sys/src/9/xen/devrtc.c

   1 /*
   2  * Xen wall clock
   3  */
   4
   5 #include        "u.h"
   6 #include        "../port/lib.h"
   7 #include        "mem.h"
   8 #include        "dat.h"
   9 #include        "fns.h"
  10 #include        "../port/error.h"
  11
  12 enum{
  13         Qdir = 0,
  14         Qrtc,
  15 };
  16
  17 Dirtab rtcdir[]={
  18         ".",    {Qdir, 0, QTDIR},       0,      0555,
  19         "rtc",          {Qrtc, 0},      0,      0664,
  20 };
  21
  22 static long
  23 rtcread(Chan *c, void *a, long n, vlong offset)
  24 {
  25         if(c->qid.type & QTDIR)
  26                 return devdirread(c, a, n, rtcdir, nelem(rtcdir), devgen);
  27
  28         switch((ulong)c->qid.path){
  29         case Qrtc:
  30                 return readnum((ulong)offset, a, n, xenwallclock(), 12);
  31         }
  32         error(Ebadarg);
  33         return 0;
  34 }
  35
  36 static long
  37 rtcwrite(Chan*c, void*, long n, vlong)
  38 {
  39         switch((ulong)c->qid.path){
  40         case Qrtc:
  41                 return n;
  42         }
  43         error(Eperm);
  44         return 0;
  45 }
  46
  47 static Chan*
  48 rtcattach(char* spec)
  49 {
  50         return devattach('r', spec);
  51 }
  52
  53 static Walkqid*
  54 rtcwalk(Chan* c, Chan *nc, char** name, int nname)
  55 {
  56         return devwalk(c, nc, name, nname, rtcdir, nelem(rtcdir), devgen);
  57 }
  58
  59 static int
  60 rtcstat(Chan* c, uchar* dp, int n)
  61 {
  62         return devstat(c, dp, n, rtcdir, nelem(rtcdir), devgen);
  63 }
  64
  65 static Chan*
  66 rtcopen(Chan* c, int omode)
  67 {
  68         return devopen(c, omode, rtcdir, nelem(rtcdir), devgen);
  69 }
  70
  71 static void
  72 rtcclose(Chan*)
  73 {
  74 }
  75
  76 Dev rtcdevtab = {
  77         'r',
  78         "rtc",
  79
  80         devreset,
  81         devinit,
  82         devshutdown,
  83         rtcattach,
  84         rtcwalk,
  85         rtcstat,
  86         rtcopen,
  87         devcreate,
  88         rtcclose,
  89         rtcread,
  90         devbread,
  91         rtcwrite,
  92         devbwrite,
  93         devremove,
  94         devwstat,
  95 };
  96