Brooklyn/arch/arm/boot/dts/overlays/hdmi-backlight-hwhack-gpio-overlay.dts

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/*
* Devicetree overlay for GPIO based backlight on/off capability.
*
* Use this if you have one of those HDMI displays whose backlight cannot be
* controlled via DPMS over HDMI and plan to do a little soldering to use an
* RPi gpio pin for on/off switching.
*
* See: https://www.waveshare.com/wiki/7inch_HDMI_LCD_(C)#Backlight_Control
*
*/
/dts-v1/;
/plugin/;
/ {
compatible = "brcm,bcm2835";
fragment@1 {
target = <&gpio>;
__overlay__ {
hdmi_backlight_hwhack_gpio_pins: hdmi_backlight_hwhack_gpio_pins {
brcm,pins = <17>;
brcm,function = <1>; /* out */
};
};
};
fragment@2 {
target-path = "/";
__overlay__ {
hdmi_backlight_hwhack_gpio: hdmi_backlight_hwhack_gpio {
compatible = "gpio-backlight";
pinctrl-names = "default";
pinctrl-0 = <&hdmi_backlight_hwhack_gpio_pins>;
gpios = <&gpio 17 0>;
default-on;
};
};
};
__overrides__ {
gpio_pin = <&hdmi_backlight_hwhack_gpio>,"gpios:4",
<&hdmi_backlight_hwhack_gpio_pins>,"brcm,pins:0";
active_low = <&hdmi_backlight_hwhack_gpio>,"gpios:8";
};
};