sound/core/seq/seq_virmidi.c

   1 /*
   2  *  Virtual Raw MIDI client on Sequencer
   3  *
   4  *  Copyright (c) 2000 by Takashi Iwai <tiwai@suse.de>,
   5  *                        Jaroslav Kysela <perex@perex.cz>
   6  *
   7  *   This program is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU General Public License as published by
   9  *   the Free Software Foundation; either version 2 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  20  *
  21  */
  22
  23 /*
  24  * Virtual Raw MIDI client
  25  *
  26  * The virtual rawmidi client is a sequencer client which associate
  27  * a rawmidi device file.  The created rawmidi device file can be
  28  * accessed as a normal raw midi, but its MIDI source and destination
  29  * are arbitrary.  For example, a user-client software synth connected
  30  * to this port can be used as a normal midi device as well.
  31  *
  32  * The virtual rawmidi device accepts also multiple opens.  Each file
  33  * has its own input buffer, so that no conflict would occur.  The drain
  34  * of input/output buffer acts only to the local buffer.
  35  *
  36  */
  37
  38 #include <linux/init.h>
  39 #include <linux/wait.h>
  40 #include <linux/module.h>
  41 #include <linux/slab.h>
  42 #include <sound/core.h>
  43 #include <sound/rawmidi.h>
  44 #include <sound/info.h>
  45 #include <sound/control.h>
  46 #include <sound/minors.h>
  47 #include <sound/seq_kernel.h>
  48 #include <sound/seq_midi_event.h>
  49 #include <sound/seq_virmidi.h>
  50
  51 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
  52 MODULE_DESCRIPTION("Virtual Raw MIDI client on Sequencer");
  53 MODULE_LICENSE("GPL");
  54
  55 /*
  56  * initialize an event record
  57  */
  58 static void snd_virmidi_init_event(struct snd_virmidi *vmidi,
  59                                    struct snd_seq_event *ev)
  60 {
  61         memset(ev, 0, sizeof(*ev));
  62         ev->source.port = vmidi->port;
  63         switch (vmidi->seq_mode) {
  64         case SNDRV_VIRMIDI_SEQ_DISPATCH:
  65                 ev->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
  66                 break;
  67         case SNDRV_VIRMIDI_SEQ_ATTACH:
  68                 /* FIXME: source and destination are same - not good.. */
  69                 ev->dest.client = vmidi->client;
  70                 ev->dest.port = vmidi->port;
  71                 break;
  72         }
  73         ev->type = SNDRV_SEQ_EVENT_NONE;
  74 }
  75
  76 /*
  77  * decode input event and put to read buffer of each opened file
  78  */
  79 static int snd_virmidi_dev_receive_event(struct snd_virmidi_dev *rdev,
  80                                          struct snd_seq_event *ev,
  81                                          bool atomic)
  82 {
  83         struct snd_virmidi *vmidi;
  84         unsigned char msg[4];
  85         int len;
  86
  87         if (atomic)
  88                 read_lock(&rdev->filelist_lock);
  89         else
  90                 down_read(&rdev->filelist_sem);
  91         list_for_each_entry(vmidi, &rdev->filelist, list) {
  92                 if (!vmidi->trigger)
  93                         continue;
  94                 if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {
  95                         if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
  96                                 continue;
  97                         snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)snd_rawmidi_receive, vmidi->substream);
  98                 } else {
  99                         len = snd_midi_event_decode(vmidi->parser, msg, sizeof(msg), ev);
 100                         if (len > 0)
 101                                 snd_rawmidi_receive(vmidi->substream, msg, len);
 102                 }
 103         }
 104         if (atomic)
 105                 read_unlock(&rdev->filelist_lock);
 106         else
 107                 up_read(&rdev->filelist_sem);
 108
 109         return 0;
 110 }
 111
 112 /*
 113  * receive an event from the remote virmidi port
 114  *
 115  * for rawmidi inputs, you can call this function from the event
 116  * handler of a remote port which is attached to the virmidi via
 117  * SNDRV_VIRMIDI_SEQ_ATTACH.
