summaryrefslogtreecommitdiffstats
path: root/arch/mips/jmr3927/common/rtc_ds1742.c
blob: 1ae4318e1358fa6d8d02f0c26c2676743d827c47 (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
/*
 * Copyright 2001 MontaVista Software Inc.
 * Author: MontaVista Software, Inc.
 *              ahennessy@mvista.com
 *
 * arch/mips/jmr3927/common/rtc_ds1742.c
 * Based on arch/mips/ddb5xxx/common/rtc_ds1386.c
 *     low-level RTC hookups for s for Dallas 1742 chip.
 *
 * Copyright (C) 2000-2001 Toshiba Corporation
 *
 *  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  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  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.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */


/*
 * This file exports a function, rtc_ds1386_init(), which expects an
 * uncached base address as the argument.  It will set the two function
 * pointers expected by the MIPS generic timer code.
 */

#include <linux/bcd.h>
#include <linux/types.h>
#include <linux/time.h>
#include <linux/rtc.h>

#include <asm/time.h>
#include <asm/addrspace.h>

#include <asm/jmr3927/ds1742rtc.h>
#include <asm/debug.h>

#define	EPOCH		2000

static unsigned long rtc_base;

static unsigned long
rtc_ds1742_get_time(void)
{
	unsigned int year, month, day, hour, minute, second;
	unsigned int century;

	CMOS_WRITE(RTC_READ, RTC_CONTROL);
	second = BCD2BIN(CMOS_READ(RTC_SECONDS) & RTC_SECONDS_MASK);
	minute = BCD2BIN(CMOS_READ(RTC_MINUTES));
	hour = BCD2BIN(CMOS_READ(RTC_HOURS));
	day = BCD2BIN(CMOS_READ(RTC_DATE));
	month = BCD2BIN(CMOS_READ(RTC_MONTH));
	year = BCD2BIN(CMOS_READ(RTC_YEAR));
	century = BCD2BIN(CMOS_READ(RTC_CENTURY) & RTC_CENTURY_MASK);
	CMOS_WRITE(0, RTC_CONTROL);

	year += century * 100;

	return mktime(year, month, day, hour, minute, second);
}
extern void to_tm(unsigned long tim, struct rtc_time * tm);

static int
rtc_ds1742_set_time(unsigned long t)
{
	struct rtc_time tm;
	u8 year, month, day, hour, minute, second;
	u8 cmos_year, cmos_month, cmos_day, cmos_hour, cmos_minute, cmos_second;
	int cmos_century;

	CMOS_WRITE(RTC_READ, RTC_CONTROL);
	cmos_second = (u8)(CMOS_READ(RTC_SECONDS) & RTC_SECONDS_MASK);
	cmos_minute = (u8)CMOS_READ(RTC_MINUTES);
	cmos_hour = (u8)CMOS_READ(RTC_HOURS);
	cmos_day = (u8)CMOS_READ(RTC_DATE);
	cmos_month = (u8)CMOS_READ(RTC_MONTH);
	cmos_year = (u8)CMOS_READ(RTC_YEAR);
	cmos_century = CMOS_READ(RTC_CENTURY) & RTC_CENTURY_MASK;

	CMOS_WRITE(RTC_WRITE, RTC_CONTROL);

	/* convert */
	to_tm(t, &tm);

	/* check each field one by one */
	year = BIN2BCD(tm.tm_year - EPOCH);
	if (year != cmos_year) {
		CMOS_WRITE(year,RTC_YEAR);
	}

	month = BIN2BCD(tm.tm_mon);
	if (month != (cmos_month & 0x1f)) {
		CMOS_WRITE((month & 0x1f) | (cmos_month & ~0x1f),RTC_MONTH);
	}

	day = BIN2BCD(tm.tm_mday);
	if (day != cmos_day) {

		CMOS_WRITE(day, RTC_DATE);
	}

	if (cmos_hour & 0x40) {
		/* 12 hour format */
		hour = 0x40;
		if (tm.tm_hour > 12) {
			hour |= 0x20 | (BIN2BCD(hour-12) & 0x1f);
		} else {
			hour |= BIN2BCD(tm.tm_hour);
		}
	} else {
		/* 24 hour format */
		hour = BIN2BCD(tm.tm_hour) & 0x3f;
	}
	if (hour != cmos_hour) CMOS_WRITE(hour, RTC_HOURS);

	minute = BIN2BCD(tm.tm_min);
	if (minute !=  cmos_minute) {
		CMOS_WRITE(minute, RTC_MINUTES);
	}

	second = BIN2BCD(tm.tm_sec);
	if (second !=  cmos_second) {
		CMOS_WRITE(second & RTC_SECONDS_MASK,RTC_SECONDS);
	}

	/* RTC_CENTURY and RTC_CONTROL share same address... */
	CMOS_WRITE(cmos_century, RTC_CONTROL);

	return 0;
}

void
rtc_ds1742_init(unsigned long base)
{
	u8  cmos_second;

	/* remember the base */
	rtc_base = base;
	db_assert((rtc_base & 0xe0000000) == KSEG1);

	/* set the function pointers */
	rtc_get_time = rtc_ds1742_get_time;
	rtc_set_time = rtc_ds1742_set_time;

	/* clear oscillator stop bit */
	CMOS_WRITE(RTC_READ, RTC_CONTROL);
	cmos_second = (u8)(CMOS_READ(RTC_SECONDS) & RTC_SECONDS_MASK);
	CMOS_WRITE(RTC_WRITE, RTC_CONTROL);
	CMOS_WRITE(cmos_second, RTC_SECONDS); /* clear msb */
	CMOS_WRITE(0, RTC_CONTROL);
}
OpenPOWER on IntegriCloud