linux/drivers/acpi/video_detect.c

/*
 *  Copyright (C) 2015       Red Hat Inc.
 *                           Hans de Goede <[email protected]>
 *  Copyright (C) 2008       SuSE Linux Products GmbH
 *                           Thomas Renninger <[email protected]>
 *
 *  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/pnp.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <acpi/video.h>

static enum acpi_backlight_type acpi_backlight_cmdline = …;
static enum acpi_backlight_type acpi_backlight_dmi = …;

static void acpi_video_parse_cmdline(void)
{ … }

static acpi_status
find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
{ … }

/* This depends on ACPI_WMI which is X86 only */
#ifdef CONFIG_X86
static bool nvidia_wmi_ec_supported(void)
{ … }
#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)
{ … }

static int video_detect_force_video(const struct dmi_system_id *d)
{ … }

static int video_detect_force_native(const struct dmi_system_id *d)
{ … }

static int video_detect_portege_r100(const struct dmi_system_id *d)
{ … }

static const struct dmi_system_id video_detect_dmi_table[] = …;

static bool google_cros_ec_present(void)
{ … }

/*
 * Windows 8 and newer no longer use the ACPI video interface, so it often
 * does not work. So on win8+ systems prefer native brightness control.
 * Chromebooks should always prefer native backlight control.
 */
static bool prefer_native_over_acpi_video(void)
{ … }

/*
 * Determine which type of backlight interface to use on this system,
 * First check cmdline, then dmi quirks, then do autodetect.
 */
enum acpi_backlight_type __acpi_video_get_backlight_type(bool native, bool *auto_detect)
{ … }
EXPORT_SYMBOL(…);