How to access GPIO on Android pie?

Technical Support
1

Dears, @Terry
Refer to Android 7, GPIO,
I modify mesongxl.dtsi on android pie as below:

— a/arch/arm/boot/dts/amlogic/mesongxl.dtsi
+++ b/arch/arm/boot/dts/amlogic/mesongxl.dtsi
@@ -250,7 +250,7 @@

    jtag {
            compatible = "amlogic, jtag";

  •           status = "okay";

  •           status = "disabled";
          select = "apao"; /* disable/apao/apee */
          jtagao-gpios = <&gpio   GPIOH_6         0
                          &gpio   GPIOH_7         0

Then，write /sys/class/gpio， but “gpio176” not found no such file as below:

kvim:/sys/class/gpio # ls
export gpiochip401 gpiochip501 unexport
kvim:/sys/class/gpio # echo 176 > export
1|kvim:/sys/class/gpio # ls
export gpiochip401 gpiochip501 unexport
kvim:/sys/class/gpio #

what other config file in kernel need to modify ?? Could you please show me how to do it ??
Thank you very much !

2

1.in arch/arm/boot/dts/amlogic/kvim.dts
remove pinctrl-0 = <&audio_i2s_pins>;

2.in arch/arm/boot/dts/amlogic/mesongxl.dtsi
jtag {
compatible = “amlogic, jtag”;

  •           status = "okay";

  •           status = "disabled";

3.rebuild Android

4.write node: (GPIOH_7 number: 401 - 0 + 23 = 424)
kvim:/sys/class/gpio # echo 424 > export
kvim:/sys/class/gpio # echo out > gpio424/direction
kvim:/sys/class/gpio # cat gpio424/value
0
kvim:/sys/class/gpio # echo 1 > gpio424/value
kvim:/sys/class/gpio # echo 0 > gpio424/value

3

Hello,
I am new for VIM3, Where can I find the kvim.dts in android pie and how to find this file?

4

You can find the kvim3.dts in the path