/*-
 * 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.
 *
 *	$Id: acpi_vid.c,v 1.4 2003/10/13 10:07:36 taku Exp $
 *	$FreeBSD$
 */

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

#include "acpi.h"
#include <dev/acpica/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;
	STAILQ_HEAD(, acpi_video_output) vid_outputs;
	eventhandler_tag	vid_pwr_evh;
};

/* interfaces */
static int	acpi_video_modevent(struct module*, int, void *);
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_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 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 int	vid_check_requirements(ACPI_HANDLE);
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_query_brightness_levels(ACPI_HANDLE, int **);
static void	vo_set_brightness(ACPI_HANDLE, int);
static UINT32	vo_get_device_status(ACPI_HANDLE);
static UINT32	vo_query_graphics_state(ACPI_HANDLE);
static void	vo_set_device_state(ACPI_HANDLE, UINT32);

/* events */
#define VID_NOTIFY_SWITCHED	0x80
#define VID_NOTIFY_REPROBE	0x81

/* _DOS (Enable/Disable Output Switching) argument bits */
#define DOS_SWITCH_MASK		((UINT32)3)
#define DOS_SWITCH_BY_OSPM	((UINT32)0)
#define DOS_SWITCH_BY_BIOS	((UINT32)1)
#define DOS_SWITCH_LOCKED	((UINT32)2)
#define DOS_BRIGHTNESS_BY_BIOS	((UINT32)1 << 2)

/* _DOD and subdev's _ADR */
#define DOD_DEVID_MASK		((UINT32)0xffff)
#define DOD_DEVID_MONITOR	((UINT32)0x0100)
#define DOD_DEVID_PANEL		((UINT32)0x0110)
#define DOD_DEVID_TV		((UINT32)0x0200)
#define DOD_BIOS		((UINT32)1 << 16)
#define DOD_NONVGA		((UINT32)1 << 17)
#define DOD_HEAD_ID_SHIFT	18
#define DOD_HEAD_ID_BITS	3
#define DOD_HEAD_ID_MASK \
		((((UINT32)1 << DOD_HEAD_ID_BITS) - 1) << DOD_HEAD_ID_SHIFT)

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

/* _DCS (Device Currrent Status) value bits and masks. */
#define DCS_EXISTS		((UINT32)1 << 0)
#define DCS_ACTIVE		((UINT32)1 << 1)
#define DCS_READY		((UINT32)1 << 2)
#define DCS_FUNCTIONAL		((UINT32)1 << 3)
#define DCS_ATTACHED		((UINT32)1 << 4)

/* _DSS (Device Set Status) argument bits and masks. */
#define DSS_INACTIVE		((UINT32)0)
#define DSS_ACTIVE		((UINT32)1 << 0)
#define DSS_ACTIVITY		((UINT32)1 << 0)
#define DSS_SETNEXT		((UINT32)1 << 30)
#define DSS_COMMIT		((UINT32)1 << 31)

static device_method_t acpi_video_methods[] = {
	DEVMETHOD(device_probe, acpi_video_probe),
	DEVMETHOD(device_attach, acpi_video_attach),
	DEVMETHOD(device_detach, acpi_video_detach),
	DEVMETHOD(device_shutdown, acpi_video_shutdown),
	{ 0, 0 }
};

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, acpi, acpi_video_driver, acpi_video_devclass,
	      acpi_video_modevent, NULL);
MODULE_DEPEND(acpi_video, acpi, 100, 100, 100);

struct sysctl_ctx_list	acpi_video_sysctl_ctx;
struct sysctl_oid	*acpi_video_sysctl_tree;

static struct acpi_video_output_queue
		lcd_units, crt_units, tv_units, other_units;

MALLOC_DEFINE(M_ACPIVIDEO, "acpivideo", "ACPI video extension");

static int
acpi_video_modevent(struct module *mod __unused, int evt, void *cookie __unused)
{
	int err = 0;

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

	return (err);
}

static int
acpi_video_probe(device_t dev)
{
	int err = ENXIO;
	ACPI_HANDLE handle;
	ACPI_LOCK_DECL;

	ACPI_LOCK;
	handle = acpi_get_handle(dev);
	if (acpi_get_type(dev) == ACPI_TYPE_DEVICE &&
	    !acpi_disabled("video") &&
	    vid_check_requirements(handle)) {
		device_set_desc(dev, "ACPI video extension");
		err = 0;
	}
	ACPI_UNLOCK;

	return (err);
}

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

	sc = device_get_softc(dev);
	ACPI_LOCK;

	acpi_sc = acpi_device_get_parent_softc(dev);
	if (acpi_video_sysctl_tree == NULL && acpi_sc != 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");
	}

	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_video_bind_outputs(sc);
	vid_set_switch_policy(sc->handle, DOS_SWITCH_BY_OSPM);

	ACPI_UNLOCK;
	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;
	ACPI_LOCK_DECL;

	sc = device_get_softc(dev);
	ACPI_LOCK;

	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);

	for (vo = STAILQ_FIRST(&sc->vid_outputs); vo != NULL; vo = vn) {
		vn = STAILQ_NEXT(vo, vo_next);
		acpi_video_vo_destroy(vo);
	}

