sys/platform/pc64/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  */
  20
  21 #include <sys/param.h>
  22 #include <sys/systm.h>
  23 #include <sys/eventhandler.h>
  24 #include <sys/conf.h>
  25 #include <sys/device.h>
  26 #include <sys/kernel.h>
  27 #include <sys/time.h>
  28 #include <sys/reboot.h>
  29 #include <sys/bus.h>
  30 #include <sys/event.h>
  31 #include <sys/fcntl.h>
  32 #include <sys/uio.h>
  33 #include <sys/signalvar.h>
  34 #include <sys/sysctl.h>
  35 #include <machine/apm_bios.h>
  36 #include <machine/segments.h>
  37 #include <machine/clock.h>
  38 #include <vm/vm.h>
  39 #include <vm/vm_param.h>
  40 #include <vm/pmap.h>
  41 #include <sys/syslog.h>
  42 #include <sys/thread2.h>
  43
  44 #include <machine/pc/bios.h>
  45 #include <machine/vm86.h>
  46
  47 #include <machine_base/apm/apm.h>
  48
  49 /* Used by the apm_saver screen saver module */
  50 int apm_display (int newstate);
  51 struct apm_softc apm_softc;
  52
  53 static void apm_resume (void);
  54 static int apm_bioscall(void);
  55 static int apm_check_function_supported (u_int version, u_int func);
  56
  57 static u_long   apm_version;
  58
  59 int     apm_evindex;
  60
  61 #define SCFLAG_ONORMAL  0x0000001
  62 #define SCFLAG_OCTL     0x0000002
  63 #define SCFLAG_OPEN     (SCFLAG_ONORMAL|SCFLAG_OCTL)
  64
  65 #define APMDEV(dev)     (minor(dev)&0x0f)
  66 #define APMDEV_NORMAL   0
  67 #define APMDEV_CTL      8
  68
  69 static struct apmhook   *hook[NAPM_HOOK];               /* XXX */
  70
  71 #define is_enabled(foo) ((foo) ? "enabled" : "disabled")
  72
  73 /* Map version number to integer (keeps ordering of version numbers) */
  74 #define INTVERSION(major, minor)        ((major)*100 + (minor))
  75
  76 static struct callout apm_timeout_ch;
  77
  78 static timeout_t apm_timeout;
  79 static d_open_t apmopen;
  80 static d_close_t apmclose;
  81 static d_write_t apmwrite;
  82 static d_ioctl_t apmioctl;
  83 static d_kqfilter_t apmkqfilter;
  84
  85 static void apmfilter_detach(struct knote *);
  86 static int apmfilter_read(struct knote *, long);
  87 static int apmfilter_write(struct knote *, long);
  88
  89 static struct dev_ops apm_ops = {
  90         { "apm", 0, 0 },
  91         .d_open =       apmopen,
  92         .d_close =      apmclose,
  93         .d_write =      apmwrite,
  94         .d_ioctl =      apmioctl,
  95         .d_kqfilter =   apmkqfilter
  96 };
  97
  98 static int apm_suspend_delay = 1;
  99 static int apm_standby_delay = 1;
 100 static int apm_debug = 0;
 101
 102 #define APM_DPRINT(args...) do  {                                       \
 103         if (apm_debug) {                                                \
 104                 kprintf(args);                                          \
 105         }                                                               \
 106 } while (0)
 107
 108 SYSCTL_INT(_machdep, OID_AUTO, apm_suspend_delay, CTLFLAG_RW, &apm_suspend_delay, 1, "");
 109 SYSCTL_INT(_machdep, OID_AUTO, apm_standby_delay, CTLFLAG_RW, &apm_standby_delay, 1, "");
 110 SYSCTL_INT(_debug, OID_AUTO, apm_debug, CTLFLAG_RW, &apm_debug, 0, "");
 111
 112 /*
 113  * return  0 if the function successfull,
 114  * return  1 if the function unsuccessfull,
 115  * return -1 if the function unsupported.
 116  */
 117 static int
 118 apm_bioscall(void)
 119 {
 120         struct apm_softc *sc = &apm_softc;
 121         int error = 0;
 122         u_int apm_func = sc->bios.r.eax & 0xff;
 123
 124         if (!apm_check_function_supported(sc->intversion, apm_func)) {
 125                 APM_DPRINT("apm_bioscall: function 0x%x is not supported in v%d.%d\n",
 126                     apm_func, sc->majorversion, sc->minorversion);
 127                 return (-1);
 128         }
 129
 130         sc->bios_busy = 1;
 131         if (sc->connectmode == APM_PROT32CONNECT) {
 132                 set_bios_selectors(&sc->bios.seg,
 133                                    BIOSCODE_FLAG | BIOSDATA_FLAG);
 134                 error = bios32(&sc->bios.r,
 135                                sc->bios.entry, GSEL(GBIOSCODE32_SEL, SEL_KPL));
 136         } else {
 137                 error = bios16(&sc->bios, NULL);
 138         }
 139         sc->bios_busy = 0;
 140         return (error);
 141 }
 142
 143 /* check whether APM function is supported (1)  or not (0). */
 144 static int
 145 apm_check_function_supported(u_int version, u_int func)
 146 {
 147         /* except driver version */
 148         if (func == APM_DRVVERSION) {
 149                 return (1);
 150         }
 151
 152         switch (version) {
 153         case INTVERSION(1, 0):
 154                 if (func > APM_GETPMEVENT) {
 155                         return (0); /* not supported */
 156                 }
 157                 break;
 158         case INTVERSION(1, 1):
 159                 if (func > APM_ENGAGEDISENGAGEPM &&
 160                     func < APM_OEMFUNC) {
 161                         return (0); /* not supported */
 162                 }
 163                 break;
 164         case INTVERSION(1, 2):
 165                 break;
 166         }
 167
 168         return (1); /* supported */
 169 }
 170
 171 /* enable/disable power management */
 172 static int
 173 apm_enable_disable_pm(int enable)
 174 {
 175         struct apm_softc *sc = &apm_softc;
 176
 177         sc->bios.r.eax = (APM_BIOS << 8) | APM_ENABLEDISABLEPM;
 178
 179         if (sc->intversion >= INTVERSION(1, 1))
 180                 sc->bios.r.ebx  = PMDV_ALLDEV;
 181         else
 182                 sc->bios.r.ebx  = 0xffff;       /* APM version 1.0 only */
 183         sc->bios.r.ecx  = enable;
 184         sc->bios.r.edx = 0;
 185         return (apm_bioscall());
 186 }
 187
 188 /* register driver version (APM 1.1 or later) */
 189 static int
 190 apm_driver_version(int version)
 191 {
 192         struct apm_softc *sc = &apm_softc;
 193
 194         sc->bios.r.eax = (APM_BIOS << 8) | APM_DRVVERSION;
 195         sc->bios.r.ebx  = 0x0;
 196         sc->bios.r.ecx  = version;
 197         sc->bios.r.edx = 0;
 198
 199         if (apm_bioscall() == 0 && sc->bios.r.eax == version)
 200                 return (0);
 201
 202         /* Some old BIOSes don't return the connection version in %ax. */
 203         if (sc->bios.r.eax == ((APM_BIOS << 8) | APM_DRVVERSION))
 204                 return (0);
 205
 206         return (1);
 207 }
 208
 209 /* engage/disengage power management (APM 1.1 or later) */
 210 static int
 211 apm_engage_disengage_pm(int engage)
 212 {
 213         struct apm_softc *sc = &apm_softc;
 214
 215         sc->bios.r.eax = (APM_BIOS << 8) | APM_ENGAGEDISENGAGEPM;
 216         sc->bios.r.ebx = PMDV_ALLDEV;
 217         sc->bios.r.ecx = engage;
