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pcwd.c
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1 /*
2  * PC Watchdog Driver
3  * by Ken Hollis ([email protected])
4  *
5  * Permission granted from Simon Machell ([email protected])
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 <[email protected]>.
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 <[email protected]>]
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 <[email protected]>
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
55 
56 #include <linux/module.h> /* For module specific items */
57 #include <linux/moduleparam.h> /* For new moduleparam's */
58 #include <linux/types.h> /* For standard types (like size_t) */
59 #include <linux/errno.h> /* For the -ENODEV/... values */
60 #include <linux/kernel.h> /* For printk/panic/... */
61 #include <linux/delay.h> /* For mdelay function */
62 #include <linux/timer.h> /* For timer related operations */
63 #include <linux/jiffies.h> /* For jiffies stuff */
64 #include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
65 #include <linux/watchdog.h> /* For the watchdog specific items */
66 #include <linux/reboot.h> /* For kernel_power_off() */
67 #include <linux/init.h> /* For __init/__exit/... */
68 #include <linux/fs.h> /* For file operations */
69 #include <linux/isa.h> /* For isa devices */
70 #include <linux/ioport.h> /* For io-port access */
71 #include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
72 #include <linux/uaccess.h> /* For copy_to_user/put_user/... */
73 #include <linux/io.h> /* For inb/outb/... */
74 
75 /* Module and version information */
76 #define WATCHDOG_VERSION "1.20"
77 #define WATCHDOG_DATE "18 Feb 2007"
78 #define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
79 #define WATCHDOG_NAME "pcwd"
80 #define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION "\n"
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. "
204  "(2 <= heartbeat <= 7200 or 0=delay-time from dip-switches, default="
205  __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
206 
207 static bool nowayout = WATCHDOG_NOWAYOUT;
208 module_param(nowayout, bool, 0);
209 MODULE_PARM_DESC(nowayout,
210  "Watchdog cannot be stopped once started (default="
211  __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
212 
213 /*
214  * Internal functions
215  */
216 
217 static int send_isa_command(int cmd)
218 {
219  int i;
220  int control_status;
221  int port0, last_port0; /* Double read for stabilising */
222 
223  if (debug >= DEBUG)
224  pr_debug("sending following data cmd=0x%02x\n", 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  pr_debug("received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
244  cmd, port0, last_port0);
245 
246  return port0;
247 }
248 
249 static int set_command_mode(void)
250 {
251  int i, found = 0, count = 0;
252 
253  /* Set the card into command mode */
254  spin_lock(&pcwd_private.io_lock);
255  while ((!found) && (count < 3)) {
256  i = send_isa_command(CMD_ISA_IDLE);
257 
258  if (i == 0x00)
259  found = 1;
260  else if (i == 0xF3) {
261  /* Card does not like what we've done to it */
262  outb_p(0x00, pcwd_private.io_addr + 2);
263  udelay(1200); /* Spec says wait 1ms */
264  outb_p(0x00, pcwd_private.io_addr + 2);
265  udelay(ISA_COMMAND_TIMEOUT);
266  }
267  count++;
268  }
269  spin_unlock(&pcwd_private.io_lock);
270  pcwd_private.command_mode = found;
271 
272  if (debug >= DEBUG)
273  pr_debug("command_mode=%d\n", 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  pr_debug("command_mode=%d\n", pcwd_private.command_mode);
290 }
291 
292 static inline void pcwd_check_temperature_support(void)
293 {
294  if (inb(pcwd_private.io_addr) != 0xF0)
295  pcwd_private.supports_temp = 1;
296 }
297 
