xref: /openbmc/linux/sound/core/seq/seq_midi_event.c (revision 64c70b1c) 
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 /*
45  * prototypes
46  */
47 static void note_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
48 static void one_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
49 static void pitchbend_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
50 static void two_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
51 static void one_param_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
52 static void songpos_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
53 static void note_decode(struct snd_seq_event *ev, unsigned char *buf);
54 static void one_param_decode(struct snd_seq_event *ev, unsigned char *buf);
55 static void pitchbend_decode(struct snd_seq_event *ev, unsigned char *buf);
56 static void two_param_decode(struct snd_seq_event *ev, unsigned char *buf);
57 static void songpos_decode(struct snd_seq_event *ev, unsigned char *buf);
58 
59 /*
60  * event list
61  */
62 static struct status_event_list {
63 	int event;
64 	int qlen;
65 	void (*encode)(struct snd_midi_event *dev, struct snd_seq_event *ev);
66 	void (*decode)(struct snd_seq_event *ev, unsigned char *buf);
67 } status_event[] = {
68 	/* 0x80 - 0xf0 */
69 	{SNDRV_SEQ_EVENT_NOTEOFF,	2, note_event, note_decode},
70 	{SNDRV_SEQ_EVENT_NOTEON,	2, note_event, note_decode},
71 	{SNDRV_SEQ_EVENT_KEYPRESS,	2, note_event, note_decode},
72 	{SNDRV_SEQ_EVENT_CONTROLLER,	2, two_param_ctrl_event, two_param_decode},
73 	{SNDRV_SEQ_EVENT_PGMCHANGE,	1, one_param_ctrl_event, one_param_decode},
74 	{SNDRV_SEQ_EVENT_CHANPRESS,	1, one_param_ctrl_event, one_param_decode},
75 	{SNDRV_SEQ_EVENT_PITCHBEND,	2, pitchbend_ctrl_event, pitchbend_decode},
76 	{SNDRV_SEQ_EVENT_NONE,		0, NULL, NULL}, /* 0xf0 */
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,		0, NULL, NULL}, /* 0xf4 */
83 	{SNDRV_SEQ_EVENT_NONE,		0, NULL, NULL}, /* 0xf5 */
84 	{SNDRV_SEQ_EVENT_TUNE_REQUEST,	0, NULL, NULL},	/* 0xf6 */
85 	{SNDRV_SEQ_EVENT_NONE,		0, NULL, NULL}, /* 0xf7 */
86 	{SNDRV_SEQ_EVENT_CLOCK,		0, NULL, NULL}, /* 0xf8 */
87 	{SNDRV_SEQ_EVENT_NONE,		0, 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, 		0, 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 
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 	spin_lock_init(&dev->lock);
133 	*rdev = dev;
134 	return 0;
135 }
136 
137 void snd_midi_event_free(struct snd_midi_event *dev)
138 {
139 	if (dev != NULL) {
140 		kfree(dev->buf);
141 		kfree(dev);
142 	}
143 }
144 
145 /*
146  * initialize record
147  */
148 static inline void reset_encode(struct snd_midi_event *dev)
149 {
150 	dev->read = 0;
151 	dev->qlen = 0;
152 	dev->type = 0;
153 }
154 
155 void snd_midi_event_reset_encode(struct snd_midi_event *dev)
156 {
157 	unsigned long flags;
158 
159 	spin_lock_irqsave(&dev->lock, flags);
160 	reset_encode(dev);
161 	spin_unlock_irqrestore(&dev->lock, flags);
162 }
163 
164 void snd_midi_event_reset_decode(struct snd_midi_event *dev)
165 {
166 	unsigned long flags;
167 
168 	spin_lock_irqsave(&dev->lock, flags);
169 	dev->lastcmd = 0xff;
170 	spin_unlock_irqrestore(&dev->lock, flags);
171 }
172 
173 #if 0
174 void snd_midi_event_init(struct snd_midi_event *dev)
175 {
176 	snd_midi_event_reset_encode(dev);
177 	snd_midi_event_reset_decode(dev);
178 }
179 #endif  /*  0  */
180 
181 void snd_midi_event_no_status(struct snd_midi_event *dev, int on)
182 {
183 	dev->nostat = on ? 1 : 0;
