/*********************************************************************
	DS1307.C		JC Bertin, Mipsys
	03/22/2000

	This file handles the Dallas DS1307 Real Time Clock on Horoscas
	board.

	It use the mbus driver to communicate with the DS1307.
**********************************************************************/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <getopt.h>
#include <fcntl.h>
#include "ds1302.h"

#define DS1307_ADDR		0xd0

static int mbus_fd;

/*******************************************************************
	Setup_1302_Port
	
	Initialize Port Pins to access DS1302 Clock.

	Note that all three pins are defined initialliy as outputs.
	When you want to read a port pin, you have to turn it
	around.

	MCF5206...
	PP0 = CLOCK
	PP1 = RST*
	PP2 = DATA
********************************************************************/
void Setup_1302_Port(void)
{
	if ((mbus_fd = open("/dev/mbus", O_RDWR)) < 0) {
		perror("/dev/mbus");
		exit(1);
	}
}

/*******************************************************************
	Lock_1302

	This routine will LOCK the clock and stop its oscillator to
	preserve Battery Life.
	Uses TimeBuffer[] as temporary storage.
********************************************************************/
void Lock_1302 (void)
{
	int result;
	unsigned char buffer[4];				//temp storage

	buffer[0] = DS1307_ADDR;
	buffer[1] = 0;
	if ((result = read(mbus_fd, buffer, 3)) != 3) {
		fprintf(stderr, "DS1307 returned %d\n", result);
		exit(1);
	}
	buffer[2] |= 0x80;
	if ((result = write(mbus_fd, buffer, 3)) != 3) {
		fprintf(stderr, "DS1307 returned %d\n", result);
		exit(1);
	}
} /* end proc Lock_1203() */


/*******************************************************************
	Set_Time

	This routine SETs the clock and start its oscillator, write-
	protecting the clock registers.
	Obtains time from TimeBuffer[].
********************************************************************/
void Set_Time(unsigned char * TimeBuffer)
{
   int result;
   unsigned char buffer[10];

   TimeBuffer[7] = '\x80';         //write protect the chip after write
   buffer[0] = DS1307_ADDR;
   buffer[1] = 0;
   memcpy(&buffer[2], TimeBuffer, 8);

   if ((result = write(mbus_fd, buffer, 10)) != 10) {
	   fprintf(stderr, "DS1307 returned %d\n", result);
	   exit(1);
   }
} /* end proc Set_Time() */

/*******************************************************************
	Get_Time

	This routine GETs the time from the Dallas 1302 clock.
	The time is returned in TimeBuffer.
	This function returns 0 when the clock is operating properly.
	If the clock was locked (stopped) the default time is returned
	as 1/1/99, 12:00Noon and the function returns non-zero.
********************************************************************/
unsigned int Get_Time(unsigned char * TimeBuffer)
{
	unsigned int clock_locked;
	int result;
	unsigned char buffer[10];

	buffer[0] = DS1307_ADDR;
	buffer[1] = 0;
	if ((result = read(mbus_fd, buffer, 10)) != 10) {
		fprintf(stderr, "DS1307 returned %d\n", result);
		exit(1);
	}
	memcpy(TimeBuffer, &buffer[2], 8);
	clock_locked = ((TimeBuffer[0] & 0x80) != 0);
	return(clock_locked);
} /* end proc Get_Time() */