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 recover 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  * recommend users to close ffado-mixer at 192.0kHz if mixer is needless.
29  *
30  * Terratec PHASE 24 FW and PHASE X24 FW are internally the same as
31  * Yamaha GO 44 and GO 46. Yamaha and Terratec had cooperated for these models.
32  */
33 
34 static const enum snd_bebob_clock_type clk_src_types[] = {
35 	SND_BEBOB_CLOCK_TYPE_INTERNAL,
36 	SND_BEBOB_CLOCK_TYPE_EXTERNAL,	/* S/PDIF */
37 };
38 static int
39 clk_src_get(struct snd_bebob *bebob, unsigned int *id)
40 {
41 	int err;
42 
43 	err = avc_audio_get_selector(bebob->unit, 0, 4, id);
44 	if (err < 0)
45 		return err;
46 
47 	if (*id >= ARRAY_SIZE(clk_src_types))
48 		return -EIO;
49 
50 	return 0;
51 }
52 static const struct snd_bebob_clock_spec clock_spec = {
53 	.num	= ARRAY_SIZE(clk_src_types),
54 	.types	= clk_src_types,
55 	.get	= &clk_src_get,
56 };
57 static const struct snd_bebob_rate_spec rate_spec = {
58 	.get	= &snd_bebob_stream_get_rate,
59 	.set	= &snd_bebob_stream_set_rate,
60 };
61 const struct snd_bebob_spec yamaha_terratec_spec = {
62 	.clock	= &clock_spec,
63 	.rate	= &rate_spec,
64 	.meter	= NULL
65 };
66