Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * OSS compatible sequencer driver
 *
 * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
 */

#include "seq_oss_device.h"
#include "seq_oss_synth.h"
#include "seq_oss_midi.h"
#include "seq_oss_event.h"
#include "seq_oss_timer.h"
#include <sound/seq_oss_legacy.h>
#include "seq_oss_readq.h"
#include "seq_oss_writeq.h"
#include <linux/nospec.h>


/*
 * prototypes
 */
static int extended_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev);
static int chn_voice_event(struct seq_oss_devinfo *dp, union evrec *event_rec, struct snd_seq_event *ev);
static int chn_common_event(struct seq_oss_devinfo *dp, union evrec *event_rec, struct snd_seq_event *ev);
static int timing_event(struct seq_oss_devinfo *dp, union evrec *event_rec, struct snd_seq_event *ev);
static int local_event(struct seq_oss_devinfo *dp, union evrec *event_rec, struct snd_seq_event *ev);
static int old_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev);
static int note_on_event(struct seq_oss_devinfo *dp, int dev, int ch, int note, int vel, struct snd_seq_event *ev);
static int note_off_event(struct seq_oss_devinfo *dp, int dev, int ch, int note, int vel, struct snd_seq_event *ev);
static int set_note_event(struct seq_oss_devinfo *dp, int dev, int type, int ch, int note, int vel, struct snd_seq_event *ev);
static int set_control_event(struct seq_oss_devinfo *dp, int dev, int type, int ch, int param, int val, struct snd_seq_event *ev);
static int set_echo_event(struct seq_oss_devinfo *dp, union evrec *rec, struct snd_seq_event *ev);


/*
 * convert an OSS event to ALSA event
 * return 0 : enqueued
 *        non-zero : invalid - ignored
 */

int
snd_seq_oss_process_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
{
	switch (q->s.code) {
	case SEQ_EXTENDED:
		return extended_event(dp, q, ev);

	case EV_CHN_VOICE:
		return chn_voice_event(dp, q, ev);

	case EV_CHN_COMMON:
		return chn_common_event(dp, q, ev);

	case EV_TIMING:
		return timing_event(dp, q, ev);

	case EV_SEQ_LOCAL:
		return local_event(dp, q, ev);

	case EV_SYSEX:
		return snd_seq_oss_synth_sysex(dp, q->x.dev, q->x.buf, ev);

	case SEQ_MIDIPUTC:
		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC)
			return -EINVAL;
		/* put a midi byte */
		if (! is_write_mode(dp->file_mode))
			break;
		if (snd_seq_oss_midi_open(dp, q->s.dev, SNDRV_SEQ_OSS_FILE_WRITE))
			break;
		if (snd_seq_oss_midi_filemode(dp, q->s.dev) & SNDRV_SEQ_OSS_FILE_WRITE)
			return snd_seq_oss_midi_putc(dp, q->s.dev, q->s.parm1, ev);
		break;

	case SEQ_ECHO:
		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC)
			return -EINVAL;
		return set_echo_event(dp, q, ev);

	case SEQ_PRIVATE:
		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC)
			return -EINVAL;
		return snd_seq_oss_synth_raw_event(dp, q->c[1], q->c, ev);

	default:
		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC)
			return -EINVAL;
		return old_event(dp, q, ev);
	}
	return -EINVAL;
}

/* old type events: mode1 only */
static int
old_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
{
	switch (q->s.code) {
	case SEQ_NOTEOFF:
		return note_off_event(dp, 0, q->n.chn, q->n.note, q->n.vel, ev);

	case SEQ_NOTEON:
		return note_on_event(dp, 0, q->n.chn, q->n.note, q->n.vel, ev);

	case SEQ_WAIT:
		/* skip */
		break;

	case SEQ_PGMCHANGE:
		return set_control_event(dp, 0, SNDRV_SEQ_EVENT_PGMCHANGE,
					 q->n.chn, 0, q->n.note, ev);

