drivers/watchdog/w83627hf_wdt.c

   1 /*
   2  *      w83627hf/thf WDT driver
   3  *
   4  *      (c) Copyright 2013 Guenter Roeck
   5  *              converted to watchdog infrastructure
   6  *
   7  *      (c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
   8  *              added support for W83627THF.
   9  *
  10  *      (c) Copyright 2003,2007 Pádraig Brady <P@draigBrady.com>
  11  *
  12  *      Based on advantechwdt.c which is based on wdt.c.
  13  *      Original copyright messages:
  14  *
  15  *      (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
  16  *
  17  *      (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
  18  *                                              All Rights Reserved.
  19  *
  20  *      This program is free software; you can redistribute it and/or
  21  *      modify it under the terms of the GNU General Public License
  22  *      as published by the Free Software Foundation; either version
  23  *      2 of the License, or (at your option) any later version.
  24  *
  25  *      Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
  26  *      warranty for any of this software. This material is provided
  27  *      "AS-IS" and at no charge.
  28  *
  29  *      (c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
  30  */
  31
  32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  33
  34 #include <linux/module.h>
  35 #include <linux/moduleparam.h>
  36 #include <linux/types.h>
  37 #include <linux/watchdog.h>
  38 #include <linux/ioport.h>
  39 #include <linux/notifier.h>
  40 #include <linux/reboot.h>
  41 #include <linux/init.h>
  42 #include <linux/io.h>
  43
  44 #define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT"
  45 #define WATCHDOG_TIMEOUT 60             /* 60 sec default timeout */
  46
  47 static int wdt_io;
  48 static int cr_wdt_timeout;      /* WDT timeout register */
  49 static int cr_wdt_control;      /* WDT control register */
  50
  51 enum chips { w83627hf, w83627s, w83697hf, w83697ug, w83637hf, w83627thf,
  52              w83687thf, w83627ehf, w83627dhg, w83627uhg, w83667hg, w83627dhg_p,
  53              w83667hg_b, nct6775, nct6776, nct6779 };
  54
  55 static int timeout;                     /* in seconds */
  56 module_param(timeout, int, 0);
  57 MODULE_PARM_DESC(timeout,
  58                 "Watchdog timeout in seconds. 1 <= timeout <= 255, default="
  59                                 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
  60
  61 static bool nowayout = WATCHDOG_NOWAYOUT;
  62 module_param(nowayout, bool, 0);
  63 MODULE_PARM_DESC(nowayout,
  64                 "Watchdog cannot be stopped once started (default="
  65                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  66
  67 static int early_disable;
  68 module_param(early_disable, int, 0);
  69 MODULE_PARM_DESC(early_disable, "Disable watchdog at boot time (default=0)");
  70
  71 /*
  72  *      Kernel methods.
  73  */
  74
  75 #define WDT_EFER (wdt_io+0)   /* Extended Function Enable Registers */
  76 #define WDT_EFIR (wdt_io+0)   /* Extended Function Index Register
  77                                                         (same as EFER) */
  78 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
  79
  80 #define W83627HF_LD_WDT         0x08
  81
  82 #define W83627HF_ID             0x52
  83 #define W83627S_ID              0x59
  84 #define W83697HF_ID             0x60
  85 #define W83697UG_ID             0x68
  86 #define W83637HF_ID             0x70
  87 #define W83627THF_ID            0x82
  88 #define W83687THF_ID            0x85
  89 #define W83627EHF_ID            0x88
  90 #define W83627DHG_ID            0xa0
  91 #define W83627UHG_ID            0xa2
  92 #define W83667HG_ID             0xa5
