/*-
 * Copyright (c) 2002-2003 Taku YAMAMOTO <taku@cent.saitama-u.ac.jp>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: head/sys/dev/acpica/acpi_video.c 258780 2013-11-30 22:17:27Z eadler $
 *      $Id: acpi_vid.c,v 1.4 2003/10/13 10:07:36 taku Exp $
 */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/power.h>
#include <sys/queue.h>
#include <sys/sysctl.h>

#include "acpi.h"
#include "acpivar.h"

/* ACPI video extension driver. */
struct acpi_video_output {
        ACPI_HANDLE     handle;
        UINT32          adr;
        STAILQ_ENTRY(acpi_video_output) vo_next;
        struct {
                int     num;
                STAILQ_ENTRY(acpi_video_output) next;
        } vo_unit;
        int             vo_brightness;
        int             vo_fullpower;
        int             vo_economy;
        int             vo_numlevels;
        int             *vo_levels;
        struct sysctl_ctx_list vo_sysctl_ctx;
        struct sysctl_oid *vo_sysctl_tree;
};

STAILQ_HEAD(acpi_video_output_queue, acpi_video_output);

struct acpi_video_softc {
        device_t                device;
        ACPI_HANDLE             handle;
        struct acpi_video_output_queue vid_outputs;
        eventhandler_tag        vid_pwr_evh;
};

/* interfaces */
static int      acpi_video_modevent(struct module*, int, void *);
static void     acpi_video_identify(driver_t *driver, device_t parent);
static int      acpi_video_probe(device_t);
static int      acpi_video_attach(device_t);
static int      acpi_video_detach(device_t);
static int      acpi_video_resume(device_t);
static int      acpi_video_shutdown(device_t);
static void     acpi_video_notify_handler(ACPI_HANDLE, UINT32, void *);
static void     acpi_video_power_profile(void *);
static void     acpi_video_bind_outputs(struct acpi_video_softc *);
static struct acpi_video_output *acpi_video_vo_init(UINT32);
static void     acpi_video_vo_bind(struct acpi_video_output *, ACPI_HANDLE);
static void     acpi_video_vo_destroy(struct acpi_video_output *);
static int      acpi_video_vo_check_level(struct acpi_video_output *, int);
static void     acpi_video_vo_notify_handler(ACPI_HANDLE, UINT32, void *);
static int      acpi_video_vo_active_sysctl(SYSCTL_HANDLER_ARGS);
static int      acpi_video_vo_bright_sysctl(SYSCTL_HANDLER_ARGS);
static int      acpi_video_vo_presets_sysctl(SYSCTL_HANDLER_ARGS);
static int      acpi_video_vo_levels_sysctl(SYSCTL_HANDLER_ARGS);

/* operations */
static void     vid_set_switch_policy(ACPI_HANDLE, UINT32);
static int      vid_enum_outputs(ACPI_HANDLE,
                    void(*)(ACPI_HANDLE, UINT32, void *), void *);
static int      vo_get_brightness_levels(ACPI_HANDLE, int **);
static int      vo_get_brightness(ACPI_HANDLE);
static void     vo_set_brightness(ACPI_HANDLE, int);
static UINT32   vo_get_device_status(ACPI_HANDLE);
static UINT32   vo_get_graphics_state(ACPI_HANDLE);
static void     vo_set_device_state(ACPI_HANDLE, UINT32);

/* events */
#define VID_NOTIFY_SWITCHED     0x80
#define VID_NOTIFY_REPROBE      0x81
#define VID_NOTIFY_CYCLE_BRN    0x85
#define VID_NOTIFY_INC_BRN      0x86
#define VID_NOTIFY_DEC_BRN      0x87
#define VID_NOTIFY_ZERO_BRN     0x88

/* _DOS (Enable/Disable Output Switching) argument bits */
#define DOS_SWITCH_MASK         3
#define DOS_SWITCH_BY_OSPM      0
#define DOS_SWITCH_BY_BIOS      1
#define DOS_SWITCH_LOCKED       2
#define DOS_BRIGHTNESS_BY_OSPM  (1 << 2)

/* _DOD and subdev's _ADR */
#define DOD_DEVID_MASK          0x0f00
#define DOD_DEVID_MASK_FULL     0xffff
#define DOD_DEVID_MASK_DISPIDX  0x000f
#define DOD_DEVID_MASK_DISPPORT 0x00f0
#define DOD_DEVID_MONITOR       0x0100
#define DOD_DEVID_LCD           0x0110
#define DOD_DEVID_TV            0x0200
#define DOD_DEVID_EXT           0x0300
#define DOD_DEVID_INTDFP        0x0400
#define DOD_BIOS                (1 << 16)
#define DOD_NONVGA              (1 << 17)
#define DOD_HEAD_ID_SHIFT       18
#define DOD_HEAD_ID_BITS        3
#define DOD_HEAD_ID_MASK \
                (((1 << DOD_HEAD_ID_BITS) - 1) << DOD_HEAD_ID_SHIFT)
#define DOD_DEVID_SCHEME_STD    (1 << 31)