 218         sc->bios.r.edx = 0;
 219         return (apm_bioscall());
 220 }
 221
 222 /* get PM event */
 223 static u_int
 224 apm_getevent(void)
 225 {
 226         struct apm_softc *sc = &apm_softc;
 227
 228         sc->bios.r.eax = (APM_BIOS << 8) | APM_GETPMEVENT;
 229
 230         sc->bios.r.ebx = 0;
 231         sc->bios.r.ecx = 0;
 232         sc->bios.r.edx = 0;
 233         if (apm_bioscall())
 234                 return (PMEV_NOEVENT);
 235         return (sc->bios.r.ebx & 0xffff);
 236 }
 237
 238 /* suspend entire system */
 239 static int
 240 apm_suspend_system(int state)
 241 {
 242         struct apm_softc *sc = &apm_softc;
 243
 244         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 245         sc->bios.r.ebx = PMDV_ALLDEV;
 246         sc->bios.r.ecx = state;
 247         sc->bios.r.edx = 0;
 248
 249         if (apm_bioscall()) {
 250                 kprintf("Entire system suspend failure: errcode = %d\n",
 251                         0xff & (sc->bios.r.eax >> 8));
 252                 return 1;
 253         }
 254         return 0;
 255 }
 256
 257 /* Display control */
 258 /*
 259  * Experimental implementation: My laptop machine can't handle this function
 260  * If your laptop can control the display via APM, please inform me.
 261  *                            HOSOKAWA, Tatsumi <hosokawa@jp.FreeBSD.org>
 262  */
 263 int
 264 apm_display(int newstate)
 265 {
 266         struct apm_softc *sc = &apm_softc;
 267
 268         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 269         sc->bios.r.ebx = PMDV_DISP0;
 270         sc->bios.r.ecx = newstate ? PMST_APMENABLED:PMST_SUSPEND;
 271         sc->bios.r.edx = 0;
 272         if (apm_bioscall() == 0) {
 273                 return 0;
 274         }
 275
 276         /* If failed, then try to blank all display devices instead. */
 277         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 278         sc->bios.r.ebx = PMDV_DISPALL;  /* all display devices */
 279         sc->bios.r.ecx = newstate ? PMST_APMENABLED:PMST_SUSPEND;
 280         sc->bios.r.edx = 0;
 281         if (apm_bioscall() == 0) {
 282                 return 0;
 283         }
 284         kprintf("Display off failure: errcode = %d\n",
 285                0xff & (sc->bios.r.eax >> 8));
 286         return 1;
 287 }
 288
 289 /*
 290  * Turn off the entire system.
 291  */
 292 static void
 293 apm_power_off(void *junk, int howto)
 294 {
 295         struct apm_softc *sc = &apm_softc;
 296
 297         /* Not halting powering off, or not active */
 298         if (!(howto & RB_POWEROFF) || !apm_softc.active)
 299                 return;
 300         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 301         sc->bios.r.ebx = PMDV_ALLDEV;
 302         sc->bios.r.ecx = PMST_OFF;
 303         sc->bios.r.edx = 0;
 304         apm_bioscall();
 305 }
 306
 307 /* APM Battery low handler */
 308 static void
 309 apm_battery_low(void)
 310 {
 311         kprintf("\007\007 * * * BATTERY IS LOW * * * \007\007");
 312 }
 313
 314 /* APM hook manager */
 315 static struct apmhook *
 316 apm_add_hook(struct apmhook **list, struct apmhook *ah)
 317 {
 318         struct apmhook *p, *prev;
 319
 320         APM_DPRINT("Add hook \"%s\"\n", ah->ah_name);
 321
 322         crit_enter();
 323         if (ah == NULL)
 324                 panic("illegal apm_hook!");
 325         prev = NULL;
 326         for (p = *list; p != NULL; prev = p, p = p->ah_next)
 327                 if (p->ah_order > ah->ah_order)
 328                         break;
 329
 330         if (prev == NULL) {
 331                 ah->ah_next = *list;
 332                 *list = ah;
 333         } else {
 334                 ah->ah_next = prev->ah_next;
 335                 prev->ah_next = ah;
 336         }
 337         crit_exit();
 338         return ah;
 339 }
 340
 341 static void
 342 apm_del_hook(struct apmhook **list, struct apmhook *ah)
 343 {
 344         struct apmhook *p, *prev;
 345
 346         crit_enter();
 347         prev = NULL;
 348         for (p = *list; p != NULL; prev = p, p = p->ah_next)
 349                 if (p == ah)
 350                         goto deleteit;
 351         panic("Tried to delete unregistered apm_hook.");
 352         goto nosuchnode;
 353 deleteit:
 354         if (prev != NULL)
 355                 prev->ah_next = p->ah_next;
 356         else
 357                 *list = p->ah_next;
 358 nosuchnode:
 359         crit_exit();
 360 }
 361
 362
 363 /* APM driver calls some functions automatically */
 364 static void
 365 apm_execute_hook(struct apmhook *list)
 366 {
 367         struct apmhook *p;
 368
 369         for (p = list; p != NULL; p = p->ah_next) {
 370                 APM_DPRINT("Execute APM hook \"%s.\"\n", p->ah_name);
 371                 if ((*(p->ah_fun))(p->ah_arg))
 372                         kprintf("Warning: APM hook \"%s\" failed", p->ah_name);
 373         }
 374 }
 375
 376
 377 /* establish an apm hook */
 378 struct apmhook *
 379 apm_hook_establish(int apmh, struct apmhook *ah)
 380 {
 381         if (apmh < 0 || apmh >= NAPM_HOOK)
 382                 return NULL;
 383
 384         return apm_add_hook(&hook[apmh], ah);
 385 }
 386
 387 /* disestablish an apm hook */
 388 void
 389 apm_hook_disestablish(int apmh, struct apmhook *ah)
 390 {
 391         if (apmh < 0 || apmh >= NAPM_HOOK)
 392                 return;
 393
 394         apm_del_hook(&hook[apmh], ah);
 395 }
 396
 397
 398 static struct timeval suspend_time;
 399 static struct timeval diff_time;
 400
 401 static int
 402 apm_default_resume(void *arg)
 403 {
 404         u_int second, minute, hour;
 405         struct timeval resume_time, tmp_time;
 406
 407         /* modified for adjkerntz */
 408         crit_enter();
 409         timer_restore();                /* restore the all timers */
 410         inittodr(0);                    /* adjust time to RTC */
 411         microtime(&resume_time);
 412         getmicrotime(&tmp_time);
 413         timevaladd(&tmp_time, &diff_time);
 414
 415 #ifdef FIXME
 416         /* XXX THIS DOESN'T WORK!!! */
 417         time = tmp_time;
 418 #endif
 419
 420 #ifdef APM_FIXUP_CALLTODO
 421         /* Calculate the delta time suspended */
 422         timevalsub(&resume_time, &suspend_time);
 423         /* Fixup the calltodo list with the delta time. */
 424         adjust_timeout_calltodo(&resume_time);
 425 #endif /* APM_FIXUP_CALLTODOK */
 426         crit_exit();
 427 #ifndef APM_FIXUP_CALLTODO
 428         second = resume_time.tv_sec - suspend_time.tv_sec;
 429 #else /* APM_FIXUP_CALLTODO */
 430         /*
 431          * We've already calculated resume_time to be the delta between
 432          * the suspend and the resume.
