cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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bebob_yamaha_terratec.c (2224B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * bebob_yamaha.c - a part of driver for BeBoB based devices
      4 *
      5 * Copyright (c) 2013-2014 Takashi Sakamoto
      6 */
      7
      8#include "./bebob.h"
      9
     10/*
     11 * NOTE:
     12 * Yamaha GO44 is not designed to be used as stand-alone mixer. So any streams
     13 * must be accompanied. If changing the state, a LED on the device starts to
     14 * blink and its sync status is false. In this state, the device sounds nothing
     15 * even if streaming. To start streaming at the current sampling rate is only
     16 * way to recover this state. GO46 is better for stand-alone mixer.
     17 *
     18 * Both of them have a capability to change its sampling rate up to 192.0kHz.
     19 * At 192.0kHz, the device reports 4 PCM-in, 1 MIDI-in, 6 PCM-out, 1 MIDI-out.
     20 * But Yamaha's driver reduce 2 PCM-in, 1 MIDI-in, 2 PCM-out, 1 MIDI-out to use
     21 * 'Extended Stream Format Information Command - Single Request' in 'Additional
     22 * AVC commands' defined by BridgeCo.
     23 * This ALSA driver don't do this because a bit tiresome. Then isochronous
     24 * streaming with many asynchronous transactions brings sounds with noises.
     25 * Unfortunately current 'ffado-mixer' generated many asynchronous transaction
     26 * to observe device's state, mainly check cmp connection and signal format. I
     27 * recommend users to close ffado-mixer at 192.0kHz if mixer is needless.
     28 *
     29 * Terratec PHASE 24 FW and PHASE X24 FW are internally the same as
     30 * Yamaha GO 44 and GO 46. Yamaha and Terratec had cooperated for these models.
     31 */
     32
     33static const enum snd_bebob_clock_type clk_src_types[] = {
     34	SND_BEBOB_CLOCK_TYPE_INTERNAL,
     35	SND_BEBOB_CLOCK_TYPE_EXTERNAL,	/* S/PDIF */
     36};
     37static int
     38clk_src_get(struct snd_bebob *bebob, unsigned int *id)
     39{
     40	int err;
     41
     42	err = avc_audio_get_selector(bebob->unit, 0, 4, id);
     43	if (err < 0)
     44		return err;
     45
     46	if (*id >= ARRAY_SIZE(clk_src_types))
     47		return -EIO;
     48
     49	return 0;
     50}
     51static const struct snd_bebob_clock_spec clock_spec = {
     52	.num	= ARRAY_SIZE(clk_src_types),
     53	.types	= clk_src_types,
     54	.get	= &clk_src_get,
     55};
     56static const struct snd_bebob_rate_spec rate_spec = {
     57	.get	= &snd_bebob_stream_get_rate,
     58	.set	= &snd_bebob_stream_set_rate,
     59};
     60const struct snd_bebob_spec yamaha_terratec_spec = {
     61	.clock	= &clock_spec,
     62	.rate	= &rate_spec,
     63	.meter	= NULL
     64};