 118  */
 119 #if 0
 120 int snd_virmidi_receive(struct snd_rawmidi *rmidi, struct snd_seq_event *ev)
 121 {
 122         struct snd_virmidi_dev *rdev;
 123
 124         rdev = rmidi->private_data;
 125         return snd_virmidi_dev_receive_event(rdev, ev, true);
 126 }
 127 #endif  /*  0  */
 128
 129 /*
 130  * event handler of virmidi port
 131  */
 132 static int snd_virmidi_event_input(struct snd_seq_event *ev, int direct,
 133                                    void *private_data, int atomic, int hop)
 134 {
 135         struct snd_virmidi_dev *rdev;
 136
 137         rdev = private_data;
 138         if (!(rdev->flags & SNDRV_VIRMIDI_USE))
 139                 return 0; /* ignored */
 140         return snd_virmidi_dev_receive_event(rdev, ev, atomic);
 141 }
 142
 143 /*
 144  * trigger rawmidi stream for input
 145  */
 146 static void snd_virmidi_input_trigger(struct snd_rawmidi_substream *substream, int up)
 147 {
 148         struct snd_virmidi *vmidi = substream->runtime->private_data;
 149
 150         if (up) {
 151                 vmidi->trigger = 1;
 152         } else {
 153                 vmidi->trigger = 0;
 154         }
 155 }
 156
 157 /*
 158  * trigger rawmidi stream for output
 159  */
 160 static void snd_virmidi_output_trigger(struct snd_rawmidi_substream *substream, int up)
 161 {
 162         struct snd_virmidi *vmidi = substream->runtime->private_data;
 163         int count, res;
 164         unsigned char buf[32], *pbuf;
 165         unsigned long flags;
 166
 167         if (up) {
 168                 vmidi->trigger = 1;
 169                 if (vmidi->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH &&
 170                     !(vmidi->rdev->flags & SNDRV_VIRMIDI_SUBSCRIBE)) {
 171                         while (snd_rawmidi_transmit(substream, buf,
 172                                                     sizeof(buf)) > 0) {
 173                                 /* ignored */
 174                         }
 175                         return;
 176                 }
 177                 spin_lock_irqsave(&substream->runtime->lock, flags);
 178                 if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
 179                         if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
 180                                 goto out;
 181                         vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
 182                 }
 183                 while (1) {
 184                         count = __snd_rawmidi_transmit_peek(substream, buf, sizeof(buf));
 185                         if (count <= 0)
 186                                 break;
 187                         pbuf = buf;
 188                         while (count > 0) {
 189                                 res = snd_midi_event_encode(vmidi->parser, pbuf, count, &vmidi->event);
 190                                 if (res < 0) {
 191                                         snd_midi_event_reset_encode(vmidi->parser);
 192                                         continue;
 193                                 }
 194                                 __snd_rawmidi_transmit_ack(substream, res);
 195                                 pbuf += res;
 196                                 count -= res;
 197                                 if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
 198                                         if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
 199                                                 goto out;
 200                                         vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
 201                                 }
 202                         }
 203                 }
 204         out:
 205                 spin_unlock_irqrestore(&substream->runtime->lock, flags);
 206         } else {
 207                 vmidi->trigger = 0;
 208         }
 209 }
 210
 211 /*
 212  * open rawmidi handle for input
 213  */
 214 static int snd_virmidi_input_open(struct snd_rawmidi_substream *substream)
