source: XOpenSparcT1/trunk/sw/uart.c @ 32

#include "uart.h"

const int UART_BASE_ADR[1] = {0};
const int UART_BAUDS[1] = {0};
const int IN_CLK =50000000;

#define REG8(add) *((volatile unsigned char *)(add))

#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)

#define WAIT_FOR_XMITR(core)                    \
do { \
lsr = REG8(UART_BASE_ADR[core] + UART_LSR); \
} while ((lsr & BOTH_EMPTY) != BOTH_EMPTY)

#define WAIT_FOR_THRE(core)                     \
do { \
lsr = REG8(UART_BASE_ADR[core] + UART_LSR); \
} while ((lsr & UART_LSR_THRE) != UART_LSR_THRE)

#define CHECK_FOR_CHAR(core) (REG8(UART_BASE_ADR[core] + UART_LSR) & UART_LSR_DR)

#define WAIT_FOR_CHAR(core)                     \
do { \
lsr = REG8(UART_BASE_ADR[core] + 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 main() __attribute__((noreturn));
void main() 
{
        asm("mov 0x00, %sp\n");
        asm("mov 0x00, %fp\n");
        uart_init(0);
        for(;;) { 
                uart_puts(0,"XOpenSparc is alive \n"); 
        } 
        //return;
}

void uart_init(char core)
{
        long allone=0xffffffffffffffff;
        int divisor;
        float float_divisor;
        
        /* Reset receiver and transmiter */
        REG8( UART_FCR ) = UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT | UART_FCR_TRIGGER_14;
        
        /* Disable all interrupts */
        REG8(UART_BASE_ADR[core] + UART_IER) = 0x00;
        
        /* Set 8 bit char, 1 stop bit, no parity */
        REG8(UART_BASE_ADR[core] + UART_LCR) = UART_LCR_WLEN8 & ~(UART_LCR_STOP | UART_LCR_PARITY);
        
        /* Set baud rate */
        float_divisor = (float) IN_CLK/(16 * UART_BAUDS[core]);
        float_divisor += 0.50f; // Ensure round up
        divisor = (int) float_divisor;
        
        REG8(UART_BASE_ADR[core] + UART_LCR) |= UART_LCR_DLAB;
        REG8(UART_BASE_ADR[core] + UART_DLL) = divisor & 0x000000ff;
        REG8(UART_BASE_ADR[core] + UART_DLM) = (divisor >> 8) & 0x000000ff;
        REG8(UART_BASE_ADR[core] + UART_LCR) &= ~(UART_LCR_DLAB);
        
        return;
}

void uart_putc(char core, char c)
{
        unsigned char lsr;
        
        WAIT_FOR_THRE(core);
        REG8(UART_BASE_ADR[core] + UART_TX) = c;
        if(c == '\n') {
                WAIT_FOR_THRE(core);
                REG8(UART_BASE_ADR[core] + UART_TX) = '\r';
        }
        WAIT_FOR_XMITR(core);
}

void uart_puts (char core, char *s) { 
        // loop until *s != NULL 
        while (*s) { 
                uart_putc(core,*s); 
                s++; 
        } 
}



// Only used when we know THRE is empty, typically in interrupt
/*void uart_putc_noblock(char core, char c)
{
        REG8(UART_BASE_ADR[core] + UART_TX) = c;
}


char uart_getc(char core)
{
        unsigned char lsr;
        char c;
        
        WAIT_FOR_CHAR(core);
        c = REG8(UART_BASE_ADR[core] + UART_RX);
        return c;
}

int uart_check_for_char(char core)
{
        return CHECK_FOR_CHAR(core);
}

void uart_rxint_enable(char core)
{
        REG8(UART_BASE_ADR[core] + UART_IER) |= UART_IER_RDI;
}

void uart_rxint_disable(char core)
{
        REG8(UART_BASE_ADR[core] + UART_IER) &= ~(UART_IER_RDI);
}

void uart_txint_enable(char core)
{
        REG8(UART_BASE_ADR[core] + UART_IER) |= UART_IER_THRI;
}

void uart_txint_disable(char core)
{
        REG8(UART_BASE_ADR[core] + UART_IER) &= ~(UART_IER_THRI);
}

char uart_get_iir(char core)
{
        return REG8(UART_BASE_ADR[core] + UART_IIR);
}


char uart_get_lsr(char core)
{
        return REG8(UART_BASE_ADR[core] + UART_LSR);
}


char uart_get_msr(char core)
{
        return REG8(UART_BASE_ADR[core] + UART_MSR);
}
*/