usb moved cs_interface descriptor to global descriptors

Author: itzandroidtab

klib/usb/cdc/descriptor.hpp

@@ -49,19 +49,7 @@ namespace klib::usb::cdc::detail {
      *
      */
     template <typename Base, subtype SubType>
-    struct functional {
-        // size of the descriptor
-        const uint8_t bFunctionLength = sizeof(Base);
-
-        // descriptor type (CS_INTERFACE)
-        const descriptor::descriptor_type bDescriptorType = descriptor::descriptor_type::cs_interface;
-
-        // header functional descriptor subtype
-        const uint8_t bDescriptorSubtype = static_cast<uint8_t>(SubType);
-    };
-
-    // make sure the size is correct
-    static_assert(sizeof(functional<uint8_t, subtype::header>) == 0x03, "Cdc functional descriptor size is wrong");
+    struct functional: public descriptor::cs_interface<Base, static_cast<uint8_t>(SubType)> {};
 }
 
 namespace klib::usb::cdc {

klib/usb/descriptor.hpp

@@ -436,6 +436,25 @@ namespace klib::usb::descriptor {
     };
 
     static_assert(sizeof(interface_association) == 8, "Interface association descriptor is not 8 bytes in length");
+
+    /**
+     * @brief Base for all the class specific interface descriptors
+     *
+     */
+    template <typename Base, uint8_t SubType>
+    struct cs_interface {
+        // size of the descriptor
+        const uint8_t bFunctionLength = sizeof(Base);
+
+        // the device class specific descriptor type
+        const descriptor_type bDescriptorType = descriptor_type::cs_interface;
+
+        // header functional descriptor subtype
+        const uint8_t bDescriptorSubtype = static_cast<uint8_t>(SubType);
+    };
+
+    // make sure the size is correct
+    static_assert(sizeof(cs_interface<uint8_t, 0x00>) == 0x03, "Class specific base descriptor size is wrong");
 }
 
 // release the old pack so the rest of the structs are not