Subversion Repositories openrisc

#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;

}