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rename CFG_ macros to CONFIG_SYS
[people/ms/u-boot.git] / drivers / rtc / ds1307.c
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1/*
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)
7f70e853 28 * DS1307 and DS1338 Real Time Clock (RTC).
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29 *
30 * based on ds1337.c
31 */
32
33#include <common.h>
34#include <command.h>
35#include <rtc.h>
36#include <i2c.h>
37
871c18dd 38#if defined(CONFIG_CMD_DATE)
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39
40/*---------------------------------------------------------------------*/
41#undef DEBUG_RTC
42
43#ifdef DEBUG_RTC
44#define DEBUGR(fmt,args...) printf(fmt ,##args)
45#else
46#define DEBUGR(fmt,args...)
47#endif
48/*---------------------------------------------------------------------*/
49
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50#ifndef CONFIG_SYS_I2C_RTC_ADDR
51# define CONFIG_SYS_I2C_RTC_ADDR 0x68
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52#endif
53
6d0f6bcf 54#if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000)
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55# error The DS1307 is specified only up to 100kHz!
56#endif
57
58/*
59 * RTC register addresses
60 */
61#define RTC_SEC_REG_ADDR 0x00
62#define RTC_MIN_REG_ADDR 0x01
63#define RTC_HR_REG_ADDR 0x02
64#define RTC_DAY_REG_ADDR 0x03
65#define RTC_DATE_REG_ADDR 0x04
66#define RTC_MON_REG_ADDR 0x05
67#define RTC_YR_REG_ADDR 0x06
68#define RTC_CTL_REG_ADDR 0x07
69
70#define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */
71
72#define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */
73#define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */
74#define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */
75#define RTC_CTL_BIT_OUT 0x80 /* Output Control */
76
77static uchar rtc_read (uchar reg);
78static void rtc_write (uchar reg, uchar val);
79static uchar bin2bcd (unsigned int n);
80static unsigned bcd2bin (uchar c);
81
82/*
83 * Get the current time from the RTC
84 */
b73a19e1 85int rtc_get (struct rtc_time *tmp)
1cb8e980 86{
b73a19e1 87 int rel = 0;
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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);
b73a19e1 107 rel = -1;
1cb8e980 108 }
8bde7f77 109
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110 tmp->tm_sec = bcd2bin (sec & 0x7F);
111 tmp->tm_min = bcd2bin (min & 0x7F);
112 tmp->tm_hour = bcd2bin (hour & 0x3F);
113 tmp->tm_mday = bcd2bin (mday & 0x3F);
114 tmp->tm_mon = bcd2bin (mon & 0x1F);
115 tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
116 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
117 tmp->tm_yday = 0;
118 tmp->tm_isdst= 0;
119
120 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
121 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
122 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
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123
124 return rel;
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125}
126
127
128/*
129 * Set the RTC
130 */
d1e23194 131int rtc_set (struct rtc_time *tmp)
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132{
133 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
134 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
135 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
136
137 if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
138 printf("WARNING: year should be between 1970 and 2069!\n");
8bde7f77 139
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140 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
141 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
142 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
143 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
144 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
145 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
146 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
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147
148 return 0;
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149}
150
151
152/*
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153 * Reset the RTC. We setting the date back to 1970-01-01.
154 * We also enable the oscillator output on the SQW/OUT pin and program
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155 * it for 32,768 Hz output. Note that according to the datasheet, turning
156 * on the square wave output increases the current drain on the backup
157 * battery to something between 480nA and 800nA.
158 */
159void rtc_reset (void)
160{
161 struct rtc_time tmp;
162
163 rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */
164 rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0);
165
166 tmp.tm_year = 1970;
167 tmp.tm_mon = 1;
168 tmp.tm_mday= 1;
169 tmp.tm_hour = 0;
170 tmp.tm_min = 0;
171 tmp.tm_sec = 0;
172
173 rtc_set(&tmp);
174
175 printf ( "RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n",
176 tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
177 tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
178
179 return;
180}
181
182
183/*
184 * Helper functions
185 */
186
187static
188uchar rtc_read (uchar reg)
189{
6d0f6bcf 190 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
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191}
192
193
194static void rtc_write (uchar reg, uchar val)
195{
6d0f6bcf 196 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
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197}
198
199static unsigned bcd2bin (uchar n)
200{
201 return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
202}
203
204static unsigned char bin2bcd (unsigned int n)
205{
206 return (((n / 10) << 4) | (n % 10));
207}
208
068b60a0 209#endif