xref: /linux/sound/core/seq/oss/seq_oss_synth.c (revision 4f5d3da619fdc78c1de2765e2e47a44ee9aba98d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * OSS compatible sequencer driver
4  *
5  * synth device handlers
6  *
7  * Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>
8  */
9 
10 #include "seq_oss_synth.h"
11 #include "seq_oss_midi.h"
12 #include "../seq_lock.h"
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/nospec.h>
17 
18 /*
19  * constants
20  */
21 #define SNDRV_SEQ_OSS_MAX_SYNTH_NAME	30
22 #define MAX_SYSEX_BUFLEN		128
23 
24 
25 /*
26  * definition of synth info records
27  */
28 
29 /* sysex buffer */
30 struct seq_oss_synth_sysex {
31 	int len;
32 	int skip;
33 	unsigned char buf[MAX_SYSEX_BUFLEN];
34 };
35 
36 /* synth info */
37 struct seq_oss_synth {
38 	int seq_device;
39 
40 	/* for synth_info */
41 	int synth_type;
42 	int synth_subtype;
43 	int nr_voices;
44 
45 	char name[SNDRV_SEQ_OSS_MAX_SYNTH_NAME];
46 	struct snd_seq_oss_callback oper;
47 
48 	int opened;
49 
50 	void *private_data;
51 	snd_use_lock_t use_lock;
52 };
53 
54 
55 /*
56  * device table
57  */
58 static int max_synth_devs;
59 static struct seq_oss_synth *synth_devs[SNDRV_SEQ_OSS_MAX_SYNTH_DEVS];
60 static struct seq_oss_synth midi_synth_dev = {
61 	.seq_device = -1,
62 	.synth_type = SYNTH_TYPE_MIDI,
63 	.synth_subtype = 0,
64 	.nr_voices = 16,
65 	.name = "MIDI",
66 };
67 
68 static DEFINE_SPINLOCK(register_lock);
69 static DEFINE_MUTEX(sysex_mutex);
70 
71 /*
72  * prototypes
73  */
74 static struct seq_oss_synth *get_synthdev(struct seq_oss_devinfo *dp, int dev);
75 static void reset_channels(struct seq_oss_synthinfo *info);
76 
77 /*
78  * global initialization
79  */
80 void __init
snd_seq_oss_synth_init(void)81 snd_seq_oss_synth_init(void)
82 {
83 	snd_use_lock_init(&midi_synth_dev.use_lock);
84 }
85 
86 /*
87  * registration of the synth device
88  */
89 int
snd_seq_oss_synth_probe(struct device * _dev)90 snd_seq_oss_synth_probe(struct device *_dev)
91 {
92 	struct snd_seq_device *dev = to_seq_dev(_dev);
93 	int i;
94 	struct seq_oss_synth *rec;
95 	struct snd_seq_oss_reg *reg = SNDRV_SEQ_DEVICE_ARGPTR(dev);
96 	unsigned long flags;
97 
98 	rec = kzalloc(sizeof(*rec), GFP_KERNEL);
99 	if (!rec)
100 		return -ENOMEM;
101 	rec->seq_device = -1;
102 	rec->synth_type = reg->type;
103 	rec->synth_subtype = reg->subtype;
104 	rec->nr_voices = reg->nvoices;
105 	rec->oper = reg->oper;
106 	rec->private_data = reg->private_data;
107 	rec->opened = 0;
108 	snd_use_lock_init(&rec->use_lock);
109 
110 	/* copy and truncate the name of synth device */
111 	strscpy(rec->name, dev->name, sizeof(rec->name));
112 
113 	/* registration */
114 	spin_lock_irqsave(&register_lock, flags);
115 	for (i = 0; i < max_synth_devs; i++) {
116 		if (synth_devs[i] == NULL)
117 			break;
118 	}
119 	if (i >= max_synth_devs) {
120 		if (max_synth_devs >= SNDRV_SEQ_OSS_MAX_SYNTH_DEVS) {
121 			spin_unlock_irqrestore(&register_lock, flags);
122 			pr_err("ALSA: seq_oss: no more synth slot\n");
123 			kfree(rec);
124 			return -ENOMEM;
125 		}
126 		max_synth_devs++;
127 	}
128 	rec->seq_device = i;
129 	synth_devs[i] = rec;
130 	spin_unlock_irqrestore(&register_lock, flags);
131 	dev->driver_data = rec;
132 #ifdef SNDRV_OSS_INFO_DEV_SYNTH
