sound/usb/line6/midi.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Line 6 Linux USB driver
  *
  * Copyright (C) 2004-2010 Markus Grabner (line6@grabner-graz.at)
  */

 #include <linux/slab.h>
 #include <linux/usb.h>
 #include <linux/export.h>
 #include <sound/core.h>
 #include <sound/rawmidi.h>

 #include "driver.h"
 #include "midi.h"

 #define line6_rawmidi_substream_midi(substream) \
 	((struct snd_line6_midi *)((substream)->rmidi->private_data))

 static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
 			   int length);

 /*
 	Pass data received via USB to MIDI.
 */
 void line6_midi_receive(struct usb_line6 *line6, unsigned char *data,
 			int length)
 {
 	if (line6->line6midi->substream_receive)
 		snd_rawmidi_receive(line6->line6midi->substream_receive,
 				    data, length);
 }

 /*
 	Read data from MIDI buffer and transmit them via USB.
 */
 static void line6_midi_transmit(struct snd_rawmidi_substream *substream)
 {
 	struct usb_line6 *line6 =
 	    line6_rawmidi_substream_midi(substream)->line6;
 	struct snd_line6_midi *line6midi = line6->line6midi;
 	struct midi_buffer *mb = &line6midi->midibuf_out;
 	unsigned char chunk[LINE6_FALLBACK_MAXPACKETSIZE];
 	int req, done;

 	for (;;) {
 		req = min3(line6_midibuf_bytes_free(mb), line6->max_packet_size,
 			   LINE6_FALLBACK_MAXPACKETSIZE);
 		done = snd_rawmidi_transmit_peek(substream, chunk, req);

 		if (done == 0)
 			break;

 		line6_midibuf_write(mb, chunk, done);
 		snd_rawmidi_transmit_ack(substream, done);
 	}

 	for (;;) {
 		done = line6_midibuf_read(mb, chunk,
 					  LINE6_FALLBACK_MAXPACKETSIZE,
 					  LINE6_MIDIBUF_READ_TX);

 		if (done == 0)
 			break;

 		send_midi_async(line6, chunk, done);
 	}
 }

 /*
 	Notification of completion of MIDI transmission.
 */
 static void midi_sent(struct urb *urb)
 {
 	unsigned long flags;
 	int status;
 	int num;
 	struct usb_line6 *line6 = (struct usb_line6 *)urb->context;

 	status = urb->status;
 	kfree(urb->transfer_buffer);
 	usb_free_urb(urb);

 	if (status == -ESHUTDOWN)
 		return;

 	spin_lock_irqsave(&line6->line6midi->lock, flags);
 	num = --line6->line6midi->num_active_send_urbs;

 	if (num == 0) {
 		line6_midi_transmit(line6->line6midi->substream_transmit);
 		num = line6->line6midi->num_active_send_urbs;
 	}

 	if (num == 0)
 		wake_up(&line6->line6midi->send_wait);

 	spin_unlock_irqrestore(&line6->line6midi->lock, flags);
 }

 /*
 	Send an asynchronous MIDI message.
 	Assumes that line6->line6midi->lock is held
 	(i.e., this function is serialized).
 */
 static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
 			   int length)
 {
 	struct urb *urb;
 	int retval;
 	unsigned char *transfer_buffer;

 	urb = usb_alloc_urb(0, GFP_ATOMIC);

 	if (urb == NULL)
 		return -ENOMEM;

 	transfer_buffer = kmemdup(data, length, GFP_ATOMIC);

 	if (transfer_buffer == NULL) {
 		usb_free_urb(urb);
 		return -ENOMEM;
 	}

 	usb_fill_int_urb(urb, line6->usbdev,
 			 usb_sndintpipe(line6->usbdev,
 					 line6->properties->ep_ctrl_w),
 			 transfer_buffer, length, midi_sent, line6,
 			 line6->interval);
 	urb->actual_length = 0;
 	retval = usb_urb_ep_type_check(urb);
 	if (retval < 0)
 		goto error;

 	retval = usb_submit_urb(urb, GFP_ATOMIC);
 	if (retval < 0)
 		goto error;

