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Markus Klotzbuecher0be62722007-01-09 14:57:12 +01001/*
2 * (C) Copyright 2006
3 * Markus Klotzbuecher, mk@denx.de
4 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02005 * SPDX-License-Identifier: GPL-2.0+
Markus Klotzbuecher0be62722007-01-09 14:57:12 +01006 */
7
8/*
9 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
10 * Extremly Accurate DS3231 Real Time Clock (RTC).
11 *
12 * copied from ds1337.c
13 */
14
15#include <common.h>
16#include <command.h>
17#include <rtc.h>
18#include <i2c.h>
19
Michal Simek871c18d2008-07-14 19:45:37 +020020#if defined(CONFIG_CMD_DATE)
Markus Klotzbuecher0be62722007-01-09 14:57:12 +010021
Markus Klotzbuecher0be62722007-01-09 14:57:12 +010022/*
23 * RTC register addresses
24 */
25#define RTC_SEC_REG_ADDR 0x0
26#define RTC_MIN_REG_ADDR 0x1
27#define RTC_HR_REG_ADDR 0x2
28#define RTC_DAY_REG_ADDR 0x3
29#define RTC_DATE_REG_ADDR 0x4
30#define RTC_MON_REG_ADDR 0x5
31#define RTC_YR_REG_ADDR 0x6
32#define RTC_CTL_REG_ADDR 0x0e
33#define RTC_STAT_REG_ADDR 0x0f
34
35
36/*
37 * RTC control register bits
38 */
39#define RTC_CTL_BIT_A1IE 0x1 /* Alarm 1 interrupt enable */
40#define RTC_CTL_BIT_A2IE 0x2 /* Alarm 2 interrupt enable */
41#define RTC_CTL_BIT_INTCN 0x4 /* Interrupt control */
42#define RTC_CTL_BIT_RS1 0x8 /* Rate select 1 */
43#define RTC_CTL_BIT_RS2 0x10 /* Rate select 2 */
44#define RTC_CTL_BIT_DOSC 0x80 /* Disable Oscillator */
45
46/*
47 * RTC status register bits
48 */
49#define RTC_STAT_BIT_A1F 0x1 /* Alarm 1 flag */
50#define RTC_STAT_BIT_A2F 0x2 /* Alarm 2 flag */
51#define RTC_STAT_BIT_OSF 0x80 /* Oscillator stop flag */
Priyanka Jainc3409412015-06-29 15:39:23 +053052#define RTC_STAT_BIT_BB32KHZ 0x40 /* Battery backed 32KHz Output */
53#define RTC_STAT_BIT_EN32KHZ 0x8 /* Enable 32KHz Output */
Markus Klotzbuecher0be62722007-01-09 14:57:12 +010054
55
56static uchar rtc_read (uchar reg);
57static void rtc_write (uchar reg, uchar val);
Markus Klotzbuecher0be62722007-01-09 14:57:12 +010058
59
60/*
61 * Get the current time from the RTC
62 */
Yuri Tikhonovb73a19e2008-03-20 17:56:04 +030063int rtc_get (struct rtc_time *tmp)
Markus Klotzbuecher0be62722007-01-09 14:57:12 +010064{
Yuri Tikhonovb73a19e2008-03-20 17:56:04 +030065 int rel = 0;
Markus Klotzbuecher0be62722007-01-09 14:57:12 +010066 uchar sec, min, hour, mday, wday, mon_cent, year, control, status;
67
68 control = rtc_read (RTC_CTL_REG_ADDR);
69 status = rtc_read (RTC_STAT_REG_ADDR);
70 sec = rtc_read (RTC_SEC_REG_ADDR);
71 min = rtc_read (RTC_MIN_REG_ADDR);
72 hour = rtc_read (RTC_HR_REG_ADDR);
73 wday = rtc_read (RTC_DAY_REG_ADDR);
74 mday = rtc_read (RTC_DATE_REG_ADDR);
75 mon_cent = rtc_read (RTC_MON_REG_ADDR);
76 year = rtc_read (RTC_YR_REG_ADDR);
77
Wolfgang Denk397b40c2011-11-04 15:55:12 +000078 debug("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
Markus Klotzbuecher0be62722007-01-09 14:57:12 +010079 "hr: %02x min: %02x sec: %02x control: %02x status: %02x\n",
80 year, mon_cent, mday, wday, hour, min, sec, control, status);
81
82 if (status & RTC_STAT_BIT_OSF) {
83 printf ("### Warning: RTC oscillator has stopped\n");
84 /* clear the OSF flag */
85 rtc_write (RTC_STAT_REG_ADDR,
86 rtc_read (RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_OSF);
