https://bugzilla.tianocore.org/show_bug.cgi?id=553 Remove left shift of negative values that always evaluate to 0 to address build errors from the llvm/clang compiler used in the XCODE5 tool chain. Clang rightfully complains about left-shifting ~DLAB. DLAB is #defined as 0x01 (an "int"), hence ~DLAB has value (-2) on all edk2 platforms. Left-shifting a negative int is undefined behavior. Rather than replacing ~DLAB with ~(UINT32)DLAB, realize that the nonzero bits of (~(UINT32)DLAB << 7) would all be truncated away in the final conversion to UINT8 anyway. So just remove (~DLAB << 7). Cc: Ruiyu Ni <ruiyu.ni@intel.com> Cc: Andrew Fish <afish@apple.com> Cc: Laszlo Ersek <lersek@redhat.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
		
			
				
	
	
		
			490 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			490 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /** @file
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|   UART Serial Port library functions
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| 
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|   Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
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|   This program and the accompanying materials
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|   are licensed and made available under the terms and conditions of the BSD License
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|   which accompanies this distribution.  The full text of the license may be found at
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|   http://opensource.org/licenses/bsd-license.php
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| 
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|   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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|   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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| 
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| **/
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| 
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| #include <Base.h>
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| #include <Library/IoLib.h>
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| #include <Library/SerialPortLib.h>
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| 
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| //---------------------------------------------
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| // UART Register Offsets
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| //---------------------------------------------
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| #define BAUD_LOW_OFFSET         0x00
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| #define BAUD_HIGH_OFFSET        0x01
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| #define IER_OFFSET              0x01
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| #define LCR_SHADOW_OFFSET       0x01
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| #define FCR_SHADOW_OFFSET       0x02
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| #define IR_CONTROL_OFFSET       0x02
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| #define FCR_OFFSET              0x02
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| #define EIR_OFFSET              0x02
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| #define BSR_OFFSET              0x03
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| #define LCR_OFFSET              0x03
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| #define MCR_OFFSET              0x04
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| #define LSR_OFFSET              0x05
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| #define MSR_OFFSET              0x06
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| 
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| //---------------------------------------------
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| // UART Register Bit Defines
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| //---------------------------------------------
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| #define LSR_TXRDY               0x20
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| #define LSR_RXDA                0x01
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| #define DLAB                    0x01
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| #define MCR_DTRC                0x01
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| #define MCR_RTS                 0x02
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| #define MSR_CTS                 0x10
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| #define MSR_DSR                 0x20
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| #define MSR_RI                  0x40
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| #define MSR_DCD                 0x80
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| 
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| //---------------------------------------------
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| // UART Settings
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| //---------------------------------------------
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| UINT16  gUartBase = 0x3F8;
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| UINTN   gBps      = 115200;
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| UINT8   gData     = 8;
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| UINT8   gStop     = 1;
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| UINT8   gParity   = 0;
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| UINT8   gBreakSet = 0;
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| 
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| /**
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|   Initialize the serial device hardware.
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|   
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|   If no initialization is required, then return RETURN_SUCCESS.
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|   If the serial device was successfully initialized, then return RETURN_SUCCESS.
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|   If the serial device could not be initialized, then return RETURN_DEVICE_ERROR.
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|   
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|   @retval RETURN_SUCCESS        The serial device was initialized.
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|   @retval RETURN_DEVICE_ERROR   The serail device could not be initialized.
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| 
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| **/
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| RETURN_STATUS
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| EFIAPI
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| SerialPortInitialize (
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|   VOID
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|   )
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| {
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|   UINTN  Divisor;
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|   UINT8  OutputData;
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|   UINT8  Data;
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| 
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|   //
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|   // Map 5..8 to 0..3
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|   //
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|   Data = (UINT8) (gData - (UINT8) 5);
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| 
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|   //
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|   // Calculate divisor for baud generator
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|   //
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|   Divisor = 115200 / gBps;
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|   
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|   //
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|   // Set communications format
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|   //
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|   OutputData = (UINT8) ((DLAB << 7) | (gBreakSet << 6) | (gParity << 3) | (gStop << 2) | Data);
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|   IoWrite8 (gUartBase + LCR_OFFSET, OutputData);
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| 
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|   //
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|   // Configure baud rate
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|   //
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|   IoWrite8 (gUartBase + BAUD_HIGH_OFFSET, (UINT8) (Divisor >> 8));
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|   IoWrite8 (gUartBase + BAUD_LOW_OFFSET, (UINT8) (Divisor & 0xff));
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| 
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|   //
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|   // Switch back to bank 0
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|   //
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|   OutputData = (UINT8) ( (gBreakSet << 6) | (gParity << 3) | (gStop << 2) | Data);
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|   IoWrite8 (gUartBase + LCR_OFFSET, OutputData);
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| 
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|   return RETURN_SUCCESS;
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| }
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| 
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| /**
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|   Write data from buffer to serial device. 
