sys/platform/pc32/apm/apm.c

   1 /*
   2  * APM (Advanced Power Management) BIOS Device Driver
   3  *
   4  * Copyright (c) 1994 UKAI, Fumitoshi.
   5  * Copyright (c) 1994-1995 by HOSOKAWA, Tatsumi <hosokawa@jp.FreeBSD.org>
   6  * Copyright (c) 1996 Nate Williams <nate@FreeBSD.org>
   7  * Copyright (c) 1997 Poul-Henning Kamp <phk@FreeBSD.org>
   8  *
   9  * This software may be used, modified, copied, and distributed, in
  10  * both source and binary form provided that the above copyright and
  11  * these terms are retained. Under no circumstances is the author
  12  * responsible for the proper functioning of this software, nor does
  13  * the author assume any responsibility for damages incurred with its
  14  * use.
  15  *
  16  * Sep, 1994    Implemented on FreeBSD 1.1.5.1R (Toshiba AVS001WD)
  17  *
  18  * $FreeBSD: src/sys/i386/apm/apm.c,v 1.114.2.5 2002/11/02 04:41:50 iwasaki Exp $
  19  * $DragonFly: src/sys/platform/pc32/apm/apm.c,v 1.13 2005/12/24 20:34:04 swildner Exp $
  20  */
  21
  22 #include <sys/param.h>
  23 #include <sys/systm.h>
  24 #include <sys/eventhandler.h>
  25 #include <sys/conf.h>
  26 #include <sys/kernel.h>
  27 #include <sys/time.h>
  28 #include <sys/reboot.h>
  29 #include <sys/bus.h>
  30 #include <sys/select.h>
  31 #include <sys/poll.h>
  32 #include <sys/fcntl.h>
  33 #include <sys/uio.h>
  34 #include <sys/signalvar.h>
  35 #include <sys/sysctl.h>
  36 #include <machine/apm_bios.h>
  37 #include <machine/segments.h>
  38 #include <machine/clock.h>
  39 #include <vm/vm.h>
  40 #include <vm/vm_param.h>
  41 #include <vm/pmap.h>
  42 #include <sys/syslog.h>
  43 #include <sys/thread2.h>
  44
  45 #include <machine/pc/bios.h>
  46 #include <machine/vm86.h>
  47
  48 #include <i386/apm/apm.h>
  49
  50 /* Used by the apm_saver screen saver module */
  51 int apm_display (int newstate);
  52 struct apm_softc apm_softc;
  53
  54 static void apm_resume (void);
  55 static int apm_bioscall(void);
  56 static int apm_check_function_supported (u_int version, u_int func);
  57
  58 static u_long   apm_version;
  59
  60 int     apm_evindex;
  61
  62 #define SCFLAG_ONORMAL  0x0000001
  63 #define SCFLAG_OCTL     0x0000002
  64 #define SCFLAG_OPEN     (SCFLAG_ONORMAL|SCFLAG_OCTL)
  65
  66 #define APMDEV(dev)     (minor(dev)&0x0f)
  67 #define APMDEV_NORMAL   0
  68 #define APMDEV_CTL      8
  69
  70 static struct apmhook   *hook[NAPM_HOOK];               /* XXX */
  71
  72 #define is_enabled(foo) ((foo) ? "enabled" : "disabled")
  73
  74 /* Map version number to integer (keeps ordering of version numbers) */
  75 #define INTVERSION(major, minor)        ((major)*100 + (minor))
  76
  77 static struct callout apm_timeout_ch;
  78
  79 static timeout_t apm_timeout;
  80 static d_open_t apmopen;
  81 static d_close_t apmclose;
  82 static d_write_t apmwrite;
  83 static d_ioctl_t apmioctl;
  84 static d_poll_t apmpoll;
  85
  86 #define CDEV_MAJOR 39
  87 static struct cdevsw apm_cdevsw = {
  88         /* name */      "apm",
  89         /* maj */       CDEV_MAJOR,
  90         /* flags */     0,
  91         /* port */      NULL,
  92         /* clone */     NULL,
  93
  94         /* open */      apmopen,
  95         /* close */     apmclose,
  96         /* read */      noread,
  97         /* write */     apmwrite,
  98         /* ioctl */     apmioctl,
  99         /* poll */      apmpoll,
 100         /* mmap */      nommap,
 101         /* strategy */  nostrategy,
 102         /* dump */      nodump,
 103         /* psize */     nopsize
 104 };
 105
 106 static int apm_suspend_delay = 1;
 107 static int apm_standby_delay = 1;
 108 static int apm_debug = 0;
 109
 110 #define APM_DPRINT(args...) do  {                                       \
 111         if (apm_debug) {                                                \
 112                 printf(args);                                           \
 113         }                                                               \
 114 } while (0)
 115
 116 SYSCTL_INT(_machdep, OID_AUTO, apm_suspend_delay, CTLFLAG_RW, &apm_suspend_delay, 1, "");
 117 SYSCTL_INT(_machdep, OID_AUTO, apm_standby_delay, CTLFLAG_RW, &apm_standby_delay, 1, "");
 118 SYSCTL_INT(_debug, OID_AUTO, apm_debug, CTLFLAG_RW, &apm_debug, 0, "");
 119
 120 /*
 121  * return  0 if the function successfull,
 122  * return  1 if the function unsuccessfull,
 123  * return -1 if the function unsupported.
