1 files changed, 105 insertions, 1 deletions
diff --git a/midi.c b/midi.c
index c817bd2..a59ebeb 100644
--- a/midi.c
+++ b/midi.c
@@ -1,3 +1,107 @@
-int midi_start(){
+#include <string.h>
+#include <alsa/asoundlib.h>
+#include "midi.h"
+
+#define BACKEND_NAME "midi"
+static snd_seq_t* sequencer = NULL;
+
+int midi_init(){
+	backend midi = {
+		.name = BACKEND_NAME,
+		.conf = midi_configure,
+		.create = midi_instance,
+		.conf_instance = midi_configure_instance,
+		.channel = midi_channel,
+		.handle = midi_set,
+		.process = midi_handle,
+		.shutdown = midi_shutdown
+	};
+
+	if(snd_seq_open(&sequencer, "default", SND_SEQ_OPEN_DUPLEX, 0) < 0){
+		fprintf(stderr, "Failed to open ALSA sequencer\n");
+		return 1;
+	}
+
+	//register backend
+	if(mm_backend_register(midi)){
+		fprintf(stderr, "Failed to register MIDI backend\n");
+		return 1;
+	}
+	return 0;
+}
+
+static int midi_configure(char* option, char* value){
+	if(!strcmp(option, "name")){
+		if(snd_seq_set_client_name(sequencer, value) < 0){
+			fprintf(stderr, "Failed to set MIDI client name to %s\n", value);
+			return 1;
+		}
+		return 0;
+	}
+
+	fprintf(stderr, "Unknown MIDI backend option %s\n", option);
+	return 1;
+}
+
+static instance* midi_instance(){
+	return mm_instance();
+}
+
+static int midi_configure_instance(instance* instance, char* option, char* value){
+	if(!strcmp(option, "device")){
+		//open i/o device
+		return 0;
+	}
+	else if(!strcmp(option, "port")){
+		//create midi port
+		return 0;
+	}
+	else if(!strcmp(option, "mode")){
+		//configure open mode
+		//FIXME needed?
+		return 0;
+	}
+	
+	fprintf(stderr, "Unknown MIDI instance option %s\n", option);
+	return 1;
+}
+
+static channel* midi_channel(instance* instance, char* spec){
+	fprintf(stderr, "Parsing MIDI channelspec %s\n", spec);
+	//TODO
+	return NULL;
+}
+
+static int midi_set(size_t num, channel* c, channel_value* v){
+	//TODO
 	return 1;
 }
+
+static int midi_handle(size_t num, int* fd, void** data){
+	//TODO
+	return 1;
+}
+
+static int midi_shutdown(){
+	size_t n, p;
+	instance** inst = NULL;
+	if(mm_backend_instances(BACKEND_NAME, &n, &inst)){
+		fprintf(stderr, "Failed to fetch instance list\n");
+		return 1;
+	}
+
+	for(p = 0; p < n; p++){
+		free(inst[p]->impl);
+	}
+	free(inst);
+
+	//close midi
+	snd_seq_close(sequencer);
+	sequencer = NULL;
+
+	//free configuration cache
+	snd_config_update_free_global();
+
+	fprintf(stderr, "MIDI backend shut down\n");
+	return 0;
+}