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;
}