sound/core/seq/seq_midi_event.c

   1 /*
   2  *  MIDI byte <-> sequencer event coder
   3  *
   4  *  Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>,
   5  *                        Jaroslav Kysela <perex@suse.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 #include <sound/driver.h>
  23 #include <linux/slab.h>
  24 #include <linux/errno.h>
  25 #include <linux/string.h>
  26 #include <sound/core.h>
  27 #include <sound/seq_kernel.h>
  28 #include <sound/seq_midi_event.h>
  29 #include <sound/asoundef.h>
  30
  31 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>, Jaroslav Kysela <perex@suse.cz>");
  32 MODULE_DESCRIPTION("MIDI byte <-> sequencer event coder");
  33 MODULE_LICENSE("GPL");
  34
  35 /* queue type */
  36 /* from 0 to 7 are normal commands (note off, on, etc.) */
  37 #define ST_NOTEOFF      0
  38 #define ST_NOTEON       1
  39 #define ST_SPECIAL      8
  40 #define ST_SYSEX        ST_SPECIAL
  41 /* from 8 to 15 are events for 0xf0-0xf7 */
  42
  43
  44 /* status event types */
  45 typedef void (*event_encode_t)(snd_midi_event_t *dev, snd_seq_event_t *ev);
  46 typedef void (*event_decode_t)(snd_seq_event_t *ev, unsigned char *buf);
  47
  48 /*
  49  * prototypes
  50  */
  51 static void note_event(snd_midi_event_t *dev, snd_seq_event_t *ev);
  52 static void one_param_ctrl_event(snd_midi_event_t *dev, snd_seq_event_t *ev);
  53 static void pitchbend_ctrl_event(snd_midi_event_t *dev, snd_seq_event_t *ev);
  54 static void two_param_ctrl_event(snd_midi_event_t *dev, snd_seq_event_t *ev);
  55 static void one_param_event(snd_midi_event_t *dev, snd_seq_event_t *ev);
  56 static void songpos_event(snd_midi_event_t *dev, snd_seq_event_t *ev);
  57 static void note_decode(snd_seq_event_t *ev, unsigned char *buf);
  58 static void one_param_decode(snd_seq_event_t *ev, unsigned char *buf);
  59 static void pitchbend_decode(snd_seq_event_t *ev, unsigned char *buf);
  60 static void two_param_decode(snd_seq_event_t *ev, unsigned char *buf);
  61 static void songpos_decode(snd_seq_event_t *ev, unsigned char *buf);
  62
  63 /*
  64  * event list
  65  */
  66 static struct status_event_list_t {
  67         int event;
  68         int qlen;
  69         event_encode_t encode;
  70         event_decode_t decode;
  71 } status_event[] = {
  72         /* 0x80 - 0xf0 */
  73         {SNDRV_SEQ_EVENT_NOTEOFF,       2, note_event, note_decode},
  74         {SNDRV_SEQ_EVENT_NOTEON,        2, note_event, note_decode},
  75         {SNDRV_SEQ_EVENT_KEYPRESS,      2, note_event, note_decode},
  76         {SNDRV_SEQ_EVENT_CONTROLLER,    2, two_param_ctrl_event, two_param_decode},
  77         {SNDRV_SEQ_EVENT_PGMCHANGE,     1, one_param_ctrl_event, one_param_decode},
  78         {SNDRV_SEQ_EVENT_CHANPRESS,     1, one_param_ctrl_event, one_param_decode},
  79         {SNDRV_SEQ_EVENT_PITCHBEND,     2, pitchbend_ctrl_event, pitchbend_decode},
  80         {SNDRV_SEQ_EVENT_NONE,          0, NULL, NULL}, /* 0xf0 */
  81         /* 0xf0 - 0xff */
  82         {SNDRV_SEQ_EVENT_SYSEX,         1, NULL, NULL}, /* sysex: 0xf0 */
  83         {SNDRV_SEQ_EVENT_QFRAME,        1, one_param_event, one_param_decode}, /* 0xf1 */
  84         {SNDRV_SEQ_EVENT_SONGPOS,       2, songpos_event, songpos_decode}, /* 0xf2 */
  85         {SNDRV_SEQ_EVENT_SONGSEL,       1, one_param_event, one_param_decode}, /* 0xf3 */
  86         {SNDRV_SEQ_EVENT_NONE,          0, NULL, NULL}, /* 0xf4 */
