1 files changed, 28 insertions, 8 deletions
diff --git a/ArmPlatformPkg/Include/Drivers/PL011Uart.h b/ArmPlatformPkg/Include/Drivers/PL011Uart.h
index f8e4a083aa..6675cefeb3 100644
--- a/ArmPlatformPkg/Include/Drivers/PL011Uart.h
+++ b/ArmPlatformPkg/Include/Drivers/PL011Uart.h
@@ -134,20 +134,40 @@ PL011UartSetControl (
   );
 
 /**
-  Get the serial device control bits.
 
-  @param  UartBase                The base address of the PL011 UART.
-  @param  Control                 Control signals read from the serial device.
-
-  @retval EFI_SUCCESS             The control bits were read from the serial device.
-  @retval EFI_DEVICE_ERROR        The serial device is not functioning correctly.
+  Retrieve the status of the control bits on a serial device.
+
+  @param[in]   UartBase  UART registers base address
+  @param[out]  Control   Status of the control bits on a serial device :
+
+                         . EFI_SERIAL_DATA_CLEAR_TO_SEND, EFI_SERIAL_DATA_SET_READY,
+                           EFI_SERIAL_RING_INDICATE, EFI_SERIAL_CARRIER_DETECT,
+                           EFI_SERIAL_REQUEST_TO_SEND, EFI_SERIAL_DATA_TERMINAL_READY
+                           are all related to the DTE (Data Terminal Equipment) and
+                           DCE (Data Communication Equipment) modes of operation of
+                           the serial device.
+                         . EFI_SERIAL_INPUT_BUFFER_EMPTY : equal to one if the receive
+                           buffer is empty, 0 otherwise.
+                         . EFI_SERIAL_OUTPUT_BUFFER_EMPTY : equal to one if the transmit
+                           buffer is empty, 0 otherwise.
+                         . EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE : equal to one if the
+                           hardware loopback is enabled (the ouput feeds the receive
+                           buffer), 0 otherwise.
+                         . EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE : equal to one if a
+                           loopback is accomplished by software, 0 otherwise.
+                         . EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE : equal to one if the
+                           hardware flow control based on CTS (Clear To Send) and RTS
+                           (Ready To Send) control signals is enabled, 0 otherwise.
+
+
+  @retval RETURN_SUCCESS  The control bits were read from the serial device.
 
 **/
 RETURN_STATUS
 EFIAPI
 PL011UartGetControl (
-    IN UINTN                    UartBase,
-    OUT UINT32                  *Control
+  IN UINTN     UartBase,
+  OUT UINT32  *Control
   );
 
 /**