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         unsigned long flags;
 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                         while (snd_rawmidi_transmit(substream, buf,
 165                                                     sizeof(buf)) > 0) {
 166                                 /* ignored */
 167                         }
 168                         return;
 169                 }
 170                 if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
 171                         if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
 172                                 return;
 173                         vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
 174                 }
 175                 spin_lock_irqsave(&substream->runtime->lock, flags);
 176                 while (1) {
 177                         count = __snd_rawmidi_transmit_peek(substream, buf, sizeof(buf));
 178                         if (count <= 0)
 179                                 break;
 180                         pbuf = buf;
 181                         while (count > 0) {
 182                                 res = snd_midi_event_encode(vmidi->parser, pbuf, count, &vmidi->event);
 183                                 if (res < 0) {
 184                                         snd_midi_event_reset_encode(vmidi->parser);
 185                                         continue;
 186                                 }
 187                                 __snd_rawmidi_transmit_ack(substream, res);
 188                                 pbuf += res;
 189                                 count -= res;
 190                                 if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
 191                                         if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
 192                                                 goto out;
 193                                         vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
 194                                 }
 195                         }
 196                 }
 197         out:
 198                 spin_unlock_irqrestore(&substream->runtime->lock, flags);
 199         } else {
 200                 vmidi->trigger = 0;
 201         }
 202 }
 203
 204 /*
 205  * open rawmidi handle for input
 206  */
 207 static int snd_virmidi_input_open(struct snd_rawmidi_substream *substream)
 208 {
 209         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 210         struct snd_rawmidi_runtime *runtime = substream->runtime;
 211         struct snd_virmidi *vmidi;
 212         unsigned long flags;
 213
 214         vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
 215         if (vmidi == NULL)
 216                 return -ENOMEM;
 217         vmidi->substream = substream;
 218         if (snd_midi_event_new(0, &vmidi->parser) < 0) {
 219                 kfree(vmidi);
 220                 return -ENOMEM;
 221         }
 222         vmidi->seq_mode = rdev->seq_mode;
 223         vmidi->client = rdev->client;
 224         vmidi->port = rdev->port;
 225         runtime->private_data = vmidi;
 226         write_lock_irqsave(&rdev->filelist_lock, flags);
 227         list_add_tail(&vmidi->list, &rdev->filelist);
 228         write_unlock_irqrestore(&rdev->filelist_lock, flags);
 229         vmidi->rdev = rdev;
 230         return 0;
 231 }
 232
 233 /*
 234  * open rawmidi handle for output
 235  */
 236 static int snd_virmidi_output_open(struct snd_rawmidi_substream *substream)
 237 {
 238         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 239         struct snd_rawmidi_runtime *runtime = substream->runtime;
 240         struct snd_virmidi *vmidi;
 241
 242         vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
 243         if (vmidi == NULL)
 244                 return -ENOMEM;
 245         vmidi->substream = substream;
 246         if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &vmidi->parser) < 0) {
 247                 kfree(vmidi);
 248                 return -ENOMEM;
 249         }
 250         vmidi->seq_mode = rdev->seq_mode;
 251         vmidi->client = rdev->client;
 252         vmidi->port = rdev->port;
 253         snd_virmidi_init_event(vmidi, &vmidi->event);
 254         vmidi->rdev = rdev;
 255         runtime->private_data = vmidi;
 256         return 0;
 257 }
 258
 259 /*
 260  * close rawmidi handle for input
 261  */
 262 static int snd_virmidi_input_close(struct snd_rawmidi_substream *substream)
 263 {
 264         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 265         struct snd_virmidi *vmidi = substream->runtime->private_data;
 266
 267         write_lock_irq(&rdev->filelist_lock);
