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  */
  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     "Enable debug output");
 112
 113 /*
 114  * return  0 if the function successfull,
 115  * return  1 if the function unsuccessfull,
 116  * return -1 if the function unsupported.
 117  */
 118 static int
 119 apm_bioscall(void)
 120 {
 121         struct apm_softc *sc = &apm_softc;
 122         int error = 0;
 123         u_int apm_func = sc->bios.r.eax & 0xff;
 124
 125         if (!apm_check_function_supported(sc->intversion, apm_func)) {
 126                 APM_DPRINT("apm_bioscall: function 0x%x is not supported in v%d.%d\n",
 127                     apm_func, sc->majorversion, sc->minorversion);
 128                 return (-1);
 129         }
 130
 131         sc->bios_busy = 1;
 132         if (sc->connectmode == APM_PROT32CONNECT) {
 133                 set_bios_selectors(&sc->bios.seg,
 134                                    BIOSCODE_FLAG | BIOSDATA_FLAG);
 135                 error = bios32(&sc->bios.r,
 136                                sc->bios.entry, GSEL(GBIOSCODE32_SEL, SEL_KPL));
 137         } else {
 138                 error = bios16(&sc->bios, NULL);
 139         }
 140         sc->bios_busy = 0;
 141         return (error);
 142 }
 143
 144 /* check whether APM function is supported (1)  or not (0). */
 145 static int
 146 apm_check_function_supported(u_int version, u_int func)
 147 {
 148         /* except driver version */
 149         if (func == APM_DRVVERSION) {
 150                 return (1);
 151         }
 152
 153         switch (version) {
 154         case INTVERSION(1, 0):
 155                 if (func > APM_GETPMEVENT) {
 156                         return (0); /* not supported */
 157                 }
 158                 break;
 159         case INTVERSION(1, 1):
 160                 if (func > APM_ENGAGEDISENGAGEPM &&
 161                     func < APM_OEMFUNC) {
 162                         return (0); /* not supported */
 163                 }
 164                 break;
 165         case INTVERSION(1, 2):
 166                 break;
 167         }
 168
 169         return (1); /* supported */
 170 }
 171
 172 /* enable/disable power management */
 173 static int
 174 apm_enable_disable_pm(int enable)
 175 {
 176         struct apm_softc *sc = &apm_softc;
 177
 178         sc->bios.r.eax = (APM_BIOS << 8) | APM_ENABLEDISABLEPM;
 179
 180         if (sc->intversion >= INTVERSION(1, 1))
 181                 sc->bios.r.ebx  = PMDV_ALLDEV;
 182         else
 183                 sc->bios.r.ebx  = 0xffff;       /* APM version 1.0 only */
 184         sc->bios.r.ecx  = enable;
 185         sc->bios.r.edx = 0;
 186         return (apm_bioscall());
 187 }
 188
 189 /* register driver version (APM 1.1 or later) */
 190 static int
 191 apm_driver_version(int version)
 192 {
 193         struct apm_softc *sc = &apm_softc;
 194
 195         sc->bios.r.eax = (APM_BIOS << 8) | APM_DRVVERSION;
 196         sc->bios.r.ebx  = 0x0;
 197         sc->bios.r.ecx  = version;
 198         sc->bios.r.edx = 0;
 199
 200         if (apm_bioscall() == 0 && sc->bios.r.eax == version)
 201                 return (0);
 202
 203         /* Some old BIOSes don't return the connection version in %ax. */
 204         if (sc->bios.r.eax == ((APM_BIOS << 8) | APM_DRVVERSION))
 205                 return (0);
 206
 207         return (1);
 208 }
 209
 210 /* engage/disengage power management (APM 1.1 or later) */
 211 static int
 212 apm_engage_disengage_pm(int engage)
 213 {
 214         struct apm_softc *sc = &apm_softc;
 215
 216         sc->bios.r.eax = (APM_BIOS << 8) | APM_ENGAGEDISENGAGEPM;
 217         sc->bios.r.ebx = PMDV_ALLDEV;
 218         sc->bios.r.ecx = engage;
 219         sc->bios.r.edx = 0;
 220         return (apm_bioscall());
 221 }
 222
 223 /* get PM event */
 224 static u_int
 225 apm_getevent(void)
 226 {
 227         struct apm_softc *sc = &apm_softc;
 228
 229         sc->bios.r.eax = (APM_BIOS << 8) | APM_GETPMEVENT;
 230
 231         sc->bios.r.ebx = 0;
 232         sc->bios.r.ecx = 0;
 233         sc->bios.r.edx = 0;
 234         if (apm_bioscall())
 235                 return (PMEV_NOEVENT);
 236         return (sc->bios.r.ebx & 0xffff);
 237 }
 238
 239 /* suspend entire system */
 240 static int
 241 apm_suspend_system(int state)
 242 {
 243         struct apm_softc *sc = &apm_softc;
 244
 245         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 246         sc->bios.r.ebx = PMDV_ALLDEV;
 247         sc->bios.r.ecx = state;
 248         sc->bios.r.edx = 0;
 249
 250         if (apm_bioscall()) {
 251                 kprintf("Entire system suspend failure: errcode = %d\n",
 252                        0xff & (sc->bios.r.eax >> 8));
 253                 return 1;
 254         }
 255         return 0;
 256 }
 257
 258 /* Display control */
 259 /*
 260  * Experimental implementation: My laptop machine can't handle this function
 261  * If your laptop can control the display via APM, please inform me.
 262  *                            HOSOKAWA, Tatsumi <hosokawa@jp.FreeBSD.org>
 263  */
 264 int
 265 apm_display(int newstate)
 266 {
 267         struct apm_softc *sc = &apm_softc;
 268
 269         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 270         sc->bios.r.ebx = PMDV_DISP0;
 271         sc->bios.r.ecx = newstate ? PMST_APMENABLED:PMST_SUSPEND;
 272         sc->bios.r.edx = 0;
 273         if (apm_bioscall() == 0) {
 274                 return 0;
 275         }
 276
 277         /* If failed, then try to blank all display devices instead. */
 278         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 279         sc->bios.r.ebx = PMDV_DISPALL;  /* all display devices */
 280         sc->bios.r.ecx = newstate ? PMST_APMENABLED:PMST_SUSPEND;
 281         sc->bios.r.edx = 0;
 282         if (apm_bioscall() == 0) {
 283                 return 0;
 284         }
 285         kprintf("Display off failure: errcode = %d\n",
 286                0xff & (sc->bios.r.eax >> 8));
 287         return 1;
 288 }
 289
 290 /*
 291  * Turn off the entire system.
