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root/bsp/drv/dev/rtc/rtc.c

DEFINITIONS

1. leapyear
2. rtc_ymdhms_to_secs
3. rtc_secs_to_ymdhms
4. rtc_ioctl
5. rtc_attach
6. rtc_init

   1 /*
   2  * Copyright (c) 1988 University of Utah.
   3  * Copyright (c) 1982, 1990, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * This code is derived from software contributed to Berkeley by
   7  * the Systems Programming Group of the University of Utah Computer
   8  * Science Department.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * from: Utah $Hdr: clock.c 1.18 91/01/21$
  35  *
  36  *      @(#)clock.c     8.2 (Berkeley) 1/12/94
  37  */
  39 /* Modified for Prex by Kohsuke Ohtani */
  41 /*
  42  * rtc.c - machine independent RTC driver
  43  */
  45 #include <sys/time.h>
  46 #include <sys/ioctl.h>
  48 #include <driver.h>
  49 #include <rtc.h>
  51 #define FEBRUARY        2
  52 #define days_in_year(a)         (leapyear(a) ? 366 : 365)
  53 #define days_in_month(a)        (month_days[(a) - 1])
  55 struct rtc_softc {
device_t        dev;            /* device object */
  57         struct rtc_ops  *ops;           /* rtc operations */
  58         void            *aux;           /* cookie data */
time_t          boot_sec;       /* Time (sec) at system boot */
u_long          boot_ticks;     /* Time (ticks) at system boot */
  61 };
  63 static int rtc_ioctl(device_t, u_long, void *);
  64 static int rtc_init(struct driver *);
  66 static struct devops rtc_devops = {
  67         /* open */      no_open,
  68         /* close */     no_close,
  69         /* read */      no_read,
  70         /* write */     no_write,
  71         /* ioctl */     rtc_ioctl,
  72         /* devctl */    no_devctl,
  73 };
  75 struct driver rtc_driver = {
  76         /* name */      "rtc",
  77         /* devops */    &rtc_devops,
  78         /* devsz */     sizeof(struct rtc_softc),
  79         /* flags */     0,
  80         /* probe */     NULL,
  81         /* init */      rtc_init,
  82         /* shutdown */  NULL,
  83 };
  85 static const int month_days[12] = {
  86         31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
  87 };
  89 static int
leapyear(u_int year)
  91 {
  92         int rv = 0;
  94         if ((year & 3) == 0) {
rv = 1;
  96                 if ((year % 100) == 0) {
rv = 0;
  98                         if ((year % 400) == 0)
rv = 1;
 100                 }
 101         }
 102         return (rv);
 103 }
time_t
rtc_ymdhms_to_secs(struct clock_ymdhms *dt)
 107 {
time_t secs;
u_int i, year, days;
year = dt->year;
 113         /*
 114          * Compute days since start of time.
 115          * First from years, then from months.
 116          */
days = 0;
 118         for (i = POSIX_BASE_YEAR; i < year; i++)
days += days_in_year(i);
 120         if (leapyear(year) && dt->mon > FEBRUARY)
days++;
 123         /* Months */
 124         for (i = 1; i < dt->mon; i++)
days += days_in_month(i);
days += (dt->day - 1);
 128         /* Add hours, minutes, seconds. */
secs = (time_t)(((days * 24 + dt->hour) * 60 + dt->min)
 130                         * 60 + dt->sec);
 132         return (secs);
 133 }
 135 /* This function uses a copy of month_days[] */
 136 #undef  days_in_month
 137 #define days_in_month(a)        (mthdays[(a) - 1])
 139 void
rtc_secs_to_ymdhms(time_t secs, struct clock_ymdhms *dt)
 141 {
u_int mthdays[12];
u_int i, days;
u_int rsec;     /* remainder seconds */
memcpy(mthdays, month_days, sizeof(mthdays));
days = secs / SECDAY;
rsec = secs % SECDAY;
 151         /* Day of week (Note: 1/1/1970 was a Thursday) */
dt->dow = (days + 4) % 7;
 154         /* Subtract out whole years, counting them in i. */
 155         for (i = POSIX_BASE_YEAR; days >= days_in_year(i); i++)
days -= days_in_year(i);
dt->year = (u_short)i;
 159         /* Subtract out whole months, counting them in i. */
 160         if (leapyear(i))
days_in_month(FEBRUARY) = 29;
 162         for (i = 1; days >= days_in_month(i); i++)
days -= days_in_month(i);
dt->mon = i;
 166         /* Days are what is left over (+1) from all that. */
dt->day = days + 1;
 169         /* Hours, minutes, seconds are easy */
dt->hour = rsec / 3600;
rsec = rsec % 3600;
dt->min  = rsec / 60;
rsec = rsec % 60;
dt->sec  = rsec;
 175 }
 177 static int
rtc_ioctl(device_t dev, u_long cmd, void *arg)
 179 {
 180         struct rtc_softc *sc = device_private(dev);
 181         struct timeval tv;
 182         int error = 0;
u_long msec;
 185         switch (cmd) {
 186         case RTCIOC_GET_TIME:
 187                 /*
 188                  * Calculate current time (sec/usec) from
 189                  * boot time and current tick count.
 190                  */
msec = hztoms(timer_ticks() - sc->boot_ticks);
tv.tv_sec = sc->boot_sec + (msec / 1000);
tv.tv_usec = (long)((msec * 1000) % 1000000);
 194                 if (copyout(&tv, arg, sizeof(tv)))
 195                         return EFAULT;
 196                 break;
 198         case RTCIOC_SET_TIME:
 199                 /*
 200                  * TODO: We need new capability to set time.
 201                  */
error = EINVAL;
 203                 break;
 204         default:
 205                 return EINVAL;
 206         }
 207         return error;
 208 }
 210 void
rtc_attach(struct rtc_ops *ops, void *aux)
 212 {
 213         struct rtc_softc *sc;
device_t dev;
 215         struct timeval tv;
dev = device_create(&rtc_driver, "rtc", D_CHR);
sc = device_private(dev);
sc->dev = dev;
sc->ops = ops;
sc->aux = aux;
 224         /* Save boot time for later use. */
ops->gettime(aux, &tv);
sc->boot_sec = tv.tv_sec;
sc->boot_ticks = timer_ticks();
 228 }
 230 static int
rtc_init(struct driver *self)
 232 {
 234         return 0;
 235 }