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_dev *rdev = substream->rmidi->private_data;
 258         struct snd_virmidi *vmidi = substream->runtime->private_data;
 259
 260         write_lock_irq(&rdev->filelist_lock);
 261         list_del(&vmidi->list);
 262         write_unlock_irq(&rdev->filelist_lock);
 263         snd_midi_event_free(vmidi->parser);
 264         substream->runtime->private_data = NULL;
 265         kfree(vmidi);
 266         return 0;
 267 }
 268
 269 /*
 270  * close rawmidi handle for output
 271  */
 272 static int snd_virmidi_output_close(struct snd_rawmidi_substream *substream)
 273 {
 274         struct snd_virmidi *vmidi = substream->runtime->private_data;
 275         snd_midi_event_free(vmidi->parser);
 276         substream->runtime->private_data = NULL;
 277         kfree(vmidi);
 278         return 0;
 279 }
 280
 281 /*
 282  * subscribe callback - allow output to rawmidi device
 283  */
 284 static int snd_virmidi_subscribe(void *private_data,
 285                                  struct snd_seq_port_subscribe *info)
 286 {
 287         struct snd_virmidi_dev *rdev;
 288
 289         rdev = private_data;
 290         if (!try_module_get(rdev->card->module))
 291                 return -EFAULT;
 292         rdev->flags |= SNDRV_VIRMIDI_SUBSCRIBE;
 293         return 0;
 294 }
 295
 296 /*
 297  * unsubscribe callback - disallow output to rawmidi device
 298  */
 299 static int snd_virmidi_unsubscribe(void *private_data,
 300                                    struct snd_seq_port_subscribe *info)
 301 {
 302         struct snd_virmidi_dev *rdev;
 303
 304         rdev = private_data;
 305         rdev->flags &= ~SNDRV_VIRMIDI_SUBSCRIBE;
 306         module_put(rdev->card->module);
 307         return 0;
 308 }
 309
 310
 311 /*
 312  * use callback - allow input to rawmidi device
 313  */
 314 static int snd_virmidi_use(void *private_data,
 315                            struct snd_seq_port_subscribe *info)
 316 {
 317         struct snd_virmidi_dev *rdev;
 318
 319         rdev = private_data;
 320         if (!try_module_get(rdev->card->module))
 321                 return -EFAULT;
 322         rdev->flags |= SNDRV_VIRMIDI_USE;
 323         return 0;
 324 }
 325
 326 /*
 327  * unuse callback - disallow input to rawmidi device
 328  */
 329 static int snd_virmidi_unuse(void *private_data,
 330                              struct snd_seq_port_subscribe *info)
 331 {
 332         struct snd_virmidi_dev *rdev;
 333
 334         rdev = private_data;
 335         rdev->flags &= ~SNDRV_VIRMIDI_USE;
 336         module_put(rdev->card->module);
 337         return 0;
 338 }
 339
 340
 341 /*
 342  *  Register functions
 343  */
 344
 345 static struct snd_rawmidi_ops snd_virmidi_input_ops = {
 346         .open = snd_virmidi_input_open,
 347         .close = snd_virmidi_input_close,
 348         .trigger = snd_virmidi_input_trigger,
 349 };
 350
 351 static struct snd_rawmidi_ops snd_virmidi_output_ops = {
 352         .open = snd_virmidi_output_open,
 353         .close = snd_virmidi_output_close,
 354         .trigger = snd_virmidi_output_trigger,
 355 };
 356
 357 /*
 358  * create a sequencer client and a port
 359  */
 360 static int snd_virmidi_dev_attach_seq(struct snd_virmidi_dev *rdev)
 361 {
 362         int client;
 363         struct snd_seq_port_callback pcallbacks;
 364         struct snd_seq_port_info *pinfo;
 365         int err;
 366
 367         if (rdev->client >= 0)
 368                 return 0;
 369
 370         pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
 371         if (!pinfo) {
 372                 err = -ENOMEM;
 373                 goto __error;
 374         }
 375
 376         client = snd_seq_create_kernel_client(rdev->card, rdev->device,
 377                                               "%s %d-%d", rdev->rmidi->name,
 378                                               rdev->card->number,
 379                                               rdev->device);
 380         if (client < 0) {
 381                 err = client;
 382                 goto __error;
 383         }
 384         rdev->client = client;
 385
 386         /* create a port */
 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                 | SNDRV_SEQ_PORT_TYPE_SOFTWARE
 395                 | SNDRV_SEQ_PORT_TYPE_PORT;
 396         pinfo->midi_channels = 16;
 397         memset(&pcallbacks, 0, sizeof(pcallbacks));
 398         pcallbacks.owner = THIS_MODULE;
 399         pcallbacks.private_data = rdev;
 400         pcallbacks.subscribe = snd_virmidi_subscribe;
 401         pcallbacks.unsubscribe = snd_virmidi_unsubscribe;