 292  */
 293 static void
 294 apm_power_off(void *junk, int howto)
 295 {
 296         struct apm_softc *sc = &apm_softc;
 297
 298         /* Not halting powering off, or not active */
 299         if (!(howto & RB_POWEROFF) || !apm_softc.active)
 300                 return;
 301         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 302         sc->bios.r.ebx = PMDV_ALLDEV;
 303         sc->bios.r.ecx = PMST_OFF;
 304         sc->bios.r.edx = 0;
 305         apm_bioscall();
 306 }
 307
 308 /* APM Battery low handler */
 309 static void
 310 apm_battery_low(void)
 311 {
 312         kprintf("\007\007 * * * BATTERY IS LOW * * * \007\007");
 313 }
 314
 315 /* APM hook manager */
 316 static struct apmhook *
 317 apm_add_hook(struct apmhook **list, struct apmhook *ah)
 318 {
 319         struct apmhook *p, *prev;
 320
 321         APM_DPRINT("Add hook \"%s\"\n", ah->ah_name);
 322
 323         crit_enter();
 324         if (ah == NULL)
 325                 panic("illegal apm_hook!");
 326         prev = NULL;
 327         for (p = *list; p != NULL; prev = p, p = p->ah_next)
 328                 if (p->ah_order > ah->ah_order)
 329                         break;
 330
 331         if (prev == NULL) {
 332                 ah->ah_next = *list;
 333                 *list = ah;
 334         } else {
 335                 ah->ah_next = prev->ah_next;
 336                 prev->ah_next = ah;
 337         }
 338         crit_exit();
 339         return ah;
 340 }
 341
 342 static void
 343 apm_del_hook(struct apmhook **list, struct apmhook *ah)
 344 {
 345         struct apmhook *p, *prev;
 346
 347         crit_enter();
 348         prev = NULL;
 349         for (p = *list; p != NULL; prev = p, p = p->ah_next)
 350                 if (p == ah)
 351                         goto deleteit;
 352         panic("Tried to delete unregistered apm_hook.");
 353         goto nosuchnode;
 354 deleteit:
 355         if (prev != NULL)
 356                 prev->ah_next = p->ah_next;
 357         else
 358                 *list = p->ah_next;
 359 nosuchnode:
 360         crit_exit();
 361 }
 362
 363
 364 /* APM driver calls some functions automatically */
 365 static void
 366 apm_execute_hook(struct apmhook *list)
 367 {
 368         struct apmhook *p;
 369
 370         for (p = list; p != NULL; p = p->ah_next) {
 371                 APM_DPRINT("Execute APM hook \"%s.\"\n", p->ah_name);
 372                 if ((*(p->ah_fun))(p->ah_arg))
 373                         kprintf("Warning: APM hook \"%s\" failed", p->ah_name);
 374         }
 375 }
 376
 377
 378 /* establish an apm hook */
 379 struct apmhook *
 380 apm_hook_establish(int apmh, struct apmhook *ah)
 381 {
 382         if (apmh < 0 || apmh >= NAPM_HOOK)
 383                 return NULL;
 384
 385         return apm_add_hook(&hook[apmh], ah);
 386 }
 387
 388 /* disestablish an apm hook */
 389 void
 390 apm_hook_disestablish(int apmh, struct apmhook *ah)
 391 {
 392         if (apmh < 0 || apmh >= NAPM_HOOK)
 393                 return;
 394
 395         apm_del_hook(&hook[apmh], ah);
 396 }
 397
 398
 399 static struct timeval suspend_time;
 400 static struct timeval diff_time;
 401
 402 static int
 403 apm_default_resume(void *arg)
 404 {
 405         u_int second, minute, hour;
 406         struct timeval resume_time, tmp_time;
 407
 408         /* modified for adjkerntz */
 409         crit_enter();
 410         timer_restore();                /* restore the all timers */
 411         inittodr(0);                    /* adjust time to RTC */
 412         microtime(&resume_time);
 413         getmicrotime(&tmp_time);
 414         timevaladd(&tmp_time, &diff_time);
 415
 416 #ifdef FIXME
 417         /* XXX THIS DOESN'T WORK!!! */
 418         time = tmp_time;
 419 #endif
 420
 421 #ifdef APM_FIXUP_CALLTODO
 422         /* Calculate the delta time suspended */
 423         timevalsub(&resume_time, &suspend_time);
 424         /* Fixup the calltodo list with the delta time. */
 425         adjust_timeout_calltodo(&resume_time);
 426 #endif /* APM_FIXUP_CALLTODOK */
 427         crit_exit();
 428 #ifndef APM_FIXUP_CALLTODO
 429         second = resume_time.tv_sec - suspend_time.tv_sec;
 430 #else /* APM_FIXUP_CALLTODO */
 431         /*
 432          * We've already calculated resume_time to be the delta between
 433          * the suspend and the resume.
