LXR uboot/drivers/rtc/rtc4543.c

   1/*
   2 * (C) Copyright 2008, 2009
   3 * Andreas Pfefferle, DENX Software Engineering, ap@denx.de.
   4 *
   5 * SPDX-License-Identifier:     GPL-2.0+
   6 */
   7
   8#include <asm/io.h>
   9#include <common.h>
  10#include <command.h>
  11#include <config.h>
  12#include <rtc.h>
  13#include <tws.h>
  14
  15#if defined(CONFIG_CMD_DATE)
  16
  17/*
  18 * Note: The acrobatics below is due to the hideously ingenius idea of
  19 * the chip designers.  As the chip does not allow register
  20 * addressing, all values need to be read and written in one go.  Sure
  21 * enough, the 'wday' field (0-6) is transferred using the economic
  22 * number of 4 bits right in the middle of the packet.....
  23 */
  24
  25int rtc_get(struct rtc_time *tm)
  26{
  27        int rel = 0;
  28        uchar buffer[7];
  29
  30        memset(buffer, 0, 7);
  31
  32        /* Read 52 bits into our buffer */
  33        tws_read(buffer, 52);
  34
  35        tm->tm_sec  = bcd2bin( buffer[0] & 0x7F);
  36        tm->tm_min  = bcd2bin( buffer[1] & 0x7F);
  37        tm->tm_hour = bcd2bin( buffer[2] & 0x3F);
  38        tm->tm_wday = bcd2bin( buffer[3] & 0x07);
  39        tm->tm_mday = bcd2bin((buffer[3] & 0xF0) >> 4 | (buffer[4] & 0x0F) << 4);
  40        tm->tm_mon  = bcd2bin((buffer[4] & 0x30) >> 4 | (buffer[5] & 0x0F) << 4);
  41        tm->tm_year = bcd2bin((buffer[5] & 0xF0) >> 4 | (buffer[6] & 0x0F) << 4) + 2000;
  42        tm->tm_yday = 0;
  43        tm->tm_isdst = 0;
  44
  45        if (tm->tm_sec & 0x80) {
  46                puts("### Warning: RTC Low Voltage - date/time not reliable\n");
  47                rel = -1;
  48        }
  49
  50        debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  51                tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
  52                tm->tm_hour, tm->tm_min, tm->tm_sec);
  53
  54        return rel;
  55}
  56
  57int rtc_set(struct rtc_time *tm)
  58{
  59        uchar buffer[7];
  60        uchar tmp;
  61
  62        debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  63                tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
  64                tm->tm_hour, tm->tm_min, tm->tm_sec);
  65
  66        memset(buffer, 0, 7);
  67        buffer[0] = bin2bcd(tm->tm_sec);
  68        buffer[1] = bin2bcd(tm->tm_min);
  69        buffer[2] = bin2bcd(tm->tm_hour);
  70        buffer[3] = bin2bcd(tm->tm_wday);
  71        tmp = bin2bcd(tm->tm_mday);
  72        buffer[3] |= (tmp & 0x0F) << 4;
  73        buffer[4] =  (tmp & 0xF0) >> 4;
  74        tmp = bin2bcd(tm->tm_mon);
  75        buffer[4] |= (tmp & 0x0F) << 4;
  76        buffer[5] =  (tmp & 0xF0) >> 4;
  77        tmp = bin2bcd(tm->tm_year  % 100);
  78        buffer[5] |= (tmp & 0x0F) << 4;
  79        buffer[6] =  (tmp & 0xF0) >> 4;
  80
  81        /* Write the resulting 52 bits to device */
  82        tws_write(buffer, 52);
  83
  84        return 0;
  85}
  86
  87void rtc_reset(void)
  88{
  89        struct rtc_time tmp;
  90
  91        tmp.tm_sec = 0;
  92        tmp.tm_min = 0;
  93        tmp.tm_hour = 0;
  94        tmp.tm_wday = 4;
  95        tmp.tm_mday = 1;
  96        tmp.tm_mon = 1;
  97        tmp.tm_year = 2000;
  98        rtc_set(&tmp);
  99}
 100
 101#endif
 102