  93 #define W83627DHG_P_ID          0xb0
  94 #define W83667HG_B_ID           0xb3
  95 #define NCT6775_ID              0xb4
  96 #define NCT6776_ID              0xc3
  97 #define NCT6779_ID              0xc5
  98
  99 #define W83627HF_WDT_TIMEOUT    0xf6
 100 #define W83697HF_WDT_TIMEOUT    0xf4
 101
 102 #define W83627HF_WDT_CONTROL    0xf5
 103 #define W83697HF_WDT_CONTROL    0xf3
 104
 105 static void superio_outb(int reg, int val)
 106 {
 107         outb(reg, WDT_EFER);
 108         outb(val, WDT_EFDR);
 109 }
 110
 111 static inline int superio_inb(int reg)
 112 {
 113         outb(reg, WDT_EFER);
 114         return inb(WDT_EFDR);
 115 }
 116
 117 static int superio_enter(void)
 118 {
 119         if (!request_muxed_region(wdt_io, 2, WATCHDOG_NAME))
 120                 return -EBUSY;
 121
 122         outb_p(0x87, WDT_EFER); /* Enter extended function mode */
 123         outb_p(0x87, WDT_EFER); /* Again according to manual */
 124
 125         return 0;
 126 }
 127
 128 static void superio_select(int ld)
 129 {
 130         superio_outb(0x07, ld);
 131 }
 132
 133 static void superio_exit(void)
 134 {
 135         outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
 136         release_region(wdt_io, 2);
 137 }
 138
 139 static int w83627hf_init(struct watchdog_device *wdog, enum chips chip)
 140 {
 141         int ret;
 142         unsigned char t;
 143
 144         ret = superio_enter();
 145         if (ret)
 146                 return ret;
 147
 148         superio_select(W83627HF_LD_WDT);
 149
 150         /* set CR30 bit 0 to activate GPIO2 */
 151         t = superio_inb(0x30);
 152         if (!(t & 0x01))
 153                 superio_outb(0x30, t | 0x01);
 154
 155         switch (chip) {
 156         case w83627hf:
 157         case w83627s:
 158                 t = superio_inb(0x2B) & ~0x10;
 159                 superio_outb(0x2B, t); /* set GPIO24 to WDT0 */
 160                 break;
 161         case w83697hf:
 162                 /* Set pin 119 to WDTO# mode (= CR29, WDT0) */
 163                 t = superio_inb(0x29) & ~0x60;
 164                 t |= 0x20;
 165                 superio_outb(0x29, t);
 166                 break;
 167         case w83697ug:
 168                 /* Set pin 118 to WDTO# mode */
 169                 t = superio_inb(0x2b) & ~0x04;
 170                 superio_outb(0x2b, t);
 171                 break;
 172         case w83627thf:
 173                 t = (superio_inb(0x2B) & ~0x08) | 0x04;
 174                 superio_outb(0x2B, t); /* set GPIO3 to WDT0 */
 175                 break;
 176         case w83627dhg:
 177         case w83627dhg_p:
 178                 t = superio_inb(0x2D) & ~0x01; /* PIN77 -> WDT0# */
 179                 superio_outb(0x2D, t); /* set GPIO5 to WDT0 */
 180                 t = superio_inb(cr_wdt_control);
 181                 t |= 0x02;      /* enable the WDTO# output low pulse
 182                                  * to the KBRST# pin */
 183                 superio_outb(cr_wdt_control, t);
 184                 break;
 185         case w83637hf:
 186                 break;
 187         case w83687thf:
 188                 t = superio_inb(0x2C) & ~0x80; /* PIN47 -> WDT0# */
 189                 superio_outb(0x2C, t);
 190                 break;
 191         case w83627ehf:
 192         case w83627uhg:
 193         case w83667hg:
 194         case w83667hg_b:
 195         case nct6775:
 196         case nct6776:
 197         case nct6779:
 198                 /*
 199                  * These chips have a fixed WDTO# output pin (W83627UHG),
 200                  * or support more than one WDTO# output pin.
 201                  * Don't touch its configuration, and hope the BIOS
 202                  * does the right thing.
