drivers/acpi/video_detect.c - arm/linux - Git at Google

 /*
  *  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:
  * After PCI devices are glued with ACPI devices
  * acpi_get_pci_dev() 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 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-laptop,
  * sony_acpi,... can take care about backlight brightness.
  *
  * 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/export.h>
 #include <linux/acpi.h>
 #include <linux/dmi.h>
 #include <linux/module.h>
 #include <linux/pci.h>

 ACPI_MODULE_NAME("video");
 #define _COMPONENT		ACPI_VIDEO_COMPONENT

 static long acpi_video_support;
 static bool acpi_video_caps_checked;

 static void acpi_video_parse_cmdline(void)
 {
 	if (!strcmp("vendor", acpi_video_backlight_string))
 		acpi_video_support |= ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
 	if (!strcmp("video", acpi_video_backlight_string))
 		acpi_video_support |= ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO;
 }

 static acpi_status
 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
 {
 	long *cap = context;
 	struct pci_dev *dev;
 	struct acpi_device *acpi_dev;

 	static 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_pci_dev(handle);
 		if (!dev)
 			return AE_OK;
 		pci_dev_put(dev);
 		*cap |= acpi_is_video_device(handle);
 	}
 	return AE_OK;
 }

 /* Force to use vendor driver when the ACPI device is known to be
  * buggy */
 static int video_detect_force_vendor(const struct dmi_system_id *d)
 {
 	acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
 	return 0;
 }

 static const struct dmi_system_id video_detect_dmi_table[] = {
 	/* On Samsung X360, the BIOS will set a flag (VDRV) if generic
 	 * ACPI backlight device is used. This flag will definitively break
 	 * the backlight interface (even the vendor interface) untill next
 	 * reboot. It's why we should prevent video.ko from being used here
 	 * and we can't rely on a later call to acpi_video_unregister().
 	 */
 	{
 	 .callback = video_detect_force_vendor,
 	 .ident = "X360",
 	 .matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
 		DMI_MATCH(DMI_BOARD_NAME, "X360"),
 		},
 	},
 	{
 	.callback = video_detect_force_vendor,
 	.ident = "Asus UL30VT",
 	.matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
 		},
 	},
 	{
 	.callback = video_detect_force_vendor,
 	.ident = "Asus UL30A",
 	.matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
 		},
 	},
 	{
 	.callback = video_detect_force_vendor,
 	.ident = "Dell Inspiron 5737",
 	.matches = {
 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 		DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 5737"),
 		},
 	},
 	{ },
 };

 /*
  * 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
  * summarized and returned. This is cached and done only once.
  */
 static 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, NULL,
 				    &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_BACKLIGHT_DMI_VENDOR;
 		 *}
 		 */

 		dmi_check_system(video_detect_dmi_table);
 	} 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, NULL,
 				    &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;
 }

 static void acpi_video_caps_check(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_parse_cmdline();
 		acpi_video_get_capabilities(NULL);
 	}
 }

 /* Promote the vendor interface instead of the generic video module.
  * This function allow DMI blacklists to be implemented by externals
  * platform drivers instead of putting a big blacklist in video_detect.c
  * After calling this function you will probably want to call
  * acpi_video_unregister() to make sure the video module is not loaded
  */
 void acpi_video_dmi_promote_vendor(void)
 {
 	acpi_video_caps_check();
 	acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
 }
 EXPORT_SYMBOL(acpi_video_dmi_promote_vendor);

 /* Returns true if video.ko can do backlight switching */
 int acpi_video_backlight_support(void)
 {
 	acpi_video_caps_check();

 	/* 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);
	/*
	* 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:
	* After PCI devices are glued with ACPI devices
	* acpi_get_pci_dev() 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 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-laptop,
	* sony_acpi,... can take care about backlight brightness.
	*
	* 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/export.h>
	#include <linux/acpi.h>
	#include <linux/dmi.h>
	#include <linux/module.h>
	#include <linux/pci.h>

	ACPI_MODULE_NAME("video");
	#define _COMPONENT ACPI_VIDEO_COMPONENT

	static long acpi_video_support;
	static bool acpi_video_caps_checked;

	static void acpi_video_parse_cmdline(void)
	{
	if (!strcmp("vendor", acpi_video_backlight_string))
	acpi_video_support \|= ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
	if (!strcmp("video", acpi_video_backlight_string))
	acpi_video_support \|= ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO;
	}

	static acpi_status
	find_video(acpi_handle handle, u32 lvl, void context, void *rv)
	{
	long *cap = context;
	struct pci_dev *dev;
	struct acpi_device *acpi_dev;

	static 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_pci_dev(handle);
	if (!dev)
	return AE_OK;
	pci_dev_put(dev);
	*cap \|= acpi_is_video_device(handle);
	}
	return AE_OK;
	}

	/* Force to use vendor driver when the ACPI device is known to be
	* buggy */
	static int video_detect_force_vendor(const struct dmi_system_id *d)
	{
	acpi_video_support \|= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
	return 0;
	}

	static const struct dmi_system_id video_detect_dmi_table[] = {
	/* On Samsung X360, the BIOS will set a flag (VDRV) if generic
	* ACPI backlight device is used. This flag will definitively break
	* the backlight interface (even the vendor interface) untill next
	* reboot. It's why we should prevent video.ko from being used here
	* and we can't rely on a later call to acpi_video_unregister().
	*/
	{
	.callback = video_detect_force_vendor,
	.ident = "X360",
	.matches = {
	DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
	DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
	DMI_MATCH(DMI_BOARD_NAME, "X360"),
	},
	},
	{
	.callback = video_detect_force_vendor,
	.ident = "Asus UL30VT",
	.matches = {
	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
	DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
	},
	},
	{
	.callback = video_detect_force_vendor,
	.ident = "Asus UL30A",
	.matches = {
	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
	DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
	},
	},
	{
	.callback = video_detect_force_vendor,
	.ident = "Dell Inspiron 5737",
	.matches = {
	DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
	DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 5737"),
	},
	},
	{ },
	};

	/*
	* 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
	* summarized and returned. This is cached and done only once.
	*/
	static 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, NULL,
	&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_BACKLIGHT_DMI_VENDOR;
	*}
	*/

	dmi_check_system(video_detect_dmi_table);
	} 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, NULL,
	&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;
	}

	static void acpi_video_caps_check(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_parse_cmdline();
	acpi_video_get_capabilities(NULL);
	}
	}

	/* Promote the vendor interface instead of the generic video module.
	* This function allow DMI blacklists to be implemented by externals
	* platform drivers instead of putting a big blacklist in video_detect.c
	* After calling this function you will probably want to call
	* acpi_video_unregister() to make sure the video module is not loaded
	*/
	void acpi_video_dmi_promote_vendor(void)
	{
	acpi_video_caps_check();
	acpi_video_support \|= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
	}
	EXPORT_SYMBOL(acpi_video_dmi_promote_vendor);

	/* Returns true if video.ko can do backlight switching */
	int acpi_video_backlight_support(void)
	{
	acpi_video_caps_check();

	/* 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);