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