/* _BCL related constants */
#define BCL_FULLPOWER           0
#define BCL_ECONOMY             1

/* _DCS (Device Currrent Status) value bits and masks. */
#define DCS_EXISTS              (1 << 0)
#define DCS_ACTIVE              (1 << 1)
#define DCS_READY               (1 << 2)
#define DCS_FUNCTIONAL          (1 << 3)
#define DCS_ATTACHED            (1 << 4)

/* _DSS (Device Set Status) argument bits and masks. */
#define DSS_INACTIVE            0
#define DSS_ACTIVE              (1 << 0)
#define DSS_SETNEXT             (1 << 30)
#define DSS_COMMIT              (1 << 31)

static device_method_t acpi_video_methods[] = {
        DEVMETHOD(device_identify, acpi_video_identify),
        DEVMETHOD(device_probe, acpi_video_probe),
        DEVMETHOD(device_attach, acpi_video_attach),
        DEVMETHOD(device_detach, acpi_video_detach),
        DEVMETHOD(device_resume, acpi_video_resume),
        DEVMETHOD(device_shutdown, acpi_video_shutdown),

        DEVMETHOD_END
};

static driver_t acpi_video_driver = {
        "acpi_video",
        acpi_video_methods,
        sizeof(struct acpi_video_softc),
};

static devclass_t acpi_video_devclass;

DRIVER_MODULE(acpi_video, vgapci, acpi_video_driver, acpi_video_devclass,
              acpi_video_modevent, NULL);
MODULE_DEPEND(acpi_video, acpi, 1, 1, 1);

static struct sysctl_ctx_list   acpi_video_sysctl_ctx;
static struct sysctl_oid        *acpi_video_sysctl_tree;
static struct acpi_video_output_queue crt_units, tv_units,
    ext_units, lcd_units, other_units;

/*
 * The 'video' lock protects the hierarchy of video output devices
 * (the video "bus").  The 'video_output' lock protects per-output
 * data is equivalent to a softc lock for each video output.
 */
ACPI_SERIAL_DECL(video, "ACPI video");
ACPI_SERIAL_DECL(video_output, "ACPI video output");
static MALLOC_DEFINE(M_ACPIVIDEO, "acpivideo", "ACPI video extension");

static int
acpi_video_modevent(struct module *mod __unused, int evt, void *cookie __unused)
{
        int err;

        err = 0;
        switch (evt) {
        case MOD_LOAD:
                sysctl_ctx_init(&acpi_video_sysctl_ctx);
                STAILQ_INIT(&crt_units);
                STAILQ_INIT(&tv_units);
                STAILQ_INIT(&ext_units);
                STAILQ_INIT(&lcd_units);
                STAILQ_INIT(&other_units);
                break;
        case MOD_UNLOAD:
                sysctl_ctx_free(&acpi_video_sysctl_ctx);
                acpi_video_sysctl_tree = NULL;
                break;
        default:
                err = EINVAL;
        }

        return (err);
}

static void
acpi_video_identify(driver_t *driver, device_t parent)
{

        if (device_find_child(parent, "acpi_video", -1) == NULL)
                device_add_child(parent, "acpi_video", -1);
}

static int
acpi_video_probe(device_t dev)
{
        ACPI_HANDLE devh, h;
        ACPI_OBJECT_TYPE t_dos;

        devh = acpi_get_handle(dev);
        if (acpi_disabled("video") ||
            ACPI_FAILURE(AcpiGetHandle(devh, "_DOD", &h)) ||
            ACPI_FAILURE(AcpiGetHandle(devh, "_DOS", &h)) ||
            ACPI_FAILURE(AcpiGetType(h, &t_dos)) ||
            t_dos != ACPI_TYPE_METHOD)
                return (ENXIO);

        device_set_desc(dev, "ACPI video extension");
        return (0);
}

static int
acpi_video_attach(device_t dev)
{
        struct acpi_softc *acpi_sc;
        struct acpi_video_softc *sc;

        sc = device_get_softc(dev);

        acpi_sc = devclass_get_softc(devclass_find("acpi"), 0);
        if (acpi_sc == NULL)
                return (ENXIO);
        ACPI_SERIAL_INIT(video);
        ACPI_SERIAL_INIT(video_output);
        ACPI_SERIAL_BEGIN(video);
        if (acpi_video_sysctl_tree == NULL) {
                acpi_video_sysctl_tree = SYSCTL_ADD_NODE(&acpi_video_sysctl_ctx,
                                    SYSCTL_CHILDREN(acpi_sc->acpi_sysctl_tree),
                                    OID_AUTO, "video", CTLFLAG_RD, 0,
                                    "video extension control");
        }
        ACPI_SERIAL_END(video);

        sc->device = dev;
        sc->handle = acpi_get_handle(dev);
        STAILQ_INIT(&sc->vid_outputs);

