linux/sound/usb/line6/midi.c

298 lines
6.9 KiB
C

/*
* Line 6 Linux USB driver
*
* Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2.
*
*/
#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 = min(line6_midibuf_bytes_free(mb), line6->max_packet_size);
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);
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_sndbulkpipe(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);