summaryrefslogtreecommitdiffstats
path: root/rtc/m41t11.c
blob: 11a1b086adaf6a1c8d3ad6cf1e2c37d9015bc9cb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
/*
 * (C) Copyright 2002
 * Andrew May, Viasat Inc, amay@viasat.com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

/*
 * M41T11 Serial Access Timekeeper(R) SRAM
 * can you believe a trademark on that?
 */

#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>

/*
	I Don't have an example config file but this
	is what should be done.

#define CONFIG_RTC_M41T11 1
#define CFG_I2C_RTC_ADDR 0x68
#if 0
#define CFG_M41T11_EXT_CENTURY_DATA
#else
#define CFG_M41T11_BASE_YEAR 2000
#endif
*/

#if defined(CONFIG_RTC_M41T11) && defined(CFG_I2C_RTC_ADDR) && (CONFIG_COMMANDS & CFG_CMD_DATE)

#define DEBUG 1

static unsigned bcd2bin (uchar n)
{
	return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
}

static unsigned char bin2bcd (unsigned int n)
{
	return (((n / 10) << 4) | (n % 10));
}


/* ------------------------------------------------------------------------- */
/*
  these are simple defines for the chip local to here so they aren't too
  verbose
  DAY/DATE aren't nice but that is how they are on the data sheet
*/
#define RTC_SEC_ADDR       0x0
#define RTC_MIN_ADDR       0x1
#define RTC_HOUR_ADDR      0x2
#define RTC_DAY_ADDR       0x3
#define RTC_DATE_ADDR      0x4
#define RTC_MONTH_ADDR     0x5
#define RTC_YEARS_ADDR     0x6

#define RTC_REG_CNT        7

#define RTC_CONTROL_ADDR   0x7


#ifndef CFG_M41T11_EXT_CENTURY_DATA

#define REG_CNT            (RTC_REG_CNT+1)

/*
  you only get 00-99 for the year we will asume you
  want from the year 2000 if you don't set the config
*/
#ifndef CFG_M41T11_BASE_YEAR
#define CFG_M41T11_BASE_YEAR 2000
#endif

#else
/* we will store extra year info in byte 9*/
#define M41T11_YEAR_DATA   0x8
#define M41T11_YEAR_SIZE   1
#define REG_CNT            (RTC_REG_CNT+1+M41T11_YEAR_SIZE)
#endif

#define M41T11_STORAGE_SZ  (64-REG_CNT)

void rtc_get (struct rtc_time *tmp)
{
	uchar data[RTC_REG_CNT];

	i2c_read(CFG_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);

	if( data[RTC_SEC_ADDR] & 0x80 ){
		printf( "m41t11 RTC Clock stopped!!!\n" );
	}
	tmp->tm_sec  = bcd2bin (data[RTC_SEC_ADDR]  & 0x7F);
	tmp->tm_min  = bcd2bin (data[RTC_MIN_ADDR]  & 0x7F);
	tmp->tm_hour = bcd2bin (data[RTC_HOUR_ADDR] & 0x3F);
	tmp->tm_mday = bcd2bin (data[RTC_DATE_ADDR] & 0x3F);
	tmp->tm_mon  = bcd2bin (data[RTC_MONTH_ADDR]& 0x1F);
#ifndef CFG_M41T11_EXT_CENTURY_DATA
	tmp->tm_year = CFG_M41T11_BASE_YEAR
		+ bcd2bin(data[RTC_YEARS_ADDR])
		+ ((data[RTC_HOUR_ADDR]&0x40) ? 100 : 0);
#else
	{
		unsigned char cent;
		i2c_read(CFG_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
		if( !(data[RTC_HOUR_ADDR] & 0x80) ){
			printf( "m41t11 RTC: cann't keep track of years without CEB set\n" );
		}
		if( (cent & 0x1) != ((data[RTC_HOUR_ADDR]&0x40)>>7) ){
			/*century flip store off new year*/
			cent += 1;
			i2c_write(CFG_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
		}
		tmp->tm_year =((int)cent*100)+bcd2bin(data[RTC_YEARS_ADDR]);
	}
#endif
	tmp->tm_wday = bcd2bin (data[RTC_DAY_ADDR]  & 0x07);
	tmp->tm_yday = 0;
	tmp->tm_isdst= 0;

	debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
}

void rtc_set (struct rtc_time *tmp)
{
	uchar data[RTC_REG_CNT];

	debug ( "Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);

	data[RTC_SEC_ADDR]    = bin2bcd(tmp->tm_sec) &  0x7F;/*just in case*/
	data[RTC_MIN_ADDR]    = bin2bcd(tmp->tm_min);
	data[RTC_HOUR_ADDR]   = bin2bcd(tmp->tm_hour) & 0x3F;/*handle cent stuff later*/
	data[RTC_DATE_ADDR]   = bin2bcd(tmp->tm_mday) & 0x3F;
	data[RTC_MONTH_ADDR]  = bin2bcd(tmp->tm_mon);
	data[RTC_DAY_ADDR]    = bin2bcd(tmp->tm_wday) & 0x07;

	data[RTC_HOUR_ADDR]   |= 0x80;/*we will always use CEB*/

	data[RTC_YEARS_ADDR]  = bin2bcd(tmp->tm_year%100);/*same thing either way*/
#ifndef CFG_M41T11_EXT_CENTURY_DATA
	if( ((tmp->tm_year - CFG_M41T11_BASE_YEAR) > 200) ||
	    (tmp->tm_year < CFG_M41T11_BASE_YEAR) ){
		printf( "m41t11 RTC setting year out of range!!need recompile\n" );
	}
	data[RTC_HOUR_ADDR] |= (tmp->tm_year - CFG_M41T11_BASE_YEAR) > 100 ? 0x40 : 0;
#else
	{
		unsigned char cent;
		cent = tmp->tm_year ? tmp->tm_year / 100 : 0;
		data[RTC_HOUR_ADDR] |= (cent & 0x1) ? 0x40 : 0;
		i2c_write(CFG_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, &cent, M41T11_YEAR_SIZE);
	}
#endif
	i2c_write(CFG_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
}

void rtc_reset (void)
{
	unsigned char val;
	/* clear all control & status registers */
	i2c_read(CFG_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, 1);
	val = val & 0x7F;/*make sure we are running*/
	i2c_write(CFG_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, RTC_REG_CNT);

	i2c_read(CFG_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
	val = val & 0x3F;/*turn off freq test keep calibration*/
	i2c_write(CFG_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
}

int rtc_store(int addr, unsigned char* data, int size)
{
	/*don't let things wrap onto the time on a write*/
	if( (addr+size) >= M41T11_STORAGE_SZ )
		return 1;
	return i2c_write( CFG_I2C_RTC_ADDR, REG_CNT+addr, 1, data, size );
}

int rtc_recall(int addr, unsigned char* data, int size)
{
	return i2c_read( CFG_I2C_RTC_ADDR, REG_CNT+addr, 1, data, size );
}

#endif /* CONFIG_RTC_M41T11 && CFG_I2C_RTC_ADDR && CFG_CMD_DATE */
OpenPOWER on IntegriCloud