        AcpiInstallNotifyHandler(sc->handle, ACPI_DEVICE_NOTIFY,
                                 acpi_video_notify_handler, sc);
        sc->vid_pwr_evh = EVENTHANDLER_REGISTER(power_profile_change,
                                 acpi_video_power_profile, sc, 0);

        ACPI_SERIAL_BEGIN(video);
        acpi_video_bind_outputs(sc);
        ACPI_SERIAL_END(video);

        /*
         * Notify the BIOS that we want to switch both active outputs and
         * brightness levels.
         */
        vid_set_switch_policy(sc->handle, DOS_SWITCH_BY_OSPM |
            DOS_BRIGHTNESS_BY_OSPM);

        acpi_video_power_profile(sc);

        return (0);
}

static int
acpi_video_detach(device_t dev)
{
        struct acpi_video_softc *sc;
        struct acpi_video_output *vo, *vn;

        sc = device_get_softc(dev);

        vid_set_switch_policy(sc->handle, DOS_SWITCH_BY_BIOS);
        EVENTHANDLER_DEREGISTER(power_profile_change, sc->vid_pwr_evh);
        AcpiRemoveNotifyHandler(sc->handle, ACPI_DEVICE_NOTIFY,
                                acpi_video_notify_handler);

        ACPI_SERIAL_BEGIN(video);
        STAILQ_FOREACH_MUTABLE(vo, &sc->vid_outputs, vo_next, vn) {
                acpi_video_vo_destroy(vo);
        }
        ACPI_SERIAL_END(video);

        return (0);
}

static int
acpi_video_resume(device_t dev)
{
        struct acpi_video_softc *sc;
        struct acpi_video_output *vo, *vn;
        int level;

        sc = device_get_softc(dev);

        /* Restore brightness level */
        ACPI_SERIAL_BEGIN(video);
        ACPI_SERIAL_BEGIN(video_output);
        STAILQ_FOREACH_MUTABLE(vo, &sc->vid_outputs, vo_next, vn) {
                if ((vo->adr & DOD_DEVID_MASK_FULL) != DOD_DEVID_LCD &&
                    (vo->adr & DOD_DEVID_MASK) != DOD_DEVID_INTDFP)
                        continue;

                if ((vo_get_device_status(vo->handle) & DCS_ACTIVE) == 0)
                        continue;

                level = vo_get_brightness(vo->handle);
                if (level != -1)
                        vo_set_brightness(vo->handle, level);
        }
        ACPI_SERIAL_END(video_output);
        ACPI_SERIAL_END(video);

        return (0);
}

static int
acpi_video_shutdown(device_t dev)
{
        struct acpi_video_softc *sc;

        sc = device_get_softc(dev);
        vid_set_switch_policy(sc->handle, DOS_SWITCH_BY_BIOS);

        return (0);
}

static void
acpi_video_notify_handler(ACPI_HANDLE handle, UINT32 notify, void *context)
{
        struct acpi_video_softc *sc;
        struct acpi_video_output *vo, *vo_tmp;
        ACPI_HANDLE lasthand;
        UINT32 dcs, dss, dss_p;

        sc = (struct acpi_video_softc *)context;

        switch (notify) {
        case VID_NOTIFY_SWITCHED:
                dss_p = 0;
                lasthand = NULL;
                ACPI_SERIAL_BEGIN(video);
                ACPI_SERIAL_BEGIN(video_output);
                STAILQ_FOREACH(vo, &sc->vid_outputs, vo_next) {
                        dss = vo_get_graphics_state(vo->handle);
                        dcs = vo_get_device_status(vo->handle);
                        if (!(dcs & DCS_READY))
                                dss = DSS_INACTIVE;
                        if (((dcs & DCS_ACTIVE) && dss == DSS_INACTIVE) ||
                            (!(dcs & DCS_ACTIVE) && dss == DSS_ACTIVE)) {
                                if (lasthand != NULL)
                                        vo_set_device_state(lasthand, dss_p);
                                dss_p = dss;
                                lasthand = vo->handle;
                        }
                }
                if (lasthand != NULL)
                        vo_set_device_state(lasthand, dss_p|DSS_COMMIT);
                ACPI_SERIAL_END(video_output);
                ACPI_SERIAL_END(video);
                break;
        case VID_NOTIFY_REPROBE:
                ACPI_SERIAL_BEGIN(video);
                STAILQ_FOREACH(vo, &sc->vid_outputs, vo_next)
                        vo->handle = NULL;
                acpi_video_bind_outputs(sc);
                STAILQ_FOREACH_MUTABLE(vo, &sc->vid_outputs, vo_next, vo_tmp) {
                        if (vo->handle == NULL) {
                                STAILQ_REMOVE(&sc->vid_outputs, vo,
                                    acpi_video_output, vo_next);
                                acpi_video_vo_destroy(vo);
                        }
                }
                ACPI_SERIAL_END(video);
                break;
        default:
                device_printf(sc->device, "unknown notify: %#x\n", notify);
        }
}

static void
acpi_video_power_profile(void *context)
{
        int state;
        struct acpi_video_softc *sc;
        struct acpi_video_output *vo;

        sc = context;
        state = power_profile_get_state();
        if (state != POWER_PROFILE_PERFORMANCE &&
            state != POWER_PROFILE_ECONOMY)
                return;

