nixos/facter: add Intel IPU6 camera support

This adds automatic detection and configuration for Intel IPU6 cameras:

This is particularly useful for modern Intel laptops (11th-14th gen) with
integrated webcams that require the intel-ipu6 drivers. Auto-configuration
eliminates manual setup for these specialized devices.

Builds on PR #463457 (input peripherals).
Part of incremental upstreaming from nixos-facter-modules.

nixos/modules/hardware/facter/camera/default.nix

@@ -0,0 +1,3 @@
+{
+  imports = [ ./ipu6.nix ];
+}

nixos/modules/hardware/facter/camera/ipu6-devices.json

@@ -0,0 +1,3 @@
+{
+    "8086:9A19:17AA:508B/0004-0080-0001": true
+}

nixos/modules/hardware/facter/camera/ipu6.nix

@@ -0,0 +1,115 @@
+{ config, lib, ... }:
+let
+  inherit (config.hardware.facter) report detected;
+  facterLib = import ../lib.nix lib;
+
+  isCpuGeneration =
+    _family: models:
+    facterLib.hasIntelCpu report
+    && lib.any (
+      actual: (actual.family or 0) == 6 && builtins.elem (actual.model or 0) models
+    ) report.hardware.cpu;
+
+  # Family model combinations have been looked up at https://en.wikichip.org/wiki/intel/cpuid
+  isTigerLake = isCpuGeneration 6 [
+    140 # Combination tested on actual hardware
+    141
+  ];
+
+  isAdlerLake = isCpuGeneration 6 [
+    151
+    154
+  ];
+
+  isRaptorLake = isCpuGeneration 6 [
+    183
+    186
+    190
+    191
+  ];
+
+  isMeteorLake = isCpuGeneration 6 [
+    170
+    171
+    172
+  ];
+
+  devices = builtins.fromJSON (builtins.readFile ./ipu6-devices.json);
+  isCameraSupported =
+    let
+      default = {
+        value = 0;
+      };
+    in
+    lib.any (
+      {
+        base_class ? default,
+        sub_class ? default,
+        vendor ? default,
+        sub_vendor ? default,
+        device ? default,
+        sub_device ? default,
+        revision ? default,
+        bus_type ? {
+          name = "";
+        },
+        ...
+      }:
+      let
+        baseClassHex = facterLib.toZeroPaddedHex base_class.value;
+        subClassHex = facterLib.toZeroPaddedHex sub_class.value;
+        vendorHex = facterLib.toZeroPaddedHex vendor.value;
+        subVendorHex = facterLib.toZeroPaddedHex sub_vendor.value;
+        deviceHex = facterLib.toZeroPaddedHex device.value;
+        subDeviceHex = facterLib.toZeroPaddedHex sub_device.value;
+        revisionHex = facterLib.toZeroPaddedHex revision.value;
+      in
+      bus_type.name == "PCI"
+      && devices
+      ? "${vendorHex}:${deviceHex}:${subVendorHex}:${subDeviceHex}/${baseClassHex}-${subClassHex}-${revisionHex}"
+    );
+in
+{
+  options.hardware.facter.detected.camera.ipu6.enable =
+    let
+      cameraSupported =
+        isCameraSupported (report.hardware.unknown or [ ])
+        || isCameraSupported (report.hardware.pci or [ ]);
+
+      cpuSupported = lib.any (generation: generation) [
+        isTigerLake
+        isAdlerLake
+        isRaptorLake
+        isMeteorLake
+      ];
+    in
+    lib.mkEnableOption "webcams using ipu6 from Intel"
+    // {
+      default = cameraSupported && cpuSupported;
+      defaultText = "hardware dependent";
+    };
+
+  config.hardware.ipu6 = lib.mkIf detected.camera.ipu6.enable {
+    enable = true;
+    platform =
+      if isTigerLake then
+        "ipu6"
+      else if isAdlerLake || isRaptorLake then
+        "ipu6ep"
+      else if isMeteorLake then
+        "ipu6epmtl"
+      else
+        throw "Unexpected CPU generation for ipu6 detected.";
+  };
+
+  config.warnings =
+    let
+      isKernel6_16 = config.boot.kernelPackages.kernel.version == "6.16";
+      inherit (detected.camera) ipu6;
+    in
+    lib.optional (isKernel6_16 && ipu6.enable) ''
+      A regression bug can occur when combining ipu6 with kernel version 6.16.
+      This will most likely prevent your system from properely suspending or shutting down.
+      For more information see: https://github.com/intel/ipu6-drivers/issues/372
+    '';
+}

nixos/modules/hardware/facter/default.nix

@@ -6,6 +6,7 @@
 {
   imports = [
     ./bluetooth.nix
+    ./camera
     ./disk.nix
     ./fingerprint
     ./firmware.nix