 433          */
 434         second = resume_time.tv_sec;
 435 #endif /* APM_FIXUP_CALLTODO */
 436         hour = second / 3600;
 437         second %= 3600;
 438         minute = second / 60;
 439         second %= 60;
 440         log(LOG_NOTICE, "resumed from suspended mode (slept %02d:%02d:%02d)\n",
 441                 hour, minute, second);
 442         return 0;
 443 }
 444
 445 static int
 446 apm_default_suspend(void *arg)
 447 {
 448         crit_enter();
 449         microtime(&diff_time);
 450         inittodr(0);
 451         microtime(&suspend_time);
 452         timevalsub(&diff_time, &suspend_time);
 453         crit_exit();
 454         return 0;
 455 }
 456
 457 static int apm_record_event (struct apm_softc *, u_int);
 458 static void apm_processevent(void);
 459
 460 static u_int apm_op_inprog = 0;
 461
 462 static void
 463 apm_do_suspend(void)
 464 {
 465         struct apm_softc *sc = &apm_softc;
 466         int error;
 467
 468         if (!sc)
 469                 return;
 470
 471         apm_op_inprog = 0;
 472         sc->suspends = sc->suspend_countdown = 0;
 473
 474         if (sc->initialized) {
 475                 error = DEVICE_SUSPEND(root_bus);
 476                 if (error) {
 477                         DEVICE_RESUME(root_bus);
 478                 } else {
 479                         apm_execute_hook(hook[APM_HOOK_SUSPEND]);
 480                         if (apm_suspend_system(PMST_SUSPEND) == 0) {
 481                                 apm_processevent();
 482                         } else {
 483                                 /* Failure, 'resume' the system again */
 484                                 apm_execute_hook(hook[APM_HOOK_RESUME]);
 485                                 DEVICE_RESUME(root_bus);
 486                         }
 487                 }
 488         }
 489 }
 490
 491 static void
 492 apm_do_standby(void)
 493 {
 494         struct apm_softc *sc = &apm_softc;
 495
 496         if (!sc)
 497                 return;
 498
 499         apm_op_inprog = 0;
 500         sc->standbys = sc->standby_countdown = 0;
 501
 502         if (sc->initialized) {
 503                 /*
 504                  * As far as standby, we don't need to execute
 505                  * all of suspend hooks.
 506                  */
 507                 apm_default_suspend(&apm_softc);
 508                 if (apm_suspend_system(PMST_STANDBY) == 0)
 509                         apm_processevent();
 510         }
 511 }
 512
 513 static void
 514 apm_lastreq_notify(void)
 515 {
 516         struct apm_softc *sc = &apm_softc;
 517
 518         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 519         sc->bios.r.ebx = PMDV_ALLDEV;
 520         sc->bios.r.ecx = PMST_LASTREQNOTIFY;
 521         sc->bios.r.edx = 0;
 522         apm_bioscall();
 523 }
 524
 525 static int
 526 apm_lastreq_rejected(void)
 527 {
 528         struct apm_softc *sc = &apm_softc;
 529
 530         if (apm_op_inprog == 0) {
 531                 return 1;       /* no operation in progress */
 532         }
 533
 534         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 535         sc->bios.r.ebx = PMDV_ALLDEV;
 536         sc->bios.r.ecx = PMST_LASTREQREJECT;
 537         sc->bios.r.edx = 0;
 538
 539         if (apm_bioscall()) {
 540                 APM_DPRINT("apm_lastreq_rejected: failed\n");
 541                 return 1;
 542         }
 543         apm_op_inprog = 0;
 544         return 0;
 545 }
 546
 547 /*
 548  * Public interface to the suspend/resume:
 549  *
 550  * Execute suspend and resume hook before and after sleep, respectively.
