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/module.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         if (snd_BUG_ON(!substream || !buf))
 120                 return -EINVAL;
 121         runtime = substream->runtime;
 122         if ((tmp = runtime->avail) < count) {
 123                 if (printk_ratelimit())
 124                         pr_err("ALSA: seq_midi: MIDI output buffer overrun\n");
 125                 return -ENOMEM;
 126         }
 127         if (snd_rawmidi_kernel_write(substream, buf, count) < count)
 128                 return -EINVAL;
 129         return 0;
 130 }
 131
 132 static int event_process_midi(struct snd_seq_event *ev, int direct,
 133                               void *private_data, int atomic, int hop)
 134 {
 135         struct seq_midisynth *msynth = private_data;
 136         unsigned char msg[10];  /* buffer for constructing midi messages */
 137         struct snd_rawmidi_substream *substream;
 138         int len;
 139
 140         if (snd_BUG_ON(!msynth))
 141                 return -EINVAL;
 142         substream = msynth->output_rfile.output;
 143         if (substream == NULL)
 144                 return -ENODEV;
 145         if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {        /* special case, to save space */
 146                 if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE) {
 147                         /* invalid event */
 148                         pr_debug("ALSA: seq_midi: invalid sysex event flags = 0x%x\n", ev->flags);
 149                         return 0;
 150                 }
 151                 snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)dump_midi, substream);
 152                 snd_midi_event_reset_decode(msynth->parser);
 153         } else {
 154                 if (msynth->parser == NULL)
 155                         return -EIO;
 156                 len = snd_midi_event_decode(msynth->parser, msg, sizeof(msg), ev);
 157                 if (len < 0)
 158                         return 0;
 159                 if (dump_midi(substream, msg, len) < 0)
 160                         snd_midi_event_reset_decode(msynth->parser);
 161         }
 162         return 0;
 163 }
 164
 165
 166 static int snd_seq_midisynth_new(struct seq_midisynth *msynth,
 167                                  struct snd_card *card,
 168                                  int device,
 169                                  int subdevice)
 170 {
 171         if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &msynth->parser) < 0)
 172                 return -ENOMEM;
 173         msynth->card = card;
 174         msynth->device = device;
 175         msynth->subdevice = subdevice;
 176         return 0;
 177 }
 178
 179 /* open associated midi device for input */
 180 static int midisynth_subscribe(void *private_data, struct snd_seq_port_subscribe *info)
 181 {
 182         int err;
 183         struct seq_midisynth *msynth = private_data;
 184         struct snd_rawmidi_runtime *runtime;
 185         struct snd_rawmidi_params params;
 186
 187         /* open midi port */
 188         if ((err = snd_rawmidi_kernel_open(msynth->card, msynth->device,
 189                                            msynth->subdevice,
 190                                            SNDRV_RAWMIDI_LFLG_INPUT,
 191                                            &msynth->input_rfile)) < 0) {
 192                 pr_debug("ALSA: seq_midi: midi input open failed!!!\n");
 193                 return err;
 194         }
 195         runtime = msynth->input_rfile.input->runtime;
 196         memset(&params, 0, sizeof(params));
 197         params.avail_min = 1;
 198         params.buffer_size = input_buffer_size;
 199         if ((err = snd_rawmidi_input_params(msynth->input_rfile.input, &params)) < 0) {
 200                 snd_rawmidi_kernel_release(&msynth->input_rfile);
 201                 return err;
 202         }
 203         snd_midi_event_reset_encode(msynth->parser);
 204         runtime->event = snd_midi_input_event;
 205         runtime->private_data = msynth;
 206         snd_rawmidi_kernel_read(msynth->input_rfile.input, NULL, 0);
 207         return 0;
 208 }
 209
 210 /* close associated midi device for input */
 211 static int midisynth_unsubscribe(void *private_data, struct snd_seq_port_subscribe *info)
 212 {
 213         int err;
 214         struct seq_midisynth *msynth = private_data;
 215
 216         if (snd_BUG_ON(!msynth->input_rfile.input))
 217                 return -EINVAL;
 218         err = snd_rawmidi_kernel_release(&msynth->input_rfile);
 219         return err;
 220 }
 221
 222 /* open associated midi device for output */
 223 static int midisynth_use(void *private_data, struct snd_seq_port_subscribe *info)
 224 {
 225         int err;
 226         struct seq_midisynth *msynth = private_data;
 227         struct snd_rawmidi_params params;
 228
 229         /* open midi port */
 230         if ((err = snd_rawmidi_kernel_open(msynth->card, msynth->device,
 231                                            msynth->subdevice,
 232                                            SNDRV_RAWMIDI_LFLG_OUTPUT,
 233                                            &msynth->output_rfile)) < 0) {
 234                 pr_debug("ALSA: seq_midi: midi output open failed!!!\n");
 235                 return err;
