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@suse.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 <sound/driver.h>
  30 #include <linux/init.h>
  31 #include <linux/slab.h>
  32 #include <linux/errno.h>
  33 #include <linux/string.h>
  34 #include <linux/moduleparam.h>
  35 #include <asm/semaphore.h>
  36 #include <sound/core.h>
  37 #include <sound/rawmidi.h>
  38 #include <sound/seq_kernel.h>
  39 #include <sound/seq_device.h>
  40 #include <sound/seq_midi_event.h>
  41 #include <sound/initval.h>
  42
  43 MODULE_AUTHOR("Frank van de Pol <fvdpol@coil.demon.nl>, Jaroslav Kysela <perex@suse.cz>");
  44 MODULE_DESCRIPTION("Advanced Linux Sound Architecture sequencer MIDI synth.");
  45 MODULE_LICENSE("GPL");
  46 static int output_buffer_size = PAGE_SIZE;
  47 module_param(output_buffer_size, int, 0644);
  48 MODULE_PARM_DESC(output_buffer_size, "Output buffer size in bytes.");
  49 static int input_buffer_size = PAGE_SIZE;
  50 module_param(input_buffer_size, int, 0644);
  51 MODULE_PARM_DESC(input_buffer_size, "Input buffer size in bytes.");
  52
  53 /* data for this midi synth driver */
  54 struct seq_midisynth {
  55         struct snd_card *card;
  56         int device;
  57         int subdevice;
  58         struct snd_rawmidi_file input_rfile;
  59         struct snd_rawmidi_file output_rfile;
  60         int seq_client;
  61         int seq_port;
  62         struct snd_midi_event *parser;
  63 };
  64
  65 struct seq_midisynth_client {
  66         int seq_client;
  67         int num_ports;
  68         int ports_per_device[SNDRV_RAWMIDI_DEVICES];
  69         struct seq_midisynth *ports[SNDRV_RAWMIDI_DEVICES];
  70 };
  71
  72 static struct seq_midisynth_client *synths[SNDRV_CARDS];
  73 static DECLARE_MUTEX(register_mutex);
  74
  75 /* handle rawmidi input event (MIDI v1.0 stream) */
  76 static void snd_midi_input_event(struct snd_rawmidi_substream *substream)
  77 {
  78         struct snd_rawmidi_runtime *runtime;
  79         struct seq_midisynth *msynth;
  80         struct snd_seq_event ev;
  81         char buf[16], *pbuf;
  82         long res, count;
  83
  84         if (substream == NULL)
  85                 return;
  86         runtime = substream->runtime;
  87         msynth = runtime->private_data;
  88         if (msynth == NULL)
  89                 return;
  90         memset(&ev, 0, sizeof(ev));
  91         while (runtime->avail > 0) {
  92                 res = snd_rawmidi_kernel_read(substream, buf, sizeof(buf));
  93                 if (res <= 0)
  94                         continue;
  95                 if (msynth->parser == NULL)
  96                         continue;
  97                 pbuf = buf;
  98                 while (res > 0) {
  99                         count = snd_midi_event_encode(msynth->parser, pbuf, res, &ev);
 100                         if (count < 0)
 101                                 break;
 102                         pbuf += count;
 103                         res -= count;
 104                         if (ev.type != SNDRV_SEQ_EVENT_NONE) {
 105                                 ev.source.port = msynth->seq_port;
 106                                 ev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
 107                                 snd_seq_kernel_client_dispatch(msynth->seq_client, &ev, 1, 0);
 108                                 /* clear event and reset header */
 109                                 memset(&ev, 0, sizeof(ev));
 110                         }
 111                 }
 112         }
 113 }
 114
 115 static int dump_midi(struct snd_rawmidi_substream *substream, const char *buf, int count)
 116 {
 117         struct snd_rawmidi_runtime *runtime;
 118         int tmp;
 119
 120         snd_assert(substream != NULL || buf != NULL, return -EINVAL);
 121         runtime = substream->runtime;
 122         if ((tmp = runtime->avail) < count) {
 123                 snd_printd("warning, output event was lost (count = %i, available = %i)\n", count, tmp);
 124                 return -ENOMEM;
 125         }
 126         if (snd_rawmidi_kernel_write(substream, buf, count) < count)
 127                 return -EINVAL;
 128         return 0;
 129 }
 130
 131 static int event_process_midi(struct snd_seq_event *ev, int direct,
 132                               void *private_data, int atomic, int hop)
 133 {
 134         struct seq_midisynth *msynth = private_data;
 135         unsigned char msg[10];  /* buffer for constructing midi messages */
 136         struct snd_rawmidi_substream *substream;
 137         int len;
 138
 139         snd_assert(msynth != NULL, return -EINVAL);
 140         substream = msynth->output_rfile.output;
 141         if (substream == NULL)
 142                 return -ENODEV;
 143         if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {        /* special case, to save space */
 144                 if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE) {
 145                         /* invalid event */
 146                         snd_printd("seq_midi: invalid sysex event flags = 0x%x\n", ev->flags);
 147                         return 0;
 148                 }
 149                 snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)dump_midi, substream);
 150                 snd_midi_event_reset_decode(msynth->parser);
 151         } else {
 152                 if (msynth->parser == NULL)
 153                         return -EIO;
 154                 len = snd_midi_event_decode(msynth->parser, msg, sizeof(msg), ev);
 155                 if (len < 0)
 156                         return 0;