 	++line6->line6midi->num_active_send_urbs;
 	return 0;

  error:
 	dev_err(line6->ifcdev, "usb_submit_urb failed\n");
 	usb_free_urb(urb);
 	return retval;
 }

 static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
 {
 	return 0;
 }

 static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
 {
 	return 0;
 }

 static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream,
 				      int up)
 {
 	unsigned long flags;
 	struct usb_line6 *line6 =
 	    line6_rawmidi_substream_midi(substream)->line6;

 	line6->line6midi->substream_transmit = substream;
 	spin_lock_irqsave(&line6->line6midi->lock, flags);

 	if (line6->line6midi->num_active_send_urbs == 0)
 		line6_midi_transmit(substream);

 	spin_unlock_irqrestore(&line6->line6midi->lock, flags);
 }

 static void line6_midi_output_drain(struct snd_rawmidi_substream *substream)
 {
 	struct usb_line6 *line6 =
 	    line6_rawmidi_substream_midi(substream)->line6;
 	struct snd_line6_midi *midi = line6->line6midi;

 	wait_event_interruptible(midi->send_wait,
 				 midi->num_active_send_urbs == 0);
 }

 static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
 {
 	return 0;
 }

 static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
 {
 	return 0;
 }

 static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream,
 				     int up)
 {
 	struct usb_line6 *line6 =
 	    line6_rawmidi_substream_midi(substream)->line6;

 	if (up)
 		line6->line6midi->substream_receive = substream;
 	else
 		line6->line6midi->substream_receive = NULL;
 }

 static const struct snd_rawmidi_ops line6_midi_output_ops = {
 	.open = line6_midi_output_open,
 	.close = line6_midi_output_close,
 	.trigger = line6_midi_output_trigger,
 	.drain = line6_midi_output_drain,
 };

 static const struct snd_rawmidi_ops line6_midi_input_ops = {
 	.open = line6_midi_input_open,
 	.close = line6_midi_input_close,
 	.trigger = line6_midi_input_trigger,
 };

 /* Create a MIDI device */
 static int snd_line6_new_midi(struct usb_line6 *line6,
 			      struct snd_rawmidi **rmidi_ret)
 {
 	struct snd_rawmidi *rmidi;
 	int err;

 	err = snd_rawmidi_new(line6->card, "Line 6 MIDI", 0, 1, 1, rmidi_ret);
 	if (err < 0)
 		return err;

 	rmidi = *rmidi_ret;
 	strcpy(rmidi->id, line6->properties->id);
 	strcpy(rmidi->name, line6->properties->name);

 	rmidi->info_flags =
 	    SNDRV_RAWMIDI_INFO_OUTPUT |
 	    SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;

 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 			    &line6_midi_output_ops);
 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 			    &line6_midi_input_ops);
 	return 0;
 }

 /* MIDI device destructor */
 static void snd_line6_midi_free(struct snd_rawmidi *rmidi)
 {
 	struct snd_line6_midi *line6midi = rmidi->private_data;

 	line6_midibuf_destroy(&line6midi->midibuf_in);
 	line6_midibuf_destroy(&line6midi->midibuf_out);
 	kfree(line6midi);
 }

 /*
 	Initialize the Line 6 MIDI subsystem.
 */
 int line6_init_midi(struct usb_line6 *line6)
 {
 	int err;
 	struct snd_rawmidi *rmidi;
 	struct snd_line6_midi *line6midi;

 	if (!(line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI)) {
 		/* skip MIDI initialization and report success */
 		return 0;
 	}

 	err = snd_line6_new_midi(line6, &rmidi);
 	if (err < 0)
 		return err;

 	line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL);
 	if (!line6midi)
 		return -ENOMEM;

 	rmidi->private_data = line6midi;
 	rmidi->private_free = snd_line6_midi_free;

 	init_waitqueue_head(&line6midi->send_wait);
 	spin_lock_init(&line6midi->lock);
 	line6midi->line6 = line6;

 	err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0);
 	if (err < 0)
 		return err;

 	err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1);
 	if (err < 0)
 		return err;

 	line6->line6midi = line6midi;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(line6_init_midi);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Line 6 Linux USB driver
	*
	* Copyright (C) 2004-2010 Markus Grabner (line6@grabner-graz.at)
	*/

