1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2002
4 * ARIO Data Networks, Inc. dchiu@ariodata.com
5 *
6 * modified for DS164x:
7 * The LEOX team <team@leox.org>, http://www.leox.org
8 *
9 * Based on MontaVista DS1743 code and U-Boot mc146818 code
10 */
11
12 /*
13 * Date & Time support for the DS164x RTC
14 */
15
16 /* #define RTC_DEBUG */
17
18 #include <common.h>
19 #include <command.h>
20 #include <rtc.h>
21
22
23 static uchar rtc_read(unsigned int addr );
24 static void rtc_write(unsigned int addr, uchar val);
25
26 #define RTC_EPOCH 2000 /* century */
27
28 /*
29 * DS164x registers layout
30 */
31 #define RTC_BASE ( CONFIG_SYS_NVRAM_BASE_ADDR + CONFIG_SYS_NVRAM_SIZE )
32
33 #define RTC_YEAR ( RTC_BASE + 0x07 )
34 #define RTC_MONTH ( RTC_BASE + 0x06 )
35 #define RTC_DAY_OF_MONTH ( RTC_BASE + 0x05 )
36 #define RTC_DAY_OF_WEEK ( RTC_BASE + 0x04 )
37 #define RTC_HOURS ( RTC_BASE + 0x03 )
38 #define RTC_MINUTES ( RTC_BASE + 0x02 )
39 #define RTC_SECONDS ( RTC_BASE + 0x01 )
40 #define RTC_CONTROL ( RTC_BASE + 0x00 )
41
42 #define RTC_CONTROLA RTC_CONTROL /* W=bit6, R=bit5 */
43 #define RTC_CA_WRITE 0x80
44 #define RTC_CA_READ 0x40
45 #define RTC_CONTROLB RTC_SECONDS /* OSC=bit7 */
46 #define RTC_CB_OSC_DISABLE 0x80
47 #define RTC_CONTROLC RTC_DAY_OF_WEEK /* FT=bit6 */
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 uchar reg_a;
58
59 reg_a = rtc_read( RTC_CONTROLA );
60 /* lock clock registers for read */
61 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
62
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
71 /* unlock clock registers after read */
72 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
73
74 #ifdef RTC_DEBUG
75 printf( "Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
76 "hr: %02x min: %02x sec: %02x\n",
77 year, mon, mday, wday,
78 hour, min, sec );
79 #endif
80 tmp->tm_sec = bcd2bin( sec & 0x7F );
81 tmp->tm_min = bcd2bin( min & 0x7F );
82 tmp->tm_hour = bcd2bin( hour & 0x3F );
83 tmp->tm_mday = bcd2bin( mday & 0x3F );
84 tmp->tm_mon = bcd2bin( mon & 0x1F );
85 tmp->tm_wday = bcd2bin( wday & 0x07 );
86
87 /* glue year in century (2000) */
88 tmp->tm_year = bcd2bin( year ) + RTC_EPOCH;
89
90 tmp->tm_yday = 0;
91 tmp->tm_isdst= 0;
92 #ifdef RTC_DEBUG
93 printf( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
94 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
95 tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
96 #endif
97
98 return 0;
99 }
100
rtc_set(struct rtc_time * tmp)101 int rtc_set( struct rtc_time *tmp )
102 {
103 uchar reg_a;
104
105 #ifdef RTC_DEBUG
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);
109 #endif
110 /* lock clock registers for write */
111 reg_a = rtc_read( RTC_CONTROLA );
112 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
113
114 rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
115
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 ));
121
122 /* break year in century */
123 rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
124
125 /* unlock clock registers after read */
126 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_WRITE ));
127
128 return 0;
129 }
130
rtc_reset(void)131 void rtc_reset (void)
132 {
133 uchar reg_a, reg_b;
134
135 reg_a = rtc_read( RTC_CONTROLA );
136 reg_b = rtc_read( RTC_CONTROLB );
137
138 if ( reg_b & RTC_CB_OSC_DISABLE )
139 {
140 printf( "real-time-clock was stopped. Now starting...\n" );
141 reg_a |= RTC_CA_WRITE;
142 reg_b &= ~RTC_CB_OSC_DISABLE;
143
144 rtc_write( RTC_CONTROLA, reg_a );
145 rtc_write( RTC_CONTROLB, reg_b );
146 }
147
148 /* make sure read/write clock register bits are cleared */
149 reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
150 rtc_write( RTC_CONTROLA, reg_a );
151 }
152
153 /* ------------------------------------------------------------------------- */
154
rtc_read(unsigned int addr)155 static uchar rtc_read( unsigned int addr )
156 {
157 uchar val = *(volatile unsigned char*)(addr);
158
159 #ifdef RTC_DEBUG
160 printf( "rtc_read: %x:%x\n", addr, val );
161 #endif
162 return( val );
163 }
164
rtc_write(unsigned int addr,uchar val)165 static void rtc_write( unsigned int addr, uchar val )
166 {
167 #ifdef RTC_DEBUG
168 printf( "rtc_write: %x:%x\n", addr, val );
169 #endif
170 *(volatile unsigned char*)(addr) = val;
171 }
172