  87         {SNDRV_SEQ_EVENT_NONE,          0, NULL, NULL}, /* 0xf5 */
  88         {SNDRV_SEQ_EVENT_TUNE_REQUEST,  0, NULL, NULL}, /* 0xf6 */
  89         {SNDRV_SEQ_EVENT_NONE,          0, NULL, NULL}, /* 0xf7 */
  90         {SNDRV_SEQ_EVENT_CLOCK,         0, NULL, NULL}, /* 0xf8 */
  91         {SNDRV_SEQ_EVENT_NONE,          0, NULL, NULL}, /* 0xf9 */
  92         {SNDRV_SEQ_EVENT_START,         0, NULL, NULL}, /* 0xfa */
  93         {SNDRV_SEQ_EVENT_CONTINUE,      0, NULL, NULL}, /* 0xfb */
  94         {SNDRV_SEQ_EVENT_STOP,          0, NULL, NULL}, /* 0xfc */
  95         {SNDRV_SEQ_EVENT_NONE,          0, NULL, NULL}, /* 0xfd */
  96         {SNDRV_SEQ_EVENT_SENSING,       0, NULL, NULL}, /* 0xfe */
  97         {SNDRV_SEQ_EVENT_RESET,         0, NULL, NULL}, /* 0xff */
  98 };
  99
 100 static int extra_decode_ctrl14(snd_midi_event_t *dev, unsigned char *buf, int len, snd_seq_event_t *ev);
 101 static int extra_decode_xrpn(snd_midi_event_t *dev, unsigned char *buf, int count, snd_seq_event_t *ev);
 102
 103 static struct extra_event_list_t {
 104         int event;
 105         int (*decode)(snd_midi_event_t *dev, unsigned char *buf, int len, snd_seq_event_t *ev);
 106 } extra_event[] = {
 107         {SNDRV_SEQ_EVENT_CONTROL14, extra_decode_ctrl14},
 108         {SNDRV_SEQ_EVENT_NONREGPARAM, extra_decode_xrpn},
 109         {SNDRV_SEQ_EVENT_REGPARAM, extra_decode_xrpn},
 110 };
 111
 112 /*
 113  *  new/delete record
 114  */
 115
 116 int snd_midi_event_new(int bufsize, snd_midi_event_t **rdev)
 117 {
 118         snd_midi_event_t *dev;
 119
 120         *rdev = NULL;
 121         dev = kcalloc(1, sizeof(*dev), GFP_KERNEL);
 122         if (dev == NULL)
 123                 return -ENOMEM;
 124         if (bufsize > 0) {
 125                 dev->buf = kmalloc(bufsize, GFP_KERNEL);
 126                 if (dev->buf == NULL) {
 127                         kfree(dev);
 128                         return -ENOMEM;
 129                 }
 130         }
 131         dev->bufsize = bufsize;
 132         dev->lastcmd = 0xff;
 133         spin_lock_init(&dev->lock);
 134         *rdev = dev;
 135         return 0;
 136 }
 137
 138 void snd_midi_event_free(snd_midi_event_t *dev)
 139 {
 140         if (dev != NULL) {
 141                 kfree(dev->buf);
 142                 kfree(dev);
 143         }
 144 }
 145
 146 /*
 147  * initialize record
 148  */
 149 static inline void reset_encode(snd_midi_event_t *dev)
 150 {
 151         dev->read = 0;
 152         dev->qlen = 0;
 153         dev->type = 0;
 154 }
 155
 156 void snd_midi_event_reset_encode(snd_midi_event_t *dev)
 157 {
 158         unsigned long flags;
 159
 160         spin_lock_irqsave(&dev->lock, flags);
 161         reset_encode(dev);
 162         spin_unlock_irqrestore(&dev->lock, flags);
 163 }
 164
 165 void snd_midi_event_reset_decode(snd_midi_event_t *dev)
 166 {
 167         unsigned long flags;
 168
 169         spin_lock_irqsave(&dev->lock, flags);
 170         dev->lastcmd = 0xff;
 171         spin_unlock_irqrestore(&dev->lock, flags);
 172 }
 173
 174 #if 0
 175 void snd_midi_event_init(snd_midi_event_t *dev)
 176 {
 177         snd_midi_event_reset_encode(dev);
 178         snd_midi_event_reset_decode(dev);
 179 }
 180 #endif  /*  0  */
 181
 182 void snd_midi_event_no_status(snd_midi_event_t *dev, int on)
 183 {
 184         dev->nostat = on ? 1 : 0;
 185 }
 186
 187 /*
 188  * resize buffer
 189  */
 190 #if 0