 215 {
 216         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 217         struct snd_rawmidi_runtime *runtime = substream->runtime;
 218         struct snd_virmidi *vmidi;
 219
 220         vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
 221         if (vmidi == NULL)
 222                 return -ENOMEM;
 223         vmidi->substream = substream;
 224         if (snd_midi_event_new(0, &vmidi->parser) < 0) {
 225                 kfree(vmidi);
 226                 return -ENOMEM;
 227         }
 228         vmidi->seq_mode = rdev->seq_mode;
 229         vmidi->client = rdev->client;
 230         vmidi->port = rdev->port;
 231         runtime->private_data = vmidi;
 232         down_write(&rdev->filelist_sem);
 233         write_lock_irq(&rdev->filelist_lock);
 234         list_add_tail(&vmidi->list, &rdev->filelist);
 235         write_unlock_irq(&rdev->filelist_lock);
 236         up_write(&rdev->filelist_sem);
 237         vmidi->rdev = rdev;
 238         return 0;
 239 }
 240
 241 /*
 242  * open rawmidi handle for output
 243  */
 244 static int snd_virmidi_output_open(struct snd_rawmidi_substream *substream)
 245 {
 246         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 247         struct snd_rawmidi_runtime *runtime = substream->runtime;
 248         struct snd_virmidi *vmidi;
 249
 250         vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
 251         if (vmidi == NULL)
 252                 return -ENOMEM;
 253         vmidi->substream = substream;
 254         if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &vmidi->parser) < 0) {
 255                 kfree(vmidi);
 256                 return -ENOMEM;
 257         }
 258         vmidi->seq_mode = rdev->seq_mode;
 259         vmidi->client = rdev->client;
 260         vmidi->port = rdev->port;
 261         snd_virmidi_init_event(vmidi, &vmidi->event);
 262         vmidi->rdev = rdev;
 263         runtime->private_data = vmidi;
 264         return 0;
 265 }
 266
 267 /*
 268  * close rawmidi handle for input
 269  */
 270 static int snd_virmidi_input_close(struct snd_rawmidi_substream *substream)
 271 {
 272         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 273         struct snd_virmidi *vmidi = substream->runtime->private_data;
 274
 275         down_write(&rdev->filelist_sem);
 276         write_lock_irq(&rdev->filelist_lock);
 277         list_del(&vmidi->list);
 278         write_unlock_irq(&rdev->filelist_lock);
 279         up_write(&rdev->filelist_sem);
 280         snd_midi_event_free(vmidi->parser);
 281         substream->runtime->private_data = NULL;
 282         kfree(vmidi);
 283         return 0;
 284 }
 285
 286 /*
 287  * close rawmidi handle for output
 288  */
 289 static int snd_virmidi_output_close(struct snd_rawmidi_substream *substream)
 290 {
 291         struct snd_virmidi *vmidi = substream->runtime->private_data;
 292         snd_midi_event_free(vmidi->parser);
 293         substream->runtime->private_data = NULL;
 294         kfree(vmidi);
 295         return 0;
 296 }
 297
 298 /*
 299  * subscribe callback - allow output to rawmidi device
 300  */
 301 static int snd_virmidi_subscribe(void *private_data,
 302                                  struct snd_seq_port_subscribe *info)
 303 {
 304         struct snd_virmidi_dev *rdev;
 305
 306         rdev = private_data;
 307         if (!try_module_get(rdev->card->module))
 308                 return -EFAULT;
 309         rdev->flags |= SNDRV_VIRMIDI_SUBSCRIBE;
 310         return 0;
 311 }
 312
 313 /*
 314  * unsubscribe callback - disallow output to rawmidi device
 315  */
 316 static int snd_virmidi_unsubscribe(void *private_data,
 317                                    struct snd_seq_port_subscribe *info)
 318 {
 319         struct snd_virmidi_dev *rdev;
 320
 321         rdev = private_data;
 322         rdev->flags &= ~SNDRV_VIRMIDI_SUBSCRIBE;
 323         module_put(rdev->card->module);
 324         return 0;
