1 files changed, 267 insertions, 0 deletions
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
new file mode 100644
index 000000000000..f022eb6f5637
--- /dev/null
+++ b/drivers/acpi/video_detect.c
@@ -0,0 +1,267 @@
+/*
+ *  Copyright (C) 2008       SuSE Linux Products GmbH
+ *                           Thomas Renninger <trenn@suse.de>
+ *
+ *  May be copied or modified under the terms of the GNU General Public License
+ *
+ * video_detect.c:
+ * Provides acpi_is_video_device() for early scanning of ACPI devices in scan.c
+ * There a Linux specific (Spec does not provide a HID for video devices) is
+ * assinged
+ *
+ * After PCI devices are glued with ACPI devices
+ * acpi_get_physical_pci_device() can be called to identify ACPI graphics
+ * devices for which a real graphics card is plugged in
+ *
+ * Now acpi_video_get_capabilities() can be called to check which
+ * capabilities the graphics cards plugged in support. The check for general
+ * video capabilities will be triggered by the first caller of
+ * acpi_video_get_capabilities(NULL); which will happen when the first
+ * backlight (or display output) switching supporting driver calls:
+ * acpi_video_backlight_support();
+ *
+ * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B)
+ * are available, video.ko should be used to handle the device.
+ *
+ * Otherwise vendor specific drivers like thinkpad_acpi, asus_acpi,
+ * sony_acpi,... can take care about backlight brightness and display output
+ * switching.
+ *
+ * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
+ * this file will not be compiled, acpi_video_get_capabilities() and
+ * acpi_video_backlight_support() will always return 0 and vendor specific
+ * drivers always can handle backlight.
+ *
+ */
+
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+
+ACPI_MODULE_NAME("video");
+#define _COMPONENT		ACPI_VIDEO_COMPONENT
+
+static long acpi_video_support;
+static bool acpi_video_caps_checked;
+
+static acpi_status
+acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
+			  void **retyurn_value)
+{
+	long *cap = context;
+	acpi_handle h_dummy;
+
+	if (ACPI_SUCCESS(acpi_get_handle(handle, "_BCM", &h_dummy)) &&
+	    ACPI_SUCCESS(acpi_get_handle(handle, "_BCL", &h_dummy))) {
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
+				  "support\n"));
+		*cap |= ACPI_VIDEO_BACKLIGHT;
+		/* We have backlight support, no need to scan further */
+		return AE_CTRL_TERMINATE;
+	}
+	return 0;
+}
+
+/* Returns true if the device is a video device which can be handled by
+ * video.ko.
+ * The device will get a Linux specific CID added in scan.c to
+ * identify the device as an ACPI graphics device
+ * Be aware that the graphics device may not be physically present
+ * Use acpi_video_get_capabilities() to detect general ACPI video
+ * capabilities of present cards
+ */
+long acpi_is_video_device(struct acpi_device *device)
+{
+	acpi_handle h_dummy;
+	long video_caps = 0;
+
+	if (!device)
+		return 0;
+
+	/* Does this device able to support video switching ? */
+	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) &&
+	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy)))
+		video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
+
+	/* Does this device able to retrieve a video ROM ? */
+	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))
+		video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
+
+	/* Does this device able to configure which video head to be POSTed ? */
+	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) &&
+	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) &&
+	    ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy)))
+		video_caps |= ACPI_VIDEO_DEVICE_POSTING;
+
+	/* Only check for backlight functionality if one of the above hit. */
+	if (video_caps)
+		acpi_walk_namespace(ACPI_TYPE_DEVICE, device->handle,
+				    ACPI_UINT32_MAX, acpi_backlight_cap_match,
+				    &video_caps, NULL);
+
+	return video_caps;
+}
+EXPORT_SYMBOL(acpi_is_video_device);
+
+static acpi_status
+find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
+{
+	long *cap = context;
+	struct device *dev;
+	struct acpi_device *acpi_dev;
+
+	const struct acpi_device_id video_ids[] = {
+		{ACPI_VIDEO_HID, 0},
+		{"", 0},
+	};
+	if (acpi_bus_get_device(handle, &acpi_dev))
+		return AE_OK;
+
+	if (!acpi_match_device_ids(acpi_dev, video_ids)) {
+		dev = acpi_get_physical_pci_device(handle);
+		if (!dev)
+			return AE_OK;
+		put_device(dev);
+		*cap |= acpi_is_video_device(acpi_dev);
+	}
+	return AE_OK;
+}
+
+/*
+ * Returns the video capabilities of a specific ACPI graphics device
+ *
+ * if NULL is passed as argument all ACPI devices are enumerated and
+ * all graphics capabilities of physically present devices are
+ * summerized and returned. This is cached and done only once.
