parport.c

PXA250上的XBOOT

/* 
 * $Id: parport.c,v 1.1 2002/12/05 22:20:38 telka Exp $
 *
 * Copyright (C) 2001, 2002 ETC s.r.o.
 *
 * 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.
 *
 * Written by Marcel Telka <[e-mail]>, 2001, 2002.
 *
 */

#include <_windows.h>
#include <nkintr.h>

#include "board.h"

#include <sa11x0/gpio.h>

#include "parport.h"

/* parallel port communication protocol */
int PP_Protocol = PP_PROTOCOL_MSCEPB;

/* TRUE if error in communication occured */
BOOL NoPPFS = FALSE;

/* 
 * This file implements MS-specific communication via parallel port - needed for CEPB
 * This is not true EPP communication - require brutal hardware hack:
 * must be ACK wired with BUSY (WT)
 * For more info see `Data Transfer Examples' in WinCE 3.0 documentation
 *
 * if you want communicate using standard EPP, set global variable PP_Protocol
 * to PP_PROTOCOL_EPP
 */

int
OEMParallelPortGetByte( void )
{
#if (WID == EI370)
	DWORD data;
	int Timeout = 0x200000;

	if (NoPPFS)
		return -1;

	GPDR &= 0xFE3FFC03;			/* in: GP2:9, GP22:24 */
	GPDR |= 0x00300000;			/* out: GP20:21 */

	GPSR = GPIO_DIR_MASK;			/* direction: in (GPIO_DIR = 1) */
	GPCR = GPIO_WT_MASK;			/* nWT = 0 */

	while ((GPLR & 0x00C00000) && --Timeout) ;	/* wait for data (nWR = nDS = 0) */
	if (!Timeout) {
		NoPPFS = TRUE;
		return -1;
	}

	data = (GPLR >> 2) & 0xFF;		/* data = GP2:9 */
	GPSR = GPIO_WT_MASK;			/* nWT = 1 */

	switch (PP_Protocol) {
		case PP_PROTOCOL_MSCEPB:
			while ((!(GPLR & GPIO_WR_MASK)) && --Timeout) ;	/* wait for nWR = 1 */
			break;
		case PP_PROTOCOL_EPP:
		default:
			while ((!(GPLR & GPIO_DS_MASK)) && --Timeout) ;	/* wait for nDS = 1 */
	}

	if (!Timeout) {
		NoPPFS = TRUE;
		return -1;
	}

	GPCR = GPIO_WT_MASK;			/* nWT = 0 */

	return data;
#else /* (WID == EI370) */
	NoPPFS = TRUE;
	return -1;
#endif /* (WID == EI370) */
}

void
OEMParallelPortSendByte( BYTE ch )
{
#if (WID == EI370)
	DWORD data = ch;
	int Timeout = 0x200000;

	if (NoPPFS)
		return;

	GPDR &= 0xFE3FFFFF;			/* in: GP22:24 */
	GPDR |= 0x003003FC;			/* out: GP2:9, GP20:21 */

	GPCR = GPIO_DIR_MASK;			/* direction: out (GPIO_DIR = 0) */
	GPCR = GPIO_WT_MASK;			/* nWT = 0 */

	switch (PP_Protocol) {
		case PP_PROTOCOL_MSCEPB:
			/* wait for nWR = 1, nDS = 1 */
			while (((GPLR & 0x00C00000) != 0x00C00000) && --Timeout) ;
			break;
		case PP_PROTOCOL_EPP:
		default:
			/* wait for nWR = 1, nDS = 0 */
			while (((GPLR & 0x00C00000) != 0x00400000) && --Timeout) ;
	}

	if (!Timeout) {
		NoPPFS = TRUE;
		return;
	}

	GPSR = data << 2;
	GPCR = ((~data) & 0xFF) << 2;		/* set data (GP2:9) */

	GPSR = GPIO_WT_MASK;			/* nWT = 1 */

	switch (PP_Protocol) {
		case PP_PROTOCOL_MSCEPB:
			while ((GPLR & GPIO_DS_MASK) && --Timeout) ;	/* wait for nDS = 0 */
			break;
		case PP_PROTOCOL_EPP:
		default:
			while ((!(GPLR & GPIO_DS_MASK)) && --Timeout) ;	/* wait for nDS = 1 */
	}

	if (!Timeout) {
		NoPPFS = TRUE;
		return;
	}

	GPCR = GPIO_WT_MASK;			/* nWT = 0 */
#else /* (WID == EI370) */
	UNREFERENCED_PARAMETER( ch );
	NoPPFS = TRUE;
#endif /* (WID == EI370) */
}