1/*
2 * bebob_yamaha.c - a part of driver for BeBoB based devices
3 *
4 * Copyright (c) 2013-2014 Takashi Sakamoto
5 *
6 * Licensed under the terms of the GNU General Public License, version 2.
7 */
8
9#include "./bebob.h"
10
11/*
12 * NOTE:
13 * Yamaha GO44 is not designed to be used as stand-alone mixer. So any streams
14 * must be accompanied. If changing the state, a LED on the device starts to
15 * blink and its sync status is false. In this state, the device sounds nothing
16 * even if streaming. To start streaming at the current sampling rate is only
17 * way to revocer this state. GO46 is better for stand-alone mixer.
18 *
19 * Both of them have a capability to change its sampling rate up to 192.0kHz.
20 * At 192.0kHz, the device reports 4 PCM-in, 1 MIDI-in, 6 PCM-out, 1 MIDI-out.
21 * But Yamaha's driver reduce 2 PCM-in, 1 MIDI-in, 2 PCM-out, 1 MIDI-out to use
22 * 'Extended Stream Format Information Command - Single Request' in 'Additional
23 * AVC commands' defined by BridgeCo.
24 * This ALSA driver don't do this because a bit tiresome. Then isochronous
25 * streaming with many asynchronous transactions brings sounds with noises.
26 * Unfortunately current 'ffado-mixer' generated many asynchronous transaction
27 * to observe device's state, mainly check cmp connection and signal format. I
28 * reccomend users to close ffado-mixer at 192.0kHz if mixer is needless.
29 */
30
31static const char *const clk_src_labels[] = {SND_BEBOB_CLOCK_INTERNAL, "SPDIF"};
32static int
33clk_src_get(struct snd_bebob *bebob, unsigned int *id)
34{
35	return avc_audio_get_selector(bebob->unit, 0, 4, id);
36}
37static struct snd_bebob_clock_spec clock_spec = {
38	.num	= ARRAY_SIZE(clk_src_labels),
39	.labels	= clk_src_labels,
40	.get	= &clk_src_get,
41};
42static struct snd_bebob_rate_spec rate_spec = {
43	.get	= &snd_bebob_stream_get_rate,
44	.set	= &snd_bebob_stream_set_rate,
45};
46struct snd_bebob_spec yamaha_go_spec = {
47	.clock	= &clock_spec,
48	.rate	= &rate_spec,
49	.meter	= NULL
50};
51