sound/core/seq/seq_midi.c

   1 /*
   2  *   Generic MIDI synth driver for ALSA sequencer
   3  *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
   4  *                         Jaroslav Kysela <perex@perex.cz>
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 /*
  23 Possible options for midisynth module:
  24         - automatic opening of midi ports on first received event or subscription
  25           (close will be performed when client leaves)
  26 */
  27
  28
  29 #include <linux/init.h>
  30 #include <linux/slab.h>
  31 #include <linux/errno.h>
  32 #include <linux/string.h>
  33 #include <linux/moduleparam.h>
  34 #include <linux/mutex.h>
  35 #include <sound/core.h>
  36 #include <sound/rawmidi.h>
  37 #include <sound/seq_kernel.h>
  38 #include <sound/seq_device.h>
  39 #include <sound/seq_midi_event.h>
  40 #include <sound/initval.h>
  41
  42 MODULE_AUTHOR("Frank van de Pol <fvdpol@coil.demon.nl>, Jaroslav Kysela <perex@perex.cz>");
  43 MODULE_DESCRIPTION("Advanced Linux Sound Architecture sequencer MIDI synth.");
  44 MODULE_LICENSE("GPL");
  45 static int output_buffer_size = PAGE_SIZE;
  46 module_param(output_buffer_size, int, 0644);
  47 MODULE_PARM_DESC(output_buffer_size, "Output buffer size in bytes.");
  48 static int input_buffer_size = PAGE_SIZE;
  49 module_param(input_buffer_size, int, 0644);
  50 MODULE_PARM_DESC(input_buffer_size, "Input buffer size in bytes.");
  51
  52 /* data for this midi synth driver */
  53 struct seq_midisynth {
  54         struct snd_card *card;
  55         int device;
  56         int subdevice;
  57         struct snd_rawmidi_file input_rfile;
  58         struct snd_rawmidi_file output_rfile;
  59         int seq_client;
  60         int seq_port;
  61         struct snd_midi_event *parser;
  62 };
  63
  64 struct seq_midisynth_client {
  65         int seq_client;
  66         int num_ports;
  67         int ports_per_device[SNDRV_RAWMIDI_DEVICES];
  68         struct seq_midisynth *ports[SNDRV_RAWMIDI_DEVICES];
  69 };
  70
  71 static struct seq_midisynth_client *synths[SNDRV_CARDS];
  72 static DEFINE_MUTEX(register_mutex);
  73
  74 /* handle rawmidi input event (MIDI v1.0 stream) */
  75 static void snd_midi_input_event(struct snd_rawmidi_substream *substream)
  76 {
  77         struct snd_rawmidi_runtime *runtime;
  78         struct seq_midisynth *msynth;
  79         struct snd_seq_event ev;
  80         char buf[16], *pbuf;
  81         long res, count;
  82
  83         if (substream == NULL)
  84                 return;
  85         runtime = substream->runtime;
  86         msynth = runtime->private_data;
  87         if (msynth == NULL)
  88                 return;
  89         memset(&ev, 0, sizeof(ev));
  90         while (runtime->avail > 0) {
  91                 res = snd_rawmidi_kernel_read(substream, buf, sizeof(buf));
  92                 if (res <= 0)
  93                         continue;
  94                 if (msynth->parser == NULL)
  95                         continue;
  96                 pbuf = buf;
  97                 while (res > 0) {
  98                         count = snd_midi_event_encode(msynth->parser, pbuf, res, &ev);
  99                         if (count < 0)
 100                                 break;
 101                         pbuf += count;
 102                         res -= count;
 103                         if (ev.type != SNDRV_SEQ_EVENT_NONE) {
 104                                 ev.source.port = msynth->seq_port;
 105                                 ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
 106                                 snd_seq_kernel_client_dispatch(msynth->seq_client, &ev, 1, 0);
 107                                 /* clear event and reset header */
 108                                 memset(&ev, 0, sizeof(ev));
 109                         }
 110                 }
 111         }
 112 }
 113
 114 static int dump_midi(struct snd_rawmidi_substream *substream, const char *buf, int count)
 115 {
 116         struct snd_rawmidi_runtime *runtime;
 117         int tmp;
 118
 119         snd_assert(substream != NULL || buf != NULL, return -EINVAL);
 120         runtime = substream->runtime;
 121         if ((tmp = runtime->avail) < count) {
 122                 snd_printd("warning, output event was lost (count = %i, available = %i)\n", count, tmp);
 123                 return -ENOMEM;
 124         }
 125         if (snd_rawmidi_kernel_write(substream, buf, count) < count)
 126                 return -EINVAL;
 127         return 0;
 128 }
 129
 130 static int event_process_midi(struct snd_seq_event *ev, int direct,
 131                               void *private_data, int atomic, int hop)
 132 {
 133         struct seq_midisynth *msynth = private_data;
 134         unsigned char msg[10];  /* buffer for constructing midi messages */
 135         struct snd_rawmidi_substream *substream;
 136         int len;
 137
 138         snd_assert(msynth != NULL, return -EINVAL);
 139         substream = msynth->output_rfile.output;
