/*-------------------------------------------------------------------------+ | 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.rtems.com/license/LICENSE. | ************************************************************************** | | $Id$ +--------------------------------------------------------------------------*/ #include #include /*-------------------------------------------------------------------------+ | 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 */