1 /*
2 * MIDI byte <-> sequencer event coder
3 *
4 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>,
5 * Jaroslav Kysela <perex@perex.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 <linux/slab.h>
23 #include <linux/errno.h>
24 #include <linux/string.h>
25 #include <linux/module.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@perex.cz>");
32 MODULE_DESCRIPTION("MIDI byte <-> sequencer event coder");
33 MODULE_LICENSE("GPL");
34
35 /* event type, index into status_event[] */
36 /* from 0 to 6 are normal commands (note off, on, etc.) for 0x9?-0xe? */
37 #define ST_INVALID 7
38 #define ST_SPECIAL 8
39 #define ST_SYSEX ST_SPECIAL
40 /* from 8 to 15 are events for 0xf0-0xf7 */
41
42
43 /*
44 * prototypes
45 */
46 static void note_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
47 static void one_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
48 static void pitchbend_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
49 static void two_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
50 static void one_param_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
51 static void songpos_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
52 static void note_decode(struct snd_seq_event *ev, unsigned char *buf);
53 static void one_param_decode(struct snd_seq_event *ev, unsigned char *buf);
54 static void pitchbend_decode(struct snd_seq_event *ev, unsigned char *buf);
55 static void two_param_decode(struct snd_seq_event *ev, unsigned char *buf);
56 static void songpos_decode(struct snd_seq_event *ev, unsigned char *buf);
57
58 /*
59 * event list
60 */
61 static struct status_event_list {
62 int event;
63 int qlen;
64 void (*encode)(struct snd_midi_event *dev, struct snd_seq_event *ev);
65 void (*decode)(struct snd_seq_event *ev, unsigned char *buf);
66 } status_event[] = {
67 /* 0x80 - 0xef */
68 {SNDRV_SEQ_EVENT_NOTEOFF, 2, note_event, note_decode},
69 {SNDRV_SEQ_EVENT_NOTEON, 2, note_event, note_decode},
70 {SNDRV_SEQ_EVENT_KEYPRESS, 2, note_event, note_decode},
71 {SNDRV_SEQ_EVENT_CONTROLLER, 2, two_param_ctrl_event, two_param_decode},
72 {SNDRV_SEQ_EVENT_PGMCHANGE, 1, one_param_ctrl_event, one_param_decode},
73 {SNDRV_SEQ_EVENT_CHANPRESS, 1, one_param_ctrl_event, one_param_decode},
74 {SNDRV_SEQ_EVENT_PITCHBEND, 2, pitchbend_ctrl_event, pitchbend_decode},
75 /* invalid */
76 {SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL},
77 /* 0xf0 - 0xff */
78 {SNDRV_SEQ_EVENT_SYSEX, 1, NULL, NULL}, /* sysex: 0xf0 */
79 {SNDRV_SEQ_EVENT_QFRAME, 1, one_param_event, one_param_decode}, /* 0xf1 */
80 {SNDRV_SEQ_EVENT_SONGPOS, 2, songpos_event, songpos_decode}, /* 0xf2 */
81 {SNDRV_SEQ_EVENT_SONGSEL, 1, one_param_event, one_param_decode}, /* 0xf3 */
82 {SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf4 */
83 {SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf5 */
84 {SNDRV_SEQ_EVENT_TUNE_REQUEST, 0, NULL, NULL}, /* 0xf6 */
85 {SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf7 */
86 {SNDRV_SEQ_EVENT_CLOCK, 0, NULL, NULL}, /* 0xf8 */
87 {SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xf9 */
88 {SNDRV_SEQ_EVENT_START, 0, NULL, NULL}, /* 0xfa */
89 {SNDRV_SEQ_EVENT_CONTINUE, 0, NULL, NULL}, /* 0xfb */
90 {SNDRV_SEQ_EVENT_STOP, 0, NULL, NULL}, /* 0xfc */
91 {SNDRV_SEQ_EVENT_NONE, -1, NULL, NULL}, /* 0xfd */
92 {SNDRV_SEQ_EVENT_SENSING, 0, NULL, NULL}, /* 0xfe */