 236         }
 237         memset(&params, 0, sizeof(params));
 238         params.avail_min = 1;
 239         params.buffer_size = output_buffer_size;
 240         params.no_active_sensing = 1;
 241         if ((err = snd_rawmidi_output_params(msynth->output_rfile.output, &params)) < 0) {
 242                 snd_rawmidi_kernel_release(&msynth->output_rfile);
 243                 return err;
 244         }
 245         snd_midi_event_reset_decode(msynth->parser);
 246         return 0;
 247 }
 248
 249 /* close associated midi device for output */
 250 static int midisynth_unuse(void *private_data, struct snd_seq_port_subscribe *info)
 251 {
 252         struct seq_midisynth *msynth = private_data;
 253
 254         if (snd_BUG_ON(!msynth->output_rfile.output))
 255                 return -EINVAL;
 256         snd_rawmidi_drain_output(msynth->output_rfile.output);
 257         return snd_rawmidi_kernel_release(&msynth->output_rfile);
 258 }
 259
 260 /* delete given midi synth port */
 261 static void snd_seq_midisynth_delete(struct seq_midisynth *msynth)
 262 {
 263         if (msynth == NULL)
 264                 return;
 265
 266         if (msynth->seq_client > 0) {
 267                 /* delete port */
 268                 snd_seq_event_port_detach(msynth->seq_client, msynth->seq_port);
 269         }
 270
 271         snd_midi_event_free(msynth->parser);
 272 }
 273
 274 /* register new midi synth port */
 275 static int
 276 snd_seq_midisynth_probe(struct device *_dev)
 277 {
 278         struct snd_seq_device *dev = to_seq_dev(_dev);
 279         struct seq_midisynth_client *client;
 280         struct seq_midisynth *msynth, *ms;
 281         struct snd_seq_port_info *port;
 282         struct snd_rawmidi_info *info;
 283         struct snd_rawmidi *rmidi = dev->private_data;
 284         int newclient = 0;
 285         unsigned int p, ports;
 286         struct snd_seq_port_callback pcallbacks;
 287         struct snd_card *card = dev->card;
 288         int device = dev->device;
 289         unsigned int input_count = 0, output_count = 0;
 290
 291         if (snd_BUG_ON(!card || device < 0 || device >= SNDRV_RAWMIDI_DEVICES))
 292                 return -EINVAL;
 293         info = kmalloc(sizeof(*info), GFP_KERNEL);
 294         if (! info)
 295                 return -ENOMEM;
 296         info->device = device;
 297         info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
 298         info->subdevice = 0;
 299         if (snd_rawmidi_info_select(card, info) >= 0)
 300                 output_count = info->subdevices_count;
 301         info->stream = SNDRV_RAWMIDI_STREAM_INPUT;
 302         if (snd_rawmidi_info_select(card, info) >= 0) {
 303                 input_count = info->subdevices_count;
 304         }
 305         ports = output_count;
 306         if (ports < input_count)
 307                 ports = input_count;
 308         if (ports == 0) {
 309                 kfree(info);
 310                 return -ENODEV;
 311         }
 312         if (ports > (256 / SNDRV_RAWMIDI_DEVICES))
 313                 ports = 256 / SNDRV_RAWMIDI_DEVICES;
 314
 315         mutex_lock(&register_mutex);
 316         client = synths[card->number];
 317         if (client == NULL) {
 318                 newclient = 1;
 319                 client = kzalloc(sizeof(*client), GFP_KERNEL);
 320                 if (client == NULL) {
 321                         mutex_unlock(&register_mutex);
 322                         kfree(info);
 323                         return -ENOMEM;
 324                 }
 325                 client->seq_client =
 326                         snd_seq_create_kernel_client(
 327                                 card, 0, "%s", card->shortname[0] ?
 328                                 (const char *)card->shortname : "External MIDI");
 329                 if (client->seq_client < 0) {
 330                         kfree(client);
 331                         mutex_unlock(&register_mutex);
 332                         kfree(info);
 333                         return -ENOMEM;
 334                 }
 335         }
 336
 337         msynth = kcalloc(ports, sizeof(struct seq_midisynth), GFP_KERNEL);
 338         port = kmalloc(sizeof(*port), GFP_KERNEL);
 339         if (msynth == NULL || port == NULL)
 340                 goto __nomem;
 341
 342         for (p = 0; p < ports; p++) {
 343                 ms = &msynth[p];
 344
 345                 if (snd_seq_midisynth_new(ms, card, device, p) < 0)
 346                         goto __nomem;
 347
 348                 /* declare port */
 349                 memset(port, 0, sizeof(*port));
 350                 port->addr.client = client->seq_client;
 351                 port->addr.port = device * (256 / SNDRV_RAWMIDI_DEVICES) + p;
 352                 port->flags = SNDRV_SEQ_PORT_FLG_GIVEN_PORT;
 353                 memset(info, 0, sizeof(*info));
 354                 info->device = device;
 355                 if (p < output_count)
 356                         info->stream = SNDRV_RAWMIDI_STREAM_OUTPUT;
 357                 else
 358                         info->stream = SNDRV_RAWMIDI_STREAM_INPUT;
 359                 info->subdevice = p;
 360                 if (snd_rawmidi_info_select(card, info) >= 0)
 361                         strcpy(port->name, info->subname);
