==== //depot/projects/power/sys/dev/acpica/acpi_video.c#2 - /home/john/work/p4/power/sys/dev/acpica/acpi_video.c ====
@@ -1,5 +1,6 @@
 /*-
  * Copyright (c) 2002-2003 Taku YAMAMOTO <taku@cent.saitama-u.ac.jp>
+ * Copyright (c) 2004 Benjamin Close <Benjamin.Close@clearchain.com>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -34,10 +35,33 @@
 #include <sys/power.h>
 #include <sys/queue.h>
 #include <sys/sysctl.h>
+#ifdef __i386__
+#include <machine/vm86.h>
+#endif
 
 #include "acpi.h"
 #include <dev/acpica/acpivar.h>
 
+#ifdef __i386__
+#define USE_DPMS
+
+/*
+ * VESA DPMS States 
+ */
+#define DPMS_ON		0x00
+#define DPMS_STANDBY	0x01
+#define DPMS_SUSPEND	0x02
+#define DPMS_OFF	0x04
+#define DPMS_REDUCEDON	0x08
+
+#define	VBE_DPMS_FUNCTION	0x4F10
+#define	VBE_DPMS_GET_SUPPORTED_STATES 0x00
+#define	VBE_DPMS_GET_STATE	0x02
+#define	VBE_DPMS_SET_STATE	0x01
+#define VBE_MAJORVERSION_MASK	0x0F
+#define VBE_MINORVERSION_MASK	0xF0
+#endif
+
 /* ACPI video extension driver. */
 struct acpi_video_output {
 	ACPI_HANDLE	handle;
@@ -63,6 +87,10 @@
 	ACPI_HANDLE		handle;
 	STAILQ_HEAD(, acpi_video_output) vid_outputs;
 	eventhandler_tag	vid_pwr_evh;
+#ifdef USE_DPMS
+	int			vid_dpms_supported_states;
+	int			vid_dpms_initial_state;
+#endif
 };
 
 /* interfaces */
@@ -71,6 +99,8 @@
 static int	acpi_video_attach(device_t);
 static int	acpi_video_detach(device_t);
 static int	acpi_video_shutdown(device_t);
+static int	acpi_video_suspend(device_t);
+static int	acpi_video_resume(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 *);
@@ -94,6 +124,11 @@
 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);
+#ifdef USE_DPMS
+static int	dpms_get_supported_states(int *);
+static int	dpms_get_current_state(int *);
+static int	dpms_set_state(int);
+#endif
 
 /* events */
 #define VID_NOTIFY_SWITCHED	0x80
@@ -141,6 +176,8 @@
 	DEVMETHOD(device_attach, acpi_video_attach),
 	DEVMETHOD(device_detach, acpi_video_detach),
 	DEVMETHOD(device_shutdown, acpi_video_shutdown),
+	DEVMETHOD(device_resume, acpi_video_resume),
+	DEVMETHOD(device_suspend, acpi_video_suspend),
 	{ 0, 0 }
 };
 
@@ -242,6 +279,13 @@
 	ACPI_UNLOCK;
 	acpi_video_power_profile(sc);
 
+#ifdef USE_DPMS
+	if (dpms_get_supported_states(&sc->vid_dpms_supported_states) == 0)
+		dpms_get_current_state(&sc->vid_dpms_initial_state);
+	else
+		sc->vid_dpms_supported_states = -1;
+#endif
+	
 	return (0);
 }
 
@@ -283,6 +327,32 @@
 	return (0);
 }
 
+static int
+acpi_video_suspend(device_t dev)
+{
+	struct acpi_video_softc *sc;
+
+	sc = device_get_softc(dev);
+#ifdef USE_DPMS
+	if (sc->vid_dpms_supported_states != -1)
+		dpms_set_state(DPMS_OFF);
+#endif
+	return (0);
+}
+
+static int
+acpi_video_resume(device_t dev)
+{
+	struct acpi_video_softc *sc;
+
+	sc = device_get_softc(dev);
+#ifdef USE_DPMS
+	if (sc->vid_dpms_supported_states != -1)
+		dpms_set_state(sc->vid_dpms_initial_state);
+#endif
+	return (0);
+}
+
 static void
 acpi_video_notify_handler(ACPI_HANDLE handle __unused, UINT32 notify, void *context)
 {
@@ -929,3 +999,49 @@
 		printf("can't evaluate %s._DSS - %s\n",
 		       acpi_name(handle), AcpiFormatException(status));
 }
+
+#ifdef USE_DPMS
+/* XXX: Requires VM86 support in the kernel. */
+static int
+dpms_call_bios(int subfunction, int *bh)
+{
+	struct vm86frame vmf;
+	int error;
+
+	bzero(&vmf, sizeof(vmf));
+	vmf.vmf_ax = VBE_DPMS_FUNCTION;
+	vmf.vmf_bl = subfunction;
+	vmf.vmf_bh = *bh;
+	vmf.vmf_es = 0;
+	vmf.vmf_di = 0;
+	error = vm86_intcall(0x10, &vmf);
+	if (error == 0 && (vmf.vmf_eax & 0xffff) != 0x004f)
+		error = ENXIO;
+	if (error == 0)
+		*bh = vmf.vmf_bh;
+	return (error);
+}
+
+static int
+dpms_get_supported_states(int *states)
+{
+
+	*states = 0;
+	return (dpms_call_bios(VBE_DPMS_GET_SUPPORTED_STATES, states));
+}
+
+static int
+dpms_get_current_state(int *state)
+{
+
+	*state = 0;
+	return (dpms_call_bios(VBE_DPMS_GET_STATE, state));
+}
+
+static int
+dpms_set_state(int state)
+{
+
+	return (dpms_call_bios(VBE_DPMS_SET_STATE, &state));
+}
+#endif