 434          */
 435         second = resume_time.tv_sec;
 436 #endif /* APM_FIXUP_CALLTODO */
 437         hour = second / 3600;
 438         second %= 3600;
 439         minute = second / 60;
 440         second %= 60;
 441         log(LOG_NOTICE, "resumed from suspended mode (slept %02d:%02d:%02d)\n",
 442                 hour, minute, second);
 443         return 0;
 444 }
 445
 446 static int
 447 apm_default_suspend(void *arg)
 448 {
 449         crit_enter();
 450         microtime(&diff_time);
 451         inittodr(0);
 452         microtime(&suspend_time);
 453         timevalsub(&diff_time, &suspend_time);
 454         crit_exit();
 455         return 0;
 456 }
 457
 458 static int apm_record_event (struct apm_softc *, u_int);
 459 static void apm_processevent(void);
 460
 461 static u_int apm_op_inprog = 0;
 462
 463 static void
 464 apm_do_suspend(void)
 465 {
 466         struct apm_softc *sc = &apm_softc;
 467         int error;
 468
 469         if (!sc)
 470                 return;
 471
 472         apm_op_inprog = 0;
 473         sc->suspends = sc->suspend_countdown = 0;
 474
 475         if (sc->initialized) {
 476                 error = DEVICE_SUSPEND(root_bus);
 477                 if (error) {
 478                         DEVICE_RESUME(root_bus);
 479                 } else {
 480                         apm_execute_hook(hook[APM_HOOK_SUSPEND]);
 481                         if (apm_suspend_system(PMST_SUSPEND) == 0) {
 482                                 apm_processevent();
 483                         } else {
 484                                 /* Failure, 'resume' the system again */
 485                                 apm_execute_hook(hook[APM_HOOK_RESUME]);
 486                                 DEVICE_RESUME(root_bus);
 487                         }
 488                 }
 489         }
 490 }
 491
 492 static void
 493 apm_do_standby(void)
 494 {
 495         struct apm_softc *sc = &apm_softc;
 496
 497         if (!sc)
 498                 return;
 499
 500         apm_op_inprog = 0;
 501         sc->standbys = sc->standby_countdown = 0;
 502
 503         if (sc->initialized) {
 504                 /*
 505                  * As far as standby, we don't need to execute
 506                  * all of suspend hooks.
 507                  */
 508                 apm_default_suspend(&apm_softc);
 509                 if (apm_suspend_system(PMST_STANDBY) == 0)
 510                         apm_processevent();
 511         }
 512 }
 513
 514 static void
 515 apm_lastreq_notify(void)
 516 {
 517         struct apm_softc *sc = &apm_softc;
 518
 519         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 520         sc->bios.r.ebx = PMDV_ALLDEV;
 521         sc->bios.r.ecx = PMST_LASTREQNOTIFY;
 522         sc->bios.r.edx = 0;
 523         apm_bioscall();
 524 }
 525
 526 static int
 527 apm_lastreq_rejected(void)
 528 {
 529         struct apm_softc *sc = &apm_softc;
 530
 531         if (apm_op_inprog == 0) {
 532                 return 1;       /* no operation in progress */
 533         }
 534
 535         sc->bios.r.eax = (APM_BIOS << 8) | APM_SETPWSTATE;
 536         sc->bios.r.ebx = PMDV_ALLDEV;
 537         sc->bios.r.ecx = PMST_LASTREQREJECT;
 538         sc->bios.r.edx = 0;
 539
 540         if (apm_bioscall()) {
 541                 APM_DPRINT("apm_lastreq_rejected: failed\n");
 542                 return 1;
 543         }
 544         apm_op_inprog = 0;
 545         return 0;
 546 }
 547
 548 /*
 549  * Public interface to the suspend/resume:
 550  *
 551  * Execute suspend and resume hook before and after sleep, respectively.
 552  *
 553  */
 554
 555 void
 556 apm_suspend(int state)
 557 {
 558         struct apm_softc *sc = &apm_softc;
 559
 560         if (!sc->initialized)
 561                 return;
 562
 563         switch (state) {
 564         case PMST_SUSPEND:
 565                 if (sc->suspends)
 566                         return;
 567                 sc->suspends++;
 568                 sc->suspend_countdown = apm_suspend_delay;
 569                 break;
 570         case PMST_STANDBY:
 571                 if (sc->standbys)
 572                         return;
 573                 sc->standbys++;
 574                 sc->standby_countdown = apm_standby_delay;
 575                 break;
 576         default:
 577                 kprintf("apm_suspend: Unknown Suspend state 0x%x\n", state);
 578                 return;
 579         }
 580
 581         apm_op_inprog++;
 582         apm_lastreq_notify();
 583 }
 584
 585 void
 586 apm_resume(void)
 587 {
 588         struct apm_softc *sc = &apm_softc;
 589
 590         if (!sc)
 591                 return;
 592
 593         if (sc->initialized) {
 594                 apm_execute_hook(hook[APM_HOOK_RESUME]);
 595                 DEVICE_RESUME(root_bus);
 596         }
 597 }
 598
 599
 600 /* get power status per battery */
 601 static int
 602 apm_get_pwstatus(apm_pwstatus_t app)
 603 {
 604         struct apm_softc *sc = &apm_softc;
 605
 606         if (app->ap_device != PMDV_ALLDEV &&
 607             (app->ap_device < PMDV_BATT0 || app->ap_device > PMDV_BATT_ALL))
 608                 return 1;
 609
 610         sc->bios.r.eax = (APM_BIOS << 8) | APM_GETPWSTATUS;
 611         sc->bios.r.ebx = app->ap_device;
 612         sc->bios.r.ecx = 0;
 613         sc->bios.r.edx = 0xffff;        /* default to unknown battery time */
 614
 615         if (apm_bioscall())
 616                 return 1;
 617
 618         app->ap_acline    = (sc->bios.r.ebx >> 8) & 0xff;
 619         app->ap_batt_stat = sc->bios.r.ebx & 0xff;
 620         app->ap_batt_flag = (sc->bios.r.ecx >> 8) & 0xff;
 621         app->ap_batt_life = sc->bios.r.ecx & 0xff;
 622         sc->bios.r.edx &= 0xffff;
 623         if (sc->bios.r.edx == 0xffff)   /* Time is unknown */
 624                 app->ap_batt_time = -1;
 625         else if (sc->bios.r.edx & 0x8000)       /* Time is in minutes */
 626                 app->ap_batt_time = (sc->bios.r.edx & 0x7fff) * 60;