 191 int snd_midi_event_resize_buffer(snd_midi_event_t *dev, int bufsize)
 192 {
 193         unsigned char *new_buf, *old_buf;
 194         unsigned long flags;
 195
 196         if (bufsize == dev->bufsize)
 197                 return 0;
 198         new_buf = kmalloc(bufsize, GFP_KERNEL);
 199         if (new_buf == NULL)
 200                 return -ENOMEM;
 201         spin_lock_irqsave(&dev->lock, flags);
 202         old_buf = dev->buf;
 203         dev->buf = new_buf;
 204         dev->bufsize = bufsize;
 205         reset_encode(dev);
 206         spin_unlock_irqrestore(&dev->lock, flags);
 207         kfree(old_buf);
 208         return 0;
 209 }
 210 #endif  /*  0  */
 211
 212 /*
 213  *  read bytes and encode to sequencer event if finished
 214  *  return the size of encoded bytes
 215  */
 216 long snd_midi_event_encode(snd_midi_event_t *dev, unsigned char *buf, long count, snd_seq_event_t *ev)
 217 {
 218         long result = 0;
 219         int rc;
 220
 221         ev->type = SNDRV_SEQ_EVENT_NONE;
 222
 223         while (count-- > 0) {
 224                 rc = snd_midi_event_encode_byte(dev, *buf++, ev);
 225                 result++;
 226                 if (rc < 0)
 227                         return rc;
 228                 else if (rc > 0)
 229                         return result;
 230         }
 231
 232         return result;
 233 }
 234
 235 /*
 236  *  read one byte and encode to sequencer event:
 237  *  return 1 if MIDI bytes are encoded to an event
 238  *         0 data is not finished
 239  *         negative for error
 240  */
 241 int snd_midi_event_encode_byte(snd_midi_event_t *dev, int c, snd_seq_event_t *ev)
 242 {
 243         int rc = 0;
 244         unsigned long flags;
 245
 246         c &= 0xff;
 247
 248         if (c >= MIDI_CMD_COMMON_CLOCK) {
 249                 /* real-time event */
 250                 ev->type = status_event[ST_SPECIAL + c - 0xf0].event;
 251                 ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
 252                 ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
 253                 return 1;
 254         }
 255
 256         spin_lock_irqsave(&dev->lock, flags);
 257         if (dev->qlen > 0) {
 258                 /* rest of command */
 259                 dev->buf[dev->read++] = c;
 260                 if (dev->type != ST_SYSEX)
 261                         dev->qlen--;
 262         } else {
 263                 /* new command */
 264                 dev->read = 1;
 265                 if (c & 0x80) {
 266                         dev->buf[0] = c;
 267                         if ((c & 0xf0) == 0xf0) /* special events */
 268                                 dev->type = (c & 0x0f) + ST_SPECIAL;
 269                         else
 270                                 dev->type = (c >> 4) & 0x07;
 271                         dev->qlen = status_event[dev->type].qlen;
 272                 } else {
 273                         /* process this byte as argument */
 274                         dev->buf[dev->read++] = c;
 275                         dev->qlen = status_event[dev->type].qlen - 1;
 276                 }
 277         }
 278         if (dev->qlen == 0) {
 279                 ev->type = status_event[dev->type].event;
 280                 ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
 281                 ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