93 {SNDRV_SEQ_EVENT_RESET, 0, NULL, NULL}, /* 0xff */
94 };
95
96 static int extra_decode_ctrl14(struct snd_midi_event *dev, unsigned char *buf, int len,
97 struct snd_seq_event *ev);
98 static int extra_decode_xrpn(struct snd_midi_event *dev, unsigned char *buf, int count,
99 struct snd_seq_event *ev);
100
101 static struct extra_event_list {
102 int event;
103 int (*decode)(struct snd_midi_event *dev, unsigned char *buf, int len,
104 struct snd_seq_event *ev);
105 } extra_event[] = {
106 {SNDRV_SEQ_EVENT_CONTROL14, extra_decode_ctrl14},
107 {SNDRV_SEQ_EVENT_NONREGPARAM, extra_decode_xrpn},
108 {SNDRV_SEQ_EVENT_REGPARAM, extra_decode_xrpn},
109 };
110
111 /*
112 * new/delete record
113 */
114
snd_midi_event_new(int bufsize,struct snd_midi_event ** rdev)115 int snd_midi_event_new(int bufsize, struct snd_midi_event **rdev)
116 {
117 struct snd_midi_event *dev;
118
119 *rdev = NULL;
120 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
121 if (dev == NULL)
122 return -ENOMEM;
123 if (bufsize > 0) {
124 dev->buf = kmalloc(bufsize, GFP_KERNEL);
125 if (dev->buf == NULL) {
126 kfree(dev);
127 return -ENOMEM;
128 }
129 }
130 dev->bufsize = bufsize;
131 dev->lastcmd = 0xff;
132 dev->type = ST_INVALID;
133 spin_lock_init(&dev->lock);
134 *rdev = dev;
135 return 0;
136 }
137
snd_midi_event_free(struct snd_midi_event * dev)138 void snd_midi_event_free(struct snd_midi_event *dev)
139 {
140 if (dev != NULL) {
141 kfree(dev->buf);
142 kfree(dev);
143 }
144 }
145
146 /*
147 * initialize record
148 */
reset_encode(struct snd_midi_event * dev)149 static inline void reset_encode(struct snd_midi_event *dev)
150 {
151 dev->read = 0;
152 dev->qlen = 0;
153 dev->type = ST_INVALID;
154 }
155
snd_midi_event_reset_encode(struct snd_midi_event * dev)156 void snd_midi_event_reset_encode(struct snd_midi_event *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
snd_midi_event_reset_decode(struct snd_midi_event * dev)165 void snd_midi_event_reset_decode(struct snd_midi_event *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(struct snd_midi_event *dev)
176 {
177 snd_midi_event_reset_encode(dev);
178 snd_midi_event_reset_decode(dev);
179 }
180 #endif /* 0 */
181
snd_midi_event_no_status(struct snd_midi_event * dev,int on)182 void snd_midi_event_no_status(struct snd_midi_event *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(struct snd_midi_event *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 */
snd_midi_event_encode(struct snd_midi_event * dev,unsigned char * buf,long count,struct snd_seq_event * ev)216 long snd_midi_event_encode(struct snd_midi_event *dev, unsigned char *buf, long count,
217 struct snd_seq_event *ev)
218 {
219 long result = 0;
220 int rc;
221
222 ev->type = SNDRV_SEQ_EVENT_NONE;
223
224 while (count-- > 0) {
225 rc = snd_midi_event_encode_byte(dev, *buf++, ev);
226 result++;
227 if (rc < 0)
228 return rc;
229 else if (rc > 0)
230 return result;
231 }
232
233 return result;
234 }
235
236 /*
237 * read one byte and encode to sequencer event:
238 * return 1 if MIDI bytes are encoded to an event
239 * 0 data is not finished
240 * negative for error
241 */
snd_midi_event_encode_byte(struct snd_midi_event * dev,int c,struct snd_seq_event * ev)242 int snd_midi_event_encode_byte(struct snd_midi_event *dev, int c,
243 struct snd_seq_event *ev)
244 {
245 int rc = 0;
246 unsigned long flags;
247
248 c &= 0xff;
249
