api: uart: Add new asynchronous UART API.

Added new UART API, that allows for longer transmissions, leaves
IRQ handling on driver side and allows for DMA usage.

Signed-off-by: Mieszko Mierunski <[email protected]>

Author: Mierunski

drivers/serial/Kconfig

@@ -28,12 +28,19 @@ config SERIAL_SUPPORT_INTERRUPT
 	  This is an option to be enabled by individual serial driver
 	  to signal that the driver and hardware supports interrupts.
 
+config UART_ASYNC_API
+	bool "Enable new asynchronous UART API [EXPERIMENTAL]"
+	help
+	  This option enables new asynchronous UART API.
+
+if UART_ASYNC_API=n
 config UART_INTERRUPT_DRIVEN
 	bool "Enable UART Interrupt support"
 	depends on SERIAL_SUPPORT_INTERRUPT
 	help
 	  This option enables interrupt support for UART allowing console
 	  input and other UART based drivers.
+endif
 
 config UART_LINE_CTRL
 	bool "Enable Serial Line Control API"