 325 }
 326
 327
 328 /*
 329  * use callback - allow input to rawmidi device
 330  */
 331 static int snd_virmidi_use(void *private_data,
 332                            struct snd_seq_port_subscribe *info)
 333 {
 334         struct snd_virmidi_dev *rdev;
 335
 336         rdev = private_data;
 337         if (!try_module_get(rdev->card->module))
 338                 return -EFAULT;
 339         rdev->flags |= SNDRV_VIRMIDI_USE;
 340         return 0;
 341 }
 342
 343 /*
 344  * unuse callback - disallow input to rawmidi device
 345  */
 346 static int snd_virmidi_unuse(void *private_data,
 347                              struct snd_seq_port_subscribe *info)
 348 {
 349         struct snd_virmidi_dev *rdev;
 350
 351         rdev = private_data;
 352         rdev->flags &= ~SNDRV_VIRMIDI_USE;
 353         module_put(rdev->card->module);
 354         return 0;
 355 }
 356
 357
 358 /*
 359  *  Register functions
 360  */
 361
 362 static const struct snd_rawmidi_ops snd_virmidi_input_ops = {
 363         .open = snd_virmidi_input_open,
 364         .close = snd_virmidi_input_close,
 365         .trigger = snd_virmidi_input_trigger,
 366 };
 367
 368 static const struct snd_rawmidi_ops snd_virmidi_output_ops = {
 369         .open = snd_virmidi_output_open,
 370         .close = snd_virmidi_output_close,
 371         .trigger = snd_virmidi_output_trigger,
 372 };
 373
 374 /*
 375  * create a sequencer client and a port
 376  */
 377 static int snd_virmidi_dev_attach_seq(struct snd_virmidi_dev *rdev)
 378 {
 379         int client;
 380         struct snd_seq_port_callback pcallbacks;
 381         struct snd_seq_port_info *pinfo;
 382         int err;
 383
 384         if (rdev->client >= 0)
 385                 return 0;
 386
 387         pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
 388         if (!pinfo) {
 389                 err = -ENOMEM;
 390                 goto __error;
 391         }
 392
 393         client = snd_seq_create_kernel_client(rdev->card, rdev->device,
 394                                               "%s %d-%d", rdev->rmidi->name,
 395                                               rdev->card->number,
 396                                               rdev->device);
 397         if (client < 0) {
 398                 err = client;
 399                 goto __error;
 400         }
 401         rdev->client = client;
 402
 403         /* create a port */
 404         pinfo->addr.client = client;
 405         sprintf(pinfo->name, "VirMIDI %d-%d", rdev->card->number, rdev->device);
 406         /* set all capabilities */
 407         pinfo->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
 408         pinfo->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
 409         pinfo->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
 410         pinfo->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
 411                 | SNDRV_SEQ_PORT_TYPE_SOFTWARE
 412                 | SNDRV_SEQ_PORT_TYPE_PORT;
 413         pinfo->midi_channels = 16;
 414         memset(&pcallbacks, 0, sizeof(pcallbacks));
 415         pcallbacks.owner = THIS_MODULE;
 416         pcallbacks.private_data = rdev;
 417         pcallbacks.subscribe = snd_virmidi_subscribe;
 418         pcallbacks.unsubscribe = snd_virmidi_unsubscribe;
 419         pcallbacks.use = snd_virmidi_use;
 420         pcallbacks.unuse = snd_virmidi_unuse;
 421         pcallbacks.event_input = snd_virmidi_event_input;
 422         pinfo->kernel = &pcallbacks;
 423         err = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, pinfo);
 424         if (err < 0) {
 425                 snd_seq_delete_kernel_client(client);
 426                 rdev->client = -1;
 427                 goto __error;
 428         }
 429
 430         rdev->port = pinfo->addr.port;
 431         err = 0; /* success */
 432
 433  __error:
 434         kfree(pinfo);
 435         return err;
 436 }
 437
 438
 439 /*
 440  * release the sequencer client
 441  */
