| // 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 <marek.vasut+renesas@mailbox.org> |
| * |
| * 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>; |
| }; |
| }; |
