ArmEbPkg/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/DebugLib.h>
  19 #include <Library/SerialPortLib.h>
  20 #include <Library/PcdLib.h>
  21 #include <Library/IoLib.h>
  22
  23 #include <ArmEb/ArmEb.h>
  24
  25 /*
  26
  27   Programmed hardware of Serial port.
  28
  29   @return    Always return EFI_UNSUPPORTED.
  30
  31 **/
  32 RETURN_STATUS
  33 EFIAPI
  34 SerialPortInitialize (
  35   VOID
  36   )
  37 {
  38   UINT32  Base = PcdGet32 (PcdConsoleUart);
  39
  40   // initialize baud rate generator to 115200 based on EB clock REFCLK24MHZ
  41   MmioWrite32 (Base + UARTIBRD, UART_115200_IDIV);
  42   MmioWrite32 (Base + UARTFBRD, UART_115200_FDIV);
  43
  44   // no parity, 1 stop, no fifo, 8 data bits
  45   MmioWrite32 (Base + UARTLCR_H, 0x60);
  46
  47   // clear any pending errors
  48   MmioWrite32 (Base + UARTECR, 0);
  49
  50   // enable tx, rx, and uart overall
  51   MmioWrite32 (Base + UARTCR, 0x301);
  52
  53   return RETURN_SUCCESS;
  54 }
  55
  56 /**
  57   Write data to serial device.
  58
  59   @param  Buffer           Point of data buffer which need to be writed.
  60   @param  NumberOfBytes    Number of output bytes which are cached in Buffer.
  61
  62   @retval 0                Write data failed.
  63   @retval !0               Actual number of bytes writed to serial device.
  64
  65 **/
  66 UINTN
  67 EFIAPI
  68 SerialPortWrite (
  69   IN UINT8     *Buffer,
  70   IN UINTN     NumberOfBytes
  71 )
  72 {
  73   UINT32 FR = PcdGet32(PcdConsoleUart) + UARTFR;
  74   UINT32 DR = PcdGet32(PcdConsoleUart) + UARTDR;
  75   UINTN  Count;
  76
  77   for (Count = 0; Count < NumberOfBytes; Count++, Buffer++) {
  78     while ((MmioRead32 (FR) & UART_TX_EMPTY_FLAG_MASK) != 0);
  79     MmioWrite8 (DR, *Buffer);
  80   }
  81
  82   return NumberOfBytes;
  83 }
  84
  85
  86 /**
  87   Read data from serial device and save the datas in buffer.
  88
  89   @param  Buffer           Point of data buffer which need to be writed.
  90   @param  NumberOfBytes    Number of output bytes which are cached in Buffer.
  91
  92   @retval 0                Read data failed.
  93   @retval !0               Aactual number of bytes read from serial device.
  94
  95 **/
  96 UINTN
  97 EFIAPI
  98 SerialPortRead (
  99   OUT UINT8     *Buffer,
 100   IN  UINTN     NumberOfBytes
 101 )
 102 {
 103   UINT32  FR = PcdGet32(PcdConsoleUart) + UARTFR;
 104   UINT32  DR = PcdGet32(PcdConsoleUart) + UARTDR;
 105   UINTN   Count;
 106
 107   for (Count = 0; Count < NumberOfBytes; Count++, Buffer++) {
 108     while ((MmioRead32 (FR) & UART_RX_EMPTY_FLAG_MASK) == 0);
 109     *Buffer = MmioRead8 (DR);
 110   }
 111
 112   return NumberOfBytes;
 113 }
 114
 115
 116 /**
 117   Check to see if any data is avaiable to be read from the debug device.
 118
 119   @retval EFI_SUCCESS       At least one byte of data is avaiable to be read
 120   @retval EFI_NOT_READY     No data is avaiable to be read
 121   @retval EFI_DEVICE_ERROR  The serial device is not functioning properly
 122
 123 **/
 124 BOOLEAN
 125 EFIAPI
 126 SerialPortPoll (
 127   VOID
 128   )
 129 {
 130   UINT32 FR = PcdGet32(PcdConsoleUart) + UARTFR;
 131
 132   if ((MmioRead32 (FR) & UART_RX_EMPTY_FLAG_MASK) == 0) {
 133     return TRUE;
 134   } else {
 135     return FALSE;
 136   }
 137 }
 138