linux/include/acpi/video.h
Hans de Goede 52304886ea ACPI: video: Add comment about acpi_video_backlight_use_native() usage
Add a comment explaining that acpi_video_backlight_use_native() MUST
only be used by GPU drivers and that it must NOT be used on other places.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-11-20 17:47:07 +01:00

121 lines
3.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ACPI_VIDEO_H
#define __ACPI_VIDEO_H
#include <linux/errno.h> /* for ENODEV */
#include <linux/types.h> /* for bool */
struct acpi_video_brightness_flags {
u8 _BCL_no_ac_battery_levels:1; /* no AC/Battery levels in _BCL */
u8 _BCL_reversed:1; /* _BCL package is in a reversed order */
u8 _BQC_use_index:1; /* _BQC returns an index value */
};
struct acpi_video_device_brightness {
int curr;
int count;
int *levels;
struct acpi_video_brightness_flags flags;
};
struct acpi_device;
#define ACPI_VIDEO_CLASS "video"
#define ACPI_VIDEO_DISPLAY_CRT 1
#define ACPI_VIDEO_DISPLAY_TV 2
#define ACPI_VIDEO_DISPLAY_DVI 3
#define ACPI_VIDEO_DISPLAY_LCD 4
#define ACPI_VIDEO_DISPLAY_LEGACY_MONITOR 0x0100
#define ACPI_VIDEO_DISPLAY_LEGACY_PANEL 0x0110
#define ACPI_VIDEO_DISPLAY_LEGACY_TV 0x0200
#define ACPI_VIDEO_NOTIFY_SWITCH 0x80
#define ACPI_VIDEO_NOTIFY_PROBE 0x81
#define ACPI_VIDEO_NOTIFY_CYCLE 0x82
#define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT 0x83
#define ACPI_VIDEO_NOTIFY_PREV_OUTPUT 0x84
#define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS 0x85
#define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS 0x86
#define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS 0x87
#define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS 0x88
#define ACPI_VIDEO_NOTIFY_DISPLAY_OFF 0x89
enum acpi_backlight_type {
acpi_backlight_undef = -1,
acpi_backlight_none = 0,
acpi_backlight_video,
acpi_backlight_vendor,
acpi_backlight_native,
acpi_backlight_nvidia_wmi_ec,
acpi_backlight_apple_gmux,
};
#if IS_ENABLED(CONFIG_ACPI_VIDEO)
extern int acpi_video_register(void);
extern void acpi_video_unregister(void);
extern void acpi_video_register_backlight(void);
extern int acpi_video_get_edid(struct acpi_device *device, int type,
int device_id, void **edid);
/*
* Note: The value returned by acpi_video_handles_brightness_key_presses()
* may change over time and should not be cached.
*/
extern bool acpi_video_handles_brightness_key_presses(void);
extern int acpi_video_get_levels(struct acpi_device *device,
struct acpi_video_device_brightness **dev_br,
int *pmax_level);
extern enum acpi_backlight_type __acpi_video_get_backlight_type(bool native,
bool *auto_detect);
static inline enum acpi_backlight_type acpi_video_get_backlight_type(void)
{
return __acpi_video_get_backlight_type(false, NULL);
}
/*
* This function MUST only be called by GPU drivers to check if the driver
* should register a backlight class device. This function not only checks
* if a GPU native backlight device should be registered it *also* tells
* the ACPI video-detect code that native GPU backlight control is available.
* Therefor calling this from any place other then the GPU driver is wrong!
* To check if GPU native backlight control is used in other places instead use:
* if (acpi_video_get_backlight_type() == acpi_backlight_native) { ... }
*/
static inline bool acpi_video_backlight_use_native(void)
{
return __acpi_video_get_backlight_type(true, NULL) == acpi_backlight_native;
}
#else
static inline int acpi_video_register(void) { return -ENODEV; }
static inline void acpi_video_unregister(void) { return; }
static inline void acpi_video_register_backlight(void) { return; }
static inline int acpi_video_get_edid(struct acpi_device *device, int type,
int device_id, void **edid)
{
return -ENODEV;
}
static inline enum acpi_backlight_type acpi_video_get_backlight_type(void)
{
return acpi_backlight_vendor;
}
static inline bool acpi_video_backlight_use_native(void)
{
return true;
}
static inline bool acpi_video_handles_brightness_key_presses(void)
{
return false;
}
static inline int acpi_video_get_levels(struct acpi_device *device,
struct acpi_video_device_brightness **dev_br,
int *pmax_level)
{
return -ENODEV;
}
#endif
#endif