133 	if (i < SNDRV_CARDS)
134 		snd_oss_info_register(SNDRV_OSS_INFO_DEV_SYNTH, i, rec->name);
135 #endif
136 	return 0;
137 }
138 
139 
140 int
snd_seq_oss_synth_remove(struct device * _dev)141 snd_seq_oss_synth_remove(struct device *_dev)
142 {
143 	struct snd_seq_device *dev = to_seq_dev(_dev);
144 	int index;
145 	struct seq_oss_synth *rec = dev->driver_data;
146 	unsigned long flags;
147 
148 	spin_lock_irqsave(&register_lock, flags);
149 	for (index = 0; index < max_synth_devs; index++) {
150 		if (synth_devs[index] == rec)
151 			break;
152 	}
153 	if (index >= max_synth_devs) {
154 		spin_unlock_irqrestore(&register_lock, flags);
155 		pr_err("ALSA: seq_oss: can't unregister synth\n");
156 		return -EINVAL;
157 	}
158 	synth_devs[index] = NULL;
159 	if (index == max_synth_devs - 1) {
160 		for (index--; index >= 0; index--) {
161 			if (synth_devs[index])
162 				break;
163 		}
164 		max_synth_devs = index + 1;
165 	}
166 	spin_unlock_irqrestore(&register_lock, flags);
167 #ifdef SNDRV_OSS_INFO_DEV_SYNTH
168 	if (rec->seq_device < SNDRV_CARDS)
169 		snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_SYNTH, rec->seq_device);
170 #endif
171 
172 	snd_use_lock_sync(&rec->use_lock);
173 	kfree(rec);
174 
175 	return 0;
176 }
177 
178 
179 /*
180  */
181 static struct seq_oss_synth *
get_sdev(int dev)182 get_sdev(int dev)
183 {
184 	struct seq_oss_synth *rec;
185 	unsigned long flags;
186 
187 	spin_lock_irqsave(&register_lock, flags);
188 	rec = synth_devs[dev];
189 	if (rec)
190 		snd_use_lock_use(&rec->use_lock);
191 	spin_unlock_irqrestore(&register_lock, flags);
192 	return rec;
193 }
194 
195 
196 /*
197  * set up synth tables
198  */
199 
200 void
snd_seq_oss_synth_setup(struct seq_oss_devinfo * dp)201 snd_seq_oss_synth_setup(struct seq_oss_devinfo *dp)
202 {
203 	int i;
204 	struct seq_oss_synth *rec;
205 	struct seq_oss_synthinfo *info;
206 
207 	dp->max_synthdev = max_synth_devs;
208 	dp->synth_opened = 0;
209 	memset(dp->synths, 0, sizeof(dp->synths));
210 	for (i = 0; i < dp->max_synthdev; i++) {
211 		rec = get_sdev(i);
212 		if (rec == NULL)
213 			continue;
214 		if (rec->oper.open == NULL || rec->oper.close == NULL) {
215 			snd_use_lock_free(&rec->use_lock);
216 			continue;
217 		}
218 		info = &dp->synths[i];
219 		info->arg.app_index = dp->port;
220 		info->arg.file_mode = dp->file_mode;
221 		info->arg.seq_mode = dp->seq_mode;
222 		if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_SYNTH)
223 			info->arg.event_passing = SNDRV_SEQ_OSS_PROCESS_EVENTS;
224 		else
225 			info->arg.event_passing = SNDRV_SEQ_OSS_PASS_EVENTS;
226 		info->opened = 0;
227 		if (!try_module_get(rec->oper.owner)) {
228 			snd_use_lock_free(&rec->use_lock);
229 			continue;
230 		}
231 		if (rec->oper.open(&info->arg, rec->private_data) < 0) {
232 			module_put(rec->oper.owner);
233 			snd_use_lock_free(&rec->use_lock);
234 			continue;
235 		}
236 		info->nr_voices = rec->nr_voices;
237 		if (info->nr_voices > 0) {
238 			info->ch = kcalloc(info->nr_voices, sizeof(struct seq_oss_chinfo), GFP_KERNEL);
239 			if (!info->ch) {
240 				rec->oper.close(&info->arg);
241 				module_put(rec->oper.owner);
242 				snd_use_lock_free(&rec->use_lock);
243 				continue;
244 			}
245 			reset_channels(info);
246 		}
247 		info->opened++;