 551  *
 552  */
 553
 554 void
 555 apm_suspend(int state)
 556 {
 557         struct apm_softc *sc = &apm_softc;
 558
 559         if (!sc->initialized)
 560                 return;
 561
 562         switch (state) {
 563         case PMST_SUSPEND:
 564                 if (sc->suspends)
 565                         return;
 566                 sc->suspends++;
 567                 sc->suspend_countdown = apm_suspend_delay;
 568                 break;
 569         case PMST_STANDBY:
 570                 if (sc->standbys)
 571                         return;
 572                 sc->standbys++;
 573                 sc->standby_countdown = apm_standby_delay;
 574                 break;
 575         default:
 576                 kprintf("apm_suspend: Unknown Suspend state 0x%x\n", state);
 577                 return;
 578         }
 579
 580         apm_op_inprog++;
 581         apm_lastreq_notify();
 582 }
 583
 584 void
 585 apm_resume(void)
 586 {
 587         struct apm_softc *sc = &apm_softc;
 588
 589         if (!sc)
 590                 return;
 591
 592         if (sc->initialized) {
 593                 apm_execute_hook(hook[APM_HOOK_RESUME]);
 594                 DEVICE_RESUME(root_bus);
 595         }
 596 }
 597
 598
 599 /* get power status per battery */
 600 static int
 601 apm_get_pwstatus(apm_pwstatus_t app)
 602 {
 603         struct apm_softc *sc = &apm_softc;
 604
 605         if (app->ap_device != PMDV_ALLDEV &&
 606             (app->ap_device < PMDV_BATT0 || app->ap_device > PMDV_BATT_ALL))
 607                 return 1;
 608
 609         sc->bios.r.eax = (APM_BIOS << 8) | APM_GETPWSTATUS;
 610         sc->bios.r.ebx = app->ap_device;
 611         sc->bios.r.ecx = 0;
 612         sc->bios.r.edx = 0xffff;        /* default to unknown battery time */
 613
 614         if (apm_bioscall())
 615                 return 1;
 616
 617         app->ap_acline    = (sc->bios.r.ebx >> 8) & 0xff;
 618         app->ap_batt_stat = sc->bios.r.ebx & 0xff;
 619         app->ap_batt_flag = (sc->bios.r.ecx >> 8) & 0xff;
 620         app->ap_batt_life = sc->bios.r.ecx & 0xff;
 621         sc->bios.r.edx &= 0xffff;
 622         if (sc->bios.r.edx == 0xffff)   /* Time is unknown */
 623                 app->ap_batt_time = -1;
 624         else if (sc->bios.r.edx & 0x8000)       /* Time is in minutes */
 625                 app->ap_batt_time = (sc->bios.r.edx & 0x7fff) * 60;
 626         else                            /* Time is in seconds */
 627                 app->ap_batt_time = sc->bios.r.edx;
 628
 629         return 0;
 630 }
 631
 632
 633 /* get APM information */
 634 static int
 635 apm_get_info(apm_info_t aip)
 636 {
 637         struct apm_softc *sc = &apm_softc;
 638         struct apm_pwstatus aps;
 639
 640         bzero(&aps, sizeof(aps));
 641         aps.ap_device = PMDV_ALLDEV;
 642         if (apm_get_pwstatus(&aps))
 643                 return 1;
 644
 645         aip->ai_infoversion = 1;
 646         aip->ai_acline      = aps.ap_acline;
 647         aip->ai_batt_stat   = aps.ap_batt_stat;
 648         aip->ai_batt_life   = aps.ap_batt_life;
 649         aip->ai_batt_time   = aps.ap_batt_time;
 650         aip->ai_major       = (u_int)sc->majorversion;
 651         aip->ai_minor       = (u_int)sc->minorversion;
 652         aip->ai_status      = (u_int)sc->active;
 653
 654         sc->bios.r.eax = (APM_BIOS << 8) | APM_GETCAPABILITIES;
 655         sc->bios.r.ebx = 0;
 656         sc->bios.r.ecx = 0;
 657         sc->bios.r.edx = 0;
 658         if (apm_bioscall()) {
 659                 aip->ai_batteries = -1; /* Unknown */
 660                 aip->ai_capabilities = 0xff00; /* Unknown, with no bits set */
 661         } else {
 662                 aip->ai_batteries = sc->bios.r.ebx & 0xff;
 663                 aip->ai_capabilities = sc->bios.r.ecx & 0xf;
 664         }
 665
 666         bzero(aip->ai_spare, sizeof aip->ai_spare);
 667
 668         return 0;
 669 }
 670
 671
 672 /* inform APM BIOS that CPU is idle */
 673 void
 674 apm_cpu_idle(void)
 675 {
 676         struct apm_softc *sc = &apm_softc;
 677
 678         if (sc->active) {
 679
 680                 sc->bios.r.eax = (APM_BIOS <<8) | APM_CPUIDLE;
 681                 sc->bios.r.edx = sc->bios.r.ecx = sc->bios.r.ebx = 0;
 682                 apm_bioscall();
 683         }
 684         /*
 685          * Some APM implementation halts CPU in BIOS, whenever
 686          * "CPU-idle" function are invoked, but swtch() of
 687          * FreeBSD halts CPU, therefore, CPU is halted twice
 688          * in the sched loop. It makes the interrupt latency
 689          * terribly long and be able to cause a serious problem
 690          * in interrupt processing. We prevent it by removing
 691          * "hlt" operation from swtch() and managed it under
 692          * APM driver.
 693          */
 694         if (!sc->active || sc->always_halt_cpu)
 695                 __asm("hlt");   /* wait for interrupt */
 696 }
 697
 698 /* inform APM BIOS that CPU is busy */
 699 void
 700 apm_cpu_busy(void)
 701 {
 702         struct apm_softc *sc = &apm_softc;
 703
 704         /*
 705          * The APM specification says this is only necessary if your BIOS
 706          * slows down the processor in the idle task, otherwise it's not
 707          * necessary.
 708          */
 709         if (sc->slow_idle_cpu && sc->active) {
 710
 711                 sc->bios.r.eax = (APM_BIOS <<8) | APM_CPUBUSY;
 712                 sc->bios.r.edx = sc->bios.r.ecx = sc->bios.r.ebx = 0;
 713                 apm_bioscall();
 714         }
 715 }
 716
 717
 718 /*
 719  * APM timeout routine:
 720  *
 721  * This routine is automatically called by timer once per second.
