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         bool check_resched = !in_atomic();
 167
 168         if (up) {
 169                 vmidi->trigger = 1;
 170                 if (vmidi->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH &&
 171                     !(vmidi->rdev->flags & SNDRV_VIRMIDI_SUBSCRIBE)) {
 172                         while (snd_rawmidi_transmit(substream, buf,
 173                                                     sizeof(buf)) > 0) {
 174                                 /* ignored */
 175                         }
 176                         return;
 177                 }
 178                 spin_lock_irqsave(&substream->runtime->lock, flags);
 179                 if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
 180                         if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
 181                                 goto out;
 182                         vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
 183                 }
 184                 while (1) {
 185                         count = __snd_rawmidi_transmit_peek(substream, buf, sizeof(buf));
 186                         if (count <= 0)
 187                                 break;
 188                         pbuf = buf;
 189                         while (count > 0) {
 190                                 res = snd_midi_event_encode(vmidi->parser, pbuf, count, &vmidi->event);
 191                                 if (res < 0) {
 192                                         snd_midi_event_reset_encode(vmidi->parser);
 193                                         continue;
 194                                 }
 195                                 __snd_rawmidi_transmit_ack(substream, res);
 196                                 pbuf += res;
 197                                 count -= res;
 198                                 if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
 199                                         if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
 200                                                 goto out;
 201                                         vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
 202                                 }
 203                         }
 204                         if (!check_resched)
 205                                 continue;
 206                         /* do temporary unlock & cond_resched() for avoiding
 207                          * CPU soft lockup, which may happen via a write from
 208                          * a huge rawmidi buffer
 209                          */
 210                         spin_unlock_irqrestore(&substream->runtime->lock, flags);
 211                         cond_resched();
 212                         spin_lock_irqsave(&substream->runtime->lock, flags);
 213                 }
 214         out:
 215                 spin_unlock_irqrestore(&substream->runtime->lock, flags);
 216         } else {
 217                 vmidi->trigger = 0;
 218         }
 219 }
 220
 221 /*
 222  * open rawmidi handle for input
 223  */
 224 static int snd_virmidi_input_open(struct snd_rawmidi_substream *substream)
 225 {
 226         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 227         struct snd_rawmidi_runtime *runtime = substream->runtime;
 228         struct snd_virmidi *vmidi;
 229
 230         vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
 231         if (vmidi == NULL)
 232                 return -ENOMEM;
 233         vmidi->substream = substream;
 234         if (snd_midi_event_new(0, &vmidi->parser) < 0) {
 235                 kfree(vmidi);
 236                 return -ENOMEM;
 237         }
 238         vmidi->seq_mode = rdev->seq_mode;
 239         vmidi->client = rdev->client;
 240         vmidi->port = rdev->port;
 241         runtime->private_data = vmidi;
 242         down_write(&rdev->filelist_sem);
 243         write_lock_irq(&rdev->filelist_lock);
 244         list_add_tail(&vmidi->list, &rdev->filelist);
 245         write_unlock_irq(&rdev->filelist_lock);
 246         up_write(&rdev->filelist_sem);
 247         vmidi->rdev = rdev;
 248         return 0;
 249 }
 250
 251 /*
 252  * open rawmidi handle for output
 253  */
 254 static int snd_virmidi_output_open(struct snd_rawmidi_substream *substream)
 255 {
 256         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 257         struct snd_rawmidi_runtime *runtime = substream->runtime;
 258         struct snd_virmidi *vmidi;
 259
 260         vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
 261         if (vmidi == NULL)
 262                 return -ENOMEM;
 263         vmidi->substream = substream;
 264         if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &vmidi->parser) < 0) {
 265                 kfree(vmidi);
 266                 return -ENOMEM;
 267         }
 268         vmidi->seq_mode = rdev->seq_mode;
 269         vmidi->client = rdev->client;
 270         vmidi->port = rdev->port;
 271         snd_virmidi_init_event(vmidi, &vmidi->event);
