[mirror_ubuntu-artful-kernel.git] / drivers / acpi / video_detect.c

/*
 *  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 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.
 *
 * 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/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 "No _BQC method, "
				"cannot determine initial brightness\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, NULL,
				    &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, 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;
		 *}
		 */
	} 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;
}
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);

/*
 * Use acpi_backlight=vendor/video to force that backlight 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_BACKLIGHT_FORCE_VIDEO;
	}
	return 1;
}
__setup("acpi_backlight=", acpi_backlight);
Commit	Line	Data
c3d6de69 TR	1	/*
	2	* Copyright (C) 2008 SuSE Linux Products GmbH
	3	* Thomas Renninger <trenn@suse.de>
	4	*
	5	* May be copied or modified under the terms of the GNU General Public License
	6	*
	7	* video_detect.c:
	8	* Provides acpi_is_video_device() for early scanning of ACPI devices in scan.c
	9	* There a Linux specific (Spec does not provide a HID for video devices) is
94e2bd68	10	* assigned
c3d6de69 TR	11	*
c3d6de69 TR	12	* After PCI devices are glued with ACPI devices
1e4cffe7	13	* acpi_get_pci_dev() can be called to identify ACPI graphics
c3d6de69 TR	14	* devices for which a real graphics card is plugged in
	15	*
	16	* Now acpi_video_get_capabilities() can be called to check which
	17	* capabilities the graphics cards plugged in support. The check for general
	18	* video capabilities will be triggered by the first caller of
	19	* acpi_video_get_capabilities(NULL); which will happen when the first
677bd810	20	* backlight switching supporting driver calls:
c3d6de69 TR	21	* acpi_video_backlight_support();
	22	*
	23	* Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B)
	24	* are available, video.ko should be used to handle the device.
	25	*
	26	* Otherwise vendor specific drivers like thinkpad_acpi, asus_acpi,
677bd810	27	* sony_acpi,... can take care about backlight brightness.
c3d6de69 TR	28	*
	29	* If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
	30	* this file will not be compiled, acpi_video_get_capabilities() and
	31	* acpi_video_backlight_support() will always return 0 and vendor specific
	32	* drivers always can handle backlight.
	33	*
	34	*/
	35
214f2c90	36	#include <linux/export.h>
c3d6de69 TR	37	#include <linux/acpi.h>
c3d6de69 TR	38	#include <linux/dmi.h>
1e4cffe7	39	#include <linux/pci.h>
c3d6de69	40
a192a958 LB	41	#define PREFIX "ACPI: "
a192a958 LB	42
c3d6de69	43	ACPI_MODULE_NAME("video");
c3d6de69 TR	44	#define _COMPONENT ACPI_VIDEO_COMPONENT
	45
	46	static long acpi_video_support;
	47	static bool acpi_video_caps_checked;
	48
	49	static acpi_status
	50	acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
	51	void **retyurn_value)
	52	{
	53	long *cap = context;
	54	acpi_handle h_dummy;
	55
	56	if (ACPI_SUCCESS(acpi_get_handle(handle, "_BCM", &h_dummy)) &&
	57	ACPI_SUCCESS(acpi_get_handle(handle, "_BCL", &h_dummy))) {
	58	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
	59	"support\n"));
	60	*cap \|= ACPI_VIDEO_BACKLIGHT;
98758faf	61	if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy)))
e9f74c48 ZR	62	printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
e9f74c48 ZR	63	"cannot determine initial brightness\n");
c3d6de69 TR	64	/* We have backlight support, no need to scan further */
	65	return AE_CTRL_TERMINATE;
	66	}
	67	return 0;
	68	}
	69
	70	/* Returns true if the device is a video device which can be handled by
	71	* video.ko.