 722  */
 723
 724 static void
 725 apm_timeout(void *dummy)
 726 {
 727         struct apm_softc *sc = &apm_softc;
 728
 729         if (apm_op_inprog)
 730                 apm_lastreq_notify();
 731
 732         if (sc->standbys && sc->standby_countdown-- <= 0)
 733                 apm_do_standby();
 734
 735         if (sc->suspends && sc->suspend_countdown-- <= 0)
 736                 apm_do_suspend();
 737
 738         if (!sc->bios_busy)
 739                 apm_processevent();
 740
 741         if (sc->active == 1) {
 742                 /* Run slightly more oftan than 1 Hz */
 743                 callout_reset(&apm_timeout_ch, hz - 1, apm_timeout, NULL);
 744         }
 745 }
 746
 747 /* enable APM BIOS */
 748 static void
 749 apm_event_enable(void)
 750 {
 751         struct apm_softc *sc = &apm_softc;
 752
 753         APM_DPRINT("called apm_event_enable()\n");
 754         if (sc->initialized) {
 755                 sc->active = 1;
 756                 callout_init(&apm_timeout_ch);
 757                 apm_timeout(sc);
 758         }
 759 }
 760
 761 /* disable APM BIOS */
 762 static void
 763 apm_event_disable(void)
 764 {
 765         struct apm_softc *sc = &apm_softc;
 766
 767         APM_DPRINT("called apm_event_disable()\n");
 768         if (sc->initialized) {
 769                 callout_stop(&apm_timeout_ch);
 770                 sc->active = 0;
 771         }
 772 }
 773
 774 /* halt CPU in scheduling loop */
 775 static void
 776 apm_halt_cpu(void)
 777 {
 778         struct apm_softc *sc = &apm_softc;
 779
 780         if (sc->initialized)
 781                 sc->always_halt_cpu = 1;
 782 }
 783
 784 /* don't halt CPU in scheduling loop */
 785 static void
 786 apm_not_halt_cpu(void)
 787 {
 788         struct apm_softc *sc = &apm_softc;
 789
 790         if (sc->initialized)
 791                 sc->always_halt_cpu = 0;
 792 }
 793
 794 /* device driver definitions */
 795
 796 /*
 797  * probe for APM BIOS
 798  */
 799 static int
 800 apm_probe(device_t dev)
 801 {
 802 #define APM_KERNBASE    KERNBASE
 803         struct vm86frame        vmf;
 804         struct apm_softc        *sc = &apm_softc;
 805         int                     disabled, flags;
 806
 807         if (resource_int_value("apm", 0, "disabled", &disabled) == 0
 808             && disabled != 0)
 809                 return ENXIO;
 810
 811         device_set_desc(dev, "APM BIOS");
 812
 813         if ( device_get_unit(dev) > 0 ) {
 814                 kprintf("apm: Only one APM driver supported.\n");
 815                 return ENXIO;
 816         }
 817
 818         if (resource_int_value("apm", 0, "flags", &flags) != 0)
 819                 flags = 0;
 820
 821         bzero(&vmf, sizeof(struct vm86frame));          /* safety */
 822         bzero(&apm_softc, sizeof(apm_softc));
 823         vmf.vmf_ah = APM_BIOS;
 824         vmf.vmf_al = APM_INSTCHECK;
 825         vmf.vmf_bx = 0;
 826         if (vm86_intcall(APM_INT, &vmf))
 827                 return ENXIO;                   /* APM not found */
 828         if (vmf.vmf_bx != 0x504d) {
 829                 kprintf("apm: incorrect signature (0x%x)\n", vmf.vmf_bx);
 830                 return ENXIO;
 831         }
 832         if ((vmf.vmf_cx & (APM_32BIT_SUPPORT | APM_16BIT_SUPPORT)) == 0) {
 833                 kprintf("apm: protected mode connections are not supported\n");
 834                 return ENXIO;
 835         }
 836
 837         apm_version = vmf.vmf_ax;
 838         sc->slow_idle_cpu = ((vmf.vmf_cx & APM_CPUIDLE_SLOW) != 0);
 839         sc->disabled = ((vmf.vmf_cx & APM_DISABLED) != 0);
 840         sc->disengaged = ((vmf.vmf_cx & APM_DISENGAGED) != 0);
 841
 842         vmf.vmf_ah = APM_BIOS;
 843         vmf.vmf_al = APM_DISCONNECT;
 844         vmf.vmf_bx = 0;
 845         vm86_intcall(APM_INT, &vmf);            /* disconnect, just in case */
 846
 847         if ((vmf.vmf_cx & APM_32BIT_SUPPORT) != 0) {
 848                 vmf.vmf_ah = APM_BIOS;
 849                 vmf.vmf_al = APM_PROT32CONNECT;
 850                 vmf.vmf_bx = 0;
 851                 if (vm86_intcall(APM_INT, &vmf)) {
 852                         kprintf("apm: 32-bit connection error.\n");
 853                         return (ENXIO);
 854                 }
 855                 sc->bios.seg.code32.base = (vmf.vmf_ax << 4) + APM_KERNBASE;
 856                 sc->bios.seg.code32.limit = 0xffff;
 857                 sc->bios.seg.code16.base = (vmf.vmf_cx << 4) + APM_KERNBASE;
 858                 sc->bios.seg.code16.limit = 0xffff;
 859                 sc->bios.seg.data.base = (vmf.vmf_dx << 4) + APM_KERNBASE;
 860                 sc->bios.seg.data.limit = 0xffff;
 861                 sc->bios.entry = vmf.vmf_ebx;
 862                 sc->connectmode = APM_PROT32CONNECT;
 863         } else {
 864                 /* use 16-bit connection */
 865                 vmf.vmf_ah = APM_BIOS;
 866                 vmf.vmf_al = APM_PROT16CONNECT;
 867                 vmf.vmf_bx = 0;
 868                 if (vm86_intcall(APM_INT, &vmf)) {
 869                         kprintf("apm: 16-bit connection error.\n");
 870                         return (ENXIO);
 871                 }
 872                 sc->bios.seg.code16.base = (vmf.vmf_ax << 4) + APM_KERNBASE;
 873                 sc->bios.seg.code16.limit = 0xffff;
 874                 sc->bios.seg.data.base = (vmf.vmf_cx << 4) + APM_KERNBASE;
 875                 sc->bios.seg.data.limit = 0xffff;
 876                 sc->bios.entry = vmf.vmf_bx;
 877                 sc->connectmode = APM_PROT16CONNECT;
 878         }
 879         return(0);
 880 }
 881
 882
 883 /*
 884  * return 0 if the user will notice and handle the event,
 885  * return 1 if the kernel driver should do so.
