src/drivers/ams/as3722rtc.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <commonlib/bsd/bcd.h>
   4 #include <device/i2c_simple.h>
   5 #include <rtc.h>
   6 #include <stdint.h>
   7
   8 enum AS3722_RTC_REG
   9 {
  10         AS3722_RTC_CONTROL = 0x60,
  11         AS3722_RTC_SECOND = 0x61,
  12         AS3722_RTC_MINUTE = 0x62,
  13         AS3722_RTC_HOUR = 0x63,
  14         AS3722_RTC_DAY = 0x64,
  15         AS3722_RTC_MONTH = 0x65,
  16         AS3722_RTC_YEAR = 0x66
  17 };
  18
  19 enum {
  20         AS3722_RTC_CONTROL_ON = 0x1 << 2
  21 };
  22
  23 static uint8_t as3722_read(enum AS3722_RTC_REG reg)
  24 {
  25         uint8_t val;
  26         i2c_readb(CONFIG_DRIVERS_AS3722_RTC_BUS,
  27                   CONFIG_DRIVERS_AS3722_RTC_ADDR, reg, &val);
  28         return val;
  29 }
  30
  31 static void as3722_write(enum AS3722_RTC_REG reg, uint8_t val)
  32 {
  33         i2c_writeb(CONFIG_DRIVERS_AS3722_RTC_BUS,
  34                    CONFIG_DRIVERS_AS3722_RTC_ADDR, reg, val);
  35 }
  36
  37 static void as3722rtc_init(void)
  38 {
  39         static int initialized;
  40         if (initialized)
  41                 return;
  42
  43         uint8_t control = as3722_read(AS3722_RTC_CONTROL);
  44         as3722_write(AS3722_RTC_CONTROL, control | AS3722_RTC_CONTROL_ON);
  45
  46         initialized = 1;
  47 }
  48
  49 int rtc_set(const struct rtc_time *time)
  50 {
  51         as3722rtc_init();
  52
  53         as3722_write(AS3722_RTC_SECOND, bin2bcd(time->sec));
  54         as3722_write(AS3722_RTC_MINUTE, bin2bcd(time->min));
  55         as3722_write(AS3722_RTC_HOUR, bin2bcd(time->hour));
  56         as3722_write(AS3722_RTC_DAY, bin2bcd(time->mday));
  57         as3722_write(AS3722_RTC_MONTH, bin2bcd(time->mon));
  58         as3722_write(AS3722_RTC_YEAR, bin2bcd(time->year));
  59         return 0;
  60 }
  61
  62 int rtc_get(struct rtc_time *time)
  63 {
  64         as3722rtc_init();
  65
  66         time->sec = bcd2bin(as3722_read(AS3722_RTC_SECOND) & 0x7f);
  67         time->min = bcd2bin(as3722_read(AS3722_RTC_MINUTE) & 0x7f);
  68         time->hour = bcd2bin(as3722_read(AS3722_RTC_HOUR) & 0x3f);
  69         time->mday = bcd2bin(as3722_read(AS3722_RTC_DAY) & 0x3f);
  70         time->mon = bcd2bin(as3722_read(AS3722_RTC_MONTH) & 0x1f);
  71         time->year = bcd2bin(as3722_read(AS3722_RTC_YEAR) & 0x7f);
  72         return 0;
  73 }