	case SEQ_SYNCTIMER:
		return snd_seq_oss_timer_reset(dp->timer);
	}

	return -EINVAL;
}

/* 8bytes extended event: mode1 only */
static int
extended_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
{
	int val;

	switch (q->e.cmd) {
	case SEQ_NOTEOFF:
		return note_off_event(dp, q->e.dev, q->e.chn, q->e.p1, q->e.p2, ev);

	case SEQ_NOTEON:
		return note_on_event(dp, q->e.dev, q->e.chn, q->e.p1, q->e.p2, ev);

	case SEQ_PGMCHANGE:
		return set_control_event(dp, q->e.dev, SNDRV_SEQ_EVENT_PGMCHANGE,
					 q->e.chn, 0, q->e.p1, ev);

	case SEQ_AFTERTOUCH:
		return set_control_event(dp, q->e.dev, SNDRV_SEQ_EVENT_CHANPRESS,
					 q->e.chn, 0, q->e.p1, ev);

	case SEQ_BALANCE:
		/* convert -128:127 to 0:127 */
		val = (char)q->e.p1;
		val = (val + 128) / 2;
		return set_control_event(dp, q->e.dev, SNDRV_SEQ_EVENT_CONTROLLER,
					 q->e.chn, CTL_PAN, val, ev);

	case SEQ_CONTROLLER:
		val = ((short)q->e.p3 << 8) | (short)q->e.p2;
		switch (q->e.p1) {
		case CTRL_PITCH_BENDER: /* SEQ1 V2 control */
			/* -0x2000:0x1fff */
			return set_control_event(dp, q->e.dev,
						 SNDRV_SEQ_EVENT_PITCHBEND,
						 q->e.chn, 0, val, ev);
		case CTRL_PITCH_BENDER_RANGE:
			/* conversion: 100/semitone -> 128/semitone */
			return set_control_event(dp, q->e.dev,
						 SNDRV_SEQ_EVENT_REGPARAM,
						 q->e.chn, 0, val*128/100, ev);
		default:
			return set_control_event(dp, q->e.dev,
						  SNDRV_SEQ_EVENT_CONTROL14,
						  q->e.chn, q->e.p1, val, ev);
		}

	case SEQ_VOLMODE:
		return snd_seq_oss_synth_raw_event(dp, q->e.dev, q->c, ev);

	}
	return -EINVAL;
}

/* channel voice events: mode1 and 2 */
static int
chn_voice_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
{
	if (q->v.chn >= 32)
		return -EINVAL;
	switch (q->v.cmd) {
	case MIDI_NOTEON:
		return note_on_event(dp, q->v.dev, q->v.chn, q->v.note, q->v.parm, ev);

	case MIDI_NOTEOFF:
		return note_off_event(dp, q->v.dev, q->v.chn, q->v.note, q->v.parm, ev);

	case MIDI_KEY_PRESSURE:
		return set_note_event(dp, q->v.dev, SNDRV_SEQ_EVENT_KEYPRESS,
				       q->v.chn, q->v.note, q->v.parm, ev);

	}
	return -EINVAL;
}

/* channel common events: mode1 and 2 */
static int
chn_common_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
{
	if (q->l.chn >= 32)
		return -EINVAL;
	switch (q->l.cmd) {
	case MIDI_PGM_CHANGE:
		return set_control_event(dp, q->l.dev, SNDRV_SEQ_EVENT_PGMCHANGE,
					  q->l.chn, 0, q->l.p1, ev);

	case MIDI_CTL_CHANGE:
		return set_control_event(dp, q->l.dev, SNDRV_SEQ_EVENT_CONTROLLER,
					  q->l.chn, q->l.p1, q->l.val, ev);

	case MIDI_PITCH_BEND:
		/* conversion: 0:0x3fff -> -0x2000:0x1fff */
		return set_control_event(dp, q->l.dev, SNDRV_SEQ_EVENT_PITCHBEND,
					  q->l.chn, 0, q->l.val - 8192, ev);
		
	case MIDI_CHN_PRESSURE:
		return set_control_event(dp, q->l.dev, SNDRV_SEQ_EVENT_CHANPRESS,
					  q->l.chn, 0, q->l.val, ev);
	}
	return -EINVAL;
}