 140         if (substream == NULL)
 141                 return -ENODEV;
 142         if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {        /* special case, to save space */
 143                 if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE) {
 144                         /* invalid event */
 145                         snd_printd("seq_midi: invalid sysex event flags = 0x%x\n", ev->flags);
 146                         return 0;
 147                 }
 148                 snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)dump_midi, substream);
 149                 snd_midi_event_reset_decode(msynth->parser);
 150         } else {
 151                 if (msynth->parser == NULL)
 152                         return -EIO;
 153                 len = snd_midi_event_decode(msynth->parser, msg, sizeof(msg), ev);
 154                 if (len < 0)
 155                         return 0;
 156                 if (dump_midi(substream, msg, len) < 0)
 157                         snd_midi_event_reset_decode(msynth->parser);
 158         }
 159         return 0;
 160 }
 161
 162
 163 static int snd_seq_midisynth_new(struct seq_midisynth *msynth,
 164                                  struct snd_card *card,
 165                                  int device,
 166                                  int subdevice)
 167 {
 168         if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &msynth->parser) < 0)
 169                 return -ENOMEM;
 170         msynth->card = card;
 171         msynth->device = device;
 172         msynth->subdevice = subdevice;
 173         return 0;
 174 }
 175
 176 /* open associated midi device for input */
 177 static int midisynth_subscribe(void *private_data, struct snd_seq_port_subscribe *info)
 178 {
 179         int err;
 180         struct seq_midisynth *msynth = private_data;
 181         struct snd_rawmidi_runtime *runtime;
 182         struct snd_rawmidi_params params;
 183
 184         /* open midi port */
 185         if ((err = snd_rawmidi_kernel_open(msynth->card, msynth->device,
 186                                            msynth->subdevice,
 187                                            SNDRV_RAWMIDI_LFLG_INPUT,
 188                                            &msynth->input_rfile)) < 0) {
 189                 snd_printd("midi input open failed!!!\n");
 190                 return err;
 191         }
 192         runtime = msynth->input_rfile.input->runtime;
 193         memset(&params, 0, sizeof(params));
 194         params.avail_min = 1;
 195         params.buffer_size = input_buffer_size;
 196         if ((err = snd_rawmidi_input_params(msynth->input_rfile.input, &params)) < 0) {
 197                 snd_rawmidi_kernel_release(&msynth->input_rfile);
 198                 return err;
 199         }
 200         snd_midi_event_reset_encode(msynth->parser);
 201         runtime->event = snd_midi_input_event;
 202         runtime->private_data = msynth;
 203         snd_rawmidi_kernel_read(msynth->input_rfile.input, NULL, 0);
 204         return 0;
 205 }
 206
 207 /* close associated midi device for input */
 208 static int midisynth_unsubscribe(void *private_data, struct snd_seq_port_subscribe *info)
 209 {
 210         int err;
 211         struct seq_midisynth *msynth = private_data;
 212
 213         snd_assert(msynth->input_rfile.input != NULL, return -EINVAL);
 214         err = snd_rawmidi_kernel_release(&msynth->input_rfile);
 215         return err;
 216 }
 217
 218 /* open associated midi device for output */
 219 static int midisynth_use(void *private_data, struct snd_seq_port_subscribe *info)
 220 {
 221         int err;
 222         struct seq_midisynth *msynth = private_data;
 223         struct snd_rawmidi_params params;
 224
 225         /* open midi port */
 226         if ((err = snd_rawmidi_kernel_open(msynth->card, msynth->device,
 227                                            msynth->subdevice,
 228                                            SNDRV_RAWMIDI_LFLG_OUTPUT,
 229                                            &msynth->output_rfile)) < 0) {
 230                 snd_printd("midi output open failed!!!\n");
 231                 return err;
 232         }
 233         memset(&params, 0, sizeof(params));
 234         params.avail_min = 1;
 235         params.buffer_size = output_buffer_size;
 236         if ((err = snd_rawmidi_output_params(msynth->output_rfile.output, &params)) < 0) {
 237                 snd_rawmidi_kernel_release(&msynth->output_rfile);
 238                 return err;
 239         }
 240         snd_midi_event_reset_decode(msynth->parser);
 241         return 0;
 242 }
 243
 244 /* close associated midi device for output */
 245 static int midisynth_unuse(void *private_data, struct snd_seq_port_subscribe *info)
 246 {
 247         struct seq_midisynth *msynth = private_data;
 248         unsigned char buf = 0xff; /* MIDI reset */
 249
 250         snd_assert(msynth->output_rfile.output != NULL, return -EINVAL);
 251         /* sending single MIDI reset message to shut the device up */