	ACPI_UNLOCK;
	return (0);
}

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

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

	return (0);
}

static void
acpi_video_notify_handler(ACPI_HANDLE handle __unused, UINT32 notify, void *context)
{
	struct acpi_video_softc *sc;
	struct acpi_video_output *vo;
	ACPI_HANDLE lasthand = NULL;
	UINT32 dcs, dss, dss_p = 0;

	ACPI_ASSERTLOCK;
	sc = context;

	switch (notify) {
	case VID_NOTIFY_SWITCHED:
		STAILQ_FOREACH(vo, &sc->vid_outputs, vo_next) {
			dss = vo_query_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);
		break;
	case VID_NOTIFY_REPROBE:
		STAILQ_FOREACH(vo, &sc->vid_outputs, vo_next)
			vo->handle = NULL;
		acpi_video_bind_outputs(sc);
		STAILQ_FOREACH(vo, &sc->vid_outputs, vo_next) {
			if (vo->handle == NULL) {
				STAILQ_REMOVE(&sc->vid_outputs, vo,
					      acpi_video_output, vo_next);
				acpi_video_vo_destroy(vo);
			}
		}
		break;
	default:
		device_printf(sc->device,
			      "unknown notify event 0x%x\n", notify);
	}
}

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

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

	ACPI_LOCK;
	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_UNLOCK;
}

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

	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_ASSERTLOCK;

	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[64], env[128];
	const char *type, *desc;
	struct acpi_video_output_queue *voqh;

	switch (adr & DOD_DEVID_MASK) {
	case DOD_DEVID_MONITOR:
		desc = "CRT monitor";
		type = "crt";
		voqh = &crt_units;
		break;
	case DOD_DEVID_PANEL:
		desc = "LCD panel";
		type = "lcd";
		voqh = &lcd_units;
		break;
	case DOD_DEVID_TV:
		desc = "TV";
		type = "tv";
		voqh = &tv_units;
		break;
	default:
		desc = "unknown output";
		type = "out";
		voqh = &other_units;
	}

	n = 0;
	vn = vp = NULL;
	/* XXX - needs locking for protecting STAILQ xxx_units. */
	STAILQ_FOREACH(vn, voqh, vo_unit.next) {
		if (vn->vo_unit.num != n)
			break;
		vp = vn;
		n++;
	}

	snprintf(name, 64, "%s%d", type, n);

	vo = malloc(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;
		snprintf(env, 128, "hw.acpi.video.%s.fullpower", name);
		if (getenv_int(env, &x))
			vo->vo_fullpower = x;
		snprintf(env, 128, "hw.acpi.video.%s.economy", name);
		if (getenv_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_OPAQUE|CTLFLAG_RD, vo, 0,
					acpi_video_vo_levels_sysctl, "I",
					"supported brightness levels");
		} else
			printf("%s: sysctl node creation failed\n", type);
	} else
		printf("%s: softc allocation failed\n", type);

	/* XXX unlock here - needs locking for protecting STAILQ xxx_units. */

	if (bootverbose) {
		printf("found %s(%x)", desc,
		       (unsigned int)(adr & DOD_DEVID_MASK));
		if (adr & DOD_BIOS)
			printf(", detectable by BIOS");
		if (adr & DOD_NONVGA)
			printf(" (not a VGA output)");
		printf(", head #%d\n",
		       (int)((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_ASSERTLOCK;

	if (vo->vo_levels != NULL)
		AcpiOsFree(vo->vo_levels);
	vo->handle = handle;
	vo->vo_numlevels
		= vo_query_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];
	}
}

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

	ACPI_ASSERTLOCK;

	if (vo->vo_sysctl_tree != NULL) {
		vo->vo_sysctl_tree = NULL;
		sysctl_ctx_free(&vo->vo_sysctl_ctx);
	}
	if (vo->vo_levels != NULL)
		AcpiOsFree(vo->vo_levels);

	switch (vo->adr & DOD_DEVID_MASK) {
	case DOD_DEVID_MONITOR:
		voqh = &crt_units;
		break;
	case DOD_DEVID_PANEL:
		voqh = &lcd_units;
		break;
	case DOD_DEVID_TV:
		voqh = &tv_units;
		break;
	default:
		voqh = &other_units;
	}
	/* XXX - needs locking for protecting STAILQ xxx_units. */
	STAILQ_REMOVE(voqh, vo, acpi_video_output, vo_unit.next);
	free(vo, M_ACPIVIDEO);
}

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

	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);
}

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

	ACPI_LOCK;
	vo = (struct acpi_video_output *)arg1;
	if (vo->handle == NULL) {
		err = ENXIO;
		goto out;
	}
	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_UNLOCK;
	return (err);
}

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

	ACPI_LOCK;
	vo = (struct acpi_video_output *)arg1;
	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_UNLOCK;
	return (err);
}

static int
acpi_video_vo_presets_sysctl(SYSCTL_HANDLER_ARGS)
{
	struct acpi_video_output *vo;
	int level, *preset, err = 0;
	ACPI_LOCK_DECL;

