alsa-ucm-conf: split the patched alsa confs out into their own package

hosts/common/programs/alsa-ucm-conf/default.nix

@@ -16,38 +16,18 @@ in
 
     # upstream alsa ships with PinePhone audio configs, but they don't actually produce sound.
     # see: <https://github.com/alsa-project/alsa-ucm-conf/pull/134>
-    # these audio files come from some revision of:
-    # - <https://gitlab.manjaro.org/manjaro-arm/packages/community/phosh/alsa-ucm-pinephone>
     #
-    # alternative to patching is to plumb `ALSA_CONFIG_UCM2 = "${./ucm2}"` environment variable into the relevant places
-    # e.g. `systemd.services.pulseaudio.environment`.
-    # that leaves more opportunity for gaps (i.e. missing a service),
-    # on the other hand this method causes about 500 packages to be rebuilt (including qt5 and webkitgtk).
-    #
-    # note that with these files, the following audio device support:
-    # - headphones work.
-    # - "internal earpiece" works.
-    # - "internal speaker" doesn't work (but that's probably because i broke the ribbon cable)
-    # - "analog output" doesn't work.
-    packageUnwrapped = pkgs.alsa-ucm-conf.overrideAttrs (upstream: {
-      postPatch = (upstream.postPatch or "") + ''
-        cp ${./ucm2/PinePhone}/* ucm2/Allwinner/A64/PinePhone/
+    # we can substitute working UCM conf in two ways:
+    # 1. nixpkgs' override for the `alsa-ucm-conf` package
+    #   - that forces a rebuild of ~500 packages (including webkitgtk).
+    # 2. set ALSA_CONFIG_UCM2 = /path/to/ucm2 in the relevant places
+    #   - e.g. pulsewire service.
+    #   - easy to miss places, though.
+    packageUnwrapped = pkgs.alsa-ucm-pinephone-manjaro.override {
+      inherit (cfg.config) preferEarpiece;
+    };
 
-        # fix the self-contained ucm files i source from to have correct path within the alsa-ucm-conf source tree
-        substituteInPlace ucm2/Allwinner/A64/PinePhone/PinePhone.conf \
-          --replace-fail 'HiFi.conf' '/Allwinner/A64/PinePhone/HiFi.conf'
-        substituteInPlace ucm2/Allwinner/A64/PinePhone/PinePhone.conf \
-          --replace-fail 'VoiceCall.conf' '/Allwinner/A64/PinePhone/VoiceCall.conf'
-      '' + lib.optionalString cfg.config.preferEarpiece ''
-        # decrease the priority of the internal speaker so that sounds are routed
-        # to the earpiece by default.
-        # this is just personal preference.
-        substituteInPlace ucm2/Allwinner/A64/PinePhone/{HiFi.conf,VoiceCall.conf} \
-          --replace-fail 'PlaybackPriority 300' 'PlaybackPriority 100'
-      '';
-    });
-
-    sandbox.enable = false;  #< only provides #out/share/alsa
+    sandbox.enable = false;  #< only provides $out/share/alsa
 
     # alsa-lib package only looks in its $out/share/alsa to find runtime config data, by default.
     # but ALSA_CONFIG_UCM2 is an env var that can override that.

hosts/common/programs/assorted.nix

@@ -829,6 +829,8 @@ in
     smartmontools.sandbox.autodetectCliPaths = "existing";
     smartmontools.sandbox.capabilities = [ "sys_rawio" ];
 
+    # snapshot camera, based on libcamera
+    # TODO: enable dma heaps for more efficient buffer sharing: <https://gitlab.com/postmarketOS/pmaports/-/issues/2789>
     snapshot = {};
 
     sops.sandbox.method = "bwrap";  # TODO:sandbox: untested

pkgs/additional/alsa-ucm-pinephone-manjaro/default.nix

@@ -0,0 +1,28 @@
+# these audio files come from some revision of:
+# - <https://gitlab.manjaro.org/manjaro-arm/packages/community/phosh/alsa-ucm-pinephone>
+# note that with these files, the following audio device support:
+# - headphones work.
+# - "internal earpiece" works.
+# - "internal speaker" doesn't work (but that's probably because i broke the ribbon cable)
+# - "analog output" doesn't work.
+{ alsa-ucm-conf
+, lib
+, preferEarpiece ? false
+}:
+alsa-ucm-conf.overrideAttrs (upstream: {
+  postPatch = (upstream.postPatch or "") + ''
+    cp ${./ucm2/PinePhone}/* ucm2/Allwinner/A64/PinePhone/
+
+    # fix the self-contained ucm files i source from to have correct path within the alsa-ucm-conf source tree
+    substituteInPlace ucm2/Allwinner/A64/PinePhone/PinePhone.conf \
+      --replace-fail 'HiFi.conf' '/Allwinner/A64/PinePhone/HiFi.conf'
+    substituteInPlace ucm2/Allwinner/A64/PinePhone/PinePhone.conf \
+      --replace-fail 'VoiceCall.conf' '/Allwinner/A64/PinePhone/VoiceCall.conf'
+  '' + lib.optionalString preferEarpiece ''
+    # decrease the priority of the internal speaker so that sounds are routed
+    # to the earpiece by default.
+    # this is just personal preference.
+    substituteInPlace ucm2/Allwinner/A64/PinePhone/{HiFi.conf,VoiceCall.conf} \
+      --replace-fail 'PlaybackPriority 300' 'PlaybackPriority 100'
+  '';
+})

pkgs/default.nix

@@ -20,6 +20,7 @@ let
     sane-lib = import ../modules/lib final';
 
     ### ADDITIONAL PACKAGES
+    alsa-ucm-pinephone-manjaro = callPackage ./additional/alsa-ucm-pinephone-manjaro { };
     blast-ugjka = callPackage ./additional/blast-ugjka { };
     bootpart-uefi-x86_64 = callPackage ./additional/bootpart-uefi-x86_64 { };
     cargoDocsetHook = callPackage ./additional/cargo-docset/hook.nix { };