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/slab.h>
  41 #include <sound/core.h>
  42 #include <sound/rawmidi.h>
  43 #include <sound/info.h>
  44 #include <sound/control.h>
  45 #include <sound/minors.h>
  46 #include <sound/seq_kernel.h>
  47 #include <sound/seq_midi_event.h>
  48 #include <sound/seq_virmidi.h>
  49
  50 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
  51 MODULE_DESCRIPTION("Virtual Raw MIDI client on Sequencer");
  52 MODULE_LICENSE("GPL");
  53
  54 /*
  55  * initialize an event record
  56  */
  57 static void snd_virmidi_init_event(struct snd_virmidi *vmidi,
  58                                    struct snd_seq_event *ev)
  59 {
  60         memset(ev, 0, sizeof(*ev));
  61         ev->source.port = vmidi->port;
  62         switch (vmidi->seq_mode) {
  63         case SNDRV_VIRMIDI_SEQ_DISPATCH:
  64                 ev->dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
  65                 break;
  66         case SNDRV_VIRMIDI_SEQ_ATTACH:
  67                 /* FIXME: source and destination are same - not good.. */
  68                 ev->dest.client = vmidi->client;
  69                 ev->dest.port = vmidi->port;
  70                 break;
  71         }
  72         ev->type = SNDRV_SEQ_EVENT_NONE;
  73 }
  74
  75 /*
  76  * decode input event and put to read buffer of each opened file
  77  */
  78 static int snd_virmidi_dev_receive_event(struct snd_virmidi_dev *rdev,
  79                                          struct snd_seq_event *ev)
  80 {
  81         struct snd_virmidi *vmidi;
  82         unsigned char msg[4];
  83         int len;
  84
  85         read_lock(&rdev->filelist_lock);
  86         list_for_each_entry(vmidi, &rdev->filelist, list) {
  87                 if (!vmidi->trigger)
  88                         continue;
  89                 if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {
  90                         if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
  91                                 continue;
  92                         snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)snd_rawmidi_receive, vmidi->substream);
  93                 } else {
  94                         len = snd_midi_event_decode(vmidi->parser, msg, sizeof(msg), ev);
  95                         if (len > 0)
  96                                 snd_rawmidi_receive(vmidi->substream, msg, len);
  97                 }
  98         }
  99         read_unlock(&rdev->filelist_lock);
 100
 101         return 0;
 102 }
 103
 104 /*
 105  * receive an event from the remote virmidi port
 106  *
 107  * for rawmidi inputs, you can call this function from the event
 108  * handler of a remote port which is attached to the virmidi via
 109  * SNDRV_VIRMIDI_SEQ_ATTACH.
 110  */
 111 #if 0
 112 int snd_virmidi_receive(struct snd_rawmidi *rmidi, struct snd_seq_event *ev)
 113 {
 114         struct snd_virmidi_dev *rdev;
 115
 116         rdev = rmidi->private_data;
 117         return snd_virmidi_dev_receive_event(rdev, ev);
 118 }
 119 #endif  /*  0  */
 120
 121 /*
 122  * event handler of virmidi port
 123  */
 124 static int snd_virmidi_event_input(struct snd_seq_event *ev, int direct,
 125                                    void *private_data, int atomic, int hop)
 126 {
 127         struct snd_virmidi_dev *rdev;
 128
 129         rdev = private_data;
 130         if (!(rdev->flags & SNDRV_VIRMIDI_USE))
 131                 return 0; /* ignored */
 132         return snd_virmidi_dev_receive_event(rdev, ev);
 133 }
 134
 135 /*
 136  * trigger rawmidi stream for input
 137  */
 138 static void snd_virmidi_input_trigger(struct snd_rawmidi_substream *substream, int up)
 139 {
 140         struct snd_virmidi *vmidi = substream->runtime->private_data;
 141
 142         if (up) {
 143                 vmidi->trigger = 1;
 144         } else {
 145                 vmidi->trigger = 0;
 146         }
 147 }
 148
 149 /*
 150  * trigger rawmidi stream for output
 151  */
 152 static void snd_virmidi_output_trigger(struct snd_rawmidi_substream *substream, int up)
 153 {
 154         struct snd_virmidi *vmidi = substream->runtime->private_data;
 155         int count, res;
 156         unsigned char buf[32], *pbuf;
 157
 158         if (up) {
 159                 vmidi->trigger = 1;