 272         vmidi->rdev = rdev;
 273         runtime->private_data = vmidi;
 274         return 0;
 275 }
 276
 277 /*
 278  * close rawmidi handle for input
 279  */
 280 static int snd_virmidi_input_close(struct snd_rawmidi_substream *substream)
 281 {
 282         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 283         struct snd_virmidi *vmidi = substream->runtime->private_data;
 284
 285         down_write(&rdev->filelist_sem);
 286         write_lock_irq(&rdev->filelist_lock);
 287         list_del(&vmidi->list);
 288         write_unlock_irq(&rdev->filelist_lock);
 289         up_write(&rdev->filelist_sem);
 290         snd_midi_event_free(vmidi->parser);
 291         substream->runtime->private_data = NULL;
 292         kfree(vmidi);
 293         return 0;
 294 }
 295
 296 /*
 297  * close rawmidi handle for output
 298  */
 299 static int snd_virmidi_output_close(struct snd_rawmidi_substream *substream)
 300 {
 301         struct snd_virmidi *vmidi = substream->runtime->private_data;
 302         snd_midi_event_free(vmidi->parser);
 303         substream->runtime->private_data = NULL;
 304         kfree(vmidi);
 305         return 0;
 306 }
 307
 308 /*
 309  * subscribe callback - allow output to rawmidi device
 310  */
 311 static int snd_virmidi_subscribe(void *private_data,
 312                                  struct snd_seq_port_subscribe *info)
 313 {
 314         struct snd_virmidi_dev *rdev;
 315
 316         rdev = private_data;
 317         if (!try_module_get(rdev->card->module))
 318                 return -EFAULT;
 319         rdev->flags |= SNDRV_VIRMIDI_SUBSCRIBE;
 320         return 0;
 321 }
 322
 323 /*
 324  * unsubscribe callback - disallow output to rawmidi device
 325  */
 326 static int snd_virmidi_unsubscribe(void *private_data,
 327                                    struct snd_seq_port_subscribe *info)
 328 {
 329         struct snd_virmidi_dev *rdev;
 330
 331         rdev = private_data;
 332         rdev->flags &= ~SNDRV_VIRMIDI_SUBSCRIBE;
 333         module_put(rdev->card->module);
 334         return 0;
 335 }
 336
 337
 338 /*
 339  * use callback - allow input to rawmidi device
 340  */
 341 static int snd_virmidi_use(void *private_data,
 342                            struct snd_seq_port_subscribe *info)
 343 {
 344         struct snd_virmidi_dev *rdev;
 345
 346         rdev = private_data;
 347         if (!try_module_get(rdev->card->module))
 348                 return -EFAULT;
 349         rdev->flags |= SNDRV_VIRMIDI_USE;
 350         return 0;
 351 }
 352
 353 /*
 354  * unuse callback - disallow input to rawmidi device
 355  */
 356 static int snd_virmidi_unuse(void *private_data,
 357                              struct snd_seq_port_subscribe *info)
 358 {
 359         struct snd_virmidi_dev *rdev;
 360
 361         rdev = private_data;
 362         rdev->flags &= ~SNDRV_VIRMIDI_USE;
 363         module_put(rdev->card->module);
 364         return 0;
 365 }
 366
 367
 368 /*
 369  *  Register functions
 370  */
 371
 372 static const struct snd_rawmidi_ops snd_virmidi_input_ops = {
 373         .open = snd_virmidi_input_open,
 374         .close = snd_virmidi_input_close,
 375         .trigger = snd_virmidi_input_trigger,
 376 };
 377
 378 static const struct snd_rawmidi_ops snd_virmidi_output_ops = {
 379         .open = snd_virmidi_output_open,
 380         .close = snd_virmidi_output_close,
 381         .trigger = snd_virmidi_output_trigger,
 382 };
 383
 384 /*
 385  * create a sequencer client and a port
 386  */
 387 static int snd_virmidi_dev_attach_seq(struct snd_virmidi_dev *rdev)
 388 {
 389         int client;
 390         struct snd_seq_port_callback pcallbacks;
 391         struct snd_seq_port_info *pinfo;
 392         int err;
 393
 394         if (rdev->client >= 0)
 395                 return 0;
 396
 397         pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
 398         if (!pinfo) {
 399                 err = -ENOMEM;
 400                 goto __error;
 401         }
 402
 403         client = snd_seq_create_kernel_client(rdev->card, rdev->device,
 404                                               "%s %d-%d", rdev->rmidi->name,
 405                                               rdev->card->number,
 406                                               rdev->device);
 407         if (client < 0) {
 408                 err = client;
 409                 goto __error;
 410         }
 411         rdev->client = client;
 412
 413         /* create a port */
 414         pinfo->addr.client = client;
 415         sprintf(pinfo->name, "VirMIDI %d-%d", rdev->card->number, rdev->device);
 416         /* set all capabilities */
 417         pinfo->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
 418         pinfo->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
 419         pinfo->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
 420         pinfo->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
 421                 | SNDRV_SEQ_PORT_TYPE_SOFTWARE
