Merge tag 'backlight-next-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

Pull backlight updates from Lee Jones:
 "Core Frameworks
   - Obtain scale type through sysfs

  New Functionality:
   - Provide Device Tree functionality in rave-sp-backlight
   - Calculate if scale type is (non-)linear in pwm_bl

  Fix-ups:
   - Simplify code in lm3630a_bl
   - Trivial rename/whitespace/typo fixes in lms283gf05
   - Remove superfluous NULL check in tosa_lcd
   - Fix power state initialisation in gpio_backlight
   - List supported file in MAINTAINERS

  Bug Fixes:
   - Kconfig - default to not building unless requested in
     {LED,BACKLIGHT}_CLASS_DEVICE"

* tag 'backlight-next-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
  backlight: pwm_bl: Set scale type for brightness curves specified in the DT
  backlight: pwm_bl: Set scale type for CIE 1931 curves
  backlight: Expose brightness curve type through sysfs
  MAINTAINERS: Add entry for stable backlight sysfs ABI documentation
  backlight: gpio-backlight: Correct initial power state handling
  video: backlight: tosa_lcd: drop check because i2c_unregister_device() is NULL safe
  video: backlight: Drop default m for {LCD,BACKLIGHT_CLASS_DEVICE}
  backlight: lms283gf05: Fix a typo in the description passed to 'devm_gpio_request_one()'
  backlight: lm3630a: Switch to use fwnode_property_count_uXX()
  backlight: rave-sp: Leave initial state and register with correct device

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/backlight.h b/include/linux/backlight.h
index 0b5897446dca..c7d6b2e8c3b5 100644
--- a/include/linux/backlight.h
+++ b/include/linux/backlight.h
@@ -46,6 +46,12 @@ enum backlight_notification {
         BACKLIGHT_UNREGISTERED,
 };
 
+enum backlight_scale {
+        BACKLIGHT_SCALE_UNKNOWN = 0,
+        BACKLIGHT_SCALE_LINEAR,
+        BACKLIGHT_SCALE_NON_LINEAR,
+};
+
 struct backlight_device;
 struct fb_info;
 
@@ -80,6 +86,8 @@ struct backlight_properties {
         enum backlight_type type;
         /* Flags used to signal drivers of state changes */
         unsigned int state;
+        /* Type of the brightness scale (linear, non-linear, ...) */
+        enum backlight_scale scale;
 
 #define BL_CORE_SUSPENDED       (1 << 0)        /* backlight is suspended */
 #define BL_CORE_FBBLANK         (1 << 1)        /* backlight is under an fb blank event */