 627         else                            /* Time is in seconds */
 628                 app->ap_batt_time = sc->bios.r.edx;
 629
 630         return 0;
 631 }
 632
 633
 634 /* get APM information */
 635 static int
 636 apm_get_info(apm_info_t aip)
 637 {
 638         struct apm_softc *sc = &apm_softc;
 639         struct apm_pwstatus aps;
 640
 641         bzero(&aps, sizeof(aps));
 642         aps.ap_device = PMDV_ALLDEV;
 643         if (apm_get_pwstatus(&aps))
 644                 return 1;
 645
 646         aip->ai_infoversion = 1;
 647         aip->ai_acline      = aps.ap_acline;
 648         aip->ai_batt_stat   = aps.ap_batt_stat;
 649         aip->ai_batt_life   = aps.ap_batt_life;
 650         aip->ai_batt_time   = aps.ap_batt_time;
 651         aip->ai_major       = (u_int)sc->majorversion;
 652         aip->ai_minor       = (u_int)sc->minorversion;
 653         aip->ai_status      = (u_int)sc->active;
 654
 655         sc->bios.r.eax = (APM_BIOS << 8) | APM_GETCAPABILITIES;
 656         sc->bios.r.ebx = 0;
 657         sc->bios.r.ecx = 0;
 658         sc->bios.r.edx = 0;
 659         if (apm_bioscall()) {
 660                 aip->ai_batteries = -1; /* Unknown */
 661                 aip->ai_capabilities = 0xff00; /* Unknown, with no bits set */
 662         } else {
 663                 aip->ai_batteries = sc->bios.r.ebx & 0xff;
 664                 aip->ai_capabilities = sc->bios.r.ecx & 0xf;
 665         }
 666
 667         bzero(aip->ai_spare, sizeof aip->ai_spare);
 668
 669         return 0;
 670 }
 671
 672
 673 /* inform APM BIOS that CPU is idle */
 674 void
 675 apm_cpu_idle(void)
 676 {
 677         struct apm_softc *sc = &apm_softc;
 678
 679         if (sc->active) {
 680
 681                 sc->bios.r.eax = (APM_BIOS <<8) | APM_CPUIDLE;
 682                 sc->bios.r.edx = sc->bios.r.ecx = sc->bios.r.ebx = 0;
 683                 apm_bioscall();
 684         }
 685         /*
 686          * Some APM implementation halts CPU in BIOS, whenever
 687          * "CPU-idle" function are invoked, but swtch() of
 688          * FreeBSD halts CPU, therefore, CPU is halted twice
 689          * in the sched loop. It makes the interrupt latency
 690          * terribly long and be able to cause a serious problem
 691          * in interrupt processing. We prevent it by removing
 692          * "hlt" operation from swtch() and managed it under
 693          * APM driver.
 694          */
 695         if (!sc->active || sc->always_halt_cpu)
 696                 __asm("hlt");   /* wait for interrupt */
 697 }
 698
 699 /* inform APM BIOS that CPU is busy */
 700 void
 701 apm_cpu_busy(void)
 702 {
 703         struct apm_softc *sc = &apm_softc;
 704
 705         /*
 706          * The APM specification says this is only necessary if your BIOS
 707          * slows down the processor in the idle task, otherwise it's not
 708          * necessary.
 709          */
 710         if (sc->slow_idle_cpu && sc->active) {
 711
 712                 sc->bios.r.eax = (APM_BIOS <<8) | APM_CPUBUSY;
 713                 sc->bios.r.edx = sc->bios.r.ecx = sc->bios.r.ebx = 0;
 714                 apm_bioscall();
 715         }
 716 }
 717
 718
 719 /*
 720  * APM timeout routine:
 721  *
 722  * This routine is automatically called by timer once per second.
 723  */
 724
 725 static void
 726 apm_timeout(void *dummy)
 727 {
 728         struct apm_softc *sc = &apm_softc;
 729
 730         if (apm_op_inprog)
 731                 apm_lastreq_notify();
 732
 733         if (sc->standbys && sc->standby_countdown-- <= 0)
 734                 apm_do_standby();
 735
 736         if (sc->suspends && sc->suspend_countdown-- <= 0)
 737                 apm_do_suspend();
 738
 739         if (!sc->bios_busy)
 740                 apm_processevent();
 741
 742         if (sc->active == 1) {
 743                 /* Run slightly more oftan than 1 Hz */
 744                 callout_reset(&apm_timeout_ch, hz - 1, apm_timeout, NULL);
 745         }
 746 }
 747
 748 /* enable APM BIOS */
 749 static void
 750 apm_event_enable(void)
 751 {
 752         struct apm_softc *sc = &apm_softc;
 753
 754         APM_DPRINT("called apm_event_enable()\n");
 755         if (sc->initialized) {
 756                 sc->active = 1;
 757                 callout_init(&apm_timeout_ch);
 758                 apm_timeout(sc);
 759         }
 760 }
 761
 762 /* disable APM BIOS */
 763 static void
 764 apm_event_disable(void)
 765 {
 766         struct apm_softc *sc = &apm_softc;
 767
 768         APM_DPRINT("called apm_event_disable()\n");
 769         if (sc->initialized) {
 770                 callout_stop(&apm_timeout_ch);
 771                 sc->active = 0;
 772         }
 773 }
 774
 775 /* halt CPU in scheduling loop */
 776 static void
 777 apm_halt_cpu(void)
 778 {
 779         struct apm_softc *sc = &apm_softc;
 780
 781         if (sc->initialized)
 782                 sc->always_halt_cpu = 1;
 783 }
 784
 785 /* don't halt CPU in scheduling loop */
 786 static void
 787 apm_not_halt_cpu(void)
 788 {
 789         struct apm_softc *sc = &apm_softc;
 790
 791         if (sc->initialized)
 792                 sc->always_halt_cpu = 0;
 793 }
 794
 795 /* device driver definitions */
 796
 797 /*
 798  * probe for APM BIOS
 799  */
 800 static int
 801 apm_probe(device_t dev)
 802 {
 803 #define APM_KERNBASE    KERNBASE
 804         struct vm86frame        vmf;
 805         struct apm_softc        *sc = &apm_softc;
 806         int                     disabled, flags;
 807
 808         if (resource_int_value("apm", 0, "disabled", &disabled) == 0
 809             && disabled != 0)
 810                 return ENXIO;
 811
 812         device_set_desc(dev, "APM BIOS");
 813
 814         if ( device_get_unit(dev) > 0 ) {
 815                 kprintf("apm: Only one APM driver supported.\n");
 816                 return ENXIO;
 817         }
 818
 819         if (resource_int_value("apm", 0, "flags", &flags) != 0)
 820                 flags = 0;
 821
 822         bzero(&vmf, sizeof(struct vm86frame));          /* safety */
