Subversion Repositories or1k

#include "board.h"

#include "uart.h"

#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)

#define WAIT_FOR_XMITR \

        do { \

                lsr = REG8(UART_BASE + UART_LSR); \

        } while ((lsr & BOTH_EMPTY) != BOTH_EMPTY)

#define WAIT_FOR_THRE \

        do { \

                lsr = REG8(UART_BASE + UART_LSR); \

        } while ((lsr & UART_LSR_THRE) != UART_LSR_THRE)

#define CHECK_FOR_CHAR (REG8(UART_BASE + UART_LSR) & UART_LSR_DR)

#define WAIT_FOR_CHAR \

         do { \

                lsr = REG8(UART_BASE + UART_LSR); \

         } while ((lsr & UART_LSR_DR) != UART_LSR_DR)

void uart_init(void)

{

  int divisor;

  /* Reset receiver and transmiter */

  REG8(UART_BASE + UART_FCR) = UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT | UART_FCR_TRIGGER_14;

  /* Disable all interrupts */

  REG8(UART_BASE + UART_IER) = 0x00;

  /* Set 8 bit char, 1 stop bit, no parity */

  REG8(UART_BASE + UART_LCR) = UART_LCR_WLEN8 & ~(UART_LCR_STOP | UART_LCR_PARITY);

  /* Set baud rate */

  divisor = IN_CLK/(16 * UART_BAUD_RATE);

  REG8(UART_BASE + UART_LCR) |= UART_LCR_DLAB;

  REG8(UART_BASE + UART_DLL) = divisor & 0x000000ff;

  REG8(UART_BASE + UART_DLM) = (divisor >> 8) & 0x000000ff;

  REG8(UART_BASE + UART_LCR) &= ~(UART_LCR_DLAB);

}

void uart_putc(char c)

{

  unsigned char lsr;

  WAIT_FOR_THRE;

  REG8(UART_BASE + UART_TX) = c;

  if(c == '\n') {

    WAIT_FOR_THRE;

    REG8(UART_BASE + UART_TX) = '\r';

  }

  WAIT_FOR_XMITR;

}

char uart_getc(void)

{

  unsigned char lsr;

  char c;

  WAIT_FOR_CHAR;

  c = REG8(UART_BASE + UART_RX);

  return c;

}

char *str = "Hello world!!!\n";

int main (void)

{

  char *s;

  uart_init ();

  for (s = str; *s; s++)

    uart_putc (*s);

  while (1)

    uart_putc (uart_getc () + 1);

  return 0;

}