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
31MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>, Jaroslav Kysela <perex@perex.cz>");
32MODULE_DESCRIPTION("MIDI byte <-> sequencer event coder");
33MODULE_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 */
46static void note_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
47static void one_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
48static void pitchbend_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
49static void two_param_ctrl_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
50static void one_param_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
51static void songpos_event(struct snd_midi_event *dev, struct snd_seq_event *ev);
52static void note_decode(struct snd_seq_event *ev, unsigned char *buf);
53static void one_param_decode(struct snd_seq_event *ev, unsigned char *buf);
54static void pitchbend_decode(struct snd_seq_event *ev, unsigned char *buf);
55static void two_param_decode(struct snd_seq_event *ev, unsigned char *buf);
56static void songpos_decode(struct snd_seq_event *ev, unsigned char *buf);
57
58/*
59 * event list
60 */
61static 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
96static int extra_decode_ctrl14(struct snd_midi_event *dev, unsigned char *buf, int len,
97			       struct snd_seq_event *ev);
98static int extra_decode_xrpn(struct snd_midi_event *dev, unsigned char *buf, int count,
99			     struct snd_seq_event *ev);
100
101static 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
115int 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
138void 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 */
149static 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
156void 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
165void 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
175void 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
182void 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
191int 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 */
216long 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 */
242int 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 */
312static 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 */
320static 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 */
327static 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 */
334static 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*/
342static 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 */
348static 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 */
357long 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 */
414static 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 */
421static 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 */
427static 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 */
435static 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 */
442static 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 */
449static 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 */
487static 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
531EXPORT_SYMBOL(snd_midi_event_new);
532EXPORT_SYMBOL(snd_midi_event_free);
533EXPORT_SYMBOL(snd_midi_event_reset_encode);
534EXPORT_SYMBOL(snd_midi_event_reset_decode);
535EXPORT_SYMBOL(snd_midi_event_no_status);
536EXPORT_SYMBOL(snd_midi_event_encode);
537EXPORT_SYMBOL(snd_midi_event_encode_byte);
538EXPORT_SYMBOL(snd_midi_event_decode);
539
540static int __init alsa_seq_midi_event_init(void)
541{
542	return 0;
543}
544
545static void __exit alsa_seq_midi_event_exit(void)
546{
547}
548
549module_init(alsa_seq_midi_event_init)
550module_exit(alsa_seq_midi_event_exit)
551