4 * Phantom RTC device driver for EVA
9 * Copyright 2002 Etinsys Inc.
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the
13 * Free Software Foundation; either version 2 of the License, or (at your
14 * option) any later version.
21 #if defined(CONFIG_CMD_DATE)
23 #define RTC_BASE (CONFIG_SYS_NVRAM_BASE_ADDR + 0x7fff8)
25 #define RTC_YEAR ( RTC_BASE + 7 )
26 #define RTC_MONTH ( RTC_BASE + 6 )
27 #define RTC_DAY_OF_MONTH ( RTC_BASE + 5 )
28 #define RTC_DAY_OF_WEEK ( RTC_BASE + 4 )
29 #define RTC_HOURS ( RTC_BASE + 3 )
30 #define RTC_MINUTES ( RTC_BASE + 2 )
31 #define RTC_SECONDS ( RTC_BASE + 1 )
32 #define RTC_CENTURY ( RTC_BASE + 0 )
34 #define RTC_CONTROLA RTC_CENTURY
35 #define RTC_CONTROLB RTC_SECONDS
36 #define RTC_CONTROLC RTC_DAY_OF_WEEK
38 #define RTC_CA_WRITE 0x80
39 #define RTC_CA_READ 0x40
41 #define RTC_CB_OSC_DISABLE 0x80
43 #define RTC_CC_BATTERY_FLAG 0x80
44 #define RTC_CC_FREQ_TEST 0x40
47 static int phantom_flag = -1;
48 static int century_flag = -1;
50 static uchar rtc_read(unsigned int addr)
52 return *(volatile unsigned char *)(addr);
55 static void rtc_write(unsigned int addr, uchar val)
57 *(volatile unsigned char *)(addr) = val;
60 static unsigned char phantom_rtc_sequence[] = {
61 0xc5, 0x3a, 0xa3, 0x5c, 0xc5, 0x3a, 0xa3, 0x5c
64 static unsigned char* phantom_rtc_read(int addr, unsigned char rtc[8])
68 unsigned char save = rtc_read(addr);
70 for (j = 0; j < 8; j++) {
71 v = phantom_rtc_sequence[j];
72 for (i = 0; i < 8; i++) {
73 rtc_write(addr, v & 1);
77 for (j = 0; j < 8; j++) {
79 for (i = 0; i < 8; i++) {
80 if(rtc_read(addr) & 1)
85 rtc_write(addr, save);
89 static void phantom_rtc_write(int addr, unsigned char rtc[8])
93 unsigned char save = rtc_read(addr);
94 for (j = 0; j < 8; j++) {
95 v = phantom_rtc_sequence[j];
96 for (i = 0; i < 8; i++) {
97 rtc_write(addr, v & 1);
101 for (j = 0; j < 8; j++) {
103 for (i = 0; i < 8; i++) {
104 rtc_write(addr, v & 1);
108 rtc_write(addr, save);
111 static int get_phantom_flag(void)
114 unsigned char rtc[8];
116 phantom_rtc_read(RTC_BASE, rtc);
118 for(i = 1; i < 8; i++) {
119 if (rtc[i] != rtc[0])
127 if (phantom_flag < 0)
128 phantom_flag = get_phantom_flag();
131 unsigned char rtc[8];
132 phantom_rtc_read(RTC_BASE, rtc);
134 printf( "real-time-clock was stopped. Now starting...\n" );
136 phantom_rtc_write(RTC_BASE, rtc);
139 uchar reg_a, reg_b, reg_c;
140 reg_a = rtc_read( RTC_CONTROLA );
141 reg_b = rtc_read( RTC_CONTROLB );
143 if ( reg_b & RTC_CB_OSC_DISABLE )
145 printf( "real-time-clock was stopped. Now starting...\n" );
146 reg_a |= RTC_CA_WRITE;
147 reg_b &= ~RTC_CB_OSC_DISABLE;
148 rtc_write( RTC_CONTROLA, reg_a );
149 rtc_write( RTC_CONTROLB, reg_b );
152 /* make sure read/write clock register bits are cleared */
153 reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
154 rtc_write( RTC_CONTROLA, reg_a );
156 reg_c = rtc_read( RTC_CONTROLC );
157 if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 )
158 printf( "RTC battery low. Clock setting may not be reliable.\n");
162 inline unsigned bcd2bin (uchar n)
164 return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
167 inline unsigned char bin2bcd (unsigned int n)
169 return (((n / 10) << 4) | (n % 10));
172 static int get_century_flag(void)
176 bcd = rtc_read( RTC_CENTURY );
