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/*
* COM1 NS16550 support
*/
#include "ns16550.h"
typedef struct NS16550 *NS16550_t;
const NS16550_t COM_PORTS[] = { (NS16550_t) COM1,
(NS16550_t) COM2,
(NS16550_t) COM3,
(NS16550_t) COM4 };
volatile struct NS16550 *
NS16550_init(int chan)
{
volatile struct NS16550 *com_port;
volatile unsigned char xx;
com_port = (struct NS16550 *) COM_PORTS[chan];
/* See if port is present */
com_port->lcr = 0x00;
com_port->ier = 0xFF;
#if 0
if (com_port->ier != 0x0F) return ((struct NS16550 *)0);
#endif
com_port->ier = 0x00;
com_port->lcr = 0x80; /* Access baud rate */
com_port->dll = 0xc; /* 9600 baud */
com_port->dlm = 0xc >> 8;
com_port->lcr = 0x03; /* 8 data, 1 stop, no parity */
com_port->mcr = 0x03; /* RTS/DTR */
com_port->fcr = 0x07; /* Clear & enable FIFOs */
return (com_port);
}
NS16550_putc(volatile struct NS16550 *com_port, unsigned char c)
{
volatile int i;
while ((com_port->lsr & LSR_THRE) == 0) ;
com_port->thr = c;
}
unsigned char
NS16550_getc(volatile struct NS16550 *com_port)
{
while ((com_port->lsr & LSR_DR) == 0) ;
return (com_port->rbr);
}
NS16550_tstc(volatile struct NS16550 *com_port)
{
return ((com_port->lsr & LSR_DR) != 0);
}
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