xref: /openbmc/u-boot/drivers/rtc/x1205.c (revision 8ee59472)
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 #if defined(CONFIG_CMD_DATE)
26 
27 #define CCR_SEC			0
28 #define CCR_MIN			1
29 #define CCR_HOUR		2
30 #define CCR_MDAY		3
31 #define CCR_MONTH		4
32 #define CCR_YEAR		5
33 #define CCR_WDAY		6
34 #define CCR_Y2K			7
35 
36 #define X1205_REG_SR		0x3F	/* status register */
37 #define X1205_REG_Y2K		0x37
38 #define X1205_REG_DW		0x36
39 #define X1205_REG_YR		0x35
40 #define X1205_REG_MO		0x34
41 #define X1205_REG_DT		0x33
42 #define X1205_REG_HR		0x32
43 #define X1205_REG_MN		0x31
44 #define X1205_REG_SC		0x30
45 #define X1205_REG_DTR		0x13
46 #define X1205_REG_ATR		0x12
47 #define X1205_REG_INT		0x11
48 #define X1205_REG_0		0x10
49 #define X1205_REG_Y2K1		0x0F
50 #define X1205_REG_DWA1		0x0E
51 #define X1205_REG_YRA1		0x0D
52 #define X1205_REG_MOA1		0x0C
53 #define X1205_REG_DTA1		0x0B
54 #define X1205_REG_HRA1		0x0A
55 #define X1205_REG_MNA1		0x09
56 #define X1205_REG_SCA1		0x08
57 #define X1205_REG_Y2K0		0x07
58 #define X1205_REG_DWA0		0x06
59 #define X1205_REG_YRA0		0x05
60 #define X1205_REG_MOA0		0x04
61 #define X1205_REG_DTA0		0x03
62 #define X1205_REG_HRA0		0x02
63 #define X1205_REG_MNA0		0x01
64 #define X1205_REG_SCA0		0x00
65 
66 #define X1205_CCR_BASE		0x30	/* Base address of CCR */
67 #define X1205_ALM0_BASE		0x00	/* Base address of ALARM0 */
68 
69 #define X1205_SR_RTCF		0x01	/* Clock failure */
70 #define X1205_SR_WEL		0x02	/* Write Enable Latch */
71 #define X1205_SR_RWEL		0x04	/* Register Write Enable */
72 
73 #define X1205_DTR_DTR0		0x01
74 #define X1205_DTR_DTR1		0x02
75 #define X1205_DTR_DTR2		0x04
76 
77 #define X1205_HR_MIL		0x80	/* Set in ccr.hour for 24 hr mode */
78 
79 static void rtc_write(int reg, u8 val)
80 {
81 	i2c_write(CONFIG_SYS_I2C_RTC_ADDR, reg, 2, &val, 1);
82 }
83 
84 /*
85  * In the routines that deal directly with the x1205 hardware, we use
86  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
87  * Epoch is initialized as 2000. Time is set to UTC.
88  */
89 int rtc_get(struct rtc_time *tm)
90 {
91 	u8 buf[8];
92 
93 	i2c_read(CONFIG_SYS_I2C_RTC_ADDR, X1205_CCR_BASE, 2, buf, 8);
94 
95 	debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
96 	      "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
97 	      __FUNCTION__,
98 	      buf[0], buf[1], buf[2], buf[3],
99 	      buf[4], buf[5], buf[6], buf[7]);
100 
101 	tm->tm_sec = bcd2bin(buf[CCR_SEC]);
102 	tm->tm_min = bcd2bin(buf[CCR_MIN]);
103 	tm->tm_hour = bcd2bin(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
104 	tm->tm_mday = bcd2bin(buf[CCR_MDAY]);
105 	tm->tm_mon = bcd2bin(buf[CCR_MONTH]); /* mon is 0-11 */
106 	tm->tm_year = bcd2bin(buf[CCR_YEAR])
107 		+ (bcd2bin(buf[CCR_Y2K]) * 100);
108 	tm->tm_wday = buf[CCR_WDAY];
109 
110 	debug("%s: tm is secs=%d, mins=%d, hours=%d, "
111 	      "mday=%d, mon=%d, year=%d, wday=%d\n",
112 	      __FUNCTION__,
113 	      tm->tm_sec, tm->tm_min, tm->tm_hour,
114 	      tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
115 
116 	return 0;
117 }
118 
119 int rtc_set(struct rtc_time *tm)
120 {
121 	int i;
122 	u8 buf[8];
123 
124 	debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
125 	      tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
126 	      tm->tm_hour, tm->tm_min, tm->tm_sec);
127 
128 	buf[CCR_SEC] = bin2bcd(tm->tm_sec);
129 	buf[CCR_MIN] = bin2bcd(tm->tm_min);
130 
131 	/* set hour and 24hr bit */
132 	buf[CCR_HOUR] = bin2bcd(tm->tm_hour) | X1205_HR_MIL;
133 
134 	buf[CCR_MDAY] = bin2bcd(tm->tm_mday);
135 
136 	/* month, 1 - 12 */
137 	buf[CCR_MONTH] = bin2bcd(tm->tm_mon);
138 
139 	/* year, since the rtc epoch*/
140 	buf[CCR_YEAR] = bin2bcd(tm->tm_year % 100);
141 	buf[CCR_WDAY] = tm->tm_wday & 0x07;
142 	buf[CCR_Y2K] = bin2bcd(tm->tm_year / 100);
143 
144 	/* this sequence is required to unlock the chip */
145 	rtc_write(X1205_REG_SR, X1205_SR_WEL);
146 	rtc_write(X1205_REG_SR, X1205_SR_WEL | X1205_SR_RWEL);
147 
148 	/* write register's data */
149 	for (i = 0; i < 8; i++)
150 		rtc_write(X1205_CCR_BASE + i, buf[i]);
151 
152 	rtc_write(X1205_REG_SR, 0);
153 
154 	return 0;
155 }
156 
157 void rtc_reset(void)
158 {
159 	/*
160 	 * Nothing to do
161 	 */
162 }
163 
164 #endif
165