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 typedef struct {
  55         snd_card_t *card;
  56         int device;
  57         int subdevice;
  58         snd_rawmidi_file_t input_rfile;
  59         snd_rawmidi_file_t output_rfile;
  60         int seq_client;
  61         int seq_port;
  62         snd_midi_event_t *parser;
  63 } seq_midisynth_t;
  64
  65 typedef struct {
  66         int seq_client;
  67         int num_ports;
  68         int ports_per_device[SNDRV_RAWMIDI_DEVICES];
  69         seq_midisynth_t *ports[SNDRV_RAWMIDI_DEVICES];
  70 } seq_midisynth_client_t;
  71
  72 static seq_midisynth_client_t *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(snd_rawmidi_substream_t * substream)
  77 {
  78         snd_rawmidi_runtime_t *runtime;
  79         seq_midisynth_t *msynth;
  80         snd_seq_event_t ev;
  81         char buf[16], *pbuf;
  82         long res, count;
  83
  84         if (substream == NULL)
  85                 return;
  86         runtime = substream->runtime;
  87         msynth = (seq_midisynth_t *) 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(snd_rawmidi_substream_t *substream, const char *buf, int count)
 116 {
 117         snd_rawmidi_runtime_t *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(snd_seq_event_t * ev, int direct,
 132                               void *private_data, int atomic, int hop)
 133 {
 134         seq_midisynth_t *msynth = (seq_midisynth_t *) private_data;
 135         unsigned char msg[10];  /* buffer for constructing midi messages */
 136         snd_rawmidi_substream_t *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(seq_midisynth_t *msynth,
 165                                  snd_card_t *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, snd_seq_port_subscribe_t *info)
 179 {
 180         int err;
 181         seq_midisynth_t *msynth = (seq_midisynth_t *)private_data;
 182         snd_rawmidi_runtime_t *runtime;
 183         snd_rawmidi_params_t params;
 184
 185         /* open midi port */
 186         if ((err = snd_rawmidi_kernel_open(msynth->card->number, msynth->device, msynth->subdevice, SNDRV_RAWMIDI_LFLG_INPUT, &msynth->input_rfile)) < 0) {
 187                 snd_printd("midi input open failed!!!\n");
 188                 return err;
 189         }
 190         runtime = msynth->input_rfile.input->runtime;
 191         memset(&params, 0, sizeof(params));
 192         params.avail_min = 1;
 193         params.buffer_size = input_buffer_size;
 194         if ((err = snd_rawmidi_input_params(msynth->input_rfile.input, &params)) < 0) {
 195                 snd_rawmidi_kernel_release(&msynth->input_rfile);
 196                 return err;
 197         }
 198         snd_midi_event_reset_encode(msynth->parser);
 199         runtime->event = snd_midi_input_event;
 200         runtime->private_data = msynth;
 201         snd_rawmidi_kernel_read(msynth->input_rfile.input, NULL, 0);
 202         return 0;
 203 }
 204
 205 /* close associated midi device for input */
 206 static int midisynth_unsubscribe(void *private_data, snd_seq_port_subscribe_t *info)
 207 {
 208         int err;
 209         seq_midisynth_t *msynth = (seq_midisynth_t *)private_data;
 210
 211         snd_assert(msynth->input_rfile.input != NULL, return -EINVAL);
 212         err = snd_rawmidi_kernel_release(&msynth->input_rfile);
 213         return err;
 214 }
 215
 216 /* open associated midi device for output */
 217 static int midisynth_use(void *private_data, snd_seq_port_subscribe_t *info)
 218 {
 219         int err;
 220         seq_midisynth_t *msynth = (seq_midisynth_t *)private_data;
 221         snd_rawmidi_params_t params;
 222
 223         /* open midi port */
 224         if ((err = snd_rawmidi_kernel_open(msynth->card->number, msynth->device, msynth->subdevice, SNDRV_RAWMIDI_LFLG_OUTPUT, &msynth->output_rfile)) < 0) {
 225                 snd_printd("midi output open failed!!!\n");
 226                 return err;
 227         }
 228         memset(&params, 0, sizeof(params));
 229         params.avail_min = 1;
 230         params.buffer_size = output_buffer_size;
 231         if ((err = snd_rawmidi_output_params(msynth->output_rfile.output, &params)) < 0) {
 232                 snd_rawmidi_kernel_release(&msynth->output_rfile);
 233                 return err;
 234         }
 235         snd_midi_event_reset_decode(msynth->parser);
 236         return 0;
 237 }
 238
 239 /* close associated midi device for output */
 240 static int midisynth_unuse(void *private_data, snd_seq_port_subscribe_t *info)
 241 {
 242         seq_midisynth_t *msynth = (seq_midisynth_t *)private_data;
 243         unsigned char buf = 0xff; /* MIDI reset */
 244
 245         snd_assert(msynth->output_rfile.output != NULL, return -EINVAL);
 246         /* sending single MIDI reset message to shut the device up */
 247         snd_rawmidi_kernel_write(msynth->output_rfile.output, &buf, 1);
 248         snd_rawmidi_drain_output(msynth->output_rfile.output);
 249         return snd_rawmidi_kernel_release(&msynth->output_rfile);
 250 }
 251
 252 /* delete given midi synth port */
