drivers/rtc/s3c24x0_rtc.c

   1 /*
   2  * (C) Copyright 2003
   3  * David Müller ELSOFT AG Switzerland. d.mueller@elsoft.ch
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * Date & Time support for the built-in Samsung S3C24X0 RTC
  10  */
  11
  12 #include <common.h>
  13 #include <command.h>
  14
  15 #if (defined(CONFIG_CMD_DATE))
  16
  17 #include <asm/arch/s3c24x0_cpu.h>
  18
  19 #include <rtc.h>
  20 #include <asm/io.h>
  21 #include <linux/compiler.h>
  22
  23 typedef enum {
  24         RTC_ENABLE,
  25         RTC_DISABLE
  26 } RTC_ACCESS;
  27
  28
  29 static inline void SetRTC_Access(RTC_ACCESS a)
  30 {
  31         struct s3c24x0_rtc *rtc = s3c24x0_get_base_rtc();
  32
  33         switch (a) {
  34         case RTC_ENABLE:
  35                 writeb(readb(&rtc->rtccon) | 0x01, &rtc->rtccon);
  36                 break;
  37
  38         case RTC_DISABLE:
  39                 writeb(readb(&rtc->rtccon) & ~0x01, &rtc->rtccon);
  40                 break;
  41         }
  42 }
  43
  44 /* ------------------------------------------------------------------------- */
  45
  46 int rtc_get(struct rtc_time *tmp)
  47 {
  48         struct s3c24x0_rtc *rtc = s3c24x0_get_base_rtc();
  49         uchar sec, min, hour, mday, wday, mon, year;
  50         __maybe_unused uchar a_sec, a_min, a_hour, a_date,
  51                              a_mon, a_year, a_armed;
  52
  53         /* enable access to RTC registers */
  54         SetRTC_Access(RTC_ENABLE);
  55
  56         /* read RTC registers */
  57         do {
  58                 sec  = readb(&rtc->bcdsec);
  59                 min  = readb(&rtc->bcdmin);
  60                 hour = readb(&rtc->bcdhour);
  61                 mday = readb(&rtc->bcddate);
  62                 wday = readb(&rtc->bcdday);
  63                 mon  = readb(&rtc->bcdmon);
  64                 year = readb(&rtc->bcdyear);
  65         } while (sec != readb(&rtc->bcdsec));
  66
  67         /* read ALARM registers */
  68         a_sec   = readb(&rtc->almsec);
  69         a_min   = readb(&rtc->almmin);
  70         a_hour  = readb(&rtc->almhour);
  71         a_date  = readb(&rtc->almdate);
  72         a_mon   = readb(&rtc->almmon);
  73         a_year  = readb(&rtc->almyear);
  74         a_armed = readb(&rtc->rtcalm);
  75
  76         /* disable access to RTC registers */
  77         SetRTC_Access(RTC_DISABLE);
  78
  79 #ifdef RTC_DEBUG
  80         printf("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
  81                "hr: %02x min: %02x sec: %02x\n",
  82                year, mon, mday, wday, hour, min, sec);
  83         printf("Alarms: %02x: year: %02x month: %02x date: %02x hour: "
  84                "%02x min: %02x sec: %02x\n",
  85                a_armed, a_year, a_mon, a_date, a_hour, a_min, a_sec);
  86 #endif
  87
  88         tmp->tm_sec  = bcd2bin(sec & 0x7F);
  89         tmp->tm_min  = bcd2bin(min & 0x7F);
  90         tmp->tm_hour = bcd2bin(hour & 0x3F);
  91         tmp->tm_mday = bcd2bin(mday & 0x3F);
  92         tmp->tm_mon  = bcd2bin(mon & 0x1F);
  93         tmp->tm_year = bcd2bin(year);
  94         tmp->tm_wday = bcd2bin(wday & 0x07);
  95         if (tmp->tm_year < 70)
  96                 tmp->tm_year += 2000;
  97         else
  98                 tmp->tm_year += 1900;
  99         tmp->tm_yday  = 0;
 100         tmp->tm_isdst = 0;
 101 #ifdef RTC_DEBUG
 102         printf("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 103                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 104                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 105 #endif
 106
 107         return 0;
 108 }
 109
 110 int rtc_set(struct rtc_time *tmp)
 111 {
 112         struct s3c24x0_rtc *rtc = s3c24x0_get_base_rtc();
 113         uchar sec, min, hour, mday, wday, mon, year;
 114
 115 #ifdef RTC_DEBUG
 116         printf("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 117                tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
 118                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
 119 #endif
 120         year = bin2bcd(tmp->tm_year % 100);
 121         mon  = bin2bcd(tmp->tm_mon);
 122         wday = bin2bcd(tmp->tm_wday);
 123         mday = bin2bcd(tmp->tm_mday);
 124         hour = bin2bcd(tmp->tm_hour);
 125         min  = bin2bcd(tmp->tm_min);
 126         sec  = bin2bcd(tmp->tm_sec);
 127
 128         /* enable access to RTC registers */
 129         SetRTC_Access(RTC_ENABLE);
 130
 131         /* write RTC registers */
 132         writeb(sec, &rtc->bcdsec);
 133         writeb(min, &rtc->bcdmin);
 134         writeb(hour, &rtc->bcdhour);
 135         writeb(mday, &rtc->bcddate);
 136         writeb(wday, &rtc->bcdday);
 137         writeb(mon, &rtc->bcdmon);
 138         writeb(year, &rtc->bcdyear);
 139
 140         /* disable access to RTC registers */
 141         SetRTC_Access(RTC_DISABLE);
 142
 143         return 0;
 144 }
 145
 146 void rtc_reset(void)
 147 {
 148         struct s3c24x0_rtc *rtc = s3c24x0_get_base_rtc();
 149
 150         writeb((readb(&rtc->rtccon) & ~0x06) | 0x08, &rtc->rtccon);
 151         writeb(readb(&rtc->rtccon) & ~(0x08 | 0x01), &rtc->rtccon);
 152 }
 153
 154 #endif