PMW3610 driver implementation for ZMK with at least Zephyr 3.5

This work is based on ufan's implementation of the driver.

Installation

Only GitHub actions builds are covered here. Local builds are different for each user, therefore it's not possible to cover all cases.

Include this project on your ZMK's west manifest in config/west.yml:

manifest:
  remotes:
    - name: zmkfirmware
      url-base: https://github.com/petejohanson
    - name: inorichi
      url-base: https://github.com/inorichi
  projects:
    - name: zmk
      remote: zmkfirmware
      revision: feat/pointers-move-scroll
      import: app/west.yml
    - name: zmk-pmw3610-driver
      remote: inorichi
      revision: main
  self:
    path: config

Then, edit your build.yml to look like this, 3.5 is now on main:

on: [workflow_dispatch]

jobs:
  build:
    uses: zmkfirmware/zmk/.github/workflows/build-user-config.yml@main

Now, update your board.overlay adding the necessary bits (update the pins for your board accordingly):

&pinctrl {
    spi0_default: spi0_default {
        group1 {
            psels = <NRF_PSEL(SPIM_SCK, 0, 8)>,
                <NRF_PSEL(SPIM_MOSI, 0, 17)>,
                <NRF_PSEL(SPIM_MISO, 0, 17)>;
        };
    };

    spi0_sleep: spi0_sleep {
        group1 {
            psels = <NRF_PSEL(SPIM_SCK, 0, 8)>,
                <NRF_PSEL(SPIM_MOSI, 0, 17)>,
                <NRF_PSEL(SPIM_MISO, 0, 17)>;
            low-power-enable;
        };
    };
};

&spi0 {
    status = "okay";
    compatible = "nordic,nrf-spim";
    pinctrl-0 = <&spi0_default>;
    pinctrl-1 = <&spi0_sleep>;
    pinctrl-names = "default", "sleep";
    cs-gpios = <&gpio0 20 GPIO_ACTIVE_LOW>;

    trackball: trackball@0 {
        status = "okay";
        compatible = "pixart,pmw3610";
        reg = <0>;
        spi-max-frequency = <2000000>;
        irq-gpios = <&gpio0 6 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;

        /*   optional features   */
        // snipe-layers = <1>;
        // scroll-layers = <2 3>;
        // automouse-layer = <4>;
    };
};

/ {
  trackball_listener {
    compatible = "zmk,input-listener";
    device = <&trackball>;

  };
};

Now enable the driver config in your board.config file (read the Kconfig file to find out all possible options):

CONFIG_SPI=y
CONFIG_INPUT=y
CONFIG_ZMK_MOUSE=y
CONFIG_PMW3610=y