drivers/staging/line6/midi.c

   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
  26 static 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 */
  32 void 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 */
  43 static 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 */
  82 static 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 */
 115 static 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->properties->ep_ctrl_w),
 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
 155 static int line6_midi_output_open(struct snd_rawmidi_substream *substream)
 156 {
 157         return 0;
 158 }
 159
 160 static int line6_midi_output_close(struct snd_rawmidi_substream *substream)
 161 {
 162         return 0;
 163 }
 164
 165 static 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
 181 static 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
 191 static int line6_midi_input_open(struct snd_rawmidi_substream *substream)
 192 {
 193         return 0;
 194 }
 195
 196 static int line6_midi_input_close(struct snd_rawmidi_substream *substream)
 197 {
 198         return 0;
 199 }
 200
 201 static 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
 213 static 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
 220 static 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 */
 229 static void line6_cleanup_midi(struct snd_rawmidi *rmidi)
 230 {
 231 }
 232
 233 /* Create a MIDI device */
 234 static 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 */
 261 static 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 */
 273 int 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_CAP_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 }