LXR uboot/drivers/rtc/m48t35ax.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright 2001
   4 * Erik Theisen,  Wave 7 Optics, etheisen@mindspring.com.
   5 */
   6
   7/*
   8 * Date & Time support for ST Electronics M48T35Ax RTC
   9 */
  10
  11/*#define       DEBUG */
  12
  13
  14#include <common.h>
  15#include <command.h>
  16#include <rtc.h>
  17#include <config.h>
  18
  19static uchar rtc_read  (uchar reg);
  20static void  rtc_write (uchar reg, uchar val);
  21
  22/* ------------------------------------------------------------------------- */
  23
  24int rtc_get (struct rtc_time *tmp)
  25{
  26        uchar sec, min, hour, cent_day, date, month, year;
  27        uchar ccr;                      /* Clock control register */
  28
  29        /* Lock RTC for read using clock control register */
  30        ccr = rtc_read(0);
  31        ccr = ccr | 0x40;
  32        rtc_write(0, ccr);
  33
  34        sec     = rtc_read (0x1);
  35        min     = rtc_read (0x2);
  36        hour    = rtc_read (0x3);
  37        cent_day= rtc_read (0x4);
  38        date    = rtc_read (0x5);
  39        month   = rtc_read (0x6);
  40        year    = rtc_read (0x7);
  41
  42        /* UNLock RTC */
  43        ccr = rtc_read(0);
  44        ccr = ccr & 0xBF;
  45        rtc_write(0, ccr);
  46
  47        debug ( "Get RTC year: %02x month: %02x date: %02x cent_day: %02x "
  48                "hr: %02x min: %02x sec: %02x\n",
  49                year, month, date, cent_day,
  50                hour, min, sec );
  51
  52        tmp->tm_sec  = bcd2bin (sec  & 0x7F);
  53        tmp->tm_min  = bcd2bin (min  & 0x7F);
  54        tmp->tm_hour = bcd2bin (hour & 0x3F);
  55        tmp->tm_mday = bcd2bin (date & 0x3F);
  56        tmp->tm_mon  = bcd2bin (month & 0x1F);
  57        tmp->tm_year = bcd2bin (year) + ((cent_day & 0x10) ? 2000 : 1900);
  58        tmp->tm_wday = bcd2bin (cent_day & 0x07);
  59        tmp->tm_yday = 0;
  60        tmp->tm_isdst= 0;
  61
  62        debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  63                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  64                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  65
  66        return 0;
  67}
  68
  69int rtc_set (struct rtc_time *tmp)
  70{
  71        uchar ccr;                      /* Clock control register */
  72        uchar century;
  73
  74        debug ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  75                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  76                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  77
  78        /* Lock RTC for write using clock control register */
  79        ccr = rtc_read(0);
  80        ccr = ccr | 0x80;
  81        rtc_write(0, ccr);
  82
  83        rtc_write (0x07, bin2bcd(tmp->tm_year % 100));
  84        rtc_write (0x06, bin2bcd(tmp->tm_mon));
  85        rtc_write (0x05, bin2bcd(tmp->tm_mday));
  86
  87        century = ((tmp->tm_year >= 2000) ? 0x10 : 0) | 0x20;
  88        rtc_write (0x04, bin2bcd(tmp->tm_wday) | century);
  89
  90        rtc_write (0x03, bin2bcd(tmp->tm_hour));
  91        rtc_write (0x02, bin2bcd(tmp->tm_min ));
  92        rtc_write (0x01, bin2bcd(tmp->tm_sec ));
  93
  94        /* UNLock RTC */
  95        ccr = rtc_read(0);
  96        ccr = ccr & 0x7F;
  97        rtc_write(0, ccr);
  98
  99        return 0;
 100}
 101
 102void rtc_reset (void)
 103{
 104        uchar val;
 105
 106        /* Clear all clock control registers */
 107        rtc_write (0x0, 0x80);          /* No Read Lock or calibration */
 108
 109        /* Clear stop bit */
 110        val = rtc_read (0x1);
 111        val &= 0x7f;
 112        rtc_write(0x1, val);
 113
 114        /* Enable century / disable frequency test */
 115        val = rtc_read (0x4);
 116        val = (val & 0xBF) | 0x20;
 117        rtc_write(0x4, val);
 118
 119        /* Clear write lock */
 120        rtc_write(0x0, 0);
 121}
 122
 123/* ------------------------------------------------------------------------- */
 124
 125static uchar rtc_read (uchar reg)
 126{
 127        return *(unsigned char *)
 128                ((CONFIG_SYS_NVRAM_BASE_ADDR + CONFIG_SYS_NVRAM_SIZE - 8) + reg);
 129}
 130
 131static void rtc_write (uchar reg, uchar val)
 132{
 133        *(unsigned char *)
 134                ((CONFIG_SYS_NVRAM_BASE_ADDR + CONFIG_SYS_NVRAM_SIZE - 8) + reg) = val;
 135}
 136