 282                 if (status_event[dev->type].encode) /* set data values */
 283                         status_event[dev->type].encode(dev, ev);
 284                 rc = 1;
 285         } else  if (dev->type == ST_SYSEX) {
 286                 if (c == MIDI_CMD_COMMON_SYSEX_END ||
 287                     dev->read >= dev->bufsize) {
 288                         ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
 289                         ev->flags |= SNDRV_SEQ_EVENT_LENGTH_VARIABLE;
 290                         ev->type = SNDRV_SEQ_EVENT_SYSEX;
 291                         ev->data.ext.len = dev->read;
 292                         ev->data.ext.ptr = dev->buf;
 293                         if (c != MIDI_CMD_COMMON_SYSEX_END)
 294                                 dev->read = 0; /* continue to parse */
 295                         else
 296                                 reset_encode(dev); /* all parsed */
 297                         rc = 1;
 298                 }
 299         }
 300
 301         spin_unlock_irqrestore(&dev->lock, flags);
 302         return rc;
 303 }
 304
 305 /* encode note event */
 306 static void note_event(snd_midi_event_t *dev, snd_seq_event_t *ev)
 307 {
 308         ev->data.note.channel = dev->buf[0] & 0x0f;
 309         ev->data.note.note = dev->buf[1];
 310         ev->data.note.velocity = dev->buf[2];
 311 }
 312
 313 /* encode one parameter controls */
 314 static void one_param_ctrl_event(snd_midi_event_t *dev, snd_seq_event_t *ev)
 315 {
 316         ev->data.control.channel = dev->buf[0] & 0x0f;
 317         ev->data.control.value = dev->buf[1];
 318 }
 319
 320 /* encode pitch wheel change */
 321 static void pitchbend_ctrl_event(snd_midi_event_t *dev, snd_seq_event_t *ev)
 322 {
 323         ev->data.control.channel = dev->buf[0] & 0x0f;
 324         ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1] - 8192;
 325 }
 326
 327 /* encode midi control change */
 328 static void two_param_ctrl_event(snd_midi_event_t *dev, snd_seq_event_t *ev)
 329 {
 330         ev->data.control.channel = dev->buf[0] & 0x0f;
 331         ev->data.control.param = dev->buf[1];
 332         ev->data.control.value = dev->buf[2];
 333 }
 334
 335 /* encode one parameter value*/
 336 static void one_param_event(snd_midi_event_t *dev, snd_seq_event_t *ev)
 337 {
 338         ev->data.control.value = dev->buf[1];
 339 }
 340
 341 /* encode song position */
 342 static void songpos_event(snd_midi_event_t *dev, snd_seq_event_t *ev)
 343 {
 344         ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1];
 345 }
 346
 347 /*
 348  * decode from a sequencer event to midi bytes
 349  * return the size of decoded midi events
 350  */
 351 long snd_midi_event_decode(snd_midi_event_t *dev, unsigned char *buf, long count, snd_seq_event_t *ev)
 352 {
 353         unsigned int cmd, type;
 354
 355         if (ev->type == SNDRV_SEQ_EVENT_NONE)
 356                 return -ENOENT;
 357
 358         for (type = 0; type < ARRAY_SIZE(status_event); type++) {
 359                 if (ev->type == status_event[type].event)
 360                         goto __found;
 361         }
 362         for (type = 0; type < ARRAY_SIZE(extra_event); type++) {
 363                 if (ev->type == extra_event[type].event)
 364                         return extra_event[type].decode(dev, buf, count, ev);
 365         }
 366         return -ENOENT;
 367
 368       __found:
 369         if (type >= ST_SPECIAL)
