demos/video_usercopy.c

   1 int p20_ioctl(int cmd, void*arg) {
   2   switch(cmd) {
   3   case VIDIOGCTUNER: {
   4     struct video_tuner v;
   5     if(copy_from_user(&v,arg)!=0)
   6       return -EFAULT;
   7     if(v.tuner)
   8       return -EINVAL;
   9     v.rangelow = 87*16000;
  10     v.rangehigh = 108 * 16000;
  11     if(copy_to_user(arg,&v))
  12       return -EFAULT;
  13     return 0;
  14   }
  15   case AGCTUNER: {
  16     struct video_tuner v;
  17     if(copy_from_user(&v,arg))
  18       {
  19         return -EFAULT;
  20       }
  21     if(v.tuner)
  22       return -EINVAL;
  23     v.rangelow = 0;
  24     v.rangehigh = 0;
  25     if(copy_to_user(arg,&v))
  26       return -EFAULT;
  27     return 0;
  28   }
  29   }
  30 }