184 }
185 
186 /*
187  * resize buffer
188  */
189 #if 0
190 int snd_midi_event_resize_buffer(struct snd_midi_event *dev, int bufsize)
191 {
192 	unsigned char *new_buf, *old_buf;
193 	unsigned long flags;
194 
195 	if (bufsize == dev->bufsize)
196 		return 0;
197 	new_buf = kmalloc(bufsize, GFP_KERNEL);
198 	if (new_buf == NULL)
199 		return -ENOMEM;
200 	spin_lock_irqsave(&dev->lock, flags);
201 	old_buf = dev->buf;
202 	dev->buf = new_buf;
203 	dev->bufsize = bufsize;
204 	reset_encode(dev);
205 	spin_unlock_irqrestore(&dev->lock, flags);
206 	kfree(old_buf);
207 	return 0;
208 }
209 #endif  /*  0  */
210 
211 /*
212  *  read bytes and encode to sequencer event if finished
213  *  return the size of encoded bytes
214  */
215 long snd_midi_event_encode(struct snd_midi_event *dev, unsigned char *buf, long count,
216 			   struct snd_seq_event *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(struct snd_midi_event *dev, int c,
242 			       struct snd_seq_event *ev)
243 {
244 	int rc = 0;
245 	unsigned long flags;
246 
247 	c &= 0xff;
248 
249 	if (c >= MIDI_CMD_COMMON_CLOCK) {
250 		/* real-time event */
251 		ev->type = status_event[ST_SPECIAL + c - 0xf0].event;
252 		ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
253 		ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
254 		return 1;
255 	}
256 
257 	spin_lock_irqsave(&dev->lock, flags);
258 	if (dev->qlen > 0) {
259 		/* rest of command */
260 		dev->buf[dev->read++] = c;
261 		if (dev->type != ST_SYSEX)
262 			dev->qlen--;
263 	} else {
264 		/* new command */
265 		dev->read = 1;
266 		if (c & 0x80) {
267 			dev->buf[0] = c;
268 			if ((c & 0xf0) == 0xf0) /* special events */
269 				dev->type = (c & 0x0f) + ST_SPECIAL;
270 			else
271 				dev->type = (c >> 4) & 0x07;
272 			dev->qlen = status_event[dev->type].qlen;
273 		} else {
274 			/* process this byte as argument */
275 			dev->buf[dev->read++] = c;
276 			dev->qlen = status_event[dev->type].qlen - 1;
277 		}
278 	}
279 	if (dev->qlen == 0) {
280 		ev->type = status_event[dev->type].event;
281 		ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
282 		ev->flags |= SNDRV_SEQ_EVENT_LENGTH_FIXED;
283 		if (status_event[dev->type].encode) /* set data values */
284 			status_event[dev->type].encode(dev, ev);
285 		rc = 1;
286 	} else 	if (dev->type == ST_SYSEX) {
287 		if (c == MIDI_CMD_COMMON_SYSEX_END ||
288 		    dev->read >= dev->bufsize) {
289 			ev->flags &= ~SNDRV_SEQ_EVENT_LENGTH_MASK;
290 			ev->flags |= SNDRV_SEQ_EVENT_LENGTH_VARIABLE;
291 			ev->type = SNDRV_SEQ_EVENT_SYSEX;
292 			ev->data.ext.len = dev->read;
293 			ev->data.ext.ptr = dev->buf;
294 			if (c != MIDI_CMD_COMMON_SYSEX_END)
295 				dev->read = 0; /* continue to parse */
296 			else
297 				reset_encode(dev); /* all parsed */
298 			rc = 1;
299 		}
300 	}
301 
302 	spin_unlock_irqrestore(&dev->lock, flags);
303 	return rc;
304 }
305 
306 /* encode note event */
307 static void note_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
308 {
309 	ev->data.note.channel = dev->buf[0] & 0x0f;
310 	ev->data.note.note = dev->buf[1];
311 	ev->data.note.velocity = dev->buf[2];
312 }
313 
314 /* encode one parameter controls */
315 static void one_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
316 {
317 	ev->data.control.channel = dev->buf[0] & 0x0f;
318 	ev->data.control.value = dev->buf[1];
319 }
320 
321 /* encode pitch wheel change */
322 static void pitchbend_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
