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Diffstat (limited to 'sound/firewire/bebob/bebob_yamaha.c')
-rw-r--r--sound/firewire/bebob/bebob_yamaha.c50
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diff --git a/sound/firewire/bebob/bebob_yamaha.c b/sound/firewire/bebob/bebob_yamaha.c
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+/*
+ * bebob_yamaha.c - a part of driver for BeBoB based devices
+ *
+ * Copyright (c) 2013-2014 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#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 revocer 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
+ * reccomend users to close ffado-mixer at 192.0kHz if mixer is needless.
+ */
+
+static const char *const clk_src_labels[] = {SND_BEBOB_CLOCK_INTERNAL, "SPDIF"};
+static int
+clk_src_get(struct snd_bebob *bebob, unsigned int *id)
+{
+ return avc_audio_get_selector(bebob->unit, 0, 4, id);
+}
+static struct snd_bebob_clock_spec clock_spec = {
+ .num = ARRAY_SIZE(clk_src_labels),
+ .labels = clk_src_labels,
+ .get = &clk_src_get,
+};
+static struct snd_bebob_rate_spec rate_spec = {
+ .get = &snd_bebob_stream_get_rate,
+ .set = &snd_bebob_stream_set_rate,
+};
+struct snd_bebob_spec yamaha_go_spec = {
+ .clock = &clock_spec,
+ .rate = &rate_spec,
+ .meter = NULL
+};