Initialize USB controllers from Usb instead of Pci

src/hulk/pci.d

@@ -14,22 +14,28 @@ import hulk.list;
 
 struct Pci
 {
-    /* IO address for PCI configuration address. */
+    /** IO address for PCI configuration address. */
     enum IO_ADDR_CONFIG_ADDRESS = 0xCF8u;
 
-    /* IO address for PCI configuration data. */
+    /** IO address for PCI configuration data. */
     enum IO_ADDR_CONFIG_DATA = 0xCFCu;
 
+    /** Maximum number of devices on a bus. */
     enum MAX_DEVICES_PER_BUS = 32;
 
+    /** Maximum number of functions on a devices. */
     enum MAX_FUNCTIONS_PER_DEVICE = 8;
 
+    /** XHCI controller device type. */
+    enum XHCI_CONTROLLER = Type(0x0Cu, 0x03u, 0x30u);
+
     /**
      * PCI device address (bus number, device number, function number).
      */
     struct Address
     {
         uint address;
+        alias address this;
 
         this(ubyte bus_nr, ubyte device_nr, ubyte function_nr)
         {
@@ -67,6 +73,7 @@ struct Pci
     struct Type
     {
         uint type;
+        alias type this;
 
         this(ubyte class_id, ubyte subclass_id, ubyte interface_id)
         {
@@ -125,8 +132,6 @@ struct Pci
             {
                 map_memory_regions();
             }
-
-            spawn_device_instance();
         }
 
         private void map_memory_regions()
@@ -193,50 +198,6 @@ struct Pci
                 }
             }
         }
-
-        private void spawn_device_instance()
-        {
-            switch (config.class_id)
-            {
-            case SerialBusController.ID:
-                switch (config.subclass_id)
-                {
-                case SerialBusController.USBController.ID:
-                    switch (config.interface_id)
-                    {
-                    case SerialBusController.USBController.XHCIController.ID:
-                        XHCI.build(&this);
-                        break;
-
-                    default:
-                        break;
-                    }
-                    break;
-
-                default:
-                    break;
-                }
-                break;
-
-            default:
-                break;
-            }
-        }
-    }
-
-    struct SerialBusController
-    {
-        enum ID = 0x0Cu;
-
-        struct USBController
-        {
-            enum ID = 0x03u;
-
-            struct XHCIController
-            {
-                enum ID = 0x30u;
-            }
-        }
     }
 
     /**