 422                 | SNDRV_SEQ_PORT_TYPE_PORT;
 423         pinfo->midi_channels = 16;
 424         memset(&pcallbacks, 0, sizeof(pcallbacks));
 425         pcallbacks.owner = THIS_MODULE;
 426         pcallbacks.private_data = rdev;
 427         pcallbacks.subscribe = snd_virmidi_subscribe;
 428         pcallbacks.unsubscribe = snd_virmidi_unsubscribe;
 429         pcallbacks.use = snd_virmidi_use;
 430         pcallbacks.unuse = snd_virmidi_unuse;
 431         pcallbacks.event_input = snd_virmidi_event_input;
 432         pinfo->kernel = &pcallbacks;
 433         err = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, pinfo);
 434         if (err < 0) {
 435                 snd_seq_delete_kernel_client(client);
 436                 rdev->client = -1;
 437                 goto __error;
 438         }
 439
 440         rdev->port = pinfo->addr.port;
 441         err = 0; /* success */
 442
 443  __error:
 444         kfree(pinfo);
 445         return err;
 446 }
 447
 448
 449 /*
 450  * release the sequencer client
 451  */
 452 static void snd_virmidi_dev_detach_seq(struct snd_virmidi_dev *rdev)
 453 {
 454         if (rdev->client >= 0) {
 455                 snd_seq_delete_kernel_client(rdev->client);
 456                 rdev->client = -1;
 457         }
 458 }
 459
 460 /*
 461  * register the device
 462  */
 463 static int snd_virmidi_dev_register(struct snd_rawmidi *rmidi)
 464 {
 465         struct snd_virmidi_dev *rdev = rmidi->private_data;
 466         int err;
 467
 468         switch (rdev->seq_mode) {
 469         case SNDRV_VIRMIDI_SEQ_DISPATCH:
 470                 err = snd_virmidi_dev_attach_seq(rdev);
 471                 if (err < 0)
 472                         return err;
 473                 break;
 474         case SNDRV_VIRMIDI_SEQ_ATTACH:
 475                 if (rdev->client == 0)
 476                         return -EINVAL;
 477                 /* should check presence of port more strictly.. */
 478                 break;
 479         default:
 480                 pr_err("ALSA: seq_virmidi: seq_mode is not set: %d\n", rdev->seq_mode);
 481                 return -EINVAL;
 482         }
 483         return 0;
 484 }
 485
 486
 487 /*
 488  * unregister the device
 489  */
 490 static int snd_virmidi_dev_unregister(struct snd_rawmidi *rmidi)
 491 {
 492         struct snd_virmidi_dev *rdev = rmidi->private_data;
 493
 494         if (rdev->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH)
 495                 snd_virmidi_dev_detach_seq(rdev);
 496         return 0;
 497 }
 498
 499 /*
 500  *
 501  */
 502 static const struct snd_rawmidi_global_ops snd_virmidi_global_ops = {
 503         .dev_register = snd_virmidi_dev_register,
 504         .dev_unregister = snd_virmidi_dev_unregister,
 505 };
 506
 507 /*
 508  * free device
 509  */
 510 static void snd_virmidi_free(struct snd_rawmidi *rmidi)
 511 {
 512         struct snd_virmidi_dev *rdev = rmidi->private_data;
 513         kfree(rdev);
 514 }
 515
 516 /*
 517  * create a new device
 518  *
 519  */
 520 /* exported */
 521 int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi)
 522 {
 523         struct snd_rawmidi *rmidi;
 524         struct snd_virmidi_dev *rdev;
 525         int err;
 526
 527         *rrmidi = NULL;
 528         if ((err = snd_rawmidi_new(card, "VirMidi", device,
 529                                    16,  /* may be configurable */
 530                                    16,  /* may be configurable */
 531                                    &rmidi)) < 0)
 532                 return err;
 533         strcpy(rmidi->name, rmidi->id);
 534         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
 535         if (rdev == NULL) {
 536                 snd_device_free(card, rmidi);
 537                 return -ENOMEM;
 538         }
 539         rdev->card = card;
 540         rdev->rmidi = rmidi;
 541         rdev->device = device;
 542         rdev->client = -1;
 543         init_rwsem(&rdev->filelist_sem);
 544         rwlock_init(&rdev->filelist_lock);
 545         INIT_LIST_HEAD(&rdev->filelist);
 546         rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
 547         rmidi->private_data = rdev;
 548         rmidi->private_free = snd_virmidi_free;
 549         rmidi->ops = &snd_virmidi_global_ops;
 550         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_virmidi_input_ops);
 551         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_virmidi_output_ops);
 552         rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
 553                             SNDRV_RAWMIDI_INFO_OUTPUT |
 554                             SNDRV_RAWMIDI_INFO_DUPLEX;
 555         *rrmidi = rmidi;
 556         return 0;
 557 }
 558 EXPORT_SYMBOL(snd_virmidi_new);
 559
 560 /*
 561  *  ENTRY functions
 562  */
 563
 564 static int __init alsa_virmidi_init(void)
 565 {
 566         return 0;
 567 }
 568
 569 static void __exit alsa_virmidi_exit(void)
 570 {
 571 }
 572
 573 module_init(alsa_virmidi_init)
 574 module_exit(alsa_virmidi_exit)