250 if (c >= MIDI_CMD_COMMON_CLOCK) {
251 /* real-time event */
252 ev->type = status_event[ST_SPECIAL + c - 0xf0].event;
253 ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
254 ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
255 return ev->type != SNDRV_SEQ_EVENT_NONE;
256 }
257
258 spin_lock_irqsave(&dev->lock, flags);
259 if ((c & 0x80) &&
260 (c != MIDI_CMD_COMMON_SYSEX_END || dev->type != ST_SYSEX)) {
261 /* new command */
262 dev->buf[0] = c;
263 if ((c & 0xf0) == 0xf0) /* system messages */
264 dev->type = (c & 0x0f) + ST_SPECIAL;
265 else
266 dev->type = (c >> 4) & 0x07;
267 dev->read = 1;
268 dev->qlen = status_event[dev->type].qlen;
269 } else {
270 if (dev->qlen > 0) {
271 /* rest of command */
272 dev->buf[dev->read++] = c;
273 if (dev->type != ST_SYSEX)
274 dev->qlen--;
275 } else {
276 /* running status */
277 dev->buf[1] = c;
278 dev->qlen = status_event[dev->type].qlen - 1;
279 dev->read = 2;
280 }
281 }
282 if (dev->qlen == 0) {
283 ev->type = status_event[dev->type].event;
284 ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
285 ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
286 if (status_event[dev->type].encode) /* set data values */
287 status_event[dev->type].encode(dev, ev);
288 if (dev->type >= ST_SPECIAL)
289 dev->type = ST_INVALID;
290 rc = 1;
291 } else if (dev->type == ST_SYSEX) {
292 if (c == MIDI_CMD_COMMON_SYSEX_END ||
293 dev->read >= dev->bufsize) {
294 ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
295 ev->flags |= SNDRV_SEQ_EVENT_LENGTH_VARIABLE;
296 ev->type = SNDRV_SEQ_EVENT_SYSEX;
297 ev->data.ext.len = dev->read;
298 ev->data.ext.ptr = dev->buf;
299 if (c != MIDI_CMD_COMMON_SYSEX_END)
300 dev->read = 0; /* continue to parse */
301 else
302 reset_encode(dev); /* all parsed */
303 rc = 1;
304 }
305 }
306
307 spin_unlock_irqrestore(&dev->lock, flags);
308 return rc;
309 }
310
311 /* encode note event */
note_event(struct snd_midi_event * dev,struct snd_seq_event * ev)312 static void note_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
313 {
314 ev->data.note.channel = dev->buf[0] & 0x0f;
315 ev->data.note.note = dev->buf[1];
316 ev->data.note.velocity = dev->buf[2];
317 }
318
319 /* encode one parameter controls */
one_param_ctrl_event(struct snd_midi_event * dev,struct snd_seq_event * ev)320 static void one_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
321 {
322 ev->data.control.channel = dev->buf[0] & 0x0f;
323 ev->data.control.value = dev->buf[1];
324 }
325
326 /* encode pitch wheel change */
pitchbend_ctrl_event(struct snd_midi_event * dev,struct snd_seq_event * ev)327 static void pitchbend_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
328 {
329 ev->data.control.channel = dev->buf[0] & 0x0f;
330 ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1] - 8192;
331 }
332
333 /* encode midi control change */
two_param_ctrl_event(struct snd_midi_event * dev,struct snd_seq_event * ev)334 static void two_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
335 {
336 ev->data.control.channel = dev->buf[0] & 0x0f;
337 ev->data.control.param = dev->buf[1];
338 ev->data.control.value = dev->buf[2];
339 }
340
341 /* encode one parameter value*/
one_param_event(struct snd_midi_event * dev,struct snd_seq_event * ev)342 static void one_param_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
343 {
344 ev->data.control.value = dev->buf[1];