 823         bzero(&apm_softc, sizeof(apm_softc));
 824         vmf.vmf_ah = APM_BIOS;
 825         vmf.vmf_al = APM_INSTCHECK;
 826         vmf.vmf_bx = 0;
 827         if (vm86_intcall(APM_INT, &vmf))
 828                 return ENXIO;                   /* APM not found */
 829         if (vmf.vmf_bx != 0x504d) {
 830                 kprintf("apm: incorrect signature (0x%x)\n", vmf.vmf_bx);
 831                 return ENXIO;
 832         }
 833         if ((vmf.vmf_cx & (APM_32BIT_SUPPORT | APM_16BIT_SUPPORT)) == 0) {
 834                 kprintf("apm: protected mode connections are not supported\n");
 835                 return ENXIO;
 836         }
 837
 838         apm_version = vmf.vmf_ax;
 839         sc->slow_idle_cpu = ((vmf.vmf_cx & APM_CPUIDLE_SLOW) != 0);
 840         sc->disabled = ((vmf.vmf_cx & APM_DISABLED) != 0);
 841         sc->disengaged = ((vmf.vmf_cx & APM_DISENGAGED) != 0);
 842
 843         vmf.vmf_ah = APM_BIOS;
 844         vmf.vmf_al = APM_DISCONNECT;
 845         vmf.vmf_bx = 0;
 846         vm86_intcall(APM_INT, &vmf);            /* disconnect, just in case */
 847
 848         if ((vmf.vmf_cx & APM_32BIT_SUPPORT) != 0) {
 849                 vmf.vmf_ah = APM_BIOS;
 850                 vmf.vmf_al = APM_PROT32CONNECT;
 851                 vmf.vmf_bx = 0;
 852                 if (vm86_intcall(APM_INT, &vmf)) {
 853                         kprintf("apm: 32-bit connection error.\n");
 854                         return (ENXIO);
 855                 }
 856                 sc->bios.seg.code32.base = (vmf.vmf_ax << 4) + APM_KERNBASE;
 857                 sc->bios.seg.code32.limit = 0xffff;
 858                 sc->bios.seg.code16.base = (vmf.vmf_cx << 4) + APM_KERNBASE;
 859                 sc->bios.seg.code16.limit = 0xffff;
 860                 sc->bios.seg.data.base = (vmf.vmf_dx << 4) + APM_KERNBASE;
 861                 sc->bios.seg.data.limit = 0xffff;
 862                 sc->bios.entry = vmf.vmf_ebx;
 863                 sc->connectmode = APM_PROT32CONNECT;
 864         } else {
 865                 /* use 16-bit connection */
 866                 vmf.vmf_ah = APM_BIOS;
 867                 vmf.vmf_al = APM_PROT16CONNECT;
 868                 vmf.vmf_bx = 0;
 869                 if (vm86_intcall(APM_INT, &vmf)) {
 870                         kprintf("apm: 16-bit connection error.\n");
 871                         return (ENXIO);
 872                 }
 873                 sc->bios.seg.code16.base = (vmf.vmf_ax << 4) + APM_KERNBASE;
 874                 sc->bios.seg.code16.limit = 0xffff;
 875                 sc->bios.seg.data.base = (vmf.vmf_cx << 4) + APM_KERNBASE;
 876                 sc->bios.seg.data.limit = 0xffff;
 877                 sc->bios.entry = vmf.vmf_bx;
 878                 sc->connectmode = APM_PROT16CONNECT;
 879         }
 880         return(0);
 881 }
 882
 883
 884 /*
 885  * return 0 if the user will notice and handle the event,
 886  * return 1 if the kernel driver should do so.
 887  */
 888 static int
 889 apm_record_event(struct apm_softc *sc, u_int event_type)
 890 {
 891         struct apm_event_info *evp;
 892
 893         if ((sc->sc_flags & SCFLAG_OPEN) == 0)
 894                 return 1;               /* no user waiting */
 895         if (sc->event_count == APM_NEVENTS)
 896                 return 1;                       /* overflow */
 897         if (sc->event_filter[event_type] == 0)
 898                 return 1;               /* not registered */
 899         evp = &sc->event_list[sc->event_ptr];
 900         sc->event_count++;
 901         sc->event_ptr++;
 902         sc->event_ptr %= APM_NEVENTS;
 903         evp->type = event_type;
 904         evp->index = ++apm_evindex;
 905         KNOTE(&sc->sc_rkq.ki_note, 0);
 906         return (sc->sc_flags & SCFLAG_OCTL) ? 0 : 1; /* user may handle */
 907 }
 908
 909 /* Process APM event */
 910 static void
 911 apm_processevent(void)
 912 {
 913         int apm_event;
 914         struct apm_softc *sc = &apm_softc;
 915
 916 #define OPMEV_DEBUGMESSAGE(symbol) case symbol:                         \
 917         APM_DPRINT("Received APM Event: " #symbol "\n");
 918
 919         do {
 920                 apm_event = apm_getevent();
 921                 switch (apm_event) {
 922                     OPMEV_DEBUGMESSAGE(PMEV_STANDBYREQ);
 923                         if (apm_op_inprog == 0) {
 924                             apm_op_inprog++;
 925                             if (apm_record_event(sc, apm_event)) {
 926                                 apm_suspend(PMST_STANDBY);
 927                             }
 928                         }
 929                         break;
 930                     OPMEV_DEBUGMESSAGE(PMEV_USERSTANDBYREQ);
 931                         if (apm_op_inprog == 0) {
 932                             apm_op_inprog++;
 933                             if (apm_record_event(sc, apm_event)) {
 934                                 apm_suspend(PMST_STANDBY);
 935                             }
 936                         }
 937                         break;
 938                     OPMEV_DEBUGMESSAGE(PMEV_SUSPENDREQ);
 939                         apm_lastreq_notify();
 940                         if (apm_op_inprog == 0) {
 941                             apm_op_inprog++;
 942                             if (apm_record_event(sc, apm_event)) {
 943                                 apm_do_suspend();
 944                             }
 945                         }
 946                         return; /* XXX skip the rest */
 947                     OPMEV_DEBUGMESSAGE(PMEV_USERSUSPENDREQ);
 948                         apm_lastreq_notify();
 949                         if (apm_op_inprog == 0) {
 950                             apm_op_inprog++;
 951                             if (apm_record_event(sc, apm_event)) {
 952                                 apm_do_suspend();
 953                             }
 954                         }
 955                         return; /* XXX skip the rest */
