39 lines
1.4 KiB
Plaintext
39 lines
1.4 KiB
Plaintext
// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
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/*
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* Device Tree Overlay for the PWM controlled blower fan on connector J3:FAN
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* on R-Car V4H ES3.0 Sparrow Hawk board
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*
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* Copyright (C) 2025 Marek Vasut <marek.vasut+renesas@mailbox.org>
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*
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* Example usage:
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*
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* # Localize hwmon sysfs directory that matches the PWM fan,
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* # enable the PWM fan, and configure the fan speed manually.
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* r8a779g3-sparrow-hawk$ ls -1 /sys/devices/platform/pwm-fan/hwmon/hwmon?/pwm?_enable
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* /sys/devices/platform/pwm-fan/hwmon/hwmon4/pwm1_enable
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*
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* # Select mode 2 , enable fan PWM and regulator and keep them enabled.
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* # For details, see Linux Documentation/hwmon/pwm-fan.rst
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* r8a779g3-sparrow-hawk$ echo 2 > /sys/devices/platform/pwm-fan/hwmon/hwmon4/pwm1_enable
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*
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* # Configure PWM fan speed in range 0..255 , 0 is stopped , 255 is full speed .
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* # Fan speed 101 is about 2/5 of the PWM fan speed:
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* r8a779g3-sparrow-hawk$ echo 101 > /sys/devices/platform/pwm-fan/hwmon/hwmon4/pwm1
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*/
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/dts-v1/;
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/plugin/;
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/*
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* Override default PWM fan settings. For a list of available properties,
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* see schema Documentation/devicetree/bindings/hwmon/pwm-fan.yaml .
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*/
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&fan {
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/* Available cooling levels */
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cooling-levels = <0 50 100 150 200 255>;
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/* Four pulses of tacho signal per one revolution */
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pulses-per-revolution = <4>;
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/* PWM period: 100us ~= 10 kHz */
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pwms = <&pwm0 0 100000>;
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};
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