sound/firewire/fireface/ff-midi.c

Source file repositories/reference/linux-study-clean/sound/firewire/fireface/ff-midi.c

File Facts

System
Linux kernel
Corpus path
sound/firewire/fireface/ff-midi.c
Extension
.c
Size
3184 bytes
Lines
123
Domain
Driver Families
Bucket
sound/firewire
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * ff-midi.c - a part of driver for RME Fireface series
 *
 * Copyright (c) 2015-2017 Takashi Sakamoto
 */

#include "ff.h"

static int midi_capture_open(struct snd_rawmidi_substream *substream)
{
	/* Do nothing. */
	return 0;
}

static int midi_playback_open(struct snd_rawmidi_substream *substream)
{
	struct snd_ff *ff = substream->rmidi->private_data;

	/* Initialize internal status. */
	ff->on_sysex[substream->number] = 0;
	ff->rx_midi_error[substream->number] = false;

	WRITE_ONCE(ff->rx_midi_substreams[substream->number], substream);

	return 0;
}

static int midi_capture_close(struct snd_rawmidi_substream *substream)
{
	/* Do nothing. */
	return 0;
}

static int midi_playback_close(struct snd_rawmidi_substream *substream)
{
	struct snd_ff *ff = substream->rmidi->private_data;

	cancel_work_sync(&ff->rx_midi_work[substream->number]);
	WRITE_ONCE(ff->rx_midi_substreams[substream->number], NULL);

	return 0;
}

static void midi_capture_trigger(struct snd_rawmidi_substream *substream,
				 int up)
{
	struct snd_ff *ff = substream->rmidi->private_data;

	guard(spinlock_irqsave)(&ff->lock);

	if (up)
		WRITE_ONCE(ff->tx_midi_substreams[substream->number],
			   substream);
	else
		WRITE_ONCE(ff->tx_midi_substreams[substream->number], NULL);
}

static void midi_playback_trigger(struct snd_rawmidi_substream *substream,
				  int up)
{
	struct snd_ff *ff = substream->rmidi->private_data;

	guard(spinlock_irqsave)(&ff->lock);

	if (up || !ff->rx_midi_error[substream->number])
		schedule_work(&ff->rx_midi_work[substream->number]);
}

static void set_midi_substream_names(struct snd_rawmidi_str *stream,
				     const char *const name)
{
	struct snd_rawmidi_substream *substream;

	list_for_each_entry(substream, &stream->substreams, list) {
		scnprintf(substream->name, sizeof(substream->name),
			  "%s MIDI %d", name, substream->number + 1);
	}
}

int snd_ff_create_midi_devices(struct snd_ff *ff)
{
	static const struct snd_rawmidi_ops midi_capture_ops = {
		.open		= midi_capture_open,
		.close		= midi_capture_close,
		.trigger	= midi_capture_trigger,
	};
	static const struct snd_rawmidi_ops midi_playback_ops = {
		.open		= midi_playback_open,
		.close		= midi_playback_close,

Annotation

Implementation Notes