1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * PC Watchdog Driver 4 * 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 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 <meskes@debian.org>. 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 <marc@mbsi.ca>] 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 <Matt_Domsch@dell.com> 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 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 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 .llseek = no_llseek, 753 .write = pcwd_write, 754 .unlocked_ioctl = pcwd_ioctl, 755 .compat_ioctl = compat_ptr_ioctl, 756 .open = pcwd_open, 757 .release = pcwd_close, 758}; 759 760static struct miscdevice pcwd_miscdev = { 761 .minor = WATCHDOG_MINOR, 762 .name = "watchdog", 763 .fops = &pcwd_fops, 764}; 765 766static const struct file_operations pcwd_temp_fops = { 767 .owner = THIS_MODULE, 768 .llseek = no_llseek, 769 .read = pcwd_temp_read, 770 .open = pcwd_temp_open, 771 .release = pcwd_temp_close, 772}; 773 774static struct miscdevice temp_miscdev = { 775 .minor = TEMP_MINOR, 776 .name = "temperature", 777 .fops = &pcwd_temp_fops, 778}; 779 780/* 781 * Init & exit routines 782 */ 783 784static inline int get_revision(void) 785{ 786 int r = PCWD_REVISION_C; 787 788 spin_lock(&pcwd_private.io_lock); 789 /* REV A cards use only 2 io ports; test 790 * presumes a floating bus reads as 0xff. */ 791 if ((inb(pcwd_private.io_addr + 2) == 0xFF) || 792 (inb(pcwd_private.io_addr + 3) == 0xFF)) 793 r = PCWD_REVISION_A; 794 spin_unlock(&pcwd_private.io_lock); 795 796 return r; 797} 798 799/* 800 * The ISA cards have a heartbeat bit in one of the registers, which 801 * register is card dependent. The heartbeat bit is monitored, and if 802 * found, is considered proof that a Berkshire card has been found. 803 * The initial rate is once per second at board start up, then twice 804 * per second for normal operation. 805 */ 806static int pcwd_isa_match(struct device *dev, unsigned int id) 807{ 808 int base_addr = pcwd_ioports[id]; 809 int port0, last_port0; /* Reg 0, in case it's REV A */ 810 int port1, last_port1; /* Register 1 for REV C cards */ 811 int i; 812 int retval; 813 814 if (debug >= DEBUG) 815 pr_debug("pcwd_isa_match id=%d\n", id); 816 817 if (!request_region(base_addr, 4, "PCWD")) { 818 pr_info("Port 0x%04x unavailable\n", base_addr); 819 return 0; 820 } 821 822 retval = 0; 823 824 port0 = inb_p(base_addr); /* For REV A boards */ 825 port1 = inb_p(base_addr + 1); /* For REV C boards */ 826 if (port0 != 0xff || port1 != 0xff) { 827 /* Not an 'ff' from a floating bus, so must be a card! */ 828 for (i = 0; i < 4; ++i) { 829 830 msleep(500); 831 832 last_port0 = port0; 833 last_port1 = port1; 834 835 port0 = inb_p(base_addr); 836 port1 = inb_p(base_addr + 1); 837 838 /* Has either hearbeat bit changed? */ 839 if ((port0 ^ last_port0) & WD_HRTBT || 840 (port1 ^ last_port1) & WD_REVC_HRBT) { 841 retval = 1; 842 break; 843 } 844 } 845 } 846 release_region(base_addr, 4); 847 848 return retval; 849} 850 851static int pcwd_isa_probe(struct device *dev, unsigned int id) 852{ 853 int ret; 854 855 if (debug >= DEBUG) 856 pr_debug("pcwd_isa_probe id=%d\n", id); 857 858 cards_found++; 859 if (cards_found == 1) 860 pr_info("v%s Ken Hollis (kenji@bitgate.com)\n", 861 WATCHDOG_VERSION); 862 863 if (cards_found > 1) { 864 pr_err("This driver only supports 1 device\n"); 865 return -ENODEV; 866 } 867 868 if (pcwd_ioports[id] == 0x0000) { 869 pr_err("No I/O-Address for card detected\n"); 870 return -ENODEV; 871 } 872 