// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) /* * Device Tree Overlay for the Argon40 HAT blower fan on connector CN7 * on R-Car V4H ES3.0 Sparrow Hawk board * * Copyright (C) 2025 Marek Vasut * * Example usage: * * # Localize hwmon sysfs directory that matches the PWM fan, * # enable the PWM fan, and configure the fan speed manually. * r8a779g3-sparrow-hawk$ ls -1 /sys/devices/platform/pwm-fan-ext/hwmon/hwmon?/pwm?_enable * /sys/devices/platform/pwm-fan-ext/hwmon/hwmon0/pwm1_enable * * # Select mode 2 , enable fan PWM and regulator and keep them enabled. * # For details, see Linux Documentation/hwmon/pwm-fan.rst * r8a779g3-sparrow-hawk$ echo 2 > /sys/devices/platform/pwm-fan-ext/hwmon/hwmon0/pwm1_enable * * # Configure PWM fan speed in range 0..255 , 0 is stopped , 255 is full speed . * # Fan speed 101 is about 2/5 of the PWM fan speed: * r8a779g3-sparrow-hawk$ echo 101 > /sys/devices/platform/pwm-fan-ext/hwmon/hwmon0/pwm1 */ /dts-v1/; /plugin/; &{/} { pwm-fan-ext { compatible = "pwm-fan"; #cooling-cells = <2>; /* PWM period: 33us ~= 30 kHz */ pwms = <&pwmhat 0 33334 0>; /* Available cooling levels */ cooling-levels = <0 50 100 150 200 255>; fan-shutdown-percent = <100>; }; }; /* Page 31 / IO_CN */ &i2c3 { #address-cells = <1>; #size-cells = <0>; clock-frequency = <400000>; status = "okay"; pwmhat: pwm@1a { compatible = "argon40,fan-hat"; reg = <0x1a>; #pwm-cells = <3>; }; };