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(snd_virmidi_t *vmidi, snd_seq_event_t *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(snd_virmidi_dev_t *rdev, snd_seq_event_t *ev)
  80 {
  81         snd_virmidi_t *vmidi;
  82         struct list_head *list;
  83         unsigned char msg[4];
  84         int len;
  85
  86         read_lock(&rdev->filelist_lock);
  87         list_for_each(list, &rdev->filelist) {
  88                 vmidi = list_entry(list, snd_virmidi_t, list);
  89                 if (!vmidi->trigger)
  90                         continue;
  91                 if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {
  92                         if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
  93                                 continue;
  94                         snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)snd_rawmidi_receive, vmidi->substream);
  95                 } else {
  96                         len = snd_midi_event_decode(vmidi->parser, msg, sizeof(msg), ev);
  97                         if (len > 0)
  98                                 snd_rawmidi_receive(vmidi->substream, msg, len);
  99                 }
 100         }
 101         read_unlock(&rdev->filelist_lock);
 102
 103         return 0;
 104 }
 105
 106 /*
 107  * receive an event from the remote virmidi port
 108  *
 109  * for rawmidi inputs, you can call this function from the event
 110  * handler of a remote port which is attached to the virmidi via
 111  * SNDRV_VIRMIDI_SEQ_ATTACH.
 112  */
 113 #if 0
 114 int snd_virmidi_receive(snd_rawmidi_t *rmidi, snd_seq_event_t *ev)
 115 {
 116         snd_virmidi_dev_t *rdev;
 117
 118         rdev = rmidi->private_data;
 119         return snd_virmidi_dev_receive_event(rdev, ev);
 120 }
 121 #endif  /*  0  */
 122
 123 /*
 124  * event handler of virmidi port
 125  */
 126 static int snd_virmidi_event_input(snd_seq_event_t *ev, int direct,
 127                                    void *private_data, int atomic, int hop)
 128 {
 129         snd_virmidi_dev_t *rdev;
 130
 131         rdev = private_data;
 132         if (!(rdev->flags & SNDRV_VIRMIDI_USE))
 133                 return 0; /* ignored */
 134         return snd_virmidi_dev_receive_event(rdev, ev);
 135 }
 136
 137 /*
 138  * trigger rawmidi stream for input
 139  */
 140 static void snd_virmidi_input_trigger(snd_rawmidi_substream_t * substream, int up)
 141 {
 142         snd_virmidi_t *vmidi = substream->runtime->private_data;
 143
 144         if (up) {
 145                 vmidi->trigger = 1;
 146         } else {
 147                 vmidi->trigger = 0;
 148         }
 149 }
 150
 151 /*
 152  * trigger rawmidi stream for output
 153  */
 154 static void snd_virmidi_output_trigger(snd_rawmidi_substream_t * substream, int up)
 155 {
 156         snd_virmidi_t *vmidi = substream->runtime->private_data;
 157         int count, res;
 158         unsigned char buf[32], *pbuf;
 159
 160         if (up) {
 161                 vmidi->trigger = 1;
 162                 if (vmidi->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH &&
 163                     !(vmidi->rdev->flags & SNDRV_VIRMIDI_SUBSCRIBE)) {
 164                         snd_rawmidi_transmit_ack(substream, substream->runtime->buffer_size - substream->runtime->avail);
 165                         return;         /* ignored */
 166                 }
 167                 if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
 168                         if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, 0, 0) < 0)
 169                                 return;
 170                         vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
 171                 }
 172                 while (1) {
 173                         count = snd_rawmidi_transmit_peek(substream, buf, sizeof(buf));
 174                         if (count <= 0)
 175                                 break;
 176                         pbuf = buf;
 177                         while (count > 0) {
 178                                 res = snd_midi_event_encode(vmidi->parser, pbuf, count, &vmidi->event);
 179                                 if (res < 0) {
 180                                         snd_midi_event_reset_encode(vmidi->parser);
