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); 544