 124  */
 125 static int
 126 apm_bioscall(void)
 127 {
 128         struct apm_softc *sc = &apm_softc;
 129         int errno = 0;
 130         u_int apm_func = sc->bios.r.eax & 0xff;
 131
 132         if (!apm_check_function_supported(sc->intversion, apm_func)) {
 133                 APM_DPRINT("apm_bioscall: function 0x%x is not supported in v%d.%d\n",
 134                     apm_func, sc->majorversion, sc->minorversion);
 135                 return (-1);
 136         }
 137
 138         sc->bios_busy = 1;
 139         if (sc->connectmode == APM_PROT32CONNECT) {
 140                 set_bios_selectors(&sc->bios.seg,
 141                                    BIOSCODE_FLAG | BIOSDATA_FLAG);
 142                 errno = bios32(&sc->bios.r,
 143                                sc->bios.entry, GSEL(GBIOSCODE32_SEL, SEL_KPL));
 144         } else {
 145                 errno = bios16(&sc->bios, NULL);
 146         }
 147         sc->bios_busy = 0;
 148         return (errno);
 149 }
 150
 151 /* check whether APM function is supported (1)  or not (0). */
 152 static int
 153 apm_check_function_supported(u_int version, u_int func)
 154 {
 155         /* except driver version */
 156         if (func == APM_DRVVERSION) {
 157                 return (1);
 158         }
 159
 160         switch (version) {
 161         case INTVERSION(1, 0):
 162                 if (func > APM_GETPMEVENT) {
 163                         return (0); /* not supported */
 164                 }
 165                 break;
 166         case INTVERSION(1, 1):
 167                 if (func > APM_ENGAGEDISENGAGEPM &&
 168                     func < APM_OEMFUNC) {
 169                         return (0); /* not supported */
 170                 }
 171                 break;
 172         case INTVERSION(1, 2):
 173                 break;
 174         }
 175
 176         return (1); /* supported */
 177 }
 178
 179 /* enable/disable power management */
 180 static int
 181 apm_enable_disable_pm(int enable)
 182 {
 183         struct apm_softc *sc = &apm_softc;
 184
 185         sc->bios.r.eax = (APM_BIOS << 8) | APM_ENABLEDISABLEPM;
 186
 187         if (sc->intversion >= INTVERSION(1, 1))
 188                 sc->bios.r.ebx  = PMDV_ALLDEV;
 189         else
 190                 sc->bios.r.ebx  = 0xffff;       /* APM version 1.0 only */
 191         sc->bios.r.ecx  = enable;
 192         sc->bios.r.edx = 0;
 193         return (apm_bioscall());
 194 }
 195
 196 /* register driver version (APM 1.1 or later) */
 197 static int
 198 apm_driver_version(int version)
 199 {
 200         struct apm_softc *sc = &apm_softc;
 201
 202         sc->bios.r.eax = (APM_BIOS << 8) | APM_DRVVERSION;
 203         sc->bios.r.ebx  = 0x0;
 204         sc->bios.r.ecx  = version;
 205         sc->bios.r.edx = 0;
 206
 207         if (apm_bioscall() == 0 && sc->bios.r.eax == version)
 208                 return (0);
 209
 210         /* Some old BIOSes don't return the connection version in %ax. */
 211         if (sc->bios.r.eax == ((APM_BIOS << 8) | APM_DRVVERSION))
 212                 return (0);
 213
 214         return (1);
 215 }
 216
 217 /* engage/disengage power management (APM 1.1 or later) */
 218 static int
 219 apm_engage_disengage_pm(int engage)
 220 {
 221         struct apm_softc *sc = &apm_softc;
 222
 223         sc->bios.r.eax = (APM_BIOS << 8) | APM_ENGAGEDISENGAGEPM;
 224         sc->bios.r.ebx = PMDV_ALLDEV;
 225         sc->bios.r.ecx = engage;
 226         sc->bios.r.edx = 0;
 227         return (apm_bioscall());
 228 }
 229
 230 /* get PM event */
 231 static u_int
 232 apm_getevent(void)
 233 {
 234         struct apm_softc *sc = &apm_softc;
 235
 236         sc->bios.r.eax = (APM_BIOS << 8) | APM_GETPMEVENT;
 237
 238         sc->bios.r.ebx = 0;
 239         sc->bios.r.ecx = 0;
 240         sc->bios.r.edx = 0;
 241         if (apm_bioscall())
 242                 return (PMEV_NOEVENT);
 243         return (sc->bios.r.ebx & 0xffff);
 244 }
 245
 246 /* suspend entire system */
 247 static int
 248 apm_suspend_system(int state)
 249 {
 250         struct apm_softc *sc = &apm_softc;
 251
 252         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 253         sc->bios.r.ebx = PMDV_ALLDEV;
 254         sc->bios.r.ecx = state;
 255         sc->bios.r.edx = 0;
 256
 257         if (apm_bioscall()) {
 258                 printf("Entire system suspend failure: errcode = %d\n",
 259                        0xff & (sc->bios.r.eax >> 8));
 260                 return 1;
 261         }
 262         return 0;
 263 }
 264
 265 /* Display control */
 266 /*
 267  * Experimental implementation: My laptop machine can't handle this function
 268  * If your laptop can control the display via APM, please inform me.
 269  *                            HOSOKAWA, Tatsumi <hosokawa@jp.FreeBSD.org>
 270  */
 271 int
 272 apm_display(int newstate)
 273 {
 274         struct apm_softc *sc = &apm_softc;
 275
 276         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 277         sc->bios.r.ebx = PMDV_DISP0;
 278         sc->bios.r.ecx = newstate ? PMST_APMENABLED:PMST_SUSPEND;
 279         sc->bios.r.edx = 0;
 280         if (apm_bioscall() == 0) {
 281                 return 0;
 282         }
 283
 284         /* If failed, then try to blank all display devices instead. */
 285         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 286         sc->bios.r.ebx = PMDV_DISPALL;  /* all display devices */
 287         sc->bios.r.ecx = newstate ? PMST_APMENABLED:PMST_SUSPEND;
 288         sc->bios.r.edx = 0;
 289         if (apm_bioscall() == 0) {
 290                 return 0;
 291         }
 292         printf("Display off failure: errcode = %d\n",
 293                0xff & (sc->bios.r.eax >> 8));
 294         return 1;
 295 }
 296
 297 /*
 298  * Turn off the entire system.
