mdppfs.c

WinCE 3.0 BSP, 包含Inter SA1110, Intel_815E, Advantech_PCM9574 等

/*++
THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
PARTICULAR PURPOSE.
Copyright (c) 1995, 1996, 1997  Microsoft Corporation

Module Name:

   mdppfs.c

Abstract:

   This file implements the NK kernel ppfs client side interface

Notes:

--*/

#include "windows.h"
#include "p2debug.h"

/*
 * Write register in bits 0-7
 * Read register in bits 8-15
 * Control bits (msw only)
 *
 * This side:
 * 0x8000  - Data byte ready (tx)
 * 0x0800  - Ack to ack (noticed other side's ack)
 * 0x2000  - Waiting for byte (rx)
 * Other side:
 * 0x0002  - Ack (noticed this side's byte)
 * 0x0010  - Data byte ready (rx)
 */

typedef volatile DWORD *PVDWORD;    /* pointer to a volatile dword */

BOOL NoPPFS = FALSE;					// parallel port disconnected flag

//***************************************************************************
// OEMParallelPortGetByte - Get byte from parallel port
//
// Input -	none
// Ouput -	if parallel port disconnected, set NoPPFS=TRUE and returns -1
//			else returns byte received from parallel port
//***************************************************************************
int OEMParallelPortGetByte(void)
{
	DWORD dwStatus;						// parallel port status
	unsigned int iWatchdog=0xffffff;	// timeout counter

	//SA-11x0bd does not support parallel port

	NoPPFS=TRUE;
    if (NoPPFS)							// if parallel port disconnected
        return -1;						// do nothing

										// wait for PAR_INTR
	while (!((dwStatus= *(PVDWORD)(PAR_CONTROL_REG)) & PAR_INTR) && --iWatchdog);
    *(PVDWORD)(PAR_CONTROL_REG) = PAR_BUSY | PAR_AUTOEN | PAR_SELECT;

	if (!iWatchdog) {					// if timeout occured
										// display error message
#ifndef BOOT_LOADER
		NKDbgPrintfW(L"OEMParallelPortGetByte: status timeout.\r\n");
#endif
		NoPPFS=TRUE;					// set parallel port to disconnected
        return -1;						// and return failure
	}
    return((dwStatus>>8)&0xff);			// return byte received
}

//***************************************************************************
// OEMParallelPortSendByte - send byte out parallel port
//
// Input -	chData=byte to send
//
// Output -	sets NoPPFS=TRUE if parallel port disconnected
//***************************************************************************
VOID OEMParallelPortSendByte(BYTE chData)
{
	unsigned int iWatchdog=0xffffff;	// timeout counter
										// parallel port status
    DWORD dwStatus = (DWORD)chData | PAR_BUSY_NFAULT | PAR_SELECT;

	//SA-11x0bd does not support parallel port

	NoPPFS=TRUE;

    if (NoPPFS)							// if ppfs disconnected
        return;							// do nothing

										// set direction to write
    *(PVDWORD)(PAR_CONTROL_REG) = dwStatus;

	while (1) {
										// wait for AUTOFD
		while (!((dwStatus= *(PVDWORD)(PAR_CONTROL_REG)) & PAR_AUTOFD) && --iWatchdog);
		if (!iWatchdog) {				// if timeout occurred
										// display error message
#ifndef BOOT_LOADER
			NKDbgPrintfW(L"OEMParallelPortSendByte: status timeout 1.\r\n");
#endif
			NoPPFS=TRUE;				// and disconnect ppfs
			return;
		}
										// read status two more times to debounce
		if (!((dwStatus= *(PVDWORD)(PAR_CONTROL_REG)) & PAR_AUTOFD))
			continue;
		if (((dwStatus= *(PVDWORD)(PAR_CONTROL_REG)) & PAR_AUTOFD))
			break;
	}

    dwStatus |= PAR_EN;					// set PAR_EN
    *(PVDWORD)(PAR_CONTROL_REG) = dwStatus;
    dwStatus |= PAR_NACK;				// set PAR_NACK
    *(PVDWORD)(PAR_CONTROL_REG) = dwStatus;

	while (1) {
										// wait for AUTOFD
		while (((dwStatus= *(PVDWORD)(PAR_CONTROL_REG)) & PAR_AUTOFD) && --iWatchdog);
		if (!iWatchdog) {				// if timeout occurred
										// display error message
#ifndef BOOT_LOADER
			NKDbgPrintfW(L"OEMParallelPortSendByte: status timeout 2.\r\n");
#endif
			NoPPFS=TRUE;				// and disconnect ppfs
			return;
		}
										// read status two more times to debounce
		if (((dwStatus= *(PVDWORD)(PAR_CONTROL_REG)) & PAR_AUTOFD))
			continue;
		if (!((dwStatus= *(PVDWORD)(PAR_CONTROL_REG)) & PAR_AUTOFD))
			break;
	}
										// leave status in read mode
    *(PVDWORD)(PAR_CONTROL_REG) = PAR_BUSY_NFAULT_AUTOEN_SELECT;
}