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