	#include <linux/slab.h>
	#include <linux/usb.h>
	#include <linux/export.h>
	#include <sound/core.h>
	#include <sound/rawmidi.h>

	#include "driver.h"
	#include "midi.h"

	#define line6_rawmidi_substream_midi(substream) \
	((struct snd_line6_midi *)((substream)->rmidi->private_data))

	static int send_midi_async(struct usb_line6 line6, unsigned char data,
	int length);

	/*
	Pass data received via USB to MIDI.
	*/
	void line6_midi_receive(struct usb_line6 line6, unsigned char data,
	int length)
	{
	if (line6->line6midi->substream_receive)
	snd_rawmidi_receive(line6->line6midi->substream_receive,
	data, length);
	}

	/*
	Read data from MIDI buffer and transmit them via USB.
	*/
	static void line6_midi_transmit(struct snd_rawmidi_substream *substream)
	{
	struct usb_line6 *line6 =
	line6_rawmidi_substream_midi(substream)->line6;
	struct snd_line6_midi *line6midi = line6->line6midi;
	struct midi_buffer *mb = &line6midi->midibuf_out;
	unsigned char chunk[LINE6_FALLBACK_MAXPACKETSIZE];
	int req, done;

	for (;;) {
	req = min3(line6_midibuf_bytes_free(mb), line6->max_packet_size,
	LINE6_FALLBACK_MAXPACKETSIZE);
	done = snd_rawmidi_transmit_peek(substream, chunk, req);

	if (done == 0)
	break;

	line6_midibuf_write(mb, chunk, done);
	snd_rawmidi_transmit_ack(substream, done);
	}

	for (;;) {
	done = line6_midibuf_read(mb, chunk,
	LINE6_FALLBACK_MAXPACKETSIZE,
	LINE6_MIDIBUF_READ_TX);

	if (done == 0)
	break;

	send_midi_async(line6, chunk, done);
	}
	}

	/*
	Notification of completion of MIDI transmission.
	*/
	static void midi_sent(struct urb *urb)
	{
	unsigned long flags;
	int status;
	int num;
	struct usb_line6 line6 = (struct usb_line6 )urb->context;

	status = urb->status;
	kfree(urb->transfer_buffer);
	usb_free_urb(urb);

	if (status == -ESHUTDOWN)
	return;

	spin_lock_irqsave(&line6->line6midi->lock, flags);
	num = --line6->line6midi->num_active_send_urbs;

	if (num == 0) {
	line6_midi_transmit(line6->line6midi->substream_transmit);
	num = line6->line6midi->num_active_send_urbs;
	}

	if (num == 0)
	wake_up(&line6->line6midi->send_wait);

	spin_unlock_irqrestore(&line6->line6midi->lock, flags);
	}

	/*
	Send an asynchronous MIDI message.
	Assumes that line6->line6midi->lock is held
	(i.e., this function is serialized).
	*/
	static int send_midi_async(struct usb_line6 line6, unsigned char data,
	int length)
	{
	struct urb *urb;
	int retval;
	unsigned char *transfer_buffer;

	urb = usb_alloc_urb(0, GFP_ATOMIC);

	if (urb == NULL)
	return -ENOMEM;

	transfer_buffer = kmemdup(data, length, GFP_ATOMIC);

	if (transfer_buffer == NULL) {
	usb_free_urb(urb);
	return -ENOMEM;
	}

	usb_fill_int_urb(urb, line6->usbdev,
	usb_sndintpipe(line6->usbdev,
	line6->properties->ep_ctrl_w),
	transfer_buffer, length, midi_sent, line6,
	line6->interval);
	urb->actual_length = 0;
	retval = usb_urb_ep_type_check(urb);
	if (retval < 0)
	goto error;

	retval = usb_submit_urb(urb, GFP_ATOMIC);
	if (retval < 0)
	goto error;

