linux/sound/firewire/bebob/bebob_yamaha_terratec.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * bebob_yamaha.c - a part of driver for BeBoB based devices
 *
 * Copyright (c) 2013-2014 Takashi Sakamoto
 */

#include "./bebob.h"

/*
 * NOTE:
 * Yamaha GO44 is not designed to be used as stand-alone mixer. So any streams
 * must be accompanied. If changing the state, a LED on the device starts to
 * blink and its sync status is false. In this state, the device sounds nothing
 * even if streaming. To start streaming at the current sampling rate is only
 * way to recover this state. GO46 is better for stand-alone mixer.
 *
 * Both of them have a capability to change its sampling rate up to 192.0kHz.
 * At 192.0kHz, the device reports 4 PCM-in, 1 MIDI-in, 6 PCM-out, 1 MIDI-out.
 * But Yamaha's driver reduce 2 PCM-in, 1 MIDI-in, 2 PCM-out, 1 MIDI-out to use
 * 'Extended Stream Format Information Command - Single Request' in 'Additional
 * AVC commands' defined by BridgeCo.
 * This ALSA driver don't do this because a bit tiresome. Then isochronous
 * streaming with many asynchronous transactions brings sounds with noises.
 * Unfortunately current 'ffado-mixer' generated many asynchronous transaction
 * to observe device's state, mainly check cmp connection and signal format. I
 * recommend users to close ffado-mixer at 192.0kHz if mixer is needless.
 *
 * Terratec PHASE 24 FW and PHASE X24 FW are internally the same as
 * Yamaha GO 44 and GO 46. Yamaha and Terratec had cooperated for these models.
 */

static const enum snd_bebob_clock_type clk_src_types[] =;
static int
clk_src_get(struct snd_bebob *bebob, unsigned int *id)
{}
static const struct snd_bebob_clock_spec clock_spec =;
static const struct snd_bebob_rate_spec rate_spec =;
const struct snd_bebob_spec yamaha_terratec_spec =;