 370                 cmd = 0xf0 + (type - ST_SPECIAL);
 371         else
 372                 /* data.note.channel and data.control.channel is identical */
 373                 cmd = 0x80 | (type << 4) | (ev->data.note.channel & 0x0f);
 374
 375
 376         if (cmd == MIDI_CMD_COMMON_SYSEX) {
 377                 snd_midi_event_reset_decode(dev);
 378                 return snd_seq_expand_var_event(ev, count, buf, 1, 0);
 379         } else {
 380                 int qlen;
 381                 unsigned char xbuf[4];
 382                 unsigned long flags;
 383
 384                 spin_lock_irqsave(&dev->lock, flags);
 385                 if ((cmd & 0xf0) == 0xf0 || dev->lastcmd != cmd || dev->nostat) {
 386                         dev->lastcmd = cmd;
 387                         spin_unlock_irqrestore(&dev->lock, flags);
 388                         xbuf[0] = cmd;
 389                         if (status_event[type].decode)
 390                                 status_event[type].decode(ev, xbuf + 1);
 391                         qlen = status_event[type].qlen + 1;
 392                 } else {
 393                         spin_unlock_irqrestore(&dev->lock, flags);
 394                         if (status_event[type].decode)
 395                                 status_event[type].decode(ev, xbuf + 0);
 396                         qlen = status_event[type].qlen;
 397                 }
 398                 if (count < qlen)
 399                         return -ENOMEM;
 400                 memcpy(buf, xbuf, qlen);
 401                 return qlen;
 402         }
 403 }
 404
 405
 406 /* decode note event */
 407 static void note_decode(snd_seq_event_t *ev, unsigned char *buf)
 408 {
 409         buf[0] = ev->data.note.note & 0x7f;
 410         buf[1] = ev->data.note.velocity & 0x7f;
 411 }
 412
 413 /* decode one parameter controls */
 414 static void one_param_decode(snd_seq_event_t *ev, unsigned char *buf)
 415 {
 416         buf[0] = ev->data.control.value & 0x7f;
 417 }
 418
 419 /* decode pitch wheel change */
 420 static void pitchbend_decode(snd_seq_event_t *ev, unsigned char *buf)
 421 {
 422         int value = ev->data.control.value + 8192;
 423         buf[0] = value & 0x7f;
 424         buf[1] = (value >> 7) & 0x7f;
 425 }
 426
 427 /* decode midi control change */
 428 static void two_param_decode(snd_seq_event_t *ev, unsigned char *buf)
 429 {
 430         buf[0] = ev->data.control.param & 0x7f;
 431         buf[1] = ev->data.control.value & 0x7f;
 432 }
 433
 434 /* decode song position */
 435 static void songpos_decode(snd_seq_event_t *ev, unsigned char *buf)
 436 {
 437         buf[0] = ev->data.control.value & 0x7f;
 438         buf[1] = (ev->data.control.value >> 7) & 0x7f;
 439 }
 440
 441 /* decode 14bit control */
 442 static int extra_decode_ctrl14(snd_midi_event_t *dev, unsigned char *buf, int count, snd_seq_event_t *ev)
 443 {
 444         unsigned char cmd;
 445         int idx = 0;
 446
 447         cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);
 448         if (ev->data.control.param < 0x20) {
 449                 if (count < 4)
 450                         return -ENOMEM;
 451                 if (dev->nostat && count < 6)
 452                         return -ENOMEM;
 453                 if (cmd != dev->lastcmd || dev->nostat) {
 454                         if (count < 5)
 455                                 return -ENOMEM;
 456                         buf[idx++] = dev->lastcmd = cmd;