298 static inline void pcwd_get_firmware(void)
299 {
300  int one, ten, hund, minor;
301 
302  strcpy(pcwd_private.fw_ver_str, "ERROR");
303 
304  if (set_command_mode()) {
305  one = send_isa_command(CMD_ISA_VERSION_INTEGER);
306  ten = send_isa_command(CMD_ISA_VERSION_TENTH);
307  hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
308  minor = send_isa_command(CMD_ISA_VERSION_MINOR);
309  sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c",
310  one, ten, hund, minor);
311  }
312  unset_command_mode();
313 
314  return;
315 }
316 
317 static inline int pcwd_get_option_switches(void)
318 {
319  int option_switches = 0;
320 
321  if (set_command_mode()) {
322  /* Get switch settings */
323  option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
324  }
325 
326  unset_command_mode();
327  return option_switches;
328 }
329 
330 static void pcwd_show_card_info(void)
331 {
332  int option_switches;
333 
334  /* Get some extra info from the hardware (in command/debug/diag mode) */
335  if (pcwd_private.revision == PCWD_REVISION_A)
336  pr_info("ISA-PC Watchdog (REV.A) detected at port 0x%04x\n",
337  pcwd_private.io_addr);
338  else if (pcwd_private.revision == PCWD_REVISION_C) {
339  pcwd_get_firmware();
340  pr_info("ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
341  pcwd_private.io_addr, pcwd_private.fw_ver_str);
342  option_switches = pcwd_get_option_switches();
343  pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
344  option_switches,
345  ((option_switches & 0x10) ? "ON" : "OFF"),
346  ((option_switches & 0x08) ? "ON" : "OFF"));
347 
348  /* Reprogram internal heartbeat to 2 seconds */
349  if (set_command_mode()) {
350  send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
351  unset_command_mode();
352  }
353  }
354 
355  if (pcwd_private.supports_temp)
356  pr_info("Temperature Option Detected\n");
357 
358  if (pcwd_private.boot_status & WDIOF_CARDRESET)
359  pr_info("Previous reboot was caused by the card\n");
360 
361  if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
362  pr_emerg("Card senses a CPU Overheat. Panicking!\n");
363  pr_emerg("CPU Overheat\n");
364  }
365 
366  if (pcwd_private.boot_status == 0)
367  pr_info("No previous trip detected - Cold boot or reset\n");
368 }
369 
370 static void pcwd_timer_ping(unsigned long data)
371 {
372  int wdrst_stat;
373 
374  /* If we got a heartbeat pulse within the WDT_INTERVAL
375  * we agree to ping the WDT */
376  if (time_before(jiffies, pcwd_private.next_heartbeat)) {
377  /* Ping the watchdog */
378  spin_lock(&pcwd_private.io_lock);
379  if (pcwd_private.revision == PCWD_REVISION_A) {
380  /* Rev A cards are reset by setting the
381  WD_WDRST bit in register 1 */
382  wdrst_stat = inb_p(pcwd_private.io_addr);
383  wdrst_stat &= 0x0F;
384  wdrst_stat |= WD_WDRST;
385 
386  outb_p(wdrst_stat, pcwd_private.io_addr + 1);
387  } else {
388  /* Re-trigger watchdog by writing to port 0 */
389  outb_p(0x00, pcwd_private.io_addr);
390  }
391 
392  /* Re-set the timer interval */
393  mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
394 
395  spin_unlock(&pcwd_private.io_lock);
396  } else {
397  pr_warn("Heartbeat lost! Will not ping the watchdog\n");
398  }
399 }
400 
401 static int pcwd_start(void)
402 {
403  int stat_reg;
404 
405  pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
406 
407  /* Start the timer */
408  mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
409 
410  /* Enable the port */
411  if (pcwd_private.revision == PCWD_REVISION_C) {
412  spin_lock(&pcwd_private.io_lock);
413  outb_p(0x00, pcwd_private.io_addr + 3);
414  udelay(ISA_COMMAND_TIMEOUT);
415  stat_reg = inb_p(pcwd_private.io_addr + 2);
416  spin_unlock(&pcwd_private.io_lock);
417  if (stat_reg & WD_WDIS) {
418  pr_info("Could not start watchdog\n");
