linux/include/acpi/video.h
Hans de Goede cd8e468efb ACPI: video: Add Dell UART backlight controller detection
Dell All In One (AIO) models released after 2017 use a backlight
controller board connected to an UART.

In DSDT this uart port will be defined as:

   Name (_HID, "DELL0501")
   Name (_CID, EisaId ("PNP0501")

Commit 484bae9e4d ("platform/x86: Add new Dell UART backlight driver")
has added support for this, but I neglected to tie this into
acpi_video_get_backlight_type().

Now the first AIO has turned up which has not only the DSDT bits for this,
but also an actual controller attached to the UART, yet it is not using
this controller for backlight control.

Add support to acpi_video_get_backlight_type() for a new dell_uart
backlight type. So that the existing infra to override the backlight
control method on the commandline or with DMI quirks can be used.

Fixes: 484bae9e4d ("platform/x86: Add new Dell UART backlight driver")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Link: https://patch.msgid.link/20240814190159.15650-2-hdegoede@redhat.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-08-19 15:58:35 +02:00

122 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,
acpi_backlight_dell_uart,
};
#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