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 static struct spi_slave *slave;
  28
  29 int rtc_get(struct rtc_time *rtc)
  30 {
  31         u32 day1, day2, time;
  32         u32 reg;
  33         int err, tim, i = 0;
  34
  35         if (!slave) {
  36                 /* FIXME: Verify the max SCK rate */
  37                 slave = spi_setup_slave(1, 0, 1000000,
  38                                 SPI_MODE_2 | SPI_CS_HIGH);
  39                 if (!slave)
  40                         return -1;
  41         }
  42
  43         if (spi_claim_bus(slave))
  44                 return -1;
  45
  46         do {
  47                 reg = 0x2c000000;
  48                 err = spi_xfer(slave, 32, (uchar *)&reg, (uchar *)&day1,
  49                                 SPI_XFER_BEGIN | SPI_XFER_END);
  50
  51                 if (err)
  52                         return err;
  53
  54                 reg = 0x28000000;
  55                 err = spi_xfer(slave, 32, (uchar *)&reg, (uchar *)&time,
  56                                 SPI_XFER_BEGIN | SPI_XFER_END);
  57
  58                 if (err)
  59                         return err;
  60
  61                 reg = 0x2c000000;
  62                 err = spi_xfer(slave, 32, (uchar *)&reg, (uchar *)&day2,
  63                                 SPI_XFER_BEGIN | SPI_XFER_END);
  64
  65                 if (err)
  66                         return err;
  67         } while (day1 != day2 && i++ < 3);
  68
  69         spi_release_bus(slave);
  70
  71         tim = day1 * 86400 + time;
  72         to_tm(tim, rtc);
  73
  74         rtc->tm_yday = 0;
  75         rtc->tm_isdst = 0;
  76
  77         return 0;
  78 }
  79
  80 void rtc_set(struct rtc_time *rtc)
  81 {
  82         u32 time, day, reg;
  83
  84         if (!slave) {
  85                 /* FIXME: Verify the max SCK rate */
  86                 slave = spi_setup_slave(1, 0, 1000000,
  87                                 SPI_MODE_2 | SPI_CS_HIGH);
  88                 if (!slave)
  89                         return;
  90         }
  91
  92         time = mktime(rtc->tm_year, rtc->tm_mon, rtc->tm_mday,
  93                       rtc->tm_hour, rtc->tm_min, rtc->tm_sec);
  94         day = time / 86400;
  95         time %= 86400;
  96
  97         if (spi_claim_bus(slave))
  98                 return;
  99
 100         reg = 0x2c000000 | day | 0x80000000;
 101         spi_xfer(slave, 32, (uchar *)&reg, (uchar *)&day,
 102                         SPI_XFER_BEGIN | SPI_XFER_END);
 103
 104         reg = 0x28000000 | time | 0x80000000;
 105         spi_xfer(slave, 32, (uchar *)&reg, (uchar *)&time,
 106                         SPI_XFER_BEGIN | SPI_XFER_END);
 107
 108         spi_release_bus(slave);
 109 }
 110
 111 void rtc_reset(void)
 112 {
 113 }