 203                  */
 204                 t = superio_inb(cr_wdt_control);
 205                 t |= 0x02;      /* enable the WDTO# output low pulse
 206                                  * to the KBRST# pin */
 207                 superio_outb(cr_wdt_control, t);
 208                 break;
 209         default:
 210                 break;
 211         }
 212
 213         t = superio_inb(cr_wdt_timeout);
 214         if (t != 0) {
 215                 if (early_disable) {
 216                         pr_warn("Stopping previously enabled watchdog until userland kicks in\n");
 217                         superio_outb(cr_wdt_timeout, 0);
 218                 } else {
 219                         pr_info("Watchdog already running. Resetting timeout to %d sec\n",
 220                                 wdog->timeout);
 221                         superio_outb(cr_wdt_timeout, wdog->timeout);
 222                 }
 223         }
 224
 225         /* set second mode & disable keyboard turning off watchdog */
 226         t = superio_inb(cr_wdt_control) & ~0x0C;
 227         superio_outb(cr_wdt_control, t);
 228
 229         /* reset trigger, disable keyboard & mouse turning off watchdog */
 230         t = superio_inb(0xF7) & ~0xD0;
 231         superio_outb(0xF7, t);
 232
 233         superio_exit();
 234
 235         return 0;
 236 }
 237
 238 static int wdt_set_time(unsigned int timeout)
 239 {
 240         int ret;
 241
 242         ret = superio_enter();
 243         if (ret)
 244                 return ret;
 245
 246         superio_select(W83627HF_LD_WDT);
 247         superio_outb(cr_wdt_timeout, timeout);
 248         superio_exit();
 249
 250         return 0;
 251 }
 252
 253 static int wdt_start(struct watchdog_device *wdog)
 254 {
 255         return wdt_set_time(wdog->timeout);
 256 }
 257
 258 static int wdt_stop(struct watchdog_device *wdog)
 259 {
 260         return wdt_set_time(0);
 261 }
 262
 263 static int wdt_set_timeout(struct watchdog_device *wdog, unsigned int timeout)
 264 {
 265         wdog->timeout = timeout;
 266
 267         return 0;
 268 }
 269
 270 static unsigned int wdt_get_time(struct watchdog_device *wdog)
 271 {
 272         unsigned int timeleft;
 273         int ret;
 274
 275         ret = superio_enter();
 276         if (ret)
 277                 return 0;
 278
 279         superio_select(W83627HF_LD_WDT);
 280         timeleft = superio_inb(cr_wdt_timeout);
 281         superio_exit();
 282
 283         return timeleft;
 284 }
 285
 286 /*
 287  *      Notifier for system down
 288  */
 289 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
 290         void *unused)
 291 {
 292         if (code == SYS_DOWN || code == SYS_HALT)
 293                 wdt_set_time(0);        /* Turn the WDT off */
 294
 295         return NOTIFY_DONE;
 296 }
 297
 298 /*
 299  *      Kernel Interfaces
 300  */
 301
 302 static struct watchdog_info wdt_info = {
 303         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
 304         .identity = "W83627HF Watchdog",
 305 };
 306
 307 static struct watchdog_ops wdt_ops = {
 308         .owner = THIS_MODULE,
 309         .start = wdt_start,
 310         .stop = wdt_stop,
 311         .set_timeout = wdt_set_timeout,
 312         .get_timeleft = wdt_get_time,
 313 };
 314
 315 static struct watchdog_device wdt_dev = {
 316         .info = &wdt_info,
 317         .ops = &wdt_ops,
 318         .timeout = WATCHDOG_TIMEOUT,
 319         .min_timeout = 1,
 320         .max_timeout = 255,
 321 };
 322
 323 /*
 324  *      The WDT needs to learn about soft shutdowns in order to
 325  *      turn the timebomb registers off.
