NSC_COMMAND
outb(NSC_COMMAND_CANCEL, priv->base + NSC_COMMAND);
outb(NSC_COMMAND_NORMAL, priv->base + NSC_COMMAND);
outb(NSC_COMMAND_EOC, priv->base + NSC_COMMAND);
outb(NSC_COMMAND_CANCEL, priv->base + NSC_COMMAND);