         WDIOF_KEEPALIVEPING |
613                                         WDIOF_SETTIMEOUT |
614                                         WDIOF_MAGICCLOSE,
615                 .firmware_version =     1,
616                 .identity =             "PCWD",
617         };
618
619         switch (cmd) {
620         case WDIOC_GETSUPPORT:
621                 if (copy_to_user(argp, &ident, sizeof(ident)))
622                         return -EFAULT;
623                 return 0;
624
625         case WDIOC_GETSTATUS:
626                 pcwd_get_status(&status);
627                 return put_user(status, argp);
628
629         case WDIOC_GETBOOTSTATUS:
630                 return put_user(pcwd_private.boot_status, argp);
631
632         case WDIOC_GETTEMP:
633                 if (pcwd_get_temperature(&temperature))
634                         return -EFAULT;
635
636                 return put_user(temperature, argp);
637
638         case WDIOC_SETOPTIONS:
639                 if (pcwd_private.revision == PCWD_REVISION_C) {
640                         if (get_user(rv, argp))
641                                 return -EFAULT;
642
643                         if (rv & WDIOS_DISABLECARD) {
644                                 status = pcwd_stop();
645                                 if (status < 0)
646                                         return status;
647                         }
648                         if (rv & WDIOS_ENABLECARD) {
649                                 status = pcwd_start();
650                                 if (status < 0)
651                                         return status;
652                         }
653                         if (rv & WDIOS_TEMPPANIC)
654                                 temp_panic = 1;
655                 }
656                 return -EINVAL;
657
658         case WDIOC_KEEPALIVE:
659                 pcwd_keepalive();
660                 return 0;
661
662         case WDIOC_SETTIMEOUT:
663                 if (get_user(new_heartbeat, argp))
664                         return -EFAULT;
665
666                 if (pcwd_set_heartbeat(new_heartbeat))
667                         return -EINVAL;
668
669                 pcwd_keepalive();
670                 /* Fall */
671
672         case WDIOC_GETTIMEOUT:
673                 return put_user(heartbeat, argp);
674
675         default:
676                 return -ENOTTY;
677         }
678
679         return 0;
680 }
681
682 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
683                           loff_t *ppos)
684 {
685         if (len) {
686                 if (!nowayout) {
687                         size_t i;
688
689                         /* In case it was set long ago */
690                         expect_close = 0;
691
692                         for (i = 0; i != len; i++) {
693                                 char c;
694
695                                 if (get_user(c, buf + i))
696                                         return -EFAULT;
697                                 if (c == 'V')
698                                         expect_close = 42;
699                         }
700                 }
701                 pcwd_keepalive();
702         }
703         return len;
704 }
705
706 static int pcwd_open(struct inode *inode, struct file *file)
707 {
708         if (test_and_set_bit(0, &open_allowed))
709                 return -EBUSY;
710         if (nowayout)
711                 __module_get(THIS_MODULE);
712         /* Activate */
713         pcwd_start();
714         pcwd_keepalive();
715         return nonseekable_open(inode, file);
716 }
717
718 static int pcwd_close(struct inode *inode, struct file *file)
719 {
720         if (expect_close == 42)
721                 pcwd_stop();
722         else {
723                 printk(KERN_CRIT PFX
724                         "Unexpected close, not stopping watchdog!\n");
725                 pcwd_keepalive();
726         }
727         expect_close = 0;
728         clear_bit(0, &open_allowed);
729         return 0;
730 }
731
732 /*
733  *      /dev/temperature handling
734  */
735
736 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
737                          loff_t *ppos)
738 {
739         int temperature;
740
741         if (pcwd_get_temperature(&temperature))
742                 return -EFAULT;
743
744         if (copy_to_user(buf, &temperature, 1))
745                 return -EFAULT;
746
747         return 1;
748 }
749
750 static int pcwd_temp_open(struct inode *inode, struct file *file)
751 {
752         if (!pcwd_private.supports_temp)
753                 return -ENODEV;
754
755         return nonseekable_open(inode, file);
756 }
757
758 static int pcwd_temp_close(struct inode *inode, struct file *file)
759 {
760         return 0;
761 }
762
763 /*
764  *      Kernel Interfaces
765  */
766
767 static const struct file_operations pcwd_fops = {
