ALSA: firewire-tascam: add support for incoming MIDI messages by asynchronous transaction

TASCAM FireWire series use asynchronous transaction to transfer MIDI
messages. The transaction is sent to a registered address.

This commit supports the incoming MIDI messages. The messages in the
transaction include some quirks:
 * Two quadlets are used for one MIDI message and one timestamp.
 * Usually, the first byte of the first quadlet includes MIDI port and MSB
   4 bit of MIDI status. For system exclusive message, the first byte
   includes MIDI port and 0x04, or 0x07 in the end of the message.
 * The rest of the first quadlet includes MIDI bytes up to 3.
 * Several set of MIDI messages and timestamp can be transferred in one
   block transaction, up to 8 sets.

I note that TASCAM FireWire series ignores ID bytes of system exclusive
message. When receiving system exclusive messages with ID bytes on physical
MIDI bus, the series transfers the messages without ID bytes on IEEE 1394
bus, and vice versa.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 18 insertions, 0 deletions

diff --git a/sound/firewire/tascam/tascam.h b/sound/firewire/tascam/tascam.h
index 75a3b9a81fea..b0e602bb5c8f 100644
--- a/sound/firewire/tascam/tascam.h
+++ b/sound/firewire/tascam/tascam.h
@@ -25,6 +25,7 @@
 #include <sound/pcm_params.h>
 #include <sound/firewire.h>
 #include <sound/hwdep.h>
+#include <sound/rawmidi.h>
 
 #include "../lib.h"
 #include "../amdtp-stream.h"
@@ -41,6 +42,9 @@ struct snd_tscm_spec {
 	bool is_controller;
 };
 
+#define TSCM_MIDI_IN_PORT_MAX	4
+#define TSCM_MIDI_OUT_PORT_MAX	4
+
 struct snd_tscm {
 	struct snd_card *card;
 	struct fw_unit *unit;
@@ -59,6 +63,10 @@ struct snd_tscm {
 	int dev_lock_count;
 	bool dev_lock_changed;
 	wait_queue_head_t hwdep_wait;
+
+	/* For MIDI message incoming transactions. */
+	struct fw_address_handler async_handler;
+	struct snd_rawmidi_substream *tx_midi_substreams[TSCM_MIDI_IN_PORT_MAX];
 };
 
 #define TSCM_ADDR_BASE			0xffff00000000ull
@@ -81,6 +89,12 @@ struct snd_tscm {
 #define TSCM_OFFSET_CLOCK_STATUS	0x0228
 #define TSCM_OFFSET_SET_OPTION		0x022c
 
+#define TSCM_OFFSET_MIDI_TX_ON		0x0300
+#define TSCM_OFFSET_MIDI_TX_ADDR_HI	0x0304
+#define TSCM_OFFSET_MIDI_TX_ADDR_LO	0x0308
+
+#define TSCM_OFFSET_MIDI_RX_QUAD	0x4000
+
 enum snd_tscm_clock {
 	SND_TSCM_CLOCK_INTERNAL = 0,
 	SND_TSCM_CLOCK_WORD	= 1,
@@ -108,6 +122,10 @@ void snd_tscm_stream_lock_changed(struct snd_tscm *tscm);
 int snd_tscm_stream_lock_try(struct snd_tscm *tscm);
 void snd_tscm_stream_lock_release(struct snd_tscm *tscm);
 
+int snd_tscm_transaction_register(struct snd_tscm *tscm);
+int snd_tscm_transaction_reregister(struct snd_tscm *tscm);
+void snd_tscm_transaction_unregister(struct snd_tscm *tscm);
+
 void snd_tscm_proc_init(struct snd_tscm *tscm);
 
 int snd_tscm_create_pcm_devices(struct snd_tscm *tscm);