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 enum snd_bebob_clock_type clk_src_types[] = { 32 SND_BEBOB_CLOCK_TYPE_INTERNAL, 33 SND_BEBOB_CLOCK_TYPE_EXTERNAL, /* S/PDIF */ 34}; 35static int 36clk_src_get(struct snd_bebob *bebob, unsigned int *id) 37{ 38 int err; 39 40 err = avc_audio_get_selector(bebob->unit, 0, 4, id); 41 if (err < 0) 42 return err; 43 44 if (*id >= ARRAY_SIZE(clk_src_types)) 45 return -EIO; 46 47 return 0; 48} 49static const struct snd_bebob_clock_spec clock_spec = { 50 .num = ARRAY_SIZE(clk_src_types), 51 .types = clk_src_types, 52 .get = &clk_src_get, 53}; 54static const struct snd_bebob_rate_spec rate_spec = { 55 .get = &snd_bebob_stream_get_rate, 56 .set = &snd_bebob_stream_set_rate, 57}; 58const struct snd_bebob_spec yamaha_go_spec = { 59 .clock = &clock_spec, 60 .rate = &rate_spec, 61 .meter = NULL 62}; 63