 268         list_del(&vmidi->list);
 269         write_unlock_irq(&rdev->filelist_lock);
 270         snd_midi_event_free(vmidi->parser);
 271         substream->runtime->private_data = NULL;
 272         kfree(vmidi);
 273         return 0;
 274 }
 275
 276 /*
 277  * close rawmidi handle for output
 278  */
 279 static int snd_virmidi_output_close(struct snd_rawmidi_substream *substream)
 280 {
 281         struct snd_virmidi *vmidi = substream->runtime->private_data;
 282         snd_midi_event_free(vmidi->parser);
 283         substream->runtime->private_data = NULL;
 284         kfree(vmidi);
 285         return 0;
 286 }
 287
 288 /*
 289  * subscribe callback - allow output to rawmidi device
 290  */
 291 static int snd_virmidi_subscribe(void *private_data,
 292                                  struct snd_seq_port_subscribe *info)
 293 {
 294         struct snd_virmidi_dev *rdev;
 295
 296         rdev = private_data;
 297         if (!try_module_get(rdev->card->module))
 298                 return -EFAULT;
 299         rdev->flags |= SNDRV_VIRMIDI_SUBSCRIBE;
 300         return 0;
 301 }
 302
 303 /*
 304  * unsubscribe callback - disallow output to rawmidi device
 305  */
 306 static int snd_virmidi_unsubscribe(void *private_data,
 307                                    struct snd_seq_port_subscribe *info)
 308 {
 309         struct snd_virmidi_dev *rdev;
 310
 311         rdev = private_data;
 312         rdev->flags &= ~SNDRV_VIRMIDI_SUBSCRIBE;
 313         module_put(rdev->card->module);
 314         return 0;
 315 }
 316
 317
 318 /*
 319  * use callback - allow input to rawmidi device
 320  */
 321 static int snd_virmidi_use(void *private_data,
 322                            struct snd_seq_port_subscribe *info)
 323 {
 324         struct snd_virmidi_dev *rdev;
 325
 326         rdev = private_data;
 327         if (!try_module_get(rdev->card->module))
 328                 return -EFAULT;
 329         rdev->flags |= SNDRV_VIRMIDI_USE;
 330         return 0;
 331 }
 332
 333 /*
 334  * unuse callback - disallow input to rawmidi device
 335  */
 336 static int snd_virmidi_unuse(void *private_data,
 337                              struct snd_seq_port_subscribe *info)
 338 {
 339         struct snd_virmidi_dev *rdev;
 340
 341         rdev = private_data;
 342         rdev->flags &= ~SNDRV_VIRMIDI_USE;
 343         module_put(rdev->card->module);
 344         return 0;
 345 }
 346
 347
 348 /*
 349  *  Register functions
 350  */
 351
 352 static const struct snd_rawmidi_ops snd_virmidi_input_ops = {
 353         .open = snd_virmidi_input_open,
 354         .close = snd_virmidi_input_close,
 355         .trigger = snd_virmidi_input_trigger,
 356 };
 357
 358 static const struct snd_rawmidi_ops snd_virmidi_output_ops = {
 359         .open = snd_virmidi_output_open,
 360         .close = snd_virmidi_output_close,
 361         .trigger = snd_virmidi_output_trigger,
 362 };
 363
 364 /*
 365  * create a sequencer client and a port
 366  */
 367 static int snd_virmidi_dev_attach_seq(struct snd_virmidi_dev *rdev)
 368 {
 369         int client;
 370         struct snd_seq_port_callback pcallbacks;
 371         struct snd_seq_port_info *pinfo;
 372         int err;
 373
 374         if (rdev->client >= 0)
 375                 return 0;
 376
 377         pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
 378         if (!pinfo) {
 379                 err = -ENOMEM;
 380                 goto __error;
 381         }
 382
 383         client = snd_seq_create_kernel_client(rdev->card, rdev->device,
 384                                               "%s %d-%d", rdev->rmidi->name,
 385                                               rdev->card->number,
 386                                               rdev->device);
 387         if (client < 0) {
 388                 err = client;
 389                 goto __error;
 390         }
 391         rdev->client = client;
 392
 393         /* create a port */
 394         pinfo->addr.client = client;
 395         sprintf(pinfo->name, "VirMIDI %d-%d", rdev->card->number, rdev->device);
 396         /* set all capabilities */
 397         pinfo->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
 398         pinfo->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
 399         pinfo->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
 400         pinfo->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
 401                 | SNDRV_SEQ_PORT_TYPE_SOFTWARE
 402                 | SNDRV_SEQ_PORT_TYPE_PORT;
 403         pinfo->midi_channels = 16;
 404         memset(&pcallbacks, 0, sizeof(pcallbacks));
 405         pcallbacks.owner = THIS_MODULE;
 406         pcallbacks.private_data = rdev;