/* timer events: mode1 and mode2 */
static int
timing_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
{
	switch (q->t.cmd) {
	case TMR_ECHO:
		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC)
			return set_echo_event(dp, q, ev);
		else {
			union evrec tmp;
			memset(&tmp, 0, sizeof(tmp));
			/* XXX: only for little-endian! */
			tmp.echo = (q->t.time << 8) | SEQ_ECHO;
			return set_echo_event(dp, &tmp, ev);
		} 

	case TMR_STOP:
		if (dp->seq_mode)
			return snd_seq_oss_timer_stop(dp->timer);
		return 0;

	case TMR_CONTINUE:
		if (dp->seq_mode)
			return snd_seq_oss_timer_continue(dp->timer);
		return 0;

	case TMR_TEMPO:
		if (dp->seq_mode)
			return snd_seq_oss_timer_tempo(dp->timer, q->t.time);
		return 0;
	}

	return -EINVAL;
}

/* local events: mode1 and 2 */
static int
local_event(struct seq_oss_devinfo *dp, union evrec *q, struct snd_seq_event *ev)
{
	return -EINVAL;
}

/*
 * process note-on event for OSS synth
 * three different modes are available:
 * - SNDRV_SEQ_OSS_PROCESS_EVENTS  (for one-voice per channel mode)
 *	Accept note 255 as volume change.
 * - SNDRV_SEQ_OSS_PASS_EVENTS
 *	Pass all events to lowlevel driver anyway
 * - SNDRV_SEQ_OSS_PROCESS_KEYPRESS  (mostly for Emu8000)
 *	Use key-pressure if note >= 128
 */
static int
note_on_event(struct seq_oss_devinfo *dp, int dev, int ch, int note, int vel, struct snd_seq_event *ev)
{
	struct seq_oss_synthinfo *info;

	info = snd_seq_oss_synth_info(dp, dev);
	if (!info)
		return -ENXIO;

	switch (info->arg.event_passing) {
	case SNDRV_SEQ_OSS_PROCESS_EVENTS:
		if (! info->ch || ch < 0 || ch >= info->nr_voices) {
			/* pass directly */
			return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEON, ch, note, vel, ev);
		}

		ch = array_index_nospec(ch, info->nr_voices);
		if (note == 255 && info->ch[ch].note >= 0) {
			/* volume control */
			int type;
			//if (! vel)
				/* set volume to zero -- note off */
			//	type = SNDRV_SEQ_EVENT_NOTEOFF;
			//else
				if (info->ch[ch].vel)
				/* sample already started -- volume change */
				type = SNDRV_SEQ_EVENT_KEYPRESS;
			else
				/* sample not started -- start now */
				type = SNDRV_SEQ_EVENT_NOTEON;
			info->ch[ch].vel = vel;
			return set_note_event(dp, dev, type, ch, info->ch[ch].note, vel, ev);
		} else if (note >= 128)
			return -EINVAL; /* invalid */

		if (note != info->ch[ch].note && info->ch[ch].note >= 0)
			/* note changed - note off at beginning */
			set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEOFF, ch, info->ch[ch].note, 0, ev);
		/* set current status */
		info->ch[ch].note = note;
		info->ch[ch].vel = vel;
		if (vel) /* non-zero velocity - start the note now */
			return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEON, ch, note, vel, ev);
		return -EINVAL;
		
	case SNDRV_SEQ_OSS_PASS_EVENTS:
		/* pass the event anyway */
		return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEON, ch, note, vel, ev);

	case SNDRV_SEQ_OSS_PROCESS_KEYPRESS:
		if (note >= 128) /* key pressure: shifted by 128 */
			return set_note_event(dp, dev, SNDRV_SEQ_EVENT_KEYPRESS, ch, note - 128, vel, ev);
		else /* normal note-on event */
			return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEON, ch, note, vel, ev);
	}
	return -EINVAL;
}

