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