Subversion Repositories openrisc_2011-10-31

#include "support.h"

#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)

#define UART_TX_BUFF_LEN 32

#define UART_TX_BUFF_MASK (UART_TX_BUFF_LEN -1)

char tx_buff[UART_TX_BUFF_LEN];

volatile int tx_level, rx_level;

void uart_init(void)

{

        int divisor;

        float float_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_4;

        /* 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 */

        float_divisor = (float) IN_CLK/(16 * UART_BAUD_RATE);

        float_divisor += 0.50f; // Ensure round up

        divisor = (int) float_divisor;

        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 uart_testc(void)

{

        if((REG8(UART_BASE + UART_LSR) & UART_LSR_DR) == UART_LSR_DR)

                return REG8(UART_BASE + UART_RX);

        else

                return 0;

}