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/*
* Copyright (C) 2015 Red Hat Inc.
* Hans de Goede <hdegoede@redhat.com>
* 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
*
* 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.
*
* Backlight drivers can use acpi_video_get_backlight_type() to determine which
* driver should handle the backlight. RAW/GPU-driver backlight drivers must
* use the acpi_video_backlight_use_native() helper for this.
*
* If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
* this file will not be compiled and acpi_video_get_backlight_type() will
* always return acpi_backlight_vendor.
*/
#include <linux/export.h>
#include <linux/acpi.h>
#include <linux/apple-gmux.h>
#include <linux/backlight.h>
#include <linux/dmi.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/platform_data/x86/nvidia-wmi-ec-backlight.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <acpi/video.h>
static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef;
static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef;
static void acpi_video_parse_cmdline(void)
{
if (!strcmp("vendor", acpi_video_backlight_string))
acpi_backlight_cmdline = acpi_backlight_vendor;
if (!strcmp("video", acpi_video_backlight_string))
acpi_backlight_cmdline = acpi_backlight_video;
if (!strcmp("native", acpi_video_backlight_string))
acpi_backlight_cmdline = acpi_backlight_native;
if (!strcmp("none", acpi_video_backlight_string))
acpi_backlight_cmdline = acpi_backlight_none;
}
static acpi_status
find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
{
struct acpi_device *acpi_dev = acpi_fetch_acpi_dev(handle);
long *cap = context;
struct pci_dev *dev;
static const struct acpi_device_id video_ids[] = {
{ACPI_VIDEO_HID, 0},
{"", 0},
};
if (acpi_dev && !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;
}
/* This depends on ACPI_WMI which is X86 only */
#ifdef CONFIG_X86
static bool nvidia_wmi_ec_supported(void)
{
struct wmi_brightness_args args = {
.mode = WMI_BRIGHTNESS_MODE_GET,
.val = 0,
.ret = 0,
};
struct acpi_buffer buf = { (acpi_size)sizeof(args), &args };
acpi_status status;
status = wmi_evaluate_method(WMI_BRIGHTNESS_GUID, 0,
WMI_BRIGHTNESS_METHOD_SOURCE, &buf, &buf);
if (ACPI_FAILURE(status))
return false;
/*
* If brightness is handled by the EC then nvidia-wmi-ec-backlight
* should be used, else the GPU driver(s) should be used.
*/
return args.ret == WMI_BRIGHTNESS_SOURCE_EC;
}
#else
static bool nvidia_wmi_ec_supported(void)
{
return false;
}
#endif
/* 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_backlight_dmi = acpi_backlight_vendor;
return 0;
}
static int video_detect_force_video(const struct dmi_system_id *d)
{
acpi_backlight_dmi = acpi_backlight_video;
return 0;
}
static int video_detect_force_native(const struct dmi_system_id *d)
{
acpi_backlight_dmi = acpi_backlight_native;
return 0;
}
static int video_detect_force_none(const struct dmi_system_id *d)
{
acpi_backlight_dmi = acpi_backlight_none;
return 0;
}
static const struct dmi_system_id video_detect_dmi_table[] = {
{
/* https://bugzilla.redhat.com/show_bug.cgi?id=1128309 */
.callback = video_detect_force_vendor,
/* Acer KAV80 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
DMI_MATCH(DMI_PRODUCT_NAME, "KAV80"),
},
},
{
.callback = video_detect_force_vendor,
/* Asus UL30VT */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
},
},
{
.callback = video_detect_force_vendor,
/* Asus UL30A */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
},
},
{
.callback = video_detect_force_vendor,
/* Asus X55U */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "X55U"),
},
},
{
.callback = video_detect_force_vendor,
/* Asus X101CH */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "X101CH"),
},
},
{
.callback = video_detect_force_vendor,
/* Asus X401U */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "X401U"),
},
},
{
.callback = video_detect_force_vendor,
/* Asus X501U */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "X501U"),
},
},
{
.callback = video_detect_force_vendor,
/* Asus 1015CX */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "1015CX"),
},
},
{
.callback = video_detect_force_vendor,
/* GIGABYTE GB-BXBT-2807 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
DMI_MATCH(DMI_PRODUCT_NAME, "GB-BXBT-2807"),
},
},
{
.callback = video_detect_force_vendor,
/* Samsung N150/N210/N220 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "N150/N210/N220"),
DMI_MATCH(DMI_BOARD_NAME, "N150/N210/N220"),
},
},
{
.callback = video_detect_force_vendor,
/* Samsung NF110/NF210/NF310 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "NF110/NF210/NF310"),
DMI_MATCH(DMI_BOARD_NAME, "NF110/NF210/NF310"),
},
},
{
.callback = video_detect_force_vendor,
/* Samsung NC210 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "NC210/NC110"),
DMI_MATCH(DMI_BOARD_NAME, "NC210/NC110"),
},
},
{
.callback = video_detect_force_vendor,
/* Sony VPCEH3U1E */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
DMI_MATCH(DMI_PRODUCT_NAME, "VPCEH3U1E"),
},
},
{
.callback = video_detect_force_vendor,
/* Xiaomi Mi Pad 2 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Xiaomi Inc"),
DMI_MATCH(DMI_PRODUCT_NAME, "Mipad2"),
},
},
/*
* Toshiba models with Transflective display, these need to use
* the toshiba_acpi vendor driver for proper Transflective handling.