345 }
346
347 /* encode song position */
songpos_event(struct snd_midi_event * dev,struct snd_seq_event * ev)348 static void songpos_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
349 {
350 ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1];
351 }
352
353 /*
354 * decode from a sequencer event to midi bytes
355 * return the size of decoded midi events
356 */
snd_midi_event_decode(struct snd_midi_event * dev,unsigned char * buf,long count,struct snd_seq_event * ev)357 long snd_midi_event_decode(struct snd_midi_event *dev, unsigned char *buf, long count,
358 struct snd_seq_event *ev)
359 {
360 unsigned int cmd, type;
361
362 if (ev->type == SNDRV_SEQ_EVENT_NONE)
363 return -ENOENT;
364
365 for (type = 0; type < ARRAY_SIZE(status_event); type++) {
366 if (ev->type == status_event[type].event)
367 goto __found;
368 }
369 for (type = 0; type < ARRAY_SIZE(extra_event); type++) {
370 if (ev->type == extra_event[type].event)
371 return extra_event[type].decode(dev, buf, count, ev);
372 }
373 return -ENOENT;
374
375 __found:
376 if (type >= ST_SPECIAL)
377 cmd = 0xf0 + (type - ST_SPECIAL);
378 else
379 /* data.note.channel and data.control.channel is identical */
380 cmd = 0x80 | (type << 4) | (ev->data.note.channel & 0x0f);
381
382
383 if (cmd == MIDI_CMD_COMMON_SYSEX) {
384 snd_midi_event_reset_decode(dev);
385 return snd_seq_expand_var_event(ev, count, buf, 1, 0);
386 } else {
387 int qlen;
388 unsigned char xbuf[4];
389 unsigned long flags;
390
391 spin_lock_irqsave(&dev->lock, flags);
392 if ((cmd & 0xf0) == 0xf0 || dev->lastcmd != cmd || dev->nostat) {
393 dev->lastcmd = cmd;
394 spin_unlock_irqrestore(&dev->lock, flags);
395 xbuf[0] = cmd;
396 if (status_event[type].decode)
397 status_event[type].decode(ev, xbuf + 1);
398 qlen = status_event[type].qlen + 1;
399 } else {
400 spin_unlock_irqrestore(&dev->lock, flags);
401 if (status_event[type].decode)
402 status_event[type].decode(ev, xbuf + 0);
403 qlen = status_event[type].qlen;
404 }
405 if (count < qlen)
406 return -ENOMEM;
407 memcpy(buf, xbuf, qlen);
408 return qlen;
409 }
410 }
411
412
413 /* decode note event */
note_decode(struct snd_seq_event * ev,unsigned char * buf)414 static void note_decode(struct snd_seq_event *ev, unsigned char *buf)
415 {
416 buf[0] = ev->data.note.note & 0x7f;
417 buf[1] = ev->data.note.velocity & 0x7f;
418 }
419
420 /* decode one parameter controls */
one_param_decode(struct snd_seq_event * ev,unsigned char * buf)421 static void one_param_decode(struct snd_seq_event *ev, unsigned char *buf)
422 {
423 buf[0] = ev->data.control.value & 0x7f;
424 }
425
426 /* decode pitch wheel change */
pitchbend_decode(struct snd_seq_event * ev,unsigned char * buf)427 static void pitchbend_decode(struct snd_seq_event *ev, unsigned char *buf)
428 {
429 int value = ev->data.control.value + 8192;
430 buf[0] = value & 0x7f;
431 buf[1] = (value >> 7) & 0x7f;
432 }
433
434 /* decode midi control change */
two_param_decode(struct snd_seq_event * ev,unsigned char * buf)435 static void two_param_decode(struct snd_seq_event *ev, unsigned char *buf)
436 {
437 buf[0] = ev->data.control.param & 0x7f;
438 buf[1] = ev->data.control.value & 0x7f;
439 }
440
441 /* decode song position */
songpos_decode(struct snd_seq_event * ev,unsigned char * buf)442 static void songpos_decode(struct snd_seq_event *ev, unsigned char *buf)
443 {
