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 {
  82         struct snd_virmidi *vmidi;
  83         unsigned char msg[4];
  84         int len;
  85
  86         read_lock(&rdev->filelist_lock);
  87         list_for_each_entry(vmidi, &rdev->filelist, list) {
  88                 if (!vmidi->trigger)
  89                         continue;
  90                 if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {
  91                         if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
  92                                 continue;
  93                         snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)snd_rawmidi_receive, vmidi->substream);
  94                 } else {
  95                         len = snd_midi_event_decode(vmidi->parser, msg, sizeof(msg), ev);
  96                         if (len > 0)
  97                                 snd_rawmidi_receive(vmidi->substream, msg, len);
  98                 }
  99         }
 100         read_unlock(&rdev->filelist_lock);
 101
 102         return 0;
 103 }
 104
 105 /*
 106  * receive an event from the remote virmidi port
 107  *
 108  * for rawmidi inputs, you can call this function from the event
 109  * handler of a remote port which is attached to the virmidi via
 110  * SNDRV_VIRMIDI_SEQ_ATTACH.
 111  */
 112 #if 0
 113 int snd_virmidi_receive(struct snd_rawmidi *rmidi, struct snd_seq_event *ev)
 114 {
 115         struct snd_virmidi_dev *rdev;
 116
 117         rdev = rmidi->private_data;
 118         return snd_virmidi_dev_receive_event(rdev, ev);
 119 }
 120 #endif  /*  0  */
 121
 122 /*
 123  * event handler of virmidi port
 124  */
 125 static int snd_virmidi_event_input(struct snd_seq_event *ev, int direct,
 126                                    void *private_data, int atomic, int hop)
 127 {
 128         struct snd_virmidi_dev *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(struct snd_rawmidi_substream *substream, int up)
 140 {
 141         struct snd_virmidi *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(struct snd_rawmidi_substream *substream, int up)
 154 {
 155         struct snd_virmidi *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, in_atomic(), 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, in_atomic(), 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(struct snd_rawmidi_substream *substream)
 201 {
 202         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 203         struct snd_rawmidi_runtime *runtime = substream->runtime;
 204         struct snd_virmidi *vmidi;
 205         unsigned long flags;
 206
 207         vmidi = kzalloc(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(struct snd_rawmidi_substream *substream)
 230 {
 231         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 232         struct snd_rawmidi_runtime *runtime = substream->runtime;
 233         struct snd_virmidi *vmidi;
 234
 235         vmidi = kzalloc(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(struct snd_rawmidi_substream *substream)
 256 {
 257         struct snd_virmidi *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(struct snd_rawmidi_substream *substream)
 269 {
 270         struct snd_virmidi *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,
 281                                  struct snd_seq_port_subscribe *info)
 282 {
 283         struct snd_virmidi_dev *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,
 296                                    struct snd_seq_port_subscribe *info)
 297 {
 298         struct snd_virmidi_dev *rdev;
 299
 300         rdev = private_data;
 301         rdev->flags &= ~SNDRV_VIRMIDI_SUBSCRIBE;
 302         module_put(rdev->card->module);
 303         return 0;
 304 }
 305
 306
 307 /*
 308  * use callback - allow input to rawmidi device
 309  */
 310 static int snd_virmidi_use(void *private_data,
 311                            struct snd_seq_port_subscribe *info)
 312 {
 313         struct snd_virmidi_dev *rdev;
 314
 315         rdev = private_data;
 316         if (!try_module_get(rdev->card->module))
 317                 return -EFAULT;
 318         rdev->flags |= SNDRV_VIRMIDI_USE;
 319         return 0;
 320 }
 321
 322 /*
 323  * unuse callback - disallow input to rawmidi device
 324  */
 325 static int snd_virmidi_unuse(void *private_data,
 326                              struct snd_seq_port_subscribe *info)
 327 {
 328         struct snd_virmidi_dev *rdev;
 329
 330         rdev = private_data;
 331         rdev->flags &= ~SNDRV_VIRMIDI_USE;
 332         module_put(rdev->card->module);
 333         return 0;
 334 }
 335
 336
 337 /*
 338  *  Register functions
 339  */
 340
 341 static struct snd_rawmidi_ops snd_virmidi_input_ops = {
 342         .open = snd_virmidi_input_open,
 343         .close = snd_virmidi_input_close,
 344         .trigger = snd_virmidi_input_trigger,
 345 };
 346
 347 static struct snd_rawmidi_ops snd_virmidi_output_ops = {
 348         .open = snd_virmidi_output_open,
 349         .close = snd_virmidi_output_close,
 350         .trigger = snd_virmidi_output_trigger,
 351 };
 352
 353 /*
 354  * create a sequencer client and a port
 355  */
 356 static int snd_virmidi_dev_attach_seq(struct snd_virmidi_dev *rdev)
 357 {
 358         int client;
 359         struct snd_seq_port_callback pcallbacks;
 360         struct snd_seq_port_info *pinfo;
 361         int err;
 362
 363         if (rdev->client >= 0)
 364                 return 0;
 365
 366         pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
 367         if (!pinfo) {
 368                 err = -ENOMEM;
 369                 goto __error;
 370         }
 371
 372         client = snd_seq_create_kernel_client(rdev->card, rdev->device,
 373                                               "%s %d-%d", rdev->rmidi->name,