*/
{
.callback = video_detect_force_vendor,
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R500"),
},
},
{
.callback = video_detect_force_vendor,
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R600"),
},
},
/*
* These models have a working acpi_video backlight control, and using
* native backlight causes a regression where backlight does not work
* when userspace is not handling brightness key events. Disable
* native_backlight on these to fix this:
* https://bugzilla.kernel.org/show_bug.cgi?id=81691
*/
{
.callback = video_detect_force_video,
/* ThinkPad T420 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
},
},
{
.callback = video_detect_force_video,
/* ThinkPad T520 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
},
},
{
.callback = video_detect_force_video,
/* ThinkPad X201s */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
},
},
{
.callback = video_detect_force_video,
/* ThinkPad X201T */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201T"),
},
},
/* The native backlight controls do not work on some older machines */
{
/* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
.callback = video_detect_force_video,
/* HP ENVY 15 Notebook */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
},
},
{
.callback = video_detect_force_video,
/* SAMSUNG 870Z5E/880Z5E/680Z5E */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
},
},
{
.callback = video_detect_force_video,
/* SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME,
"370R4E/370R4V/370R5E/3570RE/370R5V"),
},
},
{
/* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
.callback = video_detect_force_video,
/* SAMSUNG 3570R/370R/470R/450R/510R/4450RV */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME,
"3570R/370R/470R/450R/510R/4450RV"),
},
},
{
/* https://bugzilla.redhat.com/show_bug.cgi?id=1557060 */
.callback = video_detect_force_video,
/* SAMSUNG 670Z5E */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "670Z5E"),
},
},
{
/* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
.callback = video_detect_force_video,
/* SAMSUNG 730U3E/740U3E */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
},
},
{
/* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */
.callback = video_detect_force_video,
/* SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME,
"900X3C/900X3D/900X3E/900X4C/900X4D"),
},
},
{
/* https://bugzilla.redhat.com/show_bug.cgi?id=1272633 */
.callback = video_detect_force_video,
/* Dell XPS14 L421X */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
},
},
{
/* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
.callback = video_detect_force_video,
/* Dell XPS15 L521X */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
},
},
{
/* https://bugzilla.kernel.org/show_bug.cgi?id=108971 */
.callback = video_detect_force_video,
/* SAMSUNG 530U4E/540U4E */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "530U4E/540U4E"),
},
},
/* https://bugs.launchpad.net/bugs/1894667 */
{
.callback = video_detect_force_video,
/* HP 635 Notebook */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
DMI_MATCH(DMI_PRODUCT_NAME, "HP 635 Notebook PC"),
},
},
/* Non win8 machines which need native backlight nevertheless */
{
/* https://bugzilla.redhat.com/show_bug.cgi?id=1201530 */
.callback = video_detect_force_native,
/* Lenovo Ideapad S405 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_BOARD_NAME, "Lenovo IdeaPad S405"),
},
},
{
/* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
.callback = video_detect_force_native,
/* Lenovo Ideapad Z570 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_NAME, "102434U"),
},
},
{
.callback = video_detect_force_native,
/* Lenovo E41-25 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_NAME, "81FS"),
},
},
{
.callback = video_detect_force_native,
/* Lenovo E41-45 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
DMI_MATCH(DMI_PRODUCT_NAME, "82BK"),
},
},
{
/* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
.callback = video_detect_force_native,
/* Apple MacBook Pro 12,1 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"),
},
},
{
.callback = video_detect_force_native,
/* Dell Inspiron N4010 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron N4010"),
},
},
{
.callback = video_detect_force_native,
/* Dell Vostro V131 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
},
},
{
/* https://bugzilla.redhat.com/show_bug.cgi?id=1123661 */
.callback = video_detect_force_native,
/* Dell XPS 17 L702X */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L702X"),
},
},
{
.callback = video_detect_force_native,
/* Dell Precision 7510 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
},
},
{
.callback = video_detect_force_native,
/* Acer Aspire 5738z */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5738"),
DMI_MATCH(DMI_BOARD_NAME, "JV50"),
},
},
{
/* https://bugzilla.redhat.com/show_bug.cgi?id=1012674 */
.callback = video_detect_force_native,
/* Acer Aspire 5741 */
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5741"),
},
},
{
/* https://bugzilla.kernel.org/show_bug.cgi?id=42993 */
.callback = video_detect_force_native,
/* Acer Aspire 5750 */
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5750"),
},
},
{
/* https://bugzilla.kernel.org/show_bug.cgi?id=42833 */
.callback = video_detect_force_native,
/* Acer Extensa 5235 */
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