 956                     OPMEV_DEBUGMESSAGE(PMEV_CRITSUSPEND);
 957                         apm_do_suspend();
 958                         break;
 959                     OPMEV_DEBUGMESSAGE(PMEV_NORMRESUME);
 960                         apm_record_event(sc, apm_event);
 961                         apm_resume();
 962                         break;
 963                     OPMEV_DEBUGMESSAGE(PMEV_CRITRESUME);
 964                         apm_record_event(sc, apm_event);
 965                         apm_resume();
 966                         break;
 967                     OPMEV_DEBUGMESSAGE(PMEV_STANDBYRESUME);
 968                         apm_record_event(sc, apm_event);
 969                         apm_resume();
 970                         break;
 971                     OPMEV_DEBUGMESSAGE(PMEV_BATTERYLOW);
 972                         if (apm_record_event(sc, apm_event)) {
 973                             apm_battery_low();
 974                             apm_suspend(PMST_SUSPEND);
 975                         }
 976                         break;
 977                     OPMEV_DEBUGMESSAGE(PMEV_POWERSTATECHANGE);
 978                         apm_record_event(sc, apm_event);
 979                         break;
 980                     OPMEV_DEBUGMESSAGE(PMEV_UPDATETIME);
 981                         apm_record_event(sc, apm_event);
 982                         inittodr(0);    /* adjust time to RTC */
 983                         break;
 984                     OPMEV_DEBUGMESSAGE(PMEV_CAPABILITIESCHANGE);
 985                         apm_record_event(sc, apm_event);
 986                         break;
 987                     case PMEV_NOEVENT:
 988                         break;
 989                     default:
 990                         kprintf("Unknown Original APM Event 0x%x\n", apm_event);
 991                             break;
 992                 }
 993         } while (apm_event != PMEV_NOEVENT);
 994 }
 995
 996 /*
 997  * Attach APM:
 998  *
 999  * Initialize APM driver
1000  */
1001
1002 static int
1003 apm_attach(device_t dev)
1004 {
1005         struct apm_softc        *sc = &apm_softc;
1006         int                     flags;
1007         int                     drv_version;
1008
1009         if (resource_int_value("apm", 0, "flags", &flags) != 0)
1010                 flags = 0;
1011
1012         sc->initialized = 0;
1013
1014         /* Must be externally enabled */
1015         sc->active = 0;
1016
1017         /* Always call HLT in idle loop */
1018         sc->always_halt_cpu = 1;
1019
1020         kgetenv_int("debug.apm_debug", &apm_debug);
1021
1022         /* print bootstrap messages */
1023         APM_DPRINT("apm: APM BIOS version %04lx\n",  apm_version);
1024         APM_DPRINT("apm: Code16 0x%08x, Data 0x%08x\n",
1025             sc->bios.seg.code16.base, sc->bios.seg.data.base);
1026         APM_DPRINT("apm: Code entry 0x%08x, Idling CPU %s, Management %s\n",
1027             sc->bios.entry, is_enabled(sc->slow_idle_cpu),
1028             is_enabled(!sc->disabled));
1029         APM_DPRINT("apm: CS_limit=0x%x, DS_limit=0x%x\n",
1030             sc->bios.seg.code16.limit, sc->bios.seg.data.limit);
1031
1032         /*
1033          * In one test, apm bios version was 1.02; an attempt to register
1034          * a 1.04 driver resulted in a 1.00 connection!  Registering a
1035          * 1.02 driver resulted in a 1.02 connection.
1036          */
1037         drv_version = apm_version > 0x102 ? 0x102 : apm_version;
1038         for (; drv_version > 0x100; drv_version--)
1039                 if (apm_driver_version(drv_version) == 0)
1040                         break;
1041         sc->minorversion = ((drv_version & 0x00f0) >>  4) * 10 +
1042                 ((drv_version & 0x000f) >> 0);
1043         sc->majorversion = ((drv_version & 0xf000) >> 12) * 10 +
1044                 ((apm_version & 0x0f00) >> 8);
1045
1046         sc->intversion = INTVERSION(sc->majorversion, sc->minorversion);
1047
1048         if (sc->intversion >= INTVERSION(1, 1))
1049                 APM_DPRINT("apm: Engaged control %s\n", is_enabled(!sc->disengaged));
1050         device_printf(dev, "found APM BIOS v%ld.%ld, connected at v%d.%d\n",
1051                ((apm_version & 0xf000) >> 12) * 10 + ((apm_version & 0x0f00) >> 8),
1052                ((apm_version & 0x00f0) >> 4) * 10 + ((apm_version & 0x000f) >> 0),
1053                sc->majorversion, sc->minorversion);
1054
1055
1056         APM_DPRINT("apm: Slow Idling CPU %s\n", is_enabled(sc->slow_idle_cpu));
1057         /* enable power management */
1058         if (sc->disabled) {
1059                 if (apm_enable_disable_pm(1)) {
1060                         APM_DPRINT("apm: *Warning* enable function failed! [%x]\n",
1061                             (sc->bios.r.eax >> 8) & 0xff);
1062                 }
1063         }
1064
1065         /* engage power managment (APM 1.1 or later) */
1066         if (sc->intversion >= INTVERSION(1, 1) && sc->disengaged) {
1067                 if (apm_engage_disengage_pm(1)) {
1068                         APM_DPRINT("apm: *Warning* engage function failed err=[%x]",
1069                             (sc->bios.r.eax >> 8) & 0xff);
1070                         APM_DPRINT(" (Docked or using external power?).\n");
1071                 }
1072         }
1073
1074         /* default suspend hook */
1075         sc->sc_suspend.ah_fun = apm_default_suspend;
1076         sc->sc_suspend.ah_arg = sc;
1077         sc->sc_suspend.ah_name = "default suspend";
1078         sc->sc_suspend.ah_order = APM_MAX_ORDER;
1079
1080         /* default resume hook */
1081         sc->sc_resume.ah_fun = apm_default_resume;
1082         sc->sc_resume.ah_arg = sc;
1083         sc->sc_resume.ah_name = "default resume";
1084         sc->sc_resume.ah_order = APM_MIN_ORDER;
1085
1086         apm_hook_establish(APM_HOOK_SUSPEND, &sc->sc_suspend);
1087         apm_hook_establish(APM_HOOK_RESUME , &sc->sc_resume);
1088
1089         /* Power the system off using APM */