 253 static void snd_seq_midisynth_delete(seq_midisynth_t *msynth)
 254 {
 255         if (msynth == NULL)
 256                 return;
 257
 258         if (msynth->seq_client > 0) {
 259                 /* delete port */
 260                 snd_seq_event_port_detach(msynth->seq_client, msynth->seq_port);
 261         }
 262
 263         if (msynth->parser)
 264                 snd_midi_event_free(msynth->parser);
 265 }
 266
 267 /* set our client name */
 268 static int set_client_name(seq_midisynth_client_t *client, snd_card_t *card,
 269                            snd_rawmidi_info_t *rmidi)
 270 {
 271         snd_seq_client_info_t cinfo;
 272         const char *name;
 273
 274         memset(&cinfo, 0, sizeof(cinfo));
 275         cinfo.client = client->seq_client;
 276         cinfo.type = KERNEL_CLIENT;
 277         name = rmidi->name[0] ? (const char *)rmidi->name : "External MIDI";
 278         strlcpy(cinfo.name, name, sizeof(cinfo.name));
 279         return snd_seq_kernel_client_ctl(client->seq_client, SNDRV_SEQ_IOCTL_SET_CLIENT_INFO, &cinfo);
 280 }
 281
 282 /* register new midi synth port */
 283 static int
 284 snd_seq_midisynth_register_port(snd_seq_device_t *dev)
 285 {
 286         seq_midisynth_client_t *client;
 287         seq_midisynth_t *msynth, *ms;
 288         snd_seq_port_info_t *port;
 289         snd_rawmidi_info_t *info;
 290         int newclient = 0;
 291         unsigned int p, ports;
 292         snd_seq_client_callback_t callbacks;
 293         snd_seq_port_callback_t pcallbacks;
 294         snd_card_t *card = dev->card;
 295         int device = dev->device;
 296         unsigned int input_count = 0, output_count = 0;
 297
 298         snd_assert(card != NULL && device >= 0 && device < SNDRV_RAWMIDI_DEVICES, return -EINVAL);
 299         info = kmalloc(sizeof(*info), GFP_KERNEL);
 300         if (! info)
 301                 return -ENOMEM;
 302         info->device = device;
 303         info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
 304         info->subdevice = 0;
 305         if (snd_rawmidi_info_select(card, info) >= 0)
 306                 output_count = info->subdevices_count;
 307         info->stream = SNDRV_RAWMIDI_STREAM_INPUT;
 308         if (snd_rawmidi_info_select(card, info) >= 0) {
 309                 input_count = info->subdevices_count;
 310         }
 311         ports = output_count;
 312         if (ports < input_count)
 313                 ports = input_count;
 314         if (ports == 0) {
 315                 kfree(info);
 316                 return -ENODEV;
 317         }
 318         if (ports > (256 / SNDRV_RAWMIDI_DEVICES))
 319                 ports = 256 / SNDRV_RAWMIDI_DEVICES;
 320
 321         down(&register_mutex);
 322         client = synths[card->number];
 323         if (client == NULL) {
 324                 newclient = 1;
 325                 client = kcalloc(1, sizeof(*client), GFP_KERNEL);
 326                 if (client == NULL) {
 327                         up(&register_mutex);
 328                         kfree(info);
 329                         return -ENOMEM;
 330                 }
 331                 memset(&callbacks, 0, sizeof(callbacks));
 332                 callbacks.private_data = client;
 333                 callbacks.allow_input = callbacks.allow_output = 1;
 334                 client->seq_client = snd_seq_create_kernel_client(card, 0, &callbacks);
 335                 if (client->seq_client < 0) {
 336                         kfree(client);
 337                         up(&register_mutex);
 338                         kfree(info);
 339                         return -ENOMEM;
 340                 }
 341                 set_client_name(client, card, info);
 342         } else if (device == 0)
 343                 set_client_name(client, card, info); /* use the first device's name */
 344
 345         msynth = kcalloc(ports, sizeof(seq_midisynth_t), GFP_KERNEL);
 346         port = kmalloc(sizeof(*port), GFP_KERNEL);
 347         if (msynth == NULL || port == NULL)
 348                 goto __nomem;
 349
 350         for (p = 0; p < ports; p++) {
 351                 ms = &msynth[p];
 352
 353                 if (snd_seq_midisynth_new(ms, card, device, p) < 0)
 354                         goto __nomem;
 355
 356                 /* declare port */
 357                 memset(port, 0, sizeof(*port));
 358                 port->addr.client = client->seq_client;
 359                 port->addr.port = device * (256 / SNDRV_RAWMIDI_DEVICES) + p;
 360                 port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
 361                 memset(info, 0, sizeof(*info));
 362                 info->device = device;
 363                 if (p < output_count)
 364                         info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
 365                 else
 366                         info->stream = SNDRV_RAWMIDI_STREAM_INPUT;
 367                 info->subdevice = p;
 368                 if (snd_rawmidi_info_select(card, info) >= 0)
 369                         strcpy(port->name, info->subname);
 370                 if (! port->name[0]) {
 371                         if (info->name[0]) {
