15f634c65SCorentin CharyWhat: /sys/class/leds/<led>/brightness 25f634c65SCorentin CharyDate: March 2006 35f634c65SCorentin CharyKernelVersion: 2.6.17 45f634c65SCorentin CharyContact: Richard Purdie <rpurdie@rpsys.net> 55f634c65SCorentin CharyDescription: 65f634c65SCorentin Chary Set the brightness of the LED. Most LEDs don't 7ed25e9caSPavel Machek have hardware brightness support, so will just be turned on for 85f634c65SCorentin Chary non-zero brightness settings. The value is between 0 and 95f634c65SCorentin Chary /sys/class/leds/<led>/max_brightness. 105f634c65SCorentin Chary 11ed25e9caSPavel Machek Writing 0 to this file clears active trigger. 12ed25e9caSPavel Machek 13ed25e9caSPavel Machek Writing non-zero to this file while trigger is active changes the 14ed25e9caSPavel Machek top brightness trigger is going to use. 15ed25e9caSPavel Machek 165f634c65SCorentin CharyWhat: /sys/class/leds/<led>/max_brightness 175f634c65SCorentin CharyDate: March 2006 185f634c65SCorentin CharyKernelVersion: 2.6.17 195f634c65SCorentin CharyContact: Richard Purdie <rpurdie@rpsys.net> 205f634c65SCorentin CharyDescription: 21ed25e9caSPavel Machek Maximum brightness level for this LED, default is 255 (LED_FULL). 22ed25e9caSPavel Machek 23ed25e9caSPavel Machek If the LED does not support different brightness levels, this 24ed25e9caSPavel Machek should be 1. 255f634c65SCorentin Chary 260cb8eb30SHans de GoedeWhat: /sys/class/leds/<led>/brightness_hw_changed 270cb8eb30SHans de GoedeDate: January 2017 280cb8eb30SHans de GoedeKernelVersion: 4.11 290cb8eb30SHans de GoedeDescription: 300cb8eb30SHans de Goede Last hardware set brightness level for this LED. Some LEDs 310cb8eb30SHans de Goede may be changed autonomously by hardware/firmware. Only LEDs 320cb8eb30SHans de Goede where this happens and the driver can detect this, will have 330cb8eb30SHans de Goede this file. 340cb8eb30SHans de Goede 350cb8eb30SHans de Goede This file supports poll() to detect when the hardware changes 360cb8eb30SHans de Goede the brightness. 370cb8eb30SHans de Goede 380cb8eb30SHans de Goede Reading this file will return the last brightness level set 390cb8eb30SHans de Goede by the hardware, this may be different from the current 400cb8eb30SHans de Goede brightness. Reading this file when no hw brightness change 410cb8eb30SHans de Goede event has happened will return an ENODATA error. 420cb8eb30SHans de Goede 435f634c65SCorentin CharyWhat: /sys/class/leds/<led>/trigger 445f634c65SCorentin CharyDate: March 2006 455f634c65SCorentin CharyKernelVersion: 2.6.17 465f634c65SCorentin CharyContact: Richard Purdie <rpurdie@rpsys.net> 475f634c65SCorentin CharyDescription: 485f634c65SCorentin Chary Set the trigger for this LED. A trigger is a kernel based source 49ed25e9caSPavel Machek of LED events. 505f634c65SCorentin Chary You can change triggers in a similar manner to the way an IO 515f634c65SCorentin Chary scheduler is chosen. Trigger specific parameters can appear in 521f70cb40SRafał Miłecki /sys/class/leds/<led> once a given trigger is selected. For 53*34433332SMauro Carvalho Chehab their documentation see `sysfs-class-led-trigger-*`. 545f634c65SCorentin Chary 559f9455aeSJanusz KrzysztofikWhat: /sys/class/leds/<led>/inverted 569f9455aeSJanusz KrzysztofikDate: January 2011 579f9455aeSJanusz KrzysztofikKernelVersion: 2.6.38 589f9455aeSJanusz KrzysztofikContact: Richard Purdie <rpurdie@rpsys.net> 599f9455aeSJanusz KrzysztofikDescription: 609f9455aeSJanusz Krzysztofik Invert the LED on/off state. This parameter is specific to 619f9455aeSJanusz Krzysztofik gpio and backlight triggers. In case of the backlight trigger, 6225985edcSLucas De Marchi it is useful when driving a LED which is intended to indicate 639f9455aeSJanusz Krzysztofik a device in a standby like state. 64