1 /* vi: set sw=4 ts=4: */
3 * Mini hwclock implementation for busybox
5 * Copyright (C) 2002 Robert Griebl <griebl@gmx.de>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include <sys/utsname.h>
33 #include <linux/rtc.h>
34 #include <sys/ioctl.h>
37 #ifdef CONFIG_FEATURE_HWCLOCK_LONGOPTIONS
53 time_t read_rtc ( int utc )
60 if (( rtc = open ( "/dev/rtc", O_RDONLY )) < 0 ) {
61 if (( rtc = open ( "/dev/misc/rtc", O_RDONLY )) < 0 )
62 perror_msg_and_die ( "Could not access RTC" );
64 memset ( &tm, 0, sizeof( struct tm ));
65 if ( ioctl ( rtc, RTC_RD_TIME, &tm ) < 0 )
66 perror_msg_and_die ( "Could not read time from RTC" );
67 tm. tm_isdst = -1; // not known
72 oldtz = getenv ( "TZ" );
73 setenv ( "TZ", "UTC 0", 1 );
81 setenv ( "TZ", oldtz, 1 );
89 void write_rtc ( time_t t, int utc )
94 if (( rtc = open ( "/dev/rtc", O_WRONLY )) < 0 ) {
95 if (( rtc = open ( "/dev/misc/rtc", O_WRONLY )) < 0 )
96 perror_msg_and_die ( "Could not access RTC" );
101 tm = *( utc ? gmtime ( &t ) : localtime ( &t ));
106 if ( ioctl ( rtc, RTC_SET_TIME, &tm ) < 0 )
107 perror_msg_and_die ( "Could not set the RTC time" );
112 int show_clock ( int utc )
118 t = read_rtc ( utc );
119 ptm = localtime ( &t ); /* Sets 'tzname[]' */
121 safe_strncpy ( buffer, ctime ( &t ), sizeof( buffer ));
123 buffer [xstrlen ( buffer ) - 1] = 0;
125 //printf ( "%s %.6f seconds %s\n", buffer, 0.0, utc ? "" : ( ptm-> tm_isdst ? tzname [1] : tzname [0] ));
126 printf ( "%s %.6f seconds\n", buffer, 0.0 );
131 int to_sys_clock ( int utc )
133 struct timeval tv = { 0, 0 };
134 const struct timezone tz = { timezone/60 - 60*daylight, 0 };
136 tv. tv_sec = read_rtc ( utc );
138 if ( settimeofday ( &tv, &tz ))
139 perror_msg_and_die ( "settimeofday() failed" );
144 int from_sys_clock ( int utc )
146 struct timeval tv = { 0, 0 };
147 struct timezone tz = { 0, 0 };
149 if ( gettimeofday ( &tv, &tz ))
150 perror_msg_and_die ( "gettimeofday() failed" );
152 write_rtc ( tv. tv_sec, utc );
157 int check_utc ( void )
160 FILE *f = fopen ( "/etc/adjtime", "r" );
165 while ( fgets ( buffer, sizeof( buffer ), f )) {
166 int len = xstrlen ( buffer );
168 while ( len && isspace ( buffer [len - 1] ))
173 if ( strncmp ( buffer, "UTC", 3 ) == 0 ) {
183 extern int hwclock_main ( int argc, char **argv )
186 enum OpMode mode = SHOW;
190 #ifdef CONFIG_FEATURE_HWCLOCK_LONGOPTIONS
191 struct option long_options[] = {
192 { "show", 0, 0, 'r' },
193 { "utc", 0, 0, 'u' },
194 { "localtime", 0, 0, 'l' },
195 { "hctosys", 0, 0, 's' },
196 { "systohc", 0, 0, 'w' },
200 while (( opt = getopt_long ( argc, argv, "rwsul", long_options, 0 )) != EOF ) {
202 while (( opt = getopt ( argc, argv, "rwsul" )) != EOF ) {
218 case 'l': // -l is not supported by the normal hwclock (only --localtime)
233 return from_sys_clock ( utc );
236 return to_sys_clock ( utc );
240 return show_clock ( utc );