 299  */
 300 static void
 301 apm_power_off(void *junk, int howto)
 302 {
 303         struct apm_softc *sc = &apm_softc;
 304
 305         /* Not halting powering off, or not active */
 306         if (!(howto & RB_POWEROFF) || !apm_softc.active)
 307                 return;
 308         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 309         sc->bios.r.ebx = PMDV_ALLDEV;
 310         sc->bios.r.ecx = PMST_OFF;
 311         sc->bios.r.edx = 0;
 312         apm_bioscall();
 313 }
 314
 315 /* APM Battery low handler */
 316 static void
 317 apm_battery_low(void)
 318 {
 319         printf("\007\007 * * * BATTERY IS LOW * * * \007\007");
 320 }
 321
 322 /* APM hook manager */
 323 static struct apmhook *
 324 apm_add_hook(struct apmhook **list, struct apmhook *ah)
 325 {
 326         struct apmhook *p, *prev;
 327
 328         APM_DPRINT("Add hook \"%s\"\n", ah->ah_name);
 329
 330         crit_enter();
 331         if (ah == NULL)
 332                 panic("illegal apm_hook!");
 333         prev = NULL;
 334         for (p = *list; p != NULL; prev = p, p = p->ah_next)
 335                 if (p->ah_order > ah->ah_order)
 336                         break;
 337
 338         if (prev == NULL) {
 339                 ah->ah_next = *list;
 340                 *list = ah;
 341         } else {
 342                 ah->ah_next = prev->ah_next;
 343                 prev->ah_next = ah;
 344         }
 345         crit_exit();
 346         return ah;
 347 }
 348
 349 static void
 350 apm_del_hook(struct apmhook **list, struct apmhook *ah)
 351 {
 352         struct apmhook *p, *prev;
 353
 354         crit_enter();
 355         prev = NULL;
 356         for (p = *list; p != NULL; prev = p, p = p->ah_next)
 357                 if (p == ah)
 358                         goto deleteit;
 359         panic("Tried to delete unregistered apm_hook.");
 360         goto nosuchnode;
 361 deleteit:
 362         if (prev != NULL)
 363                 prev->ah_next = p->ah_next;
 364         else
 365                 *list = p->ah_next;
 366 nosuchnode:
 367         crit_exit();
 368 }
 369
 370
 371 /* APM driver calls some functions automatically */
 372 static void
 373 apm_execute_hook(struct apmhook *list)
 374 {
 375         struct apmhook *p;
 376
 377         for (p = list; p != NULL; p = p->ah_next) {
 378                 APM_DPRINT("Execute APM hook \"%s.\"\n", p->ah_name);
 379                 if ((*(p->ah_fun))(p->ah_arg))
 380                         printf("Warning: APM hook \"%s\" failed", p->ah_name);
 381         }
 382 }
 383
 384
 385 /* establish an apm hook */
 386 struct apmhook *
 387 apm_hook_establish(int apmh, struct apmhook *ah)
 388 {
 389         if (apmh < 0 || apmh >= NAPM_HOOK)
 390                 return NULL;
 391
 392         return apm_add_hook(&hook[apmh], ah);
 393 }
 394
 395 /* disestablish an apm hook */
 396 void
 397 apm_hook_disestablish(int apmh, struct apmhook *ah)
 398 {
 399         if (apmh < 0 || apmh >= NAPM_HOOK)
 400                 return;
 401
 402         apm_del_hook(&hook[apmh], ah);
 403 }
 404
 405
 406 static struct timeval suspend_time;
 407 static struct timeval diff_time;
 408
 409 static int
 410 apm_default_resume(void *arg)
 411 {
 412         u_int second, minute, hour;
 413         struct timeval resume_time, tmp_time;
 414
 415         /* modified for adjkerntz */
 416         crit_enter();
 417         timer_restore();                /* restore the all timers */
 418         inittodr(0);                    /* adjust time to RTC */
 419         microtime(&resume_time);
 420         getmicrotime(&tmp_time);
 421         timevaladd(&tmp_time, &diff_time);
 422
 423 #ifdef FIXME
 424         /* XXX THIS DOESN'T WORK!!! */
 425         time = tmp_time;
 426 #endif
 427
 428 #ifdef APM_FIXUP_CALLTODO
 429         /* Calculate the delta time suspended */
 430         timevalsub(&resume_time, &suspend_time);
 431         /* Fixup the calltodo list with the delta time. */
 432         adjust_timeout_calltodo(&resume_time);
 433 #endif /* APM_FIXUP_CALLTODOK */
 434         crit_exit();
 435 #ifndef APM_FIXUP_CALLTODO
 436         second = resume_time.tv_sec - suspend_time.tv_sec;
 437 #else /* APM_FIXUP_CALLTODO */
 438         /*
 439          * We've already calculated resume_time to be the delta between
 440          * the suspend and the resume.
 441          */
 442         second = resume_time.tv_sec;
 443 #endif /* APM_FIXUP_CALLTODO */
 444         hour = second / 3600;
 445         second %= 3600;
 446         minute = second / 60;
 447         second %= 60;
 448         log(LOG_NOTICE, "resumed from suspended mode (slept %02d:%02d:%02d)\n",
 449                 hour, minute, second);
 450         return 0;
 451 }
 452
 453 static int
 454 apm_default_suspend(void *arg)
 455 {
 456         crit_enter();
 457         microtime(&diff_time);
 458         inittodr(0);
 459         microtime(&suspend_time);
 460         timevalsub(&diff_time, &suspend_time);
 461         crit_exit();
 462         return 0;
 463 }
 464
 465 static int apm_record_event (struct apm_softc *, u_int);
 466 static void apm_processevent(void);
 467
 468 static u_int apm_op_inprog = 0;
 469
 470 static void
 471 apm_do_suspend(void)
 472 {
 473         struct apm_softc *sc = &apm_softc;
 474         int error;
 475
 476         if (!sc)
 477                 return;
 478
 479         apm_op_inprog = 0;
 480         sc->suspends = sc->suspend_countdown = 0;
 481
 482         if (sc->initialized) {
 483                 error = DEVICE_SUSPEND(root_bus);
 484                 if (error) {
 485                         DEVICE_RESUME(root_bus);
 486                 } else {
 487                         apm_execute_hook(hook[APM_HOOK_SUSPEND]);
 488                         if (apm_suspend_system(PMST_SUSPEND) == 0) {
 489                                 apm_processevent();
 490                         } else {
 491                                 /* Failure, 'resume' the system again */
 492                                 apm_execute_hook(hook[APM_HOOK_RESUME]);
 493                                 DEVICE_RESUME(root_bus);
 494                         }
 495                 }
 496         }
 497 }
 498
 499 static void
 500 apm_do_standby(void)
 501 {
 502         struct apm_softc *sc = &apm_softc;
 503
 504         if (!sc)
 505                 return;
 506
 507         apm_op_inprog = 0;
 508         sc->standbys = sc->standby_countdown = 0;
 509
 510         if (sc->initialized) {
 511                 /*
 512                  * As far as standby, we don't need to execute
 513                  * all of suspend hooks.
 514                  */
 515                 apm_default_suspend(&apm_softc);
 516                 if (apm_suspend_system(PMST_STANDBY) == 0)
 517                         apm_processevent();
 518         }
 519 }
 520
 521 static void
 522 apm_lastreq_notify(void)
 523 {
 524         struct apm_softc *sc = &apm_softc;
 525
 526         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 527         sc->bios.r.ebx = PMDV_ALLDEV;
 528         sc->bios.r.ecx = PMST_LASTREQNOTIFY;
 529         sc->bios.r.edx = 0;
 530         apm_bioscall();
 531 }
 532
 533 static int
 534 apm_lastreq_rejected(void)
 535 {
 536         struct apm_softc *sc = &apm_softc;
 537
 538         if (apm_op_inprog == 0) {
 539                 return 1;       /* no operation in progress */
 540         }
 541
 542         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 543         sc->bios.r.ebx = PMDV_ALLDEV;
 544         sc->bios.r.ecx = PMST_LASTREQREJECT;
 545         sc->bios.r.edx = 0;
 546
 547         if (apm_bioscall()) {
 548                 APM_DPRINT("apm_lastreq_rejected: failed\n");
 549                 return 1;
 550         }
 551         apm_op_inprog = 0;
 552         return 0;
 553 }
 554
 555 /*
 556  * Public interface to the suspend/resume:
 557  *
 558  * Execute suspend and resume hook before and after sleep, respectively.
