/***************************************************************************
 *   sam7fc - Debug Unit RS232 Port                                        *
 *                                                                         *
 *   Copyright (C) 01/2008 by Olaf Rempel                                  *
 *   razzor@kopf-tisch.de                                                  *
 *                                                                         *
 *   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; version 2 of the License                *
 *                                                                         *
 *   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 <stdint.h>
#include <string.h>
#include "AT91SAM7S256.h"
#include "board.h"
#include "at91_dbgu.h"
#include "at91_sysc.h"
#include "fifo.h"

#define DBGU_BAUDRATE	115200
#define DBGU_FIFO_SIZE	1024
#define DBGU_TX_CHUNKS	16

static struct fifo *txfifo;

static void dbgu_isr(uint32_t status)
{
	/* only enabled interrupts */
	status &= *AT91C_DBGU_IMR;
	if (status & AT91C_US_TXBUFE)
		if (fifo_txpdc(txfifo, AT91C_BASE_PDC_DBGU, DBGU_TX_CHUNKS) == 0)
			*AT91C_DBGU_IDR = AT91C_US_TXBUFE;
}

void at91_dbgu_init(void)
{
	/* switch pins to UART */
	*AT91C_PIOA_PDR = AT91C_PA9_DRXD | AT91C_PA10_DTXD;

	/* enable Debug Port with 115200 Baud (+0.16%) */
	AT91S_DBGU *dbgu = AT91C_BASE_DBGU;
	dbgu->DBGU_BRGR = BAUD_TO_DIV(DBGU_BAUDRATE);
	dbgu->DBGU_MR = AT91C_US_PAR_NONE | AT91C_US_CHMODE_NORMAL;
	dbgu->DBGU_CR = AT91C_US_RXEN | AT91C_US_TXEN | AT91C_US_RSTSTA;

	txfifo = fifo_alloc(DBGU_FIFO_SIZE);

	/* enable TX PDC */
	dbgu->DBGU_PTCR = AT91C_PDC_TXTEN;

	sysc_register_isr(AT91_SYSIRQ_DBGU, dbgu_isr);
}

void at91_dbgu_putc(char c)
{
	fifo_putbyte(txfifo, c);
	*AT91C_DBGU_IER = AT91C_US_TXBUFE;
}

void at91_dbgu_puts(const char *p)
{
	fifo_put(txfifo, (char *)p, strlen(p));
	*AT91C_DBGU_IER = AT91C_US_TXBUFE;
}

int at91_dbgu_write(void *base, const char *buf, size_t len)
{
	int retval = fifo_put(txfifo, (char *)buf, len);
	*AT91C_DBGU_IER = AT91C_US_TXBUFE;
	return retval;
}