323 {
324 	ev->data.control.channel = dev->buf[0] & 0x0f;
325 	ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1] - 8192;
326 }
327 
328 /* encode midi control change */
329 static void two_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
330 {
331 	ev->data.control.channel = dev->buf[0] & 0x0f;
332 	ev->data.control.param = dev->buf[1];
333 	ev->data.control.value = dev->buf[2];
334 }
335 
336 /* encode one parameter value*/
337 static void one_param_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
338 {
339 	ev->data.control.value = dev->buf[1];
340 }
341 
342 /* encode song position */
343 static void songpos_event(struct snd_midi_event *dev, struct snd_seq_event *ev)
344 {
345 	ev->data.control.value = (int)dev->buf[2] * 128 + (int)dev->buf[1];
346 }
347 
348 /*
349  * decode from a sequencer event to midi bytes
350  * return the size of decoded midi events
351  */
352 long snd_midi_event_decode(struct snd_midi_event *dev, unsigned char *buf, long count,
353 			   struct snd_seq_event *ev)
354 {
355 	unsigned int cmd, type;
356 
357 	if (ev->type == SNDRV_SEQ_EVENT_NONE)
358 		return -ENOENT;
359 
360 	for (type = 0; type < ARRAY_SIZE(status_event); type++) {
361 		if (ev->type == status_event[type].event)
362 			goto __found;
363 	}
364 	for (type = 0; type < ARRAY_SIZE(extra_event); type++) {
365 		if (ev->type == extra_event[type].event)
366 			return extra_event[type].decode(dev, buf, count, ev);
367 	}
368 	return -ENOENT;
369 
370       __found:
371 	if (type >= ST_SPECIAL)
372 		cmd = 0xf0 + (type - ST_SPECIAL);
373 	else
374 		/* data.note.channel and data.control.channel is identical */
375 		cmd = 0x80 | (type << 4) | (ev->data.note.channel & 0x0f);
376 
377 
378 	if (cmd == MIDI_CMD_COMMON_SYSEX) {
379 		snd_midi_event_reset_decode(dev);
380 		return snd_seq_expand_var_event(ev, count, buf, 1, 0);
381 	} else {
382 		int qlen;
383 		unsigned char xbuf[4];
384 		unsigned long flags;
385 
386 		spin_lock_irqsave(&dev->lock, flags);
387 		if ((cmd & 0xf0) == 0xf0 || dev->lastcmd != cmd || dev->nostat) {
388 			dev->lastcmd = cmd;
389 			spin_unlock_irqrestore(&dev->lock, flags);
390 			xbuf[0] = cmd;
391 			if (status_event[type].decode)
392 				status_event[type].decode(ev, xbuf + 1);
393 			qlen = status_event[type].qlen + 1;
394 		} else {
395 			spin_unlock_irqrestore(&dev->lock, flags);
396 			if (status_event[type].decode)
397 				status_event[type].decode(ev, xbuf + 0);
398 			qlen = status_event[type].qlen;
399 		}
400 		if (count < qlen)
401 			return -ENOMEM;
402 		memcpy(buf, xbuf, qlen);
403 		return qlen;
404 	}
405 }
406 
407 
408 /* decode note event */
409 static void note_decode(struct snd_seq_event *ev, unsigned char *buf)
410 {
411 	buf[0] = ev->data.note.note & 0x7f;
412 	buf[1] = ev->data.note.velocity & 0x7f;
413 }
414 
415 /* decode one parameter controls */
416 static void one_param_decode(struct snd_seq_event *ev, unsigned char *buf)
417 {
418 	buf[0] = ev->data.control.value & 0x7f;
419 }
420 
421 /* decode pitch wheel change */
422 static void pitchbend_decode(struct snd_seq_event *ev, unsigned char *buf)
423 {
424 	int value = ev->data.control.value + 8192;
425 	buf[0] = value & 0x7f;
426 	buf[1] = (value >> 7) & 0x7f;
427 }
428 
429 /* decode midi control change */
430 static void two_param_decode(struct snd_seq_event *ev, unsigned char *buf)
431 {
432 	buf[0] = ev->data.control.param & 0x7f;
433 	buf[1] = ev->data.control.value & 0x7f;
