lenovo/legion/16irx8h: add comprehensive audio and hardware support

Add full hardware configuration for Legion Pro 7 16IRX8H including:
- Realtek ALC287 + TAS2781 audio with proper kernel params
- Bluetooth LE Audio support via BlueZ settings
- Thermal management (thermald + ACPI fixes)
- Audio group permissions

Fixes audio issues where speakers wouldn't work due to missing
TAS2781 calibration reset and incorrect HDA model detection.

lenovo/legion/16irx8h/default.nix

@@ -19,21 +19,78 @@
     config.boot.kernelPackages.nvidia_x11
   ];
 
+  # Comprehensive audio fixes for Legion Pro 7 16IRX8H
+  # This model has both Realtek ALC287 and TAS2781 audio components
+  # The TAS2781 I2C codec binds to the HDA subsystem and requires special handling
+  boot.kernelParams = [
+    # Audio configuration
+    "snd_hda_intel.enable_msi=1"
+    # Legion-specific audio model (required until kernel quirk is upstreamed)
+    "snd_hda_intel.model=lenovo-legion-7i"
+    # TAS2781 calibration reset to handle CRC errors in factory calibration data
+    # This is a known issue on Legion laptops where the TAS2781 firmware has corrupted
+    # calibration values; resetting allows the codec to initialize with defaults
+    "snd_soc_tas2781.reset_calib=1"
+    # More aggressive TAS2781 fixes for Legion
+    "snd_soc_tas2781.tas2781_dev_id=0x6a"
+    "snd_hda_intel.single_cmd=1"
+    # Hardware fixes
+    "tsc=reliable" # Fix TSC ADJUST firmware bugs common on Legion laptops
+    # ACPI thermal management fixes for Legion BIOS issues
+    "acpi.debug_layer=0x2"
+    "acpi.debug_level=0x2"
+    "processor.ignore_ppc=1"
+  ];
+
+  # Additional audio configuration for Legion Pro 7
+  boot.extraModprobeConfig = ''
+    # Force specific Legion audio model for proper speaker routing
+    options snd-hda-intel model=lenovo-legion-7i single_cmd=1 probe_mask=1
+    # TAS2781 specific options
+    options snd-soc-tas2781-comlib reset_calib=1
+    options snd-hda-scodec-tas2781-i2c reset_calib=1
+  '';
+
+  # Hardware firmware support for Legion audio
+  hardware.enableRedistributableFirmware = lib.mkDefault true;
+
+  # Enable Bluetooth modules
+  boot.kernelModules = [
+    "bluetooth"
+    "btusb"
+  ];
+
   hardware = {
     nvidia = {
       modesetting.enable = lib.mkDefault true;
       powerManagement.enable = lib.mkDefault true;
-      #
       prime = {
         intelBusId = "PCI:00:02:0";
         nvidiaBusId = "PCI:01:00:0";
       };
     };
+
+    # Enable Bluetooth with Legion-optimized settings
+    bluetooth = {
+      enable = lib.mkDefault true;
+      powerOnBoot = lib.mkDefault false; # Save battery
+      settings = {
+        General = {
+          ControllerMode = "dual";
+          FastConnectable = "true";
+          Experimental = "true"; # Enable LE Audio features
+          KernelExperimental = "true"; # Enable ISO socket support
+        };
+      };
+    };
   };
 
-  # Cooling management
+  # Cooling management for Legion laptops
   services.thermald.enable = lib.mkDefault true;
 
+  # Audio group permissions
+  users.groups.audio = { };
+
   # √(2560² + 1600²) px / 16 in ≃ 189 dpi
   services.xserver.dpi = 189;
 }