LXR uboot/drivers/rtc/max6900.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * (C) Copyright 2004
   4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   5 */
   6
   7/*
   8 * Date & Time support for MAXIM MAX6900 RTC
   9 */
  10
  11/* #define      DEBUG   */
  12
  13#include <common.h>
  14#include <command.h>
  15#include <rtc.h>
  16#include <i2c.h>
  17#include <linux/delay.h>
  18
  19#ifndef CONFIG_SYS_I2C_RTC_ADDR
  20#define CONFIG_SYS_I2C_RTC_ADDR 0x50
  21#endif
  22
  23/* ------------------------------------------------------------------------- */
  24
  25static uchar rtc_read (uchar reg)
  26{
  27        return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
  28}
  29
  30static void rtc_write (uchar reg, uchar val)
  31{
  32        i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
  33        udelay(2500);
  34}
  35
  36/* ------------------------------------------------------------------------- */
  37
  38int rtc_get (struct rtc_time *tmp)
  39{
  40        uchar sec, min, hour, mday, wday, mon, cent, year;
  41        int retry = 1;
  42
  43        do {
  44                sec     = rtc_read (0x80);
  45                min     = rtc_read (0x82);
  46                hour    = rtc_read (0x84);
  47                mday    = rtc_read (0x86);
  48                mon     = rtc_read (0x88);
  49                wday    = rtc_read (0x8a);
  50                year    = rtc_read (0x8c);
  51                cent    = rtc_read (0x92);
  52                /*
  53                 * Check for seconds rollover
  54                 */
  55                if ((sec != 59) || (rtc_read(0x80) == sec)){
  56                        retry = 0;
  57                }
  58        } while (retry);
  59
  60        debug ( "Get RTC year: %02x mon: %02x cent: %02x mday: %02x wday: %02x "
  61                "hr: %02x min: %02x sec: %02x\n",
  62                year, mon, cent, mday, wday,
  63                hour, min, sec );
  64
  65        tmp->tm_sec  = bcd2bin (sec  & 0x7F);
  66        tmp->tm_min  = bcd2bin (min  & 0x7F);
  67        tmp->tm_hour = bcd2bin (hour & 0x3F);
  68        tmp->tm_mday = bcd2bin (mday & 0x3F);
  69        tmp->tm_mon  = bcd2bin (mon & 0x1F);
  70        tmp->tm_year = bcd2bin (year) + bcd2bin(cent) * 100;
  71        tmp->tm_wday = bcd2bin (wday & 0x07);
  72        tmp->tm_yday = 0;
  73        tmp->tm_isdst= 0;
  74
  75        debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  76                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  77                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  78
  79        return 0;
  80}
  81
  82int rtc_set (struct rtc_time *tmp)
  83{
  84
  85        debug ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  86                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  87                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  88
  89        rtc_write (0x9E, 0x00);
  90        rtc_write (0x80, 0);    /* Clear seconds to ensure no rollover */
  91        rtc_write (0x92, bin2bcd(tmp->tm_year / 100));
  92        rtc_write (0x8c, bin2bcd(tmp->tm_year % 100));
  93        rtc_write (0x8a, bin2bcd(tmp->tm_wday));
  94        rtc_write (0x88, bin2bcd(tmp->tm_mon));
  95        rtc_write (0x86, bin2bcd(tmp->tm_mday));
  96        rtc_write (0x84, bin2bcd(tmp->tm_hour));
  97        rtc_write (0x82, bin2bcd(tmp->tm_min ));
  98        rtc_write (0x80, bin2bcd(tmp->tm_sec ));
  99
 100        return 0;
 101}
 102
 103void rtc_reset (void)
 104{
 105}
 106