| 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. |
| |