 362                 if (! port->name[0]) {
 363                         if (info->name[0]) {
 364                                 if (ports > 1)
 365                                         snprintf(port->name, sizeof(port->name), "%s-%u", info->name, p);
 366                                 else
 367                                         snprintf(port->name, sizeof(port->name), "%s", info->name);
 368                         } else {
 369                                 /* last resort */
 370                                 if (ports > 1)
 371                                         sprintf(port->name, "MIDI %d-%d-%u", card->number, device, p);
 372                                 else
 373                                         sprintf(port->name, "MIDI %d-%d", card->number, device);
 374                         }
 375                 }
 376                 if ((info->flags & SNDRV_RAWMIDI_INFO_OUTPUT) && p < output_count)
 377                         port->capability |= SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SYNC_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE;
 378                 if ((info->flags & SNDRV_RAWMIDI_INFO_INPUT) && p < input_count)
 379                         port->capability |= SNDRV_SEQ_PORT_CAP_READ | SNDRV_SEQ_PORT_CAP_SYNC_READ | SNDRV_SEQ_PORT_CAP_SUBS_READ;
 380                 if ((port->capability & (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ)) == (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_READ) &&
 381                     info->flags & SNDRV_RAWMIDI_INFO_DUPLEX)
 382                         port->capability |= SNDRV_SEQ_PORT_CAP_DUPLEX;
 383                 port->type = SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC
 384                         | SNDRV_SEQ_PORT_TYPE_HARDWARE
 385                         | SNDRV_SEQ_PORT_TYPE_PORT;
 386                 port->midi_channels = 16;
 387                 memset(&pcallbacks, 0, sizeof(pcallbacks));
 388                 pcallbacks.owner = THIS_MODULE;
 389                 pcallbacks.private_data = ms;
 390                 pcallbacks.subscribe = midisynth_subscribe;
 391                 pcallbacks.unsubscribe = midisynth_unsubscribe;
 392                 pcallbacks.use = midisynth_use;
 393                 pcallbacks.unuse = midisynth_unuse;
 394                 pcallbacks.event_input = event_process_midi;
 395                 port->kernel = &pcallbacks;
 396                 if (rmidi->ops && rmidi->ops->get_port_info)
 397                         rmidi->ops->get_port_info(rmidi, p, port);
 398                 if (snd_seq_kernel_client_ctl(client->seq_client, SNDRV_SEQ_IOCTL_CREATE_PORT, port)<0)
 399                         goto __nomem;
 400                 ms->seq_client = client->seq_client;
 401                 ms->seq_port = port->addr.port;
 402         }
 403         client->ports_per_device[device] = ports;
 404         client->ports[device] = msynth;
 405         client->num_ports++;
 406         if (newclient)
 407                 synths[card->number] = client;
 408         mutex_unlock(&register_mutex);
 409         kfree(info);
 410         kfree(port);
 411         return 0;       /* success */
 412
 413       __nomem:
 414         if (msynth != NULL) {
 415                 for (p = 0; p < ports; p++)
 416                         snd_seq_midisynth_delete(&msynth[p]);
 417                 kfree(msynth);
 418         }
 419         if (newclient) {
 420                 snd_seq_delete_kernel_client(client->seq_client);
 421                 kfree(client);
 422         }
 423         kfree(info);
 424         kfree(port);
 425         mutex_unlock(&register_mutex);
 426         return -ENOMEM;
 427 }
 428
 429 /* release midi synth port */
 430 static int
 431 snd_seq_midisynth_remove(struct device *_dev)
 432 {
 433         struct snd_seq_device *dev = to_seq_dev(_dev);
 434         struct seq_midisynth_client *client;
 435         struct seq_midisynth *msynth;
 436         struct snd_card *card = dev->card;
 437         int device = dev->device, p, ports;
 438
 439         mutex_lock(&register_mutex);
 440         client = synths[card->number];
 441         if (client == NULL || client->ports[device] == NULL) {
 442                 mutex_unlock(&register_mutex);
 443                 return -ENODEV;
 444         }
 445         ports = client->ports_per_device[device];
 446         client->ports_per_device[device] = 0;
 447         msynth = client->ports[device];
 448         client->ports[device] = NULL;
 449         for (p = 0; p < ports; p++)
 450                 snd_seq_midisynth_delete(&msynth[p]);
 451         kfree(msynth);
 452         client->num_ports--;
 453         if (client->num_ports <= 0) {
 454                 snd_seq_delete_kernel_client(client->seq_client);
 455                 synths[card->number] = NULL;
 456                 kfree(client);
 457         }
 458         mutex_unlock(&register_mutex);
 459         return 0;
 460 }
 461
 462 static struct snd_seq_driver seq_midisynth_driver = {
 463         .driver = {
 464                 .name = KBUILD_MODNAME,
 465                 .probe = snd_seq_midisynth_probe,
 466                 .remove = snd_seq_midisynth_remove,
 467         },
 468         .id = SNDRV_SEQ_DEV_ID_MIDISYNTH,
 469         .argsize = 0,
 470 };
 471
 472 module_snd_seq_driver(seq_midisynth_driver);