444 buf[0] = ev->data.control.value & 0x7f;
445 buf[1] = (ev->data.control.value >> 7) & 0x7f;
446 }
447
448 /* decode 14bit control */
extra_decode_ctrl14(struct snd_midi_event * dev,unsigned char * buf,int count,struct snd_seq_event * ev)449 static int extra_decode_ctrl14(struct snd_midi_event *dev, unsigned char *buf,
450 int count, struct snd_seq_event *ev)
451 {
452 unsigned char cmd;
453 int idx = 0;
454
455 cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);
456 if (ev->data.control.param < 0x20) {
457 if (count < 4)
458 return -ENOMEM;
459 if (dev->nostat && count < 6)
460 return -ENOMEM;
461 if (cmd != dev->lastcmd || dev->nostat) {
462 if (count < 5)
463 return -ENOMEM;
464 buf[idx++] = dev->lastcmd = cmd;
465 }
466 buf[idx++] = ev->data.control.param;
467 buf[idx++] = (ev->data.control.value >> 7) & 0x7f;
468 if (dev->nostat)
469 buf[idx++] = cmd;
470 buf[idx++] = ev->data.control.param + 0x20;
471 buf[idx++] = ev->data.control.value & 0x7f;
472 } else {
473 if (count < 2)
474 return -ENOMEM;
475 if (cmd != dev->lastcmd || dev->nostat) {
476 if (count < 3)
477 return -ENOMEM;
478 buf[idx++] = dev->lastcmd = cmd;
479 }
480 buf[idx++] = ev->data.control.param & 0x7f;
481 buf[idx++] = ev->data.control.value & 0x7f;
482 }
483 return idx;
484 }
485
486 /* decode reg/nonreg param */
extra_decode_xrpn(struct snd_midi_event * dev,unsigned char * buf,int count,struct snd_seq_event * ev)487 static int extra_decode_xrpn(struct snd_midi_event *dev, unsigned char *buf,
488 int count, struct snd_seq_event *ev)
489 {
490 unsigned char cmd;
491 char *cbytes;
492 static char cbytes_nrpn[4] = { MIDI_CTL_NONREG_PARM_NUM_MSB,
493 MIDI_CTL_NONREG_PARM_NUM_LSB,
494 MIDI_CTL_MSB_DATA_ENTRY,
495 MIDI_CTL_LSB_DATA_ENTRY };
496 static char cbytes_rpn[4] = { MIDI_CTL_REGIST_PARM_NUM_MSB,
497 MIDI_CTL_REGIST_PARM_NUM_LSB,
498 MIDI_CTL_MSB_DATA_ENTRY,
499 MIDI_CTL_LSB_DATA_ENTRY };
500 unsigned char bytes[4];
501 int idx = 0, i;
502
503 if (count < 8)
504 return -ENOMEM;
505 if (dev->nostat && count < 12)
506 return -ENOMEM;
507 cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);
508 bytes[0] = (ev->data.control.param & 0x3f80) >> 7;
509 bytes[1] = ev->data.control.param & 0x007f;
510 bytes[2] = (ev->data.control.value & 0x3f80) >> 7;
511 bytes[3] = ev->data.control.value & 0x007f;
512 if (cmd != dev->lastcmd && !dev->nostat) {
513 if (count < 9)
514 return -ENOMEM;
515 buf[idx++] = dev->lastcmd = cmd;
516 }
517 cbytes = ev->type == SNDRV_SEQ_EVENT_NONREGPARAM ? cbytes_nrpn : cbytes_rpn;
518 for (i = 0; i < 4; i++) {
519 if (dev->nostat)
520 buf[idx++] = dev->lastcmd = cmd;
521 buf[idx++] = cbytes[i];
522 buf[idx++] = bytes[i];
523 }
524 return idx;
525 }
526
527 /*
528 * exports
529 */
530
531 EXPORT_SYMBOL(snd_midi_event_new);
532 EXPORT_SYMBOL(snd_midi_event_free);
533 EXPORT_SYMBOL(snd_midi_event_reset_encode);
534 EXPORT_SYMBOL(snd_midi_event_reset_decode);
535 EXPORT_SYMBOL(snd_midi_event_no_status);
536 EXPORT_SYMBOL(snd_midi_event_encode);
537 EXPORT_SYMBOL(snd_midi_event_encode_byte);
538 EXPORT_SYMBOL(snd_midi_event_decode);
539
alsa_seq_midi_event_init(void)540 static int __init alsa_seq_midi_event_init(void)
541 {
542 return 0;
543 }
544
alsa_seq_midi_event_exit(void)545 static void __exit alsa_seq_midi_event_exit(void)
546 {
547 }
548
549 module_init(alsa_seq_midi_event_init)
550 module_exit(alsa_seq_midi_event_exit)
551