 181                                         continue;
 182                                 }
 183                                 snd_rawmidi_transmit_ack(substream, res);
 184                                 pbuf += res;
 185                                 count -= res;
 186                                 if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
 187                                         if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, 0, 0) < 0)
 188                                                 return;
 189                                         vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
 190                                 }
 191                         }
 192                 }
 193         } else {
 194                 vmidi->trigger = 0;
 195         }
 196 }
 197
 198 /*
 199  * open rawmidi handle for input
 200  */
 201 static int snd_virmidi_input_open(snd_rawmidi_substream_t * substream)
 202 {
 203         snd_virmidi_dev_t *rdev = substream->rmidi->private_data;
 204         snd_rawmidi_runtime_t *runtime = substream->runtime;
 205         snd_virmidi_t *vmidi;
 206         unsigned long flags;
 207
 208         vmidi = kcalloc(1, sizeof(*vmidi), GFP_KERNEL);
 209         if (vmidi == NULL)
 210                 return -ENOMEM;
 211         vmidi->substream = substream;
 212         if (snd_midi_event_new(0, &vmidi->parser) < 0) {
 213                 kfree(vmidi);
 214                 return -ENOMEM;
 215         }
 216         vmidi->seq_mode = rdev->seq_mode;
 217         vmidi->client = rdev->client;
 218         vmidi->port = rdev->port;
 219         runtime->private_data = vmidi;
 220         write_lock_irqsave(&rdev->filelist_lock, flags);
 221         list_add_tail(&vmidi->list, &rdev->filelist);
 222         write_unlock_irqrestore(&rdev->filelist_lock, flags);
 223         vmidi->rdev = rdev;
 224         return 0;
 225 }
 226
 227 /*
 228  * open rawmidi handle for output
 229  */
 230 static int snd_virmidi_output_open(snd_rawmidi_substream_t * substream)
 231 {
 232         snd_virmidi_dev_t *rdev = substream->rmidi->private_data;
 233         snd_rawmidi_runtime_t *runtime = substream->runtime;
 234         snd_virmidi_t *vmidi;
 235
 236         vmidi = kcalloc(1, sizeof(*vmidi), GFP_KERNEL);
 237         if (vmidi == NULL)
 238                 return -ENOMEM;
 239         vmidi->substream = substream;
 240         if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &vmidi->parser) < 0) {
 241                 kfree(vmidi);
 242                 return -ENOMEM;
 243         }
 244         vmidi->seq_mode = rdev->seq_mode;
 245         vmidi->client = rdev->client;
 246         vmidi->port = rdev->port;
 247         snd_virmidi_init_event(vmidi, &vmidi->event);
 248         vmidi->rdev = rdev;
 249         runtime->private_data = vmidi;
 250         return 0;
 251 }
 252
 253 /*
 254  * close rawmidi handle for input
 255  */
 256 static int snd_virmidi_input_close(snd_rawmidi_substream_t * substream)
 257 {
 258         snd_virmidi_t *vmidi = substream->runtime->private_data;
 259         snd_midi_event_free(vmidi->parser);
 260         list_del(&vmidi->list);
 261         substream->runtime->private_data = NULL;
 262         kfree(vmidi);
 263         return 0;
 264 }
 265
 266 /*
 267  * close rawmidi handle for output
 268  */
 269 static int snd_virmidi_output_close(snd_rawmidi_substream_t * substream)
 270 {
 271         snd_virmidi_t *vmidi = substream->runtime->private_data;
 272         snd_midi_event_free(vmidi->parser);
 273         substream->runtime->private_data = NULL;
 274         kfree(vmidi);
 275         return 0;
 276 }
 277
 278 /*
 279  * subscribe callback - allow output to rawmidi device
 280  */
 281 static int snd_virmidi_subscribe(void *private_data, snd_seq_port_subscribe_t *info)
 282 {
 283         snd_virmidi_dev_t *rdev;
 284
 285         rdev = private_data;
 286         if (!try_module_get(rdev->card->module))
 287                 return -EFAULT;
 288         rdev->flags |= SNDRV_VIRMIDI_SUBSCRIBE;
 289         return 0;
 290 }
 291
 292 /*
 293  * unsubscribe callback - disallow output to rawmidi device
 294  */
