drivers/acpi/video_detect.c - maze/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:
  * 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
  * assigned
  *
  * 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 (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>
 #include <linux/pci.h>

 #define PREFIX "ACPI: "

 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;
 		if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy)))
 			printk(KERN_WARNING FW_BUG PREFIX "ACPI brightness "
 					"control misses _BQC function\n");
 		/* 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;

 	/* Is 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;

 	/* Is 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;

 	/* Is 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 pci_dev *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_pci_dev(handle);
 		if (!dev)
 			return AE_OK;
 		pci_dev_put(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
  * summarized 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.
  */
 static 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);

 static 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);
	/*
	* 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
	* assigned
	*
	* 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 (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>
	#include <linux/pci.h>

	#define PREFIX "ACPI: "

	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;
	if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy)))
	printk(KERN_WARNING FW_BUG PREFIX "ACPI brightness "
	"control misses _BQC function\n");
	/* 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;

	/* Is 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;

	/* Is 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;

	/* Is 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 pci_dev *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_pci_dev(handle);
	if (!dev)
	return AE_OK;
	pci_dev_put(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
	* summarized 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.
	*/
	static 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);

	static 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);