summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/isl1208.c
blob: 07591b7dba790afc2fc5f871826c280a599b7e0c (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
/*
 * (C) Copyright 2008
 * Tor Krill, Excito Elektronik i Skåne , tor@excito.com
 *
 * Modelled after the ds1337 driver
 *
 * 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
 */

/*
 * Date & Time support (no alarms) for Intersil
 * ISL1208 Real Time Clock (RTC).
 */

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

/*---------------------------------------------------------------------*/
#ifdef DEBUG_RTC
#define DEBUGR(fmt,args...) printf(fmt ,##args)
#else
#define DEBUGR(fmt,args...)
#endif
/*---------------------------------------------------------------------*/

/*
 * RTC register addresses
 */

#define RTC_SEC_REG_ADDR	0x0
#define RTC_MIN_REG_ADDR	0x1
#define RTC_HR_REG_ADDR		0x2
#define RTC_DATE_REG_ADDR	0x3
#define RTC_MON_REG_ADDR	0x4
#define RTC_YR_REG_ADDR		0x5
#define RTC_DAY_REG_ADDR	0x6
#define RTC_STAT_REG_ADDR	0x7
/*
 * RTC control register bits
 */

/*
 * RTC status register bits
 */
#define RTC_STAT_BIT_ARST	0x80	/* AUTO RESET ENABLE BIT */
#define RTC_STAT_BIT_XTOSCB	0x40	/* CRYSTAL OSCILLATOR ENABLE BIT */
#define RTC_STAT_BIT_WRTC	0x10	/* WRITE RTC ENABLE BIT */
#define RTC_STAT_BIT_ALM	0x04	/* ALARM BIT */
#define RTC_STAT_BIT_BAT	0x02	/* BATTERY BIT */
#define RTC_STAT_BIT_RTCF	0x01	/* REAL TIME CLOCK FAIL BIT */

static uchar rtc_read (uchar reg);
static void rtc_write (uchar reg, uchar val);

/*
 * Get the current time from the RTC
 */

int rtc_get (struct rtc_time *tmp)
{
	int rel = 0;
	uchar sec, min, hour, mday, wday, mon, year, status;

	status = rtc_read (RTC_STAT_REG_ADDR);
	sec = rtc_read (RTC_SEC_REG_ADDR);
	min = rtc_read (RTC_MIN_REG_ADDR);
	hour = rtc_read (RTC_HR_REG_ADDR);
	wday = rtc_read (RTC_DAY_REG_ADDR);
	mday = rtc_read (RTC_DATE_REG_ADDR);
	mon = rtc_read (RTC_MON_REG_ADDR);
	year = rtc_read (RTC_YR_REG_ADDR);

	DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
		"hr: %02x min: %02x sec: %02x status: %02x\n",
		year, mon, mday, wday, hour, min, sec, status);

	if (status & RTC_STAT_BIT_RTCF) {
		printf ("### Warning: RTC oscillator has stopped\n");
		rtc_write(RTC_STAT_REG_ADDR,
			rtc_read(RTC_STAT_REG_ADDR) &~ (RTC_STAT_BIT_BAT|RTC_STAT_BIT_RTCF));
		rel = -1;
	}

	tmp->tm_sec  = bcd2bin (sec & 0x7F);
	tmp->tm_min  = bcd2bin (min & 0x7F);
	tmp->tm_hour = bcd2bin (hour & 0x3F);
	tmp->tm_mday = bcd2bin (mday & 0x3F);
	tmp->tm_mon  = bcd2bin (mon & 0x1F);
	tmp->tm_year = bcd2bin (year)+2000;
	tmp->tm_wday = bcd2bin (wday & 0x07);
	tmp->tm_yday = 0;
	tmp->tm_isdst= 0;

	DEBUGR ("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);

	return rel;
}

/*
 * Set the RTC
 */
int rtc_set (struct rtc_time *tmp)
{
	DEBUGR ("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);

	/* enable write */
	rtc_write(RTC_STAT_REG_ADDR,
		rtc_read(RTC_STAT_REG_ADDR) | RTC_STAT_BIT_WRTC);

	rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
	rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
	rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday));
	rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
	rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour) | 0x80 ); /* 24h clock */
	rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
	rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));

	/* disable write */
	rtc_write(RTC_STAT_REG_ADDR,
		rtc_read(RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_WRTC);

	return 0;
}

void rtc_reset (void)
{
}

/*
 * Helper functions
 */

static uchar rtc_read (uchar reg)
{
	return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
}

static void rtc_write (uchar reg, uchar val)
{
	i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
}
OpenPOWER on IntegriCloud