177 century = bcd2bin( bcd & 0x3F );
178 rtc_write( RTC_CENTURY, bin2bcd(century+1));
179 if (bcd == rtc_read( RTC_CENTURY ))
181 rtc_write( RTC_CENTURY, bcd);
185 int rtc_get( struct rtc_time *tmp)
187 if (phantom_flag < 0)
188 phantom_flag = get_phantom_flag();
192 unsigned char rtc[8];
194 phantom_rtc_read(RTC_BASE, rtc);
196 tmp->tm_sec = bcd2bin(rtc[1] & 0x7f);
197 tmp->tm_min = bcd2bin(rtc[2] & 0x7f);
198 tmp->tm_hour = bcd2bin(rtc[3] & 0x1f);
199 tmp->tm_wday = bcd2bin(rtc[4] & 0x7);
200 tmp->tm_mday = bcd2bin(rtc[5] & 0x3f);
201 tmp->tm_mon = bcd2bin(rtc[6] & 0x1f);
202 tmp->tm_year = bcd2bin(rtc[7]) + 1900;
206 if( (rtc[3] & 0x80) && (rtc[3] & 0x40) ) tmp->tm_hour += 12;
207 if (tmp->tm_year < 1970) tmp->tm_year += 100;
209 uchar sec, min, hour;
210 uchar mday, wday, mon, year;
216 if (century_flag < 0)
217 century_flag = get_century_flag();
219 reg_a = rtc_read( RTC_CONTROLA );
220 /* lock clock registers for read */
221 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
223 sec = rtc_read( RTC_SECONDS );
224 min = rtc_read( RTC_MINUTES );
225 hour = rtc_read( RTC_HOURS );
226 mday = rtc_read( RTC_DAY_OF_MONTH );
227 wday = rtc_read( RTC_DAY_OF_WEEK );
228 mon = rtc_read( RTC_MONTH );
229 year = rtc_read( RTC_YEAR );
230 century = rtc_read( RTC_CENTURY );
232 /* unlock clock registers after read */
233 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
235 tmp->tm_sec = bcd2bin( sec & 0x7F );
236 tmp->tm_min = bcd2bin( min & 0x7F );
237 tmp->tm_hour = bcd2bin( hour & 0x3F );
238 tmp->tm_mday = bcd2bin( mday & 0x3F );
239 tmp->tm_mon = bcd2bin( mon & 0x1F );
240 tmp->tm_wday = bcd2bin( wday & 0x07 );
243 tmp->tm_year = bcd2bin( year ) +
244 ( bcd2bin( century & 0x3F ) * 100 );
246 tmp->tm_year = bcd2bin( year ) + 1900;
247 if (tmp->tm_year < 1970) tmp->tm_year += 100;
257 int rtc_set( struct rtc_time *tmp )
259 if (phantom_flag < 0)
260 phantom_flag = get_phantom_flag();
264 unsigned char rtc[8];
267 year -= (year < 2000) ? 1900 : 2000;
270 rtc[1] = bin2bcd(tmp->tm_sec);
271 rtc[2] = bin2bcd(tmp->tm_min);
272 rtc[3] = bin2bcd(tmp->tm_hour);
273 rtc[4] = bin2bcd(tmp->tm_wday);
274 rtc[5] = bin2bcd(tmp->tm_mday);
275 rtc[6] = bin2bcd(tmp->tm_mon);
276 rtc[7] = bin2bcd(year);
278 phantom_rtc_write(RTC_BASE, rtc);
281 if (century_flag < 0)
282 century_flag = get_century_flag();
284 /* lock clock registers for write */
285 reg_a = rtc_read( RTC_CONTROLA );
286 rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
288 rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
290 rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday ));
291 rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday ));
292 rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour ));
293 rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min ));
294 rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec ));
296 /* break year up into century and year in century */
298 rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
299 rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 ));
301 reg_a |= bin2bcd( tmp->tm_year / 100 );
303 rtc_write(RTC_YEAR, bin2bcd(tmp->tm_year -
304 ((tmp->tm_year < 2000) ? 1900 : 2000)));
307 /* unlock clock registers after read */
308 rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_WRITE ));