ArmRealViewEbPkg/Library/SerialPortLib/SerialPortLib.c

   1 /** @file
   2   Serial I/O Port library functions with no library constructor/destructor
   3
   4
   5   Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
   6
   7   This program and the accompanying materials
   8   are licensed and made available under the terms and conditions of the BSD License
   9   which accompanies this distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17 #include <Base.h>
  18 #include <Library/SerialPortLib.h>
  19 #include <Library/PcdLib.h>
  20 #include <Library/IoLib.h>
  21
  22 #include <ArmEb/ArmEb.h>
  23
  24 /*
  25
  26   Programmed hardware of Serial port.
  27
  28   @return    Always return EFI_UNSUPPORTED.
  29
  30 **/
  31 RETURN_STATUS
  32 EFIAPI
  33 SerialPortInitialize (
  34   VOID
  35   )
  36 {
  37   UINT32  Base = PcdGet32 (PcdConsoleUartBase);
  38
  39   // initialize baud rate generator to 115200 based on EB clock REFCLK24MHZ
  40   MmioWrite32 (Base + UARTIBRD, UART_115200_IDIV);
  41   MmioWrite32 (Base + UARTFBRD, UART_115200_FDIV);
  42
  43   // no parity, 1 stop, no fifo, 8 data bits
  44   MmioWrite32 (Base + UARTLCR_H, 0x60);
  45
  46   // clear any pending errors
  47   MmioWrite32 (Base + UARTECR, 0);
  48
  49   // enable tx, rx, and uart overall
  50   MmioWrite32 (Base + UARTCR, 0x301);
  51
  52   return RETURN_SUCCESS;
  53 }
  54
  55 /**
  56   Write data to serial device.
  57
  58   @param  Buffer           Point of data buffer which need to be writed.
  59   @param  NumberOfBytes    Number of output bytes which are cached in Buffer.
  60
  61   @retval 0                Write data failed.
  62   @retval !0               Actual number of bytes writed to serial device.
  63
  64 **/
  65 UINTN
  66 EFIAPI
  67 SerialPortWrite (
  68   IN UINT8     *Buffer,
  69   IN UINTN     NumberOfBytes
  70 )
  71 {
  72   UINT32 FR = PcdGet32 (PcdConsoleUartBase) + UARTFR;
  73   UINT32 DR = PcdGet32 (PcdConsoleUartBase) + UARTDR;
  74   UINTN  Count;
  75
  76   for (Count = 0; Count < NumberOfBytes; Count++, Buffer++) {
  77     while ((MmioRead32 (FR) & UART_TX_EMPTY_FLAG_MASK) == 0);
  78     MmioWrite8 (DR, *Buffer);
  79   }
  80
  81   return NumberOfBytes;
  82 }
  83
  84
  85 /**
  86   Read data from serial device and save the datas in buffer.
  87
  88   @param  Buffer           Point of data buffer which need to be writed.
  89   @param  NumberOfBytes    Number of output bytes which are cached in Buffer.
  90
  91   @retval 0                Read data failed.
  92   @retval !0               Aactual number of bytes read from serial device.
  93
  94 **/
  95 UINTN
  96 EFIAPI
  97 SerialPortRead (
  98   OUT UINT8     *Buffer,
  99   IN  UINTN     NumberOfBytes
 100 )
 101 {
 102   UINT32  FR = PcdGet32 (PcdConsoleUartBase) + UARTFR;
 103   UINT32  DR = PcdGet32 (PcdConsoleUartBase) + UARTDR;
 104   UINTN   Count;
 105
 106   for (Count = 0; Count < NumberOfBytes; Count++, Buffer++) {
 107     while ((MmioRead32 (FR) & UART_RX_EMPTY_FLAG_MASK) != 0);
 108     *Buffer = MmioRead8 (DR);
 109   }
 110
 111   return NumberOfBytes;
 112 }
 113
 114
 115 /**
 116   Check to see if any data is avaiable to be read from the debug device.
 117
 118   @retval EFI_SUCCESS       At least one byte of data is avaiable to be read
 119   @retval EFI_NOT_READY     No data is avaiable to be read
 120   @retval EFI_DEVICE_ERROR  The serial device is not functioning properly
 121
 122 **/
 123 BOOLEAN
 124 EFIAPI
 125 SerialPortPoll (
 126   VOID
 127   )
 128 {
 129   UINT32 FR = PcdGet32 (PcdConsoleUartBase) + UARTFR;
 130
 131   if ((MmioRead32 (FR) & UART_RX_EMPTY_FLAG_MASK) == 0) {
 132     return TRUE;
 133   } else {
 134     return FALSE;
 135   }
 136 }
 137