return bytes_to_frames(ss->runtime, ptr);
 }
 
-static struct snd_pcm_ops snd_ad1889_playback_ops = {
+static const struct snd_pcm_ops snd_ad1889_playback_ops = {
        .open = snd_ad1889_playback_open,
        .close = snd_ad1889_playback_close,
        .ioctl = snd_pcm_lib_ioctl,
        .pointer = snd_ad1889_playback_pointer, 
 };
 
-static struct snd_pcm_ops snd_ad1889_capture_ops = {
+static const struct snd_pcm_ops snd_ad1889_capture_ops = {
        .open = snd_ad1889_capture_open,
        .close = snd_ad1889_capture_close,
        .ioctl = snd_pcm_lib_ioctl,