 886  */
 887 static int
 888 apm_record_event(struct apm_softc *sc, u_int event_type)
 889 {
 890         struct apm_event_info *evp;
 891
 892         if ((sc->sc_flags & SCFLAG_OPEN) == 0)
 893                 return 1;               /* no user waiting */
 894         if (sc->event_count == APM_NEVENTS)
 895                 return 1;                       /* overflow */
 896         if (sc->event_filter[event_type] == 0)
 897                 return 1;               /* not registered */
 898         evp = &sc->event_list[sc->event_ptr];
 899         sc->event_count++;
 900         sc->event_ptr++;
 901         sc->event_ptr %= APM_NEVENTS;
 902         evp->type = event_type;
 903         evp->index = ++apm_evindex;
 904         KNOTE(&sc->sc_rkq.ki_note, 0);
 905         return (sc->sc_flags & SCFLAG_OCTL) ? 0 : 1; /* user may handle */
 906 }
 907
 908 /* Process APM event */
 909 static void
 910 apm_processevent(void)
 911 {
 912         int apm_event;
 913         struct apm_softc *sc = &apm_softc;
 914
 915 #define OPMEV_DEBUGMESSAGE(symbol) case symbol:                         \
 916         APM_DPRINT("Received APM Event: " #symbol "\n");
 917
 918         do {
 919                 apm_event = apm_getevent();
 920                 switch (apm_event) {
 921                     OPMEV_DEBUGMESSAGE(PMEV_STANDBYREQ);
 922                         if (apm_op_inprog == 0) {
 923                             apm_op_inprog++;
 924                             if (apm_record_event(sc, apm_event)) {
 925                                 apm_suspend(PMST_STANDBY);
 926                             }
 927                         }
 928                         break;
 929                     OPMEV_DEBUGMESSAGE(PMEV_USERSTANDBYREQ);
 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_SUSPENDREQ);
 938                         apm_lastreq_notify();
 939                         if (apm_op_inprog == 0) {
 940                             apm_op_inprog++;
 941                             if (apm_record_event(sc, apm_event)) {
 942                                 apm_do_suspend();
 943                             }
 944                         }
 945                         return; /* XXX skip the rest */
 946                     OPMEV_DEBUGMESSAGE(PMEV_USERSUSPENDREQ);
 947                         apm_lastreq_notify();
 948                         if (apm_op_inprog == 0) {
 949                             apm_op_inprog++;
 950                             if (apm_record_event(sc, apm_event)) {
 951                                 apm_do_suspend();
 952                             }
 953                         }
 954                         return; /* XXX skip the rest */
 955                     OPMEV_DEBUGMESSAGE(PMEV_CRITSUSPEND);
 956                         apm_do_suspend();
 957                         break;
 958                     OPMEV_DEBUGMESSAGE(PMEV_NORMRESUME);
 959                         apm_record_event(sc, apm_event);
 960                         apm_resume();
 961                         break;
 962                     OPMEV_DEBUGMESSAGE(PMEV_CRITRESUME);
 963                         apm_record_event(sc, apm_event);
 964                         apm_resume();
 965                         break;
 966                     OPMEV_DEBUGMESSAGE(PMEV_STANDBYRESUME);
 967                         apm_record_event(sc, apm_event);
 968                         apm_resume();
 969                         break;
 970                     OPMEV_DEBUGMESSAGE(PMEV_BATTERYLOW);
 971                         if (apm_record_event(sc, apm_event)) {
 972                             apm_battery_low();
 973                             apm_suspend(PMST_SUSPEND);
 974                         }
 975                         break;
 976                     OPMEV_DEBUGMESSAGE(PMEV_POWERSTATECHANGE);
 977                         apm_record_event(sc, apm_event);
 978                         break;
 979                     OPMEV_DEBUGMESSAGE(PMEV_UPDATETIME);
 980                         apm_record_event(sc, apm_event);
 981                         inittodr(0);    /* adjust time to RTC */
 982                         break;
 983                     OPMEV_DEBUGMESSAGE(PMEV_CAPABILITIESCHANGE);
 984                         apm_record_event(sc, apm_event);
 985                         break;
 986                     case PMEV_NOEVENT:
 987                         break;
 988                     default:
 989                         kprintf("Unknown Original APM Event 0x%x\n", apm_event);
 990                             break;
 991                 }
 992         } while (apm_event != PMEV_NOEVENT);
 993 }
 994
 995 /*
 996  * Attach APM:
 997  *
 998  * Initialize APM driver
 999  */
1000
1001 static int
1002 apm_attach(device_t dev)
1003 {
1004         struct apm_softc        *sc = &apm_softc;
1005         int                     flags;
1006         int                     drv_version;
1007
1008         if (resource_int_value("apm", 0, "flags", &flags) != 0)
1009                 flags = 0;
1010
1011         sc->initialized = 0;
1012
1013         /* Must be externally enabled */
1014         sc->active = 0;
1015
1016         /* Always call HLT in idle loop */
1017         sc->always_halt_cpu = 1;
1018
1019         kgetenv_int("debug.apm_debug", &apm_debug);
1020
1021         /* print bootstrap messages */
1022         APM_DPRINT("apm: APM BIOS version %04lx\n",  apm_version);
1023         APM_DPRINT("apm: Code16 0x%08x, Data 0x%08x\n",
1024             sc->bios.seg.code16.base, sc->bios.seg.data.base);
1025         APM_DPRINT("apm: Code entry 0x%08x, Idling CPU %s, Management %s\n",
1026             sc->bios.entry, is_enabled(sc->slow_idle_cpu),
1027             is_enabled(!sc->disabled));
1028         APM_DPRINT("apm: CS_limit=0x%x, DS_limit=0x%x\n",
1029             sc->bios.seg.code16.limit, sc->bios.seg.data.limit);
1030
1031         /*
1032          * In one test, apm bios version was 1.02; an attempt to register
1033          * a 1.04 driver resulted in a 1.00 connection!  Registering a
1034          * 1.02 driver resulted in a 1.02 connection.
