summaryrefslogtreecommitdiffstats
path: root/Documentation/ABI/testing/sysfs-class-backlight
blob: c453646b06e2c693e516020ba2c7c6ae18684aeb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
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.