 442 static void snd_virmidi_dev_detach_seq(struct snd_virmidi_dev *rdev)
 443 {
 444         if (rdev->client >= 0) {
 445                 snd_seq_delete_kernel_client(rdev->client);
 446                 rdev->client = -1;
 447         }
 448 }
 449
 450 /*
 451  * register the device
 452  */
 453 static int snd_virmidi_dev_register(struct snd_rawmidi *rmidi)
 454 {
 455         struct snd_virmidi_dev *rdev = rmidi->private_data;
 456         int err;
 457
 458         switch (rdev->seq_mode) {
 459         case SNDRV_VIRMIDI_SEQ_DISPATCH:
 460                 err = snd_virmidi_dev_attach_seq(rdev);
 461                 if (err < 0)
 462                         return err;
 463                 break;
 464         case SNDRV_VIRMIDI_SEQ_ATTACH:
 465                 if (rdev->client == 0)
 466                         return -EINVAL;
 467                 /* should check presence of port more strictly.. */
 468                 break;
 469         default:
 470                 pr_err("ALSA: seq_virmidi: seq_mode is not set: %d\n", rdev->seq_mode);
 471                 return -EINVAL;
 472         }
 473         return 0;
 474 }
 475
 476
 477 /*
 478  * unregister the device
 479  */
 480 static int snd_virmidi_dev_unregister(struct snd_rawmidi *rmidi)
 481 {
 482         struct snd_virmidi_dev *rdev = rmidi->private_data;
 483
 484         if (rdev->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH)
 485                 snd_virmidi_dev_detach_seq(rdev);
 486         return 0;
 487 }
 488
 489 /*
 490  *
 491  */
 492 static const struct snd_rawmidi_global_ops snd_virmidi_global_ops = {
 493         .dev_register = snd_virmidi_dev_register,
 494         .dev_unregister = snd_virmidi_dev_unregister,
 495 };
 496
 497 /*
 498  * free device
 499  */
 500 static void snd_virmidi_free(struct snd_rawmidi *rmidi)
 501 {
 502         struct snd_virmidi_dev *rdev = rmidi->private_data;
 503         kfree(rdev);
 504 }
 505
 506 /*
 507  * create a new device
 508  *
 509  */
 510 /* exported */
 511 int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi)
 512 {
 513         struct snd_rawmidi *rmidi;
 514         struct snd_virmidi_dev *rdev;
 515         int err;
 516
 517         *rrmidi = NULL;
 518         if ((err = snd_rawmidi_new(card, "VirMidi", device,
 519                                    16,  /* may be configurable */
 520                                    16,  /* may be configurable */
 521                                    &rmidi)) < 0)
 522                 return err;
 523         strcpy(rmidi->name, rmidi->id);
 524         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
 525         if (rdev == NULL) {
 526                 snd_device_free(card, rmidi);
 527                 return -ENOMEM;
 528         }
 529         rdev->card = card;
 530         rdev->rmidi = rmidi;
 531         rdev->device = device;
 532         rdev->client = -1;
 533         init_rwsem(&rdev->filelist_sem);
 534         rwlock_init(&rdev->filelist_lock);
 535         INIT_LIST_HEAD(&rdev->filelist);
 536         rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
 537         rmidi->private_data = rdev;
 538         rmidi->private_free = snd_virmidi_free;
 539         rmidi->ops = &snd_virmidi_global_ops;
 540         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_virmidi_input_ops);
 541         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_virmidi_output_ops);
 542         rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
 543                             SNDRV_RAWMIDI_INFO_OUTPUT |
 544                             SNDRV_RAWMIDI_INFO_DUPLEX;
 545         *rrmidi = rmidi;
 546         return 0;
 547 }
 548 EXPORT_SYMBOL(snd_virmidi_new);
 549
 550 /*
 551  *  ENTRY functions
 552  */
 553
 554 static int __init alsa_virmidi_init(void)
 555 {
 556         return 0;
 557 }
 558
 559 static void __exit alsa_virmidi_exit(void)
 560 {
 561 }
 562
 563 module_init(alsa_virmidi_init)
 564 module_exit(alsa_virmidi_exit)