 326  */
 327
 328 static struct notifier_block wdt_notifier = {
 329         .notifier_call = wdt_notify_sys,
 330 };
 331
 332 static int wdt_find(int addr)
 333 {
 334         u8 val;
 335         int ret;
 336
 337         cr_wdt_timeout = W83627HF_WDT_TIMEOUT;
 338         cr_wdt_control = W83627HF_WDT_CONTROL;
 339
 340         ret = superio_enter();
 341         if (ret)
 342                 return ret;
 343         superio_select(W83627HF_LD_WDT);
 344         val = superio_inb(0x20);
 345         switch (val) {
 346         case W83627HF_ID:
 347                 ret = w83627hf;
 348                 break;
 349         case W83627S_ID:
 350                 ret = w83627s;
 351                 break;
 352         case W83697HF_ID:
 353                 ret = w83697hf;
 354                 cr_wdt_timeout = W83697HF_WDT_TIMEOUT;
 355                 cr_wdt_control = W83697HF_WDT_CONTROL;
 356                 break;
 357         case W83697UG_ID:
 358                 ret = w83697ug;
 359                 cr_wdt_timeout = W83697HF_WDT_TIMEOUT;
 360                 cr_wdt_control = W83697HF_WDT_CONTROL;
 361                 break;
 362         case W83637HF_ID:
 363                 ret = w83637hf;
 364                 break;
 365         case W83627THF_ID:
 366                 ret = w83627thf;
 367                 break;
 368         case W83687THF_ID:
 369                 ret = w83687thf;
 370                 break;
 371         case W83627EHF_ID:
 372                 ret = w83627ehf;
 373                 break;
 374         case W83627DHG_ID:
 375                 ret = w83627dhg;
 376                 break;
 377         case W83627DHG_P_ID:
 378                 ret = w83627dhg_p;
 379                 break;
 380         case W83627UHG_ID:
 381                 ret = w83627uhg;
 382                 break;
 383         case W83667HG_ID:
 384                 ret = w83667hg;
 385                 break;
 386         case W83667HG_B_ID:
 387                 ret = w83667hg_b;
 388                 break;
 389         case NCT6775_ID:
 390                 ret = nct6775;
 391                 break;
 392         case NCT6776_ID:
 393                 ret = nct6776;
 394                 break;
 395         case NCT6779_ID:
 396                 ret = nct6779;
 397                 break;
 398         case 0xff:
 399                 ret = -ENODEV;
 400                 break;
 401         default:
 402                 ret = -ENODEV;
 403                 pr_err("Unsupported chip ID: 0x%02x\n", val);
 404                 break;
 405         }
 406         superio_exit();
 407         return ret;
 408 }
 409
 410 static int __init wdt_init(void)
 411 {
 412         int ret;
 413         int chip;
 414         const char * const chip_name[] = {
 415                 "W83627HF",
 416                 "W83627S",
 417                 "W83697HF",
 418                 "W83697UG",
 419                 "W83637HF",
 420                 "W83627THF",
 421                 "W83687THF",
 422                 "W83627EHF",
 423                 "W83627DHG",
 424                 "W83627UHG",
 425                 "W83667HG",
 426                 "W83667DHG-P",
 427                 "W83667HG-B",
 428                 "NCT6775",
 429                 "NCT6776",
 430                 "NCT6779",
 431         };
 432
 433         wdt_io = 0x2e;
 434         chip = wdt_find(0x2e);
 435         if (chip < 0) {
 436                 wdt_io = 0x4e;
 437                 chip = wdt_find(0x4e);
 438                 if (chip < 0)
 439                         return chip;
 440         }
 441
 442         pr_info("WDT driver for %s Super I/O chip initialising\n",
 443                 chip_name[chip]);
 444
 445         watchdog_init_timeout(&wdt_dev, timeout, NULL);
 446         watchdog_set_nowayout(&wdt_dev, nowayout);
 447
 448         ret = w83627hf_init(&wdt_dev, chip);
 449         if (ret) {
 450                 pr_err("failed to initialize watchdog (err=%d)\n", ret);
 451                 return ret;
 452         }
 453
 454         ret = register_reboot_notifier(&wdt_notifier);
 455         if (ret != 0) {
 456                 pr_err("cannot register reboot notifier (err=%d)\n", ret);
 457                 return ret;
 458         }
 459
 460         ret = watchdog_register_device(&wdt_dev);
 461         if (ret)
 462                 goto unreg_reboot;
 463
 464         pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
 465                 wdt_dev.timeout, nowayout);
 466
 467         return ret;
 468
 469 unreg_reboot:
 470         unregister_reboot_notifier(&wdt_notifier);
 471         return ret;
 472 }
 473
 474 static void __exit wdt_exit(void)
 475 {
 476         watchdog_unregister_device(&wdt_dev);
 477         unregister_reboot_notifier(&wdt_notifier);
 478 }
 479
 480 module_init(wdt_init);
 481 module_exit(wdt_exit);
 482
 483 MODULE_LICENSE("GPL");
 484 MODULE_AUTHOR("Pádraig  Brady <P@draigBrady.com>");
 485 MODULE_DESCRIPTION("w83627hf/thf WDT driver");