linux/drivers/staging/line6/midi.c
<<
>>
Prefs
   1/*
   2 * Line6 Linux USB driver - 0.9.1beta
   3 *
   4 * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
   5 *
   6 *      This program is free software; you can redistribute it and/or
   7 *      modify it under the terms of the GNU General Public License as
   8 *      published by the Free Software Foundation, version 2.
   9 *
  10 */
  11
  12#include <linux/slab.h>
  13#include <linux/usb.h>
  14#include <sound/core.h>
  15#include <sound/rawmidi.h>
  16
  17#include "audio.h"
  18#include "driver.h"
  19#include "midi.h"
  20#include "pod.h"
  21#include "usbdefs.h"
  22
  23#define line6_rawmidi_substream_midi(substream) \
  24        ((struct snd_line6_midi *)((substream)->rmidi->private_data))
  25
  26static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
  27                           int length);
  28
  29/*
  30        Pass data received via USB to MIDI.
  31*/
  32void line6_midi_receive(struct usb_line6 *line6, unsigned char *data,
  33                        int length)
  34{
  35        if (line6->line6midi->substream_receive)
  36                snd_rawmidi_receive(line6->line6midi->substream_receive,
  37                                    data, length);
  38}
  39
  40/*
  41        Read data from MIDI buffer and transmit them via USB.
  42*/
  43static void line6_midi_transmit(struct snd_rawmidi_substream *substream)
  44{
  45        struct usb_line6 *line6 =
  46            line6_rawmidi_substream_midi(substream)->line6;
  47        struct snd_line6_midi *line6midi = line6->line6midi;
  48        struct midi_buffer *mb = &line6midi->midibuf_out;
  49        unsigned long flags;
  50        unsigned char chunk[LINE6_FALLBACK_MAXPACKETSIZE];
  51        int req, done;
  52
  53        spin_lock_irqsave(&line6->line6midi->midi_transmit_lock, flags);
  54
  55        for (;;) {
  56                req = min(line6_midibuf_bytes_free(mb), line6->max_packet_size);
  57                done = snd_rawmidi_transmit_peek(substream, chunk, req);
  58
  59                if (done == 0)
  60                        break;
  61
  62                line6_midibuf_write(mb, chunk, done);
  63                snd_rawmidi_transmit_ack(substream, done);
  64        }
  65
  66        for (;;) {
  67                done = line6_midibuf_read(mb, chunk,
  68                                          LINE6_FALLBACK_MAXPACKETSIZE);
  69
  70                if (done == 0)
  71                        break;
  72
  73                send_midi_async(line6, chunk, done);
  74        }
  75
  76        spin_unlock_irqrestore(&line6->line6midi->midi_transmit_lock, flags);
  77}
  78
  79/*
  80        Notification of completion of MIDI transmission.
  81*/
  82static void midi_sent(struct urb *urb)
  83{
  84        unsigned long flags;
  85        int status;
  86        int num;
  87        struct usb_line6 *line6 = (struct usb_line6 *)urb->context;
  88
  89        status = urb->status;
  90        kfree(urb->transfer_buffer);
  91        usb_free_urb(urb);
  92
  93        if (status == -ESHUTDOWN)
  94                return;
  95
  96        spin_lock_irqsave(&line6->line6midi->send_urb_lock, flags);
  97        num = --line6->line6midi->num_active_send_urbs;
  98
  99        if (num == 0) {
 100                line6_midi_transmit(line6->line6midi->substream_transmit);
 101                num = line6->line6midi->num_active_send_urbs;
 102        }
 103
 104        if (num == 0)
 105                wake_up(&line6->line6midi->send_wait);
 106
 107        spin_unlock_irqrestore(&line6->line6midi->send_urb_lock, flags);
 108}
 109
 110/*
 111        Send an asynchronous MIDI message.
 112        Assumes that line6->line6midi->send_urb_lock is held
 113        (i.e., this function is serialized).
