1 // SPDX-License-Identifier: GPL-2.0+
4 * Andrew May, Viasat Inc, amay@viasat.com
8 * M41T11 Serial Access Timekeeper(R) SRAM
9 * can you believe a trademark on that?
21 I Don't have an example config file but this
22 is what should be done.
24 #define CONFIG_RTC_M41T11 1
25 #define CONFIG_SYS_I2C_RTC_ADDR 0x68
27 #define CONFIG_SYS_M41T11_EXT_CENTURY_DATA
29 #define CONFIG_SYS_M41T11_BASE_YEAR 2000
33 /* ------------------------------------------------------------------------- */
35 these are simple defines for the chip local to here so they aren't too
37 DAY/DATE aren't nice but that is how they are on the data sheet
39 #define RTC_SEC_ADDR 0x0
40 #define RTC_MIN_ADDR 0x1
41 #define RTC_HOUR_ADDR 0x2
42 #define RTC_DAY_ADDR 0x3
43 #define RTC_DATE_ADDR 0x4
44 #define RTC_MONTH_ADDR 0x5
45 #define RTC_YEARS_ADDR 0x6
49 #define RTC_CONTROL_ADDR 0x7
52 #ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
54 #define REG_CNT (RTC_REG_CNT+1)
57 you only get 00-99 for the year we will asume you
58 want from the year 2000 if you don't set the config
60 #ifndef CONFIG_SYS_M41T11_BASE_YEAR
61 #define CONFIG_SYS_M41T11_BASE_YEAR 2000
65 /* we will store extra year info in byte 9*/
66 #define M41T11_YEAR_DATA 0x8
67 #define M41T11_YEAR_SIZE 1
68 #define REG_CNT (RTC_REG_CNT+1+M41T11_YEAR_SIZE)
71 #define M41T11_STORAGE_SZ (64-REG_CNT)
73 int rtc_get (struct rtc_time *tmp)
76 uchar data[RTC_REG_CNT];
78 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
80 if( data[RTC_SEC_ADDR] & 0x80 ){
81 printf( "m41t11 RTC Clock stopped!!!\n" );
84 tmp->tm_sec = bcd2bin (data[RTC_SEC_ADDR] & 0x7F);
85 tmp->tm_min = bcd2bin (data[RTC_MIN_ADDR] & 0x7F);
86 tmp->tm_hour = bcd2bin (data[RTC_HOUR_ADDR] & 0x3F);
87 tmp->tm_mday = bcd2bin (data[RTC_DATE_ADDR] & 0x3F);
88 tmp->tm_mon = bcd2bin (data[RTC_MONTH_ADDR]& 0x1F);
89 #ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
90 tmp->tm_year = CONFIG_SYS_M41T11_BASE_YEAR
91 + bcd2bin(data[RTC_YEARS_ADDR])
92 + ((data[RTC_HOUR_ADDR]&0x40) ? 100 : 0);
96 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, ¢, M41T11_YEAR_SIZE);
97 if( !(data[RTC_HOUR_ADDR] & 0x80) ){
98 printf( "m41t11 RTC: cann't keep track of years without CEB set\n" );
101 if( (cent & 0x1) != ((data[RTC_HOUR_ADDR]&0x40)>>7) ){
102 /*century flip store off new year*/
104 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, ¢, M41T11_YEAR_SIZE);
106 tmp->tm_year =((int)cent*100)+bcd2bin(data[RTC_YEARS_ADDR]);
109 tmp->tm_wday = bcd2bin (data[RTC_DAY_ADDR] & 0x07);
113 debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
114 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
115 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
120 int rtc_set (struct rtc_time *tmp)
122 uchar data[RTC_REG_CNT];
124 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
125 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
126 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
128 data[RTC_SEC_ADDR] = bin2bcd(tmp->tm_sec) & 0x7F;/*just in case*/
129 data[RTC_MIN_ADDR] = bin2bcd(tmp->tm_min);
130 data[RTC_HOUR_ADDR] = bin2bcd(tmp->tm_hour) & 0x3F;/*handle cent stuff later*/
131 data[RTC_DATE_ADDR] = bin2bcd(tmp->tm_mday) & 0x3F;
132 data[RTC_MONTH_ADDR] = bin2bcd(tmp->tm_mon);
133 data[RTC_DAY_ADDR] = bin2bcd(tmp->tm_wday) & 0x07;
135 data[RTC_HOUR_ADDR] |= 0x80;/*we will always use CEB*/
137 data[RTC_YEARS_ADDR] = bin2bcd(tmp->tm_year%100);/*same thing either way*/
138 #ifndef CONFIG_SYS_M41T11_EXT_CENTURY_DATA
139 if( ((tmp->tm_year - CONFIG_SYS_M41T11_BASE_YEAR) > 200) ||
140 (tmp->tm_year < CONFIG_SYS_M41T11_BASE_YEAR) ){
141 printf( "m41t11 RTC setting year out of range!!need recompile\n" );
143 data[RTC_HOUR_ADDR] |= (tmp->tm_year - CONFIG_SYS_M41T11_BASE_YEAR) > 100 ? 0x40 : 0;
147 cent = tmp->tm_year ? tmp->tm_year / 100 : 0;
148 data[RTC_HOUR_ADDR] |= (cent & 0x1) ? 0x40 : 0;
149 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T11_YEAR_DATA, 1, ¢, M41T11_YEAR_SIZE);
152 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, data, RTC_REG_CNT);
157 void rtc_reset (void)
160 /* clear all control & status registers */
161 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, 1);
162 val = val & 0x7F;/*make sure we are running*/
163 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC_ADDR, 1, &val, RTC_REG_CNT);
165 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);
166 val = val & 0x3F;/*turn off freq test keep calibration*/
167 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_CONTROL_ADDR, 1, &val, 1);