acpi-video-detect: Rewrite backlight interface selection logic
Currently we have 2 kernel commandline options + dmi-quirks in 3 places all
interacting (in interesting ways) to select which which backlight interface
to use. On the commandline we've acpi_backlight=[video|vendor] and
video.use_native_backlight=[0|1]. DMI quirks we have in
acpi/video-detect.c, acpi/video.c and drivers/platform/x86/*.c .
This commit is the first step to cleaning this up, replacing the 2 cmdline
options with just acpi_backlight=[video|vendor|native|none], and adds a
new API to video_detect.c to reflect this.
Follow up commits will also move other related code, like unregistering the
acpi_video backlight interface if it was registered before other drivers
which take priority over it are loaded, to video_detect.c where this
logic really belongs.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/include/acpi/video.h b/include/acpi/video.h
index 843ef1a..01b5cc7 100644
--- a/include/acpi/video.h
+++ b/include/acpi/video.h
@@ -16,6 +16,14 @@
#define ACPI_VIDEO_DISPLAY_LEGACY_PANEL 0x0110
#define ACPI_VIDEO_DISPLAY_LEGACY_TV 0x0200
+enum acpi_backlight_type {
+ acpi_backlight_undef = -1,
+ acpi_backlight_none = 0,
+ acpi_backlight_video,
+ acpi_backlight_vendor,
+ acpi_backlight_native,
+};
+
#if (defined CONFIG_ACPI_VIDEO || defined CONFIG_ACPI_VIDEO_MODULE)
extern int acpi_video_register(void);
extern void acpi_video_unregister(void);
@@ -23,6 +31,8 @@
extern int acpi_video_get_edid(struct acpi_device *device, int type,
int device_id, void **edid);
extern bool acpi_video_verify_backlight_support(void);
+extern enum acpi_backlight_type acpi_video_get_backlight_type(void);
+extern void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type);
#else
static inline int acpi_video_register(void) { return 0; }
static inline void acpi_video_unregister(void) { return; }
@@ -33,6 +43,13 @@
return -ENODEV;
}
static inline bool acpi_video_verify_backlight_support(void) { return false; }
+static inline enum acpi_backlight_type acpi_video_get_backlight_type(void)
+{
+ return acpi_backlight_vendor;
+}
+static void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)
+{
+}
#endif
#endif