+ */
+long acpi_video_get_capabilities(acpi_handle graphics_handle)
+{
+	long caps = 0;
+	struct acpi_device *tmp_dev;
+	acpi_status status;
+
+	if (acpi_video_caps_checked && graphics_handle == NULL)
+		return acpi_video_support;
+
+	if (!graphics_handle) {
+		/* Only do the global walk through all graphics devices once */
+		acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+				    ACPI_UINT32_MAX, find_video,
+				    &caps, NULL);
+		/* There might be boot param flags set already... */
+		acpi_video_support |= caps;
+		acpi_video_caps_checked = 1;
+		/* Add blacklists here. Be careful to use the right *DMI* bits
+		 * to still be able to override logic via boot params, e.g.:
+		 *
+		 *   if (dmi_name_in_vendors("XY")) {
+		 *	acpi_video_support |=
+		 *		ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VENDOR;
+		 *	acpi_video_support |=
+		 *		ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
+		 *}
+		 */
+	} else {
+		status = acpi_bus_get_device(graphics_handle, &tmp_dev);
+		if (ACPI_FAILURE(status)) {
+			ACPI_EXCEPTION((AE_INFO, status, "Invalid device"));
+			return 0;
+		}
+		acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle,
+				    ACPI_UINT32_MAX, find_video,
+				    &caps, NULL);
+	}
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n",
+			  graphics_handle ? caps : acpi_video_support,
+			  graphics_handle ? "on device " : "in general",
+			  graphics_handle ? acpi_device_bid(tmp_dev) : ""));
+	return caps;
+}
+EXPORT_SYMBOL(acpi_video_get_capabilities);
+
+/* Returns true if video.ko can do backlight switching */
+int acpi_video_backlight_support(void)
+{
+	/*
+	 * We must check whether the ACPI graphics device is physically plugged
+	 * in. Therefore this must be called after binding PCI and ACPI devices
+	 */
+	if (!acpi_video_caps_checked)
+		acpi_video_get_capabilities(NULL);
+
+	/* First check for boot param -> highest prio */
+	if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)
+		return 0;
+	else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO)
+		return 1;
+
+	/* Then check for DMI blacklist -> second highest prio */
+	if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR)
+		return 0;
+	else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO)
+		return 1;
+
+	/* Then go the default way */
+	return acpi_video_support & ACPI_VIDEO_BACKLIGHT;
+}
+EXPORT_SYMBOL(acpi_video_backlight_support);
+
+/*
+ * Returns true if video.ko can do display output switching.
+ * This does not work well/at all with binary graphics drivers
+ * which disable system io ranges and do it on their own.
+ */
+int acpi_video_display_switch_support(void)
+{
+	if (!acpi_video_caps_checked)
+		acpi_video_get_capabilities(NULL);
+
+	if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VENDOR)
+		return 0;
+	else if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO)
+		return 1;
+
+	if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VENDOR)
+		return 0;
+	else if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VIDEO)
+		return 1;
+
+	return acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING;
+}
+EXPORT_SYMBOL(acpi_video_display_switch_support);
+
+/*
+ * Use acpi_display_output=vendor/video or acpi_backlight=vendor/video
+ * To force that backlight or display output switching is processed by vendor
+ * specific acpi drivers or video.ko driver.
+ */
+int __init acpi_backlight(char *str)
+{
+	if (str == NULL || *str == '\0')
+		return 1;
+	else {
+		if (!strcmp("vendor", str))
+			acpi_video_support |=
+				ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
+		if (!strcmp("video", str))
+			acpi_video_support |=
+				ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO;
+	}
+	return 1;
+}
+__setup("acpi_backlight=", acpi_backlight);
+
+int __init acpi_display_output(char *str)
+{
+	if (str == NULL || *str == '\0')
+		return 1;
+	else {
+		if (!strcmp("vendor", str))
+			acpi_video_support |=
+				ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VENDOR;
+		if (!strcmp("video", str))
+			acpi_video_support |=
+				ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO;
+	}
+	return 1;
+}
+__setup("acpi_display_output=", acpi_display_output);