return 0;
 }
 
-static struct snd_pcm_ops snd_ad1816a_playback_ops = {
+static const struct snd_pcm_ops snd_ad1816a_playback_ops = {
        .open =         snd_ad1816a_playback_open,
        .close =        snd_ad1816a_playback_close,
        .ioctl =        snd_pcm_lib_ioctl,
        .pointer =      snd_ad1816a_playback_pointer,
 };
 
-static struct snd_pcm_ops snd_ad1816a_capture_ops = {
+static const struct snd_pcm_ops snd_ad1816a_capture_ops = {
        .open =         snd_ad1816a_capture_open,
        .close =        snd_ad1816a_capture_close,
        .ioctl =        snd_pcm_lib_ioctl,