MIRRORS/linux-imx
1
0
Fork 0
mirror of https://github.com/nxp-imx/linux-imx.git synced 2025-07-18 23:29:57 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity
ef901b38d3
linux-imx/Documentation/ABI/testing/sysfs-class-backlight
Mauro Carvalho Chehab 13d6f96750 docs: ABI: sysfs-class-backlight: unify ambient light zone nodes 
./scripts/get_abi.pl is warning about duplicated symbol
definition:

	Warning: /sys/class/backlight/<backlight>/l1_daylight_max is defined 2 times:  ./Documentation/ABI/testing/sysfs-class-backlight-driver-adp8870:4  ./Documentation/ABI/testing/sysfs-class-backlight-adp8860:12

What happens is that 3 drivers use the same pattern to report
max and dim setting for different ambient light zones.

It should be noticed that the adp8870 doc was missing an
entry for l1_daylight_dim, which was fixed on this patch.

While the ambient light zone is device-specific, the sysfs
definition is actually common. So, unify them at:

	Documentation/ABI/testing/sysfs-class-backlight

and use as the contact point, the e-mail reported by
get_maintainers.pl for the subsystem.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/c13c6ebd03cd04a0d15d89018f8d529918fc0a73.1621413933.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-05-20 13:44:14 -06:00

6.3 KiB
Raw Blame History

What: /sys/class/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//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//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//_max Date: Sep, 2009 KernelVersion: v2.6.32 Contact: device-drivers-devel@blackfin.uclinux.org Description: Control the maximum brightness for on this . Values are between 0 and 127. This file will also show the brightness level stored for this .

	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//_dim Date: Sep, 2009 KernelVersion: v2.6.32 Contact: device-drivers-devel@blackfin.uclinux.org Description: Control the dim brightness for on this . 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 .

	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.