xref: /openbmc/u-boot/drivers/rtc/x1205.c (revision 2146cf56)
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 #include <bcd.h>
42 
43 #if defined(CONFIG_RTC_X1205) && defined(CONFIG_CMD_DATE)
44 
45 #define CCR_SEC			0
46 #define CCR_MIN			1
47 #define CCR_HOUR		2
48 #define CCR_MDAY		3
49 #define CCR_MONTH		4
50 #define CCR_YEAR		5
51 #define CCR_WDAY		6
52 #define CCR_Y2K			7
53 
54 #define X1205_REG_SR		0x3F	/* status register */
55 #define X1205_REG_Y2K		0x37
56 #define X1205_REG_DW		0x36
57 #define X1205_REG_YR		0x35
58 #define X1205_REG_MO		0x34
59 #define X1205_REG_DT		0x33
60 #define X1205_REG_HR		0x32
61 #define X1205_REG_MN		0x31
62 #define X1205_REG_SC		0x30
63 #define X1205_REG_DTR		0x13
64 #define X1205_REG_ATR		0x12
65 #define X1205_REG_INT		0x11
66 #define X1205_REG_0		0x10
67 #define X1205_REG_Y2K1		0x0F
68 #define X1205_REG_DWA1		0x0E
69 #define X1205_REG_YRA1		0x0D
70 #define X1205_REG_MOA1		0x0C
71 #define X1205_REG_DTA1		0x0B
72 #define X1205_REG_HRA1		0x0A
73 #define X1205_REG_MNA1		0x09
74 #define X1205_REG_SCA1		0x08
75 #define X1205_REG_Y2K0		0x07
76 #define X1205_REG_DWA0		0x06
77 #define X1205_REG_YRA0		0x05
78 #define X1205_REG_MOA0		0x04
79 #define X1205_REG_DTA0		0x03
80 #define X1205_REG_HRA0		0x02
81 #define X1205_REG_MNA0		0x01
82 #define X1205_REG_SCA0		0x00
83 
84 #define X1205_CCR_BASE		0x30	/* Base address of CCR */
85 #define X1205_ALM0_BASE		0x00	/* Base address of ALARM0 */
86 
87 #define X1205_SR_RTCF		0x01	/* Clock failure */
88 #define X1205_SR_WEL		0x02	/* Write Enable Latch */
89 #define X1205_SR_RWEL		0x04	/* Register Write Enable */
90 
91 #define X1205_DTR_DTR0		0x01
92 #define X1205_DTR_DTR1		0x02
93 #define X1205_DTR_DTR2		0x04
94 
95 #define X1205_HR_MIL		0x80	/* Set in ccr.hour for 24 hr mode */
96 
97 static void rtc_write(int reg, u8 val)
98 {
99 	i2c_write(CFG_I2C_RTC_ADDR, reg, 2, &val, 1);
100 }
101 
102 /*
103  * In the routines that deal directly with the x1205 hardware, we use
104  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
105  * Epoch is initialized as 2000. Time is set to UTC.
106  */
107 void rtc_get(struct rtc_time *tm)
108 {
109 	u8 buf[8];
110 
111 	i2c_read(CFG_I2C_RTC_ADDR, X1205_CCR_BASE, 2, buf, 8);
112 
113 	debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
114 	      "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
115 	      __FUNCTION__,
116 	      buf[0], buf[1], buf[2], buf[3],
117 	      buf[4], buf[5], buf[6], buf[7]);
118 
119 	tm->tm_sec = BCD2BIN(buf[CCR_SEC]);
120 	tm->tm_min = BCD2BIN(buf[CCR_MIN]);
121 	tm->tm_hour = BCD2BIN(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
122 	tm->tm_mday = BCD2BIN(buf[CCR_MDAY]);
123 	tm->tm_mon = BCD2BIN(buf[CCR_MONTH]); /* mon is 0-11 */
124 	tm->tm_year = BCD2BIN(buf[CCR_YEAR])
125 		+ (BCD2BIN(buf[CCR_Y2K]) * 100);
126 	tm->tm_wday = buf[CCR_WDAY];
127 
128 	debug("%s: tm is secs=%d, mins=%d, hours=%d, "
129 	      "mday=%d, mon=%d, year=%d, wday=%d\n",
130 	      __FUNCTION__,
131 	      tm->tm_sec, tm->tm_min, tm->tm_hour,
132 	      tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
133 }
134 
135 void rtc_set(struct rtc_time *tm)
136 {
137 	int i;
138 	u8 buf[8];
139 
140 	debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
141 	      tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
142 	      tm->tm_hour, tm->tm_min, tm->tm_sec);
143 
144 	buf[CCR_SEC] = BIN2BCD(tm->tm_sec);
145 	buf[CCR_MIN] = BIN2BCD(tm->tm_min);
146 
147 	/* set hour and 24hr bit */
148 	buf[CCR_HOUR] = BIN2BCD(tm->tm_hour) | X1205_HR_MIL;
149 
150 	buf[CCR_MDAY] = BIN2BCD(tm->tm_mday);
151 
152 	/* month, 1 - 12 */
153 	buf[CCR_MONTH] = BIN2BCD(tm->tm_mon);
154 
155 	/* year, since the rtc epoch*/
156 	buf[CCR_YEAR] = BIN2BCD(tm->tm_year % 100);
157 	buf[CCR_WDAY] = tm->tm_wday & 0x07;
158 	buf[CCR_Y2K] = BIN2BCD(tm->tm_year / 100);
159 
160 	/* this sequence is required to unlock the chip */
161 	rtc_write(X1205_REG_SR, X1205_SR_WEL);
162 	rtc_write(X1205_REG_SR, X1205_SR_WEL | X1205_SR_RWEL);
163 
164 	/* write register's data */
165 	for (i = 0; i < 8; i++)
166 		rtc_write(X1205_CCR_BASE + i, buf[i]);
167 
168 	rtc_write(X1205_REG_SR, 0);
169 }
170 
171 void rtc_reset(void)
172 {
173 	/*
174 	 * Nothing to do
175 	 */
176 }
177 
178 #endif
179