drivers/rtc/mc13783-rtc.c

   1 /*
   2  * Copyright (C) 2008, Guennadi Liakhovetski <lg@denx.de>
   3  *
   4  * See file CREDITS for list of people who contributed to this
   5  * project.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of
  10  * the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  20  * MA 02111-1307 USA
  21  */
  22
  23 #include <common.h>
  24 #include <rtc.h>
  25 #include <spi.h>
  26
  27 int rtc_get(struct rtc_time *rtc)
  28 {
  29         u32 day1, day2, time;
  30         u32 reg;
  31         int err, tim, i = 0;
  32
  33         spi_select(1, 0, SPI_MODE_2 | SPI_CS_HIGH);
  34
  35         do {
  36                 reg = 0x2c000000;
  37                 err = spi_xfer(0, 32, (uchar *)&reg, (uchar *)&day1);
  38
  39                 if (err)
  40                         return err;
  41
  42                 reg = 0x28000000;
  43                 err = spi_xfer(0, 32, (uchar *)&reg, (uchar *)&time);
  44
  45                 if (err)
  46                         return err;
  47
  48                 reg = 0x2c000000;
  49                 err = spi_xfer(0, 32, (uchar *)&reg, (uchar *)&day2);
  50
  51                 if (err)
  52                         return err;
  53         } while (day1 != day2 && i++ < 3);
  54
  55         tim = day1 * 86400 + time;
  56         to_tm(tim, rtc);
  57
  58         rtc->tm_yday = 0;
  59         rtc->tm_isdst = 0;
  60
  61         return 0;
  62 }
  63
  64 void rtc_set(struct rtc_time *rtc)
  65 {
  66         u32 time, day, reg;
  67
  68         time = mktime(rtc->tm_year, rtc->tm_mon, rtc->tm_mday,
  69                       rtc->tm_hour, rtc->tm_min, rtc->tm_sec);
  70         day = time / 86400;
  71         time %= 86400;
  72
  73         reg = 0x2c000000 | day | 0x80000000;
  74         spi_xfer(0, 32, (uchar *)&reg, (uchar *)&day);
  75
  76         reg = 0x28000000 | time | 0x80000000;
  77         spi_xfer(0, 32, (uchar *)&reg, (uchar *)&time);
  78 }
  79
  80 void rtc_reset(void)
  81 {
  82 }