 559  *
 560  */
 561
 562 void
 563 apm_suspend(int state)
 564 {
 565         struct apm_softc *sc = &apm_softc;
 566
 567         if (!sc->initialized)
 568                 return;
 569
 570         switch (state) {
 571         case PMST_SUSPEND:
 572                 if (sc->suspends)
 573                         return;
 574                 sc->suspends++;
 575                 sc->suspend_countdown = apm_suspend_delay;
 576                 break;
 577         case PMST_STANDBY:
 578                 if (sc->standbys)
 579                         return;
 580                 sc->standbys++;
 581                 sc->standby_countdown = apm_standby_delay;
 582                 break;
 583         default:
 584                 printf("apm_suspend: Unknown Suspend state 0x%x\n", state);
 585                 return;
 586         }
 587
 588         apm_op_inprog++;
 589         apm_lastreq_notify();
 590 }
 591
 592 void
 593 apm_resume(void)
 594 {
 595         struct apm_softc *sc = &apm_softc;
 596
 597         if (!sc)
 598                 return;
 599
 600         if (sc->initialized) {
 601                 apm_execute_hook(hook[APM_HOOK_RESUME]);
 602                 DEVICE_RESUME(root_bus);
 603         }
 604 }
 605
 606
 607 /* get power status per battery */
 608 static int
 609 apm_get_pwstatus(apm_pwstatus_t app)
 610 {
 611         struct apm_softc *sc = &apm_softc;
 612
 613         if (app->ap_device != PMDV_ALLDEV &&
 614             (app->ap_device < PMDV_BATT0 || app->ap_device > PMDV_BATT_ALL))
 615                 return 1;
 616
 617         sc->bios.r.eax = (APM_BIOS << 8) | APM_GETPWSTATUS;
 618         sc->bios.r.ebx = app->ap_device;
 619         sc->bios.r.ecx = 0;
 620         sc->bios.r.edx = 0xffff;        /* default to unknown battery time */
 621
 622         if (apm_bioscall())
 623                 return 1;
 624
 625         app->ap_acline    = (sc->bios.r.ebx >> 8) & 0xff;
 626         app->ap_batt_stat = sc->bios.r.ebx & 0xff;
 627         app->ap_batt_flag = (sc->bios.r.ecx >> 8) & 0xff;
 628         app->ap_batt_life = sc->bios.r.ecx & 0xff;
 629         sc->bios.r.edx &= 0xffff;
 630         if (sc->bios.r.edx == 0xffff)   /* Time is unknown */
 631                 app->ap_batt_time = -1;
 632         else if (sc->bios.r.edx & 0x8000)       /* Time is in minutes */
 633                 app->ap_batt_time = (sc->bios.r.edx & 0x7fff) * 60;
 634         else                            /* Time is in seconds */
 635                 app->ap_batt_time = sc->bios.r.edx;
 636
 637         return 0;
 638 }
 639
 640
 641 /* get APM information */
 642 static int
 643 apm_get_info(apm_info_t aip)
 644 {
 645         struct apm_softc *sc = &apm_softc;
 646         struct apm_pwstatus aps;
 647
 648         bzero(&aps, sizeof(aps));
 649         aps.ap_device = PMDV_ALLDEV;
 650         if (apm_get_pwstatus(&aps))
 651                 return 1;
 652
 653         aip->ai_infoversion = 1;
 654         aip->ai_acline      = aps.ap_acline;
 655         aip->ai_batt_stat   = aps.ap_batt_stat;
 656         aip->ai_batt_life   = aps.ap_batt_life;
 657         aip->ai_batt_time   = aps.ap_batt_time;
 658         aip->ai_major       = (u_int)sc->majorversion;
 659         aip->ai_minor       = (u_int)sc->minorversion;
 660         aip->ai_status      = (u_int)sc->active;
 661
 662         sc->bios.r.eax = (APM_BIOS << 8) | APM_GETCAPABILITIES;
 663         sc->bios.r.ebx = 0;
 664         sc->bios.r.ecx = 0;
 665         sc->bios.r.edx = 0;
 666         if (apm_bioscall()) {
 667                 aip->ai_batteries = -1; /* Unknown */
 668                 aip->ai_capabilities = 0xff00; /* Unknown, with no bits set */
 669         } else {
 670                 aip->ai_batteries = sc->bios.r.ebx & 0xff;
 671                 aip->ai_capabilities = sc->bios.r.ecx & 0xf;
 672         }
 673
 674         bzero(aip->ai_spare, sizeof aip->ai_spare);
 675
 676         return 0;
 677 }
 678
 679
 680 /* inform APM BIOS that CPU is idle */
 681 void
 682 apm_cpu_idle(void)
 683 {
 684         struct apm_softc *sc = &apm_softc;
 685
 686         if (sc->active) {
 687
 688                 sc->bios.r.eax = (APM_BIOS <<8) | APM_CPUIDLE;
 689                 sc->bios.r.edx = sc->bios.r.ecx = sc->bios.r.ebx = 0;
 690                 apm_bioscall();
 691         }
 692         /*
 693          * Some APM implementation halts CPU in BIOS, whenever
 694          * "CPU-idle" function are invoked, but swtch() of
 695          * FreeBSD halts CPU, therefore, CPU is halted twice
 696          * in the sched loop. It makes the interrupt latency
 697          * terribly long and be able to cause a serious problem
 698          * in interrupt processing. We prevent it by removing
 699          * "hlt" operation from swtch() and managed it under
 700          * APM driver.
 701          */
 702         if (!sc->active || sc->always_halt_cpu)
 703                 __asm("hlt");   /* wait for interrupt */
 704 }
 705
 706 /* inform APM BIOS that CPU is busy */
 707 void
 708 apm_cpu_busy(void)
 709 {
 710         struct apm_softc *sc = &apm_softc;
 711
 712         /*
 713          * The APM specification says this is only necessary if your BIOS
 714          * slows down the processor in the idle task, otherwise it's not
 715          * necessary.
