PINE64
need a dts file to set some pins as pulldown interrupts in kernel using a DTO - Printable Version

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+--- Thread: need a dts file to set some pins as pulldown interrupts in kernel using a DTO (/showthread.php?tid=9035)

need a dts file to set some pins as pulldown interrupts in kernel using a DTO - dkebler - 02-05-2020

I am using the latest stable ayufan bionic

I need to use a few of the gpio pins as input interrupts.   In an RPI that is a simple is setting a line the the /boot/firmware/config.txt file.
ex.  gpio=9,10,24,4=pd   to set pins 0.10,24,4 as pulldowns

But I guess that method has not been copied in the ayufan image.

That leaves me to rebuild the kernel (not wanting to do that) or use a DTO which I understand is a way to add functionality to the kernel without a complete recompile.

So I gotta believe someone has had a need of pins as interrupts on the rock64 and already has a working dts file.

Besides being some pretty arcane syntax I can find no docs on this that pertain specifically to the rock64 let alone a sample dts file.

Can anyone help out here with a working dts file and some details about how to compile/register it so it gets picked up at boot.

here for example is a beagle black dts file about all I could find.


Code:
  /*
   * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Purpose License Version 2 as
   * published by the Free Software Foundation
   *
   * Original from: github.com/jadonk/validation-scripts/blob/master/test-capemgr/
   *
   * Modified by Derek Molloy for the example on www.derekmolloy.ie
   * that maps GPIO pins for the example
   */

   /dts-v1/;
   /plugin/;

   /{
       compatible = "ti,beaglebone", "ti,beaglebone-black";
       part-number = "WEIGU1";
       version = "00A0";
       fragment@0 {
           target = <&am33xx_pinmux>;
           __overlay__ {
               pinctrl_test: DM_GPIO_Test_Pins {
                   pinctrl-single,pins = <
                       0x044 0x07  /* P9_23 49  OUTPUT MODE7 - MUXA */
                       0x040 0x07  /* P9_15 48  OUTPUT MODE7 - MUXB */
                       0x1ac 0x07  /* P9_25 117 OUTPUT MODE7 - MUXT conflict mcasp0! */
                       0x0a4 0x07  /* P8_46 71  OUTPUT MODE7 - RTS conflict hdmi_bonelt! */
                       /* OUTPUT  GPIO(mode7) 0x07 pulldown, 0x17 pullup, 0x?f no pullup/down */
                       /* INPUT   GPIO(mode7) 0x27 pulldown, 0x37 pullup, 0x?f no pullup/down */
                   >;
               };
           };
       };

       fragment@1 {
           target = <&ocp>;
           __overlay__ {
               test_helper: helper {
                   compatible = "bone-pinmux-helper";
                   pinctrl-names = "default";
                   pinctrl-0 = <&pinctrl_test>;
                   status = "okay";
               };
           };
       };
   };