3 * Tor Krill, Excito Elektronik i Skåne , tor@excito.com
5 * Modelled after the ds1337 driver
7 * SPDX-License-Identifier: GPL-2.0+
11 * Date & Time support (no alarms) for Intersil
12 * ISL1208 Real Time Clock (RTC).
20 /*---------------------------------------------------------------------*/
22 #define DEBUGR(fmt,args...) printf(fmt ,##args)
24 #define DEBUGR(fmt,args...)
26 /*---------------------------------------------------------------------*/
29 * RTC register addresses
32 #define RTC_SEC_REG_ADDR 0x0
33 #define RTC_MIN_REG_ADDR 0x1
34 #define RTC_HR_REG_ADDR 0x2
35 #define RTC_DATE_REG_ADDR 0x3
36 #define RTC_MON_REG_ADDR 0x4
37 #define RTC_YR_REG_ADDR 0x5
38 #define RTC_DAY_REG_ADDR 0x6
39 #define RTC_STAT_REG_ADDR 0x7
41 * RTC control register bits
45 * RTC status register bits
47 #define RTC_STAT_BIT_ARST 0x80 /* AUTO RESET ENABLE BIT */
48 #define RTC_STAT_BIT_XTOSCB 0x40 /* CRYSTAL OSCILLATOR ENABLE BIT */
49 #define RTC_STAT_BIT_WRTC 0x10 /* WRITE RTC ENABLE BIT */
50 #define RTC_STAT_BIT_ALM 0x04 /* ALARM BIT */
51 #define RTC_STAT_BIT_BAT 0x02 /* BATTERY BIT */
52 #define RTC_STAT_BIT_RTCF 0x01 /* REAL TIME CLOCK FAIL BIT */
54 static uchar rtc_read (uchar reg);
55 static void rtc_write (uchar reg, uchar val);
58 * Get the current time from the RTC
61 int rtc_get (struct rtc_time *tmp)
64 uchar sec, min, hour, mday, wday, mon, year, status;
66 status = rtc_read (RTC_STAT_REG_ADDR);
67 sec = rtc_read (RTC_SEC_REG_ADDR);
68 min = rtc_read (RTC_MIN_REG_ADDR);
69 hour = rtc_read (RTC_HR_REG_ADDR);
70 wday = rtc_read (RTC_DAY_REG_ADDR);
71 mday = rtc_read (RTC_DATE_REG_ADDR);
72 mon = rtc_read (RTC_MON_REG_ADDR);
73 year = rtc_read (RTC_YR_REG_ADDR);
75 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
76 "hr: %02x min: %02x sec: %02x status: %02x\n",
77 year, mon, mday, wday, hour, min, sec, status);
79 if (status & RTC_STAT_BIT_RTCF) {
80 printf ("### Warning: RTC oscillator has stopped\n");
81 rtc_write(RTC_STAT_REG_ADDR,
82 rtc_read(RTC_STAT_REG_ADDR) &~ (RTC_STAT_BIT_BAT|RTC_STAT_BIT_RTCF));
86 tmp->tm_sec = bcd2bin (sec & 0x7F);
87 tmp->tm_min = bcd2bin (min & 0x7F);
88 tmp->tm_hour = bcd2bin (hour & 0x3F);
89 tmp->tm_mday = bcd2bin (mday & 0x3F);
90 tmp->tm_mon = bcd2bin (mon & 0x1F);
91 tmp->tm_year = bcd2bin (year)+2000;
92 tmp->tm_wday = bcd2bin (wday & 0x07);
96 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
97 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
98 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
106 int rtc_set (struct rtc_time *tmp)
108 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
109 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
110 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
113 rtc_write(RTC_STAT_REG_ADDR,
114 rtc_read(RTC_STAT_REG_ADDR) | RTC_STAT_BIT_WRTC);
116 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
117 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
118 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday));
119 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
120 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour) | 0x80 ); /* 24h clock */
121 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
122 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
125 rtc_write(RTC_STAT_REG_ADDR,
126 rtc_read(RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_WRTC);
131 void rtc_reset (void)
139 static uchar rtc_read (uchar reg)
141 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
144 static void rtc_write (uchar reg, uchar val)
146 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);