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(CONFIG_MC13783_SPI_BUS,
  38                                 CONFIG_MC13783_SPI_CS, 1000000,
  39                                 SPI_MODE_2 | SPI_CS_HIGH);
  40                 if (!slave)
  41                         return -1;
  42         }
  43
  44         if (spi_claim_bus(slave))
  45                 return -1;
  46
  47         do {
  48                 reg = 0x2c000000;
  49                 err = spi_xfer(slave, 32, (uchar *)&reg, (uchar *)&day1,
  50                                 SPI_XFER_BEGIN | SPI_XFER_END);
  51
  52                 if (err)
  53                         return err;
  54
  55                 reg = 0x28000000;
  56                 err = spi_xfer(slave, 32, (uchar *)&reg, (uchar *)&time,
  57                                 SPI_XFER_BEGIN | SPI_XFER_END);
  58
  59                 if (err)
  60                         return err;
  61
  62                 reg = 0x2c000000;
  63                 err = spi_xfer(slave, 32, (uchar *)&reg, (uchar *)&day2,
  64                                 SPI_XFER_BEGIN | SPI_XFER_END);
  65
  66                 if (err)
  67                         return err;
  68         } while (day1 != day2 && i++ < 3);
  69
  70         spi_release_bus(slave);
  71
  72         tim = day1 * 86400 + time;
  73         to_tm(tim, rtc);
  74
  75         rtc->tm_yday = 0;
  76         rtc->tm_isdst = 0;
  77
  78         return 0;
  79 }
  80
  81 int rtc_set(struct rtc_time *rtc)
  82 {
  83         u32 time, day, reg;
  84
  85         if (!slave) {
  86                 /* FIXME: Verify the max SCK rate */
  87                 slave = spi_setup_slave(CONFIG_MC13783_SPI_BUS,
  88                                 CONFIG_MC13783_SPI_CS, 1000000,
  89                                 SPI_MODE_2 | SPI_CS_HIGH);
  90                 if (!slave)
  91                         return -1;
  92         }
  93
  94         time = mktime(rtc->tm_year, rtc->tm_mon, rtc->tm_mday,
  95                       rtc->tm_hour, rtc->tm_min, rtc->tm_sec);
  96         day = time / 86400;
  97         time %= 86400;
  98
  99         if (spi_claim_bus(slave))
 100                 return -1;
 101
 102         reg = 0x2c000000 | day | 0x80000000;
 103         spi_xfer(slave, 32, (uchar *)&reg, (uchar *)&day,
 104                         SPI_XFER_BEGIN | SPI_XFER_END);
 105
 106         reg = 0x28000000 | time | 0x80000000;
 107         spi_xfer(slave, 32, (uchar *)&reg, (uchar *)&time,
 108                         SPI_XFER_BEGIN | SPI_XFER_END);
 109
 110         spi_release_bus(slave);
 111
 112         return 0;
 113 }
 114
 115 void rtc_reset(void)
 116 {
 117 }