1.. SPDX-License-Identifier: GPL-2.0 2 3=========================================================== 4Kernel driver for Intel Cherry Trail Whiskey Cove PMIC LEDs 5=========================================================== 6 7/sys/class/leds/<led>/hw_pattern 8-------------------------------- 9 10Specify a hardware pattern for the Whiskey Cove PMIC LEDs. 11 12The only supported pattern is hardware breathing mode:: 13 14 "0 2000 1 2000" 15 16 ^ 17 | 18 Max-| --- 19 | / \ 20 | / \ 21 | / \ / 22 | / \ / 23 Min-|- --- 24 | 25 0------2------4--> time (sec) 26 27The rise and fall times must be the same value. 28Supported values are 2000, 1000, 500 and 250 for 29breathing frequencies of 1/4, 1/2, 1 and 2 Hz. 30 31The set pattern only controls the timing. For max brightness the last 32set brightness is used and the max brightness can be changed 33while breathing by writing the brightness attribute. 34 35This is just like how blinking works in the LED subsystem, 36for both sw and hw blinking the brightness can also be changed 37while blinking. Breathing on this hw really is just a variant 38mode of blinking. 39