 295 static int snd_virmidi_unsubscribe(void *private_data, snd_seq_port_subscribe_t *info)
 296 {
 297         snd_virmidi_dev_t *rdev;
 298
 299         rdev = private_data;
 300         rdev->flags &= ~SNDRV_VIRMIDI_SUBSCRIBE;
 301         module_put(rdev->card->module);
 302         return 0;
 303 }
 304
 305
 306 /*
 307  * use callback - allow input to rawmidi device
 308  */
 309 static int snd_virmidi_use(void *private_data, snd_seq_port_subscribe_t *info)
 310 {
 311         snd_virmidi_dev_t *rdev;
 312
 313         rdev = private_data;
 314         if (!try_module_get(rdev->card->module))
 315                 return -EFAULT;
 316         rdev->flags |= SNDRV_VIRMIDI_USE;
 317         return 0;
 318 }
 319
 320 /*
 321  * unuse callback - disallow input to rawmidi device
 322  */
 323 static int snd_virmidi_unuse(void *private_data, snd_seq_port_subscribe_t *info)
 324 {
 325         snd_virmidi_dev_t *rdev;
 326
 327         rdev = private_data;
 328         rdev->flags &= ~SNDRV_VIRMIDI_USE;
 329         module_put(rdev->card->module);
 330         return 0;
 331 }
 332
 333
 334 /*
 335  *  Register functions
 336  */
 337
 338 static snd_rawmidi_ops_t snd_virmidi_input_ops = {
 339         .open = snd_virmidi_input_open,
 340         .close = snd_virmidi_input_close,
 341         .trigger = snd_virmidi_input_trigger,
 342 };
 343
 344 static snd_rawmidi_ops_t snd_virmidi_output_ops = {
 345         .open = snd_virmidi_output_open,
 346         .close = snd_virmidi_output_close,
 347         .trigger = snd_virmidi_output_trigger,
 348 };
 349
 350 /*
 351  * create a sequencer client and a port
 352  */
 353 static int snd_virmidi_dev_attach_seq(snd_virmidi_dev_t *rdev)
 354 {
 355         int client;
 356         snd_seq_client_callback_t callbacks;
 357         snd_seq_port_callback_t pcallbacks;
 358         snd_seq_client_info_t *info;
 359         snd_seq_port_info_t *pinfo;
 360         int err;
 361
 362         if (rdev->client >= 0)
 363                 return 0;
 364
 365         info = kmalloc(sizeof(*info), GFP_KERNEL);
 366         pinfo = kmalloc(sizeof(*pinfo), GFP_KERNEL);
 367         if (! info || ! pinfo) {
 368                 err = -ENOMEM;
 369                 goto __error;
 370         }
 371
 372         memset(&callbacks, 0, sizeof(callbacks));
 373         callbacks.private_data = rdev;
 374         callbacks.allow_input = 1;
 375         callbacks.allow_output = 1;
 376         client = snd_seq_create_kernel_client(rdev->card, rdev->device, &callbacks);
 377         if (client < 0) {
 378                 err = client;
 379                 goto __error;
 380         }
 381         rdev->client = client;
 382
 383         /* set client name */
 384         memset(info, 0, sizeof(*info));
 385         info->client = client;
 386         info->type = KERNEL_CLIENT;
 387         sprintf(info->name, "%s %d-%d", rdev->rmidi->name, rdev->card->number, rdev->device);
 388         snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_SET_CLIENT_INFO, info);
 389
 390         /* create a port */
 391         memset(pinfo, 0, sizeof(*pinfo));
 392         pinfo->addr.client = client;
 393         sprintf(pinfo->name, "VirMIDI %d-%d", rdev->card->number, rdev->device);
 394         /* set all capabilities */
 395         pinfo->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
 396         pinfo->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
 397         pinfo->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
 398         pinfo->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC;
 399         pinfo->midi_channels = 16;
 400         memset(&pcallbacks, 0, sizeof(pcallbacks));
 401         pcallbacks.owner = THIS_MODULE;
 402         pcallbacks.private_data = rdev;
 403         pcallbacks.subscribe = snd_virmidi_subscribe;
 404         pcallbacks.unsubscribe = snd_virmidi_unsubscribe;
 405         pcallbacks.use = snd_virmidi_use;
 406         pcallbacks.unuse = snd_virmidi_unuse;
 407         pcallbacks.event_input = snd_virmidi_event_input;
 408         pinfo->kernel = &pcallbacks;
 409         err = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, pinfo);
 410         if (err < 0) {
 411                 snd_seq_delete_kernel_client(client);