        ACPI_SERIAL_BEGIN(video);
        ACPI_SERIAL_BEGIN(video_output);
        STAILQ_FOREACH(vo, &sc->vid_outputs, vo_next) {
                if (vo->vo_levels != NULL && vo->vo_brightness == -1)
                        vo_set_brightness(vo->handle,
                            state == POWER_PROFILE_ECONOMY ?
                            vo->vo_economy : vo->vo_fullpower);
        }
        ACPI_SERIAL_END(video_output);
        ACPI_SERIAL_END(video);
}

static void
acpi_video_bind_outputs_subr(ACPI_HANDLE handle, UINT32 adr, void *context)
{
        struct acpi_video_softc *sc;
        struct acpi_video_output *vo;

        ACPI_SERIAL_ASSERT(video);
        sc = context;

        STAILQ_FOREACH(vo, &sc->vid_outputs, vo_next) {
                if (vo->adr == adr) {
                        acpi_video_vo_bind(vo, handle);
                        return;
                }
        }
        vo = acpi_video_vo_init(adr);
        if (vo != NULL) {
                acpi_video_vo_bind(vo, handle);
                STAILQ_INSERT_TAIL(&sc->vid_outputs, vo, vo_next);
        }
}

static void
acpi_video_bind_outputs(struct acpi_video_softc *sc)
{
        ACPI_SERIAL_ASSERT(video);
        vid_enum_outputs(sc->handle, acpi_video_bind_outputs_subr, sc);
}

static struct acpi_video_output *
acpi_video_vo_init(UINT32 adr)
{
        struct acpi_video_output *vn, *vo, *vp;
        int n, x;
        char name[8], env[32];
        const char *type, *desc;
        struct acpi_video_output_queue *voqh;

        ACPI_SERIAL_ASSERT(video);

        switch (adr & DOD_DEVID_MASK) {
        case DOD_DEVID_MONITOR:
                if ((adr & DOD_DEVID_MASK_FULL) == DOD_DEVID_LCD) {
                        /* DOD_DEVID_LCD is a common, backward compatible ID */
                        desc = "Internal/Integrated Digital Flat Panel";
                        type = "lcd";
                        voqh = &lcd_units;
                } else {
                        desc = "VGA CRT or VESA Compatible Analog Monitor";
                        type = "crt";
                        voqh = &crt_units;
                }
                break;
        case DOD_DEVID_TV:
                desc = "TV/HDTV or Analog-Video Monitor";
                type = "tv";
                voqh = &tv_units;
                break;
        case DOD_DEVID_EXT:
                desc = "External Digital Monitor";
                type = "ext";
                voqh = &ext_units;
                break;
        case DOD_DEVID_INTDFP:
                desc = "Internal/Integrated Digital Flat Panel";
                type = "lcd";
                voqh = &lcd_units;
                break;
        default:
                desc = "unknown output";
                type = "out";
                voqh = &other_units;
        }

        n = 0;
        vp = NULL;
        STAILQ_FOREACH(vn, voqh, vo_unit.next) {
                if (vn->vo_unit.num != n)
                        break;
                vp = vn;
                n++;
        }

        ksnprintf(name, sizeof(name), "%s%d", type, n);

        vo = kmalloc(sizeof(*vo), M_ACPIVIDEO, M_NOWAIT);
        if (vo != NULL) {
                vo->handle = NULL;
                vo->adr = adr;
                vo->vo_unit.num = n;
                vo->vo_brightness = -1;
                vo->vo_fullpower = -1;  /* TODO: override with tunables */
                vo->vo_economy = -1;
                vo->vo_numlevels = 0;
                vo->vo_levels = NULL;
                ksnprintf(env, sizeof(env), "hw.acpi.video.%s.fullpower", name);
                if (kgetenv_int(env, &x))
                        vo->vo_fullpower = x;
                ksnprintf(env, sizeof(env), "hw.acpi.video.%s.economy", name);
                if (kgetenv_int(env, &x))
                        vo->vo_economy = x;

