return snd_es18xx_initialize(chip, mpu_port, fm_port);
 }
 
-static struct snd_pcm_ops snd_es18xx_playback_ops = {
+static const struct snd_pcm_ops snd_es18xx_playback_ops = {
        .open =         snd_es18xx_playback_open,
        .close =        snd_es18xx_playback_close,
        .ioctl =        snd_pcm_lib_ioctl,
        .pointer =      snd_es18xx_playback_pointer,
 };
 
-static struct snd_pcm_ops snd_es18xx_capture_ops = {
+static const struct snd_pcm_ops snd_es18xx_capture_ops = {
        .open =         snd_es18xx_capture_open,
        .close =        snd_es18xx_capture_close,
        .ioctl =        snd_pcm_lib_ioctl,