blob: 73919cd98d0ca3aee0dd8fbd116520ba1e803911 [file] [log] [blame]
wdenk4c0d4c32004-06-09 17:34:58 +00001/*
2 * (C) Copyright 2004
3 * Wolfgang Denk, DENX Software Engineering, wd@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 for MAXIM MAX6900 RTC
26 */
27
28/* #define DEBUG */
29
30#include <common.h>
31#include <command.h>
32#include <rtc.h>
33#include <i2c.h>
34
35#if defined(CONFIG_RTC_MAX6900) && (CONFIG_COMMANDS & CFG_CMD_DATE)
36
37#ifndef CFG_I2C_RTC_ADDR
38#define CFG_I2C_RTC_ADDR 0x50
39#endif
40
41/* ------------------------------------------------------------------------- */
42
43static uchar rtc_read (uchar reg)
44{
45 return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg));
46}
47
48static void rtc_write (uchar reg, uchar val)
49{
50 i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);
51 udelay(2500);
52}
53
54static unsigned bcd2bin (uchar n)
55{
56 return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
57}
58
59static unsigned char bin2bcd (unsigned int n)
60{
61 return (((n / 10) << 4) | (n % 10));
62}
63
64/* ------------------------------------------------------------------------- */
65
66void rtc_get (struct rtc_time *tmp)
67{
68 uchar sec, min, hour, mday, wday, mon, cent, year;
69 int retry = 1;
70
71 do {
72 sec = rtc_read (0x80);
73 min = rtc_read (0x82);
74 hour = rtc_read (0x84);
75 mday = rtc_read (0x86);
76 mon = rtc_read (0x88);
77 wday = rtc_read (0x8a);
78 year = rtc_read (0x8c);
79 cent = rtc_read (0x92);
80 /*
81 * Check for seconds rollover
82 */
83 if ((sec != 59) || (rtc_read(0x80) == sec)){
84 retry = 0;
85 }
86 } while (retry);
87
88 debug ( "Get RTC year: %02x mon: %02x cent: %02x mday: %02x wday: %02x "
89 "hr: %02x min: %02x sec: %02x\n",
90 year, mon, cent, mday, wday,
91 hour, min, sec );
92
93 tmp->tm_sec = bcd2bin (sec & 0x7F);
94 tmp->tm_min = bcd2bin (min & 0x7F);
95 tmp->tm_hour = bcd2bin (hour & 0x3F);
96 tmp->tm_mday = bcd2bin (mday & 0x3F);
97 tmp->tm_mon = bcd2bin (mon & 0x1F);
98 tmp->tm_year = bcd2bin (year) + bcd2bin(cent) * 100;
99 tmp->tm_wday = bcd2bin (wday & 0x07);
100 tmp->tm_yday = 0;
101 tmp->tm_isdst= 0;
102
103 debug ( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
104 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
105 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
106}
107
108void rtc_set (struct rtc_time *tmp)
109{
110
111 debug ( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
112 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
113 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
114
115 rtc_write (0x9E, 0x00);
116 rtc_write (0x80, 0); /* Clear seconds to ensure no rollover */
117 rtc_write (0x92, bin2bcd(tmp->tm_year / 100));
118 rtc_write (0x8c, bin2bcd(tmp->tm_year % 100));
119 rtc_write (0x8a, bin2bcd(tmp->tm_wday));
120 rtc_write (0x88, bin2bcd(tmp->tm_mon));
121 rtc_write (0x86, bin2bcd(tmp->tm_mday));
122 rtc_write (0x84, bin2bcd(tmp->tm_hour));
123 rtc_write (0x82, bin2bcd(tmp->tm_min ));
124 rtc_write (0x80, bin2bcd(tmp->tm_sec ));
125}
126
127void rtc_reset (void)
128{
129}
130
131#endif /* CONFIG_RTC_MAX6900 && CFG_CMD_DATE */