 252         snd_rawmidi_kernel_write(msynth->output_rfile.output, &buf, 1);
 253         snd_rawmidi_drain_output(msynth->output_rfile.output);
 254         return snd_rawmidi_kernel_release(&msynth->output_rfile);
 255 }
 256
 257 /* delete given midi synth port */
 258 static void snd_seq_midisynth_delete(struct seq_midisynth *msynth)
 259 {
 260         if (msynth == NULL)
 261                 return;
 262
 263         if (msynth->seq_client > 0) {
 264                 /* delete port */
 265                 snd_seq_event_port_detach(msynth->seq_client, msynth->seq_port);
 266         }
 267
 268         if (msynth->parser)
 269                 snd_midi_event_free(msynth->parser);
 270 }
 271
 272 /* register new midi synth port */
 273 static int
 274 snd_seq_midisynth_register_port(struct snd_seq_device *dev)
 275 {
 276         struct seq_midisynth_client *client;
 277         struct seq_midisynth *msynth, *ms;
 278         struct snd_seq_port_info *port;
 279         struct snd_rawmidi_info *info;
 280         struct snd_rawmidi *rmidi = dev->private_data;
 281         int newclient = 0;
 282         unsigned int p, ports;
 283         struct snd_seq_port_callback pcallbacks;
 284         struct snd_card *card = dev->card;
 285         int device = dev->device;
 286         unsigned int input_count = 0, output_count = 0;
 287
 288         snd_assert(card != NULL && device >= 0 && device < SNDRV_RAWMIDI_DEVICES, return -EINVAL);
 289         info = kmalloc(sizeof(*info), GFP_KERNEL);
 290         if (! info)
 291                 return -ENOMEM;
 292         info->device = device;
 293         info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
 294         info->subdevice = 0;
 295         if (snd_rawmidi_info_select(card, info) >= 0)
 296                 output_count = info->subdevices_count;
 297         info->stream = SNDRV_RAWMIDI_STREAM_INPUT;
 298         if (snd_rawmidi_info_select(card, info) >= 0) {
 299                 input_count = info->subdevices_count;
 300         }
 301         ports = output_count;
 302         if (ports < input_count)
 303                 ports = input_count;
 304         if (ports == 0) {
 305                 kfree(info);
 306                 return -ENODEV;
 307         }
 308         if (ports > (256 / SNDRV_RAWMIDI_DEVICES))
 309                 ports = 256 / SNDRV_RAWMIDI_DEVICES;
 310
 311         mutex_lock(&register_mutex);
 312         client = synths[card->number];
 313         if (client == NULL) {
 314                 newclient = 1;
 315                 client = kzalloc(sizeof(*client), GFP_KERNEL);
 316                 if (client == NULL) {
 317                         mutex_unlock(&register_mutex);
 318                         kfree(info);
 319                         return -ENOMEM;
 320                 }
 321                 client->seq_client =
 322                         snd_seq_create_kernel_client(
 323                                 card, 0, "%s", card->shortname[0] ?
 324                                 (const char *)card->shortname : "External MIDI");
 325                 if (client->seq_client < 0) {
 326                         kfree(client);
 327                         mutex_unlock(&register_mutex);
 328                         kfree(info);
 329                         return -ENOMEM;
 330                 }
 331         }
 332
 333         msynth = kcalloc(ports, sizeof(struct seq_midisynth), GFP_KERNEL);
 334         port = kmalloc(sizeof(*port), GFP_KERNEL);
 335         if (msynth == NULL || port == NULL)
 336                 goto __nomem;
 337
 338         for (p = 0; p < ports; p++) {
 339                 ms = &msynth[p];
 340
 341                 if (snd_seq_midisynth_new(ms, card, device, p) < 0)
 342                         goto __nomem;
 343
 344                 /* declare port */
 345                 memset(port, 0, sizeof(*port));
 346                 port->addr.client = client->seq_client;
 347                 port->addr.port = device * (256 / SNDRV_RAWMIDI_DEVICES) + p;
 348                 port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
 349                 memset(info, 0, sizeof(*info));
 350                 info->device = device;
 351                 if (p < output_count)
 352                         info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
 353                 else
 354                         info->stream = SNDRV_RAWMIDI_STREAM_INPUT;
 355                 info->subdevice = p;
 356                 if (snd_rawmidi_info_select(card, info) >= 0)
 357                         strcpy(port->name, info->subname);
 358                 if (! port->name[0]) {
 359                         if (info->name[0]) {
 360                                 if (ports > 1)
 361                                         snprintf(port->name, sizeof(port->name), "%s-%d", info->name, p);
 362                                 else
 363                                         snprintf(port->name, sizeof(port->name), "%s", info->name);
 364                         } else {
