Added Linux MIDI output via ALSA.

src/midi_alsa.c

@@ -0,0 +1,184 @@
+#include <alsa/asoundlib.h>
+#include "ibm.h"
+#include "config.h"
+#include "plat-midi.h"
+
+#define MAX_MIDI_DEVICES 128
+
+static struct
+{
+	int card;
+	int device;
+	int sub;
+	char name[50];
+} midi_devices[MAX_MIDI_DEVICES];
+
+static int midi_device_count = 0;
+
+static int midi_queried = 0;
+
+static snd_rawmidi_t *midiout = NULL;
+
+static void midi_query()
+{
+	int status;
+	int card = -1;
+
+	midi_queried = 1;
+
+	if ((status = snd_card_next(&card)) < 0)
+		return;
+
+	if (card < 0)
+		return; /*No cards*/
+
+	while (card >= 0)
+	{
+		char *shortname;
+
+		if ((status = snd_card_get_name(card, &shortname)) >= 0)
+		{
+			snd_ctl_t *ctl;
+			char name[32];
+
+			sprintf(name, "hw:%i", card);
+
+			if ((status = snd_ctl_open(&ctl, name, 0)) >= 0)
+			{
+				int device = -1;
+
+				do
+				{
+					status = snd_ctl_rawmidi_next_device(ctl, &device);
+					if (status >= 0 && device != -1)
+					{
+						snd_rawmidi_info_t *info;
+						int sub_nr, sub;
+
+						snd_rawmidi_info_alloca(&info);
+						snd_rawmidi_info_set_device(info, device);
+						snd_rawmidi_info_set_stream(info, SND_RAWMIDI_STREAM_OUTPUT);
+						snd_ctl_rawmidi_info(ctl, info);
+						sub_nr = snd_rawmidi_info_get_subdevices_count(info);
+						pclog("sub_nr=%i\n",sub_nr);
+
+						for (sub = 0; sub < sub_nr; sub++)
+						{
+							snd_rawmidi_info_set_subdevice(info, sub);
+
+							if (snd_ctl_rawmidi_info(ctl, info) == 0)
+							{
+								pclog("%s: MIDI device=%i:%i:%i\n", shortname, card, device,sub);
+
+								midi_devices[midi_device_count].card = card;
+								midi_devices[midi_device_count].device = device;
+								midi_devices[midi_device_count].sub = sub;
+								snprintf(midi_devices[midi_device_count].name, 50, "%s (%i:%i:%i)", shortname, card, device, sub);
+								midi_device_count++;
+								if (midi_device_count >= MAX_MIDI_DEVICES)
+									return;
+							}
+						}
+					}
+				} while (device >= 0);
+			}
+		}
+
+		if (snd_card_next(&card) < 0)
+			break;
+	}
+}
+
+void midi_init()
+{
+	char portname[32];
+	int midi_id;
+
+	if (!midi_queried)
+		midi_query();
+
+	midi_id = config_get_int(CFG_MACHINE, NULL, "midi", 0);
+
+	sprintf(portname, "hw:%i,%i,%i", midi_devices[midi_id].card,
+					 midi_devices[midi_id].device,
+					 midi_devices[midi_id].sub);
+	pclog("Opening MIDI port %s\n", portname);
+
+	if (snd_rawmidi_open(NULL, &midiout, portname, SND_RAWMIDI_SYNC) < 0)
+	{
+		pclog("Failed to open MIDI\n");
+		return;
+	}
+}
+
+void midi_close()
+{
+	if (midiout != NULL)
+	{
+		snd_rawmidi_close(midiout);
+		midiout = NULL;
+	}
+}
+
+static int midi_pos, midi_len;
+static uint8_t midi_command[4];
+static int midi_lengths[8] = {3, 3, 3, 3, 2, 2, 3, 1};
+static int midi_insysex;
+static uint8_t midi_sysex_data[1024+2];
+
+void midi_write(uint8_t val)
+{
+	//pclog("Write MIDI %02x\n", val);
+
+        if ((val & 0x80) && !(val == 0xf7 && midi_insysex))
+        {
+                midi_pos = 0;
+                midi_len = midi_lengths[(val >> 4) & 7];
+                midi_command[0] = midi_command[1] = midi_command[2] = midi_command[3] = 0;
+                if (val == 0xf0)
+                        midi_insysex = 1;
+        }
+
+        if (midi_insysex)
+        {
+                midi_sysex_data[midi_pos++] = val;
+                
+                if (val == 0xf7 || midi_pos >= 1024+2)
+		{
+/*			pclog("MIDI send sysex %i: ", midi_pos);
+			for (int i = 0; i < midi_pos; i++)
+				pclog("%02x ", midi_sysex_data[i]);
+			pclog("\n");*/
+			snd_rawmidi_write(midiout, midi_sysex_data, midi_pos);
+//			pclog("Sent sysex\n");
+			midi_insysex = 0;
+		}
+                return;
+        }
+                        
+        if (midi_len)
+        {                
+                midi_command[midi_pos] = val;
+                
+                midi_pos++;
+                
+                if (midi_pos == midi_len)
+		{
+//			pclog("MIDI send %i: %02x %02x %02x %02x\n", midi_len, midi_command[0], midi_command[1], midi_command[2], midi_command[3]);
+                        snd_rawmidi_write(midiout, midi_command, midi_len);
+		}
+        }
+}
+
+int midi_get_num_devs()
+{
+	if (!midi_queried)
+		midi_query();
+
+	return midi_device_count;
+}
+
+void midi_get_dev_name(int num, char *s)
+{
+	strcpy(s, midi_devices[num].name);
+}