uart_405.c

完整的Bell实验室的嵌入式文件系统TFS

#include "config.h"
#include "devices.h"
#include "stddefs.h"
#include "ether.h"

#define UARTA   ((struct uart405 *)0xef600300)
#define UARTB   ((struct uart405 *)0xef600400)

#define DLAB    0x80
#define THRE    0x20    /* Transmit Holding Register Empty */
#define DRDY    0x01    /* Data ready */

struct uart405 {
    union {
        vuchar  data;       /* DATA_REG */
        vuchar  dllsb;      /* DL_LSB (when DLAB is set in linectl reg) */
    } b0;
    union {
        vuchar  inte;       /* INT_ENABLE */
        vuchar  dlmsb;      /* DL_MSB when DLAB is set in linectl reg) */
    } b1;
    vuchar  fifoctl;        /* FIFO_CONTROL */
    vuchar  linectl;        /* LINE_CONTROL */
    vuchar  modemctl;       /* MODEM_CONTROL */
    vuchar  linestat;       /* LINE_STATUS */
    vuchar  modemstat;      /* MODEM_STATUS */
    vuchar  scratch;        /* SCRATCH */
};

void
Init405DUART(struct uart405 *uart, uchar dllsb)
{
    uchar   tmp;

    uart->linectl = DLAB;           /* set DLAB bit */
    uart->b0.dllsb = dllsb;         /* Set baud */
    uart->b1.dlmsb = 0x00;
    uart->linectl = 0x03;           /* 8-bits, no parity */
    uart->fifoctl = 0x00;           /* fifo disabled */
    uart->modemctl = 0x03;          /* DTR/RTS */
    tmp = uart->linestat;           /* clear line stat */
    tmp = uart->b0.data;            /* read receive buffer */
    uart->scratch = 0x00;           /* set scratch pad */
    uart->b1.inte = 0x00;           /* no ints used */
}

uchar
getDlLsb(int baud)
{
    uchar   dllsb;

    switch(baud) {
        case 115200:
            dllsb = BRD_115200;
            break;
        case 57600:
            dllsb = BRD_57600;
            break;
        case 38400:
            dllsb = BRD_38400;
            break;
        case 19200:
            dllsb = BRD_19200;
            break;
        default:
        case 9600:
            dllsb = BRD_9600;
            break;
    }
    return(dllsb);
}

void
setBaud(struct uart405 *uart, int baud)
{
    uchar   tmp;

    tmp = uart->linectl;                /* Save linectl reg */
    uart->linectl = DLAB;               /* set DLAB bit */
    uart->b0.dllsb = getDlLsb(baud);    /* Set baud */
    uart->b1.dlmsb = 0x00;
    uart->linectl = tmp;                /* Restore linectl reg */
}

void
Init405UART(int baud)
{
    Init405DUART(UARTA,getDlLsb(baud));
    Init405DUART(UARTB,getDlLsb(baud));
}

int
gotachar405_A()
{
    if (UARTA->linestat & DRDY)
        return(1);
    return(0);
}

int
getchar405_A()
{
    while(!gotachar405_A());
    return((int)(UARTA->b0.data));
}

int
rputchar405_A(char c)
{
    UARTA->b0.data = c;
    while(!(UARTA->linestat & THRE));
    return(0);
}

int
gotachar405_B()
{
    if (UARTB->linestat & DRDY)
        return(1);
    return(0);
}

int
getchar405_B()
{
    while(!gotachar405_B());
    return((int)(UARTB->b0.data));
}

int
rputchar405_B(char c)
{
    UARTB->b0.data = c;
    while(!(UARTB->linestat & THRE));
    return(0);
}

int
tty0init(ulong baud)
{
    extern int InitUART(int);

    InitUART(baud);
    Init405DUART(UARTA,getDlLsb(baud));
    return(0);
}

int
tty0read(char *buf,int cnt)
{
    int i;

    for(i=0;i<cnt;i++) {
        while(!gotachar405_A()) {
#if INCLUDE_ETHERNET
            pollethernet();
#endif
        }
        buf[i] = getchar405_A();
    }
    return(cnt);
}

int
tty0write(char *buf,int cnt)
{
    int i;

    for(i=0;i<cnt;i++)
        rputchar405_A(buf[i]);
    return(cnt);
}

int
tty0ctrl(int func,ulong arg0,ulong arg1)
{
    switch(func) {
        case GOTACHAR:
            return(gotachar405_A());
            break;
        case SETBAUD:
            setBaud(UARTA,(int)arg0);
            break;
        case INIT:
            Init405DUART(UARTA,getDlLsb(arg0));
            break;
        default:
            return(-1);
    }
    return(0);
}

int
tty1init(ulong baud)
{
    Init405DUART(UARTB,getDlLsb(baud));
    return(0);
}

int
tty1read(char *buf,int cnt)
{
    int i;

    for(i=0;i<cnt;i++) {
        while(!gotachar405_B()) {
#if INCLUDE_ETHERNET
            pollethernet();
#endif
        }
        buf[i] = getchar405_B();
    }
    return(cnt);
}

int
tty1write(char *buf,int cnt)
{
    int i;

    for(i=0;i<cnt;i++)
        rputchar405_B(buf[i]);
    return(cnt);
}

int
tty1ctrl(int func,ulong arg0,ulong arg1)
{
    switch(func) {
        case GOTACHAR:
            return(gotachar405_B());
            break;
        case SETBAUD:
            setBaud(UARTB,(int)arg0);
            break;
        case INIT:
            Init405DUART(UARTB,getDlLsb(arg0));
            break;
        default:
            return(-1);
    }
    return(0);
}