768         .owner          = THIS_MODULE,
769         .llseek         = no_llseek,
770         .write          = pcwd_write,
771         .unlocked_ioctl = pcwd_ioctl,
772         .open           = pcwd_open,
773         .release        = pcwd_close,
774 };
775
776 static struct miscdevice pcwd_miscdev = {
777         .minor =        WATCHDOG_MINOR,
778         .name =         "watchdog",
779         .fops =         &pcwd_fops,
780 };
781
782 static const struct file_operations pcwd_temp_fops = {
783         .owner          = THIS_MODULE,
784         .llseek         = no_llseek,
785         .read           = pcwd_temp_read,
786         .open           = pcwd_temp_open,
787         .release        = pcwd_temp_close,
788 };
789
790 static struct miscdevice temp_miscdev = {
791         .minor =        TEMP_MINOR,
792         .name =         "temperature",
793         .fops =         &pcwd_temp_fops,
794 };
795
796 /*
797  *      Init & exit routines
798  */
799
800 static inline int get_revision(void)
801 {
802         int r = PCWD_REVISION_C;
803
804         spin_lock(&pcwd_private.io_lock);
805         /* REV A cards use only 2 io ports; test
806          * presumes a floating bus reads as 0xff. */
807         if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
808             (inb(pcwd_private.io_addr + 3) == 0xFF))
809                 r = PCWD_REVISION_A;
810         spin_unlock(&pcwd_private.io_lock);
811
812         return r;
813 }
814
815 /*
816  *  The ISA cards have a heartbeat bit in one of the registers, which
817  *  register is card dependent.  The heartbeat bit is monitored, and if
818  *  found, is considered proof that a Berkshire card has been found.
819  *  The initial rate is once per second at board start up, then twice
820  *  per second for normal operation.
821  */
822 static int __devinit pcwd_isa_match(struct device *dev, unsigned int id)
823 {
824         int base_addr = pcwd_ioports[id];
825         int port0, last_port0;  /* Reg 0, in case it's REV A */
826         int port1, last_port1;  /* Register 1 for REV C cards */
827         int i;
828         int retval;
829
830         if (debug >= DEBUG)
831                 printk(KERN_DEBUG PFX "pcwd_isa_match id=%d\n",
832                         id);
833
834         if (!request_region(base_addr, 4, "PCWD")) {
835                 printk(KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
836                 return 0;
837         }
838
839         retval = 0;
840
841         port0 = inb_p(base_addr);       /* For REV A boards */
842         port1 = inb_p(base_addr + 1);   /* For REV C boards */
843         if (port0 != 0xff || port1 != 0xff) {
844                 /* Not an 'ff' from a floating bus, so must be a card! */
845                 for (i = 0; i < 4; ++i) {
846
847                         msleep(500);
848
849                         last_port0 = port0;
850                         last_port1 = port1;
851
852                         port0 = inb_p(base_addr);
853                         port1 = inb_p(base_addr + 1);
854
855                         /* Has either hearbeat bit changed?  */
856                         if ((port0 ^ last_port0) & WD_HRTBT ||
857                             (port1 ^ last_port1) & WD_REVC_HRBT) {
858                                 retval = 1;
859                                 break;
860                         }
861                 }
862         }
863         release_region(base_addr, 4);
864
865         return retval;
866 }
867
868 static int __devinit pcwd_isa_probe(struct device *dev, unsigned int id)
869 {
870         int ret;
871
872         if (debug >= DEBUG)
873                 printk(KERN_DEBUG PFX "pcwd_isa_probe id=%d\n",
874                         id);
875
876         cards_found++;
877         if (cards_found == 1)
878                 printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n",
879                                                         WATCHDOG_VERSION);
880
881         if (cards_found > 1) {
882                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
883                 return -ENODEV;
884         }
885
886         if (pcwd_ioports[id] == 0x0000) {
887                 printk(KERN_ERR PFX "No I/O-Address for card detected\n");
888                 return -ENODEV;
889         }
890         pcwd_private.io_addr = pcwd_ioports[id];
891
892         spin_lock_init(&pcwd_private.io_lock);
893
894         /* Check card's revision */
895         pcwd_private.revision = get_revision();
896
897         if (!request_region(pcwd_private.io_addr,
898                 (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
899                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
900                         pcwd_private.io_addr);
901                 ret = -EIO;
902                 goto error_request_region;
903         }
904
