/*-------------------------------------------------------------------------+
| rtc.c v1.1 - PC386 BSP - 1997/08/07
+--------------------------------------------------------------------------+
| This file contains the real time clock manipulation package for the
| PC386 board.
+--------------------------------------------------------------------------+
| (C) Copyright 1997 -
| - NavIST Group - Real-Time Distributed Systems and Industrial Automation
|
| http://pandora.ist.utl.pt
|
| Instituto Superior Tecnico * Lisboa * PORTUGAL
+--------------------------------------------------------------------------+
| Disclaimer:
|
| This file is provided "AS IS" without warranty of any kind, either
| expressed or implied.
+--------------------------------------------------------------------------+
| This code is based on:
| rtc.c,v 1.4 1995/12/19 20:07:15 joel Exp - go32 BSP
| With the following copyright notice:
| **************************************************************************
| * COPYRIGHT (c) 1989-1999.
| * On-Line Applications Research Corporation (OAR).
| *
| * The license and distribution terms for this file may be
| * found in found in the file LICENSE in this distribution or at
| * http://www.OARcorp.com/rtems/license.html.
| **************************************************************************
|
| $Id$
+--------------------------------------------------------------------------*/
#include <string.h>
#include <bsp.h>
/*-------------------------------------------------------------------------+
| Constants
+--------------------------------------------------------------------------*/
#define IO_RTC 0x70 /* RTC */
#define RTC_SEC 0x00 /* seconds */
#define RTC_SECALRM 0x01 /* seconds alarm */
#define RTC_MIN 0x02 /* minutes */
#define RTC_MINALRM 0x03 /* minutes alarm */
#define RTC_HRS 0x04 /* hours */
#define RTC_HRSALRM 0x05 /* hours alarm */
#define RTC_WDAY 0x06 /* week day */
#define RTC_DAY 0x07 /* day of month */
#define RTC_MONTH 0x08 /* month of year */
#define RTC_YEAR 0x09 /* month of year */
#define RTC_STATUSA 0x0a /* status register A */
#define RTCSA_TUP 0x80 /* time update, don't look now */
#define RTC_STATUSB 0x0b /* status register B */
#define RTC_INTR 0x0c /* status register C (R) interrupt source */
#define RTCIR_UPDATE 0x10 /* update intr */
#define RTCIR_ALARM 0x20 /* alarm intr */
#define RTCIR_PERIOD 0x40 /* periodic intr */
#define RTCIR_INT 0x80 /* interrupt output signal */
#define RTC_STATUSD 0x0d /* status register D (R) Lost Power */
#define RTCSD_PWR 0x80 /* clock lost power */
#define RTC_DIAG 0x0e /* status register E - bios diagnostic */
#define RTCDG_BITS "\020\010clock_battery\007ROM_cksum\006config_unit\005memory_size\004fixed_disk\003invalid_time"
#define RTC_CENTURY 0x32 /* current century - increment in Dec99 */
/*-------------------------------------------------------------------------+
| Auxiliary Functions
+--------------------------------------------------------------------------*/
/*-------------------------------------------------------------------------+
| Function: bcd
| Description: Convert 2 digit number to its BCD representation.
| Global Variables: None.
| Arguments: i - Number to convert.
| Returns: BCD representation of number.
+--------------------------------------------------------------------------*/
static inline rtems_unsigned8
bcd(rtems_unsigned8 i)
{
return ((i / 16) * 10 + (i % 16));
} /* bcd */
#define QUICK_READ /* Quick read of the RTC: don't return number of seconds. */
#ifndef QUICK_READ
#define SECS_PER_DAY (24 * 60 * 60)
#define SECS_PER_REG_YEAR (365 * SECS_PER_DAY)
/*-------------------------------------------------------------------------+
| Function: ytos
| Description: Convert years to seconds (since 1970).
| Global Variables: None.
| Arguments: y - year to convert (1970 <= y <= 2100).
| Returns: number of seconds since 1970.
