LXR linux/sound/firewire/bebob/bebob_yamaha

   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};
  65