/*************************************************************************
* (C) 2010 AITNET ltd - Sofia/Bulgaria - <misho@aitbg.com>
*  by Michael Pounov <misho@openbsd-bg.org>
*
* $Author: misho $
* $Id: pelco.c,v 1.2 2010/01/20 00:15:06 misho Exp $
*
*************************************************************************/
#include "global.h"


/*
 * crcPelco() Calculate Pelco D/P CRC
 * @ver = Pelco protocol version (Dd | Pp)
 * @pkt = Packet for calculate crc
 * return: crc for packet, if is 0 check and crc_GetErrno() == 1 
 	Pelco protocol not supported
 */
inline u_char crcPelco(u_char ver, u_char *pkt)
{
	register u_char i, crc;

	switch (ver) {
		case 'D':
		case 'd':
			for (i = 1, crc = 0; i < 6; crc += pkt[i++]);
			crc %= 0x100;
			break;
		case 'P':
		case 'p':
			for (i = 1, crc = pkt[0]; i < 7; crc ^= pkt[i++]);
			break;
		default:
			crc = 0;
			crcSetErr(1, "crcAdler(): Invalid parameters!");
	}

	return crc;
}