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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * PC Watchdog Driver4 * by Ken Hollis (khollis@bitgate.com)5 *6 * Permission granted from Simon Machell (smachell@berkprod.com)7 * Written for the Linux Kernel, and GPLed by Ken Hollis8 *9 * 960107 Added request_region routines, modulized the whole thing.10 * 960108 Fixed end-of-file pointer (Thanks to Dan Hollis), added11 * 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 for14 * inclusion in Linux 2.0.x kernels, thanks to Alan Cox.15 * 960717 Removed read/seek routines, replaced with ioctl. Also, added16 * check_region command due to Alan's suggestion.17 * 960821 Made changes to compile in newer 2.0.x kernels. Added18 * "cold reboot sense" entry.19 * 960825 Made a few changes to code, deleted some defines and made20 * typedefs to replace them. Made heartbeat reset only available21 * 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 firmware25 * version reporting. Added read routine for temperature.26 * Removed some extra defines, added an autodetect Revision27 * routine.28 * 961006 Revised some documentation, fixed some cosmetic bugs. Made29 * drivers to panic the system if it's overheating at bootup.30 * 961118 Changed some verbiage on some of the output, tidied up31 * 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 handling36 * Michael Meskes <meskes@debian.org>.37 * 980112 Used minor numbers from include/linux/miscdevice.h38 * 990403 Clear reset status after reading control status register in39 * pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]40 * 990605 Made changes to code to support Firmware 1.22a, added41 * 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 override45 * CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>46 * Added timeout module option to override default47 */48 49/*50 * A bells and whistles driver is available from http://www.pcwd.de/51 * More info available at http://www.berkprod.com/ or52 * http://www.pcwatchdog.com/53 */54 55#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt56 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 B85 * are essentially the same types of card, with the exception that B86 * 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 they88 * are no longer in production.)89 */90#define PCWD_REVISION_A 191#define PCWD_REVISION_C 292 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 3100static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };101 102/*103 * These are the defines that describe the control status bits for the104 * 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 by117 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 Select125 (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 1000131 132/* Watchdog's internal commands */133#define CMD_ISA_IDLE 0x00134#define CMD_ISA_VERSION_INTEGER 0x01135#define CMD_ISA_VERSION_TENTH 0x02136#define CMD_ISA_VERSION_HUNDRETH 0x03137#define CMD_ISA_VERSION_MINOR 0x04138#define CMD_ISA_SWITCH_SETTINGS 0x05139#define CMD_ISA_RESET_PC 0x06140#define CMD_ISA_ARM_0 0x07141#define CMD_ISA_ARM_30 0x08142#define CMD_ISA_ARM_60 0x09143#define CMD_ISA_DELAY_TIME_2SECS 0x0A144#define CMD_ISA_DELAY_TIME_4SECS 0x0B145#define CMD_ISA_DELAY_TIME_8SECS 0x0C146#define CMD_ISA_RESET_RELAYS 0x0D147 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 watchdog162 * every ~500ms. We try to set the internal heartbeat of the163 * 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 has181 a temperature device */182 int command_mode; /* Whether or not the card is in183 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 0202static 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 functions216 */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_INTERVAL376 * 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 the382 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 del_timer(&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 from490 * the base register, which is used for the491 * temperature in other cards. */492 control_status = inb(pcwd_private.io_addr);493 else {494 /* Rev C cards return card status in the base495 * address + 1 register. And use different bits496 * to indicate a card initiated reset, and an497 * over-temperature condition. And the reboot498 * 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 was569 * 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 handling584 */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 handling717 */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 Interfaces748 */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 routines780 */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; test788 * 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, which799 * register is card dependent. The heartbeat bit is monitored, and if800 * found, is considered proof that a Berkshire card has been found.801 * The initial rate is once per second at board start up, then twice802 * 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 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 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 (kenji@bitgate.com)\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 <kenji@bitgate.com>, "993 "Wim Van Sebroeck <wim@iguana.be>");994MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");995MODULE_VERSION(WATCHDOG_VERSION);996MODULE_LICENSE("GPL");997