	ACPI_LOCK;
	vo = (struct acpi_video_output *)arg1;
	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)
		level = vo->vo_levels
			[arg2 == POWER_PROFILE_ECONOMY
			 ? BCL_ECONOMY : BCL_FULLPOWER];
	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_UNLOCK;
	return (err);
}

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

	ACPI_LOCK;
	vo = (struct acpi_video_output *)arg1;
	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_UNLOCK;
	return (err);
}

static int
vid_check_requirements(ACPI_HANDLE handle)
{
	ACPI_HANDLE h_dod, h_dos;
	ACPI_OBJECT_TYPE t_dos;

	ACPI_ASSERTLOCK;

	/* check for _DOD, _DOS methods */
	return (ACPI_SUCCESS(AcpiGetHandle(handle, "_DOD", &h_dod))
	    && ACPI_SUCCESS(AcpiGetHandle(handle, "_DOS", &h_dos))
	    && ACPI_SUCCESS(AcpiGetType(h_dos, &t_dos))
	    && t_dos == ACPI_TYPE_METHOD);
}

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

	ACPI_ASSERTLOCK;

	status = acpi_SetInteger(handle, "_DOS", policy);
	if (ACPI_FAILURE(status))
		printf("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;
};

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

	argset = context;
	status = acpi_GetInteger(handle, "_ADR", &adr);
	if (ACPI_SUCCESS(status)) {
		for (i = 0; i < argset->dod_pkg->Package.Count; i++) {
			tmp = &argset->dod_pkg->Package.Elements[i];
			if (tmp != NULL && tmp->Type == ACPI_TYPE_INTEGER &&
			    (tmp->Integer.Value & DOD_DEVID_MASK) == adr) {
				argset->callback(handle, tmp->Integer.Value,
						 argset->context);
				(**(int**)retp)++;
			}
		}
	}

	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;
	int num = 0;
	void *pnum;
	struct enum_callback_arg argset;

	ACPI_ASSERTLOCK;
	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)
			printf("can't evaluate %s._DOD - %s\n",
			       acpi_name(handle), AcpiFormatException(status));
		num = -1;
		goto out;
	}
	res = (ACPI_OBJECT *)dod_buf.Pointer;
	if (res == NULL || res->Type != ACPI_TYPE_PACKAGE) {
		printf("evaluation of %s._DOD makes no sense\n",
		       acpi_name(handle));
		num = -1;
		goto out;
	}
	if (callback == NULL) {
		num = res->Package.Count;
		goto out;
	}
	argset.callback = callback;
	argset.context  = context;
	argset.dod_pkg  = res;
	pnum = &num;
	status = AcpiWalkNamespace(ACPI_TYPE_DEVICE, handle, 1,
				   vid_enum_outputs_subr, &argset,
				   &pnum);
	if (ACPI_FAILURE(status))
		printf("failed walking down %s - %s\n",
		       acpi_name(handle), AcpiFormatException(status));
out:
	if (dod_buf.Pointer != NULL)
		AcpiOsFree(dod_buf.Pointer);
	return (num);
}

static int
vo_query_brightness_levels(ACPI_HANDLE handle, int **levelp)
{
	ACPI_STATUS status;
	ACPI_BUFFER bcl_buf;
	ACPI_OBJECT *res, *tmp;
	int num = 0, i, n, *levels;

	ACPI_ASSERTLOCK;
	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)
			printf("can't evaluate %s._BCL - %s\n",
			       acpi_name(handle), AcpiFormatException(status));
		num = -1;
		goto out;
	}
	res = (ACPI_OBJECT *)bcl_buf.Pointer;
	if (res == NULL || res->Type != ACPI_TYPE_PACKAGE ||
	    res->Package.Count < 2) {
		printf("evaluation of %s._BCL makes no sense\n",
		       acpi_name(handle));
		num = -1;
		goto out;
	}
	num = res->Package.Count;
	if (levelp == NULL)
		goto out;
	levels = AcpiOsAllocate(num * sizeof *levels);
	if (levels == NULL) {
		num = -1;
		goto out;
	}
	for (i = 0, n = 0; i < num; i++) {
		tmp = &res->Package.Elements[i];
		if (tmp != NULL && tmp->Type == ACPI_TYPE_INTEGER)
			levels[n++] = tmp->Integer.Value;
	}
	if (n < 2) {
		num = -1;
		AcpiOsFree(levels);
	} else {
		num = n;
		*levelp = levels;
	}
out:
	if (bcl_buf.Pointer != NULL)
		AcpiOsFree(bcl_buf.Pointer);

	return (num);
}

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

	ACPI_ASSERTLOCK;

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

static UINT32
vo_get_device_status(ACPI_HANDLE handle)
{
	UINT32 dcs = 0;
	ACPI_STATUS status;

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

	return (dcs);
}

static UINT32
vo_query_graphics_state(ACPI_HANDLE handle)
{
	UINT32 dgs = 0;
	ACPI_STATUS status;

	ACPI_ASSERTLOCK;
	status = acpi_GetInteger(handle, "_DGS", &dgs);
	if (ACPI_FAILURE(status))
		printf("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_ASSERTLOCK;

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