 372                                 if (ports > 1)
 373                                         snprintf(port->name, sizeof(port->name), "%s-%d", info->name, p);
 374                                 else
 375                                         snprintf(port->name, sizeof(port->name), "%s", info->name);
 376                         } else {
 377                                 /* last resort */
 378                                 if (ports > 1)
 379                                         sprintf(port->name, "MIDI %d-%d-%d", card->number, device, p);
 380                                 else
 381                                         sprintf(port->name, "MIDI %d-%d", card->number, device);
 382                         }
 383                 }
 384                 if ((info->flags & SNDRV_RAWMIDI_INFO_OUTPUT) && p < output_count)
 385                         port->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
 386                 if ((info->flags & SNDRV_RAWMIDI_INFO_INPUT) && p < input_count)
 387                         port->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
 388                 if ((port->capability & (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ)) == (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ) &&
 389                     info->flags & SNDRV_RAWMIDI_INFO_DUPLEX)
 390                         port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
 391                 port->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC;
 392                 port->midi_channels = 16;
 393                 memset(&pcallbacks, 0, sizeof(pcallbacks));
 394                 pcallbacks.owner = THIS_MODULE;
 395                 pcallbacks.private_data = ms;
 396                 pcallbacks.subscribe = midisynth_subscribe;
 397                 pcallbacks.unsubscribe = midisynth_unsubscribe;
 398                 pcallbacks.use = midisynth_use;
 399                 pcallbacks.unuse = midisynth_unuse;
 400                 pcallbacks.event_input = event_process_midi;
 401                 port->kernel = &pcallbacks;
 402                 if (snd_seq_kernel_client_ctl(client->seq_client, SNDRV_SEQ_IOCTL_CREATE_PORT, port)<0)
 403                         goto __nomem;
 404                 ms->seq_client = client->seq_client;
 405                 ms->seq_port = port->addr.port;
 406         }
 407         client->ports_per_device[device] = ports;
 408         client->ports[device] = msynth;
 409         client->num_ports++;
 410         if (newclient)
 411                 synths[card->number] = client;
 412         up(&register_mutex);
 413         kfree(info);
 414         kfree(port);
 415         return 0;       /* success */
 416
 417       __nomem:
 418         if (msynth != NULL) {
 419                 for (p = 0; p < ports; p++)
 420                         snd_seq_midisynth_delete(&msynth[p]);
 421                 kfree(msynth);
 422         }
 423         if (newclient) {
 424                 snd_seq_delete_kernel_client(client->seq_client);
 425                 kfree(client);
 426         }
 427         kfree(info);
 428         kfree(port);
 429         up(&register_mutex);
 430         return -ENOMEM;
 431 }
 432
 433 /* release midi synth port */
 434 static int
 435 snd_seq_midisynth_unregister_port(snd_seq_device_t *dev)
 436 {
 437         seq_midisynth_client_t *client;
 438         seq_midisynth_t *msynth;
 439         snd_card_t *card = dev->card;
 440         int device = dev->device, p, ports;
 441
 442         down(&register_mutex);
 443         client = synths[card->number];
 444         if (client == NULL || client->ports[device] == NULL) {
 445                 up(&register_mutex);
 446                 return -ENODEV;
 447         }
 448         ports = client->ports_per_device[device];
 449         client->ports_per_device[device] = 0;
 450         msynth = client->ports[device];
 451         client->ports[device] = NULL;
 452         snd_runtime_check(msynth != NULL || ports <= 0, goto __skip);
 453         for (p = 0; p < ports; p++)
 454                 snd_seq_midisynth_delete(&msynth[p]);
 455         kfree(msynth);
 456       __skip:
 457         client->num_ports--;
 458         if (client->num_ports <= 0) {
 459                 snd_seq_delete_kernel_client(client->seq_client);
 460                 synths[card->number] = NULL;
 461                 kfree(client);
 462         }
 463         up(&register_mutex);
 464         return 0;
 465 }
 466
 467
 468 static int __init alsa_seq_midi_init(void)
 469 {
 470         static snd_seq_dev_ops_t ops = {
 471                 snd_seq_midisynth_register_port,
 472                 snd_seq_midisynth_unregister_port,
 473         };
 474         memset(&synths, 0, sizeof(synths));
 475         snd_seq_autoload_lock();
 476         snd_seq_device_register_driver(SNDRV_SEQ_DEV_ID_MIDISYNTH, &ops, 0);
 477         snd_seq_autoload_unlock();
 478         return 0;
 479 }
 480
 481 static void __exit alsa_seq_midi_exit(void)
 482 {
 483         snd_seq_device_unregister_driver(SNDRV_SEQ_DEV_ID_MIDISYNTH);
 484 }
 485
 486 module_init(alsa_seq_midi_init)
 487 module_exit(alsa_seq_midi_exit)