1*45447550SMarek Vasut// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2*45447550SMarek Vasut/* 3*45447550SMarek Vasut * Device Tree Overlay for the Argon40 HAT blower fan on connector CN7 4*45447550SMarek Vasut * on R-Car V4H ES3.0 Sparrow Hawk board 5*45447550SMarek Vasut * 6*45447550SMarek Vasut * Copyright (C) 2025 Marek Vasut <marek.vasut+renesas@mailbox.org> 7*45447550SMarek Vasut * 8*45447550SMarek Vasut * Example usage: 9*45447550SMarek Vasut * 10*45447550SMarek Vasut * # Localize hwmon sysfs directory that matches the PWM fan, 11*45447550SMarek Vasut * # enable the PWM fan, and configure the fan speed manually. 12*45447550SMarek Vasut * r8a779g3-sparrow-hawk$ ls -1 /sys/devices/platform/pwm-fan-ext/hwmon/hwmon?/pwm?_enable 13*45447550SMarek Vasut * /sys/devices/platform/pwm-fan-ext/hwmon/hwmon0/pwm1_enable 14*45447550SMarek Vasut * 15*45447550SMarek Vasut * # Select mode 2 , enable fan PWM and regulator and keep them enabled. 16*45447550SMarek Vasut * # For details, see Linux Documentation/hwmon/pwm-fan.rst 17*45447550SMarek Vasut * r8a779g3-sparrow-hawk$ echo 2 > /sys/devices/platform/pwm-fan-ext/hwmon/hwmon0/pwm1_enable 18*45447550SMarek Vasut * 19*45447550SMarek Vasut * # Configure PWM fan speed in range 0..255 , 0 is stopped , 255 is full speed . 20*45447550SMarek Vasut * # Fan speed 101 is about 2/5 of the PWM fan speed: 21*45447550SMarek Vasut * r8a779g3-sparrow-hawk$ echo 101 > /sys/devices/platform/pwm-fan-ext/hwmon/hwmon0/pwm1 22*45447550SMarek Vasut */ 23*45447550SMarek Vasut 24*45447550SMarek Vasut/dts-v1/; 25*45447550SMarek Vasut/plugin/; 26*45447550SMarek Vasut 27*45447550SMarek Vasut&{/} { 28*45447550SMarek Vasut pwm-fan-ext { 29*45447550SMarek Vasut compatible = "pwm-fan"; 30*45447550SMarek Vasut #cooling-cells = <2>; 31*45447550SMarek Vasut /* PWM period: 33us ~= 30 kHz */ 32*45447550SMarek Vasut pwms = <&pwmhat 0 33334 0>; 33*45447550SMarek Vasut /* Available cooling levels */ 34*45447550SMarek Vasut cooling-levels = <0 50 100 150 200 255>; 35*45447550SMarek Vasut fan-shutdown-percent = <100>; 36*45447550SMarek Vasut }; 37*45447550SMarek Vasut}; 38*45447550SMarek Vasut 39*45447550SMarek Vasut/* Page 31 / IO_CN */ 40*45447550SMarek Vasut&i2c3 { 41*45447550SMarek Vasut #address-cells = <1>; 42*45447550SMarek Vasut #size-cells = <0>; 43*45447550SMarek Vasut clock-frequency = <400000>; 44*45447550SMarek Vasut status = "okay"; 45*45447550SMarek Vasut 46*45447550SMarek Vasut pwmhat: pwm@1a { 47*45447550SMarek Vasut compatible = "argon40,fan-hat"; 48*45447550SMarek Vasut reg = <0x1a>; 49*45447550SMarek Vasut #pwm-cells = <3>; 50*45447550SMarek Vasut }; 51*45447550SMarek Vasut}; 52