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|  
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|   Writes NumberOfBytes data bytes from Buffer to the serial device.  
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|   The number of bytes actually written to the serial device is returned.
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|   If the return value is less than NumberOfBytes, then the write operation failed.
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| 
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|   If Buffer is NULL, then ASSERT(). 
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| 
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|   If NumberOfBytes is zero, then return 0.
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| 
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|   @param  Buffer           Pointer to the data buffer to be written.
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|   @param  NumberOfBytes    Number of bytes to written to the serial device.
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| 
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|   @retval 0                NumberOfBytes is 0.
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|   @retval >0               The number of bytes written to the serial device.  
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|                            If this value is less than NumberOfBytes, then the write operation failed.
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| 
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| **/
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| UINTN
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| EFIAPI
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| SerialPortWrite (
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|   IN UINT8     *Buffer,
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|   IN UINTN     NumberOfBytes
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| )
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| {
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|   UINTN  Result;
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|   UINT8  Data;
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| 
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|   if (Buffer == NULL) {
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|     return 0;
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|   }
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| 
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|   Result = NumberOfBytes;
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| 
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|   while ((NumberOfBytes--) != 0) {
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|     //
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|     // Wait for the serail port to be ready.
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|     //
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|     do {
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|       Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);
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|     } while ((Data & LSR_TXRDY) == 0);
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|     IoWrite8 ((UINT16) gUartBase, *Buffer++);
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|   }
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| 
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|   return Result;
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| }
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| 
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| 
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| /**
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|   Reads data from a serial device into a buffer.
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| 
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|   @param  Buffer           Pointer to the data buffer to store the data read from the serial device.
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|   @param  NumberOfBytes    Number of bytes to read from the serial device.
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| 
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|   @retval 0                NumberOfBytes is 0.
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|   @retval >0               The number of bytes read from the serial device.  
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|                            If this value is less than NumberOfBytes, then the read operation failed.
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| 
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| **/
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| UINTN
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| EFIAPI
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| SerialPortRead (
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|   OUT UINT8     *Buffer,
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|   IN  UINTN     NumberOfBytes
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| )
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| {
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|   UINTN  Result;
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|   UINT8  Data;
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| 
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|   if (NULL == Buffer) {
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|     return 0;
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|   }
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| 
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|   Result = NumberOfBytes;
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| 
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|   while ((NumberOfBytes--) != 0) {
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|     //
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|     // Wait for the serail port to be ready.
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|     //
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|     do {
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|       Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);
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|     } while ((Data & LSR_RXDA) == 0);
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| 
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|     *Buffer++ = IoRead8 ((UINT16) gUartBase);
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|   }
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| 
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|   return Result;
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| }
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| 
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| /**
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|   Polls a serial device to see if there is any data waiting to be read.
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| 
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|   Polls aserial device to see if there is any data waiting to be read.
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|   If there is data waiting to be read from the serial device, then TRUE is returned.
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|   If there is no data waiting to be read from the serial device, then FALSE is returned.
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| 
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|   @retval TRUE             Data is waiting to be read from the serial device.
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|   @retval FALSE            There is no data waiting to be read from the serial device.
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| 
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| **/
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| BOOLEAN
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| EFIAPI
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| SerialPortPoll (
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|   VOID
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|   )
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| {
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|   UINT8  Data;
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| 
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|   //
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|   // Read the serial port status.
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|   //
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|   Data = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);
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| 
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|   return (BOOLEAN) ((Data & LSR_RXDA) != 0);
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| }
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| 
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| /**
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|   Sets the control bits on a serial device.
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| 
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|   @param Control                Sets the bits of Control that are settable.
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| 
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|   @retval RETURN_SUCCESS        The new control bits were set on the serial device.
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|   @retval RETURN_UNSUPPORTED    The serial device does not support this operation.
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|   @retval RETURN_DEVICE_ERROR   The serial device is not functioning correctly.
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| 
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| **/
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| RETURN_STATUS
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| EFIAPI
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| SerialPortSetControl (
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|   IN UINT32 Control
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|   )
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| {
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|   UINT8 Mcr;
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| 
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|   //
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|   // First determine the parameter is invalid.
