boot/armllb/hw/versatile/hwuart.c

   1 /*
   2  * PROJECT:         ReactOS Boot Loader
   3  * LICENSE:         BSD - See COPYING.ARM in the top level directory
   4  * FILE:            boot/armllb/hw/versatile/hwuart.c
   5  * PURPOSE:         LLB UART Initialization Routines for Versatile
   6  * PROGRAMMERS:     ReactOS Portable Systems Group
   7  */
   8
   9 #include "precomp.h"
  10
  11 //
  12 // UART Registers
  13 //
  14 #define UART_PL01x_DR            (LlbHwVersaUartBase + 0x00)
  15 #define UART_PL01x_RSR           (LlbHwVersaUartBase + 0x04)
  16 #define UART_PL01x_ECR           (LlbHwVersaUartBase + 0x04)
  17 #define UART_PL01x_FR            (LlbHwVersaUartBase + 0x18)
  18 #define UART_PL011_IBRD          (LlbHwVersaUartBase + 0x24)
  19 #define UART_PL011_FBRD          (LlbHwVersaUartBase + 0x28)
  20 #define UART_PL011_LCRH          (LlbHwVersaUartBase + 0x2C)
  21 #define UART_PL011_CR            (LlbHwVersaUartBase + 0x30)
  22 #define UART_PL011_IMSC          (LlbHwVersaUartBase + 0x38)
  23
  24 //
  25 // LCR Values
  26 //
  27 #define UART_PL011_LCRH_WLEN_8   0x60
  28 #define UART_PL011_LCRH_FEN      0x10
  29
  30 //
  31 // FCR Values
  32 //
  33 #define UART_PL011_CR_UARTEN     0x01
  34 #define UART_PL011_CR_TXE        0x100
  35 #define UART_PL011_CR_RXE        0x200
  36
  37 //
  38 // LSR Values
  39 //
  40 #define UART_PL01x_FR_RXFE       0x10
  41 #define UART_PL01x_FR_TXFF       0x20
  42
  43 static const ULONG LlbHwVersaUartBase = 0x101F1000;
  44
  45 /* FUNCTIONS ******************************************************************/
  46
  47 VOID
  48 NTAPI
  49 LlbHwVersaUartInitialize(VOID)
  50 {
  51     ULONG Divider, Remainder, Fraction, ClockRate, Baudrate;
  52
  53     /* Query peripheral rate, hardcore baudrate */
  54     ClockRate = LlbHwGetPClk();
  55     Baudrate = 115200;
  56
  57     /* Calculate baudrate clock divider and remainder */
  58     Divider = ClockRate / (16 * Baudrate);
  59     Remainder = ClockRate % (16 * Baudrate);
  60
  61     /* Calculate the fractional part */
  62     Fraction = (8 * Remainder / Baudrate) >> 1;
  63     Fraction += (8 * Remainder / Baudrate) & 1;
  64
  65     /* Disable interrupts */
  66     WRITE_REGISTER_ULONG(UART_PL011_CR, 0);
  67
  68     /* Set the baud rate to 115200 bps */
  69     WRITE_REGISTER_ULONG(UART_PL011_IBRD, Divider);
  70     WRITE_REGISTER_ULONG(UART_PL011_FBRD, Fraction);
  71
  72     /* Set 8 bits for data, 1 stop bit, no parity, FIFO enabled */
  73     WRITE_REGISTER_ULONG(UART_PL011_LCRH,
  74                          UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN);
  75
  76     /* Clear and enable FIFO */
  77     WRITE_REGISTER_ULONG(UART_PL011_CR,
  78                          UART_PL011_CR_UARTEN |
  79                          UART_PL011_CR_TXE |
  80                          UART_PL011_CR_RXE);
  81 }
  82
  83 VOID
  84 NTAPI
  85 LlbHwUartSendChar(IN CHAR Char)
  86 {
  87     /* Send the character */
  88     WRITE_REGISTER_ULONG(UART_PL01x_DR, Char);
  89 }
  90
  91 BOOLEAN
  92 NTAPI
  93 LlbHwUartTxReady(VOID)
  94 {
  95     /* TX output buffer is ready? */
  96     return ((READ_REGISTER_ULONG(UART_PL01x_FR) & UART_PL01x_FR_TXFF) == 0);
  97 }
  98
  99 ULONG
 100 NTAPI
 101 LlbHwGetUartBase(IN ULONG Port)
 102 {
 103     if (Port == 0)
 104     {
 105         return 0x101F1000;
 106     }
 107     else if (Port == 1)
 108     {
 109         return 0x101F2000;
 110     }
 111
 112     return 0;
 113 }
 114
 115 /* EOF */