xref: /openbmc/u-boot/drivers/rtc/rx8025.c (revision 419adbfb)
1 /*
2  * (C) Copyright 2007
3  * Matthias Fuchs, esd gmbh, matthias.fuchs@esd-electronics.com.
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  * Epson RX8025 RTC driver.
26  */
27 
28 #include <common.h>
29 #include <command.h>
30 #include <rtc.h>
31 #include <i2c.h>
32 
33 #if defined(CONFIG_CMD_DATE)
34 
35 /*---------------------------------------------------------------------*/
36 #undef DEBUG_RTC
37 
38 #ifdef DEBUG_RTC
39 #define DEBUGR(fmt,args...) printf(fmt ,##args)
40 #else
41 #define DEBUGR(fmt,args...)
42 #endif
43 /*---------------------------------------------------------------------*/
44 
45 #ifndef CONFIG_SYS_I2C_RTC_ADDR
46 # define CONFIG_SYS_I2C_RTC_ADDR	0x32
47 #endif
48 
49 /*
50  * RTC register addresses
51  */
52 #define RTC_SEC_REG_ADDR	0x00
53 #define RTC_MIN_REG_ADDR	0x01
54 #define RTC_HR_REG_ADDR		0x02
55 #define RTC_DAY_REG_ADDR	0x03
56 #define RTC_DATE_REG_ADDR	0x04
57 #define RTC_MON_REG_ADDR	0x05
58 #define RTC_YR_REG_ADDR		0x06
59 
60 #define RTC_CTL1_REG_ADDR	0x0e
61 #define RTC_CTL2_REG_ADDR	0x0f
62 
63 /*
64  * Control register 1 bits
65  */
66 #define RTC_CTL1_BIT_2412	0x20
67 
68 /*
69  * Control register 2 bits
70  */
71 #define RTC_CTL2_BIT_PON	0x10
72 #define RTC_CTL2_BIT_VDET	0x40
73 #define RTC_CTL2_BIT_XST	0x20
74 #define RTC_CTL2_BIT_VDSL	0x80
75 
76 /*
77  * Note: the RX8025 I2C RTC requires register
78  * reads and write to consist of a single bus
79  * cycle. It is not allowed to write the register
80  * address in a first cycle that is terminated by
81  * a STOP condition. The chips needs a 'restart'
82  * sequence (start sequence without a prior stop).
83  * This driver has been written for a 4xx board.
84  * U-Boot's 4xx i2c driver is currently not capable
85  * to generate such cycles to some work arounds
86  * are used.
87  */
88 
89 /* static uchar rtc_read (uchar reg); */
90 #define rtc_read(reg) buf[((reg) + 1) & 0xf]
91 
92 static void rtc_write (uchar reg, uchar val);
93 
94 /*
95  * Get the current time from the RTC
96  */
97 int rtc_get (struct rtc_time *tmp)
98 {
99 	int rel = 0;
100 	uchar sec, min, hour, mday, wday, mon, year, ctl2;
101 	uchar buf[16];
102 
103 	if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 16))
104 		printf("Error reading from RTC\n");
105 
106 	sec = rtc_read(RTC_SEC_REG_ADDR);
107 	min = rtc_read(RTC_MIN_REG_ADDR);
108 	hour = rtc_read(RTC_HR_REG_ADDR);
109 	wday = rtc_read(RTC_DAY_REG_ADDR);
110 	mday = rtc_read(RTC_DATE_REG_ADDR);
111 	mon = rtc_read(RTC_MON_REG_ADDR);
112 	year = rtc_read(RTC_YR_REG_ADDR);
113 
114 	DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
115 		"hr: %02x min: %02x sec: %02x\n",
116 		year, mon, mday, wday, hour, min, sec);
117 
118 	/* dump status */
119 	ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
120 	if (ctl2 & RTC_CTL2_BIT_PON) {
121 		printf("RTC: power-on detected\n");
122 		rel = -1;
123 	}
124 
125 	if (ctl2 & RTC_CTL2_BIT_VDET) {
126 		printf("RTC: voltage drop detected\n");
127 		rel = -1;
128 	}
129 
130 	if (!(ctl2 & RTC_CTL2_BIT_XST)) {
131 		printf("RTC: oscillator stop detected\n");
132 		rel = -1;
133 	}
134 
135 	tmp->tm_sec  = bcd2bin (sec & 0x7F);
136 	tmp->tm_min  = bcd2bin (min & 0x7F);
137 	if (rtc_read(RTC_CTL1_REG_ADDR) & RTC_CTL1_BIT_2412)
138 		tmp->tm_hour = bcd2bin (hour & 0x3F);
139 	else
140 		tmp->tm_hour = bcd2bin (hour & 0x1F) % 12 +
141 			       ((hour & 0x20) ? 12 : 0);
142 	tmp->tm_mday = bcd2bin (mday & 0x3F);
143 	tmp->tm_mon  = bcd2bin (mon & 0x1F);
144 	tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
145 	tmp->tm_wday = bcd2bin (wday & 0x07);
146 	tmp->tm_yday = 0;
147 	tmp->tm_isdst= 0;
148 
149 	DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
150 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
151 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
152 
153 	return rel;
154 }
155 
156 /*
157  * Set the RTC
158  */
159 int rtc_set (struct rtc_time *tmp)
160 {
161 	DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
162 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
163 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
164 
165 	if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
166 		printf("WARNING: year should be between 1970 and 2069!\n");
167 
168 	rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
169 	rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
170 	rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday));
171 	rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
172 	rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
173 	rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
174 	rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
175 
176 	rtc_write (RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412);
177 
178 	return 0;
179 }
180 
181 /*
182  * Reset the RTC. We setting the date back to 1970-01-01.
183  */
184 void rtc_reset (void)
185 {
186 	struct rtc_time tmp;
187 	uchar buf[16];
188 	uchar ctl2;
189 
190 	if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0,    0,   buf, 16))
191 		printf("Error reading from RTC\n");
192 
193 	ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
194 	ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET);
195 	ctl2 |= RTC_CTL2_BIT_XST | RTC_CTL2_BIT_VDSL;
196 	rtc_write (RTC_CTL2_REG_ADDR, ctl2);
197 
198 	tmp.tm_year = 1970;
199 	tmp.tm_mon = 1;
200 	tmp.tm_mday= 1;
201 	tmp.tm_hour = 0;
202 	tmp.tm_min = 0;
203 	tmp.tm_sec = 0;
204 
205 	rtc_set(&tmp);
206 
207 	printf ( "RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
208 		tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
209 		tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
210 
211 	return;
212 }
213 
214 /*
215  * Helper functions
216  */
217 static void rtc_write (uchar reg, uchar val)
218 {
219 	uchar buf[2];
220 	buf[0] = reg << 4;
221 	buf[1] = val;
222 	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 2) != 0)
223 		printf("Error writing to RTC\n");
224 
225 }
226 
227 #endif /* CONFIG_RTC_RX8025 && CONFIG_CMD_DATE */
228