static const char proc_filename[] = "driver/xxx";

static struct file_operations proc_ops = {
  .open = proc_xxx_open,
  .read = seq_read,
  .llseek = seq_lseek,
  .release = single_release,
};

static void create_proc_file(void)
{
  struct proc_dir_entry *pde;

  pde = create_proc_entry (proc_filename, 0, NULL);
  if (pde)
    pde->proc_fops = &proc_ops;
}