 365                                 /* last resort */
 366                                 if (ports > 1)
 367                                         sprintf(port->name, "MIDI %d-%d-%d", card->number, device, p);
 368                                 else
 369                                         sprintf(port->name, "MIDI %d-%d", card->number, device);
 370                         }
 371                 }
 372                 if ((info->flags & SNDRV_RAWMIDI_INFO_OUTPUT) && p < output_count)
 373                         port->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
 374                 if ((info->flags & SNDRV_RAWMIDI_INFO_INPUT) && p < input_count)
 375                         port->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
 376                 if ((port->capability & (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ)) == (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ) &&
 377                     info->flags & SNDRV_RAWMIDI_INFO_DUPLEX)
 378                         port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
 379                 port->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
 380                         | SNDRV_SEQ_PORT_TYPE_HARDWARE
 381                         | SNDRV_SEQ_PORT_TYPE_PORT;
 382                 port->midi_channels = 16;
 383                 memset(&pcallbacks, 0, sizeof(pcallbacks));
 384                 pcallbacks.owner = THIS_MODULE;
 385                 pcallbacks.private_data = ms;
 386                 pcallbacks.subscribe = midisynth_subscribe;
 387                 pcallbacks.unsubscribe = midisynth_unsubscribe;
 388                 pcallbacks.use = midisynth_use;
 389                 pcallbacks.unuse = midisynth_unuse;
 390                 pcallbacks.event_input = event_process_midi;
 391                 port->kernel = &pcallbacks;
 392                 if (rmidi->ops && rmidi->ops->get_port_info)
 393                         rmidi->ops->get_port_info(rmidi, p, port);
 394                 if (snd_seq_kernel_client_ctl(client->seq_client, SNDRV_SEQ_IOCTL_CREATE_PORT, port)<0)
 395                         goto __nomem;
 396                 ms->seq_client = client->seq_client;
 397                 ms->seq_port = port->addr.port;
 398         }
 399         client->ports_per_device[device] = ports;
 400         client->ports[device] = msynth;
 401         client->num_ports++;
 402         if (newclient)
 403                 synths[card->number] = client;
 404         mutex_unlock(&register_mutex);
 405         kfree(info);
 406         kfree(port);
 407         return 0;       /* success */
 408
 409       __nomem:
 410         if (msynth != NULL) {
 411                 for (p = 0; p < ports; p++)
 412                         snd_seq_midisynth_delete(&msynth[p]);
 413                 kfree(msynth);
 414         }
 415         if (newclient) {
 416                 snd_seq_delete_kernel_client(client->seq_client);
 417                 kfree(client);
 418         }
 419         kfree(info);
 420         kfree(port);
 421         mutex_unlock(&register_mutex);
 422         return -ENOMEM;
 423 }
 424
 425 /* release midi synth port */
 426 static int
 427 snd_seq_midisynth_unregister_port(struct snd_seq_device *dev)
 428 {
 429         struct seq_midisynth_client *client;
 430         struct seq_midisynth *msynth;
 431         struct snd_card *card = dev->card;
 432         int device = dev->device, p, ports;
 433
 434         mutex_lock(&register_mutex);
 435         client = synths[card->number];
 436         if (client == NULL || client->ports[device] == NULL) {
 437                 mutex_unlock(&register_mutex);
 438                 return -ENODEV;
 439         }
 440         ports = client->ports_per_device[device];
 441         client->ports_per_device[device] = 0;
 442         msynth = client->ports[device];
 443         client->ports[device] = NULL;
 444         for (p = 0; p < ports; p++)
 445                 snd_seq_midisynth_delete(&msynth[p]);
 446         kfree(msynth);
 447         client->num_ports--;
 448         if (client->num_ports <= 0) {
 449                 snd_seq_delete_kernel_client(client->seq_client);
 450                 synths[card->number] = NULL;
 451                 kfree(client);
 452         }
 453         mutex_unlock(&register_mutex);
 454         return 0;
 455 }
 456
 457
 458 static int __init alsa_seq_midi_init(void)
 459 {
 460         static struct snd_seq_dev_ops ops = {
 461                 snd_seq_midisynth_register_port,
 462                 snd_seq_midisynth_unregister_port,
 463         };
 464         memset(&synths, 0, sizeof(synths));
 465         snd_seq_autoload_lock();
 466         snd_seq_device_register_driver(SNDRV_SEQ_DEV_ID_MIDISYNTH, &ops, 0);
 467         snd_seq_autoload_unlock();
 468         return 0;
 469 }
 470
 471 static void __exit alsa_seq_midi_exit(void)
 472 {
 473         snd_seq_device_unregister_driver(SNDRV_SEQ_DEV_ID_MIDISYNTH);
 474 }
 475
 476 module_init(alsa_seq_midi_init)
 477 module_exit(alsa_seq_midi_exit)