+--------------------------------------------------------------------------*/
static inline rtems_unsigned32
ytos(rtems_unsigned16 y)
{ /* v NUM LEAP YEARS v */
return ((y - 1970) * SECS_PER_REG_YEAR + (y - 1970 + 1) / 4 * SECS_PER_DAY);
} /* ytos */
/*-------------------------------------------------------------------------+
| Function: mtos
| Description: Convert months to seconds since January.
| Global Variables: None.
| Arguments: m - month to convert, leap - is this a month of a leap year.
| Returns: number of seconds since January.
+--------------------------------------------------------------------------*/
static inline rtems_unsigned32
mtos(rtems_unsigned8 m, rtems_boolean leap)
{
static rtems_unsigned16 daysMonth[] = { 0, 0, 31, 59, 90, 120, 151, 181,
212, 243, 273, 304, 334, 365 };
/* Days since beginning of year until beginning of month. */
return ((daysMonth[m] + (leap ? 1 : 0)) * SECS_PER_DAY);
} /* mtos */
#endif /* QUICK_READ */
/*-------------------------------------------------------------------------+
| Function: rtcin
| Description: Perform action on RTC and return its result.
| Global Variables: None.
| Arguments: what - what to write to RTC port (what to do).
| Returns: result received from RTC port after action performed.
+--------------------------------------------------------------------------*/
static inline rtems_unsigned8
rtcin(rtems_unsigned8 what)
{
rtems_unsigned8 r;
outport_byte(IO_RTC, what);
inport_byte (IO_RTC+1, r);
return r;
} /* rtcin */
/*-------------------------------------------------------------------------+
| Functions
+--------------------------------------------------------------------------*/
/*-------------------------------------------------------------------------+
| Function: init_rtc
| Description: Initialize real-time clock (RTC).
| Global Variables: None.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
void
init_rtc(void)
{
rtems_unsigned8 s;
/* initialize brain-dead battery powered clock */
outport_byte(IO_RTC, RTC_STATUSA);
outport_byte(IO_RTC+1, 0x26);
outport_byte(IO_RTC, RTC_STATUSB);
outport_byte(IO_RTC+1, 2);
outport_byte(IO_RTC, RTC_DIAG);
inport_byte (IO_RTC+1, s);
if (s)
printk("RTC BIOS diagnostic error %b\n", s);
/* FIXME: This was last line's original version. How was it supposed to work?
printf("RTC BIOS diagnostic error %b\n", s, RTCDG_BITS); */
} /* init_rtc */
/*-------------------------------------------------------------------------+
| Function: rtc_read
| Description: Read present time from RTC and return it.
| Global Variables: None.
| Arguments: tod - to return present time in 'rtems_time_of_day' format.
| Returns: number of seconds from 1970/01/01 corresponding to 'tod'.
+--------------------------------------------------------------------------*/
long int
rtc_read(rtems_time_of_day *tod)
{
rtems_unsigned8 sa;
rtems_unsigned32 sec = 0;
memset(tod, 0, sizeof *tod); /* zero tod structure */
/* do we have a realtime clock present? (otherwise we loop below) */
sa = rtcin(RTC_STATUSA);
if (sa == 0xff || sa == 0)
return -1;
/* ready for a read? */
while ((sa&RTCSA_TUP) == RTCSA_TUP)
sa = rtcin(RTC_STATUSA);
tod->year = bcd(rtcin(RTC_YEAR)) + 1900; /* year */
if (tod->year < 1970) tod->year += 100;
tod->month = bcd(rtcin(RTC_MONTH)); /* month */
tod->day = bcd(rtcin(RTC_DAY)); /* day */
(void) bcd(rtcin(RTC_WDAY)); /* weekday */
tod->hour = bcd(rtcin(RTC_HRS)); /* hour */
tod->minute = bcd(rtcin(RTC_MIN)); /* minutes */
tod->second = bcd(rtcin(RTC_SEC)); /* seconds */
tod->ticks = 0;
#ifndef QUICK_READ /* Quick read of the RTC: don't return number of seconds. */
sec = ytos(tod->year);
sec += mtos(tod->month, (tod->year % 4) == 0);
sec += tod->day * SECS_PER_DAY;
sec += tod->hour * 60 * 60; /* hour */
sec += tod->minute * 60; /* minutes */
sec += tod->second; /* seconds */
#endif /* QUICK_READ */
return (long int)sec;
} /* rtc_read */
