buart.c

Boot code for ADM5120 with serial console for Edimax router.

/*****************************************************************************
;
;    Project : ADM5120
;    Creator : David Weng
;    File    : buart.c
;    Abstract: UART functions for plugins
;    Description: Taken almost verbaim from "admboot/src/uartdrv.c"
;
;*****************************************************************************/

#include <ctype.h>
#include <mips4kc.h>
#include <adm5120.h>
#include <buart.h>
#include <uartdrv.h>
#include <bconfig.h>

#define TRUE		1
#define FALSE		0

#define UART_REG_READ(_uart, _reg)			\
	*((volatile unsigned long *)(((_uart)->io_base) + (_reg)))


#define UART_REG_WRITE(_uart, _reg, _val)	\
	*((volatile unsigned long *)(((_uart)->io_base) + (_reg))) = (_val)

static UART_OBJ uart = { 0, PA2VA(ADM5120_UART0_BASE), 0, 0 };
static UINT32 timeticks = 0;


UINT32 UpTime(void)
{
	unsigned long status;

	status = ADM5120_SW_REG(Timer_int_REG);

	if (status & SW_TIMER_INT) {
		/* Acknowledge the timer interrupt */
		ADM5120_SW_REG(Timer_int_REG) = status;
		timeticks++;
	}

	return timeticks;
}


static int buart_read()
{
	UINT32 uartfr;
	UINT32 uartsr, data;

	uartfr = UART_REG_READ(&uart, UART_FR_REG);

	if ( ! (uartfr & UART_RX_FIFO_EMPTY)) {
        data = UART_REG_READ(&uart, UART_DR_REG);
		uartsr = UART_REG_READ(&uart, UART_RSR_REG);

		if (uartsr & UART_RX_ERROR) {
			UART_REG_WRITE(&uart, UART_ECR_REG, uartsr);
			return -1;
		}

		if (uartsr & UART_OVERRUN_ERR) {
			UART_REG_WRITE(&uart, UART_ECR_REG, uartsr);
		}

		return (data & 0xff);
	}

    return -1;
}


static int buart_write(char c)
{
	UINT32 uartfr;

	uartfr = UART_REG_READ(&uart, UART_FR_REG);

	if ( ! (uartfr & UART_TX_FIFO_EMPTY))
		return -1;

	UART_REG_WRITE(&uart, UART_DR_REG, (UINT32) c);

    return 0;
}


void buart_print(char *str)
{
	for ( ; *str; str++) {
		while (buart_write(*str) == -1)
			;
	}

	return;
}


void buart_put(char c)
{
	while (buart_write (c) == -1)
		;

	return;
}


int buart_get (int timeout)
{
    register int c;
    register unsigned long ticks;

    // If no wait specified then read the channel immediately
    if (timeout == 0)
        return buart_read();

    // time-out set, block read
    ticks = UpTime();

	while ((int)(UpTime() - ticks) < (timeout * 100)) {
		if ((c = buart_read()) != -1)
			return c;
	}

	return -1;
}


char buart_getchar(void)
{
	register int c;

	while ((c = buart_get(0)) == -1)
		;

	return (char) c;
}


void ReadLine(char *buf, int num)
{
	int i, userKey;
	char readBuf[32];
	char *preadBuf;
	int cpNum;
	int esc_cnt = 0;

	for (i = 0; i < 32; i++)
		readBuf[i] = '\0';

	for (i = 0; i < 256; i++) {
GETKEY:		/* UGH */
		userKey = buart_getchar();
		
		if (esc_cnt) {
			esc_cnt--;
			goto GETKEY;	/* UGH */
		}

		if (userKey == 0x0d || userKey == 0x0a) {
			readBuf[i] = 0;
			buart_print("\r\n");
			break;
		} else if (userKey == 0x1b) {
			esc_cnt = 2;
			goto GETKEY;	/* UGH */
		} else if (userKey == 0x08) {
			if (--i < 0) {
				i = 0;
				goto GETKEY;	/* UGH */
			}

			readBuf[i] = 0;
			--i;
		} else {
			buart_put(userKey);
			readBuf[i] = (char) userKey;
		}
	}

	if (i < 0) {
		*buf = 0;
		return;
	} else if (++i <= num)
		cpNum = i;
	else {
		cpNum = num;
		
		// truncate the input string.
		buf[num-1] = 0;
	}

	preadBuf = readBuf;

	while (cpNum > 0) {
		cpNum--;
		if ((*buf++ = *preadBuf++) == 0)
			break;
	}
}