DMI_MATCH(DMI_PRODUCT_NAME, "Extensa 5235"),
},
},
{
.callback = video_detect_force_native,
/* Acer TravelMate 4750 */
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 4750"),
},
},
{
/* https://bugzilla.kernel.org/show_bug.cgi?id=207835 */
.callback = video_detect_force_native,
/* Acer TravelMate 5735Z */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5735Z"),
DMI_MATCH(DMI_BOARD_NAME, "BA51_MV"),
},
},
{
/* https://bugzilla.kernel.org/show_bug.cgi?id=36322 */
.callback = video_detect_force_native,
/* Acer TravelMate 5760 */
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5760"),
},
},
{
.callback = video_detect_force_native,
/* ASUSTeK COMPUTER INC. GA401 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "GA401"),
},
},
{
.callback = video_detect_force_native,
/* ASUSTeK COMPUTER INC. GA502 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "GA502"),
},
},
{
.callback = video_detect_force_native,
/* ASUSTeK COMPUTER INC. GA503 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "GA503"),
},
},
{
.callback = video_detect_force_native,
/* Asus UX303UB */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
DMI_MATCH(DMI_PRODUCT_NAME, "UX303UB"),
},
},
{
.callback = video_detect_force_native,
/* Samsung N150P */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "N150P"),
DMI_MATCH(DMI_BOARD_NAME, "N150P"),
},
},
{
.callback = video_detect_force_native,
/* Samsung N145P/N250P/N260P */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "N145P/N250P/N260P"),
DMI_MATCH(DMI_BOARD_NAME, "N145P/N250P/N260P"),
},
},
{
.callback = video_detect_force_native,
/* Samsung N250P */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
DMI_MATCH(DMI_PRODUCT_NAME, "N250P"),
DMI_MATCH(DMI_BOARD_NAME, "N250P"),
},
},
/*
* These Toshibas have a broken acpi-video interface for brightness
* control. They also have an issue where the panel is off after
* suspend until a special firmware call is made to turn it back
* on. This is handled by the toshiba_acpi kernel module, so that
* module must be enabled for these models to work correctly.
*/
{
/* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
.callback = video_detect_force_native,
/* Toshiba Portégé R700 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
},
},
{
/* Portégé: https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
/* Satellite: https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
.callback = video_detect_force_native,
/* Toshiba Satellite/Portégé R830 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
DMI_MATCH(DMI_PRODUCT_NAME, "R830"),
},
},
{
.callback = video_detect_force_native,
/* Toshiba Satellite/Portégé Z830 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
DMI_MATCH(DMI_PRODUCT_NAME, "Z830"),
},
},
/*
* Desktops which falsely report a backlight and which our heuristics
* for this do not catch.
*/
{
.callback = video_detect_force_none,
/* Dell OptiPlex 9020M */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 9020M"),
},
},
{
.callback = video_detect_force_none,
/* MSI MS-7721 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "MSI"),
DMI_MATCH(DMI_PRODUCT_NAME, "MS-7721"),
},
},
{ },
};
/*
* Determine which type of backlight interface to use on this system,
* First check cmdline, then dmi quirks, then do autodetect.
*/
static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
{
static DEFINE_MUTEX(init_mutex);
static bool nvidia_wmi_ec_present;
static bool native_available;
static bool init_done;
static long video_caps;
/* Parse cmdline, dmi and acpi only once */
mutex_lock(&init_mutex);
if (!init_done) {
acpi_video_parse_cmdline();
dmi_check_system(video_detect_dmi_table);
acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX, find_video, NULL,
&video_caps, NULL);
nvidia_wmi_ec_present = nvidia_wmi_ec_supported();
init_done = true;
}
if (native)
native_available = true;
mutex_unlock(&init_mutex);
/*
* The below heuristics / detection steps are in order of descending
* presedence. The commandline takes presedence over anything else.
*/
if (acpi_backlight_cmdline != acpi_backlight_undef)
return acpi_backlight_cmdline;
/* DMI quirks override any autodetection. */
if (acpi_backlight_dmi != acpi_backlight_undef)
return acpi_backlight_dmi;
/* Special cases such as nvidia_wmi_ec and apple gmux. */
if (nvidia_wmi_ec_present)
return acpi_backlight_nvidia_wmi_ec;
if (apple_gmux_present())
return acpi_backlight_apple_gmux;
/* On systems with ACPI video use either native or ACPI video. */
if (video_caps & ACPI_VIDEO_BACKLIGHT) {
/*
* Windows 8 and newer no longer use the ACPI video interface,
* so it often does not work. If the ACPI tables are written
* for win8 and native brightness ctl is available, use that.
*
* The native check deliberately is inside the if acpi-video
* block on older devices without acpi-video support native
* is usually not the best choice.
*/
if (acpi_osi_is_win8() && native_available)
return acpi_backlight_native;
else
return acpi_backlight_video;
}
/* No ACPI video (old hw), use vendor specific fw methods. */
return acpi_backlight_vendor;
}
enum acpi_backlight_type acpi_video_get_backlight_type(void)
{
return __acpi_video_get_backlight_type(false);
}
EXPORT_SYMBOL(acpi_video_get_backlight_type);
bool acpi_video_backlight_use_native(void)
{
return __acpi_video_get_backlight_type(true) == acpi_backlight_native;
}
EXPORT_SYMBOL(acpi_video_backlight_use_native);