248 		rec->opened++;
249 		dp->synth_opened++;
250 		snd_use_lock_free(&rec->use_lock);
251 	}
252 }
253 
254 
255 /*
256  * set up synth tables for MIDI emulation - /dev/music mode only
257  */
258 
259 void
snd_seq_oss_synth_setup_midi(struct seq_oss_devinfo * dp)260 snd_seq_oss_synth_setup_midi(struct seq_oss_devinfo *dp)
261 {
262 	int i;
263 
264 	if (dp->max_synthdev >= SNDRV_SEQ_OSS_MAX_SYNTH_DEVS)
265 		return;
266 
267 	for (i = 0; i < dp->max_mididev; i++) {
268 		struct seq_oss_synthinfo *info;
269 		info = &dp->synths[dp->max_synthdev];
270 		if (snd_seq_oss_midi_open(dp, i, dp->file_mode) < 0)
271 			continue;
272 		info->arg.app_index = dp->port;
273 		info->arg.file_mode = dp->file_mode;
274 		info->arg.seq_mode = dp->seq_mode;
275 		info->arg.private_data = info;
276 		info->is_midi = 1;
277 		info->midi_mapped = i;
278 		info->arg.event_passing = SNDRV_SEQ_OSS_PASS_EVENTS;
279 		snd_seq_oss_midi_get_addr(dp, i, &info->arg.addr);
280 		info->opened = 1;
281 		midi_synth_dev.opened++;
282 		dp->max_synthdev++;
283 		if (dp->max_synthdev >= SNDRV_SEQ_OSS_MAX_SYNTH_DEVS)
284 			break;
285 	}
286 }
287 
288 
289 /*
290  * clean up synth tables
291  */
292 
293 void
snd_seq_oss_synth_cleanup(struct seq_oss_devinfo * dp)294 snd_seq_oss_synth_cleanup(struct seq_oss_devinfo *dp)
295 {
296 	int i;
297 	struct seq_oss_synth *rec;
298 	struct seq_oss_synthinfo *info;
299 
300 	if (snd_BUG_ON(dp->max_synthdev > SNDRV_SEQ_OSS_MAX_SYNTH_DEVS))
301 		return;
302 	for (i = 0; i < dp->max_synthdev; i++) {
303 		info = &dp->synths[i];
304 		if (! info->opened)
305 			continue;
306 		if (info->is_midi) {
307 			if (midi_synth_dev.opened > 0) {
308 				snd_seq_oss_midi_close(dp, info->midi_mapped);
309 				midi_synth_dev.opened--;
310 			}
311 		} else {
312 			rec = get_sdev(i);
313 			if (rec == NULL)
314 				continue;
315 			if (rec->opened > 0) {
316 				rec->oper.close(&info->arg);
317 				module_put(rec->oper.owner);
318 				rec->opened = 0;
319 			}
320 			snd_use_lock_free(&rec->use_lock);
321 		}
322 		kfree(info->sysex);
323 		info->sysex = NULL;
324 		kfree(info->ch);
325 		info->ch = NULL;
326 	}
327 	dp->synth_opened = 0;
328 	dp->max_synthdev = 0;
329 }
330 
331 static struct seq_oss_synthinfo *
get_synthinfo_nospec(struct seq_oss_devinfo * dp,int dev)332 get_synthinfo_nospec(struct seq_oss_devinfo *dp, int dev)
333 {
334 	if (dev < 0 || dev >= dp->max_synthdev)
335 		return NULL;
336 	dev = array_index_nospec(dev, SNDRV_SEQ_OSS_MAX_SYNTH_DEVS);
337 	return &dp->synths[dev];
338 }
339 
340 /*
341  * return synth device information pointer
342  */
343 static struct seq_oss_synth *
get_synthdev(struct seq_oss_devinfo * dp,int dev)344 get_synthdev(struct seq_oss_devinfo *dp, int dev)
345 {
346 	struct seq_oss_synth *rec;
347 	struct seq_oss_synthinfo *info = get_synthinfo_nospec(dp, dev);
348 
349 	if (!info)
350 		return NULL;
351 	if (!info->opened)
352 		return NULL;
353 	if (info->is_midi) {
354 		rec = &midi_synth_dev;
355 		snd_use_lock_use(&rec->use_lock);
356 	} else {
357 		rec = get_sdev(dev);
358 		if (!rec)
359 			return NULL;
360 	}
361 	if (! rec->opened) {
362 		snd_use_lock_free(&rec->use_lock);
363 		return NULL;
364 	}
365 	return rec;
366 }
367 
368 
369 /*
370  * reset note and velocity on each channel.
