xref: /openbmc/u-boot/drivers/rtc/s3c24x0_rtc.c (revision ae03661f)
1 /*
2  * (C) Copyright 2003
3  * David Müller ELSOFT AG Switzerland. d.mueller@elsoft.ch
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 the built-in Samsung S3C24X0 RTC
26  */
27 
28 #include <common.h>
29 #include <command.h>
30 
31 #if (defined(CONFIG_CMD_DATE))
32 
33 #include <asm/arch/s3c24x0_cpu.h>
34 
35 #include <rtc.h>
36 #include <asm/io.h>
37 #include <linux/compiler.h>
38 
39 typedef enum {
40 	RTC_ENABLE,
41 	RTC_DISABLE
42 } RTC_ACCESS;
43 
44 
45 static inline void SetRTC_Access(RTC_ACCESS a)
46 {
47 	struct s3c24x0_rtc *rtc = s3c24x0_get_base_rtc();
48 
49 	switch (a) {
50 	case RTC_ENABLE:
51 		writeb(readb(&rtc->rtccon) | 0x01, &rtc->rtccon);
52 		break;
53 
54 	case RTC_DISABLE:
55 		writeb(readb(&rtc->rtccon) & ~0x01, &rtc->rtccon);
56 		break;
57 	}
58 }
59 
60 /* ------------------------------------------------------------------------- */
61 
62 int rtc_get(struct rtc_time *tmp)
63 {
64 	struct s3c24x0_rtc *rtc = s3c24x0_get_base_rtc();
65 	uchar sec, min, hour, mday, wday, mon, year;
66 	__maybe_unused uchar a_sec, a_min, a_hour, a_date,
67 			     a_mon, a_year, a_armed;
68 
69 	/* enable access to RTC registers */
70 	SetRTC_Access(RTC_ENABLE);
71 
72 	/* read RTC registers */
73 	do {
74 		sec  = readb(&rtc->bcdsec);
75 		min  = readb(&rtc->bcdmin);
76 		hour = readb(&rtc->bcdhour);
77 		mday = readb(&rtc->bcddate);
78 		wday = readb(&rtc->bcdday);
79 		mon  = readb(&rtc->bcdmon);
80 		year = readb(&rtc->bcdyear);
81 	} while (sec != readb(&rtc->bcdsec));
82 
83 	/* read ALARM registers */
84 	a_sec   = readb(&rtc->almsec);
85 	a_min   = readb(&rtc->almmin);
86 	a_hour  = readb(&rtc->almhour);
87 	a_date  = readb(&rtc->almdate);
88 	a_mon   = readb(&rtc->almmon);
89 	a_year  = readb(&rtc->almyear);
90 	a_armed = readb(&rtc->rtcalm);
91 
92 	/* disable access to RTC registers */
93 	SetRTC_Access(RTC_DISABLE);
94 
95 #ifdef RTC_DEBUG
96 	printf("Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
97 	       "hr: %02x min: %02x sec: %02x\n",
98 	       year, mon, mday, wday, hour, min, sec);
99 	printf("Alarms: %02x: year: %02x month: %02x date: %02x hour: "
100 	       "%02x min: %02x sec: %02x\n",
101 	       a_armed, a_year, a_mon, a_date, a_hour, a_min, a_sec);
102 #endif
103 
104 	tmp->tm_sec  = bcd2bin(sec & 0x7F);
105 	tmp->tm_min  = bcd2bin(min & 0x7F);
106 	tmp->tm_hour = bcd2bin(hour & 0x3F);
107 	tmp->tm_mday = bcd2bin(mday & 0x3F);
108 	tmp->tm_mon  = bcd2bin(mon & 0x1F);
109 	tmp->tm_year = bcd2bin(year);
110 	tmp->tm_wday = bcd2bin(wday & 0x07);
111 	if (tmp->tm_year < 70)
112 		tmp->tm_year += 2000;
113 	else
114 		tmp->tm_year += 1900;
115 	tmp->tm_yday  = 0;
116 	tmp->tm_isdst = 0;
117 #ifdef RTC_DEBUG
118 	printf("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
119 	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
120 	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
121 #endif
122 
123 	return 0;
124 }
125 
126 int rtc_set(struct rtc_time *tmp)
127 {
128 	struct s3c24x0_rtc *rtc = s3c24x0_get_base_rtc();
129 	uchar sec, min, hour, mday, wday, mon, year;
130 
131 #ifdef RTC_DEBUG
132 	printf("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
133 	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
134 	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
135 #endif
136 	year = bin2bcd(tmp->tm_year % 100);
137 	mon  = bin2bcd(tmp->tm_mon);
138 	wday = bin2bcd(tmp->tm_wday);
139 	mday = bin2bcd(tmp->tm_mday);
140 	hour = bin2bcd(tmp->tm_hour);
141 	min  = bin2bcd(tmp->tm_min);
142 	sec  = bin2bcd(tmp->tm_sec);
143 
144 	/* enable access to RTC registers */
145 	SetRTC_Access(RTC_ENABLE);
146 
147 	/* write RTC registers */
148 	writeb(sec, &rtc->bcdsec);
149 	writeb(min, &rtc->bcdmin);
150 	writeb(hour, &rtc->bcdhour);
151 	writeb(mday, &rtc->bcddate);
152 	writeb(wday, &rtc->bcdday);
153 	writeb(mon, &rtc->bcdmon);
154 	writeb(year, &rtc->bcdyear);
155 
156 	/* disable access to RTC registers */
157 	SetRTC_Access(RTC_DISABLE);
158 
159 	return 0;
160 }
161 
162 void rtc_reset(void)
163 {
164 	struct s3c24x0_rtc *rtc = s3c24x0_get_base_rtc();
165 
166 	writeb((readb(&rtc->rtccon) & ~0x06) | 0x08, &rtc->rtccon);
167 	writeb(readb(&rtc->rtccon) & ~(0x08 | 0x01), &rtc->rtccon);
168 }
169 
170 #endif
171