419  return -EIO;
420  }
421  }
422 
423  if (debug >= VERBOSE)
424  pr_debug("Watchdog started\n");
425 
426  return 0;
427 }
428 
429 static int pcwd_stop(void)
430 {
431  int stat_reg;
432 
433  /* Stop the timer */
434  del_timer(&pcwd_private.timer);
435 
436  /* Disable the board */
437  if (pcwd_private.revision == PCWD_REVISION_C) {
438  spin_lock(&pcwd_private.io_lock);
439  outb_p(0xA5, pcwd_private.io_addr + 3);
440  udelay(ISA_COMMAND_TIMEOUT);
441  outb_p(0xA5, pcwd_private.io_addr + 3);
442  udelay(ISA_COMMAND_TIMEOUT);
443  stat_reg = inb_p(pcwd_private.io_addr + 2);
444  spin_unlock(&pcwd_private.io_lock);
445  if ((stat_reg & WD_WDIS) == 0) {
446  pr_info("Could not stop watchdog\n");
447  return -EIO;
448  }
449  }
450 
451  if (debug >= VERBOSE)
452  pr_debug("Watchdog stopped\n");
453 
454  return 0;
455 }
456 
457 static int pcwd_keepalive(void)
458 {
459  /* user land ping */
460  pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
461 
462  if (debug >= DEBUG)
463  pr_debug("Watchdog keepalive signal send\n");
464 
465  return 0;
466 }
467 
468 static int pcwd_set_heartbeat(int t)
469 {
470  if (t < 2 || t > 7200) /* arbitrary upper limit */
471  return -EINVAL;
472 
473  heartbeat = t;
474 
475  if (debug >= VERBOSE)
476  pr_debug("New heartbeat: %d\n", heartbeat);
477 
478  return 0;
479 }
480 
481 static int pcwd_get_status(int *status)
482 {
483  int control_status;
484 
485  *status = 0;
486  spin_lock(&pcwd_private.io_lock);
487  if (pcwd_private.revision == PCWD_REVISION_A)
488  /* Rev A cards return status information from
489  * the base register, which is used for the
490  * temperature in other cards. */
491  control_status = inb(pcwd_private.io_addr);
492  else {
493  /* Rev C cards return card status in the base
494  * address + 1 register. And use different bits
495  * to indicate a card initiated reset, and an
496  * over-temperature condition. And the reboot
497  * status can be reset. */
498  control_status = inb(pcwd_private.io_addr + 1);
499  }
500  spin_unlock(&pcwd_private.io_lock);
501 
502  if (pcwd_private.revision == PCWD_REVISION_A) {
503  if (control_status & WD_WDRST)
504  *status |= WDIOF_CARDRESET;
505 
506  if (control_status & WD_T110) {
507  *status |= WDIOF_OVERHEAT;
508  if (temp_panic) {
509  pr_info("Temperature overheat trip!\n");
510  kernel_power_off();
511  }
512  }
513  } else {
514  if (control_status & WD_REVC_WTRP)
515  *status |= WDIOF_CARDRESET;
516 
517  if (control_status & WD_REVC_TTRP) {
518  *status |= WDIOF_OVERHEAT;
519  if (temp_panic) {
520  pr_info("Temperature overheat trip!\n");
521  kernel_power_off();
522  }
523  }
524  }
525 
526  return 0;
527 }
528 
529 static int pcwd_clear_status(void)
530 {
531  int control_status;
532 
533  if (pcwd_private.revision == PCWD_REVISION_C) {
534  spin_lock(&pcwd_private.io_lock);
535 
536  if (debug >= VERBOSE)
537  pr_info("clearing watchdog trip status\n");
538 
539  control_status = inb_p(pcwd_private.io_addr + 1);
540 
541  if (debug >= DEBUG) {
542  pr_debug("status was: 0x%02x\n", control_status);
543  pr_debug("sending: 0x%02x\n",
544  (control_status & WD_REVC_R2DS));
545  }
546 
547  /* clear reset status & Keep Relay 2 disable state as it is */
548  outb_p((control_status & WD_REVC_R2DS),
549  pcwd_private.io_addr + 1);
550 
551  spin_unlock(&pcwd_private.io_lock);
552  }
553  return 0;
554 }
555 
556 static int pcwd_get_temperature(int *temperature)
557 {
558  /* check that port 0 gives temperature info and no command results */
559  if (pcwd_private.command_mode)
560  return -1;
561 
562  *temperature = 0;
563  if (!pcwd_private.supports_temp)
564  return -ENODEV;
565 
566  /*
567  * Convert celsius to fahrenheit, since this was
568  * the decided 'standard' for this return value.
