xref: /openbmc/u-boot/drivers/rtc/rx8025.c (revision fc82e768)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2007
4  * Matthias Fuchs, esd gmbh, matthias.fuchs@esd-electronics.com.
5  */
6 
7 /*
8  * Epson RX8025 RTC driver.
9  */
10 
11 #include <common.h>
12 #include <command.h>
13 #include <rtc.h>
14 #include <i2c.h>
15 
16 /*---------------------------------------------------------------------*/
17 #undef DEBUG_RTC
18 
19 #ifdef DEBUG_RTC
20 #define DEBUGR(fmt,args...) printf(fmt ,##args)
21 #else
22 #define DEBUGR(fmt,args...)
23 #endif
24 /*---------------------------------------------------------------------*/
25 
26 #ifndef CONFIG_SYS_I2C_RTC_ADDR
27 # define CONFIG_SYS_I2C_RTC_ADDR	0x32
28 #endif
29 
30 /*
31  * RTC register addresses
32  */
33 #define RTC_SEC_REG_ADDR	0x00
34 #define RTC_MIN_REG_ADDR	0x01
35 #define RTC_HR_REG_ADDR		0x02
36 #define RTC_DAY_REG_ADDR	0x03
37 #define RTC_DATE_REG_ADDR	0x04
38 #define RTC_MON_REG_ADDR	0x05
39 #define RTC_YR_REG_ADDR		0x06
40 
41 #define RTC_CTL1_REG_ADDR	0x0e
42 #define RTC_CTL2_REG_ADDR	0x0f
43 
44 /*
45  * Control register 1 bits
46  */
47 #define RTC_CTL1_BIT_2412	0x20
48 
49 /*
50  * Control register 2 bits
51  */
52 #define RTC_CTL2_BIT_PON	0x10
53 #define RTC_CTL2_BIT_VDET	0x40
54 #define RTC_CTL2_BIT_XST	0x20
55 #define RTC_CTL2_BIT_VDSL	0x80
56 
57 /*
58  * Note: the RX8025 I2C RTC requires register
59  * reads and write to consist of a single bus
60  * cycle. It is not allowed to write the register
61  * address in a first cycle that is terminated by
62  * a STOP condition. The chips needs a 'restart'
63  * sequence (start sequence without a prior stop).
64  * This driver has been written for a 4xx board.
65  * U-Boot's 4xx i2c driver is currently not capable
66  * to generate such cycles to some work arounds
67  * are used.
68  */
69 
70 /* static uchar rtc_read (uchar reg); */
71 #define rtc_read(reg) buf[((reg) + 1) & 0xf]
72 
73 static void rtc_write (uchar reg, uchar val);
74 
75 /*
76  * Get the current time from the RTC
77  */
rtc_get(struct rtc_time * tmp)78 int rtc_get (struct rtc_time *tmp)
79 {
80 	int rel = 0;
81 	uchar sec, min, hour, mday, wday, mon, year, ctl2;
82 	uchar buf[16];
83 
84 	if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 16))
85 		printf("Error reading from RTC\n");
86 
87 	sec = rtc_read(RTC_SEC_REG_ADDR);
88 	min = rtc_read(RTC_MIN_REG_ADDR);
89 	hour = rtc_read(RTC_HR_REG_ADDR);
90 	wday = rtc_read(RTC_DAY_REG_ADDR);
91 	mday = rtc_read(RTC_DATE_REG_ADDR);
92 	mon = rtc_read(RTC_MON_REG_ADDR);
93 	year = rtc_read(RTC_YR_REG_ADDR);
94 
95 	DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
96 		"hr: %02x min: %02x sec: %02x\n",
97 		year, mon, mday, wday, hour, min, sec);
98 
99 	/* dump status */
100 	ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
101 	if (ctl2 & RTC_CTL2_BIT_PON) {
102 		printf("RTC: power-on detected\n");
103 		rel = -1;
104 	}
105 
106 	if (ctl2 & RTC_CTL2_BIT_VDET) {
107 		printf("RTC: voltage drop detected\n");
108 		rel = -1;
109 	}
110 
111 	if (!(ctl2 & RTC_CTL2_BIT_XST)) {
112 		printf("RTC: oscillator stop detected\n");
113 		rel = -1;
114 	}
115 
116 	tmp->tm_sec  = bcd2bin (sec & 0x7F);
117 	tmp->tm_min  = bcd2bin (min & 0x7F);
118 	if (rtc_read(RTC_CTL1_REG_ADDR) & RTC_CTL1_BIT_2412)
119 		tmp->tm_hour = bcd2bin (hour & 0x3F);
120 	else
121 		tmp->tm_hour = bcd2bin (hour & 0x1F) % 12 +
122 			       ((hour & 0x20) ? 12 : 0);
123 	tmp->tm_mday = bcd2bin (mday & 0x3F);
124 	tmp->tm_mon  = bcd2bin (mon & 0x1F);
125 	tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
126 	tmp->tm_wday = bcd2bin (wday & 0x07);
127 	tmp->tm_yday = 0;
128 	tmp->tm_isdst= 0;
129 
130 	DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
131 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
132 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
133 
134 	return rel;
135 }
136 
137 /*
138  * Set the RTC
139  */
rtc_set(struct rtc_time * tmp)140 int rtc_set (struct rtc_time *tmp)
141 {
142 	DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
143 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
144 		tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
145 
146 	if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
147 		printf("WARNING: year should be between 1970 and 2069!\n");
148 
149 	rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
150 	rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
151 	rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday));
152 	rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
153 	rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
154 	rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
155 	rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
156 
157 	rtc_write (RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412);
158 
159 	return 0;
160 }
161 
162 /*
163  * Reset the RTC
164  */
rtc_reset(void)165 void rtc_reset (void)
166 {
167 	uchar buf[16];
168 	uchar ctl2;
169 
170 	if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0,    0,   buf, 16))
171 		printf("Error reading from RTC\n");
172 
173 	ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
174 	ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET);
175 	ctl2 |= RTC_CTL2_BIT_XST | RTC_CTL2_BIT_VDSL;
176 	rtc_write (RTC_CTL2_REG_ADDR, ctl2);
177 }
178 
179 /*
180  * Helper functions
181  */
rtc_write(uchar reg,uchar val)182 static void rtc_write (uchar reg, uchar val)
183 {
184 	uchar buf[2];
185 	buf[0] = reg << 4;
186 	buf[1] = val;
187 	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 2) != 0)
188 		printf("Error writing to RTC\n");
189 
190 }
191