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|   //
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|   if ((Control & (~(EFI_SERIAL_REQUEST_TO_SEND | EFI_SERIAL_DATA_TERMINAL_READY))) != 0) {
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|     return RETURN_UNSUPPORTED;
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|   }
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| 
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|   //
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|   // Read the Modem Control Register.
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|   //
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|   Mcr = IoRead8 ((UINT16) gUartBase + MCR_OFFSET);
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|   Mcr &= (~(MCR_DTRC | MCR_RTS));
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| 
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|   if ((Control & EFI_SERIAL_DATA_TERMINAL_READY) == EFI_SERIAL_DATA_TERMINAL_READY) {
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|     Mcr |= MCR_DTRC;
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|   }
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| 
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|   if ((Control & EFI_SERIAL_REQUEST_TO_SEND) == EFI_SERIAL_REQUEST_TO_SEND) {
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|     Mcr |= MCR_RTS;
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|   }
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| 
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|   //
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|   // Write the Modem Control Register.
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|   //
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|   IoWrite8 ((UINT16) gUartBase + MCR_OFFSET, Mcr);
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| 
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|   return RETURN_SUCCESS;
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| }
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| 
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| /**
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|   Retrieve the status of the control bits on a serial device.
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| 
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|   @param Control                A pointer to return the current control signals from the serial device.
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| 
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|   @retval RETURN_SUCCESS        The control bits were read from the serial device.
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|   @retval RETURN_UNSUPPORTED    The serial device does not support this operation.
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|   @retval RETURN_DEVICE_ERROR   The serial device is not functioning correctly.
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| 
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| **/
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| RETURN_STATUS
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| EFIAPI
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| SerialPortGetControl (
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|   OUT UINT32 *Control
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|   )
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| {
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|   UINT8 Msr;
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|   UINT8 Mcr;
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|   UINT8 Lsr;
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| 
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|   *Control = 0;
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| 
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|   //
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|   // Read the Modem Status Register.
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|   //
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|   Msr = IoRead8 ((UINT16) gUartBase + MSR_OFFSET);
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| 
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|   if ((Msr & MSR_CTS) == MSR_CTS) {
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|     *Control |= EFI_SERIAL_CLEAR_TO_SEND;
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|   }
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| 
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|   if ((Msr & MSR_DSR) == MSR_DSR) {
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|     *Control |= EFI_SERIAL_DATA_SET_READY;
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|   }
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| 
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|   if ((Msr & MSR_RI) == MSR_RI) {
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|     *Control |= EFI_SERIAL_RING_INDICATE;
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|   }
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| 
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|   if ((Msr & MSR_DCD) == MSR_DCD) {
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|     *Control |= EFI_SERIAL_CARRIER_DETECT;
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|   }
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| 
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|   //
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|   // Read the Modem Control Register.
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|   //
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|   Mcr = IoRead8 ((UINT16) gUartBase + MCR_OFFSET);
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| 
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|   if ((Mcr & MCR_DTRC) == MCR_DTRC) {
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|     *Control |= EFI_SERIAL_DATA_TERMINAL_READY;
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|   }
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| 
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|   if ((Mcr & MCR_RTS) == MCR_RTS) {
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|     *Control |= EFI_SERIAL_REQUEST_TO_SEND;
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|   }
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| 
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|   //
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|   // Read the Line Status Register.
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|   //
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|   Lsr = IoRead8 ((UINT16) gUartBase + LSR_OFFSET);
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| 
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|   if ((Lsr & LSR_TXRDY) == LSR_TXRDY) {
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|     *Control |= EFI_SERIAL_OUTPUT_BUFFER_EMPTY;
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|   }
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| 
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|   if ((Lsr & LSR_RXDA) == 0) {
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|     *Control |= EFI_SERIAL_INPUT_BUFFER_EMPTY;
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|   }
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| 
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|   return RETURN_SUCCESS;
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| }
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| 
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| /**
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|   Sets the baud rate, receive FIFO depth, transmit/receice time out, parity,
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|   data bits, and stop bits on a serial device.
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| 
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|   @param BaudRate           The requested baud rate. A BaudRate value of 0 will use the
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|                             device's default interface speed.
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|                             On output, the value actually set.
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|   @param ReveiveFifoDepth   The requested depth of the FIFO on the receive side of the
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|                             serial interface. A ReceiveFifoDepth value of 0 will use
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|                             the device's default FIFO depth.
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|                             On output, the value actually set.
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|   @param Timeout            The requested time out for a single character in microseconds.
