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