hwclock/kd.c

   1 /* kd.c - KDGHWCLK stuff, possibly m68k only */
   2 #include <unistd.h>             /* for close() */
   3 #include <fcntl.h>              /* for O_RDONLY */
   4 #include <sys/ioctl.h>
   5
   6 #include "../defines.h"         /* for HAVE_nanosleep */
   7 #include "clock.h"
   8 #include "nls.h"
   9
  10 static int con_fd = -1;         /* opened by probe_for_kd_clock() */
  11                                 /* never closed */
  12
  13 /* Get defines for KDGHWCLK and KDSHWCLK (m68k) */
  14 #include <linux/kd.h>
  15 #ifndef KDGHWCLK
  16 #define KDGHWCLK        0x4B50     /* get hardware clock */
  17 #define KDSHWCLK        0x4B51     /* set hardware clock */
  18 struct hwclk_time {
  19         unsigned        sec;    /* 0..59 */
  20         unsigned        min;    /* 0..59 */
  21         unsigned        hour;   /* 0..23 */
  22         unsigned        day;    /* 1..31 */
  23         unsigned        mon;    /* 0..11 */
  24         unsigned        year;   /* 70... */
  25         int             wday;   /* 0..6, 0 is Sunday, -1 means unknown/don't set */
  26 };
  27 #endif
  28
  29 static int
  30 synchronize_to_clock_tick_kd(void) {
  31 /*----------------------------------------------------------------------------
  32    Wait for the top of a clock tick by calling KDGHWCLK in a busy loop until
  33    we see it.
  34 -----------------------------------------------------------------------------*/
  35   int i;
  36
  37   /* The time when we were called (and started waiting) */
  38   struct hwclk_time start_time, nowtime;
  39
  40   if (debug)
  41     printf(_("Waiting in loop for time from KDGHWCLK to change\n"));
  42
  43   if (ioctl(con_fd, KDGHWCLK, &start_time) == -1) {
  44     outsyserr(_("KDGHWCLK ioctl to read time failed"));
  45     return 3;
  46   }
  47
  48   i = 0;
  49   do {
  50     /* Added by Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> */
  51     /* "The culprit is the fast loop with KDGHWCLK ioctls. It seems
  52        the kernel gets confused by those on Amigas with A2000 RTCs
  53        and simply hangs after some time. Inserting a nanosleep helps." */
  54     /* Christian T. Steigies: 1 instead of 1000000 is still sufficient
  55        to keep the machine from freezing. */
  56
  57 #ifdef HAVE_nanosleep
  58     struct timespec xsleep = { 0, 1 };
  59     nanosleep( &xsleep, NULL );
  60 #else
  61     usleep(1);
  62 #endif
  63
  64     if (i++ >= 1000000) {
  65       fprintf(stderr, _("Timed out waiting for time change.\n"));
  66       return 2;
  67     }
  68     if (ioctl(con_fd, KDGHWCLK, &nowtime) == -1) {
  69       outsyserr(_("KDGHWCLK ioctl to read time failed in loop"));
  70       return 3;
  71     }
  72   } while (start_time.sec == nowtime.sec);
  73
  74   return 0;
  75 }
  76
  77
  78 static int
  79 read_hardware_clock_kd(struct tm *tm) {
  80 /*----------------------------------------------------------------------------
  81   Read the hardware clock and return the current time via <tm>
  82   argument.  Use ioctls to /dev/tty1 on what we assume is an m68k
  83   machine.
  84
  85   Note that we don't use /dev/console here.  That might be a serial
  86   console.
  87 -----------------------------------------------------------------------------*/
  88   struct hwclk_time t;
  89
  90   if (ioctl(con_fd, KDGHWCLK, &t) == -1) {
  91     outsyserr(_("ioctl() failed to read time from  /dev/tty1"));
  92     exit(5);
  93   }
  94
  95   tm->tm_sec  = t.sec;
  96   tm->tm_min  = t.min;
  97   tm->tm_hour = t.hour;
  98   tm->tm_mday = t.day;
  99   tm->tm_mon  = t.mon;
 100   tm->tm_year = t.year;
 101   tm->tm_wday = t.wday;
 102   tm->tm_isdst = -1;     /* Don't know if it's Daylight Savings Time */
 103
 104   return 0;
 105 }
 106
 107
 108 static int
 109 set_hardware_clock_kd(const struct tm *new_broken_time) {
 110 /*----------------------------------------------------------------------------
 111   Set the Hardware Clock to the time <new_broken_time>.  Use ioctls to
 112   /dev/tty1 on what we assume is an m68k machine.
 113
 114   Note that we don't use /dev/console here.  That might be a serial console.
 115 ----------------------------------------------------------------------------*/
 116   struct hwclk_time t;
 117
 118   t.sec  = new_broken_time->tm_sec;
 119   t.min  = new_broken_time->tm_min;
 120   t.hour = new_broken_time->tm_hour;
 121   t.day  = new_broken_time->tm_mday;
 122   t.mon  = new_broken_time->tm_mon;
 123   t.year = new_broken_time->tm_year;
 124   t.wday = new_broken_time->tm_wday;
 125
 126   if (ioctl(con_fd, KDSHWCLK, &t ) == -1) {
 127     outsyserr(_("ioctl() to open /dev/tty1 failed"));
 128     exit(1);
 129   }
 130   return 0;
 131 }
 132
 133 static int
 134 get_permissions_kd(void) {
 135   return 0;
 136 }
 137
 138 static struct clock_ops kd = {
 139         "KDGHWCLK interface to m68k clock",
 140         get_permissions_kd,
 141         read_hardware_clock_kd,
 142         set_hardware_clock_kd,
 143         synchronize_to_clock_tick_kd,
 144 };
 145
 146 /* return &kd if KDGHWCLK works, NULL otherwise */
 147 struct clock_ops *
 148 probe_for_kd_clock() {
 149     struct clock_ops *ret = NULL;
 150     struct hwclk_time t;
 151
 152     if (con_fd < 0)
 153       con_fd = open("/dev/tty1", O_RDONLY);
 154     if (con_fd >= 0) {
 155       if (ioctl( con_fd, KDGHWCLK, &t ) == -1) {
 156         if (errno != EINVAL)
 157          outsyserr(_("KDGHWCLK ioctl failed"));
 158       } else
 159         ret = &kd;
 160     } else {
 161       /* probably KDGHWCLK exists on m68k only */
 162 #ifdef __m68k__
 163       outsyserr(_("Can't open /dev/tty1"));
 164 #endif
 165     }
 166     return ret;
 167 }