371  */
372 static void
reset_channels(struct seq_oss_synthinfo * info)373 reset_channels(struct seq_oss_synthinfo *info)
374 {
375 	int i;
376 	if (info->ch == NULL || ! info->nr_voices)
377 		return;
378 	for (i = 0; i < info->nr_voices; i++) {
379 		info->ch[i].note = -1;
380 		info->ch[i].vel = 0;
381 	}
382 }
383 
384 
385 /*
386  * reset synth device:
387  * call reset callback.  if no callback is defined, send a heartbeat
388  * event to the corresponding port.
389  */
390 void
snd_seq_oss_synth_reset(struct seq_oss_devinfo * dp,int dev)391 snd_seq_oss_synth_reset(struct seq_oss_devinfo *dp, int dev)
392 {
393 	struct seq_oss_synth *rec;
394 	struct seq_oss_synthinfo *info;
395 
396 	info = get_synthinfo_nospec(dp, dev);
397 	if (!info || !info->opened)
398 		return;
399 	if (info->sysex)
400 		info->sysex->len = 0; /* reset sysex */
401 	reset_channels(info);
402 	if (info->is_midi) {
403 		if (midi_synth_dev.opened <= 0)
404 			return;
405 		snd_seq_oss_midi_reset(dp, info->midi_mapped);
406 		/* reopen the device */
407 		snd_seq_oss_midi_close(dp, dev);
408 		if (snd_seq_oss_midi_open(dp, info->midi_mapped,
409 					  dp->file_mode) < 0) {
410 			midi_synth_dev.opened--;
411 			info->opened = 0;
412 			kfree(info->sysex);
413 			info->sysex = NULL;
414 			kfree(info->ch);
415 			info->ch = NULL;
416 		}
417 		return;
418 	}
419 
420 	rec = get_sdev(dev);
421 	if (rec == NULL)
422 		return;
423 	if (rec->oper.reset) {
424 		rec->oper.reset(&info->arg);
425 	} else {
426 		struct snd_seq_event ev;
427 		memset(&ev, 0, sizeof(ev));
428 		snd_seq_oss_fill_addr(dp, &ev, info->arg.addr.client,
429 				      info->arg.addr.port);
430 		ev.type = SNDRV_SEQ_EVENT_RESET;
431 		snd_seq_oss_dispatch(dp, &ev, 0, 0);
432 	}
433 	snd_use_lock_free(&rec->use_lock);
434 }
435 
436 
437 /*
438  * load a patch record:
439  * call load_patch callback function
440  */
441 int
snd_seq_oss_synth_load_patch(struct seq_oss_devinfo * dp,int dev,int fmt,const char __user * buf,int p,int c)442 snd_seq_oss_synth_load_patch(struct seq_oss_devinfo *dp, int dev, int fmt,
443 			    const char __user *buf, int p, int c)
444 {
445 	struct seq_oss_synth *rec;
446 	struct seq_oss_synthinfo *info;
447 	int rc;
448 
449 	info = get_synthinfo_nospec(dp, dev);
450 	if (!info)
451 		return -ENXIO;
452 
453 	if (info->is_midi)
454 		return 0;
455 	rec = get_synthdev(dp, dev);
456 	if (!rec)
457 		return -ENXIO;
458 
459 	if (rec->oper.load_patch == NULL)
460 		rc = -ENXIO;
461 	else
462 		rc = rec->oper.load_patch(&info->arg, fmt, buf, p, c);
463 	snd_use_lock_free(&rec->use_lock);
464 	return rc;
465 }
466 
467 /*
468  * check if the device is valid synth device and return the synth info
469  */
470 struct seq_oss_synthinfo *
snd_seq_oss_synth_info(struct seq_oss_devinfo * dp,int dev)471 snd_seq_oss_synth_info(struct seq_oss_devinfo *dp, int dev)
472 {
473 	struct seq_oss_synth *rec;
474 
475 	rec = get_synthdev(dp, dev);
476 	if (rec) {
477 		snd_use_lock_free(&rec->use_lock);
478 		return get_synthinfo_nospec(dp, dev);
479 	}
480 	return NULL;
481 }
482 
483 
484 /*
485  * receive OSS 6 byte sysex packet:
486  * the full sysex message will be sent if it reaches to the end of data
487  * (0xff).