                sysctl_ctx_init(&vo->vo_sysctl_ctx);
                if (vp != NULL)
                        STAILQ_INSERT_AFTER(voqh, vp, vo, vo_unit.next);
                else
                        STAILQ_INSERT_TAIL(voqh, vo, vo_unit.next);
                if (acpi_video_sysctl_tree != NULL)
                        vo->vo_sysctl_tree =
                            SYSCTL_ADD_NODE(&vo->vo_sysctl_ctx,
                                SYSCTL_CHILDREN(acpi_video_sysctl_tree),
                                OID_AUTO, name, CTLFLAG_RD, 0, desc);
                if (vo->vo_sysctl_tree != NULL) {
                        SYSCTL_ADD_PROC(&vo->vo_sysctl_ctx,
                            SYSCTL_CHILDREN(vo->vo_sysctl_tree),
                            OID_AUTO, "active",
                            CTLTYPE_INT|CTLFLAG_RW, vo, 0,
                            acpi_video_vo_active_sysctl, "I",
                            "current activity of this device");
                        SYSCTL_ADD_PROC(&vo->vo_sysctl_ctx,
                            SYSCTL_CHILDREN(vo->vo_sysctl_tree),
                            OID_AUTO, "brightness",
                            CTLTYPE_INT|CTLFLAG_RW, vo, 0,
                            acpi_video_vo_bright_sysctl, "I",
                            "current brightness level");
                        SYSCTL_ADD_PROC(&vo->vo_sysctl_ctx,
                            SYSCTL_CHILDREN(vo->vo_sysctl_tree),
                            OID_AUTO, "fullpower",
                            CTLTYPE_INT|CTLFLAG_RW, vo,
                            POWER_PROFILE_PERFORMANCE,
                            acpi_video_vo_presets_sysctl, "I",
                            "preset level for full power mode");
                        SYSCTL_ADD_PROC(&vo->vo_sysctl_ctx,
                            SYSCTL_CHILDREN(vo->vo_sysctl_tree),
                            OID_AUTO, "economy",
                            CTLTYPE_INT|CTLFLAG_RW, vo,
                            POWER_PROFILE_ECONOMY,
                            acpi_video_vo_presets_sysctl, "I",
                            "preset level for economy mode");
                        SYSCTL_ADD_PROC(&vo->vo_sysctl_ctx,
                            SYSCTL_CHILDREN(vo->vo_sysctl_tree),
                            OID_AUTO, "levels",
                            CTLTYPE_INT|CTLFLAG_RD, vo, 0,
                            acpi_video_vo_levels_sysctl, "I",
                            "supported brightness levels");
                } else
                        kprintf("%s: sysctl node creation failed\n", type);
        } else
                kprintf("%s: softc allocation failed\n", type);

        if (bootverbose) {
                kprintf("found %s(%x)", desc, adr & DOD_DEVID_MASK_FULL);
                kprintf(", idx#%x", adr & DOD_DEVID_MASK_DISPIDX);
                kprintf(", port#%x", (adr & DOD_DEVID_MASK_DISPPORT) >> 4);
                if (adr & DOD_BIOS)
                        kprintf(", detectable by BIOS");
                if (adr & DOD_NONVGA)
                        kprintf(" (Non-VGA output device whose power "
                            "is related to the VGA device)");
                kprintf(", head #%d\n",
                        (adr & DOD_HEAD_ID_MASK) >> DOD_HEAD_ID_SHIFT);
        }
        return (vo);
}

static void
acpi_video_vo_bind(struct acpi_video_output *vo, ACPI_HANDLE handle)
{
        ACPI_SERIAL_BEGIN(video_output);
        if (vo->vo_levels != NULL)
                AcpiOsFree(vo->vo_levels);
        vo->handle = handle;
        vo->vo_numlevels = vo_get_brightness_levels(handle, &vo->vo_levels);
        if (vo->vo_numlevels >= 2) {
                if (vo->vo_fullpower == -1
                    || acpi_video_vo_check_level(vo, vo->vo_fullpower) != 0)
                        /* XXX - can't deal with rebinding... */
                        vo->vo_fullpower = vo->vo_levels[BCL_FULLPOWER];
                if (vo->vo_economy == -1
                    || acpi_video_vo_check_level(vo, vo->vo_economy) != 0)
                        /* XXX - see above. */
                        vo->vo_economy = vo->vo_levels[BCL_ECONOMY];
        }
        if (vo->vo_levels != NULL)
                AcpiInstallNotifyHandler(handle, ACPI_DEVICE_NOTIFY,
                    acpi_video_vo_notify_handler, vo);
        ACPI_SERIAL_END(video_output);
}

static void
acpi_video_vo_destroy(struct acpi_video_output *vo)
{
        struct acpi_video_output_queue *voqh;

