blob: 95cb18634808872da88720506510726ea78fa72e [file] [log] [blame]
Markus Klotzbuecher0be62722007-01-09 14:57:12 +01001/*
2 * (C) Copyright 2006
3 * Markus Klotzbuecher, mk@denx.de
4 *
5 * See file CREDITS for list of people who contributed to this
6 * project.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21 * MA 02111-1307 USA
22 */
23
24/*
25 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
26 * Extremly Accurate DS3231 Real Time Clock (RTC).
27 *
28 * copied from ds1337.c
29 */
30
31#include <common.h>
32#include <command.h>
33#include <rtc.h>
34#include <i2c.h>
35
Jon Loeligera5938142007-07-09 18:10:50 -050036#if defined(CONFIG_RTC_DS3231) && defined(CONFIG_CMD_DATE)
Markus Klotzbuecher0be62722007-01-09 14:57:12 +010037
38/*---------------------------------------------------------------------*/
39#undef DEBUG_RTC
40
41#ifdef DEBUG_RTC
42#define DEBUGR(fmt,args...) printf(fmt ,##args)
43#else
44#define DEBUGR(fmt,args...)
45#endif
46/*---------------------------------------------------------------------*/
47
48/*
49 * RTC register addresses
50 */
51#define RTC_SEC_REG_ADDR 0x0
52#define RTC_MIN_REG_ADDR 0x1
53#define RTC_HR_REG_ADDR 0x2
54#define RTC_DAY_REG_ADDR 0x3
55#define RTC_DATE_REG_ADDR 0x4
56#define RTC_MON_REG_ADDR 0x5
57#define RTC_YR_REG_ADDR 0x6
58#define RTC_CTL_REG_ADDR 0x0e
59#define RTC_STAT_REG_ADDR 0x0f
60
61
62/*
63 * RTC control register bits
64 */
65#define RTC_CTL_BIT_A1IE 0x1 /* Alarm 1 interrupt enable */
66#define RTC_CTL_BIT_A2IE 0x2 /* Alarm 2 interrupt enable */
67#define RTC_CTL_BIT_INTCN 0x4 /* Interrupt control */
68#define RTC_CTL_BIT_RS1 0x8 /* Rate select 1 */
69#define RTC_CTL_BIT_RS2 0x10 /* Rate select 2 */
70#define RTC_CTL_BIT_DOSC 0x80 /* Disable Oscillator */
71
72/*
73 * RTC status register bits
74 */
75#define RTC_STAT_BIT_A1F 0x1 /* Alarm 1 flag */
76#define RTC_STAT_BIT_A2F 0x2 /* Alarm 2 flag */
77#define RTC_STAT_BIT_OSF 0x80 /* Oscillator stop flag */
78
79
80static uchar rtc_read (uchar reg);
81static void rtc_write (uchar reg, uchar val);
82static uchar bin2bcd (unsigned int n);
83static unsigned bcd2bin (uchar c);
84
85
86/*
87 * Get the current time from the RTC
88 */
Yuri Tikhonovb73a19e2008-03-20 17:56:04 +030089int rtc_get (struct rtc_time *tmp)
Markus Klotzbuecher0be62722007-01-09 14:57:12 +010090{
Yuri Tikhonovb73a19e2008-03-20 17:56:04 +030091 int rel = 0;
Markus Klotzbuecher0be62722007-01-09 14:57:12 +010092 uchar sec, min, hour, mday, wday, mon_cent, year, control, status;
93
94 control = rtc_read (RTC_CTL_REG_ADDR);
95 status = rtc_read (RTC_STAT_REG_ADDR);
96 sec = rtc_read (RTC_SEC_REG_ADDR);
97 min = rtc_read (RTC_MIN_REG_ADDR);
98 hour = rtc_read (RTC_HR_REG_ADDR);
99 wday = rtc_read (RTC_DAY_REG_ADDR);
100 mday = rtc_read (RTC_DATE_REG_ADDR);
101 mon_cent = rtc_read (RTC_MON_REG_ADDR);
102 year = rtc_read (RTC_YR_REG_ADDR);
103
104 DEBUGR ("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
105 "hr: %02x min: %02x sec: %02x control: %02x status: %02x\n",
106 year, mon_cent, mday, wday, hour, min, sec, control, status);
107
108 if (status & RTC_STAT_BIT_OSF) {
109 printf ("### Warning: RTC oscillator has stopped\n");
110 /* clear the OSF flag */
111 rtc_write (RTC_STAT_REG_ADDR,
112 rtc_read (RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_OSF);
Yuri Tikhonovb73a19e2008-03-20 17:56:04 +0300113 rel = -1;
Markus Klotzbuecher0be62722007-01-09 14:57:12 +0100114 }
115
116 tmp->tm_sec = bcd2bin (sec & 0x7F);
117 tmp->tm_min = bcd2bin (min & 0x7F);
118 tmp->tm_hour = bcd2bin (hour & 0x3F);
119 tmp->tm_mday = bcd2bin (mday & 0x3F);
120 tmp->tm_mon = bcd2bin (mon_cent & 0x1F);
121 tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);
122 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
123 tmp->tm_yday = 0;
124 tmp->tm_isdst= 0;
125
126 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
127 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
128 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
Yuri Tikhonovb73a19e2008-03-20 17:56:04 +0300129
130 return rel;
Markus Klotzbuecher0be62722007-01-09 14:57:12 +0100131}
132
133
134/*
135 * Set the RTC
136 */
137void rtc_set (struct rtc_time *tmp)
138{
139 uchar century;
140
141 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
142 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
143 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
144
145 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
146
147 century = (tmp->tm_year >= 2000) ? 0x80 : 0;
148 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon) | century);
149
150 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
151 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
152 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
153 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
154 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
155}
156
157
158/*
159 * Reset the RTC. We also enable the oscillator output on the
160 * SQW/INTB* pin and program it for 32,768 Hz output. Note that
161 * according to the datasheet, turning on the square wave output
162 * increases the current drain on the backup battery from about
163 * 600 nA to 2uA.
164 */
165void rtc_reset (void)
166{
167 rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2);
168}
169
170
171/*
172 * Helper functions
173 */
174
175static
176uchar rtc_read (uchar reg)
177{
178 return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg));
179}
180
181
182static void rtc_write (uchar reg, uchar val)
183{
184 i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);
185}
186
187static unsigned bcd2bin (uchar n)
188{
189 return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
190}
191
192static unsigned char bin2bcd (unsigned int n)
193{
194 return (((n / 10) << 4) | (n % 10));
195}
196
Jon Loeligera5938142007-07-09 18:10:50 -0500197#endif