/*-
* Copyright (c) 2005, Kohsuke Ohtani
* All rights reserved.
*
* 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. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
/*
* rtc.c - Real time clock driver
*/
#include <sys/time.h>
#include <sys/ioctl.h>
#include <driver.h>
#include <cpufunc.h>
/* Cmos */
#define CMOS_INDEX 0x70
#define CMOS_DATA 0x71
/* CMOS address */
#define CMOS_SEC 0x00
#define CMOS_MIN 0x02
#define CMOS_HOUR 0x04
#define CMOS_DAY 0x07
#define CMOS_MON 0x08
#define CMOS_YEAR 0x09
#define CMOS_STS_A 0x0a
#define CMOS_UIP 0x80
#define CMOS_STS_B 0x0b
#define CMOS_BCD 0x04
#define DAYSPERYEAR (31+28+31+30+31+30+31+31+30+31+30+31)
static int rtc_read(device_t dev, char *buf, size_t *nbyte, int blkno);
static int rtc_ioctl(device_t dev, u_long cmd, void *arg);
static int rtc_init(void);
/*
* Driver structure
*/
struct driver rtc_drv = {
/* name */ "Realtime Clock",
/* order */ 4,
/* init */ rtc_init,
};
/*
* Device I/O table
*/
static struct devio rtc_io = {
/* open */ NULL,
/* close */ NULL,
/* read */ rtc_read,
/* write */ NULL,
/* ioctl */ rtc_ioctl,
/* event */ NULL,
};
static const int daysinmonth[] =
{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
static device_t rtc_dev; /* Device object */
static u_long boot_sec; /* Time (sec) at system boot */
static u_long boot_ticks; /* Time (ticks) at system boot */
static u_int
cmos_read(int index)
{
u_int value;
irq_lock();
outb(index, CMOS_INDEX);
value = inb(CMOS_DATA);
irq_unlock();
return value;
}
/*
static void
cmos_write(int index, int value)
{
irq_lock();
outb(index, CMOS_INDEX);
outb(value, CMOS_DATA);
irq_unlock();
}
*/
static u_int
bcd2bin(u_int bcd)
{
return (bcd & 0x0f) + ((bcd >> 4) & 0xf) * 10;
}
/*
static int bin2bcd(int bin)
{
return ((bin / 10) << 4) + (bin % 10);
}
*/
static int
is_leap(u_int year)
{
if ((year % 4 == 0) && (year % 100 != 0))
return 1;
if (year % 400 == 0)
return 1;
return 0;
}
/*
* Return current seconds (seconds since Epoch 1970/1/1 0:0:0)
*/
static u_long
cmos_gettime(void)
{
u_int sec, min, hour, day, mon, year;
u_int i;
u_int days;
/* Wait until data ready */
for (i = 0; i < 1000000; i++)
if (!(cmos_read(CMOS_STS_A) & CMOS_UIP))
break;
sec = cmos_read(CMOS_SEC);
min = cmos_read(CMOS_MIN);
hour = cmos_read(CMOS_HOUR);
day = cmos_read(CMOS_DAY);
mon = cmos_read(CMOS_MON);
year = cmos_read(CMOS_YEAR);
if (!(cmos_read(CMOS_STS_B) & CMOS_BCD)) {
sec = bcd2bin(sec);
min = bcd2bin(min);
hour = bcd2bin(hour);
day = bcd2bin(day);
mon = bcd2bin(mon);
year = bcd2bin(year);
}
if (year < 80)
year += 2000;
else
year += 1900;
#ifdef DEBUG
printf("rtc: system time was %d/%d/%d %d:%d:%d\n",
year, mon, day, hour, min, sec);
#endif
days = 0;
for (i = 1970; i < year; i++)
days += DAYSPERYEAR + is_leap(i);
for (i = 1; i < mon; i++)
days += daysinmonth[i - 1];
if ((mon > 2) && is_leap(year))
days++;
days += day - 1;
sec = (((days * 24 + hour) * 60) + min) * 60 + sec;
return sec;
}
static int
rtc_read(device_t dev, char *buf, size_t *nbyte, int blkno)
{
u_long time;
if (*nbyte < sizeof(u_long))
return 0;
time = cmos_gettime();
if (umem_copyout(&time, buf, sizeof(u_long)))
return EFAULT;
*nbyte = sizeof(u_long);
return 0;
}
static int
rtc_ioctl(device_t dev, u_long cmd, void *arg)
{
struct timeval tv;
int err = 0;
u_long msec;
switch (cmd) {
case RTCIOC_GET_TIME:
/*
* Calculate current time (sec/usec) from
* boot time and current tick count.
*/
msec = tick_to_msec(timer_count() - boot_ticks);
tv.tv_sec = (long)(boot_sec + (msec / 1000));
tv.tv_usec = (long)((msec * 1000) % 1000000);
if (umem_copyout(&tv, arg, sizeof(tv)))
return EFAULT;
break;
case RTCIOC_SET_TIME:
err = EINVAL;
break;
default:
return EINVAL;
}
return err;
}
/*
* Initialize
*/
static int
rtc_init(void)
{
/* Create device object */
rtc_dev = device_create(&rtc_io, "rtc", DF_CHR);
ASSERT(rtc_dev);
boot_sec = cmos_gettime();
boot_ticks = timer_count();
return 0;
}