488  */
489 int
snd_seq_oss_synth_sysex(struct seq_oss_devinfo * dp,int dev,unsigned char * buf,struct snd_seq_event * ev)490 snd_seq_oss_synth_sysex(struct seq_oss_devinfo *dp, int dev, unsigned char *buf, struct snd_seq_event *ev)
491 {
492 	int i, send;
493 	unsigned char *dest;
494 	struct seq_oss_synth_sysex *sysex;
495 	struct seq_oss_synthinfo *info;
496 
497 	info = snd_seq_oss_synth_info(dp, dev);
498 	if (!info)
499 		return -ENXIO;
500 
501 	guard(mutex)(&sysex_mutex);
502 	sysex = info->sysex;
503 	if (sysex == NULL) {
504 		sysex = kzalloc(sizeof(*sysex), GFP_KERNEL);
505 		if (sysex == NULL)
506 			return -ENOMEM;
507 		info->sysex = sysex;
508 	}
509 
510 	send = 0;
511 	dest = sysex->buf + sysex->len;
512 	/* copy 6 byte packet to the buffer */
513 	for (i = 0; i < 6; i++) {
514 		if (buf[i] == 0xff) {
515 			send = 1;
516 			break;
517 		}
518 		dest[i] = buf[i];
519 		sysex->len++;
520 		if (sysex->len >= MAX_SYSEX_BUFLEN) {
521 			sysex->len = 0;
522 			sysex->skip = 1;
523 			break;
524 		}
525 	}
526 
527 	if (sysex->len && send) {
528 		if (sysex->skip) {
529 			sysex->skip = 0;
530 			sysex->len = 0;
531 			return -EINVAL; /* skip */
532 		}
533 		/* copy the data to event record and send it */
534 		ev->flags = SNDRV_SEQ_EVENT_LENGTH_VARIABLE;
535 		if (snd_seq_oss_synth_addr(dp, dev, ev))
536 			return -EINVAL;
537 		ev->data.ext.len = sysex->len;
538 		ev->data.ext.ptr = sysex->buf;
539 		sysex->len = 0;
540 		return 0;
541 	}
542 
543 	return -EINVAL; /* skip */
544 }
545 
546 /*
547  * fill the event source/destination addresses
548  */
549 int
snd_seq_oss_synth_addr(struct seq_oss_devinfo * dp,int dev,struct snd_seq_event * ev)550 snd_seq_oss_synth_addr(struct seq_oss_devinfo *dp, int dev, struct snd_seq_event *ev)
551 {
552 	struct seq_oss_synthinfo *info = snd_seq_oss_synth_info(dp, dev);
553 
554 	if (!info)
555 		return -EINVAL;
556 	snd_seq_oss_fill_addr(dp, ev, info->arg.addr.client,
557 			      info->arg.addr.port);
558 	return 0;
559 }
560 
561 
562 /*
563  * OSS compatible ioctl
564  */
565 int
snd_seq_oss_synth_ioctl(struct seq_oss_devinfo * dp,int dev,unsigned int cmd,unsigned long addr)566 snd_seq_oss_synth_ioctl(struct seq_oss_devinfo *dp, int dev, unsigned int cmd, unsigned long addr)
567 {
568 	struct seq_oss_synth *rec;
569 	struct seq_oss_synthinfo *info;
570 	int rc;
571 
572 	info = get_synthinfo_nospec(dp, dev);
573 	if (!info || info->is_midi)
574 		return -ENXIO;
575 	rec = get_synthdev(dp, dev);
576 	if (!rec)
577 		return -ENXIO;
578 	if (rec->oper.ioctl == NULL)
579 		rc = -ENXIO;
580 	else
581 		rc = rec->oper.ioctl(&info->arg, cmd, addr);
582 	snd_use_lock_free(&rec->use_lock);
583 	return rc;
