text: /*	$NetBSD: clock.c,v 1.2 2001/11/08 07:01:33 gmcgarry Exp $	*/
  
  /*
   * Copyright (c) 1988 University of Utah.
   * Copyright (c) 1982, 1990, 1993
   *	The Regents of the University of California.  All rights reserved.
   *
   * This code is derived from software contributed to Berkeley by
   * the Systems Programming Group of the University of Utah Computer
   * Science Department.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   * from: Utah $Hdr: clock.c 1.18 91/01/21$
   *
   *	@(#)clock.c	8.2 (Berkeley) 1/12/94
   */
  
  #include <sys/param.h>
  
  #include <hp300/dev/hilreg.h>
  
  #define FEBRUARY        2
  #define STARTOFTIME     1970
  #define SECDAY          86400L
  #define SECYR           (SECDAY * 365)
  
  #define BBC_SET_REG     0xe0
  #define BBC_WRITE_REG   0xc2
  #define BBC_READ_REG    0xc3
  #define NUM_BBC_REGS    12
  
  #define leapyear(year)		((year) % 4 == 0)
  #define range_test(n, l, h)	if ((n) < (l) || (n) > (h)) return(0)
  #define days_in_year(a)		(leapyear(a) ? 366 : 365)
  #define days_in_month(a)	(month_days[(a) - 1])
  #define bbc_to_decimal(a,b)	(bbc_registers[a] * 10 + bbc_registers[b])
  
  #include <hp300/stand/common/samachdep.h>
  
  static int month_days[12] = {
  	31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
  };
  
  u_char bbc_registers[13];
  u_char read_bbc_reg();
  struct hil_dev *bbcaddr = BBCADDR;
  
  getsecs()
  {
  	static int bbcinited = 0;
  	u_long timbuf = 0;
  
  	if (!bbc_to_gmt(&timbuf) && !bbcinited)
  		printf("WARNING: bad date in battery clock\n");
  	bbcinited = 1;
  
  	/* Battery clock does not store usec's, so forget about it. */
  	return(timbuf);
  }
  
  
  bbc_to_gmt(timbuf)
  	u_long *timbuf;
  {
  	register int i;
  	register u_long tmp;
  	int year, month, day, hour, min, sec;
  
  	read_bbc();
  
  	sec = bbc_to_decimal(1, 0);
  	min = bbc_to_decimal(3, 2);
  
  	/*
  	 * Hours are different for some reason. Makes no sense really.
  	 */
  	hour  = ((bbc_registers[5] & 0x03) * 10) + bbc_registers[4];
  	day   = bbc_to_decimal(8, 7);
  	month = bbc_to_decimal(10, 9);
  	year  = bbc_to_decimal(12, 11) + 1900;
  
  	range_test(hour, 0, 23);
  	range_test(day, 1, 31);
  	range_test(month, 1, 12);
  	range_test(year, STARTOFTIME, 2000);
  
  	tmp = 0;
  
  	for (i = STARTOFTIME; i < year; i++)
  		tmp += days_in_year(i);
  	if (leapyear(year) && month > FEBRUARY)
  		tmp++;
  
  	for (i = 1; i < month; i++)
  	  	tmp += days_in_month(i);
  	
  	tmp += (day - 1);
  	tmp = ((tmp * 24 + hour) * 60 + min) * 60 + sec;
  
  	*timbuf = tmp;
  	return(1);
  }
  
  read_bbc()
  {
    	register int i, read_okay;
  
  	read_okay = 0;
  	while (!read_okay) {
  		read_okay = 1;
  		for (i = 0; i <= NUM_BBC_REGS; i++)
  			bbc_registers[i] = read_bbc_reg(i);
  		for (i = 0; i <= NUM_BBC_REGS; i++)
  			if (bbc_registers[i] != read_bbc_reg(i))
  				read_okay = 0;
  	}
  }
  
  u_char
  read_bbc_reg(reg)
  	int reg;
  {
  	u_char data = reg;
  
  	if (bbcaddr) {
  #if 0
  		send_hil_cmd(bbcaddr, BBC_SET_REG, &data, 1, NULL);
  		send_hil_cmd(bbcaddr, BBC_READ_REG, NULL, 0, &data);
  #else
  		HILWAIT(bbcaddr);
  		bbcaddr->hil_cmd = BBC_SET_REG;
  		HILWAIT(bbcaddr);
  		bbcaddr->hil_data = data;
  		HILWAIT(bbcaddr);
  		bbcaddr->hil_cmd = BBC_READ_REG;
  		HILDATAWAIT(bbcaddr);
  		data = bbcaddr->hil_data;
  #endif
  	}
  	return(data);
  }
  