 716          */
 717         if (sc->slow_idle_cpu && sc->active) {
 718
 719                 sc->bios.r.eax = (APM_BIOS <<8) | APM_CPUBUSY;
 720                 sc->bios.r.edx = sc->bios.r.ecx = sc->bios.r.ebx = 0;
 721                 apm_bioscall();
 722         }
 723 }
 724
 725
 726 /*
 727  * APM timeout routine:
 728  *
 729  * This routine is automatically called by timer once per second.
 730  */
 731
 732 static void
 733 apm_timeout(void *dummy)
 734 {
 735         struct apm_softc *sc = &apm_softc;
 736
 737         if (apm_op_inprog)
 738                 apm_lastreq_notify();
 739
 740         if (sc->standbys && sc->standby_countdown-- <= 0)
 741                 apm_do_standby();
 742
 743         if (sc->suspends && sc->suspend_countdown-- <= 0)
 744                 apm_do_suspend();
 745
 746         if (!sc->bios_busy)
 747                 apm_processevent();
 748
 749         if (sc->active == 1) {
 750                 /* Run slightly more oftan than 1 Hz */
 751                 callout_reset(&apm_timeout_ch, hz - 1, apm_timeout, NULL);
 752         }
 753 }
 754
 755 /* enable APM BIOS */
 756 static void
 757 apm_event_enable(void)
 758 {
 759         struct apm_softc *sc = &apm_softc;
 760
 761         APM_DPRINT("called apm_event_enable()\n");
 762         if (sc->initialized) {
 763                 sc->active = 1;
 764                 callout_init(&apm_timeout_ch);
 765                 apm_timeout(sc);
 766         }
 767 }
 768
 769 /* disable APM BIOS */
 770 static void
 771 apm_event_disable(void)
 772 {
 773         struct apm_softc *sc = &apm_softc;
 774
 775         APM_DPRINT("called apm_event_disable()\n");
 776         if (sc->initialized) {
 777                 callout_stop(&apm_timeout_ch);
 778                 sc->active = 0;
 779         }
 780 }
 781
 782 /* halt CPU in scheduling loop */
 783 static void
 784 apm_halt_cpu(void)
 785 {
 786         struct apm_softc *sc = &apm_softc;
 787
 788         if (sc->initialized)
 789                 sc->always_halt_cpu = 1;
 790 }
 791
 792 /* don't halt CPU in scheduling loop */
 793 static void
 794 apm_not_halt_cpu(void)
 795 {
 796         struct apm_softc *sc = &apm_softc;
 797
 798         if (sc->initialized)
 799                 sc->always_halt_cpu = 0;
 800 }
 801
 802 /* device driver definitions */
 803
 804 /*
 805  * probe for APM BIOS
 806  */
 807 static int
 808 apm_probe(device_t dev)
 809 {
 810 #define APM_KERNBASE    KERNBASE
 811         struct vm86frame        vmf;
 812         struct apm_softc        *sc = &apm_softc;
 813         int                     disabled, flags;
 814
 815         if (resource_int_value("apm", 0, "disabled", &disabled) == 0
 816             && disabled != 0)
 817                 return ENXIO;
 818
 819         device_set_desc(dev, "APM BIOS");
 820
 821         if ( device_get_unit(dev) > 0 ) {
 822                 printf("apm: Only one APM driver supported.\n");
 823                 return ENXIO;
 824         }
 825
 826         if (resource_int_value("apm", 0, "flags", &flags) != 0)
 827                 flags = 0;
 828
 829         bzero(&vmf, sizeof(struct vm86frame));          /* safety */
 830         bzero(&apm_softc, sizeof(apm_softc));
 831         vmf.vmf_ah = APM_BIOS;
 832         vmf.vmf_al = APM_INSTCHECK;
 833         vmf.vmf_bx = 0;
 834         if (vm86_intcall(APM_INT, &vmf))
 835                 return ENXIO;                   /* APM not found */
 836         if (vmf.vmf_bx != 0x504d) {
 837                 printf("apm: incorrect signature (0x%x)\n", vmf.vmf_bx);
 838                 return ENXIO;
 839         }
 840         if ((vmf.vmf_cx & (APM_32BIT_SUPPORT | APM_16BIT_SUPPORT)) == 0) {
 841                 printf("apm: protected mode connections are not supported\n");
 842                 return ENXIO;
 843         }
 844
 845         apm_version = vmf.vmf_ax;
 846         sc->slow_idle_cpu = ((vmf.vmf_cx & APM_CPUIDLE_SLOW) != 0);
 847         sc->disabled = ((vmf.vmf_cx & APM_DISABLED) != 0);
 848         sc->disengaged = ((vmf.vmf_cx & APM_DISENGAGED) != 0);
 849
 850         vmf.vmf_ah = APM_BIOS;
 851         vmf.vmf_al = APM_DISCONNECT;
 852         vmf.vmf_bx = 0;
 853         vm86_intcall(APM_INT, &vmf);            /* disconnect, just in case */
 854
 855         if ((vmf.vmf_cx & APM_32BIT_SUPPORT) != 0) {
 856                 vmf.vmf_ah = APM_BIOS;
 857                 vmf.vmf_al = APM_PROT32CONNECT;
 858                 vmf.vmf_bx = 0;
 859                 if (vm86_intcall(APM_INT, &vmf)) {
 860                         printf("apm: 32-bit connection error.\n");
 861                         return (ENXIO);
 862                 }
 863                 sc->bios.seg.code32.base = (vmf.vmf_ax << 4) + APM_KERNBASE;
 864                 sc->bios.seg.code32.limit = 0xffff;
 865                 sc->bios.seg.code16.base = (vmf.vmf_cx << 4) + APM_KERNBASE;
 866                 sc->bios.seg.code16.limit = 0xffff;
 867                 sc->bios.seg.data.base = (vmf.vmf_dx << 4) + APM_KERNBASE;
 868                 sc->bios.seg.data.limit = 0xffff;
 869                 sc->bios.entry = vmf.vmf_ebx;
 870                 sc->connectmode = APM_PROT32CONNECT;
 871         } else {
 872                 /* use 16-bit connection */
 873                 vmf.vmf_ah = APM_BIOS;
 874                 vmf.vmf_al = APM_PROT16CONNECT;
 875                 vmf.vmf_bx = 0;
 876                 if (vm86_intcall(APM_INT, &vmf)) {
 877                         printf("apm: 16-bit connection error.\n");
 878                         return (ENXIO);
 879                 }
 880                 sc->bios.seg.code16.base = (vmf.vmf_ax << 4) + APM_KERNBASE;
 881                 sc->bios.seg.code16.limit = 0xffff;
 882                 sc->bios.seg.data.base = (vmf.vmf_cx << 4) + APM_KERNBASE;
 883                 sc->bios.seg.data.limit = 0xffff;
 884                 sc->bios.entry = vmf.vmf_bx;
 885                 sc->connectmode = APM_PROT16CONNECT;
 886         }
 887         return(0);
 888 }
 889
 890
 891 /*
 892  * return 0 if the user will notice and handle the event,
 893  * return 1 if the kernel driver should do so.