 157                 if (dump_midi(substream, msg, len) < 0)
 158                         snd_midi_event_reset_decode(msynth->parser);
 159         }
 160         return 0;
 161 }
 162
 163
 164 static int snd_seq_midisynth_new(struct seq_midisynth *msynth,
 165                                  struct snd_card *card,
 166                                  int device,
 167                                  int subdevice)
 168 {
 169         if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &msynth->parser) < 0)
 170                 return -ENOMEM;
 171         msynth->card = card;
 172         msynth->device = device;
 173         msynth->subdevice = subdevice;
 174         return 0;
 175 }
 176
 177 /* open associated midi device for input */
 178 static int midisynth_subscribe(void *private_data, struct snd_seq_port_subscribe *info)
 179 {
 180         int err;
 181         struct seq_midisynth *msynth = private_data;
 182         struct snd_rawmidi_runtime *runtime;
 183         struct snd_rawmidi_params params;
 184
 185         /* open midi port */
 186         if ((err = snd_rawmidi_kernel_open(msynth->card, msynth->device,
 187                                            msynth->subdevice,
 188                                            SNDRV_RAWMIDI_LFLG_INPUT,
 189                                            &msynth->input_rfile)) < 0) {
 190                 snd_printd("midi input open failed!!!\n");
 191                 return err;
 192         }
 193         runtime = msynth->input_rfile.input->runtime;
 194         memset(&params, 0, sizeof(params));
 195         params.avail_min = 1;
 196         params.buffer_size = input_buffer_size;
 197         if ((err = snd_rawmidi_input_params(msynth->input_rfile.input, &params)) < 0) {
 198                 snd_rawmidi_kernel_release(&msynth->input_rfile);
 199                 return err;
 200         }
 201         snd_midi_event_reset_encode(msynth->parser);
 202         runtime->event = snd_midi_input_event;
 203         runtime->private_data = msynth;
 204         snd_rawmidi_kernel_read(msynth->input_rfile.input, NULL, 0);
 205         return 0;
 206 }
 207
 208 /* close associated midi device for input */
 209 static int midisynth_unsubscribe(void *private_data, struct snd_seq_port_subscribe *info)
 210 {
 211         int err;
 212         struct seq_midisynth *msynth = private_data;
 213
 214         snd_assert(msynth->input_rfile.input != NULL, return -EINVAL);
 215         err = snd_rawmidi_kernel_release(&msynth->input_rfile);
 216         return err;
 217 }
 218
 219 /* open associated midi device for output */
 220 static int midisynth_use(void *private_data, struct snd_seq_port_subscribe *info)
 221 {
 222         int err;
 223         struct seq_midisynth *msynth = private_data;
 224         struct snd_rawmidi_params params;
 225
 226         /* open midi port */
 227         if ((err = snd_rawmidi_kernel_open(msynth->card, msynth->device,
 228                                            msynth->subdevice,
 229                                            SNDRV_RAWMIDI_LFLG_OUTPUT,
 230                                            &msynth->output_rfile)) < 0) {
 231                 snd_printd("midi output open failed!!!\n");
 232                 return err;
 233         }
 234         memset(&params, 0, sizeof(params));
 235         params.avail_min = 1;
 236         params.buffer_size = output_buffer_size;
 237         if ((err = snd_rawmidi_output_params(msynth->output_rfile.output, &params)) < 0) {
 238                 snd_rawmidi_kernel_release(&msynth->output_rfile);
 239                 return err;
 240         }
 241         snd_midi_event_reset_decode(msynth->parser);
 242         return 0;
 243 }
 244
 245 /* close associated midi device for output */
 246 static int midisynth_unuse(void *private_data, struct snd_seq_port_subscribe *info)
 247 {
 248         struct seq_midisynth *msynth = private_data;
 249         unsigned char buf = 0xff; /* MIDI reset */
 250
 251         snd_assert(msynth->output_rfile.output != NULL, return -EINVAL);
 252         /* sending single MIDI reset message to shut the device up */
 253         snd_rawmidi_kernel_write(msynth->output_rfile.output, &buf, 1);
 254         snd_rawmidi_drain_output(msynth->output_rfile.output);
 255         return snd_rawmidi_kernel_release(&msynth->output_rfile);
 256 }
 257
 258 /* delete given midi synth port */
 259 static void snd_seq_midisynth_delete(struct seq_midisynth *msynth)
 260 {
 261         if (msynth == NULL)
 262                 return;
 263
 264         if (msynth->seq_client > 0) {
 265                 /* delete port */
 266                 snd_seq_event_port_detach(msynth->seq_client, msynth->seq_port);
 267         }
 268
 269         if (msynth->parser)
 270                 snd_midi_event_free(msynth->parser);
 271 }
 272
 273 /* register new midi synth port */
 274 static int
 275 snd_seq_midisynth_register_port(struct snd_seq_device *dev)
 276 {
 277         struct seq_midisynth_client *client;
 278         struct seq_midisynth *msynth, *ms;
 279         struct snd_seq_port_info *port;
 280         struct snd_rawmidi_info *info;
 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         down(&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                         up(&register_mutex);
 318                         kfree(info);
 319                         return -ENOMEM;
 320                 }
 321                 client->seq_client =
 322                         snd_seq_create_kernel_client(
 323                                 card, 0, "%s", info->name[0] ?