Yuri Tikhonovb73a19e2008-03-20 17:56:04 +030087 rel = -1;
Markus Klotzbuecher0be62722007-01-09 14:57:12 +010088 }
89
90 tmp->tm_sec = bcd2bin (sec & 0x7F);
91 tmp->tm_min = bcd2bin (min & 0x7F);
92 tmp->tm_hour = bcd2bin (hour & 0x3F);
93 tmp->tm_mday = bcd2bin (mday & 0x3F);
94 tmp->tm_mon = bcd2bin (mon_cent & 0x1F);
95 tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);
96 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
97 tmp->tm_yday = 0;
98 tmp->tm_isdst= 0;
99
Wolfgang Denk397b40c2011-11-04 15:55:12 +0000100 debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
Markus Klotzbuecher0be62722007-01-09 14:57:12 +0100101 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
102 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
Yuri Tikhonovb73a19e2008-03-20 17:56:04 +0300103
104 return rel;
Markus Klotzbuecher0be62722007-01-09 14:57:12 +0100105}
106
107
108/*
109 * Set the RTC
110 */
Jean-Christophe PLAGNIOL-VILLARDd1e23192008-09-01 23:06:23 +0200111int rtc_set (struct rtc_time *tmp)
Markus Klotzbuecher0be62722007-01-09 14:57:12 +0100112{
113 uchar century;
114
Wolfgang Denk397b40c2011-11-04 15:55:12 +0000115 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
Markus Klotzbuecher0be62722007-01-09 14:57:12 +0100116 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
117 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
118
119 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
120
121 century = (tmp->tm_year >= 2000) ? 0x80 : 0;
122 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon) | century);
123
124 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
125 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
126 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
127 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
128 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
Jean-Christophe PLAGNIOL-VILLARDd1e23192008-09-01 23:06:23 +0200129
130 return 0;
Markus Klotzbuecher0be62722007-01-09 14:57:12 +0100131}
132
133
134/*
135 * Reset the RTC. We also enable the oscillator output on the
136 * SQW/INTB* pin and program it for 32,768 Hz output. Note that
137 * according to the datasheet, turning on the square wave output
138 * increases the current drain on the backup battery from about
139 * 600 nA to 2uA.
140 */
141void rtc_reset (void)
142{
143 rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2);
144}
145
Priyanka Jainc3409412015-06-29 15:39:23 +0530146/*
147 * Enable 32KHz output
148 */
149void rtc_enable_32khz_output(void)
150{
151 rtc_write(RTC_STAT_REG_ADDR,
152 RTC_STAT_BIT_BB32KHZ | RTC_STAT_BIT_EN32KHZ);
153}
Markus Klotzbuecher0be62722007-01-09 14:57:12 +0100154
155/*
156 * Helper functions
157 */
158
159static
160uchar rtc_read (uchar reg)
161{
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200162 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
Markus Klotzbuecher0be62722007-01-09 14:57:12 +0100163}
164
165
166static void rtc_write (uchar reg, uchar val)
167{
Jean-Christophe PLAGNIOL-VILLARD6d0f6bc2008-10-16 15:01:15 +0200168 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
Markus Klotzbuecher0be62722007-01-09 14:57:12 +0100169}
170
Jon Loeligera5938142007-07-09 18:10:50 -0500171#endif