569  */
570  spin_lock(&pcwd_private.io_lock);
571  *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
572  spin_unlock(&pcwd_private.io_lock);
573 
574  if (debug >= DEBUG) {
575  pr_debug("temperature is: %d F\n", *temperature);
576  }
577 
578  return 0;
579 }
580 
581 /*
582  * /dev/watchdog handling
583  */
584 
585 static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
586 {
587  int rv;
588  int status;
589  int temperature;
590  int new_heartbeat;
591  int __user *argp = (int __user *)arg;
592  static const struct watchdog_info ident = {
593  .options = WDIOF_OVERHEAT |
594  WDIOF_CARDRESET |
595  WDIOF_KEEPALIVEPING |
596  WDIOF_SETTIMEOUT |
597  WDIOF_MAGICCLOSE,
598  .firmware_version = 1,
599  .identity = "PCWD",
600  };
601 
602  switch (cmd) {
603  case WDIOC_GETSUPPORT:
604  if (copy_to_user(argp, &ident, sizeof(ident)))
605  return -EFAULT;
606  return 0;
607 
608  case WDIOC_GETSTATUS:
609  pcwd_get_status(&status);
610  return put_user(status, argp);
611 
612  case WDIOC_GETBOOTSTATUS:
613  return put_user(pcwd_private.boot_status, argp);
614 
615  case WDIOC_GETTEMP:
616  if (pcwd_get_temperature(&temperature))
617  return -EFAULT;
618 
619  return put_user(temperature, argp);
620 
621  case WDIOC_SETOPTIONS:
622  if (pcwd_private.revision == PCWD_REVISION_C) {
623  if (get_user(rv, argp))
624  return -EFAULT;
625 
626  if (rv & WDIOS_DISABLECARD) {
627  status = pcwd_stop();
628  if (status < 0)
629  return status;
630  }
631  if (rv & WDIOS_ENABLECARD) {
632  status = pcwd_start();
633  if (status < 0)
634  return status;
635  }
636  if (rv & WDIOS_TEMPPANIC)
637  temp_panic = 1;
638  }
639  return -EINVAL;
640 
641  case WDIOC_KEEPALIVE:
642  pcwd_keepalive();
643  return 0;
644 
645  case WDIOC_SETTIMEOUT:
646  if (get_user(new_heartbeat, argp))
647  return -EFAULT;
648 
649  if (pcwd_set_heartbeat(new_heartbeat))
650  return -EINVAL;
651 
652  pcwd_keepalive();
653  /* Fall */
654 
655  case WDIOC_GETTIMEOUT:
656  return put_user(heartbeat, argp);
657 
658  default:
659  return -ENOTTY;
660  }
661 
662  return 0;
663 }
664 
665 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
666  loff_t *ppos)
667 {
668  if (len) {
669  if (!nowayout) {
670  size_t i;
671 
672  /* In case it was set long ago */
673  expect_close = 0;
674 
675  for (i = 0; i != len; i++) {
676  char c;
677 
678  if (get_user(c, buf + i))
679  return -EFAULT;
680  if (c == 'V')
681  expect_close = 42;
682  }
683  }
684  pcwd_keepalive();
685  }
686  return len;
687 }
688 
689 static int pcwd_open(struct inode *inode, struct file *file)
690 {
691  if (test_and_set_bit(0, &open_allowed))
692  return -EBUSY;
693  if (nowayout)
694  __module_get(THIS_MODULE);
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  pr_crit("Unexpected close, not stopping watchdog!\n");
707  pcwd_keepalive();
708  }
709  expect_close = 0;
710  clear_bit(0, &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  .unlocked_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  pr_debug("pcwd_isa_match id=%d\n", id);
814 
815  if (!request_region(base_addr, 4, "PCWD")) {
816  pr_info("Port 0x%04x unavailable\n", base_addr);
817  return 0;
818  }
819 
820  retval = 0;
821 
822  port0 = inb_p(base_addr); /* For REV A boards */
823  port1 = inb_p(base_addr + 1); /* For REV C boards */
824  if (port0 != 0xff || port1 != 0xff) {
825  /* Not an 'ff' from a floating bus, so must be a card! */
826  for (i = 0; i < 4; ++i) {
827 
828  msleep(500);
829 
830  last_port0 = port0;
831  last_port1 = port1;
832 
833  port0 = inb_p(base_addr);
834  port1 = inb_p(base_addr + 1);
835 
836  /* Has either hearbeat bit changed? */
837  if ((port0 ^ last_port0) & WD_HRTBT ||
838  (port1 ^ last_port1) & WD_REVC_HRBT) {
839  retval = 1;
840  break;
841  }
842  }
843  }
844  release_region(base_addr, 4);
845 
846  return retval;
847 }
848 
