1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2002
4 * ARIO Data Networks, Inc. dchiu@ariodata.com
5 *
6 * modified for DS1556:
7 * Frank Panno <fpanno@delphintech.com>, Delphin Technology AG
8 *
9 * Based on MontaVista DS1743 code and U-Boot mc146818 code
10 */
11
12 /*
13 * Date & Time support for the DS1556 RTC
14 */
15
16 /*#define RTC_DEBUG */
17
18 #include <common.h>
19 #include <command.h>
20 #include <rtc.h>
21
22 #if defined(CONFIG_CMD_DATE)
23
24 static uchar rtc_read( unsigned int addr );
25 static void rtc_write( unsigned int addr, uchar val);
26
27 #define RTC_BASE ( CONFIG_SYS_NVRAM_SIZE + CONFIG_SYS_NVRAM_BASE_ADDR )
28
29 #define RTC_YEAR ( RTC_BASE + 0xf )
30 #define RTC_MONTH ( RTC_BASE + 0xe )
31 #define RTC_DAY_OF_MONTH ( RTC_BASE + 0xd )
32 #define RTC_DAY_OF_WEEK ( RTC_BASE + 0xc )
33 #define RTC_HOURS ( RTC_BASE + 0xb )
34 #define RTC_MINUTES ( RTC_BASE + 0xa )
35 #define RTC_SECONDS ( RTC_BASE + 0x9 )
36 #define RTC_CENTURY ( RTC_BASE + 0x8 )
37
38 #define RTC_CONTROLA RTC_CENTURY
39 #define RTC_CONTROLB RTC_SECONDS
40 #define RTC_CONTROLC RTC_BASE
41
42 #define RTC_CA_WRITE 0x80
43 #define RTC_CA_READ 0x40
44
45 #define RTC_CB_OSC_DISABLE 0x80
46
47 #define RTC_CC_BATTERY_FLAG 0x10
48 #define RTC_CC_FREQ_TEST 0x40
49
50 /* ------------------------------------------------------------------------- */
51
rtc_get(struct rtc_time * tmp)52 int rtc_get( struct rtc_time *tmp )
53 {
54 uchar sec, min, hour;
55 uchar mday, wday, mon, year;
56
57 int century;
58
59 uchar reg_a;
60
61 reg_a = rtc_read( RTC_CONTROLA );
62 /* lock clock registers for read */
63 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
64
65 sec = rtc_read( RTC_SECONDS );
66 min = rtc_read( RTC_MINUTES );
67 hour = rtc_read( RTC_HOURS );
68 mday = rtc_read( RTC_DAY_OF_MONTH );
69 wday = rtc_read( RTC_DAY_OF_WEEK );
70 mon = rtc_read( RTC_MONTH );
71 year = rtc_read( RTC_YEAR );
72 century = rtc_read( RTC_CENTURY );
73
74 /* unlock clock registers after read */
75 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
76
77 #ifdef RTC_DEBUG
78 printf( "Get RTC year: %02x mon/cent: %02x mon: %02x mday: %02x wday: %02x "
79 "hr: %02x min: %02x sec: %02x\n",
80 year, century, mon, mday, wday,
81 hour, min, sec );
82 #endif
83 tmp->tm_sec = bcd2bin( sec & 0x7F );
84 tmp->tm_min = bcd2bin( min & 0x7F );
85 tmp->tm_hour = bcd2bin( hour & 0x3F );
86 tmp->tm_mday = bcd2bin( mday & 0x3F );
87 tmp->tm_mon = bcd2bin( mon & 0x1F );
88 tmp->tm_wday = bcd2bin( wday & 0x07 );
89
90 /* glue year from century and year in century */
91 tmp->tm_year = bcd2bin( year ) +
92 ( bcd2bin( century & 0x3F ) * 100 );
93
94 tmp->tm_yday = 0;
95 tmp->tm_isdst= 0;
96 #ifdef RTC_DEBUG
97 printf( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
98 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
99 tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
100 #endif
101 return 0;
102 }
103
rtc_set(struct rtc_time * tmp)104 int rtc_set( struct rtc_time *tmp )
105 {
106 uchar reg_a;
107 #ifdef RTC_DEBUG
108 printf( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
109 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
110 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
111 #endif
112 /* lock clock registers for write */
113 reg_a = rtc_read( RTC_CONTROLA );
114 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
115
116 rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
117
118 rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday ));
119 rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday ));
120 rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour ));
121 rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min ));
122 rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec ));
123
124 /* break year up into century and year in century */
125 rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
126 rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 ));
127
128 /* unlock clock registers after read */
129 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_WRITE ));
130
131 return 0;
132 }
133
rtc_reset(void)134 void rtc_reset (void)
135 {
136 uchar reg_a, reg_b, reg_c;
137
138 reg_a = rtc_read( RTC_CONTROLA );
139 reg_b = rtc_read( RTC_CONTROLB );
140
141 if ( reg_b & RTC_CB_OSC_DISABLE )
142 {
143 printf( "real-time-clock was stopped. Now starting...\n" );
144 reg_a |= RTC_CA_WRITE;
145 reg_b &= ~RTC_CB_OSC_DISABLE;
146
147 rtc_write( RTC_CONTROLA, reg_a );
148 rtc_write( RTC_CONTROLB, reg_b );
149 }
150
151 /* make sure read/write clock register bits are cleared */
152 reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
153 rtc_write( RTC_CONTROLA, reg_a );
154
155 reg_c = rtc_read( RTC_CONTROLC );
156 if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 )
157 printf( "RTC battery low. Clock setting may not be reliable.\n" );
158 }
159
160 /* ------------------------------------------------------------------------- */
161
rtc_read(unsigned int addr)162 static uchar rtc_read( unsigned int addr )
163 {
164 uchar val = *(volatile unsigned char*)(addr);
165 #ifdef RTC_DEBUG
166 printf( "rtc_read: %x:%x\n", addr, val );
167 #endif
168 return( val );
169 }
170
rtc_write(unsigned int addr,uchar val)171 static void rtc_write( unsigned int addr, uchar val )
172 {
173 #ifdef RTC_DEBUG
174 printf( "rtc_write: %x:%x\n", addr, val );
175 #endif
176 *(volatile unsigned char*)(addr) = val;
177 }
178
179 #endif
180