 374                                               rdev->card->number,
 375                                               rdev->device);
 376         if (client < 0) {
 377                 err = client;
 378                 goto __error;
 379         }
 380         rdev->client = client;
 381
 382         /* create a port */
 383         pinfo->addr.client = client;
 384         sprintf(pinfo->name, "VirMIDI %d-%d", rdev->card->number, rdev->device);
 385         /* set all capabilities */
 386         pinfo->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
 387         pinfo->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
 388         pinfo->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
 389         pinfo->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
 390                 | SNDRV_SEQ_PORT_TYPE_SOFTWARE
 391                 | SNDRV_SEQ_PORT_TYPE_PORT;
 392         pinfo->midi_channels = 16;
 393         memset(&pcallbacks, 0, sizeof(pcallbacks));
 394         pcallbacks.owner = THIS_MODULE;
 395         pcallbacks.private_data = rdev;
 396         pcallbacks.subscribe = snd_virmidi_subscribe;
 397         pcallbacks.unsubscribe = snd_virmidi_unsubscribe;
 398         pcallbacks.use = snd_virmidi_use;
 399         pcallbacks.unuse = snd_virmidi_unuse;
 400         pcallbacks.event_input = snd_virmidi_event_input;
 401         pinfo->kernel = &pcallbacks;
 402         err = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, pinfo);
 403         if (err < 0) {
 404                 snd_seq_delete_kernel_client(client);
 405                 rdev->client = -1;
 406                 goto __error;
 407         }
 408
 409         rdev->port = pinfo->addr.port;
 410         err = 0; /* success */
 411
 412  __error:
 413         kfree(pinfo);
 414         return err;
 415 }
 416
 417
 418 /*
 419  * release the sequencer client
 420  */
 421 static void snd_virmidi_dev_detach_seq(struct snd_virmidi_dev *rdev)
 422 {
 423         if (rdev->client >= 0) {
 424                 snd_seq_delete_kernel_client(rdev->client);
 425                 rdev->client = -1;
 426         }
 427 }
 428
 429 /*
 430  * register the device
 431  */
 432 static int snd_virmidi_dev_register(struct snd_rawmidi *rmidi)
 433 {
 434         struct snd_virmidi_dev *rdev = rmidi->private_data;
 435         int err;
 436
 437         switch (rdev->seq_mode) {
 438         case SNDRV_VIRMIDI_SEQ_DISPATCH:
 439                 err = snd_virmidi_dev_attach_seq(rdev);
 440                 if (err < 0)
 441                         return err;
 442                 break;
 443         case SNDRV_VIRMIDI_SEQ_ATTACH:
 444                 if (rdev->client == 0)
 445                         return -EINVAL;
 446                 /* should check presence of port more strictly.. */
 447                 break;
 448         default:
 449                 pr_err("ALSA: seq_virmidi: seq_mode is not set: %d\n", rdev->seq_mode);
 450                 return -EINVAL;
 451         }
 452         return 0;
 453 }
 454
 455
 456 /*
 457  * unregister the device
 458  */
 459 static int snd_virmidi_dev_unregister(struct snd_rawmidi *rmidi)
 460 {
 461         struct snd_virmidi_dev *rdev = rmidi->private_data;
 462
 463         if (rdev->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH)
 464                 snd_virmidi_dev_detach_seq(rdev);
 465         return 0;
 466 }
 467
 468 /*
 469  *
 470  */
 471 static struct snd_rawmidi_global_ops snd_virmidi_global_ops = {
 472         .dev_register = snd_virmidi_dev_register,
 473         .dev_unregister = snd_virmidi_dev_unregister,
 474 };
 475
 476 /*
 477  * free device
 478  */
 479 static void snd_virmidi_free(struct snd_rawmidi *rmidi)
 480 {
 481         struct snd_virmidi_dev *rdev = rmidi->private_data;
 482         kfree(rdev);
 483 }
 484
 485 /*
 486  * create a new device
 487  *
 488  */
 489 /* exported */
 490 int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi)
 491 {
 492         struct snd_rawmidi *rmidi;
 493         struct snd_virmidi_dev *rdev;
 494         int err;
 495
 496         *rrmidi = NULL;
 497         if ((err = snd_rawmidi_new(card, "VirMidi", device,
 498                                    16,  /* may be configurable */
 499                                    16,  /* may be configurable */
 500                                    &rmidi)) < 0)
 501                 return err;
 502         strcpy(rmidi->name, rmidi->id);
 503         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
 504         if (rdev == NULL) {
 505                 snd_device_free(card, rmidi);
 506                 return -ENOMEM;
 507         }
 508         rdev->card = card;
 509         rdev->rmidi = rmidi;
 510         rdev->device = device;
 511         rdev->client = -1;
 512         rwlock_init(&rdev->filelist_lock);
 513         INIT_LIST_HEAD(&rdev->filelist);
 514         rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
 515         rmidi->private_data = rdev;
 516         rmidi->private_free = snd_virmidi_free;
 517         rmidi->ops = &snd_virmidi_global_ops;
 518         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_virmidi_input_ops);
 519         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_virmidi_output_ops);
 520         rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
 521                             SNDRV_RAWMIDI_INFO_OUTPUT |
 522                             SNDRV_RAWMIDI_INFO_DUPLEX;
 523         *rrmidi = rmidi;
 524         return 0;
 525 }
 526
 527 /*
 528  *  ENTRY functions
 529  */
 530
 531 static int __init alsa_virmidi_init(void)
 532 {
 533         return 0;
 534 }
 535
 536 static void __exit alsa_virmidi_exit(void)
 537 {
 538 }
 539
 540 module_init(alsa_virmidi_init)
 541 module_exit(alsa_virmidi_exit)
 542
 543 EXPORT_SYMBOL(snd_virmidi_new);