584 }
585 
586 
587 /*
588  * send OSS raw events - SEQ_PRIVATE and SEQ_VOLUME
589  */
590 int
snd_seq_oss_synth_raw_event(struct seq_oss_devinfo * dp,int dev,unsigned char * data,struct snd_seq_event * ev)591 snd_seq_oss_synth_raw_event(struct seq_oss_devinfo *dp, int dev, unsigned char *data, struct snd_seq_event *ev)
592 {
593 	struct seq_oss_synthinfo *info;
594 
595 	info = snd_seq_oss_synth_info(dp, dev);
596 	if (!info || info->is_midi)
597 		return -ENXIO;
598 	ev->type = SNDRV_SEQ_EVENT_OSS;
599 	memcpy(ev->data.raw8.d, data, 8);
600 	return snd_seq_oss_synth_addr(dp, dev, ev);
601 }
602 
603 
604 /*
605  * create OSS compatible synth_info record
606  */
607 int
snd_seq_oss_synth_make_info(struct seq_oss_devinfo * dp,int dev,struct synth_info * inf)608 snd_seq_oss_synth_make_info(struct seq_oss_devinfo *dp, int dev, struct synth_info *inf)
609 {
610 	struct seq_oss_synth *rec;
611 	struct seq_oss_synthinfo *info = get_synthinfo_nospec(dp, dev);
612 
613 	if (!info)
614 		return -ENXIO;
615 
616 	if (info->is_midi) {
617 		struct midi_info minf;
618 		if (snd_seq_oss_midi_make_info(dp, info->midi_mapped, &minf))
619 			return -ENXIO;
620 		inf->synth_type = SYNTH_TYPE_MIDI;
621 		inf->synth_subtype = 0;
622 		inf->nr_voices = 16;
623 		inf->device = dev;
624 		strscpy(inf->name, minf.name, sizeof(inf->name));
625 	} else {
626 		rec = get_synthdev(dp, dev);
627 		if (!rec)
628 			return -ENXIO;
629 		inf->synth_type = rec->synth_type;
630 		inf->synth_subtype = rec->synth_subtype;
631 		inf->nr_voices = rec->nr_voices;
632 		inf->device = dev;
633 		strscpy(inf->name, rec->name, sizeof(inf->name));
634 		snd_use_lock_free(&rec->use_lock);
635 	}
636 	return 0;
637 }
638 
639 
640 #ifdef CONFIG_SND_PROC_FS
641 /*
642  * proc interface
643  */
644 void
snd_seq_oss_synth_info_read(struct snd_info_buffer * buf)645 snd_seq_oss_synth_info_read(struct snd_info_buffer *buf)
646 {
647 	int i;
648 	struct seq_oss_synth *rec;
649 
650 	snd_iprintf(buf, "\nNumber of synth devices: %d\n", max_synth_devs);
651 	for (i = 0; i < max_synth_devs; i++) {
652 		snd_iprintf(buf, "\nsynth %d: ", i);
653 		rec = get_sdev(i);
654 		if (rec == NULL) {
655 			snd_iprintf(buf, "*empty*\n");
656 			continue;
657 		}
658 		snd_iprintf(buf, "[%s]\n", rec->name);
659 		snd_iprintf(buf, "  type 0x%x : subtype 0x%x : voices %d\n",
660 			    rec->synth_type, rec->synth_subtype,
661 			    rec->nr_voices);
662 		snd_iprintf(buf, "  capabilities : ioctl %s / load_patch %s\n",
663 			    enabled_str((long)rec->oper.ioctl),
664 			    enabled_str((long)rec->oper.load_patch));
665 		snd_use_lock_free(&rec->use_lock);
666 	}
667 }
668 #endif /* CONFIG_SND_PROC_FS */
669