        ACPI_SERIAL_ASSERT(video);
        if (vo->vo_sysctl_tree != NULL) {
                vo->vo_sysctl_tree = NULL;
                sysctl_ctx_free(&vo->vo_sysctl_ctx);
        }
        if (vo->vo_levels != NULL) {
                AcpiRemoveNotifyHandler(vo->handle, ACPI_DEVICE_NOTIFY,
                    acpi_video_vo_notify_handler);
                AcpiOsFree(vo->vo_levels);
        }

        switch (vo->adr & DOD_DEVID_MASK) {
        case DOD_DEVID_MONITOR:
                if ((vo->adr & DOD_DEVID_MASK_FULL) == DOD_DEVID_LCD) {
                        voqh = &lcd_units;
                } else {
                        voqh = &crt_units;
                }
                break;
        case DOD_DEVID_TV:
                voqh = &tv_units;
                break;
        case DOD_DEVID_EXT:
                voqh = &ext_units;
                break;
        case DOD_DEVID_INTDFP:
                voqh = &lcd_units;
                break;
        default:
                voqh = &other_units;
        }
        STAILQ_REMOVE(voqh, vo, acpi_video_output, vo_unit.next);
        kfree(vo, M_ACPIVIDEO);
}

static int
acpi_video_vo_check_level(struct acpi_video_output *vo, int level)
{
        int i;

        ACPI_SERIAL_ASSERT(video_output);
        if (vo->vo_levels == NULL)
                return (ENODEV);
        for (i = 0; i < vo->vo_numlevels; i++)
                if (vo->vo_levels[i] == level)
                        return (0);
        return (EINVAL);
}

static void
acpi_video_vo_notify_handler(ACPI_HANDLE handle, UINT32 notify, void *context)
{
        struct acpi_video_output *vo;
        int i, j, level, new_level;

        vo = context;
        ACPI_SERIAL_BEGIN(video_output);
        if (vo->handle != handle)
                goto out;

        switch (notify) {
        case VID_NOTIFY_CYCLE_BRN:
                if (vo->vo_numlevels <= 3)
                        goto out;
                /* FALLTHROUGH */
        case VID_NOTIFY_INC_BRN:
        case VID_NOTIFY_DEC_BRN:
        case VID_NOTIFY_ZERO_BRN:
                if (vo->vo_levels == NULL)
                        goto out;
                level = vo_get_brightness(handle);
                if (level < 0)
                        goto out;
                break;
        default:
                kprintf("unknown notify: %#x from %s\n", notify,
                    acpi_name(handle));
                goto out;
        }

        new_level = level;
        switch (notify) {
        case VID_NOTIFY_CYCLE_BRN:
                for (i = 2; i < vo->vo_numlevels; i++)
                        if (vo->vo_levels[i] == level) {
                                new_level = vo->vo_numlevels > i + 1 ?
                                     vo->vo_levels[i + 1] : vo->vo_levels[2];
                                break;
                        }
                break;
        case VID_NOTIFY_INC_BRN:
        case VID_NOTIFY_DEC_BRN:
                for (i = 0; i < vo->vo_numlevels; i++) {
                        j = vo->vo_levels[i];
                        if (notify == VID_NOTIFY_INC_BRN) {
                                if (j > level &&
                                    (j < new_level || level == new_level))
                                        new_level = j;
                        } else {
                                if (j < level &&
                                    (j > new_level || level == new_level))
                                        new_level = j;
                        }
                }
                break;
        case VID_NOTIFY_ZERO_BRN:
                for (i = 0; i < vo->vo_numlevels; i++)
                        if (vo->vo_levels[i] == 0) {
                                new_level = 0;
                                break;
                        }
                break;
        }
        if (new_level != level) {
                vo_set_brightness(handle, new_level);
                vo->vo_brightness = new_level;
        }

out:
        ACPI_SERIAL_END(video_output);
}

/* ARGSUSED */
static int
acpi_video_vo_active_sysctl(SYSCTL_HANDLER_ARGS)
{
        struct acpi_video_output *vo;
        int state, err;

        vo = (struct acpi_video_output *)arg1;
        if (vo->handle == NULL)
                return (ENXIO);
        ACPI_SERIAL_BEGIN(video_output);
        state = (vo_get_device_status(vo->handle) & DCS_ACTIVE) ? 1 : 0;
        err = sysctl_handle_int(oidp, &state, 0, req);
        if (err != 0 || req->newptr == NULL)
                goto out;
        vo_set_device_state(vo->handle,
            DSS_COMMIT | (state ? DSS_ACTIVE : DSS_INACTIVE));
out:
        ACPI_SERIAL_END(video_output);
        return (err);
}

