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 26*0cb8eb30SHans de GoedeWhat: /sys/class/leds/<led>/brightness_hw_changed 27*0cb8eb30SHans de GoedeDate: January 2017 28*0cb8eb30SHans de GoedeKernelVersion: 4.11 29*0cb8eb30SHans de GoedeDescription: 30*0cb8eb30SHans de Goede Last hardware set brightness level for this LED. Some LEDs 31*0cb8eb30SHans de Goede may be changed autonomously by hardware/firmware. Only LEDs 32*0cb8eb30SHans de Goede where this happens and the driver can detect this, will have 33*0cb8eb30SHans de Goede this file. 34*0cb8eb30SHans de Goede 35*0cb8eb30SHans de Goede This file supports poll() to detect when the hardware changes 36*0cb8eb30SHans de Goede the brightness. 37*0cb8eb30SHans de Goede 38*0cb8eb30SHans de Goede Reading this file will return the last brightness level set 39*0cb8eb30SHans de Goede by the hardware, this may be different from the current 40*0cb8eb30SHans de Goede brightness. Reading this file when no hw brightness change 41*0cb8eb30SHans de Goede event has happened will return an ENODATA error. 42*0cb8eb30SHans 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 531f70cb40SRafał Miłecki 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