 402         pcallbacks.use = snd_virmidi_use;
 403         pcallbacks.unuse = snd_virmidi_unuse;
 404         pcallbacks.event_input = snd_virmidi_event_input;
 405         pinfo->kernel = &pcallbacks;
 406         err = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, pinfo);
 407         if (err < 0) {
 408                 snd_seq_delete_kernel_client(client);
 409                 rdev->client = -1;
 410                 goto __error;
 411         }
 412
 413         rdev->port = pinfo->addr.port;
 414         err = 0; /* success */
 415
 416  __error:
 417         kfree(pinfo);
 418         return err;
 419 }
 420
 421
 422 /*
 423  * release the sequencer client
 424  */
 425 static void snd_virmidi_dev_detach_seq(struct snd_virmidi_dev *rdev)
 426 {
 427         if (rdev->client >= 0) {
 428                 snd_seq_delete_kernel_client(rdev->client);
 429                 rdev->client = -1;
 430         }
 431 }
 432
 433 /*
 434  * register the device
 435  */
 436 static int snd_virmidi_dev_register(struct snd_rawmidi *rmidi)
 437 {
 438         struct snd_virmidi_dev *rdev = rmidi->private_data;
 439         int err;
 440
 441         switch (rdev->seq_mode) {
 442         case SNDRV_VIRMIDI_SEQ_DISPATCH:
 443                 err = snd_virmidi_dev_attach_seq(rdev);
 444                 if (err < 0)
 445                         return err;
 446                 break;
 447         case SNDRV_VIRMIDI_SEQ_ATTACH:
 448                 if (rdev->client == 0)
 449                         return -EINVAL;
 450                 /* should check presence of port more strictly.. */
 451                 break;
 452         default:
 453                 pr_err("ALSA: seq_virmidi: seq_mode is not set: %d\n", rdev->seq_mode);
 454                 return -EINVAL;
 455         }
 456         return 0;
 457 }
 458
 459
 460 /*
 461  * unregister the device
 462  */
 463 static int snd_virmidi_dev_unregister(struct snd_rawmidi *rmidi)
 464 {
 465         struct snd_virmidi_dev *rdev = rmidi->private_data;
 466
 467         if (rdev->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH)
 468                 snd_virmidi_dev_detach_seq(rdev);
 469         return 0;
 470 }
 471
 472 /*
 473  *
 474  */
 475 static const struct snd_rawmidi_global_ops snd_virmidi_global_ops = {
 476         .dev_register = snd_virmidi_dev_register,
 477         .dev_unregister = snd_virmidi_dev_unregister,
 478 };
 479
 480 /*
 481  * free device
 482  */
 483 static void snd_virmidi_free(struct snd_rawmidi *rmidi)
 484 {
 485         struct snd_virmidi_dev *rdev = rmidi->private_data;
 486         kfree(rdev);
 487 }
 488
 489 /*
 490  * create a new device
 491  *
 492  */
 493 /* exported */
 494 int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi)
 495 {
 496         struct snd_rawmidi *rmidi;
 497         struct snd_virmidi_dev *rdev;
 498         int err;
 499
 500         *rrmidi = NULL;
 501         if ((err = snd_rawmidi_new(card, "VirMidi", device,
 502                                    16,  /* may be configurable */
 503                                    16,  /* may be configurable */
 504                                    &rmidi)) < 0)
 505                 return err;
 506         strcpy(rmidi->name, rmidi->id);
 507         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
 508         if (rdev == NULL) {
 509                 snd_device_free(card, rmidi);
 510                 return -ENOMEM;
 511         }
 512         rdev->card = card;
 513         rdev->rmidi = rmidi;
 514         rdev->device = device;
 515         rdev->client = -1;
 516         rwlock_init(&rdev->filelist_lock);
 517         INIT_LIST_HEAD(&rdev->filelist);
 518         rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
 519         rmidi->private_data = rdev;
 520         rmidi->private_free = snd_virmidi_free;
 521         rmidi->ops = &snd_virmidi_global_ops;
 522         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_virmidi_input_ops);
 523         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_virmidi_output_ops);
 524         rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
 525                             SNDRV_RAWMIDI_INFO_OUTPUT |
 526                             SNDRV_RAWMIDI_INFO_DUPLEX;
 527         *rrmidi = rmidi;
 528         return 0;
 529 }
 530
 531 /*
 532  *  ENTRY functions
 533  */
 534
 535 static int __init alsa_virmidi_init(void)
 536 {
 537         return 0;
 538 }
 539
 540 static void __exit alsa_virmidi_exit(void)
 541 {
 542 }
 543
 544 module_init(alsa_virmidi_init)
 545 module_exit(alsa_virmidi_exit)
 546
 547 EXPORT_SYMBOL(snd_virmidi_new);