/* ARGSUSED */
static int
acpi_video_vo_bright_sysctl(SYSCTL_HANDLER_ARGS)
{
        struct acpi_video_output *vo;
        int level, preset, err;

        vo = (struct acpi_video_output *)arg1;
        ACPI_SERIAL_BEGIN(video_output);
        if (vo->handle == NULL) {
                err = ENXIO;
                goto out;
        }
        if (vo->vo_levels == NULL) {
                err = ENODEV;
                goto out;
        }

        preset = (power_profile_get_state() == POWER_PROFILE_ECONOMY) ?
                  vo->vo_economy : vo->vo_fullpower;
        level = vo->vo_brightness;
        if (level == -1)
                level = preset;

        err = sysctl_handle_int(oidp, &level, 0, req);
        if (err != 0 || req->newptr == NULL)
                goto out;
        if (level < -1 || level > 100) {
                err = EINVAL;
                goto out;
        }

        if (level != -1 && (err = acpi_video_vo_check_level(vo, level)))
                goto out;
        vo->vo_brightness = level;
        vo_set_brightness(vo->handle, (level == -1) ? preset : level);

out:
        ACPI_SERIAL_END(video_output);
        return (err);
}

static int
acpi_video_vo_presets_sysctl(SYSCTL_HANDLER_ARGS)
{
        struct acpi_video_output *vo;
        int i, level, *preset, err;

        vo = (struct acpi_video_output *)arg1;
        ACPI_SERIAL_BEGIN(video_output);
        if (vo->handle == NULL) {
                err = ENXIO;
                goto out;
        }
        if (vo->vo_levels == NULL) {
                err = ENODEV;
                goto out;
        }
        preset = (arg2 == POWER_PROFILE_ECONOMY) ?
                  &vo->vo_economy : &vo->vo_fullpower;
        level = *preset;
        err = sysctl_handle_int(oidp, &level, 0, req);
        if (err != 0 || req->newptr == NULL)
                goto out;
        if (level < -1 || level > 100) {
                err = EINVAL;
                goto out;
        }
        if (level == -1) {
                i = (arg2 == POWER_PROFILE_ECONOMY) ?
                    BCL_ECONOMY : BCL_FULLPOWER;
                level = vo->vo_levels[i];
        } else if ((err = acpi_video_vo_check_level(vo, level)) != 0)
                goto out;

        if (vo->vo_brightness == -1 && (power_profile_get_state() == arg2))
                vo_set_brightness(vo->handle, level);
        *preset = level;

out:
        ACPI_SERIAL_END(video_output);
        return (err);
}

/* ARGSUSED */
static int
acpi_video_vo_levels_sysctl(SYSCTL_HANDLER_ARGS)
{
        struct acpi_video_output *vo;
        int err;

        vo = (struct acpi_video_output *)arg1;
        ACPI_SERIAL_BEGIN(video_output);
        if (vo->vo_levels == NULL) {
                err = ENODEV;
                goto out;
        }
        if (req->newptr != NULL) {
                err = EPERM;
                goto out;
        }
        err = sysctl_handle_opaque(oidp, vo->vo_levels,
            vo->vo_numlevels * sizeof(*vo->vo_levels), req);

out:
        ACPI_SERIAL_END(video_output);
        return (err);
}

static void
vid_set_switch_policy(ACPI_HANDLE handle, UINT32 policy)
{
        ACPI_STATUS status;

        status = acpi_SetInteger(handle, "_DOS", policy);
        if (ACPI_FAILURE(status))
                kprintf("can't evaluate %s._DOS - %s\n",
                       acpi_name(handle), AcpiFormatException(status));
}

struct enum_callback_arg {
        void (*callback)(ACPI_HANDLE, UINT32, void *);
        void *context;
        ACPI_OBJECT *dod_pkg;
        int count;
};

static ACPI_STATUS
vid_enum_outputs_subr(ACPI_HANDLE handle, UINT32 level __unused,
                      void *context, void **retp __unused)
{
        ACPI_STATUS status;
        UINT32 adr, val;
        struct enum_callback_arg *argset;
        size_t i;

        ACPI_SERIAL_ASSERT(video);
        argset = context;
        status = acpi_GetInteger(handle, "_ADR", &adr);
        if (ACPI_FAILURE(status))
                return (AE_OK);

        for (i = 0; i < argset->dod_pkg->Package.Count; i++) {
                if (acpi_PkgInt32(argset->dod_pkg, i, &val) == 0 &&
                    (val & DOD_DEVID_MASK_FULL) ==
                    (adr & DOD_DEVID_MASK_FULL)) {
                        argset->callback(handle, val, argset->context);
                        argset->count++;
                }
        }

        return (AE_OK);
}

static int
vid_enum_outputs(ACPI_HANDLE handle,
                 void (*callback)(ACPI_HANDLE, UINT32, void *), void *context)
{
        ACPI_STATUS status;
        ACPI_BUFFER dod_buf;
        ACPI_OBJECT *res;
        struct enum_callback_arg argset;

