bitspire/deploy/nixos/hardware/upboard.nix

# Tejo (UP Board / UP4000) Hardware Configuration
# Intel Atom/Celeron boards used in Lamassu Tejo ATM machines.
# Supports both UP Board and UP4000 variants — udev rules for both
# are included since they match different kernel paths and don't conflict.
#
# Serial port mapping:
#   ttyJ4 = Printer (Nippon NP-2511D-2)
#   ttyJ5 = Validator (iVizion, ID003 protocol)
#   ttyJ7 = Dispenser (Fujitsu F53/F56)

{ config, lib, pkgs, ... }:

{
  boot = {
    loader = {
      systemd-boot.enable = true;
      efi.canTouchEfiVariables = true;
      timeout = 3;
    };

    initrd.availableKernelModules = [
      "xhci_pci"
      "ahci"
      "usb_storage"
      "sd_mod"
      "sdhci_pci"
      "sdhci-acpi" # UP Board sintra: eMMC controller is ACPI-enumerated, not PCI
      "mmc_block" # creates /dev/mmcblk* block-device nodes
      "i915"
    ];

    # Force-load the eMMC stack in stage 1 so root-by-label resolves before
    # the kernel hands off to switch_root. Without this, initramfs panics
    # with "An error occurred in stage 1 of the boot process" because
    # /dev/disk/by-label/nixos never materialises in time.
    initrd.kernelModules = [
      "sdhci-acpi"
      "mmc_block"
    ];

    kernelModules = [
      "kvm-intel"
      "i2c-dev"
      "spi-dev"
      "usbserial" # USB-to-serial adapters
      "ftdi_sio" # FTDI USB serial
      "cp210x" # CP210x USB serial
    ];

    kernelParams = [
      "i915.enable_psr=0"
      # NOTE: do NOT route the kernel console through ttyS4 on Sintra.
      # ttyS4 is the SoC's MMIO 16550A (the only real UART besides the
      # legacy ttyS0 at I/O 0x3f8) and is wired to the Fujitsu F56
      # dispenser's RS-232 header on Sintra. Holding it as console
      # prevents userspace from opening it at 9600 baud and HAL fails
      # with "Input/output error setting custom baud rate of 9600".
      # If you want serial debug, point console at ttyS0 instead.
      "console=tty0"
      "quiet"
      "splash"
    ];
  };

  # Disk layout: GPT with ESP + ext4 root (eMMC on UP Board).
  # Labels match what make-disk-image.nix with partitionTableType="efi"
  # produces — ESP for the FAT partition, nixos for the ext4 root. We
  # previously expected `by-label/boot` here and had to manually
  # `fatlabel` the partition post-flash; aligning the label avoids
  # that hand-step on future re-flashes. (douro.nix already uses ESP.)
  fileSystems."/" = {
    device = "/dev/disk/by-label/nixos";
    fsType = "ext4";
  };

  fileSystems."/boot" = {
    device = "/dev/disk/by-label/ESP";
    fsType = "vfat";
  };

  hardware = {
    graphics = {
      enable = true;
      extraPackages = with pkgs; [
        intel-media-driver
        libva-vdpau-driver
        libvdpau-va-gl
      ];
    };
    enableRedistributableFirmware = true;
    cpu.intel.updateMicrocode = true;
  };

  powerManagement = {
    enable = true;
    cpuFreqGovernor = "performance";
  };

  # Disable suspend/hibernate for kiosk
  systemd.targets = {
    sleep.enable = false;
    suspend.enable = false;
    hibernate.enable = false;
    hybrid-sleep.enable = false;
  };

  # Serial port permissions + tejo-specific symlinks
  services.udev.extraRules = lib.mkAfter ''
    # Generic serial port permissions
    KERNEL=="ttyS[0-9]*", MODE="0666"
    KERNEL=="ttyUSB[0-9]*", MODE="0666"
    KERNEL=="ttyACM[0-9]*", MODE="0666"

    # ── Tejo serial port symlinks ──────────────────────────────────────
    # Both UP Board and UP4000 rules included (match different kernel paths)

    # Printer (ttyJ4)
    KERNELS=="1-7.2:1.0", SYMLINK+="ttyJ4"
    KERNEL=="ttyUSB0", SYMLINK+="ttyJ4"

    # Validator (ttyJ5)
    KERNELS=="1-7.3:1.0", SYMLINK+="ttyJ5"
    KERNEL=="ttyUSB1", SYMLINK+="ttyJ5"

    # Dispenser (ttyJ7).
    # ttyS1 / ttyS5 cover earlier UP Board variants where the dispenser
    # lands on those kernel-enumerated serial nodes; ttyS4 covers the
    # Sintra (UP Board Atom/Apollo Lake) where the dispenser is wired
    # to the SoC's MMIO UART. Whichever device actually exists at
    # runtime gets the ttyJ7 symlink.
    KERNEL=="ttyS1", SYMLINK+="ttyJ7"
    KERNEL=="ttyS4", SYMLINK+="ttyJ7"
    KERNEL=="ttyS5", SYMLINK+="ttyJ7"

    # Legacy ttyAMA0 alias
    SUBSYSTEM=="tty", KERNEL=="ttyS1", SYMLINK+="ttyAMA0", GROUP="dialout"

    # ── Camera devices ─────────────────────────────────────────────────
    SUBSYSTEM=="video4linux", ATTR{index}=="0", KERNELS=="1-5", ATTRS{idVendor}=="0ac8", ATTRS{idProduct}=="0345", SYMLINK+="video-scan"
    SUBSYSTEM=="video4linux", ATTR{index}=="0", KERNELS=="1-2", ATTRS{idVendor}=="0ac8", ATTRS{idProduct}=="0345", SYMLINK+="video-scan"
    SUBSYSTEM=="video4linux", ATTR{index}=="0", KERNELS=="1-6", ATTRS{idVendor}=="0ac8", ATTRS{idProduct}=="0345", SYMLINK+="video-front"
    SUBSYSTEM=="video4linux", ATTR{index}=="0", KERNELS=="1-3", ATTRS{idVendor}=="0ac8", ATTRS{idProduct}=="0345", SYMLINK+="video-front"

    # ── LED SPI / peripherals ──────────────────────────────────────────
    KERNEL=="spidev1.0", SYMLINK+="ledspi"
    KERNEL=="spidev2.0", SYMLINK+="ledspi"
    SUBSYSTEM=="spidev", GROUP="spi", MODE="0660"
    SUBSYSTEM=="i2c-dev", GROUP="i2c", MODE="0660"
    SUBSYSTEM=="leds", KERNEL=="upboard:*", ACTION=="add|change", RUN+="${pkgs.findutils}/bin/find /sys$devpath -type f -exec ${pkgs.coreutils}/bin/chmod g+u {} + -exec ${pkgs.coreutils}/bin/chown :leds {} +"

    # Disable USB autosuspend (prevents serial adapters from sleeping)
    ACTION=="add", SUBSYSTEM=="usb", TEST=="power/control", ATTR{power/control}="on"
  '';
}