1090         EVENTHANDLER_REGISTER(shutdown_final, apm_power_off, NULL,
1091                               SHUTDOWN_PRI_LAST);
1092
1093         sc->initialized = 1;
1094
1095         make_dev(&apm_ops, 0, UID_ROOT, GID_OPERATOR, 0660, "apm");
1096         make_dev(&apm_ops, 8, UID_ROOT, GID_OPERATOR, 0660, "apmctl");
1097         return 0;
1098 }
1099
1100 static int
1101 apmopen(struct dev_open_args *ap)
1102 {
1103         cdev_t dev = ap->a_head.a_dev;
1104         struct apm_softc *sc = &apm_softc;
1105         int ctl = APMDEV(dev);
1106
1107         if (!sc->initialized)
1108                 return (ENXIO);
1109
1110         switch (ctl) {
1111         case APMDEV_CTL:
1112                 if (!(ap->a_oflags & FWRITE))
1113                         return EINVAL;
1114                 if (sc->sc_flags & SCFLAG_OCTL)
1115                         return EBUSY;
1116                 sc->sc_flags |= SCFLAG_OCTL;
1117                 bzero(sc->event_filter, sizeof sc->event_filter);
1118                 break;
1119         case APMDEV_NORMAL:
1120                 sc->sc_flags |= SCFLAG_ONORMAL;
1121                 break;
1122         default:
1123                 return ENXIO;
1124                 break;
1125         }
1126         return 0;
1127 }
1128
1129 static int
1130 apmclose(struct dev_close_args *ap)
1131 {
1132         cdev_t dev = ap->a_head.a_dev;
1133         struct apm_softc *sc = &apm_softc;
1134         int ctl = APMDEV(dev);
1135
1136         switch (ctl) {
1137         case APMDEV_CTL:
1138                 apm_lastreq_rejected();
1139                 sc->sc_flags &= ~SCFLAG_OCTL;
1140                 bzero(sc->event_filter, sizeof sc->event_filter);
1141                 break;
1142         case APMDEV_NORMAL:
1143                 sc->sc_flags &= ~SCFLAG_ONORMAL;
1144                 break;
1145         }
1146         if ((sc->sc_flags & SCFLAG_OPEN) == 0) {
1147                 sc->event_count = 0;
1148                 sc->event_ptr = 0;
1149         }
1150         return 0;
1151 }
1152
1153 static int
1154 apmioctl(struct dev_ioctl_args *ap)
1155 {
1156         cdev_t dev = ap->a_head.a_dev;
1157         struct apm_softc *sc = &apm_softc;
1158         struct apm_bios_arg *args;
1159         int error = 0;
1160         int ret;
1161         int newstate;
1162
1163         if (!sc->initialized)
1164                 return (ENXIO);
1165         APM_DPRINT("APM ioctl: cmd = 0x%lx\n", ap->a_cmd);
1166
1167         switch (ap->a_cmd) {
1168         case APMIO_SUSPEND:
1169                 if (!(ap->a_fflag & FWRITE))
1170                         return (EPERM);
1171                 if (sc->active)
1172                         apm_suspend(PMST_SUSPEND);
1173                 else
1174                         error = EINVAL;
1175                 break;
1176
1177         case APMIO_STANDBY:
1178                 if (!(ap->a_fflag & FWRITE))
1179                         return (EPERM);
1180                 if (sc->active)
1181                         apm_suspend(PMST_STANDBY);
1182                 else
1183                         error = EINVAL;
1184                 break;
1185
1186         case APMIO_GETINFO_OLD:
1187                 {
1188                         struct apm_info info;
1189                         apm_info_old_t aiop;
1190
1191                         if (apm_get_info(&info))
1192                                 error = ENXIO;
1193                         aiop = (apm_info_old_t)ap->a_data;
1194                         aiop->ai_major = info.ai_major;
1195                         aiop->ai_minor = info.ai_minor;
1196                         aiop->ai_acline = info.ai_acline;
1197                         aiop->ai_batt_stat = info.ai_batt_stat;
1198                         aiop->ai_batt_life = info.ai_batt_life;
1199                         aiop->ai_status = info.ai_status;
1200                 }
1201                 break;
1202         case APMIO_GETINFO:
1203                 if (apm_get_info((apm_info_t)ap->a_data))
1204                         error = ENXIO;
1205                 break;
1206         case APMIO_GETPWSTATUS:
1207                 if (apm_get_pwstatus((apm_pwstatus_t)ap->a_data))
1208                         error = ENXIO;
1209                 break;
1210         case APMIO_ENABLE:
1211                 if (!(ap->a_fflag & FWRITE))
1212                         return (EPERM);
1213                 apm_event_enable();
1214                 break;
1215         case APMIO_DISABLE:
1216                 if (!(ap->a_fflag & FWRITE))
1217                         return (EPERM);
1218                 apm_event_disable();
1219                 break;
1220         case APMIO_HALTCPU:
1221                 if (!(ap->a_fflag & FWRITE))
1222                         return (EPERM);
1223                 apm_halt_cpu();
1224                 break;
1225         case APMIO_NOTHALTCPU:
1226                 if (!(ap->a_fflag & FWRITE))
1227                         return (EPERM);
1228                 apm_not_halt_cpu();
1229                 break;
1230         case APMIO_DISPLAY:
1231                 if (!(ap->a_fflag & FWRITE))
1232                         return (EPERM);
1233                 newstate = *(int *)ap->a_data;
1234                 if (apm_display(newstate))
1235                         error = ENXIO;
1236                 break;
1237         case APMIO_BIOS:
1238                 if (!(ap->a_fflag & FWRITE))
1239                         return (EPERM);
1240                 /* XXX compatibility with the old interface */
1241                 args = (struct apm_bios_arg *)ap->a_data;
1242                 sc->bios.r.eax = args->eax;
1243                 sc->bios.r.ebx = args->ebx;
1244                 sc->bios.r.ecx = args->ecx;
1245                 sc->bios.r.edx = args->edx;
1246                 sc->bios.r.esi = args->esi;
1247                 sc->bios.r.edi = args->edi;
1248                 if ((ret = apm_bioscall())) {
1249                         /*
1250                          * Return code 1 means bios call was unsuccessful.
