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#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 struct miscdevice */ 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 99static 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 */ 148static 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 */ 168static int cards_found; 169 170/* internal variables */ 171static unsigned long open_allowed; 172static char expect_close; 173static int temp_panic; 174 175/* this is private data for each ISA-PC watchdog card */ 176static 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 */ 194static int debug = QUIET; 195module_param(debug, int, 0); 196MODULE_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 201static int heartbeat = WATCHDOG_HEARTBEAT; 202module_param(heartbeat, int, 0); 203MODULE_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 207static bool nowayout = WATCHDOG_NOWAYOUT; 208module_param(nowayout, bool, 0); 209MODULE_PARM_DESC(nowayout, 210 "Watchdog cannot be stopped once started (default=" 211 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 212 213/* 214 * Internal functions 215 */ 216 217static 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 249static 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 278static 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 292static inline void pcwd_check_temperature_support(void) 293{ 294 if (inb(pcwd_private.io_addr) != 0xF0) 295 pcwd_private.supports_temp = 1; 296} 297 298static 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 317static 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 330static 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 370static 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 401static 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 429static 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 457static 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 468static 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 481static 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 529static 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 556static 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 585static 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 665static 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 689static 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 701static 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 718static 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 732static 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 740static int pcwd_temp_close(struct inode *inode, struct file *file) 741{ 742 return 0; 743} 744 745/* 746 * Kernel Interfaces 747 */ 748 749static 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 758static struct miscdevice pcwd_miscdev = { 759 .minor = WATCHDOG_MINOR, 760 .name = "watchdog", 761 .fops = &pcwd_fops, 762}; 763 764static 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 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 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 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 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 int 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 976static 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 984static struct isa_driver pcwd_isa_driver = { 985 .match = pcwd_isa_match, 986 .probe = pcwd_isa_probe, 987 .remove = pcwd_isa_remove, 988 .shutdown = pcwd_isa_shutdown, 989 .driver = { 990 .owner = THIS_MODULE, 991 .name = WATCHDOG_NAME, 992 }, 993}; 994 995static int __init pcwd_init_module(void) 996{ 997 return isa_register_driver(&pcwd_isa_driver, PCWD_ISA_NR_CARDS); 998} 999 1000static void __exit pcwd_cleanup_module(void) 1001{ 1002 isa_unregister_driver(&pcwd_isa_driver); 1003 pr_info("Watchdog Module Unloaded\n"); 1004} 1005 1006module_init(pcwd_init_module); 1007module_exit(pcwd_cleanup_module); 1008 1009MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, " 1010 "Wim Van Sebroeck <wim@iguana.be>"); 1011MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver"); 1012MODULE_VERSION(WATCHDOG_VERSION); 1013MODULE_LICENSE("GPL"); 1014