 457                 }
 458                 buf[idx++] = ev->data.control.param;
 459                 buf[idx++] = (ev->data.control.value >> 7) & 0x7f;
 460                 if (dev->nostat)
 461                         buf[idx++] = cmd;
 462                 buf[idx++] = ev->data.control.param + 0x20;
 463                 buf[idx++] = ev->data.control.value & 0x7f;
 464         } else {
 465                 if (count < 2)
 466                         return -ENOMEM;
 467                 if (cmd != dev->lastcmd || dev->nostat) {
 468                         if (count < 3)
 469                                 return -ENOMEM;
 470                         buf[idx++] = dev->lastcmd = cmd;
 471                 }
 472                 buf[idx++] = ev->data.control.param & 0x7f;
 473                 buf[idx++] = ev->data.control.value & 0x7f;
 474         }
 475         return idx;
 476 }
 477
 478 /* decode reg/nonreg param */
 479 static int extra_decode_xrpn(snd_midi_event_t *dev, unsigned char *buf, int count, snd_seq_event_t *ev)
 480 {
 481         unsigned char cmd;
 482         char *cbytes;
 483         static char cbytes_nrpn[4] = { MIDI_CTL_NONREG_PARM_NUM_MSB,
 484                                        MIDI_CTL_NONREG_PARM_NUM_LSB,
 485                                        MIDI_CTL_MSB_DATA_ENTRY,
 486                                        MIDI_CTL_LSB_DATA_ENTRY };
 487         static char cbytes_rpn[4] =  { MIDI_CTL_REGIST_PARM_NUM_MSB,
 488                                        MIDI_CTL_REGIST_PARM_NUM_LSB,
 489                                        MIDI_CTL_MSB_DATA_ENTRY,
 490                                        MIDI_CTL_LSB_DATA_ENTRY };
 491         unsigned char bytes[4];
 492         int idx = 0, i;
 493
 494         if (count < 8)
 495                 return -ENOMEM;
 496         if (dev->nostat && count < 12)
 497                 return -ENOMEM;
 498         cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);
 499         bytes[0] = ev->data.control.param & 0x007f;
 500         bytes[1] = (ev->data.control.param & 0x3f80) >> 7;
 501         bytes[2] = ev->data.control.value & 0x007f;
 502         bytes[3] = (ev->data.control.value & 0x3f80) >> 7;
 503         if (cmd != dev->lastcmd && !dev->nostat) {
 504                 if (count < 9)
 505                         return -ENOMEM;
 506                 buf[idx++] = dev->lastcmd = cmd;
 507         }
 508         cbytes = ev->type == SNDRV_SEQ_EVENT_NONREGPARAM ? cbytes_nrpn : cbytes_rpn;
 509         for (i = 0; i < 4; i++) {
 510                 if (dev->nostat)
 511                         buf[idx++] = dev->lastcmd = cmd;
 512                 buf[idx++] = cbytes[i];
 513                 buf[idx++] = bytes[i];
 514         }
 515         return idx;
 516 }
 517
 518 /*
 519  *  exports
 520  */
 521
 522 EXPORT_SYMBOL(snd_midi_event_new);
 523 EXPORT_SYMBOL(snd_midi_event_free);
 524 EXPORT_SYMBOL(snd_midi_event_reset_encode);
 525 EXPORT_SYMBOL(snd_midi_event_reset_decode);
 526 EXPORT_SYMBOL(snd_midi_event_no_status);
 527 EXPORT_SYMBOL(snd_midi_event_encode);
 528 EXPORT_SYMBOL(snd_midi_event_encode_byte);
 529 EXPORT_SYMBOL(snd_midi_event_decode);
 530
 531 static int __init alsa_seq_midi_event_init(void)
 532 {
 533         return 0;
 534 }
 535
 536 static void __exit alsa_seq_midi_event_exit(void)
 537 {
 538 }
 539
 540 module_init(alsa_seq_midi_event_init)
 541 module_exit(alsa_seq_midi_event_exit)