1035          */
1036         drv_version = apm_version > 0x102 ? 0x102 : apm_version;
1037         for (; drv_version > 0x100; drv_version--)
1038                 if (apm_driver_version(drv_version) == 0)
1039                         break;
1040         sc->minorversion = ((drv_version & 0x00f0) >>  4) * 10 +
1041                 ((drv_version & 0x000f) >> 0);
1042         sc->majorversion = ((drv_version & 0xf000) >> 12) * 10 +
1043                 ((apm_version & 0x0f00) >> 8);
1044
1045         sc->intversion = INTVERSION(sc->majorversion, sc->minorversion);
1046
1047         if (sc->intversion >= INTVERSION(1, 1))
1048                 APM_DPRINT("apm: Engaged control %s\n", is_enabled(!sc->disengaged));
1049         device_printf(dev, "found APM BIOS v%ld.%ld, connected at v%d.%d\n",
1050                ((apm_version & 0xf000) >> 12) * 10 + ((apm_version & 0x0f00) >> 8),
1051                ((apm_version & 0x00f0) >> 4) * 10 + ((apm_version & 0x000f) >> 0),
1052                sc->majorversion, sc->minorversion);
1053
1054
1055         APM_DPRINT("apm: Slow Idling CPU %s\n", is_enabled(sc->slow_idle_cpu));
1056         /* enable power management */
1057         if (sc->disabled) {
1058                 if (apm_enable_disable_pm(1)) {
1059                         APM_DPRINT("apm: *Warning* enable function failed! [%x]\n",
1060                             (sc->bios.r.eax >> 8) & 0xff);
1061                 }
1062         }
1063
1064         /* engage power managment (APM 1.1 or later) */
1065         if (sc->intversion >= INTVERSION(1, 1) && sc->disengaged) {
1066                 if (apm_engage_disengage_pm(1)) {
1067                         APM_DPRINT("apm: *Warning* engage function failed err=[%x]",
1068                             (sc->bios.r.eax >> 8) & 0xff);
1069                         APM_DPRINT(" (Docked or using external power?).\n");
1070                 }
1071         }
1072
1073         /* default suspend hook */
1074         sc->sc_suspend.ah_fun = apm_default_suspend;
1075         sc->sc_suspend.ah_arg = sc;
1076         sc->sc_suspend.ah_name = "default suspend";
1077         sc->sc_suspend.ah_order = APM_MAX_ORDER;
1078
1079         /* default resume hook */
1080         sc->sc_resume.ah_fun = apm_default_resume;
1081         sc->sc_resume.ah_arg = sc;
1082         sc->sc_resume.ah_name = "default resume";
1083         sc->sc_resume.ah_order = APM_MIN_ORDER;
1084
1085         apm_hook_establish(APM_HOOK_SUSPEND, &sc->sc_suspend);
1086         apm_hook_establish(APM_HOOK_RESUME , &sc->sc_resume);
1087
1088         /* Power the system off using APM */
1089         EVENTHANDLER_REGISTER(shutdown_final, apm_power_off, NULL,
1090                               SHUTDOWN_PRI_LAST);
1091
1092         sc->initialized = 1;
1093
1094         make_dev(&apm_ops, 0, UID_ROOT, GID_OPERATOR, 0660, "apm");
1095         make_dev(&apm_ops, 8, UID_ROOT, GID_OPERATOR, 0660, "apmctl");
1096         return 0;
1097 }
1098
1099 static int
1100 apmopen(struct dev_open_args *ap)
1101 {
1102         cdev_t dev = ap->a_head.a_dev;
1103         struct apm_softc *sc = &apm_softc;
1104         int ctl = APMDEV(dev);
1105
1106         if (!sc->initialized)
1107                 return (ENXIO);
1108
1109         switch (ctl) {
1110         case APMDEV_CTL:
1111                 if (!(ap->a_oflags & FWRITE))
1112                         return EINVAL;
1113                 if (sc->sc_flags & SCFLAG_OCTL)
1114                         return EBUSY;
1115                 sc->sc_flags |= SCFLAG_OCTL;
1116                 bzero(sc->event_filter, sizeof sc->event_filter);
1117                 break;
1118         case APMDEV_NORMAL:
1119                 sc->sc_flags |= SCFLAG_ONORMAL;
1120                 break;
1121         default:
1122                 return ENXIO;
1123                 break;
1124         }
1125         return 0;
1126 }
1127
1128 static int
1129 apmclose(struct dev_close_args *ap)
1130 {
1131         cdev_t dev = ap->a_head.a_dev;
1132         struct apm_softc *sc = &apm_softc;
1133         int ctl = APMDEV(dev);
1134
1135         switch (ctl) {
1136         case APMDEV_CTL:
1137                 apm_lastreq_rejected();
1138                 sc->sc_flags &= ~SCFLAG_OCTL;
1139                 bzero(sc->event_filter, sizeof sc->event_filter);
1140                 break;
1141         case APMDEV_NORMAL:
1142                 sc->sc_flags &= ~SCFLAG_ONORMAL;
1143                 break;
1144         }
1145         if ((sc->sc_flags & SCFLAG_OPEN) == 0) {
1146                 sc->event_count = 0;
1147                 sc->event_ptr = 0;
1148         }
1149         return 0;
1150 }
1151
1152 static int
1153 apmioctl(struct dev_ioctl_args *ap)
1154 {
1155         cdev_t dev = ap->a_head.a_dev;
1156         struct apm_softc *sc = &apm_softc;
1157         struct apm_bios_arg *args;
1158         int error = 0;
1159         int ret;
1160         int newstate;
1161
1162         if (!sc->initialized)
1163                 return (ENXIO);
1164         APM_DPRINT("APM ioctl: cmd = 0x%lx\n", ap->a_cmd);
1165
1166         switch (ap->a_cmd) {
1167         case APMIO_SUSPEND:
1168                 if (!(ap->a_fflag & FWRITE))
1169                         return (EPERM);
1170                 if (sc->active)
1171                         apm_suspend(PMST_SUSPEND);
1172                 else
1173                         error = EINVAL;
1174                 break;
1175
1176         case APMIO_STANDBY:
1177                 if (!(ap->a_fflag & FWRITE))
1178                         return (EPERM);
1179                 if (sc->active)
1180                         apm_suspend(PMST_STANDBY);
1181                 else
1182                         error = EINVAL;
1183                 break;
1184
1185         case APMIO_GETINFO_OLD:
1186                 {
1187                         struct apm_info info;
1188                         apm_info_old_t aiop;
1189
1190                         if (apm_get_info(&info))
1191                                 error = ENXIO;
1192                         aiop = (apm_info_old_t)ap->a_data;
1193                         aiop->ai_major = info.ai_major;
1194                         aiop->ai_minor = info.ai_minor;
1195                         aiop->ai_acline = info.ai_acline;
1196                         aiop->ai_batt_stat = info.ai_batt_stat;
1197                         aiop->ai_batt_life = info.ai_batt_life;
1198                         aiop->ai_status = info.ai_status;
1199                 }
1200                 break;
1201         case APMIO_GETINFO:
1202                 if (apm_get_info((apm_info_t)ap->a_data))
1203                         error = ENXIO;
1204                 break;
1205         case APMIO_GETPWSTATUS:
1206                 if (apm_get_pwstatus((apm_pwstatus_t)ap->a_data))
1207                         error = ENXIO;
1208                 break;
1209         case APMIO_ENABLE:
1210                 if (!(ap->a_fflag & FWRITE))
1211                         return (EPERM);
1212                 apm_event_enable();
1213                 break;
1214         case APMIO_DISABLE:
1215                 if (!(ap->a_fflag & FWRITE))
1216                         return (EPERM);
1217                 apm_event_disable();
1218                 break;
1219         case APMIO_HALTCPU:
1220                 if (!(ap->a_fflag & FWRITE))
1221                         return (EPERM);
1222                 apm_halt_cpu();
1223                 break;
1224         case APMIO_NOTHALTCPU:
1225                 if (!(ap->a_fflag & FWRITE))
1226                         return (EPERM);
1227                 apm_not_halt_cpu();
1228                 break;
1229         case APMIO_DISPLAY:
1230                 if (!(ap->a_fflag & FWRITE))
1231                         return (EPERM);
1232                 newstate = *(int *)ap->a_data;
1233                 if (apm_display(newstate))
1234                         error = ENXIO;
1235                 break;
1236         case APMIO_BIOS:
1237                 if (!(ap->a_fflag & FWRITE))
1238                         return (EPERM);
1239                 /* XXX compatibility with the old interface */
1240                 args = (struct apm_bios_arg *)ap->a_data;
1241                 sc->bios.r.eax = args->eax;
1242                 sc->bios.r.ebx = args->ebx;
1243                 sc->bios.r.ecx = args->ecx;
1244                 sc->bios.r.edx = args->edx;
1245                 sc->bios.r.esi = args->esi;
1246                 sc->bios.r.edi = args->edi;
1247                 if ((ret = apm_bioscall())) {
1248                         /*
1249                          * Return code 1 means bios call was unsuccessful.
