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[people/ms/u-boot.git] / drivers / rtc / max6900.c
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1/*
2 * (C) Copyright 2004
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4 *
1a459660 5 * SPDX-License-Identifier: GPL-2.0+
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6 */
7
8/*
9 * Date & Time support for MAXIM MAX6900 RTC
10 */
11
12/* #define DEBUG */
13
14#include <common.h>
15#include <command.h>
16#include <rtc.h>
17#include <i2c.h>
18
871c18dd 19#if defined(CONFIG_CMD_DATE)
4c0d4c3b 20
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21#ifndef CONFIG_SYS_I2C_RTC_ADDR
22#define CONFIG_SYS_I2C_RTC_ADDR 0x50
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23#endif
24
25/* ------------------------------------------------------------------------- */
26
27static uchar rtc_read (uchar reg)
28{
6d0f6bcf 29 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
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30}
31
32static void rtc_write (uchar reg, uchar val)
33{
6d0f6bcf 34 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
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35 udelay(2500);
36}
37
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38/* ------------------------------------------------------------------------- */
39
b73a19e1 40int rtc_get (struct rtc_time *tmp)
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41{
42 uchar sec, min, hour, mday, wday, mon, cent, year;
43 int retry = 1;
44
45 do {
46 sec = rtc_read (0x80);
47 min = rtc_read (0x82);
48 hour = rtc_read (0x84);
49 mday = rtc_read (0x86);
50 mon = rtc_read (0x88);
51 wday = rtc_read (0x8a);
52 year = rtc_read (0x8c);
53 cent = rtc_read (0x92);
54 /*
55 * Check for seconds rollover
56 */
57 if ((sec != 59) || (rtc_read(0x80) == sec)){
58 retry = 0;
59 }
60 } while (retry);
61
62 debug ( "Get RTC year: %02x mon: %02x cent: %02x mday: %02x wday: %02x "
63 "hr: %02x min: %02x sec: %02x\n",
64 year, mon, cent, mday, wday,
65 hour, min, sec );
66
67 tmp->tm_sec = bcd2bin (sec & 0x7F);
68 tmp->tm_min = bcd2bin (min & 0x7F);
69 tmp->tm_hour = bcd2bin (hour & 0x3F);
70 tmp->tm_mday = bcd2bin (mday & 0x3F);
71 tmp->tm_mon = bcd2bin (mon & 0x1F);
72 tmp->tm_year = bcd2bin (year) + bcd2bin(cent) * 100;
73 tmp->tm_wday = bcd2bin (wday & 0x07);
74 tmp->tm_yday = 0;
75 tmp->tm_isdst= 0;
76
77 debug ( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
78 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
79 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
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80
81 return 0;
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82}
83
d1e23194 84int rtc_set (struct rtc_time *tmp)
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85{
86
87 debug ( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
88 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
89 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
90
91 rtc_write (0x9E, 0x00);
92 rtc_write (0x80, 0); /* Clear seconds to ensure no rollover */
93 rtc_write (0x92, bin2bcd(tmp->tm_year / 100));
94 rtc_write (0x8c, bin2bcd(tmp->tm_year % 100));
95 rtc_write (0x8a, bin2bcd(tmp->tm_wday));
96 rtc_write (0x88, bin2bcd(tmp->tm_mon));
97 rtc_write (0x86, bin2bcd(tmp->tm_mday));
98 rtc_write (0x84, bin2bcd(tmp->tm_hour));
99 rtc_write (0x82, bin2bcd(tmp->tm_min ));
100 rtc_write (0x80, bin2bcd(tmp->tm_sec ));
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101
102 return 0;
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103}
104
105void rtc_reset (void)
106{
107}
108
068b60a0 109#endif