 412                 rdev->client = -1;
 413                 goto __error;
 414         }
 415
 416         rdev->port = pinfo->addr.port;
 417         err = 0; /* success */
 418
 419  __error:
 420         kfree(info);
 421         kfree(pinfo);
 422         return err;
 423 }
 424
 425
 426 /*
 427  * release the sequencer client
 428  */
 429 static void snd_virmidi_dev_detach_seq(snd_virmidi_dev_t *rdev)
 430 {
 431         if (rdev->client >= 0) {
 432                 snd_seq_delete_kernel_client(rdev->client);
 433                 rdev->client = -1;
 434         }
 435 }
 436
 437 /*
 438  * register the device
 439  */
 440 static int snd_virmidi_dev_register(snd_rawmidi_t *rmidi)
 441 {
 442         snd_virmidi_dev_t *rdev = rmidi->private_data;
 443         int err;
 444
 445         switch (rdev->seq_mode) {
 446         case SNDRV_VIRMIDI_SEQ_DISPATCH:
 447                 err = snd_virmidi_dev_attach_seq(rdev);
 448                 if (err < 0)
 449                         return err;
 450                 break;
 451         case SNDRV_VIRMIDI_SEQ_ATTACH:
 452                 if (rdev->client == 0)
 453                         return -EINVAL;
 454                 /* should check presence of port more strictly.. */
 455                 break;
 456         default:
 457                 snd_printk(KERN_ERR "seq_mode is not set: %d\n", rdev->seq_mode);
 458                 return -EINVAL;
 459         }
 460         return 0;
 461 }
 462
 463
 464 /*
 465  * unregister the device
 466  */
 467 static int snd_virmidi_dev_unregister(snd_rawmidi_t *rmidi)
 468 {
 469         snd_virmidi_dev_t *rdev = rmidi->private_data;
 470
 471         if (rdev->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH)
 472                 snd_virmidi_dev_detach_seq(rdev);
 473         return 0;
 474 }
 475
 476 /*
 477  *
 478  */
 479 static snd_rawmidi_global_ops_t snd_virmidi_global_ops = {
 480         .dev_register = snd_virmidi_dev_register,
 481         .dev_unregister = snd_virmidi_dev_unregister,
 482 };
 483
 484 /*
 485  * free device
 486  */
 487 static void snd_virmidi_free(snd_rawmidi_t *rmidi)
 488 {
 489         snd_virmidi_dev_t *rdev = rmidi->private_data;
 490         kfree(rdev);
 491 }
 492
 493 /*
 494  * create a new device
 495  *
 496  */
 497 /* exported */
 498 int snd_virmidi_new(snd_card_t *card, int device, snd_rawmidi_t **rrmidi)
 499 {
 500         snd_rawmidi_t *rmidi;
 501         snd_virmidi_dev_t *rdev;
 502         int err;
 503
 504         *rrmidi = NULL;
 505         if ((err = snd_rawmidi_new(card, "VirMidi", device,
 506                                    16,  /* may be configurable */
 507                                    16,  /* may be configurable */
 508                                    &rmidi)) < 0)
 509                 return err;
 510         strcpy(rmidi->name, rmidi->id);
 511         rdev = kcalloc(1, sizeof(*rdev), GFP_KERNEL);
 512         if (rdev == NULL) {
 513                 snd_device_free(card, rmidi);
 514                 return -ENOMEM;
 515         }
 516         rdev->card = card;
 517         rdev->rmidi = rmidi;
 518         rdev->device = device;
 519         rdev->client = -1;
 520         rwlock_init(&rdev->filelist_lock);
 521         INIT_LIST_HEAD(&rdev->filelist);
 522         rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
 523         rmidi->private_data = rdev;
 524         rmidi->private_free = snd_virmidi_free;
 525         rmidi->ops = &snd_virmidi_global_ops;
 526         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_virmidi_input_ops);
 527         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_virmidi_output_ops);
 528         rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
 529                             SNDRV_RAWMIDI_INFO_OUTPUT |
 530                             SNDRV_RAWMIDI_INFO_DUPLEX;
 531         *rrmidi = rmidi;
 532         return 0;
 533 }
 534
 535 /*
 536  *  ENTRY functions
 537  */
 538
 539 static int __init alsa_virmidi_init(void)
 540 {
 541         return 0;
 542 }
 543
 544 static void __exit alsa_virmidi_exit(void)
 545 {
 546 }
 547
 548 module_init(alsa_virmidi_init)
 549 module_exit(alsa_virmidi_exit)
 550
 551 EXPORT_SYMBOL(snd_virmidi_new);