	++line6->line6midi->num_active_send_urbs;
	return 0;

	error:
	dev_err(line6->ifcdev, "usb_submit_urb failed\n");
	usb_free_urb(urb);
	return retval;
	}

	static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
	{
	return 0;
	}

	static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
	{
	return 0;
	}

	static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream,
	int up)
	{
	unsigned long flags;
	struct usb_line6 *line6 =
	line6_rawmidi_substream_midi(substream)->line6;

	line6->line6midi->substream_transmit = substream;
	spin_lock_irqsave(&line6->line6midi->lock, flags);

	if (line6->line6midi->num_active_send_urbs == 0)
	line6_midi_transmit(substream);

	spin_unlock_irqrestore(&line6->line6midi->lock, flags);
	}

	static void line6_midi_output_drain(struct snd_rawmidi_substream *substream)
	{
	struct usb_line6 *line6 =
	line6_rawmidi_substream_midi(substream)->line6;
	struct snd_line6_midi *midi = line6->line6midi;

	wait_event_interruptible(midi->send_wait,
	midi->num_active_send_urbs == 0);
	}

	static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
	{
	return 0;
	}

	static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
	{
	return 0;
	}

	static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream,
	int up)
	{
	struct usb_line6 *line6 =
	line6_rawmidi_substream_midi(substream)->line6;

	if (up)
	line6->line6midi->substream_receive = substream;
	else
	line6->line6midi->substream_receive = NULL;
	}

	static const struct snd_rawmidi_ops line6_midi_output_ops = {
	.open = line6_midi_output_open,
	.close = line6_midi_output_close,
	.trigger = line6_midi_output_trigger,
	.drain = line6_midi_output_drain,
	};

	static const struct snd_rawmidi_ops line6_midi_input_ops = {
	.open = line6_midi_input_open,
	.close = line6_midi_input_close,
	.trigger = line6_midi_input_trigger,
	};

	/* Create a MIDI device */
	static int snd_line6_new_midi(struct usb_line6 *line6,
	struct snd_rawmidi **rmidi_ret)
	{
	struct snd_rawmidi *rmidi;
	int err;

	err = snd_rawmidi_new(line6->card, "Line 6 MIDI", 0, 1, 1, rmidi_ret);
	if (err < 0)
	return err;

	rmidi = *rmidi_ret;
	strcpy(rmidi->id, line6->properties->id);
	strcpy(rmidi->name, line6->properties->name);

	rmidi->info_flags =
	SNDRV_RAWMIDI_INFO_OUTPUT \|
	SNDRV_RAWMIDI_INFO_INPUT \| SNDRV_RAWMIDI_INFO_DUPLEX;

	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
	&line6_midi_output_ops);
	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
	&line6_midi_input_ops);
	return 0;
	}

	/* MIDI device destructor */
	static void snd_line6_midi_free(struct snd_rawmidi *rmidi)
	{
	struct snd_line6_midi *line6midi = rmidi->private_data;

	line6_midibuf_destroy(&line6midi->midibuf_in);
	line6_midibuf_destroy(&line6midi->midibuf_out);
	kfree(line6midi);
	}

	/*
	Initialize the Line 6 MIDI subsystem.
	*/
	int line6_init_midi(struct usb_line6 *line6)
	{
	int err;
	struct snd_rawmidi *rmidi;
	struct snd_line6_midi *line6midi;

	if (!(line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI)) {
	/* skip MIDI initialization and report success */
	return 0;
	}

	err = snd_line6_new_midi(line6, &rmidi);
	if (err < 0)
	return err;

	line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL);
	if (!line6midi)
	return -ENOMEM;

	rmidi->private_data = line6midi;
	rmidi->private_free = snd_line6_midi_free;

	init_waitqueue_head(&line6midi->send_wait);
	spin_lock_init(&line6midi->lock);
	line6midi->line6 = line6;

	err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0);
	if (err < 0)
	return err;

	err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1);
	if (err < 0)
	return err;

	line6->line6midi = line6midi;
	return 0;
	}
	EXPORT_SYMBOL_GPL(line6_init_midi);