// Bit/Byte utility operations for myparport driver
// Author: Jayanta Konjengbam
// All rights reserved

#include "stddcls.h"
#include "BitUtilsWdm.h"

/* Verify if the bit field indicated by mask/offset is high */
BOOLEAN IsBitSet(UCHAR byte, UCHAR bitMask)	{
	return ((byte & bitMask) ? TRUE : FALSE);
}

/* Put the bit field indicated by flag mask/offset to high, if low */
UCHAR SetBit(UCHAR byteValue, UCHAR bitMask) {
	if (!IsBitSet(byteValue, bitMask)) return (0x00|(byteValue | (bitMask)));
	return byteValue;
}

/* Multiple bits can be set at one go using this function */
VOID SetBits(PUCHAR pByteValue, UCHAR bitMasks) {
	USHORT i = 0;

	for(i=0;i<MASKS_ARRAY_LEN;i++)
		if(bitMasks & BIT_MASKS_ARRAY[i]) 
			*pByteValue = SetBit((*pByteValue), BIT_MASKS_ARRAY[i]);
}

/* Put the bit field indicated by mask/offset to low, if high */
UCHAR ClearBit(UCHAR byteValue, UCHAR bitMask) {
	if (IsBitSet(byteValue, bitMask)) {
		UCHAR byteTmp = byteValue & (0x00|(~(byteValue & bitMask)));
		return byteTmp;
	}
	return byteValue;
}

/* Toggle the bit field specified by input mask/offset */
UCHAR ToggleBit(UCHAR byteValue, UCHAR bitMask) {
	if (IsBitSet(byteValue, bitMask)) 
		return ClearBit(byteValue, bitMask);

	return SetBit(byteValue, bitMask);
}

/* Swap bits of a given byte number */
UCHAR SwapBits(UCHAR byteValue) {
	UCHAR byteTmp = 0x00;

	byteTmp = (0x00 | ((byteValue & BIT_0_SET) << 7));
	byteTmp |= (0x00 | ((byteValue & BIT_1_SET) << 5));
	byteTmp |= (0x00 | ((byteValue & BIT_2_SET) << 3));
	byteTmp |= (0x00 | ((byteValue & BIT_3_SET) << 1));
	byteTmp |= (0x00 | ((byteValue & BIT_4_SET) >> 1));
	byteTmp |= (0x00 | ((byteValue & BIT_5_SET) >> 3));
	byteTmp |= (0x00 | ((byteValue & BIT_6_SET) >> 5));
	byteTmp |= (0x00 | ((byteValue & BIT_7_SET) >> 7));

	return byteTmp;
}

PCHAR AllocByteToBinaryStr(UCHAR byteValue)
{
#define BYTE_SIZE 8 // Eight bit fields

	const CHAR HIGH = '1';
	const CHAR LOW = '0';

	PCHAR	pTmp = NULL;
	USHORT	index = 0;
	BOOLEAN BitHigh = FALSE;

	// User must free this allocation
	pTmp = (PCHAR)ExAllocatePool(NonPagedPool, sizeof(CHAR)*(BYTE_SIZE+1));
	if (!pTmp) return NULL;

	for(index = 0; index < BYTE_SIZE; index++)
	{
		BitHigh = (byteValue & ((UCHAR)BIT_MASKS_ARRAY[index]));
		pTmp[index] = (BitHigh) ? HIGH : LOW;
	}

	// Null terminate the string
	pTmp[index] = '\0'; 
	return pTmp; 
}