1What:		/sys/class/backlight/<backlight>/scale
2Date:		July 2019
3KernelVersion:	5.4
4Contact:	Daniel Thompson <daniel.thompson@linaro.org>
5Description:
6		Description of the scale of the brightness curve.
7
8		The human eye senses brightness approximately logarithmically,
9		hence linear changes in brightness are perceived as being
10		non-linear. To achieve a linear perception of brightness changes
11		controls like sliders need to apply a logarithmic mapping for
12		backlights with a linear brightness curve.
13
14		Possible values of the attribute are:
15
16		unknown
17		  The scale of the brightness curve is unknown.
18
19		linear
20		  The brightness changes linearly with each step. Brightness
21		  controls should apply a logarithmic mapping for a linear
22		  perception.
23
24		non-linear
25		  The brightness changes non-linearly with each step. Brightness
26		  controls should use a linear mapping for a linear perception.
27
28What:		/sys/class/backlight/<backlight>/ambient_light_level
29Date:		Apr, 2010
30KernelVersion:	v2.6.35
31Contact:	Michael Hennerich <michael.hennerich@analog.com>
32Description:
33		(RO) Get conversion value of the light sensor.
34
35		The value is automatically updated every 80 ms when the
36		light sensor is enabled.
37
38		The value range is device-driver specific:
39
40		For ADP8870:
41
42		  It returns integer between 0 (dark) and 8000 (max ambient
43		  brightness).
44
45		For ADP8860:
46
47		  It returns a 13-bits integer.
48
49What:		/sys/class/backlight/<backlight>/ambient_light_zone
50Date:		Apr, 2010
51KernelVersion:	v2.6.35
52Contact:	Michael Hennerich <michael.hennerich@analog.com>,
53		device-drivers-devel@blackfin.uclinux.org
54
55Description:
56		(RW) Read or write the specific brightness level at which the
57		backlight operates.
58
59		The value meaning is device-driver specific:
60
61		For ADP8860:
62
63		  ==	==========================
64		   0	Off: Backlight set to 0 mA
65		   1	Level 1: daylight
66		   2	Level 2: bright
67		   3	Level 3: dark
68		  ==	==========================
69
70		For ADP8870:
71
72		  ==	==========================
73		   0	Off: Backlight set to 0 mA
74		   1	Level 1: daylight
75		   2	Level 2: bright
76		   3	Level 3: office
77		   4	Level 4: indoor
78		   5	Level 5: dark
79		  ==	==========================
80
81		Writing 0 returns to normal/automatic ambient light level
82		operation.
83
84		It can be enabled by writing the value stored in
85		/sys/class/backlight/<backlight>/max_brightness to
86		/sys/class/backlight/<backlight>/brightness.
87
88What:		/sys/class/backlight/<backlight>/<ambient light zone>_max
89Date:		Sep, 2009
90KernelVersion:	v2.6.32
91Contact:	device-drivers-devel@blackfin.uclinux.org
92Description:
93		Control the maximum brightness for <ambient light zone>
94		on this <backlight>. Values are between 0 and 127. This file
95		will also show the brightness level stored for this
96		<ambient light zone>.
97
98		The <ambient light zone> is device-driver specific:
99
100		For ADP5520 and ADP5501, <ambient light zone> can be:
101
102		===========  ================================================
103		Ambient      sysfs entry
104		light zone
105		===========  ================================================
106		daylight     /sys/class/backlight/<backlight>/daylight_max
107		office       /sys/class/backlight/<backlight>/office_max
108		dark         /sys/class/backlight/<backlight>/dark_max
109		===========  ================================================
110
111		For ADP8860, <ambient light zone> can be:
112
113		===========  ================================================
114		Ambient      sysfs entry
115		light zone
116		===========  ================================================
117		l1_daylight  /sys/class/backlight/<backlight>/l1_daylight_max
118		l2_office    /sys/class/backlight/<backlight>/l2_office_max
119		l3_dark      /sys/class/backlight/<backlight>/l3_dark_max
120		===========  ================================================
121
122		For ADP8870, <ambient light zone> can be:
123
124		===========  ================================================
125		Ambient      sysfs entry
126		light zone
127		===========  ================================================
128		l1_daylight  /sys/class/backlight/<backlight>/l1_daylight_max
129		l2_bright    /sys/class/backlight/<backlight>/l2_bright_max
130		l3_office    /sys/class/backlight/<backlight>/l3_office_max
131		l4_indoor    /sys/class/backlight/<backlight>/l4_indoor_max
132		l5_dark      /sys/class/backlight/<backlight>/l5_dark_max
133		===========  ================================================
134
135		See also: /sys/class/backlight/<backlight>/ambient_light_zone.
136
137What:		/sys/class/backlight/<backlight>/<ambient light zone>_dim
138Date:		Sep, 2009
139KernelVersion:	v2.6.32
140Contact:	device-drivers-devel@blackfin.uclinux.org
141Description:
142		Control the dim brightness for <ambient light zone>
143		on this <backlight>. Values are between 0 and 127, typically
144		set to 0. Full off when the backlight is disabled.
145		This file will also show the dim brightness level stored for
146		this <ambient light zone>.
147
148		The <ambient light zone> is device-driver specific:
149
150		For ADP5520 and ADP5501, <ambient light zone> can be:
151
152		===========  ================================================
153		Ambient      sysfs entry
154		light zone
155		===========  ================================================
156		daylight     /sys/class/backlight/<backlight>/daylight_dim
157		office       /sys/class/backlight/<backlight>/office_dim
158		dark         /sys/class/backlight/<backlight>/dark_dim
159		===========  ================================================
160
161		For ADP8860, <ambient light zone> can be:
162
163		===========  ================================================
164		Ambient      sysfs entry
165		light zone
166		===========  ================================================
167		l1_daylight  /sys/class/backlight/<backlight>/l1_daylight_dim
168		l2_office    /sys/class/backlight/<backlight>/l2_office_dim
169		l3_dark      /sys/class/backlight/<backlight>/l3_dark_dim
170		===========  ================================================
171
172		For ADP8870, <ambient light zone> can be:
173
174		===========  ================================================
175		Ambient      sysfs entry
176		light zone
177		===========  ================================================
178		l1_daylight  /sys/class/backlight/<backlight>/l1_daylight_dim
179		l2_bright    /sys/class/backlight/<backlight>/l2_bright_dim
180		l3_office    /sys/class/backlight/<backlight>/l3_office_dim
181		l4_indoor    /sys/class/backlight/<backlight>/l4_indoor_dim
182		l5_dark      /sys/class/backlight/<backlight>/l5_dark_dim
183		===========  ================================================
184
185		See also: /sys/class/backlight/<backlight>/ambient_light_zone.
186
187