 894  */
 895 static int
 896 apm_record_event(struct apm_softc *sc, u_int event_type)
 897 {
 898         struct apm_event_info *evp;
 899
 900         if ((sc->sc_flags & SCFLAG_OPEN) == 0)
 901                 return 1;               /* no user waiting */
 902         if (sc->event_count == APM_NEVENTS)
 903                 return 1;                       /* overflow */
 904         if (sc->event_filter[event_type] == 0)
 905                 return 1;               /* not registered */
 906         evp = &sc->event_list[sc->event_ptr];
 907         sc->event_count++;
 908         sc->event_ptr++;
 909         sc->event_ptr %= APM_NEVENTS;
 910         evp->type = event_type;
 911         evp->index = ++apm_evindex;
 912         selwakeup(&sc->sc_rsel);
 913         return (sc->sc_flags & SCFLAG_OCTL) ? 0 : 1; /* user may handle */
 914 }
 915
 916 /* Process APM event */
 917 static void
 918 apm_processevent(void)
 919 {
 920         int apm_event;
 921         struct apm_softc *sc = &apm_softc;
 922
 923 #define OPMEV_DEBUGMESSAGE(symbol) case symbol:                         \
 924         APM_DPRINT("Received APM Event: " #symbol "\n");
 925
 926         do {
 927                 apm_event = apm_getevent();
 928                 switch (apm_event) {
 929                     OPMEV_DEBUGMESSAGE(PMEV_STANDBYREQ);
 930                         if (apm_op_inprog == 0) {
 931                             apm_op_inprog++;
 932                             if (apm_record_event(sc, apm_event)) {
 933                                 apm_suspend(PMST_STANDBY);
 934                             }
 935                         }
 936                         break;
 937                     OPMEV_DEBUGMESSAGE(PMEV_USERSTANDBYREQ);
 938                         if (apm_op_inprog == 0) {
 939                             apm_op_inprog++;
 940                             if (apm_record_event(sc, apm_event)) {
 941                                 apm_suspend(PMST_STANDBY);
 942                             }
 943                         }
 944                         break;
 945                     OPMEV_DEBUGMESSAGE(PMEV_SUSPENDREQ);
 946                         apm_lastreq_notify();
 947                         if (apm_op_inprog == 0) {
 948                             apm_op_inprog++;
 949                             if (apm_record_event(sc, apm_event)) {
 950                                 apm_do_suspend();
 951                             }
 952                         }
 953                         return; /* XXX skip the rest */
 954                     OPMEV_DEBUGMESSAGE(PMEV_USERSUSPENDREQ);
 955                         apm_lastreq_notify();
 956                         if (apm_op_inprog == 0) {
 957                             apm_op_inprog++;
 958                             if (apm_record_event(sc, apm_event)) {
 959                                 apm_do_suspend();
 960                             }
 961                         }
 962                         return; /* XXX skip the rest */
 963                     OPMEV_DEBUGMESSAGE(PMEV_CRITSUSPEND);
 964                         apm_do_suspend();
 965                         break;
 966                     OPMEV_DEBUGMESSAGE(PMEV_NORMRESUME);
 967                         apm_record_event(sc, apm_event);
 968                         apm_resume();
 969                         break;
 970                     OPMEV_DEBUGMESSAGE(PMEV_CRITRESUME);
 971                         apm_record_event(sc, apm_event);
 972                         apm_resume();
 973                         break;
 974                     OPMEV_DEBUGMESSAGE(PMEV_STANDBYRESUME);
 975                         apm_record_event(sc, apm_event);
 976                         apm_resume();
 977                         break;
 978                     OPMEV_DEBUGMESSAGE(PMEV_BATTERYLOW);
 979                         if (apm_record_event(sc, apm_event)) {
 980                             apm_battery_low();
 981                             apm_suspend(PMST_SUSPEND);
 982                         }
 983                         break;
 984                     OPMEV_DEBUGMESSAGE(PMEV_POWERSTATECHANGE);
 985                         apm_record_event(sc, apm_event);
 986                         break;
 987                     OPMEV_DEBUGMESSAGE(PMEV_UPDATETIME);
 988                         apm_record_event(sc, apm_event);
 989                         inittodr(0);    /* adjust time to RTC */
 990                         break;
 991                     OPMEV_DEBUGMESSAGE(PMEV_CAPABILITIESCHANGE);
 992                         apm_record_event(sc, apm_event);
 993                         break;
 994                     case PMEV_NOEVENT:
 995                         break;
 996                     default:
 997                         printf("Unknown Original APM Event 0x%x\n", apm_event);
 998                             break;
 999                 }
1000         } while (apm_event != PMEV_NOEVENT);
1001 }
1002
1003 /*
1004  * Attach APM:
1005  *
1006  * Initialize APM driver
1007  */
1008
1009 static int
1010 apm_attach(device_t dev)
1011 {
1012         struct apm_softc        *sc = &apm_softc;
1013         int                     flags;
1014         int                     drv_version;
1015
1016         if (resource_int_value("apm", 0, "flags", &flags) != 0)
1017                 flags = 0;
1018
1019         sc->initialized = 0;
1020
1021         /* Must be externally enabled */
1022         sc->active = 0;
1023
1024         /* Always call HLT in idle loop */
1025         sc->always_halt_cpu = 1;
1026
1027         getenv_int("debug.apm_debug", &apm_debug);
1028
1029         /* print bootstrap messages */
1030         APM_DPRINT("apm: APM BIOS version %04lx\n",  apm_version);
1031         APM_DPRINT("apm: Code16 0x%08x, Data 0x%08x\n",
1032             sc->bios.seg.code16.base, sc->bios.seg.data.base);
1033         APM_DPRINT("apm: Code entry 0x%08x, Idling CPU %s, Management %s\n",
1034             sc->bios.entry, is_enabled(sc->slow_idle_cpu),
1035             is_enabled(!sc->disabled));
1036         APM_DPRINT("apm: CS_limit=0x%x, DS_limit=0x%x\n",
1037             sc->bios.seg.code16.limit, sc->bios.seg.data.limit);
1038
1039         /*
1040          * In one test, apm bios version was 1.02; an attempt to register
1041          * a 1.04 driver resulted in a 1.00 connection!  Registering a
1042          * 1.02 driver resulted in a 1.02 connection.