 407         pcallbacks.subscribe = snd_virmidi_subscribe;
 408         pcallbacks.unsubscribe = snd_virmidi_unsubscribe;
 409         pcallbacks.use = snd_virmidi_use;
 410         pcallbacks.unuse = snd_virmidi_unuse;
 411         pcallbacks.event_input = snd_virmidi_event_input;
 412         pinfo->kernel = &pcallbacks;
 413         err = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, pinfo);
 414         if (err < 0) {
 415                 snd_seq_delete_kernel_client(client);
 416                 rdev->client = -1;
 417                 goto __error;
 418         }
 419
 420         rdev->port = pinfo->addr.port;
 421         err = 0; /* success */
 422
 423  __error:
 424         kfree(pinfo);
 425         return err;
 426 }
 427
 428
 429 /*
 430  * release the sequencer client
 431  */
 432 static void snd_virmidi_dev_detach_seq(struct snd_virmidi_dev *rdev)
 433 {
 434         if (rdev->client >= 0) {
 435                 snd_seq_delete_kernel_client(rdev->client);
 436                 rdev->client = -1;
 437         }
 438 }
 439
 440 /*
 441  * register the device
 442  */
 443 static int snd_virmidi_dev_register(struct snd_rawmidi *rmidi)
 444 {
 445         struct snd_virmidi_dev *rdev = rmidi->private_data;
 446         int err;
 447
 448         switch (rdev->seq_mode) {
 449         case SNDRV_VIRMIDI_SEQ_DISPATCH:
 450                 err = snd_virmidi_dev_attach_seq(rdev);
 451                 if (err < 0)
 452                         return err;
 453                 break;
 454         case SNDRV_VIRMIDI_SEQ_ATTACH:
 455                 if (rdev->client == 0)
 456                         return -EINVAL;
 457                 /* should check presence of port more strictly.. */
 458                 break;
 459         default:
 460                 pr_err("ALSA: seq_virmidi: seq_mode is not set: %d\n", rdev->seq_mode);
 461                 return -EINVAL;
 462         }
 463         return 0;
 464 }
 465
 466
 467 /*
 468  * unregister the device
 469  */
 470 static int snd_virmidi_dev_unregister(struct snd_rawmidi *rmidi)
 471 {
 472         struct snd_virmidi_dev *rdev = rmidi->private_data;
 473
 474         if (rdev->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH)
 475                 snd_virmidi_dev_detach_seq(rdev);
 476         return 0;
 477 }
 478
 479 /*
 480  *
 481  */
 482 static const struct snd_rawmidi_global_ops snd_virmidi_global_ops = {
 483         .dev_register = snd_virmidi_dev_register,
 484         .dev_unregister = snd_virmidi_dev_unregister,
 485 };
 486
 487 /*
 488  * free device
 489  */
 490 static void snd_virmidi_free(struct snd_rawmidi *rmidi)
 491 {
 492         struct snd_virmidi_dev *rdev = rmidi->private_data;
 493         kfree(rdev);
 494 }
 495
 496 /*
 497  * create a new device
 498  *
 499  */
 500 /* exported */
 501 int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi)
 502 {
 503         struct snd_rawmidi *rmidi;
 504         struct snd_virmidi_dev *rdev;
 505         int err;
 506
 507         *rrmidi = NULL;
 508         if ((err = snd_rawmidi_new(card, "VirMidi", device,
 509                                    16,  /* may be configurable */
 510                                    16,  /* may be configurable */
 511                                    &rmidi)) < 0)
 512                 return err;
 513         strcpy(rmidi->name, rmidi->id);
 514         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
 515         if (rdev == NULL) {
 516                 snd_device_free(card, rmidi);
 517                 return -ENOMEM;
 518         }
 519         rdev->card = card;
 520         rdev->rmidi = rmidi;
 521         rdev->device = device;
 522         rdev->client = -1;
 523         rwlock_init(&rdev->filelist_lock);
 524         INIT_LIST_HEAD(&rdev->filelist);
 525         rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
 526         rmidi->private_data = rdev;
 527         rmidi->private_free = snd_virmidi_free;
 528         rmidi->ops = &snd_virmidi_global_ops;
 529         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_virmidi_input_ops);
 530         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_virmidi_output_ops);
 531         rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
 532                             SNDRV_RAWMIDI_INFO_OUTPUT |
 533                             SNDRV_RAWMIDI_INFO_DUPLEX;
 534         *rrmidi = rmidi;
 535         return 0;
 536 }
 537 EXPORT_SYMBOL(snd_virmidi_new);
 538
 539 /*
 540  *  ENTRY functions
 541  */
 542
 543 static int __init alsa_virmidi_init(void)
 544 {
 545         return 0;
 546 }
 547
 548 static void __exit alsa_virmidi_exit(void)
 549 {
 550 }
 551
 552 module_init(alsa_virmidi_init)
 553 module_exit(alsa_virmidi_exit)