        ACPI_SERIAL_ASSERT(video);
        dod_buf.Length = ACPI_ALLOCATE_BUFFER;
        dod_buf.Pointer = NULL;
        status = AcpiEvaluateObject(handle, "_DOD", NULL, &dod_buf);
        if (ACPI_FAILURE(status)) {
                if (status != AE_NOT_FOUND)
                        kprintf("can't evaluate %s._DOD - %s\n",
                               acpi_name(handle), AcpiFormatException(status));
                argset.count = -1;
                goto out;
        }
        res = (ACPI_OBJECT *)dod_buf.Pointer;
        if (!ACPI_PKG_VALID(res, 1)) {
                kprintf("evaluation of %s._DOD makes no sense\n",
                       acpi_name(handle));
                argset.count = -1;
                goto out;
        }
        if (callback == NULL) {
                argset.count = res->Package.Count;
                goto out;
        }
        argset.callback = callback;
        argset.context  = context;
        argset.dod_pkg  = res;
        argset.count    = 0;
        status = AcpiWalkNamespace(ACPI_TYPE_DEVICE, handle, 1,
            vid_enum_outputs_subr, NULL, &argset, NULL);
        if (ACPI_FAILURE(status))
                kprintf("failed walking down %s - %s\n",
                       acpi_name(handle), AcpiFormatException(status));
out:
        if (dod_buf.Pointer != NULL)
                AcpiOsFree(dod_buf.Pointer);
        return (argset.count);
}

static int
vo_get_brightness_levels(ACPI_HANDLE handle, int **levelp)
{
        ACPI_STATUS status;
        ACPI_BUFFER bcl_buf;
        ACPI_OBJECT *res;
        int num, i, n, *levels;

        bcl_buf.Length = ACPI_ALLOCATE_BUFFER;
        bcl_buf.Pointer = NULL;
        status = AcpiEvaluateObject(handle, "_BCL", NULL, &bcl_buf);
        if (ACPI_FAILURE(status)) {
                if (status != AE_NOT_FOUND)
                        kprintf("can't evaluate %s._BCL - %s\n",
                               acpi_name(handle), AcpiFormatException(status));
                goto out;
        }
        res = (ACPI_OBJECT *)bcl_buf.Pointer;
        if (!ACPI_PKG_VALID(res, 2)) {
                kprintf("evaluation of %s._BCL makes no sense\n",
                       acpi_name(handle));
                goto out;
        }
        num = res->Package.Count;
        if (num < 2 || levelp == NULL)
                goto out;
        levels = AcpiOsAllocate(num * sizeof(*levels));
        if (levels == NULL)
                goto out;
        for (i = 0, n = 0; i < num; i++)
                if (acpi_PkgInt32(res, i, &levels[n]) == 0)
                        n++;
        if (n < 2) {
                AcpiOsFree(levels);
                goto out;
        }
        *levelp = levels;
        return (n);

out:
        if (bcl_buf.Pointer != NULL)
                AcpiOsFree(bcl_buf.Pointer);
        return (0);
}

static int
vo_get_brightness(ACPI_HANDLE handle)
{
        UINT32 level;
        ACPI_STATUS status;

        ACPI_SERIAL_ASSERT(video_output);
        status = acpi_GetInteger(handle, "_BQC", &level);
        if (ACPI_FAILURE(status)) {
                kprintf("can't evaluate %s._BQC - %s\n", acpi_name(handle),
                    AcpiFormatException(status));
                return (-1);
        }
        if (level > 100)
                return (-1);

        return (level);
}

static void
vo_set_brightness(ACPI_HANDLE handle, int level)
{
        ACPI_STATUS status;

        ACPI_SERIAL_ASSERT(video_output);
        status = acpi_SetInteger(handle, "_BCM", level);
        if (ACPI_FAILURE(status))
                kprintf("can't evaluate %s._BCM - %s\n",
                       acpi_name(handle), AcpiFormatException(status));
}

static UINT32
vo_get_device_status(ACPI_HANDLE handle)
{
        UINT32 dcs;
        ACPI_STATUS status;

        ACPI_SERIAL_ASSERT(video_output);
        dcs = 0;
        status = acpi_GetInteger(handle, "_DCS", &dcs);
        if (ACPI_FAILURE(status))
                kprintf("can't evaluate %s._DCS - %s\n",
                       acpi_name(handle), AcpiFormatException(status));

        return (dcs);
}

static UINT32
vo_get_graphics_state(ACPI_HANDLE handle)
{
        UINT32 dgs;
        ACPI_STATUS status;

        dgs = 0;
        status = acpi_GetInteger(handle, "_DGS", &dgs);
        if (ACPI_FAILURE(status))
                kprintf("can't evaluate %s._DGS - %s\n",
                       acpi_name(handle), AcpiFormatException(status));

        return (dgs);
}

static void
vo_set_device_state(ACPI_HANDLE handle, UINT32 state)
{
        ACPI_STATUS status;

        ACPI_SERIAL_ASSERT(video_output);
        status = acpi_SetInteger(handle, "_DSS", state);
        if (ACPI_FAILURE(status))
                kprintf("can't evaluate %s._DSS - %s\n",
                       acpi_name(handle), AcpiFormatException(status));
}