ArmPlatformPkg/ArmJunoPkg: ACPI PCI Support

[mirror_edk2.git] / EmbeddedPkg / Include / Library / SerialPortExtLib.h

diff --git a/EmbeddedPkg/Include/Library/SerialPortExtLib.h b/EmbeddedPkg/Include/Library/SerialPortExtLib.h
index 29a7537b1519132d723dbeba7cf675e0e4fbe683..0d0abb35ff54320a9c95e08f92be1bb3f58e4b09 100644 (file)
--- a/EmbeddedPkg/Include/Library/SerialPortExtLib.h
+++ b/EmbeddedPkg/Include/Library/SerialPortExtLib.h
@@ -1,6 +1,16 @@
 /** @file\r
 \r
-  Copyright (c) 2012, ARM Ltd. All rights reserved.\r
+  Serial I/O port control interface extension.\r
+\r
+  This library provides an extension to the library providing common\r
+  serial I/O port functions that is defined in MdePkg. The aim is to\r
+  provide more control over the functionalities of a serial port. The\r
+  extension covers all the needs of the UEFI Serial I/O Protocol.\r
+  Though, its use is not restricted to the UEFI Serial I/O Protocol.\r
+  It could for example be used in the PEI phase of the boot sequence\r
+  as well.\r
+\r
+  Copyright (c) 2012 - 2014, ARM Ltd. All rights reserved.\r
 \r
   This program and the accompanying materials\r
   are licensed and made available under the terms and conditions of the BSD License\r
@@ -19,30 +29,70 @@
 #include <Protocol/SerialIo.h>\r
 \r
 /**\r
-  Set the serial device control bits.\r
 \r
-  @return    Always return EFI_UNSUPPORTED.\r
+  Assert or deassert the control signals on a serial port.\r
+  The following control signals are set according their bit settings :\r
+  . Request to Send\r
+  . Data Terminal Ready\r
+\r
+  @param[in]  Control  The following bits are taken into account :\r
+                       . EFI_SERIAL_REQUEST_TO_SEND : assert/deassert the\r
+                         "Request To Send" control signal if this bit is\r
+                         equal to one/zero.\r
+                       . EFI_SERIAL_DATA_TERMINAL_READY : assert/deassert\r
+                         the "Data Terminal Ready" control signal if this\r
+                         bit is equal to one/zero.\r
+                       . EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE : enable/disable\r
+                         the hardware loopback if this bit is equal to\r
+                         one/zero.\r
+                       . EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE : not supported.\r
+                       . EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE : enable/\r
+                         disable the hardware flow control based on CTS (Clear\r
+                         To Send) and RTS (Ready To Send) control signals.\r
+\r
+  @retval  RETURN_SUCCESS      The new control bits were set on the serial device.\r
+  @retval  RETURN_UNSUPPORTED  The serial device does not support this operation.\r
 \r
 **/\r
 RETURN_STATUS\r
 EFIAPI\r
 SerialPortSetControl (\r
-  IN UINT32                   Control\r
+  IN UINT32  Control\r
   );\r
 \r
 /**\r
-  Get the serial device control bits.\r
-\r
-  @param  Control                 Control signals read from the serial device.\r
 \r
-  @retval EFI_SUCCESS             The control bits were read from the serial device.\r
-  @retval EFI_DEVICE_ERROR        The serial device is not functioning correctly.\r
+  Retrieve the status of the control bits on a serial device.\r
+\r
+  @param[out]  Control  Status of the control bits on a serial device :\r
+\r
+                        . EFI_SERIAL_DATA_CLEAR_TO_SEND, EFI_SERIAL_DATA_SET_READY,\r
+                          EFI_SERIAL_RING_INDICATE, EFI_SERIAL_CARRIER_DETECT,\r
+                          EFI_SERIAL_REQUEST_TO_SEND, EFI_SERIAL_DATA_TERMINAL_READY\r
+                          are all related to the DTE (Data Terminal Equipment) and\r
+                          DCE (Data Communication Equipment) modes of operation of\r
+                          the serial device.\r
+                        . EFI_SERIAL_INPUT_BUFFER_EMPTY : equal to one if the receive\r
+                          buffer is empty, 0 otherwise.\r
+                        . EFI_SERIAL_OUTPUT_BUFFER_EMPTY : equal to one if the transmit\r
+                          buffer is empty, 0 otherwise.\r
+                        . EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE : equal to one if the\r
+                          hardware loopback is enabled (the ouput feeds the receive\r
+                          buffer), 0 otherwise.\r
+                        . EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE : equal to one if a\r
+                          loopback is accomplished by software, 0 otherwise.\r
+                        . EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE : equal to one if the\r
+                          hardware flow control based on CTS (Clear To Send) and RTS\r
+                          (Ready To Send) control signals is enabled, 0 otherwise.\r
+\r
+  @retval RETURN_SUCCESS       The control bits were read from the serial device.\r
+  @retval RETURN_DEVICE_ERROR  The serial device is not functioning correctly.\r
 \r
 **/\r
 RETURN_STATUS\r
 EFIAPI\r
 SerialPortGetControl (\r
-  OUT UINT32                  *Control\r
+  OUT UINT32  *Control\r
   );\r
 \r
 /**\r