 324                                 (const char *)info->name : "External MIDI");
 325                 if (client->seq_client < 0) {
 326                         kfree(client);
 327                         up(&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                 port->midi_channels = 16;
 381                 memset(&pcallbacks, 0, sizeof(pcallbacks));
 382                 pcallbacks.owner = THIS_MODULE;
 383                 pcallbacks.private_data = ms;
 384                 pcallbacks.subscribe = midisynth_subscribe;
 385                 pcallbacks.unsubscribe = midisynth_unsubscribe;
 386                 pcallbacks.use = midisynth_use;
 387                 pcallbacks.unuse = midisynth_unuse;
 388                 pcallbacks.event_input = event_process_midi;
 389                 port->kernel = &pcallbacks;
 390                 if (snd_seq_kernel_client_ctl(client->seq_client, SNDRV_SEQ_IOCTL_CREATE_PORT, port)<0)
 391                         goto __nomem;
 392                 ms->seq_client = client->seq_client;
 393                 ms->seq_port = port->addr.port;
 394         }
 395         client->ports_per_device[device] = ports;
 396         client->ports[device] = msynth;
 397         client->num_ports++;
 398         if (newclient)
 399                 synths[card->number] = client;
 400         up(&register_mutex);
 401         kfree(info);
 402         kfree(port);
 403         return 0;       /* success */
 404
 405       __nomem:
 406         if (msynth != NULL) {
 407                 for (p = 0; p < ports; p++)
 408                         snd_seq_midisynth_delete(&msynth[p]);
 409                 kfree(msynth);
 410         }
 411         if (newclient) {
 412                 snd_seq_delete_kernel_client(client->seq_client);
 413                 kfree(client);
 414         }
 415         kfree(info);
 416         kfree(port);
 417         up(&register_mutex);
 418         return -ENOMEM;
 419 }
 420
 421 /* release midi synth port */
 422 static int
 423 snd_seq_midisynth_unregister_port(struct snd_seq_device *dev)
 424 {
 425         struct seq_midisynth_client *client;
 426         struct seq_midisynth *msynth;
 427         struct snd_card *card = dev->card;
 428         int device = dev->device, p, ports;
 429
 430         down(&register_mutex);
 431         client = synths[card->number];
 432         if (client == NULL || client->ports[device] == NULL) {
 433                 up(&register_mutex);
 434                 return -ENODEV;
 435         }
 436         ports = client->ports_per_device[device];
 437         client->ports_per_device[device] = 0;
 438         msynth = client->ports[device];
 439         client->ports[device] = NULL;
 440         for (p = 0; p < ports; p++)
 441                 snd_seq_midisynth_delete(&msynth[p]);
 442         kfree(msynth);
 443         client->num_ports--;
 444         if (client->num_ports <= 0) {
 445                 snd_seq_delete_kernel_client(client->seq_client);
 446                 synths[card->number] = NULL;
 447                 kfree(client);
 448         }
 449         up(&register_mutex);
 450         return 0;
 451 }
 452
 453
 454 static int __init alsa_seq_midi_init(void)
 455 {
 456         static struct snd_seq_dev_ops ops = {
 457                 snd_seq_midisynth_register_port,
 458                 snd_seq_midisynth_unregister_port,
 459         };
 460         memset(&synths, 0, sizeof(synths));
 461         snd_seq_autoload_lock();
 462         snd_seq_device_register_driver(SNDRV_SEQ_DEV_ID_MIDISYNTH, &ops, 0);
 463         snd_seq_autoload_unlock();
 464         return 0;
 465 }
 466
 467 static void __exit alsa_seq_midi_exit(void)
 468 {
 469         snd_seq_device_unregister_driver(SNDRV_SEQ_DEV_ID_MIDISYNTH);
 470 }
 471
 472 module_init(alsa_seq_midi_init)
 473 module_exit(alsa_seq_midi_exit)