	72	* The device will get a Linux specific CID added in scan.c to
	73	* identify the device as an ACPI graphics device
	74	* Be aware that the graphics device may not be physically present
	75	* Use acpi_video_get_capabilities() to detect general ACPI video
	76	* capabilities of present cards
	77	*/
	78	long acpi_is_video_device(struct acpi_device *device)
	79	{
	80	acpi_handle h_dummy;
	81	long video_caps = 0;
	82
	83	if (!device)
	84	return 0;
	85
ed764e7c MK	86	/* Is this device able to support video switching ? */
	87	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) \|\|
	88	ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy)))
	89	video_caps \|= ACPI_VIDEO_OUTPUT_SWITCHING;
	90
94e2bd68	91	/* Is this device able to retrieve a video ROM ? */
c3d6de69 TR	92	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))
	93	video_caps \|= ACPI_VIDEO_ROM_AVAILABLE;
	94
94e2bd68	95	/* Is this device able to configure which video head to be POSTed ? */
c3d6de69 TR	96	if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) &&
	97	ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) &&
	98	ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy)))
	99	video_caps \|= ACPI_VIDEO_DEVICE_POSTING;
	100
	101	/* Only check for backlight functionality if one of the above hit. */
	102	if (video_caps)
	103	acpi_walk_namespace(ACPI_TYPE_DEVICE, device->handle,
2263576c	104	ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
c3d6de69 TR	105	&video_caps, NULL);
	106
	107	return video_caps;
	108	}
	109	EXPORT_SYMBOL(acpi_is_video_device);
	110
	111	static acpi_status
	112	find_video(acpi_handle handle, u32 lvl, void context, void *rv)
	113	{
	114	long *cap = context;
1e4cffe7	115	struct pci_dev *dev;
c3d6de69 TR	116	struct acpi_device *acpi_dev;
	117
	118	const struct acpi_device_id video_ids[] = {
	119	{ACPI_VIDEO_HID, 0},
	120	{"", 0},
	121	};
	122	if (acpi_bus_get_device(handle, &acpi_dev))
	123	return AE_OK;
	124
	125	if (!acpi_match_device_ids(acpi_dev, video_ids)) {
1e4cffe7	126	dev = acpi_get_pci_dev(handle);
c3d6de69 TR	127	if (!dev)
c3d6de69 TR	128	return AE_OK;
1e4cffe7	129	pci_dev_put(dev);
c3d6de69 TR	130	*cap \|= acpi_is_video_device(acpi_dev);
	131	}
	132	return AE_OK;
	133	}
	134
	135	/*
	136	* Returns the video capabilities of a specific ACPI graphics device
	137	*
	138	* if NULL is passed as argument all ACPI devices are enumerated and
	139	* all graphics capabilities of physically present devices are
94e2bd68	140	* summarized and returned. This is cached and done only once.
c3d6de69 TR	141	*/
	142	long acpi_video_get_capabilities(acpi_handle graphics_handle)
	143	{
	144	long caps = 0;
	145	struct acpi_device *tmp_dev;
	146	acpi_status status;
	147
	148	if (acpi_video_caps_checked && graphics_handle == NULL)
	149	return acpi_video_support;
	150
	151	if (!graphics_handle) {
	152	/* Only do the global walk through all graphics devices once */
	153	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
2263576c	154	ACPI_UINT32_MAX, find_video, NULL,
c3d6de69 TR	155	&caps, NULL);
	156	/* There might be boot param flags set already... */
	157	acpi_video_support \|= caps;
	158	acpi_video_caps_checked = 1;
	159	/* Add blacklists here. Be careful to use the right DMI bits
	160	* to still be able to override logic via boot params, e.g.:
	161	*
	162	* if (dmi_name_in_vendors("XY")) {
	163	* acpi_video_support \|=
c3d6de69 TR	164	* ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
	165	*}
	166	*/
	167	} else {
	168	status = acpi_bus_get_device(graphics_handle, &tmp_dev);
	169	if (ACPI_FAILURE(status)) {
	170	ACPI_EXCEPTION((AE_INFO, status, "Invalid device"));
	171	return 0;
	172	}
	173	acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle,
2263576c	174	ACPI_UINT32_MAX, find_video, NULL,
c3d6de69 TR	175	&caps, NULL);
	176	}
	177	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n",
	178	graphics_handle ? caps : acpi_video_support,
	179	graphics_handle ? "on device " : "in general",
	180	graphics_handle ? acpi_device_bid(tmp_dev) : ""));
	181	return caps;
	182	}
	183	EXPORT_SYMBOL(acpi_video_get_capabilities);
	184
	185	/* Returns true if video.ko can do backlight switching */
	186	int acpi_video_backlight_support(void)
	187	{
	188	/*
	189	* We must check whether the ACPI graphics device is physically plugged
	190	* in. Therefore this must be called after binding PCI and ACPI devices
	191	*/
	192	if (!acpi_video_caps_checked)
	193	acpi_video_get_capabilities(NULL);
	194
	195	/* First check for boot param -> highest prio */
	196	if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)
	197	return 0;
	198	else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO)
	199	return 1;
	200
	201	/* Then check for DMI blacklist -> second highest prio */
	202	if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR)
	203	return 0;
	204	else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO)
	205	return 1;
	206
	207	/* Then go the default way */
	208	return acpi_video_support & ACPI_VIDEO_BACKLIGHT;
	209	}
	210	EXPORT_SYMBOL(acpi_video_backlight_support);
	211
	212	/*
677bd810 ZR	213	* Use acpi_backlight=vendor/video to force that backlight switching
677bd810 ZR	214	* is processed by vendor specific acpi drivers or video.ko driver.
c3d6de69	215	*/
8a383ef0	216	static int __init acpi_backlight(char *str)
c3d6de69 TR	217	{
	218	if (str == NULL \|\| *str == '\0')
	219	return 1;
	220	else {
	221	if (!strcmp("vendor", str))
	222	acpi_video_support \|=
	223	ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
	224	if (!strcmp("video", str))
	225	acpi_video_support \|=
eeb4bcb4	226	ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO;
c3d6de69 TR	227	}
	228	return 1;
	229	}
	230	__setup("acpi_backlight=", acpi_backlight);