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