849 static int __devinit pcwd_isa_probe(struct device *dev, unsigned int id)
850 {
851  int ret;
852 
853  if (debug >= DEBUG)
854  pr_debug("pcwd_isa_probe id=%d\n", id);
855 
856  cards_found++;
857  if (cards_found == 1)
858  pr_info("v%s Ken Hollis ([email protected])\n",
859  WATCHDOG_VERSION);
860 
861  if (cards_found > 1) {
862  pr_err("This driver only supports 1 device\n");
863  return -ENODEV;
864  }
865 
866  if (pcwd_ioports[id] == 0x0000) {
867  pr_err("No I/O-Address for card detected\n");
868  return -ENODEV;
869  }
870  pcwd_private.io_addr = pcwd_ioports[id];
871 
872  spin_lock_init(&pcwd_private.io_lock);
873 
874  /* Check card's revision */
875  pcwd_private.revision = get_revision();
876 
877  if (!request_region(pcwd_private.io_addr,
878  (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
879  pr_err("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;
912  if not reset to the default */
913  if (pcwd_set_heartbeat(heartbeat)) {
914  pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
915  pr_info("heartbeat value must be 2 <= heartbeat <= 7200, using %d\n",
916  WATCHDOG_HEARTBEAT);
917  }
918 
919  if (pcwd_private.supports_temp) {
920  ret = misc_register(&temp_miscdev);
921  if (ret) {
922  pr_err("cannot register miscdev on minor=%d (err=%d)\n",
923  TEMP_MINOR, ret);
924  goto error_misc_register_temp;
925  }
926  }
927 
928  ret = misc_register(&pcwd_miscdev);
929  if (ret) {
930  pr_err("cannot register miscdev on minor=%d (err=%d)\n",
931  WATCHDOG_MINOR, ret);
932  goto error_misc_register_watchdog;
933  }
934 
935  pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
936  heartbeat, nowayout);
937 
938  return 0;
939 
940 error_misc_register_watchdog:
941  if (pcwd_private.supports_temp)
942  misc_deregister(&temp_miscdev);
943 error_misc_register_temp:
944  release_region(pcwd_private.io_addr,
945  (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
946 error_request_region:
947  pcwd_private.io_addr = 0x0000;
948  cards_found--;
949  return ret;
950 }
951 
952 static int __devexit pcwd_isa_remove(struct device *dev, unsigned int id)
953 {
954  if (debug >= DEBUG)
955  pr_debug("pcwd_isa_remove id=%d\n", id);
956 
957  if (!pcwd_private.io_addr)
958  return 1;
959 
960  /* Disable the board */
961  if (!nowayout)
962  pcwd_stop();
963 
964  /* Deregister */
965  misc_deregister(&pcwd_miscdev);
966  if (pcwd_private.supports_temp)
967  misc_deregister(&temp_miscdev);
968  release_region(pcwd_private.io_addr,
969  (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
970  pcwd_private.io_addr = 0x0000;
971  cards_found--;
972 
973  return 0;
974 }
975 
976 static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
977 {
978  if (debug >= DEBUG)
979  pr_debug("pcwd_isa_shutdown id=%d\n", id);
980 
981  pcwd_stop();
982 }
983 
984 static struct isa_driver pcwd_isa_driver = {
985  .match = pcwd_isa_match,
986  .probe = pcwd_isa_probe,
987  .remove = __devexit_p(pcwd_isa_remove),
988  .shutdown = pcwd_isa_shutdown,
989  .driver = {
990  .owner = THIS_MODULE,
991  .name = WATCHDOG_NAME,
992  },
993 };
994 
995 static int __init pcwd_init_module(void)
996 {
997  return isa_register_driver(&pcwd_isa_driver, PCWD_ISA_NR_CARDS);
998 }
999 
1000 static void __exit pcwd_cleanup_module(void)
1001 {
1002  isa_unregister_driver(&pcwd_isa_driver);
1003  pr_info("Watchdog Module Unloaded\n");
1004 }
1005 
1006 module_init(pcwd_init_module);
1007 module_exit(pcwd_cleanup_module);
1008 
1009 MODULE_AUTHOR("Ken Hollis <[email protected]>, "
1010  "Wim Van Sebroeck <[email protected]>");
1011 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1012 MODULE_VERSION(WATCHDOG_VERSION);
1013 MODULE_LICENSE("GPL");
1014 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1015 MODULE_ALIAS_MISCDEV(TEMP_MINOR);
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