pcwd_private.io_addr = pcwd_ioports[id]; 873 874 spin_lock_init(&pcwd_private.io_lock); 875 876 /* Check card's revision */ 877 pcwd_private.revision = get_revision(); 878 879 if (!request_region(pcwd_private.io_addr, 880 (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) { 881 pr_err("I/O address 0x%04x already in use\n", 882 pcwd_private.io_addr); 883 ret = -EIO; 884 goto error_request_region; 885 } 886 887 /* Initial variables */ 888 pcwd_private.supports_temp = 0; 889 temp_panic = 0; 890 pcwd_private.boot_status = 0x0000; 891 892 /* get the boot_status */ 893 pcwd_get_status(&pcwd_private.boot_status); 894 895 /* clear the "card caused reboot" flag */ 896 pcwd_clear_status(); 897 898 timer_setup(&pcwd_private.timer, pcwd_timer_ping, 0); 899 900 /* Disable the board */ 901 pcwd_stop(); 902 903 /* Check whether or not the card supports the temperature device */ 904 pcwd_check_temperature_support(); 905 906 /* Show info about the card itself */ 907 pcwd_show_card_info(); 908 909 /* If heartbeat = 0 then we use the heartbeat from the dip-switches */ 910 if (heartbeat == 0) 911 heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)]; 912 913 /* Check that the heartbeat value is within it's range; 914 if not reset to the default */ 915 if (pcwd_set_heartbeat(heartbeat)) { 916 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT); 917 pr_info("heartbeat value must be 2 <= heartbeat <= 7200, using %d\n", 918 WATCHDOG_HEARTBEAT); 919 } 920 921 if (pcwd_private.supports_temp) { 922 ret = misc_register(&temp_miscdev); 923 if (ret) { 924 pr_err("cannot register miscdev on minor=%d (err=%d)\n", 925 TEMP_MINOR, ret); 926 goto error_misc_register_temp; 927 } 928 } 929 930 ret = misc_register(&pcwd_miscdev); 931 if (ret) { 932 pr_err("cannot register miscdev on minor=%d (err=%d)\n", 933 WATCHDOG_MINOR, ret); 934 goto error_misc_register_watchdog; 935 } 936 937 pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n", 938 heartbeat, nowayout); 939 940 return 0; 941 942error_misc_register_watchdog: 943 if (pcwd_private.supports_temp) 944 misc_deregister(&temp_miscdev); 945error_misc_register_temp: 946 release_region(pcwd_private.io_addr, 947 (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4); 948error_request_region: 949 pcwd_private.io_addr = 0x0000; 950 cards_found--; 951 return ret; 952} 953 954static void pcwd_isa_remove(struct device *dev, unsigned int id) 955{ 956 if (debug >= DEBUG) 957 pr_debug("pcwd_isa_remove id=%d\n", id); 958 959 /* Disable the board */ 960 if (!nowayout) 961 pcwd_stop(); 962 963 /* Deregister */ 964 misc_deregister(&pcwd_miscdev); 965 if (pcwd_private.supports_temp) 966 misc_deregister(&temp_miscdev); 967 release_region(pcwd_private.io_addr, 968 (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4); 969 pcwd_private.io_addr = 0x0000; 970 cards_found--; 971} 972 973static void pcwd_isa_shutdown(struct device *dev, unsigned int id) 974{ 975 if (debug >= DEBUG) 976 pr_debug("pcwd_isa_shutdown id=%d\n", id); 977 978 pcwd_stop(); 979} 980 981static struct isa_driver pcwd_isa_driver = { 982 .match = pcwd_isa_match, 983 .probe = pcwd_isa_probe, 984 .remove = pcwd_isa_remove, 985 .shutdown = pcwd_isa_shutdown, 986 .driver = { 987 .owner = THIS_MODULE, 988 .name = WATCHDOG_NAME, 989 }, 990}; 991 992module_isa_driver(pcwd_isa_driver, PCWD_ISA_NR_CARDS); 993 994MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, " 995 "Wim Van Sebroeck <wim@iguana.be>"); 996MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver"); 997MODULE_VERSION(WATCHDOG_VERSION); 998MODULE_LICENSE("GPL"); 999