 114*/
 115static int send_midi_async(struct usb_line6 *line6, unsigned char *data,
 116                           int length)
 117{
 118        struct urb *urb;
 119        int retval;
 120        unsigned char *transfer_buffer;
 121
 122        urb = usb_alloc_urb(0, GFP_ATOMIC);
 123
 124        if (urb == NULL) {
 125                dev_err(line6->ifcdev, "Out of memory\n");
 126                return -ENOMEM;
 127        }
 128
 129        transfer_buffer = kmemdup(data, length, GFP_ATOMIC);
 130
 131        if (transfer_buffer == NULL) {
 132                usb_free_urb(urb);
 133                dev_err(line6->ifcdev, "Out of memory\n");
 134                return -ENOMEM;
 135        }
 136
 137        usb_fill_int_urb(urb, line6->usbdev,
 138                         usb_sndbulkpipe(line6->usbdev,
 139                                         line6->ep_control_write),
 140                         transfer_buffer, length, midi_sent, line6,
 141                         line6->interval);
 142        urb->actual_length = 0;
 143        retval = usb_submit_urb(urb, GFP_ATOMIC);
 144
 145        if (retval < 0) {
 146                dev_err(line6->ifcdev, "usb_submit_urb failed\n");
 147                usb_free_urb(urb);
 148                return retval;
 149        }
 150
 151        ++line6->line6midi->num_active_send_urbs;
 152        return 0;
 153}
 154
 155static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
 156{
 157        return 0;
 158}
 159
 160static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
 161{
 162        return 0;
 163}
 164
 165static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream,
 166                                      int up)
 167{
 168        unsigned long flags;
 169        struct usb_line6 *line6 =
 170            line6_rawmidi_substream_midi(substream)->line6;
 171
 172        line6->line6midi->substream_transmit = substream;
 173        spin_lock_irqsave(&line6->line6midi->send_urb_lock, flags);
 174
 175        if (line6->line6midi->num_active_send_urbs == 0)
 176                line6_midi_transmit(substream);
 177
 178        spin_unlock_irqrestore(&line6->line6midi->send_urb_lock, flags);
 179}
 180
 181static void line6_midi_output_drain(struct snd_rawmidi_substream *substream)
 182{
 183        struct usb_line6 *line6 =
 184            line6_rawmidi_substream_midi(substream)->line6;
 185        struct snd_line6_midi *midi = line6->line6midi;
 186
 187        wait_event_interruptible(midi->send_wait,
 188                                 midi->num_active_send_urbs == 0);
 189}
 190
 191static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
 192{
 193        return 0;
 194}
 195
 196static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
 197{
 198        return 0;
 199}
 200
 201static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream,
 202                                     int up)
 203{
 204        struct usb_line6 *line6 =
 205            line6_rawmidi_substream_midi(substream)->line6;
 206
 207        if (up)
 208                line6->line6midi->substream_receive = substream;
 209        else
 210                line6->line6midi->substream_receive = NULL;
 211}
 212
 213static struct snd_rawmidi_ops line6_midi_output_ops = {
 214        .open = line6_midi_output_open,
 215        .close = line6_midi_output_close,
 216        .trigger = line6_midi_output_trigger,
 217        .drain = line6_midi_output_drain,
 218};
 219
 220static struct snd_rawmidi_ops line6_midi_input_ops = {
 221        .open = line6_midi_input_open,
 222        .close = line6_midi_input_close,
 223        .trigger = line6_midi_input_trigger,
 224};
 225
 226/*
 227        Cleanup the Line6 MIDI device.
 228*/
 229static void line6_cleanup_midi(struct snd_rawmidi *rmidi)
 230{
 231}
 232
 233/* Create a MIDI device */
 234static int snd_line6_new_midi(struct snd_line6_midi *line6midi)
 235{
 236        struct snd_rawmidi *rmidi;
 237        int err;
 238
 239        err = snd_rawmidi_new(line6midi->line6->card, "Line6 MIDI", 0, 1, 1,
 240                              &rmidi);
 241        if (err < 0)
 242                return err;
 243
 244        rmidi->private_data = line6midi;
 245        rmidi->private_free = line6_cleanup_midi;
 246        strcpy(rmidi->id, line6midi->line6->properties->id);
 247        strcpy(rmidi->name, line6midi->line6->properties->name);
 248
 249        rmidi->info_flags =
 250            SNDRV_RAWMIDI_INFO_OUTPUT |
 251            SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX;
 252
 253        snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 254                            &line6_midi_output_ops);
 255        snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 256                            &line6_midi_input_ops);
 257        return 0;
 258}
 259
 260/* MIDI device destructor */
 261static int snd_line6_midi_free(struct snd_device *device)
 262{
 263        struct snd_line6_midi *line6midi = device->device_data;
 264
 265        line6_midibuf_destroy(&line6midi->midibuf_in);
 266        line6_midibuf_destroy(&line6midi->midibuf_out);
 267        return 0;
 268}
 269
 270/*
 271        Initialize the Line6 MIDI subsystem.
 272*/
 273int line6_init_midi(struct usb_line6 *line6)
 274{
 275        static struct snd_device_ops midi_ops = {
 276                .dev_free = snd_line6_midi_free,
 277        };
 278
 279        int err;
 280        struct snd_line6_midi *line6midi;
 281
 282        if (!(line6->properties->capabilities & LINE6_BIT_CONTROL)) {
 283                /* skip MIDI initialization and report success */
 284                return 0;
 285        }
 286
 287        line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL);
 288
 289        if (line6midi == NULL)
 290                return -ENOMEM;
 291
 292        err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0);
 293        if (err < 0) {
 294                kfree(line6midi);
 295                return err;
 296        }
 297
 298        err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1);
 299        if (err < 0) {
 300                kfree(line6midi->midibuf_in.buf);
 301                kfree(line6midi);
 302                return err;
 303        }
 304
 305        line6midi->line6 = line6;
 306        line6->line6midi = line6midi;
 307
 308        err = snd_device_new(line6->card, SNDRV_DEV_RAWMIDI, line6midi,
 309                             &midi_ops);
 310        if (err < 0)
 311                return err;
 312
 313        err = snd_line6_new_midi(line6midi);
 314        if (err < 0)
 315                return err;
 316
 317        init_waitqueue_head(&line6midi->send_wait);
 318        spin_lock_init(&line6midi->send_urb_lock);
 319        spin_lock_init(&line6midi->midi_transmit_lock);
 320        return 0;
 321}
 322