 160                 if (vmidi->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH &&
 161                     !(vmidi->rdev->flags & SNDRV_VIRMIDI_SUBSCRIBE)) {
 162                         snd_rawmidi_transmit_ack(substream, substream->runtime->buffer_size - substream->runtime->avail);
 163                         return;         /* ignored */
 164                 }
 165                 if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
 166                         if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
 167                                 return;
 168                         vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
 169                 }
 170                 while (1) {
 171                         count = snd_rawmidi_transmit_peek(substream, buf, sizeof(buf));
 172                         if (count <= 0)
 173                                 break;
 174                         pbuf = buf;
 175                         while (count > 0) {
 176                                 res = snd_midi_event_encode(vmidi->parser, pbuf, count, &vmidi->event);
 177                                 if (res < 0) {
 178                                         snd_midi_event_reset_encode(vmidi->parser);
 179                                         continue;
 180                                 }
 181                                 snd_rawmidi_transmit_ack(substream, res);
 182                                 pbuf += res;
 183                                 count -= res;
 184                                 if (vmidi->event.type != SNDRV_SEQ_EVENT_NONE) {
 185                                         if (snd_seq_kernel_client_dispatch(vmidi->client, &vmidi->event, in_atomic(), 0) < 0)
 186                                                 return;
 187                                         vmidi->event.type = SNDRV_SEQ_EVENT_NONE;
 188                                 }
 189                         }
 190                 }
 191         } else {
 192                 vmidi->trigger = 0;
 193         }
 194 }
 195
 196 /*
 197  * open rawmidi handle for input
 198  */
 199 static int snd_virmidi_input_open(struct snd_rawmidi_substream *substream)
 200 {
 201         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 202         struct snd_rawmidi_runtime *runtime = substream->runtime;
 203         struct snd_virmidi *vmidi;
 204         unsigned long flags;
 205
 206         vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
 207         if (vmidi == NULL)
 208                 return -ENOMEM;
 209         vmidi->substream = substream;
 210         if (snd_midi_event_new(0, &vmidi->parser) < 0) {
 211                 kfree(vmidi);
 212                 return -ENOMEM;
 213         }
 214         vmidi->seq_mode = rdev->seq_mode;
 215         vmidi->client = rdev->client;
 216         vmidi->port = rdev->port;
 217         runtime->private_data = vmidi;
 218         write_lock_irqsave(&rdev->filelist_lock, flags);
 219         list_add_tail(&vmidi->list, &rdev->filelist);
 220         write_unlock_irqrestore(&rdev->filelist_lock, flags);
 221         vmidi->rdev = rdev;
 222         return 0;
 223 }
 224
 225 /*
 226  * open rawmidi handle for output
 227  */
 228 static int snd_virmidi_output_open(struct snd_rawmidi_substream *substream)
 229 {
 230         struct snd_virmidi_dev *rdev = substream->rmidi->private_data;
 231         struct snd_rawmidi_runtime *runtime = substream->runtime;
 232         struct snd_virmidi *vmidi;
 233
 234         vmidi = kzalloc(sizeof(*vmidi), GFP_KERNEL);
 235         if (vmidi == NULL)
 236                 return -ENOMEM;
 237         vmidi->substream = substream;
 238         if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &vmidi->parser) < 0) {
 239                 kfree(vmidi);
 240                 return -ENOMEM;
 241         }
 242         vmidi->seq_mode = rdev->seq_mode;
 243         vmidi->client = rdev->client;
 244         vmidi->port = rdev->port;
 245         snd_virmidi_init_event(vmidi, &vmidi->event);
 246         vmidi->rdev = rdev;
 247         runtime->private_data = vmidi;
 248         return 0;
 249 }
 250
 251 /*
 252  * close rawmidi handle for input
 253  */
 254 static int snd_virmidi_input_close(struct snd_rawmidi_substream *substream)
