u-boot/cpu/coldfire/serial.c

/*
 * (C) Copyright 2000-2003
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <commproc.h>
#include <command.h>

#ifdef CONFIG_M5272
#include <asm/m5272.h>
#endif
#ifdef CONFIG_M5282
#include <asm/m5282.h>
#endif
#include <asm/mcfuart.h>

#define DoubleClock(a) ((double)(MCF_CLK) / 32.0 / (double)(a))

void rs_serial_setbaudrate (int port, int baudrate)
{
#ifdef CONFIG_M5272
	volatile unsigned char *uartp;
	double clock, fraction;

	if (port == 0)
		uartp = (volatile unsigned char *) (MCF_MBAR + MCFUART_BASE1);
	else
		uartp = (volatile unsigned char *) (MCF_MBAR + MCFUART_BASE2);

	clock = DoubleClock (baudrate);	/* Set baud above */

	fraction = ((clock - (int) clock) * 16.0) + 0.5;

	uartp[MCFUART_UBG1] = (((int) clock >> 8) & 0xff);	/* set msb baud */
	uartp[MCFUART_UBG2] = ((int) clock & 0xff);	/* set lsb baud */
	uartp[MCFUART_UFPD] = ((int) fraction & 0xf);	/* set baud fraction adjust */
#endif
}

void rs_serial_init (int port, int baudrate)
{
	volatile unsigned char *uartp;
	double clock, fraction;

	/*
	 *      Reset UART, get it into known state...
	 */
	if (port == 0)
		uartp = (volatile unsigned char *) (MCF_MBAR + MCFUART_BASE1);
	else
		uartp = (volatile unsigned char *) (MCF_MBAR + MCFUART_BASE2);

	uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETRX;	/* reset RX */
	uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETTX;	/* reset TX */
	uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETMRPTR;	/* reset MR pointer */
	uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETERR;	/* reset Error pointer */

	/*
	 * Set port for CONSOLE_BAUD_RATE, 8 data bits, 1 stop bit, no parity.
	 */
	uartp[MCFUART_UMR] = MCFUART_MR1_PARITYNONE | MCFUART_MR1_CS8;
	uartp[MCFUART_UMR] = MCFUART_MR2_STOP1;

	rs_serial_setbaudrate (port, baudrate);

	uartp[MCFUART_UCSR] =
		MCFUART_UCSR_RXCLKTIMER | MCFUART_UCSR_TXCLKTIMER;
	uartp[MCFUART_UCR] = MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE;

	return;
}


/****************************************************************************/

/*
 *	Output a single character, using UART polled mode.
 *	This is used for console output.
 */

void rs_put_char (char ch)
{
	volatile unsigned char *uartp;
	int i;

	uartp = (volatile unsigned char *) (MCF_MBAR + MCFUART_BASE1);

	for (i = 0; (i < 0x10000); i++) {
		if (uartp[MCFUART_USR] & MCFUART_USR_TXREADY)
			break;
	}
	uartp[MCFUART_UTB] = ch;
	return;
}

int rs_is_char (void)
{
	volatile unsigned char *uartp;

	uartp = (volatile unsigned char *) (MCF_MBAR + MCFUART_BASE1);
	return ((uartp[MCFUART_USR] & MCFUART_USR_RXREADY) ? 1 : 0);
}

int rs_get_char (void)
{
	volatile unsigned char *uartp;

	uartp = (volatile unsigned char *) (MCF_MBAR + MCFUART_BASE1);
	return (uartp[MCFUART_URB]);
}

void serial_setbrg (void)
{
	DECLARE_GLOBAL_DATA_PTR;
	rs_serial_setbaudrate (0, gd->bd->bi_baudrate);
}

int serial_init (void)
{
	DECLARE_GLOBAL_DATA_PTR;
	rs_serial_init (0, gd->bd->bi_baudrate);
	return 0;
}


void serial_putc (const char c)
{
	if (c == '\n')
		serial_putc ('\r');
	rs_put_char (c);
}

void serial_puts (const char *s)
{
	while (*s) {
		serial_putc (*s++);
	}
}

int serial_getc (void)
{
	while (!rs_is_char ());
	return rs_get_char ();
}

int serial_tstc ()
{
	return rs_is_char ();
}