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Diffstat (limited to 'Documentation/ABI/testing/sysfs-class-backlight')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-backlight | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-backlight b/Documentation/ABI/testing/sysfs-class-backlight new file mode 100644 index 0000000000..c453646b06 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-backlight @@ -0,0 +1,186 @@ +What: /sys/class/backlight/<backlight>/scale +Date: July 2019 +KernelVersion: 5.4 +Contact: Daniel Thompson <daniel.thompson@linaro.org> +Description: + Description of the scale of the brightness curve. + + The human eye senses brightness approximately logarithmically, + hence linear changes in brightness are perceived as being + non-linear. To achieve a linear perception of brightness changes + controls like sliders need to apply a logarithmic mapping for + backlights with a linear brightness curve. + + Possible values of the attribute are: + + unknown + The scale of the brightness curve is unknown. + + linear + The brightness changes linearly with each step. Brightness + controls should apply a logarithmic mapping for a linear + perception. + + non-linear + The brightness changes non-linearly with each step. Brightness + controls should use a linear mapping for a linear perception. + +What: /sys/class/backlight/<backlight>/ambient_light_level +Date: Apr, 2010 +KernelVersion: v2.6.35 +Contact: Michael Hennerich <michael.hennerich@analog.com> +Description: + (RO) Get conversion value of the light sensor. + + The value is automatically updated every 80 ms when the + light sensor is enabled. + + The value range is device-driver specific: + + For ADP8870: + + It returns integer between 0 (dark) and 8000 (max ambient + brightness). + + For ADP8860: + + It returns a 13-bits integer. + +What: /sys/class/backlight/<backlight>/ambient_light_zone +Date: Apr, 2010 +KernelVersion: v2.6.35 +Contact: Michael Hennerich <michael.hennerich@analog.com>, + device-drivers-devel@blackfin.uclinux.org + +Description: + (RW) Read or write the specific brightness level at which the + backlight operates. + + The value meaning is device-driver specific: + + For ADP8860: + + == ========================== + 0 Off: Backlight set to 0 mA + 1 Level 1: daylight + 2 Level 2: bright + 3 Level 3: dark + == ========================== + + For ADP8870: + + == ========================== + 0 Off: Backlight set to 0 mA + 1 Level 1: daylight + 2 Level 2: bright + 3 Level 3: office + 4 Level 4: indoor + 5 Level 5: dark + == ========================== + + Writing 0 returns to normal/automatic ambient light level + operation. + + It can be enabled by writing the value stored in + /sys/class/backlight/<backlight>/max_brightness to + /sys/class/backlight/<backlight>/brightness. + +What: /sys/class/backlight/<backlight>/<ambient light zone>_max +Date: Sep, 2009 +KernelVersion: v2.6.32 +Contact: device-drivers-devel@blackfin.uclinux.org +Description: + Control the maximum brightness for <ambient light zone> + on this <backlight>. Values are between 0 and 127. This file + will also show the brightness level stored for this + <ambient light zone>. + + The <ambient light zone> is device-driver specific: + + For ADP5520 and ADP5501, <ambient light zone> can be: + + =========== ================================================ + Ambient sysfs entry + light zone + =========== ================================================ + daylight /sys/class/backlight/<backlight>/daylight_max + office /sys/class/backlight/<backlight>/office_max + dark /sys/class/backlight/<backlight>/dark_max + =========== ================================================ + + For ADP8860, <ambient light zone> can be: + + =========== ================================================ + Ambient sysfs entry + light zone + =========== ================================================ + l1_daylight /sys/class/backlight/<backlight>/l1_daylight_max + l2_office /sys/class/backlight/<backlight>/l2_office_max + l3_dark /sys/class/backlight/<backlight>/l3_dark_max + =========== ================================================ + + For ADP8870, <ambient light zone> can be: + + =========== ================================================ + Ambient sysfs entry + light zone + =========== ================================================ + l1_daylight /sys/class/backlight/<backlight>/l1_daylight_max + l2_bright /sys/class/backlight/<backlight>/l2_bright_max + l3_office /sys/class/backlight/<backlight>/l3_office_max + l4_indoor /sys/class/backlight/<backlight>/l4_indoor_max + l5_dark /sys/class/backlight/<backlight>/l5_dark_max + =========== ================================================ + + See also: /sys/class/backlight/<backlight>/ambient_light_zone. + +What: /sys/class/backlight/<backlight>/<ambient light zone>_dim +Date: Sep, 2009 +KernelVersion: v2.6.32 +Contact: device-drivers-devel@blackfin.uclinux.org +Description: + Control the dim brightness for <ambient light zone> + on this <backlight>. Values are between 0 and 127, typically + set to 0. Full off when the backlight is disabled. + This file will also show the dim brightness level stored for + this <ambient light zone>. + + The <ambient light zone> is device-driver specific: + + For ADP5520 and ADP5501, <ambient light zone> can be: + + =========== ================================================ + Ambient sysfs entry + light zone + =========== ================================================ + daylight /sys/class/backlight/<backlight>/daylight_dim + office /sys/class/backlight/<backlight>/office_dim + dark /sys/class/backlight/<backlight>/dark_dim + =========== ================================================ + + For ADP8860, <ambient light zone> can be: + + =========== ================================================ + Ambient sysfs entry + light zone + =========== ================================================ + l1_daylight /sys/class/backlight/<backlight>/l1_daylight_dim + l2_office /sys/class/backlight/<backlight>/l2_office_dim + l3_dark /sys/class/backlight/<backlight>/l3_dark_dim + =========== ================================================ + + For ADP8870, <ambient light zone> can be: + + =========== ================================================ + Ambient sysfs entry + light zone + =========== ================================================ + l1_daylight /sys/class/backlight/<backlight>/l1_daylight_dim + l2_bright /sys/class/backlight/<backlight>/l2_bright_dim + l3_office /sys/class/backlight/<backlight>/l3_office_dim + l4_indoor /sys/class/backlight/<backlight>/l4_indoor_dim + l5_dark /sys/class/backlight/<backlight>/l5_dark_dim + =========== ================================================ + + See also: /sys/class/backlight/<backlight>/ambient_light_zone. + |