 255 {
 256         struct snd_virmidi *vmidi = substream->runtime->private_data;
 257         snd_midi_event_free(vmidi->parser);
 258         list_del(&vmidi->list);
 259         substream->runtime->private_data = NULL;
 260         kfree(vmidi);
 261         return 0;
 262 }
 263
 264 /*
 265  * close rawmidi handle for output
 266  */
 267 static int snd_virmidi_output_close(struct snd_rawmidi_substream *substream)
 268 {
 269         struct snd_virmidi *vmidi = substream->runtime->private_data;
 270         snd_midi_event_free(vmidi->parser);
 271         substream->runtime->private_data = NULL;
 272         kfree(vmidi);
 273         return 0;
 274 }
 275
 276 /*
 277  * subscribe callback - allow output to rawmidi device
 278  */
 279 static int snd_virmidi_subscribe(void *private_data,
 280                                  struct snd_seq_port_subscribe *info)
 281 {
 282         struct snd_virmidi_dev *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,
 295                                    struct snd_seq_port_subscribe *info)
 296 {
 297         struct snd_virmidi_dev *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,
 310                            struct snd_seq_port_subscribe *info)
 311 {
 312         struct snd_virmidi_dev *rdev;
 313
 314         rdev = private_data;
 315         if (!try_module_get(rdev->card->module))
 316                 return -EFAULT;
 317         rdev->flags |= SNDRV_VIRMIDI_USE;
 318         return 0;
 319 }
 320
 321 /*
 322  * unuse callback - disallow input to rawmidi device
 323  */
 324 static int snd_virmidi_unuse(void *private_data,
 325                              struct snd_seq_port_subscribe *info)
 326 {
 327         struct snd_virmidi_dev *rdev;
 328
 329         rdev = private_data;
 330         rdev->flags &= ~SNDRV_VIRMIDI_USE;
 331         module_put(rdev->card->module);
 332         return 0;
 333 }
 334
 335
 336 /*
 337  *  Register functions
 338  */
 339
 340 static struct snd_rawmidi_ops snd_virmidi_input_ops = {
 341         .open = snd_virmidi_input_open,
 342         .close = snd_virmidi_input_close,
 343         .trigger = snd_virmidi_input_trigger,
 344 };
 345
 346 static struct snd_rawmidi_ops snd_virmidi_output_ops = {
 347         .open = snd_virmidi_output_open,
 348         .close = snd_virmidi_output_close,
 349         .trigger = snd_virmidi_output_trigger,
 350 };
 351
 352 /*
 353  * create a sequencer client and a port
 354  */
 355 static int snd_virmidi_dev_attach_seq(struct snd_virmidi_dev *rdev)
 356 {
 357         int client;
 358         struct snd_seq_port_callback pcallbacks;
 359         struct snd_seq_port_info *pinfo;
 360         int err;
 361
 362         if (rdev->client >= 0)
 363                 return 0;
 364
 365         pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
 366         if (!pinfo) {
 367                 err = -ENOMEM;
 368                 goto __error;
 369         }
 370
 371         client = snd_seq_create_kernel_client(rdev->card, rdev->device,
 372                                               "%s %d-%d", rdev->rmidi->name,
 373                                               rdev->card->number,
 374                                               rdev->device);
 375         if (client < 0) {
 376                 err = client;
 377                 goto __error;
 378         }
 379         rdev->client = client;
 380
 381         /* create a port */
 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                 | SNDRV_SEQ_PORT_TYPE_SOFTWARE
 390                 | SNDRV_SEQ_PORT_TYPE_PORT;
 391         pinfo->midi_channels = 16;
 392         memset(&pcallbacks, 0, sizeof(pcallbacks));
 393         pcallbacks.owner = THIS_MODULE;
 394         pcallbacks.private_data = rdev;
 395         pcallbacks.subscribe = snd_virmidi_subscribe;
 396         pcallbacks.unsubscribe = snd_virmidi_unsubscribe;
 397         pcallbacks.use = snd_virmidi_use;
 398         pcallbacks.unuse = snd_virmidi_unuse;
 399         pcallbacks.event_input = snd_virmidi_event_input;
 400         pinfo->kernel = &pcallbacks;
 401         err = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_CREATE_PORT, pinfo);
 402         if (err < 0) {
 403                 snd_seq_delete_kernel_client(client);