1250                          * Error code is stored in %ah.
1251                          * Return code -1 means bios call was unsupported
1252                          * in the APM BIOS version.
1253                          */
1254                         if (ret == -1) {
1255                                 error = EINVAL;
1256                         }
1257                 } else {
1258                         /*
1259                          * Return code 0 means bios call was successful.
1260                          * We need only %al and can discard %ah.
1261                          */
1262                         sc->bios.r.eax &= 0xff;
1263                 }
1264                 args->eax = sc->bios.r.eax;
1265                 args->ebx = sc->bios.r.ebx;
1266                 args->ecx = sc->bios.r.ecx;
1267                 args->edx = sc->bios.r.edx;
1268                 args->esi = sc->bios.r.esi;
1269                 args->edi = sc->bios.r.edi;
1270                 break;
1271         default:
1272                 error = EINVAL;
1273                 break;
1274         }
1275
1276         /* for /dev/apmctl */
1277         if (APMDEV(dev) == APMDEV_CTL) {
1278                 struct apm_event_info *evp;
1279                 int i;
1280
1281                 error = 0;
1282                 switch (ap->a_cmd) {
1283                 case APMIO_NEXTEVENT:
1284                         if (!sc->event_count) {
1285                                 error = EAGAIN;
1286                         } else {
1287                                 evp = (struct apm_event_info *)ap->a_data;
1288                                 i = sc->event_ptr + APM_NEVENTS - sc->event_count;
1289                                 i %= APM_NEVENTS;
1290                                 *evp = sc->event_list[i];
1291                                 sc->event_count--;
1292                         }
1293                         break;
1294                 case APMIO_REJECTLASTREQ:
1295                         if (apm_lastreq_rejected()) {
1296                                 error = EINVAL;
1297                         }
1298                         break;
1299                 default:
1300                         error = EINVAL;
1301                         break;
1302                 }
1303         }
1304
1305         return error;
1306 }
1307
1308 static int
1309 apmwrite(struct dev_write_args *ap)
1310 {
1311         cdev_t dev = ap->a_head.a_dev;
1312         struct uio *uio = ap->a_uio;
1313         struct apm_softc *sc = &apm_softc;
1314         u_int event_type;
1315         int error;
1316         u_char enabled;
1317
1318         if (APMDEV(dev) != APMDEV_CTL)
1319                 return(ENODEV);
1320         if (uio->uio_resid != sizeof(u_int))
1321                 return(E2BIG);
1322
1323         if ((error = uiomove((caddr_t)&event_type, sizeof(u_int), uio)))
1324                 return(error);
1325
1326         if (event_type < 0 || event_type >= APM_NPMEV)
1327                 return(EINVAL);
1328
1329         if (sc->event_filter[event_type] == 0) {
1330                 enabled = 1;
1331         } else {
1332                 enabled = 0;
1333         }
1334         sc->event_filter[event_type] = enabled;
1335         APM_DPRINT("apmwrite: event 0x%x %s\n", event_type, is_enabled(enabled));
1336
1337         return uio->uio_resid;
1338 }
1339
1340 static struct filterops apmfiltops_read =
1341         { FILTEROP_ISFD, NULL, apmfilter_detach, apmfilter_read };
1342 static struct filterops apmfiltops_write =
1343         { FILTEROP_ISFD, NULL, apmfilter_detach, apmfilter_write };
1344
1345 static int
1346 apmkqfilter(struct dev_kqfilter_args *ap)
1347 {
1348         struct apm_softc *sc = &apm_softc;
1349         struct knote *kn = ap->a_kn;
1350         struct klist *klist;
1351
1352         ap->a_result = 0;
1353
1354         switch (kn->kn_filter) {
1355         case EVFILT_READ:
1356                 kn->kn_fop = &apmfiltops_read;
1357                 kn->kn_hook = (caddr_t)sc;
1358                 break;
1359         case EVFILT_WRITE:
1360                 kn->kn_fop = &apmfiltops_write;
1361                 kn->kn_hook = (caddr_t)sc;
1362                 break;
1363         default:
1364                 ap->a_result = EOPNOTSUPP;
1365                 return (0);
1366         }
1367
1368         klist = &sc->sc_rkq.ki_note;
1369         knote_insert(klist, kn);
1370
1371         return (0);
1372 }
1373
1374 static void
1375 apmfilter_detach(struct knote *kn)
1376 {
1377         struct apm_softc *sc = (struct apm_softc *)kn->kn_hook;
1378         struct klist *klist;
1379
1380         klist = &sc->sc_rkq.ki_note;
1381         knote_remove(klist, kn);
1382 }
1383
1384 static int
1385 apmfilter_read(struct knote *kn, long hint)
1386 {
1387         struct apm_softc *sc = (struct apm_softc *)kn->kn_hook;
1388         int ready = 0;
1389
1390         if (sc->event_count)
1391                 ready = 1;
1392
1393         return (ready);
1394 }
1395
1396 static int
1397 apmfilter_write(struct knote *kn, long hint)
1398 {
1399         /* write()'s are always OK */
1400         return (1);
1401 }
1402
1403 /*
1404  * Because apm is a static device that always exists under any attached
1405  * isa device, and not scanned by the isa device, we need an identify
1406  * function to install the device so we can probe for it.
1407  */
1408 static device_method_t apm_methods[] = {
1409         /* Device interface */
1410         DEVMETHOD(device_identify,      bus_generic_identify),
1411         DEVMETHOD(device_probe,         apm_probe),
1412         DEVMETHOD(device_attach,        apm_attach),
1413
1414         { 0, 0 }
1415 };
1416
1417 static driver_t apm_driver = {
1418         "apm",
1419         apm_methods,
1420         1,                      /* no softc (XXX) */
1421 };
1422
1423 static devclass_t apm_devclass;
1424
1425 DRIVER_MODULE(apm, nexus, apm_driver, apm_devclass, 0, 0);