xref: /openbmc/u-boot/drivers/rtc/x1205.c (revision 26749582)
1 /*
2  * (C) Copyright 2007
3  * Stefan Roese, DENX Software Engineering, sr@denx.de.
4  *
5  * based on a the Linux rtc-x1207.c driver which is:
6  *	Copyright 2004 Karen Spearel
7  *	Copyright 2005 Alessandro Zummo
8  *
9  * Information and datasheet:
10  * http://www.intersil.com/cda/deviceinfo/0,1477,X1205,00.html
11  *
12  * See file CREDITS for list of people who contributed to this
13  * project.
14  *
15  * This program is free software; you can redistribute it and/or
16  * modify it under the terms of the GNU General Public License as
17  * published by the Free Software Foundation; either version 2 of
18  * the License, or (at your option) any later version.
19  *
20  * This program is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23  * GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with this program; if not, write to the Free Software
27  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
28  * MA 02111-1307 USA
29  */
30 
31 /*
32  * Date & Time support for Xicor/Intersil X1205 RTC
33  */
34 
35 /* #define	DEBUG	*/
36 
37 #include <common.h>
38 #include <command.h>
39 #include <rtc.h>
40 #include <i2c.h>
41 
42 #if defined(CONFIG_CMD_DATE)
43 
44 #define CCR_SEC			0
45 #define CCR_MIN			1
46 #define CCR_HOUR		2
47 #define CCR_MDAY		3
48 #define CCR_MONTH		4
49 #define CCR_YEAR		5
50 #define CCR_WDAY		6
51 #define CCR_Y2K			7
52 
53 #define X1205_REG_SR		0x3F	/* status register */
54 #define X1205_REG_Y2K		0x37
55 #define X1205_REG_DW		0x36
56 #define X1205_REG_YR		0x35
57 #define X1205_REG_MO		0x34
58 #define X1205_REG_DT		0x33
59 #define X1205_REG_HR		0x32
60 #define X1205_REG_MN		0x31
61 #define X1205_REG_SC		0x30
62 #define X1205_REG_DTR		0x13
63 #define X1205_REG_ATR		0x12
64 #define X1205_REG_INT		0x11
65 #define X1205_REG_0		0x10
66 #define X1205_REG_Y2K1		0x0F
67 #define X1205_REG_DWA1		0x0E
68 #define X1205_REG_YRA1		0x0D
69 #define X1205_REG_MOA1		0x0C
70 #define X1205_REG_DTA1		0x0B
71 #define X1205_REG_HRA1		0x0A
72 #define X1205_REG_MNA1		0x09
73 #define X1205_REG_SCA1		0x08
74 #define X1205_REG_Y2K0		0x07
75 #define X1205_REG_DWA0		0x06
76 #define X1205_REG_YRA0		0x05
77 #define X1205_REG_MOA0		0x04
78 #define X1205_REG_DTA0		0x03
79 #define X1205_REG_HRA0		0x02
80 #define X1205_REG_MNA0		0x01
81 #define X1205_REG_SCA0		0x00
82 
83 #define X1205_CCR_BASE		0x30	/* Base address of CCR */
84 #define X1205_ALM0_BASE		0x00	/* Base address of ALARM0 */
85 
86 #define X1205_SR_RTCF		0x01	/* Clock failure */
87 #define X1205_SR_WEL		0x02	/* Write Enable Latch */
88 #define X1205_SR_RWEL		0x04	/* Register Write Enable */
89 
90 #define X1205_DTR_DTR0		0x01
91 #define X1205_DTR_DTR1		0x02
92 #define X1205_DTR_DTR2		0x04
93 
94 #define X1205_HR_MIL		0x80	/* Set in ccr.hour for 24 hr mode */
95 
96 static void rtc_write(int reg, u8 val)
97 {
98 	i2c_write(CONFIG_SYS_I2C_RTC_ADDR, reg, 2, &val, 1);
99 }
100 
101 /*
102  * In the routines that deal directly with the x1205 hardware, we use
103  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
104  * Epoch is initialized as 2000. Time is set to UTC.
105  */
106 int rtc_get(struct rtc_time *tm)
107 {
108 	u8 buf[8];
109 
110 	i2c_read(CONFIG_SYS_I2C_RTC_ADDR, X1205_CCR_BASE, 2, buf, 8);
111 
112 	debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
113 	      "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
114 	      __FUNCTION__,
115 	      buf[0], buf[1], buf[2], buf[3],
116 	      buf[4], buf[5], buf[6], buf[7]);
117 
118 	tm->tm_sec = bcd2bin(buf[CCR_SEC]);
119 	tm->tm_min = bcd2bin(buf[CCR_MIN]);
120 	tm->tm_hour = bcd2bin(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
121 	tm->tm_mday = bcd2bin(buf[CCR_MDAY]);
122 	tm->tm_mon = bcd2bin(buf[CCR_MONTH]); /* mon is 0-11 */
123 	tm->tm_year = bcd2bin(buf[CCR_YEAR])
124 		+ (bcd2bin(buf[CCR_Y2K]) * 100);
125 	tm->tm_wday = buf[CCR_WDAY];
126 
127 	debug("%s: tm is secs=%d, mins=%d, hours=%d, "
128 	      "mday=%d, mon=%d, year=%d, wday=%d\n",
129 	      __FUNCTION__,
130 	      tm->tm_sec, tm->tm_min, tm->tm_hour,
131 	      tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
132 
133 	return 0;
134 }
135 
136 int rtc_set(struct rtc_time *tm)
137 {
138 	int i;
139 	u8 buf[8];
140 
141 	debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
142 	      tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
143 	      tm->tm_hour, tm->tm_min, tm->tm_sec);
144 
145 	buf[CCR_SEC] = bin2bcd(tm->tm_sec);
146 	buf[CCR_MIN] = bin2bcd(tm->tm_min);
147 
148 	/* set hour and 24hr bit */
149 	buf[CCR_HOUR] = bin2bcd(tm->tm_hour) | X1205_HR_MIL;
150 
151 	buf[CCR_MDAY] = bin2bcd(tm->tm_mday);
152 
153 	/* month, 1 - 12 */
154 	buf[CCR_MONTH] = bin2bcd(tm->tm_mon);
155 
156 	/* year, since the rtc epoch*/
157 	buf[CCR_YEAR] = bin2bcd(tm->tm_year % 100);
158 	buf[CCR_WDAY] = tm->tm_wday & 0x07;
159 	buf[CCR_Y2K] = bin2bcd(tm->tm_year / 100);
160 
161 	/* this sequence is required to unlock the chip */
162 	rtc_write(X1205_REG_SR, X1205_SR_WEL);
163 	rtc_write(X1205_REG_SR, X1205_SR_WEL | X1205_SR_RWEL);
164 
165 	/* write register's data */
166 	for (i = 0; i < 8; i++)
167 		rtc_write(X1205_CCR_BASE + i, buf[i]);
168 
169 	rtc_write(X1205_REG_SR, 0);
170 
171 	return 0;
172 }
173 
174 void rtc_reset(void)
175 {
176 	/*
177 	 * Nothing to do
178 	 */
179 }
180 
181 #endif
182