xref: /openbmc/u-boot/drivers/rtc/x1205.c (revision 0bdea7c4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2007
4  * Stefan Roese, DENX Software Engineering, sr@denx.de.
5  *
6  * based on a the Linux rtc-x1207.c driver which is:
7  *	Copyright 2004 Karen Spearel
8  *	Copyright 2005 Alessandro Zummo
9  *
10  * Information and datasheet:
11  * http://www.intersil.com/cda/deviceinfo/0,1477,X1205,00.html
12  */
13 
14 /*
15  * Date & Time support for Xicor/Intersil X1205 RTC
16  */
17 
18 /* #define	DEBUG	*/
19 
20 #include <common.h>
21 #include <command.h>
22 #include <rtc.h>
23 #include <i2c.h>
24 
25 #define CCR_SEC			0
26 #define CCR_MIN			1
27 #define CCR_HOUR		2
28 #define CCR_MDAY		3
29 #define CCR_MONTH		4
30 #define CCR_YEAR		5
31 #define CCR_WDAY		6
32 #define CCR_Y2K			7
33 
34 #define X1205_REG_SR		0x3F	/* status register */
35 #define X1205_REG_Y2K		0x37
36 #define X1205_REG_DW		0x36
37 #define X1205_REG_YR		0x35
38 #define X1205_REG_MO		0x34
39 #define X1205_REG_DT		0x33
40 #define X1205_REG_HR		0x32
41 #define X1205_REG_MN		0x31
42 #define X1205_REG_SC		0x30
43 #define X1205_REG_DTR		0x13
44 #define X1205_REG_ATR		0x12
45 #define X1205_REG_INT		0x11
46 #define X1205_REG_0		0x10
47 #define X1205_REG_Y2K1		0x0F
48 #define X1205_REG_DWA1		0x0E
49 #define X1205_REG_YRA1		0x0D
50 #define X1205_REG_MOA1		0x0C
51 #define X1205_REG_DTA1		0x0B
52 #define X1205_REG_HRA1		0x0A
53 #define X1205_REG_MNA1		0x09
54 #define X1205_REG_SCA1		0x08
55 #define X1205_REG_Y2K0		0x07
56 #define X1205_REG_DWA0		0x06
57 #define X1205_REG_YRA0		0x05
58 #define X1205_REG_MOA0		0x04
59 #define X1205_REG_DTA0		0x03
60 #define X1205_REG_HRA0		0x02
61 #define X1205_REG_MNA0		0x01
62 #define X1205_REG_SCA0		0x00
63 
64 #define X1205_CCR_BASE		0x30	/* Base address of CCR */
65 #define X1205_ALM0_BASE		0x00	/* Base address of ALARM0 */
66 
67 #define X1205_SR_RTCF		0x01	/* Clock failure */
68 #define X1205_SR_WEL		0x02	/* Write Enable Latch */
69 #define X1205_SR_RWEL		0x04	/* Register Write Enable */
70 
71 #define X1205_DTR_DTR0		0x01
72 #define X1205_DTR_DTR1		0x02
73 #define X1205_DTR_DTR2		0x04
74 
75 #define X1205_HR_MIL		0x80	/* Set in ccr.hour for 24 hr mode */
76 
77 static void rtc_write(int reg, u8 val)
78 {
79 	i2c_write(CONFIG_SYS_I2C_RTC_ADDR, reg, 2, &val, 1);
80 }
81 
82 /*
83  * In the routines that deal directly with the x1205 hardware, we use
84  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
85  * Epoch is initialized as 2000. Time is set to UTC.
86  */
87 int rtc_get(struct rtc_time *tm)
88 {
89 	u8 buf[8];
90 
91 	i2c_read(CONFIG_SYS_I2C_RTC_ADDR, X1205_CCR_BASE, 2, buf, 8);
92 
93 	debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
94 	      "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
95 	      __FUNCTION__,
96 	      buf[0], buf[1], buf[2], buf[3],
97 	      buf[4], buf[5], buf[6], buf[7]);
98 
99 	tm->tm_sec = bcd2bin(buf[CCR_SEC]);
100 	tm->tm_min = bcd2bin(buf[CCR_MIN]);
101 	tm->tm_hour = bcd2bin(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
102 	tm->tm_mday = bcd2bin(buf[CCR_MDAY]);
103 	tm->tm_mon = bcd2bin(buf[CCR_MONTH]); /* mon is 0-11 */
104 	tm->tm_year = bcd2bin(buf[CCR_YEAR])
105 		+ (bcd2bin(buf[CCR_Y2K]) * 100);
106 	tm->tm_wday = buf[CCR_WDAY];
107 
108 	debug("%s: tm is secs=%d, mins=%d, hours=%d, "
109 	      "mday=%d, mon=%d, year=%d, wday=%d\n",
110 	      __FUNCTION__,
111 	      tm->tm_sec, tm->tm_min, tm->tm_hour,
112 	      tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
113 
114 	return 0;
115 }
116 
117 int rtc_set(struct rtc_time *tm)
118 {
119 	int i;
120 	u8 buf[8];
121 
122 	debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
123 	      tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
124 	      tm->tm_hour, tm->tm_min, tm->tm_sec);
125 
126 	buf[CCR_SEC] = bin2bcd(tm->tm_sec);
127 	buf[CCR_MIN] = bin2bcd(tm->tm_min);
128 
129 	/* set hour and 24hr bit */
130 	buf[CCR_HOUR] = bin2bcd(tm->tm_hour) | X1205_HR_MIL;
131 
132 	buf[CCR_MDAY] = bin2bcd(tm->tm_mday);
133 
134 	/* month, 1 - 12 */
135 	buf[CCR_MONTH] = bin2bcd(tm->tm_mon);
136 
137 	/* year, since the rtc epoch*/
138 	buf[CCR_YEAR] = bin2bcd(tm->tm_year % 100);
139 	buf[CCR_WDAY] = tm->tm_wday & 0x07;
140 	buf[CCR_Y2K] = bin2bcd(tm->tm_year / 100);
141 
142 	/* this sequence is required to unlock the chip */
143 	rtc_write(X1205_REG_SR, X1205_SR_WEL);
144 	rtc_write(X1205_REG_SR, X1205_SR_WEL | X1205_SR_RWEL);
145 
146 	/* write register's data */
147 	for (i = 0; i < 8; i++)
148 		rtc_write(X1205_CCR_BASE + i, buf[i]);
149 
150 	rtc_write(X1205_REG_SR, 0);
151 
152 	return 0;
153 }
154 
155 void rtc_reset(void)
156 {
157 	/*
158 	 * Nothing to do
159 	 */
160 }
161