-static void interrupt_wave(snd_gus_card_t *gus, snd_gus_voice_t *voice);
-static void interrupt_volume(snd_gus_card_t *gus, snd_gus_voice_t *voice);
-static void interrupt_effect(snd_gus_card_t *gus, snd_gus_voice_t *voice);
-
-static void sample_start(snd_gus_card_t *gus, snd_gus_voice_t *voice, snd_seq_position_t position);
-static void sample_stop(snd_gus_card_t *gus, snd_gus_voice_t *voice, snd_seq_stop_mode_t mode);
-static void sample_freq(snd_gus_card_t *gus, snd_gus_voice_t *voice, snd_seq_frequency_t freq);
-static void sample_volume(snd_gus_card_t *card, snd_gus_voice_t *voice, snd_seq_ev_volume_t *volume);
-static void sample_loop(snd_gus_card_t *card, snd_gus_voice_t *voice, snd_seq_ev_loop_t *loop);
-static void sample_pos(snd_gus_card_t *card, snd_gus_voice_t *voice, snd_seq_position_t position);
-static void sample_private1(snd_gus_card_t *card, snd_gus_voice_t *voice, unsigned char *data);
-
-static snd_gus_sample_ops_t sample_ops = {
+static void interrupt_wave(struct snd_gus_card *gus, struct snd_gus_voice *voice);
+static void interrupt_volume(struct snd_gus_card *gus, struct snd_gus_voice *voice);
+static void interrupt_effect(struct snd_gus_card *gus, struct snd_gus_voice *voice);
+
+static void sample_start(struct snd_gus_card *gus, struct snd_gus_voice *voice, snd_seq_position_t position);
+static void sample_stop(struct snd_gus_card *gus, struct snd_gus_voice *voice, int mode);
+static void sample_freq(struct snd_gus_card *gus, struct snd_gus_voice *voice, snd_seq_frequency_t freq);
+static void sample_volume(struct snd_gus_card *card, struct snd_gus_voice *voice, struct snd_seq_ev_volume *volume);
+static void sample_loop(struct snd_gus_card *card, struct snd_gus_voice *voice, struct snd_seq_ev_loop *loop);
+static void sample_pos(struct snd_gus_card *card, struct snd_gus_voice *voice, snd_seq_position_t position);
+static void sample_private1(struct snd_gus_card *card, struct snd_gus_voice *voice, unsigned char *data);
+
+static struct snd_gus_sample_ops sample_ops = {