begin USB refactor with package machine/usb2

src/machine/machine_mimxrt1062_usb.go

@@ -0,0 +1,29 @@
+// +build mimxrt1062
+
+// Compatibility wrapper for legacy type USBCDC, which provides USB CDC-ACM
+// device class emulation for serial UART communication.
+// This functionality is being replaced by a platform-agnostic type usb.UART in
+// package "machine/usb".
+
+package machine
+
+import (
+	"machine/usb2"
+)
+
+// USBCDC is the legacy TinyGo type used to implement USB CDC-ACM device class
+// emulation for serial UART communication. It is retained here as a temporary
+// wrapper for type usb.UART from new package "machine/usb", which is still in
+// active development. Once that package has stabilized a bit, this type should
+// be removed and usb.UART should be used directly instead.
+type USBCDC struct {
+	port uint8
+	buff *RingBuffer
+	uart usb2.UART
+}
+
+// Configure the embedded usb.UART with our receiver's settings and the given
+// UART configuration. This provides compatibility with machine.UART.
+func (cdc *USBCDC) Configure(config UARTConfig) {
+	cdc.uart.Configure(usb2.UARTConfig{BaudRate: config.BaudRate})
+}