1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2002
4 * Andrew May, Viasat Inc, amay@viasat.com
5 */
6
7 /*
8 * M41T11 Serial Access Timekeeper(R) SRAM
9 * can you believe a trademark on that?
10 */
11
12 /* #define DEBUG 1 */
13
14 #include <common.h>
15 #include <command.h>
16 #include <rtc.h>
17 #include <i2c.h>
18
19 /*
20 I Don't have an example config file but this
21 is what should be done.
22
23 #define CONFIG_RTC_M41T11 1
24 #define CONFIG_SYS_I2C_RTC_ADDR 0x68
25 #if 0
26 #define CONFIG_SYS_M41T11_EXT_CENTURY_DATA
27 #else
28 #define CONFIG_SYS_M41T11_BASE_YEAR 2000
29 #endif
30 */
31
32 #if defined(CONFIG_SYS_I2C_RTC_ADDR) && defined(CONFIG_CMD_DATE)
33
34 /* ------------------------------------------------------------------------- */
35 /*
36 these are simple defines for the chip local to here so they aren't too
37 verbose
38 DAY/DATE aren't nice but that is how they are on the data sheet
39 */
40 #define RTC_SEC_ADDR 0x0
41 #define RTC_MIN_ADDR 0x1
42 #define RTC_HOUR_ADDR 0x2
43 #define RTC_DAY_ADDR 0x3
44 #define RTC_DATE_ADDR 0x4
45 #define RTC_MONTH_ADDR 0x5
46 #define RTC_YEARS_ADDR 0x6
47
48 #define RTC_REG_CNT 7
49
50 #define RTC_CONTROL_ADDR 0x7
51
52
53 #ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
54
55 #define REG_CNT (RTC_REG_CNT+1)
56
57 /*
58 you only get 00-99 for the year we will asume you
59 want from the year 2000 if you don't set the config
60 */
61 #ifndef CONFIG_SYS_M41T11_BASE_YEAR
62 #define CONFIG_SYS_M41T11_BASE_YEAR 2000
63 #endif
64
65 #else
66 /* we will store extra year info in byte 9*/
67 #define M41T11_YEAR_DATA 0x8
68 #define M41T11_YEAR_SIZE 1
69 #define REG_CNT (RTC_REG_CNT+1+M41T11_YEAR_SIZE)
70 #endif
71
72 #define M41T11_STORAGE_SZ (64-REG_CNT)
73
rtc_get(struct rtc_time * tmp)74 int rtc_get (struct rtc_time *tmp)
75 {
76 int rel = 0;
77 uchar data[RTC_REG_CNT];
78
79 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
80
81 if( data[RTC_SEC_ADDR] & 0x80 ){
82 printf( "m41t11 RTC Clock stopped!!!\n" );
83 rel = -1;
84 }
85 tmp->tm_sec = bcd2bin (data[RTC_SEC_ADDR] & 0x7F);
86 tmp->tm_min = bcd2bin (data[RTC_MIN_ADDR] & 0x7F);
87 tmp->tm_hour = bcd2bin (data[RTC_HOUR_ADDR] & 0x3F);
88 tmp->tm_mday = bcd2bin (data[RTC_DATE_ADDR] & 0x3F);
89 tmp->tm_mon = bcd2bin (data[RTC_MONTH_ADDR]& 0x1F);
90 #ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
91 tmp->tm_year = CONFIG_SYS_M41T11_BASE_YEAR
92 + bcd2bin(data[RTC_YEARS_ADDR])
93 + ((data[RTC_HOUR_ADDR]&0x40) ? 100 : 0);
94 #else
95 {
96 unsigned char cent;
97 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, ¢, M41T11_YEAR_SIZE);
98 if( !(data[RTC_HOUR_ADDR] & 0x80) ){
99 printf( "m41t11 RTC: cann't keep track of years without CEB set\n" );
100 rel = -1;
101 }
102 if( (cent & 0x1) != ((data[RTC_HOUR_ADDR]&0x40)>>7) ){
103 /*century flip store off new year*/
104 cent += 1;
105 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, ¢, M41T11_YEAR_SIZE);
106 }
107 tmp->tm_year =((int)cent*100)+bcd2bin(data[RTC_YEARS_ADDR]);
108 }
109 #endif
110 tmp->tm_wday = bcd2bin (data[RTC_DAY_ADDR] & 0x07);
111 tmp->tm_yday = 0;
112 tmp->tm_isdst= 0;
113
114 debug ( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
115 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
116 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
117
118 return rel;
119 }
120
rtc_set(struct rtc_time * tmp)121 int rtc_set (struct rtc_time *tmp)
122 {
123 uchar data[RTC_REG_CNT];
124
125 debug ( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
126 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
127 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
128
129 data[RTC_SEC_ADDR] = bin2bcd(tmp->tm_sec) & 0x7F;/*just in case*/
130 data[RTC_MIN_ADDR] = bin2bcd(tmp->tm_min);
131 data[RTC_HOUR_ADDR] = bin2bcd(tmp->tm_hour) & 0x3F;/*handle cent stuff later*/
132 data[RTC_DATE_ADDR] = bin2bcd(tmp->tm_mday) & 0x3F;
133 data[RTC_MONTH_ADDR] = bin2bcd(tmp->tm_mon);
134 data[RTC_DAY_ADDR] = bin2bcd(tmp->tm_wday) & 0x07;
135
136 data[RTC_HOUR_ADDR] |= 0x80;/*we will always use CEB*/
137
138 data[RTC_YEARS_ADDR] = bin2bcd(tmp->tm_year%100);/*same thing either way*/
139 #ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
140 if( ((tmp->tm_year - CONFIG_SYS_M41T11_BASE_YEAR) > 200) ||
141 (tmp->tm_year < CONFIG_SYS_M41T11_BASE_YEAR) ){
142 printf( "m41t11 RTC setting year out of range!!need recompile\n" );
143 }
144 data[RTC_HOUR_ADDR] |= (tmp->tm_year - CONFIG_SYS_M41T11_BASE_YEAR) > 100 ? 0x40 : 0;
145 #else
146 {
147 unsigned char cent;
148 cent = tmp->tm_year ? tmp->tm_year / 100 : 0;
149 data[RTC_HOUR_ADDR] |= (cent & 0x1) ? 0x40 : 0;
150 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, ¢, M41T11_YEAR_SIZE);
151 }
152 #endif
153 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
154
155 return 0;
156 }
157
rtc_reset(void)158 void rtc_reset (void)
159 {
160 unsigned char val;
161 /* clear all control & status registers */
162 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, 1);
163 val = val & 0x7F;/*make sure we are running*/
164 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, RTC_REG_CNT);
165
166 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
167 val = val & 0x3F;/*turn off freq test keep calibration*/
168 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
169 }
170 #endif
171