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|                             This timeout applies to both the transmit and receive side of the
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|                             interface. A Timeout value of 0 will use the device's default time
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|                             out value.
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|                             On output, the value actually set.
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|   @param Parity             The type of parity to use on this serial device. A Parity value of
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|                             DefaultParity will use the device's default parity value.
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|                             On output, the value actually set.
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|   @param DataBits           The number of data bits to use on the serial device. A DataBits
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|                             vaule of 0 will use the device's default data bit setting.
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|                             On output, the value actually set.
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|   @param StopBits           The number of stop bits to use on this serial device. A StopBits
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|                             value of DefaultStopBits will use the device's default number of
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|                             stop bits.
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|                             On output, the value actually set.
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| 
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|   @retval RETURN_SUCCESS            The new attributes were set on the serial device.
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|   @retval RETURN_UNSUPPORTED        The serial device does not support this operation.
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|   @retval RETURN_INVALID_PARAMETER  One or more of the attributes has an unsupported value.
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|   @retval RETURN_DEVICE_ERROR       The serial device is not functioning correctly.
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| 
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| **/
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| RETURN_STATUS
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| EFIAPI
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| SerialPortSetAttributes (
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|   IN OUT UINT64             *BaudRate,
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|   IN OUT UINT32             *ReceiveFifoDepth,
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|   IN OUT UINT32             *Timeout,
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|   IN OUT EFI_PARITY_TYPE    *Parity,
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|   IN OUT UINT8              *DataBits,
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|   IN OUT EFI_STOP_BITS_TYPE *StopBits
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|   )
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| {
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|   UINTN Divisor;
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|   UINT8 OutputData;
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|   UINT8 LcrData;
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|   UINT8 LcrParity;
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|   UINT8 LcrStop;
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| 
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|   //
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|   // Check for default settings and fill in actual values.
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|   //
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|   if (*BaudRate == 0) {
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|     *BaudRate = gBps;
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|   }
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| 
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|   if (*DataBits == 0) {
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|     *DataBits = gData;
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|   }
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| 
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|   if (*Parity == DefaultParity) {
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|     *Parity = NoParity;
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|   }
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| 
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|   if (*StopBits == DefaultStopBits) {
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|     *StopBits = OneStopBit;
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|   }
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| 
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|   if ((*DataBits < 5) || (*DataBits > 8)) {
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|     return RETURN_INVALID_PARAMETER;
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|   }
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| 
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|   //
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|   // Map 5..8 to 0..3
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|   //
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|   LcrData = (UINT8) (*DataBits - (UINT8) 5);
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| 
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|   switch (*Parity) {
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|     case NoParity:
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|       LcrParity = 0;
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|       break;
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| 
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|     case EvenParity:
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|       LcrParity = 3;
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|       break;
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| 
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|     case OddParity:
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|       LcrParity = 1;
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|       break;
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| 
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|     case SpaceParity:
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|       LcrParity = 7;
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|       break;
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| 
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|     case MarkParity:
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|       LcrParity = 5;
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|       break;
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| 
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|     default:
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|       return RETURN_INVALID_PARAMETER;
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|   }
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| 
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|   switch (*StopBits) {
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|     case OneStopBit:
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|       LcrStop = 0;
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|       break;
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| 
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|     case OneFiveStopBits:
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|     case TwoStopBits:
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|       LcrStop = 1;
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|       break;
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| 
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|     default:
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|       return RETURN_INVALID_PARAMETER;
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|   }
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| 
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|   //
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|   // Calculate divisor for baud generator
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|   //
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|   Divisor = 115200 / (UINTN) *BaudRate;
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| 
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|   //
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|   // Set communications format
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|   //
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|   OutputData = (UINT8) ((DLAB << 7) | (gBreakSet << 6) | (LcrParity << 3) | (LcrStop << 2) | LcrData);
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|   IoWrite8 (gUartBase + LCR_OFFSET, OutputData);
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| 
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|   //
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|   // Configure baud rate
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|   //
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|   IoWrite8 (gUartBase + BAUD_HIGH_OFFSET, (UINT8) (Divisor >> 8));
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|   IoWrite8 (gUartBase + BAUD_LOW_OFFSET, (UINT8) (Divisor & 0xff));
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| 
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|   //
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|   // Switch back to bank 0
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|   //
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|   OutputData = (UINT8) ((gBreakSet << 6) | (LcrParity << 3) | (LcrStop << 2) | LcrData);
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|   IoWrite8 (gUartBase + LCR_OFFSET, OutputData);
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| 
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|   return RETURN_SUCCESS;
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| }
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| 
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