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wdenk1cb8e982003-03-06 21:55:29 +00001/*
2 * (C) Copyright 2001, 2002, 2003
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4 * Keith Outwater, keith_outwater@mvis.com`
5 * Steven Scholz, steven.scholz@imc-berlin.de
6 *
7 * See file CREDITS for list of people who contributed to this
8 * project.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of
13 * the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23 * MA 02111-1307 USA
24 */
25
26/*
27 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
wdenk7f70e852003-05-20 14:25:27 +000028 * DS1307 and DS1338 Real Time Clock (RTC).
wdenk1cb8e982003-03-06 21:55:29 +000029 *
30 * based on ds1337.c
31 */
32
33#include <common.h>
34#include <command.h>
35#include <rtc.h>
36#include <i2c.h>
37
wdenk7f70e852003-05-20 14:25:27 +000038#if (defined(CONFIG_RTC_DS1307) || defined(CONFIG_RTC_DS1338) ) && \
39 (CONFIG_COMMANDS & CFG_CMD_DATE)
wdenk1cb8e982003-03-06 21:55:29 +000040
41/*---------------------------------------------------------------------*/
42#undef DEBUG_RTC
43
44#ifdef DEBUG_RTC
45#define DEBUGR(fmt,args...) printf(fmt ,##args)
46#else
47#define DEBUGR(fmt,args...)
48#endif
49/*---------------------------------------------------------------------*/
50
51#ifndef CFG_I2C_RTC_ADDR
52# define CFG_I2C_RTC_ADDR 0x68
53#endif
54
wdenk3d3befa2004-03-14 15:06:13 +000055#if defined(CONFIG_RTC_DS1307) && (CFG_I2C_SPEED > 100000)
wdenk1cb8e982003-03-06 21:55:29 +000056# error The DS1307 is specified only up to 100kHz!
57#endif
58
59/*
60 * RTC register addresses
61 */
62#define RTC_SEC_REG_ADDR 0x00
63#define RTC_MIN_REG_ADDR 0x01
64#define RTC_HR_REG_ADDR 0x02
65#define RTC_DAY_REG_ADDR 0x03
66#define RTC_DATE_REG_ADDR 0x04
67#define RTC_MON_REG_ADDR 0x05
68#define RTC_YR_REG_ADDR 0x06
69#define RTC_CTL_REG_ADDR 0x07
70
71#define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */
72
73#define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */
74#define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */
75#define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */
76#define RTC_CTL_BIT_OUT 0x80 /* Output Control */
77
78static uchar rtc_read (uchar reg);
79static void rtc_write (uchar reg, uchar val);
80static uchar bin2bcd (unsigned int n);
81static unsigned bcd2bin (uchar c);
82
83/*
84 * Get the current time from the RTC
85 */
86void rtc_get (struct rtc_time *tmp)
87{
88 uchar sec, min, hour, mday, wday, mon, year;
89
90 sec = rtc_read (RTC_SEC_REG_ADDR);
91 min = rtc_read (RTC_MIN_REG_ADDR);
92 hour = rtc_read (RTC_HR_REG_ADDR);
93 wday = rtc_read (RTC_DAY_REG_ADDR);
94 mday = rtc_read (RTC_DATE_REG_ADDR);
95 mon = rtc_read (RTC_MON_REG_ADDR);
96 year = rtc_read (RTC_YR_REG_ADDR);
97
98 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
99 "hr: %02x min: %02x sec: %02x\n",
100 year, mon, mday, wday, hour, min, sec);
101
102 if (sec & RTC_SEC_BIT_CH) {
103 printf ("### Warning: RTC oscillator has stopped\n");
104 /* clear the CH flag */
105 rtc_write (RTC_SEC_REG_ADDR,
106 rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH);
107 }
wdenk8bde7f72003-06-27 21:31:46 +0000108
wdenk1cb8e982003-03-06 21:55:29 +0000109 tmp->tm_sec = bcd2bin (sec & 0x7F);
110 tmp->tm_min = bcd2bin (min & 0x7F);
111 tmp->tm_hour = bcd2bin (hour & 0x3F);
112 tmp->tm_mday = bcd2bin (mday & 0x3F);
113 tmp->tm_mon = bcd2bin (mon & 0x1F);
114 tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
115 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
116 tmp->tm_yday = 0;
117 tmp->tm_isdst= 0;
118
119 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
120 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
121 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
122}
123
124
125/*
126 * Set the RTC
127 */
128void rtc_set (struct rtc_time *tmp)
129{
130 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
131 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
132 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
133
134 if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
135 printf("WARNING: year should be between 1970 and 2069!\n");
wdenk8bde7f72003-06-27 21:31:46 +0000136
wdenk1cb8e982003-03-06 21:55:29 +0000137 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
138 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
139 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
140 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
141 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
142 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
143 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
144}
145
146
147/*
wdenk8bde7f72003-06-27 21:31:46 +0000148 * Reset the RTC. We setting the date back to 1970-01-01.
149 * We also enable the oscillator output on the SQW/OUT pin and program
wdenk1cb8e982003-03-06 21:55:29 +0000150 * it for 32,768 Hz output. Note that according to the datasheet, turning
151 * on the square wave output increases the current drain on the backup
152 * battery to something between 480nA and 800nA.
153 */
154void rtc_reset (void)
155{
156 struct rtc_time tmp;
157
158 rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */
159 rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0);
160
161 tmp.tm_year = 1970;
162 tmp.tm_mon = 1;
163 tmp.tm_mday= 1;
164 tmp.tm_hour = 0;
165 tmp.tm_min = 0;
166 tmp.tm_sec = 0;
167
168 rtc_set(&tmp);
169
170 printf ( "RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n",
171 tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
172 tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
173
174 return;
175}
176
177
178/*
179 * Helper functions
180 */
181
182static
183uchar rtc_read (uchar reg)
184{
185 return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg));
186}
187
188
189static void rtc_write (uchar reg, uchar val)
190{
191 i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);
192}
193
194static unsigned bcd2bin (uchar n)
195{
196 return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
197}
198
199static unsigned char bin2bcd (unsigned int n)
200{
201 return (((n / 10) << 4) | (n % 10));
202}
203
wdenk7f70e852003-05-20 14:25:27 +0000204#endif /* (CONFIG_RTC_DS1307 || CONFIG_RTC_DS1338) && (CFG_COMMANDS & CFG_CMD_DATE) */