apds 9960 on raspberry pi zero

Question

I would like to use the apds9960 (light/gesture sensor) on rp0 - utilizing the kernel iio driver, which is already available, but there is no dt overlay yet. I guess I need to:

• write the dts file
• compile it to dtb
• add to overlays
• specify dtoverlay in config.txt
• find the device in /sys/bus/iio/devices

Is someone able to do/help with the first point or two?

Answer 1

OK. There are current findings:

• The DTS might look like this (i2c-apds9960.dts):

  /dts-v1/;
  /plugin/;
  
  / {
      compatible = "brcm,bcm2835", "brcm,bcm2708", "brcm,bcm2709";
  
      fragment@0 {
          target = <&i2c_arm>;
          __overlay__ {
              #address-cells = <1>;
              #size-cells = <0>;
              status = "okay";
  
              apds9960: apds9960@39 {
                  compatible = "avago,apds9960";
                  reg = <0x39>;
                  interrupt-parent = <&gpio>;
                  interrupts = <4 2>;
                  #gpio-cells = <2>;
              };
          };
      };
  
      __overrides__ {
          int_pin = <&apds9960>,"interrupts:0";
          addr = <&apds9960>,"reg:0";
      };
  };
  

• Compilation to DTB (one of possible methods):

  git clone git://git.kernel.org/pub/scm/utils/dtc/dtc.git
  cd dtc
  make
  ./dtc i2c-apds9960.dts > i2c-apds9960.dtbo
  cp i2c-apds9960.dts /mnt/pi-zero/boot/overlays
  

• Update of the config.txt:

  dtoverlay=i2c-apds9960
  dtparam=int_pin=4 # For the case the pin needs to be different than in DTC
  

• Locate the device:

  # cat /sys/bus/iio/devices/iio\:device0/name
  apds9960