1251                          * Error code is stored in %ah.
1252                          * Return code -1 means bios call was unsupported
1253                          * in the APM BIOS version.
1254                          */
1255                         if (ret == -1) {
1256                                 error = EINVAL;
1257                         }
1258                 } else {
1259                         /*
1260                          * Return code 0 means bios call was successful.
1261                          * We need only %al and can discard %ah.
1262                          */
1263                         sc->bios.r.eax &= 0xff;
1264                 }
1265                 args->eax = sc->bios.r.eax;
1266                 args->ebx = sc->bios.r.ebx;
1267                 args->ecx = sc->bios.r.ecx;
1268                 args->edx = sc->bios.r.edx;
1269                 args->esi = sc->bios.r.esi;
1270                 args->edi = sc->bios.r.edi;
1271                 break;
1272         default:
1273                 error = EINVAL;
1274                 break;
1275         }
1276
1277         /* for /dev/apmctl */
1278         if (APMDEV(dev) == APMDEV_CTL) {
1279                 struct apm_event_info *evp;
1280                 int i;
1281
1282                 error = 0;
1283                 switch (ap->a_cmd) {
1284                 case APMIO_NEXTEVENT:
1285                         if (!sc->event_count) {
1286                                 error = EAGAIN;
1287                         } else {
1288                                 evp = (struct apm_event_info *)ap->a_data;
1289                                 i = sc->event_ptr + APM_NEVENTS - sc->event_count;
1290                                 i %= APM_NEVENTS;
1291                                 *evp = sc->event_list[i];
1292                                 sc->event_count--;
1293                         }
1294                         break;
1295                 case APMIO_REJECTLASTREQ:
1296                         if (apm_lastreq_rejected()) {
1297                                 error = EINVAL;
1298                         }
1299                         break;
1300                 default:
1301                         error = EINVAL;
1302                         break;
1303                 }
1304         }
1305
1306         return error;
1307 }
1308
1309 static int
1310 apmwrite(struct dev_write_args *ap)
1311 {
1312         cdev_t dev = ap->a_head.a_dev;
1313         struct uio *uio = ap->a_uio;
1314         struct apm_softc *sc = &apm_softc;
1315         u_int event_type;
1316         int error;
1317         u_char enabled;
1318
1319         if (APMDEV(dev) != APMDEV_CTL)
1320                 return(ENODEV);
1321         if (uio->uio_resid != sizeof(u_int))
1322                 return(E2BIG);
1323
1324         if ((error = uiomove((caddr_t)&event_type, sizeof(u_int), uio)))
1325                 return(error);
1326
1327         if (event_type < 0 || event_type >= APM_NPMEV)
1328                 return(EINVAL);
1329
1330         if (sc->event_filter[event_type] == 0) {
1331                 enabled = 1;
1332         } else {
1333                 enabled = 0;
1334         }
1335         sc->event_filter[event_type] = enabled;
1336         APM_DPRINT("apmwrite: event 0x%x %s\n", event_type, is_enabled(enabled));
1337
1338         return uio->uio_resid;
1339 }
1340
1341 static struct filterops apmfiltops_read =
1342         { FILTEROP_ISFD, NULL, apmfilter_detach, apmfilter_read };
1343 static struct filterops apmfiltops_write =
1344         { FILTEROP_ISFD, NULL, apmfilter_detach, apmfilter_write };
1345
1346 static int
1347 apmkqfilter(struct dev_kqfilter_args *ap)
1348 {
1349         struct apm_softc *sc = &apm_softc;
1350         struct knote *kn = ap->a_kn;
1351         struct klist *klist;
1352
1353         ap->a_result = 0;
1354
1355         switch (kn->kn_filter) {
1356         case EVFILT_READ:
1357                 kn->kn_fop = &apmfiltops_read;
1358                 kn->kn_hook = (caddr_t)sc;
1359                 break;
1360         case EVFILT_WRITE:
1361                 kn->kn_fop = &apmfiltops_write;
1362                 kn->kn_hook = (caddr_t)sc;
1363                 break;
1364         default:
1365                 ap->a_result = EOPNOTSUPP;
1366                 return (0);
1367         }
1368
1369         klist = &sc->sc_rkq.ki_note;
1370         knote_insert(klist, kn);
1371
1372         return (0);
1373 }
1374
1375 static void
1376 apmfilter_detach(struct knote *kn)
1377 {
1378         struct apm_softc *sc = (struct apm_softc *)kn->kn_hook;
1379         struct klist *klist;
1380
1381         klist = &sc->sc_rkq.ki_note;
1382         knote_remove(klist, kn);
1383 }
1384
1385 static int
1386 apmfilter_read(struct knote *kn, long hint)
1387 {
1388         struct apm_softc *sc = (struct apm_softc *)kn->kn_hook;
1389         int ready = 0;
1390
1391         if (sc->event_count)
1392                 ready = 1;
1393
1394         return (ready);
1395 }
1396
1397 static int
1398 apmfilter_write(struct knote *kn, long hint)
1399 {
1400         /* write()'s are always OK */
1401         return (1);
1402 }
1403
1404 /*
1405  * Because apm is a static device that always exists under any attached
1406  * isa device, and not scanned by the isa device, we need an identify
1407  * function to install the device so we can probe for it.
1408  */
1409 static device_method_t apm_methods[] = {
1410         /* Device interface */
1411         DEVMETHOD(device_identify,      bus_generic_identify),
1412         DEVMETHOD(device_probe,         apm_probe),
1413         DEVMETHOD(device_attach,        apm_attach),
1414
1415         { 0, 0 }
1416 };
1417
1418 static driver_t apm_driver = {
1419         "apm",
1420         apm_methods,
1421         1,                      /* no softc (XXX) */
1422 };
1423
1424 static devclass_t apm_devclass;
1425
1426 DRIVER_MODULE(apm, nexus, apm_driver, apm_devclass, NULL, NULL);
1427