 404                 rdev->client = -1;
 405                 goto __error;
 406         }
 407
 408         rdev->port = pinfo->addr.port;
 409         err = 0; /* success */
 410
 411  __error:
 412         kfree(pinfo);
 413         return err;
 414 }
 415
 416
 417 /*
 418  * release the sequencer client
 419  */
 420 static void snd_virmidi_dev_detach_seq(struct snd_virmidi_dev *rdev)
 421 {
 422         if (rdev->client >= 0) {
 423                 snd_seq_delete_kernel_client(rdev->client);
 424                 rdev->client = -1;
 425         }
 426 }
 427
 428 /*
 429  * register the device
 430  */
 431 static int snd_virmidi_dev_register(struct snd_rawmidi *rmidi)
 432 {
 433         struct snd_virmidi_dev *rdev = rmidi->private_data;
 434         int err;
 435
 436         switch (rdev->seq_mode) {
 437         case SNDRV_VIRMIDI_SEQ_DISPATCH:
 438                 err = snd_virmidi_dev_attach_seq(rdev);
 439                 if (err < 0)
 440                         return err;
 441                 break;
 442         case SNDRV_VIRMIDI_SEQ_ATTACH:
 443                 if (rdev->client == 0)
 444                         return -EINVAL;
 445                 /* should check presence of port more strictly.. */
 446                 break;
 447         default:
 448                 snd_printk(KERN_ERR "seq_mode is not set: %d\n", rdev->seq_mode);
 449                 return -EINVAL;
 450         }
 451         return 0;
 452 }
 453
 454
 455 /*
 456  * unregister the device
 457  */
 458 static int snd_virmidi_dev_unregister(struct snd_rawmidi *rmidi)
 459 {
 460         struct snd_virmidi_dev *rdev = rmidi->private_data;
 461
 462         if (rdev->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH)
 463                 snd_virmidi_dev_detach_seq(rdev);
 464         return 0;
 465 }
 466
 467 /*
 468  *
 469  */
 470 static struct snd_rawmidi_global_ops snd_virmidi_global_ops = {
 471         .dev_register = snd_virmidi_dev_register,
 472         .dev_unregister = snd_virmidi_dev_unregister,
 473 };
 474
 475 /*
 476  * free device
 477  */
 478 static void snd_virmidi_free(struct snd_rawmidi *rmidi)
 479 {
 480         struct snd_virmidi_dev *rdev = rmidi->private_data;
 481         kfree(rdev);
 482 }
 483
 484 /*
 485  * create a new device
 486  *
 487  */
 488 /* exported */
 489 int snd_virmidi_new(struct snd_card *card, int device, struct snd_rawmidi **rrmidi)
 490 {
 491         struct snd_rawmidi *rmidi;
 492         struct snd_virmidi_dev *rdev;
 493         int err;
 494
 495         *rrmidi = NULL;
 496         if ((err = snd_rawmidi_new(card, "VirMidi", device,
 497                                    16,  /* may be configurable */
 498                                    16,  /* may be configurable */
 499                                    &rmidi)) < 0)
 500                 return err;
 501         strcpy(rmidi->name, rmidi->id);
 502         rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
 503         if (rdev == NULL) {
 504                 snd_device_free(card, rmidi);
 505                 return -ENOMEM;
 506         }
 507         rdev->card = card;
 508         rdev->rmidi = rmidi;
 509         rdev->device = device;
 510         rdev->client = -1;
 511         rwlock_init(&rdev->filelist_lock);
 512         INIT_LIST_HEAD(&rdev->filelist);
 513         rdev->seq_mode = SNDRV_VIRMIDI_SEQ_DISPATCH;
 514         rmidi->private_data = rdev;
 515         rmidi->private_free = snd_virmidi_free;
 516         rmidi->ops = &snd_virmidi_global_ops;
 517         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_virmidi_input_ops);
 518         snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_virmidi_output_ops);
 519         rmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT |
 520                             SNDRV_RAWMIDI_INFO_OUTPUT |
 521                             SNDRV_RAWMIDI_INFO_DUPLEX;
 522         *rrmidi = rmidi;
 523         return 0;
 524 }
 525
 526 /*
 527  *  ENTRY functions
 528  */
 529
 530 static int __init alsa_virmidi_init(void)
 531 {
 532         return 0;
 533 }
 534
 535 static void __exit alsa_virmidi_exit(void)
 536 {
 537 }
 538
 539 module_init(alsa_virmidi_init)
 540 module_exit(alsa_virmidi_exit)
 541
 542 EXPORT_SYMBOL(snd_virmidi_new);