434 }
435 
436 /* decode song position */
437 static void songpos_decode(struct snd_seq_event *ev, unsigned char *buf)
438 {
439 	buf[0] = ev->data.control.value & 0x7f;
440 	buf[1] = (ev->data.control.value >> 7) & 0x7f;
441 }
442 
443 /* decode 14bit control */
444 static int extra_decode_ctrl14(struct snd_midi_event *dev, unsigned char *buf,
445 			       int count, struct snd_seq_event *ev)
446 {
447 	unsigned char cmd;
448 	int idx = 0;
449 
450 	cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);
451 	if (ev->data.control.param < 0x20) {
452 		if (count < 4)
453 			return -ENOMEM;
454 		if (dev->nostat && count < 6)
455 			return -ENOMEM;
456 		if (cmd != dev->lastcmd || dev->nostat) {
457 			if (count < 5)
458 				return -ENOMEM;
459 			buf[idx++] = dev->lastcmd = cmd;
460 		}
461 		buf[idx++] = ev->data.control.param;
462 		buf[idx++] = (ev->data.control.value >> 7) & 0x7f;
463 		if (dev->nostat)
464 			buf[idx++] = cmd;
465 		buf[idx++] = ev->data.control.param + 0x20;
466 		buf[idx++] = ev->data.control.value & 0x7f;
467 	} else {
468 		if (count < 2)
469 			return -ENOMEM;
470 		if (cmd != dev->lastcmd || dev->nostat) {
471 			if (count < 3)
472 				return -ENOMEM;
473 			buf[idx++] = dev->lastcmd = cmd;
474 		}
475 		buf[idx++] = ev->data.control.param & 0x7f;
476 		buf[idx++] = ev->data.control.value & 0x7f;
477 	}
478 	return idx;
479 }
480 
481 /* decode reg/nonreg param */
482 static int extra_decode_xrpn(struct snd_midi_event *dev, unsigned char *buf,
483 			     int count, struct snd_seq_event *ev)
484 {
485 	unsigned char cmd;
486 	char *cbytes;
487 	static char cbytes_nrpn[4] = { MIDI_CTL_NONREG_PARM_NUM_MSB,
488 				       MIDI_CTL_NONREG_PARM_NUM_LSB,
489 				       MIDI_CTL_MSB_DATA_ENTRY,
490 				       MIDI_CTL_LSB_DATA_ENTRY };
491 	static char cbytes_rpn[4] =  { MIDI_CTL_REGIST_PARM_NUM_MSB,
492 				       MIDI_CTL_REGIST_PARM_NUM_LSB,
493 				       MIDI_CTL_MSB_DATA_ENTRY,
494 				       MIDI_CTL_LSB_DATA_ENTRY };
495 	unsigned char bytes[4];
496 	int idx = 0, i;
497 
498 	if (count < 8)
499 		return -ENOMEM;
500 	if (dev->nostat && count < 12)
501 		return -ENOMEM;
502 	cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);
503 	bytes[0] = ev->data.control.param & 0x007f;
504 	bytes[1] = (ev->data.control.param & 0x3f80) >> 7;
505 	bytes[2] = ev->data.control.value & 0x007f;
506 	bytes[3] = (ev->data.control.value & 0x3f80) >> 7;
507 	if (cmd != dev->lastcmd && !dev->nostat) {
508 		if (count < 9)
509 			return -ENOMEM;
510 		buf[idx++] = dev->lastcmd = cmd;
511 	}
512 	cbytes = ev->type == SNDRV_SEQ_EVENT_NONREGPARAM ? cbytes_nrpn : cbytes_rpn;
513 	for (i = 0; i < 4; i++) {
514 		if (dev->nostat)
515 			buf[idx++] = dev->lastcmd = cmd;
516 		buf[idx++] = cbytes[i];
517 		buf[idx++] = bytes[i];
518 	}
519 	return idx;
520 }
521 
522 /*
523  *  exports
524  */
525 
526 EXPORT_SYMBOL(snd_midi_event_new);
527 EXPORT_SYMBOL(snd_midi_event_free);
528 EXPORT_SYMBOL(snd_midi_event_reset_encode);
529 EXPORT_SYMBOL(snd_midi_event_reset_decode);
530 EXPORT_SYMBOL(snd_midi_event_no_status);
531 EXPORT_SYMBOL(snd_midi_event_encode);
532 EXPORT_SYMBOL(snd_midi_event_encode_byte);
533 EXPORT_SYMBOL(snd_midi_event_decode);
534 
535 static int __init alsa_seq_midi_event_init(void)
536 {
537 	return 0;
538 }
539 
540 static void __exit alsa_seq_midi_event_exit(void)
541 {
542 }
543 
544 module_init(alsa_seq_midi_event_init)
545 module_exit(alsa_seq_midi_event_exit)
546