nixos/facetimehd: add option hardware.facetimehd.withCalibration

The new option (disabled by default) pulls in the experimental sensor
calibration files for the Facetime HD camera. These will also be pulled
in by hardware.enableAllFirmware.

nixos/modules/hardware/all-firmware.nix

@@ -84,7 +84,10 @@ in {
         b43Firmware_6_30_163_46
         b43FirmwareCutter
         xow_dongle-firmware
-      ] ++ optional pkgs.stdenv.hostPlatform.isx86 facetimehd-firmware;
+      ] ++ optionals pkgs.stdenv.hostPlatform.isx86 [
+        facetimehd-calibration
+        facetimehd-firmware
+      ];
     })
     (mkIf cfg.wirelessRegulatoryDatabase {
       hardware.firmware = [ pkgs.wireless-regdb ];

nixos/modules/hardware/video/webcam/facetimehd.nix

@@ -14,6 +14,18 @@ in
 
   options.hardware.facetimehd.enable = mkEnableOption "facetimehd kernel module";
 
+  options.hardware.facetimehd.withCalibration = mkOption {
+    default = false;
+    example = true;
+    type = types.bool;
+    description = ''
+      Whether to include sensor calibration files for facetimehd.
+      This makes colors look much better but is experimental, see
+      <link xlink:href="https://github.com/patjak/facetimehd/wiki/Extracting-the-sensor-calibration-files"/>
+      for details.
+    '';
+  };
+
   config = mkIf cfg.enable {
 
     assertions = singleton {
@@ -27,7 +39,8 @@ in
 
     boot.extraModulePackages = [ kernelPackages.facetimehd ];
 
-    hardware.firmware = [ pkgs.facetimehd-firmware ];
+    hardware.firmware = [ pkgs.facetimehd-firmware ]
+      ++ optional cfg.withCalibration pkgs.facetimehd-calibration;
 
     # unload module during suspend/hibernate as it crashes the whole system
     powerManagement.powerDownCommands = ''