1043          */
1044         drv_version = apm_version > 0x102 ? 0x102 : apm_version;
1045         for (; drv_version > 0x100; drv_version--)
1046                 if (apm_driver_version(drv_version) == 0)
1047                         break;
1048         sc->minorversion = ((drv_version & 0x00f0) >>  4) * 10 +
1049                 ((drv_version & 0x000f) >> 0);
1050         sc->majorversion = ((drv_version & 0xf000) >> 12) * 10 +
1051                 ((apm_version & 0x0f00) >> 8);
1052
1053         sc->intversion = INTVERSION(sc->majorversion, sc->minorversion);
1054
1055         if (sc->intversion >= INTVERSION(1, 1))
1056                 APM_DPRINT("apm: Engaged control %s\n", is_enabled(!sc->disengaged));
1057         device_printf(dev, "found APM BIOS v%ld.%ld, connected at v%d.%d\n",
1058                ((apm_version & 0xf000) >> 12) * 10 + ((apm_version & 0x0f00) >> 8),
1059                ((apm_version & 0x00f0) >> 4) * 10 + ((apm_version & 0x000f) >> 0),
1060                sc->majorversion, sc->minorversion);
1061
1062
1063         APM_DPRINT("apm: Slow Idling CPU %s\n", is_enabled(sc->slow_idle_cpu));
1064         /* enable power management */
1065         if (sc->disabled) {
1066                 if (apm_enable_disable_pm(1)) {
1067                         APM_DPRINT("apm: *Warning* enable function failed! [%x]\n",
1068                             (sc->bios.r.eax >> 8) & 0xff);
1069                 }
1070         }
1071
1072         /* engage power managment (APM 1.1 or later) */
1073         if (sc->intversion >= INTVERSION(1, 1) && sc->disengaged) {
1074                 if (apm_engage_disengage_pm(1)) {
1075                         APM_DPRINT("apm: *Warning* engage function failed err=[%x]",
1076                             (sc->bios.r.eax >> 8) & 0xff);
1077                         APM_DPRINT(" (Docked or using external power?).\n");
1078                 }
1079         }
1080
1081         /* default suspend hook */
1082         sc->sc_suspend.ah_fun = apm_default_suspend;
1083         sc->sc_suspend.ah_arg = sc;
1084         sc->sc_suspend.ah_name = "default suspend";
1085         sc->sc_suspend.ah_order = APM_MAX_ORDER;
1086
1087         /* default resume hook */
1088         sc->sc_resume.ah_fun = apm_default_resume;
1089         sc->sc_resume.ah_arg = sc;
1090         sc->sc_resume.ah_name = "default resume";
1091         sc->sc_resume.ah_order = APM_MIN_ORDER;
1092
1093         apm_hook_establish(APM_HOOK_SUSPEND, &sc->sc_suspend);
1094         apm_hook_establish(APM_HOOK_RESUME , &sc->sc_resume);
1095
1096         /* Power the system off using APM */
1097         EVENTHANDLER_REGISTER(shutdown_final, apm_power_off, NULL,
1098                               SHUTDOWN_PRI_LAST);
1099
1100         sc->initialized = 1;
1101
1102         cdevsw_add(&apm_cdevsw, 0, 0);
1103         make_dev(&apm_cdevsw, 0, UID_ROOT, GID_OPERATOR, 0660, "apm");
1104         make_dev(&apm_cdevsw, 8, UID_ROOT, GID_OPERATOR, 0660, "apmctl");
1105         return 0;
1106 }
1107
1108 static int
1109 apmopen(dev_t dev, int flag, int fmt, d_thread_t *td)
1110 {
1111         struct apm_softc *sc = &apm_softc;
1112         int ctl = APMDEV(dev);
1113
1114         if (!sc->initialized)
1115                 return (ENXIO);
1116
1117         switch (ctl) {
1118         case APMDEV_CTL:
1119                 if (!(flag & FWRITE))
1120                         return EINVAL;
1121                 if (sc->sc_flags & SCFLAG_OCTL)
1122                         return EBUSY;
1123                 sc->sc_flags |= SCFLAG_OCTL;
1124                 bzero(sc->event_filter, sizeof sc->event_filter);
1125                 break;
1126         case APMDEV_NORMAL:
1127                 sc->sc_flags |= SCFLAG_ONORMAL;
1128                 break;
1129         default:
1130                 return ENXIO;
1131                 break;
1132         }
1133         return 0;
1134 }
1135
1136 static int
1137 apmclose(dev_t dev, int flag, int fmt, d_thread_t *td)
1138 {
1139         struct apm_softc *sc = &apm_softc;
1140         int ctl = APMDEV(dev);
1141
1142         switch (ctl) {
1143         case APMDEV_CTL:
1144                 apm_lastreq_rejected();
1145                 sc->sc_flags &= ~SCFLAG_OCTL;
1146                 bzero(sc->event_filter, sizeof sc->event_filter);
1147                 break;
1148         case APMDEV_NORMAL:
1149                 sc->sc_flags &= ~SCFLAG_ONORMAL;
1150                 break;
1151         }
1152         if ((sc->sc_flags & SCFLAG_OPEN) == 0) {
1153                 sc->event_count = 0;
1154                 sc->event_ptr = 0;
1155         }
1156         return 0;
1157 }
1158
1159 static int
1160 apmioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, d_thread_t *td)
1161 {
1162         struct apm_softc *sc = &apm_softc;
1163         struct apm_bios_arg *args;
1164         int error = 0;
1165         int ret;
1166         int newstate;
1167
1168         if (!sc->initialized)
1169                 return (ENXIO);
1170         APM_DPRINT("APM ioctl: cmd = 0x%lx\n", cmd);
1171         switch (cmd) {
1172         case APMIO_SUSPEND:
1173                 if (!(flag & FWRITE))
1174                         return (EPERM);
1175                 if (sc->active)
1176                         apm_suspend(PMST_SUSPEND);
1177                 else
1178                         error = EINVAL;
1179                 break;
1180
1181         case APMIO_STANDBY:
1182                 if (!(flag & FWRITE))
1183                         return (EPERM);
1184                 if (sc->active)
1185                         apm_suspend(PMST_STANDBY);
1186                 else
1187                         error = EINVAL;
1188                 break;
1189
1190         case APMIO_GETINFO_OLD:
1191                 {
1192                         struct apm_info info;
1193                         apm_info_old_t aiop;
1194
1195                         if (apm_get_info(&info))
1196                                 error = ENXIO;
1197                         aiop = (apm_info_old_t)addr;
1198                         aiop->ai_major = info.ai_major;
1199                         aiop->ai_minor = info.ai_minor;
1200                         aiop->ai_acline = info.ai_acline;
1201                         aiop->ai_batt_stat = info.ai_batt_stat;
1202                         aiop->ai_batt_life = info.ai_batt_life;
1203                         aiop->ai_status = info.ai_status;
1204                 }
1205                 break;
1206         case APMIO_GETINFO:
1207                 if (apm_get_info((apm_info_t)addr))