/*
 * process note-off event for OSS synth
 */
static int
note_off_event(struct seq_oss_devinfo *dp, int dev, int ch, int note, int vel, struct snd_seq_event *ev)
{
	struct seq_oss_synthinfo *info;

	info = snd_seq_oss_synth_info(dp, dev);
	if (!info)
		return -ENXIO;

	switch (info->arg.event_passing) {
	case SNDRV_SEQ_OSS_PROCESS_EVENTS:
		if (! info->ch || ch < 0 || ch >= info->nr_voices) {
			/* pass directly */
			return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEON, ch, note, vel, ev);
		}

		ch = array_index_nospec(ch, info->nr_voices);
		if (info->ch[ch].note >= 0) {
			note = info->ch[ch].note;
			info->ch[ch].vel = 0;
			info->ch[ch].note = -1;
			return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEOFF, ch, note, vel, ev);
		}
		return -EINVAL; /* invalid */

	case SNDRV_SEQ_OSS_PASS_EVENTS:
	case SNDRV_SEQ_OSS_PROCESS_KEYPRESS:
		/* pass the event anyway */
		return set_note_event(dp, dev, SNDRV_SEQ_EVENT_NOTEOFF, ch, note, vel, ev);

	}
	return -EINVAL;
}

/*
 * create a note event
 */
static int
set_note_event(struct seq_oss_devinfo *dp, int dev, int type, int ch, int note, int vel, struct snd_seq_event *ev)
{
	if (!snd_seq_oss_synth_info(dp, dev))
		return -ENXIO;
	
	ev->type = type;
	snd_seq_oss_synth_addr(dp, dev, ev);
	ev->data.note.channel = ch;
	ev->data.note.note = note;
	ev->data.note.velocity = vel;

	return 0;
}

/*
 * create a control event
 */
static int
set_control_event(struct seq_oss_devinfo *dp, int dev, int type, int ch, int param, int val, struct snd_seq_event *ev)
{
	if (!snd_seq_oss_synth_info(dp, dev))
		return -ENXIO;
	
	ev->type = type;
	snd_seq_oss_synth_addr(dp, dev, ev);
	ev->data.control.channel = ch;
	ev->data.control.param = param;
	ev->data.control.value = val;

	return 0;
}

/*
 * create an echo event
 */
static int
set_echo_event(struct seq_oss_devinfo *dp, union evrec *rec, struct snd_seq_event *ev)
{
	ev->type = SNDRV_SEQ_EVENT_ECHO;
	/* echo back to itself */
	snd_seq_oss_fill_addr(dp, ev, dp->addr.client, dp->addr.port);
	memcpy(&ev->data, rec, LONG_EVENT_SIZE);
	return 0;
}

/*
 * event input callback from ALSA sequencer:
 * the echo event is processed here.
 */
int
snd_seq_oss_event_input(struct snd_seq_event *ev, int direct, void *private_data,
			int atomic, int hop)
{
	struct seq_oss_devinfo *dp = (struct seq_oss_devinfo *)private_data;
	union evrec *rec;

	if (ev->type != SNDRV_SEQ_EVENT_ECHO)
		return snd_seq_oss_midi_input(ev, direct, private_data);

	if (ev->source.client != dp->cseq)
		return 0; /* ignored */

	rec = (union evrec*)&ev->data;
	if (rec->s.code == SEQ_SYNCTIMER) {
		/* sync echo back */
		snd_seq_oss_writeq_wakeup(dp->writeq, rec->t.time);
		
	} else {
		/* echo back event */
		if (dp->readq == NULL)
			return 0;
		snd_seq_oss_readq_put_event(dp->readq, rec);
	}
	return 0;
}