drivers/rtc/pcf2127.c

   1 /*
   2  * Copyright (C) 2016 by NXP Semiconductors Inc.
   3  * Date & Time support for PCF2127 RTC
   4  */
   5
   6 /*      #define DEBUG   */
   7
   8 #include <common.h>
   9 #include <command.h>
  10 #include <dm.h>
  11 #include <i2c.h>
  12 #include <rtc.h>
  13
  14 #define PCF2127_REG_CTRL1       0x00
  15 #define PCF2127_REG_CTRL2       0x01
  16 #define PCF2127_REG_CTRL3       0x02
  17 #define PCF2127_REG_SC          0x03
  18 #define PCF2127_REG_MN          0x04
  19 #define PCF2127_REG_HR          0x05
  20 #define PCF2127_REG_DM          0x06
  21 #define PCF2127_REG_DW          0x07
  22 #define PCF2127_REG_MO          0x08
  23 #define PCF2127_REG_YR          0x09
  24
  25 static int pcf2127_rtc_set(struct udevice *dev, const struct rtc_time *tm)
  26 {
  27         uchar buf[8];
  28         int i = 0, ret;
  29
  30         /* start register address */
  31         buf[i++] = PCF2127_REG_SC;
  32
  33         /* hours, minutes and seconds */
  34         buf[i++] = bin2bcd(tm->tm_sec);
  35         buf[i++] = bin2bcd(tm->tm_min);
  36         buf[i++] = bin2bcd(tm->tm_hour);
  37         buf[i++] = bin2bcd(tm->tm_mday);
  38         buf[i++] = tm->tm_wday & 0x07;
  39
  40         /* month, 1 - 12 */
  41         buf[i++] = bin2bcd(tm->tm_mon + 1);
  42
  43         /* year */
  44         buf[i++] = bin2bcd(tm->tm_year % 100);
  45
  46         /* write register's data */
  47         ret = dm_i2c_write(dev, PCF2127_REG_CTRL1, buf, sizeof(buf));
  48
  49         return ret;
  50 }
  51
  52 static int pcf2127_rtc_get(struct udevice *dev, struct rtc_time *tm)
  53 {
  54         int ret = 0;
  55         uchar buf[10] = { PCF2127_REG_CTRL1 };
  56
  57         ret = dm_i2c_write(dev, PCF2127_REG_CTRL1, buf, 1);
  58         if (ret < 0)
  59                 return ret;
  60         ret = dm_i2c_read(dev, PCF2127_REG_CTRL1, buf, sizeof(buf));
  61         if (ret < 0)
  62                 return ret;
  63
  64         if (buf[PCF2127_REG_CTRL3] & 0x04)
  65                 puts("### Warning: RTC Low Voltage - date/time not reliable\n");
  66
  67         tm->tm_sec  = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
  68         tm->tm_min  = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
  69         tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F);
  70         tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
  71         tm->tm_mon  = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1;
  72         tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]) + 1900;
  73         if (tm->tm_year < 1970)
  74                 tm->tm_year += 100;     /* assume we are in 1970...2069 */
  75         tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
  76         tm->tm_yday = 0;
  77         tm->tm_isdst = 0;
  78
  79         debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
  80               tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
  81               tm->tm_hour, tm->tm_min, tm->tm_sec);
  82
  83         return ret;
  84 }
  85
  86 static int pcf2127_rtc_reset(struct udevice *dev)
  87 {
  88         /*Doing nothing here*/
  89
  90         return 0;
  91 }
  92
  93 static const struct rtc_ops pcf2127_rtc_ops = {
  94         .get = pcf2127_rtc_get,
  95         .set = pcf2127_rtc_set,
  96         .reset = pcf2127_rtc_reset,
  97 };
  98
  99 static const struct udevice_id pcf2127_rtc_ids[] = {
 100         { .compatible = "pcf2127-rtc" },
 101         { }
 102 };
 103
 104 U_BOOT_DRIVER(rtc_pcf2127) = {
 105         .name   = "rtc-pcf2127",
 106         .id     = UCLASS_RTC,
 107         .of_match = pcf2127_rtc_ids,
 108         .ops    = &pcf2127_rtc_ops,
 109 };