3 * ARIO Data Networks, Inc. dchiu@ariodata.com
5 * Based on MontaVista DS1743 code and U-Boot mc146818 code
7 * SPDX-License-Identifier: GPL-2.0+
11 * Date & Time support for the DS174x RTC
20 #if defined(CONFIG_CMD_DATE)
22 static uchar rtc_read( unsigned int addr );
23 static void rtc_write( unsigned int addr, uchar val);
25 #define RTC_BASE ( CONFIG_SYS_NVRAM_SIZE + CONFIG_SYS_NVRAM_BASE_ADDR )
27 #define RTC_YEAR ( RTC_BASE + 7 )
28 #define RTC_MONTH ( RTC_BASE + 6 )
29 #define RTC_DAY_OF_MONTH ( RTC_BASE + 5 )
30 #define RTC_DAY_OF_WEEK ( RTC_BASE + 4 )
31 #define RTC_HOURS ( RTC_BASE + 3 )
32 #define RTC_MINUTES ( RTC_BASE + 2 )
33 #define RTC_SECONDS ( RTC_BASE + 1 )
34 #define RTC_CENTURY ( RTC_BASE + 0 )
36 #define RTC_CONTROLA RTC_CENTURY
37 #define RTC_CONTROLB RTC_SECONDS
38 #define RTC_CONTROLC RTC_DAY_OF_WEEK
40 #define RTC_CA_WRITE 0x80
41 #define RTC_CA_READ 0x40
43 #define RTC_CB_OSC_DISABLE 0x80
45 #define RTC_CC_BATTERY_FLAG 0x80
46 #define RTC_CC_FREQ_TEST 0x40
48 /* ------------------------------------------------------------------------- */
50 int rtc_get( struct rtc_time *tmp )
53 uchar mday, wday, mon, year;
59 reg_a = rtc_read( RTC_CONTROLA );
60 /* lock clock registers for read */
61 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
63 sec = rtc_read( RTC_SECONDS );
64 min = rtc_read( RTC_MINUTES );
65 hour = rtc_read( RTC_HOURS );
66 mday = rtc_read( RTC_DAY_OF_MONTH );
67 wday = rtc_read( RTC_DAY_OF_WEEK );
68 mon = rtc_read( RTC_MONTH );
69 year = rtc_read( RTC_YEAR );
70 century = rtc_read( RTC_CENTURY );
72 /* unlock clock registers after read */
73 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
76 printf( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
77 "hr: %02x min: %02x sec: %02x\n",
78 year, mon_cent, mday, wday,
81 tmp->tm_sec = bcd2bin( sec & 0x7F );
82 tmp->tm_min = bcd2bin( min & 0x7F );
83 tmp->tm_hour = bcd2bin( hour & 0x3F );
84 tmp->tm_mday = bcd2bin( mday & 0x3F );
85 tmp->tm_mon = bcd2bin( mon & 0x1F );
86 tmp->tm_wday = bcd2bin( wday & 0x07 );
88 /* glue year from century and year in century */
89 tmp->tm_year = bcd2bin( year ) +
90 ( bcd2bin( century & 0x3F ) * 100 );
95 printf( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
96 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
97 tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
102 int rtc_set( struct rtc_time *tmp )
106 printf( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
107 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
108 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
110 /* lock clock registers for write */
111 reg_a = rtc_read( RTC_CONTROLA );
112 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
114 rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
116 rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday ));
117 rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday ));
118 rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour ));
119 rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min ));
120 rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec ));
122 /* break year up into century and year in century */
123 rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
124 rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 ));
126 /* unlock clock registers after read */
127 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_WRITE ));
132 void rtc_reset (void)
134 uchar reg_a, reg_b, reg_c;
136 reg_a = rtc_read( RTC_CONTROLA );
137 reg_b = rtc_read( RTC_CONTROLB );
139 if ( reg_b & RTC_CB_OSC_DISABLE )
141 printf( "real-time-clock was stopped. Now starting...\n" );
142 reg_a |= RTC_CA_WRITE;
143 reg_b &= ~RTC_CB_OSC_DISABLE;
145 rtc_write( RTC_CONTROLA, reg_a );
146 rtc_write( RTC_CONTROLB, reg_b );
149 /* make sure read/write clock register bits are cleared */
150 reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
151 rtc_write( RTC_CONTROLA, reg_a );
153 reg_c = rtc_read( RTC_CONTROLC );
154 if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 )
155 printf( "RTC battery low. Clock setting may not be reliable.\n" );
158 /* ------------------------------------------------------------------------- */
160 static uchar rtc_read( unsigned int addr )
162 uchar val = in8( addr );
164 printf( "rtc_read: %x:%x\n", addr, val );
169 static void rtc_write( unsigned int addr, uchar val )
172 printf( "rtc_write: %x:%x\n", addr, val );