905         /* Initial variables */
906         pcwd_private.supports_temp = 0;
907         temp_panic = 0;
908         pcwd_private.boot_status = 0x0000;
909
910         /* get the boot_status */
911         pcwd_get_status(&pcwd_private.boot_status);
912
913         /* clear the "card caused reboot" flag */
914         pcwd_clear_status();
915
916         setup_timer(&pcwd_private.timer, pcwd_timer_ping, 0);
917
918         /*  Disable the board  */
919         pcwd_stop();
920
921         /*  Check whether or not the card supports the temperature device */
922         pcwd_check_temperature_support();
923
924         /* Show info about the card itself */
925         pcwd_show_card_info();
926
927         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
928         if (heartbeat == 0)
929                 heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
930
931         /* Check that the heartbeat value is within it's range;
932            if not reset to the default */
933         if (pcwd_set_heartbeat(heartbeat)) {
934                 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
935                 printk(KERN_INFO PFX
936                   "heartbeat value must be 2 <= heartbeat <= 7200, using %d\n",
937                                                         WATCHDOG_HEARTBEAT);
938         }
939
940         if (pcwd_private.supports_temp) {
941                 ret = misc_register(&temp_miscdev);
942                 if (ret) {
943                         printk(KERN_ERR PFX
944                             "cannot register miscdev on minor=%d (err=%d)\n",
945                                                         TEMP_MINOR, ret);
946                         goto error_misc_register_temp;
947                 }
948         }
949
950         ret = misc_register(&pcwd_miscdev);
951         if (ret) {
952                 printk(KERN_ERR PFX
953                         "cannot register miscdev on minor=%d (err=%d)\n",
954                                         WATCHDOG_MINOR, ret);
955                 goto error_misc_register_watchdog;
956         }
957
958         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
959                 heartbeat, nowayout);
960
961         return 0;
962
963 error_misc_register_watchdog:
964         if (pcwd_private.supports_temp)
965                 misc_deregister(&temp_miscdev);
966 error_misc_register_temp:
967         release_region(pcwd_private.io_addr,
968                         (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
969 error_request_region:
970         pcwd_private.io_addr = 0x0000;
971         cards_found--;
972         return ret;
973 }
974
975 static int __devexit pcwd_isa_remove(struct device *dev, unsigned int id)
976 {
977         if (debug >= DEBUG)
978                 printk(KERN_DEBUG PFX "pcwd_isa_remove id=%d\n",
979                         id);
980
981         if (!pcwd_private.io_addr)
982                 return 1;
983
984         /*  Disable the board  */
985         if (!nowayout)
986                 pcwd_stop();
987
988         /* Deregister */
989         misc_deregister(&pcwd_miscdev);
990         if (pcwd_private.supports_temp)
991                 misc_deregister(&temp_miscdev);
992         release_region(pcwd_private.io_addr,
993                         (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
994         pcwd_private.io_addr = 0x0000;
995         cards_found--;
996
997         return 0;
998 }
999
1000 static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
1001 {
1002         if (debug >= DEBUG)
1003                 printk(KERN_DEBUG PFX "pcwd_isa_shutdown id=%d\n",
1004                         id);
1005
1006         pcwd_stop();
1007 }
1008
1009 static struct isa_driver pcwd_isa_driver = {
1010         .match          = pcwd_isa_match,
1011         .probe          = pcwd_isa_probe,
1012         .remove         = __devexit_p(pcwd_isa_remove),
1013         .shutdown       = pcwd_isa_shutdown,
1014         .driver         = {
1015                 .owner  = THIS_MODULE,
1016                 .name   = WATCHDOG_NAME,
1017         },
1018 };
1019
1020 static int __init pcwd_init_module(void)
1021 {
1022         return isa_register_driver(&pcwd_isa_driver, PCWD_ISA_NR_CARDS);
1023 }
1024
1025 static void __exit pcwd_cleanup_module(void)
1026 {
1027         isa_unregister_driver(&pcwd_isa_driver);
1028         printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
1029 }
1030
1031 module_init(pcwd_init_module);
1032 module_exit(pcwd_cleanup_module);
1033
1034 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, "
1035                 "Wim Van Sebroeck <wim@iguana.be>");
1036 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1037 MODULE_VERSION(WATCHDOG_VERSION);
1038 MODULE_LICENSE("GPL");
1039 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1040 MODULE_ALIAS_MISCDEV(TEMP_MINOR);