1208                         error = ENXIO;
1209                 break;
1210         case APMIO_GETPWSTATUS:
1211                 if (apm_get_pwstatus((apm_pwstatus_t)addr))
1212                         error = ENXIO;
1213                 break;
1214         case APMIO_ENABLE:
1215                 if (!(flag & FWRITE))
1216                         return (EPERM);
1217                 apm_event_enable();
1218                 break;
1219         case APMIO_DISABLE:
1220                 if (!(flag & FWRITE))
1221                         return (EPERM);
1222                 apm_event_disable();
1223                 break;
1224         case APMIO_HALTCPU:
1225                 if (!(flag & FWRITE))
1226                         return (EPERM);
1227                 apm_halt_cpu();
1228                 break;
1229         case APMIO_NOTHALTCPU:
1230                 if (!(flag & FWRITE))
1231                         return (EPERM);
1232                 apm_not_halt_cpu();
1233                 break;
1234         case APMIO_DISPLAY:
1235                 if (!(flag & FWRITE))
1236                         return (EPERM);
1237                 newstate = *(int *)addr;
1238                 if (apm_display(newstate))
1239                         error = ENXIO;
1240                 break;
1241         case APMIO_BIOS:
1242                 if (!(flag & FWRITE))
1243                         return (EPERM);
1244                 /* XXX compatibility with the old interface */
1245                 args = (struct apm_bios_arg *)addr;
1246                 sc->bios.r.eax = args->eax;
1247                 sc->bios.r.ebx = args->ebx;
1248                 sc->bios.r.ecx = args->ecx;
1249                 sc->bios.r.edx = args->edx;
1250                 sc->bios.r.esi = args->esi;
1251                 sc->bios.r.edi = args->edi;
1252                 if ((ret = apm_bioscall())) {
1253                         /*
1254                          * Return code 1 means bios call was unsuccessful.
1255                          * Error code is stored in %ah.
1256                          * Return code -1 means bios call was unsupported
1257                          * in the APM BIOS version.
1258                          */
1259                         if (ret == -1) {
1260                                 error = EINVAL;
1261                         }
1262                 } else {
1263                         /*
1264                          * Return code 0 means bios call was successful.
1265                          * We need only %al and can discard %ah.
1266                          */
1267                         sc->bios.r.eax &= 0xff;
1268                 }
1269                 args->eax = sc->bios.r.eax;
1270                 args->ebx = sc->bios.r.ebx;
1271                 args->ecx = sc->bios.r.ecx;
1272                 args->edx = sc->bios.r.edx;
1273                 args->esi = sc->bios.r.esi;
1274                 args->edi = sc->bios.r.edi;
1275                 break;
1276         default:
1277                 error = EINVAL;
1278                 break;
1279         }
1280
1281         /* for /dev/apmctl */
1282         if (APMDEV(dev) == APMDEV_CTL) {
1283                 struct apm_event_info *evp;
1284                 int i;
1285
1286                 error = 0;
1287                 switch (cmd) {
1288                 case APMIO_NEXTEVENT:
1289                         if (!sc->event_count) {
1290                                 error = EAGAIN;
1291                         } else {
1292                                 evp = (struct apm_event_info *)addr;
1293                                 i = sc->event_ptr + APM_NEVENTS - sc->event_count;
1294                                 i %= APM_NEVENTS;
1295                                 *evp = sc->event_list[i];
1296                                 sc->event_count--;
1297                         }
1298                         break;
1299                 case APMIO_REJECTLASTREQ:
1300                         if (apm_lastreq_rejected()) {
1301                                 error = EINVAL;
1302                         }
1303                         break;
1304                 default:
1305                         error = EINVAL;
1306                         break;
1307                 }
1308         }
1309
1310         return error;
1311 }
1312
1313 static int
1314 apmwrite(dev_t dev, struct uio *uio, int ioflag)
1315 {
1316         struct apm_softc *sc = &apm_softc;
1317         u_int event_type;
1318         int error;
1319         u_char enabled;
1320
1321         if (APMDEV(dev) != APMDEV_CTL)
1322                 return(ENODEV);
1323         if (uio->uio_resid != sizeof(u_int))
1324                 return(E2BIG);
1325
1326         if ((error = uiomove((caddr_t)&event_type, sizeof(u_int), uio)))
1327                 return(error);
1328
1329         if (event_type < 0 || event_type >= APM_NPMEV)
1330                 return(EINVAL);
1331
1332         if (sc->event_filter[event_type] == 0) {
1333                 enabled = 1;
1334         } else {
1335                 enabled = 0;
1336         }
1337         sc->event_filter[event_type] = enabled;
1338         APM_DPRINT("apmwrite: event 0x%x %s\n", event_type, is_enabled(enabled));
1339
1340         return uio->uio_resid;
1341 }
1342
1343 static int
1344 apmpoll(dev_t dev, int events, d_thread_t *td)
1345 {
1346         struct apm_softc *sc = &apm_softc;
1347         int revents = 0;
1348
1349         if (events & (POLLIN | POLLRDNORM)) {
1350                 if (sc->event_count) {
1351                         revents |= events & (POLLIN | POLLRDNORM);
1352                 } else {
1353                         selrecord(td, &sc->sc_rsel);
1354                 }
1355         }
1356
1357         return (revents);
1358 }
1359
1360 /*
1361  * Because apm is a static device that always exists under any attached
1362  * isa device, and not scanned by the isa device, we need an identify
1363  * function to install the device so we can probe for it.
1364  */
1365 static device_method_t apm_methods[] = {
1366         /* Device interface */
1367         DEVMETHOD(device_identify,      bus_generic_identify),
1368         DEVMETHOD(device_probe,         apm_probe),
1369         DEVMETHOD(device_attach,        apm_attach),
1370
1371         { 0, 0 }
1372 };
1373
1374 static driver_t apm_driver = {
1375         "apm",
1376         apm_methods,
1377         1,                      /* no softc (XXX) */
1378 };
1379
1380 static devclass_t apm_devclass;
1381
1382 DRIVER_MODULE(apm, nexus, apm_driver, apm_devclass, 0, 0);
1383