summaryrefslogtreecommitdiffstats
path: root/core.c
blob: cdc75568ca3cbac99a2445e18039845a1ae4e651 (plain)
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
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
// SPDX-License-Identifier: GPL-2.0
/*
 * ALSA Virtual Soundcard
 *
 * core.c - Implementation of core module for virtual ALSA card
 *
 * Copyright (C) 2010-2018 Fiberdyne Systems Pty Ltd
 */

#include <linux/module.h>
#include <linux/string.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <avirt/core.h>

#include "core_internal.h"

MODULE_AUTHOR("JOSHANNE <james.oshannessy@fiberdyne.com.au>");
MODULE_AUTHOR("MFARRUGI <mark.farrugia@fiberdyne.com.au>");
MODULE_DESCRIPTION("A configurable virtual soundcard");
MODULE_LICENSE("GPL v2");

#define D_LOGNAME "core"

#define D_INFOK(fmt, args...) DINFO(D_LOGNAME, fmt, ##args)
#define D_PRINTK(fmt, args...) DDEBUG(D_LOGNAME, fmt, ##args)
#define D_ERRORK(fmt, args...) DERROR(D_LOGNAME, fmt, ##args)

#define SND_AVIRTUAL_DRIVER "snd_avirt"

extern struct snd_pcm_ops pcm_ops;

static struct avirt_core core = {
	.stream_count = 0,
	.streams_sealed = false,
};

struct avirt_coreinfo coreinfo = {
	.version = {0, 0, 1},
};

static LIST_HEAD(audiopath_list);

struct avirt_audiopath_obj {
	struct kobject kobj;
	struct list_head list;
	struct avirt_audiopath *path;
};

static struct kset *avirt_audiopath_kset;
static struct kobject *kobj;

#define to_audiopath_obj(d) container_of(d, struct avirt_audiopath_obj, kobj)
#define to_audiopath_attr(a)                                                   \
	container_of(a, struct avirt_audiopath_attribute, attr)

/**
 * struct avirt_audiopath_attribute - access the attributes of Audio Path
 * @attr: attributes of an Audio Path
 * @show: pointer to the show function
 * @store: pointer to the store function
 */
struct avirt_audiopath_attribute {
	struct attribute attr;
	ssize_t (*show)(struct avirt_audiopath_obj *d,
			struct avirt_audiopath_attribute *attr, char *buf);
	ssize_t (*store)(struct avirt_audiopath_obj *d,
			 struct avirt_audiopath_attribute *attr,
			 const char *buf, size_t count);
};

/**
 * audiopath_attr_show - show function of an Audio Path
 * @kobj: pointer to kobject
 * @attr: pointer to attribute struct
 * @buf: buffer
 */
static ssize_t audiopath_attr_show(struct kobject *kobj, struct attribute *attr,
				   char *buf)
{
	struct avirt_audiopath_attribute *audiopath_attr;
	struct avirt_audiopath_obj *audiopath_obj;

	audiopath_attr = to_audiopath_attr(attr);
	audiopath_obj = to_audiopath_obj(kobj);

	if (!audiopath_attr->show)
		return -EIO;

	return audiopath_attr->show(audiopath_obj, audiopath_attr, buf);
}

/**
 * audiopath_attr_store - attribute store function of Audio Path object
 * @kobj: pointer to kobject
 * @attr: pointer to attribute struct
 * @buf: buffer
 * @len: length of buffer
 */
static ssize_t audiopath_attr_store(struct kobject *kobj,
				    struct attribute *attr, const char *buf,
				    size_t len)
{
	struct avirt_audiopath_attribute *audiopath_attr;
	struct avirt_audiopath_obj *audiopath_obj;

	audiopath_attr = to_audiopath_attr(attr);
	audiopath_obj = to_audiopath_obj(kobj);

	if (!audiopath_attr->store)
		return -EIO;
	return audiopath_attr->store(audiopath_obj, audiopath_attr, buf, len);
}

static const struct sysfs_ops avirt_audiopath_sysfs_ops = {
	.show = audiopath_attr_show,
	.store = audiopath_attr_store,
};

/**
 * avirt_audiopath_release - Audio Path release function
 * @kobj: pointer to Audio Paths's kobject
 */
static void avirt_audiopath_release(struct kobject *kobj)
{
	struct avirt_audiopath_obj *audiopath_obj = to_audiopath_obj(kobj);

	kfree(audiopath_obj);
}

static ssize_t audiopath_name_show(struct avirt_audiopath_obj *audiopath_obj,
				   struct avirt_audiopath_attribute *attr,
				   char *buf)
{
	return sprintf(buf, "%s\n", audiopath_obj->path->name);
}

static ssize_t audiopath_version_show(struct avirt_audiopath_obj *audiopath_obj,
				      struct avirt_audiopath_attribute *attr,
				      char *buf)
{
	struct avirt_audiopath *audiopath = audiopath_obj->path;

	return sprintf(buf, "%d.%d.%d\n", audiopath->version[0],
		       audiopath->version[1], audiopath->version[2]);
}

static struct avirt_audiopath_attribute avirt_audiopath_attrs[] = {
	__ATTR_RO(audiopath_name),
	__ATTR_RO(audiopath_version),
};

static struct attribute *avirt_audiopath_def_attrs[] = {
	&avirt_audiopath_attrs[0].attr,
	&avirt_audiopath_attrs[1].attr,
	NULL,
};

static struct kobj_type avirt_audiopath_ktype = {
	.sysfs_ops = &avirt_audiopath_sysfs_ops,
	.release = avirt_audiopath_release,
	.default_attrs = avirt_audiopath_def_attrs,
};

/**
 * create_avirt_audiopath_obj - creates an Audio Path object
 * @uid: Unique ID of the Audio Path
 *
 * This creates an Audio Path object and assigns the kset and registers
 * it with sysfs.
 * @return: Pointer to the Audio Path object or NULL if it failed.
 */
static struct avirt_audiopath_obj *create_avirt_audiopath_obj(const char *uid)
{
	struct avirt_audiopath_obj *avirt_audiopath;
	int retval;

	avirt_audiopath = kzalloc(sizeof(*avirt_audiopath), GFP_KERNEL);
	if (!avirt_audiopath)
		return NULL;
	avirt_audiopath->kobj.kset = avirt_audiopath_kset;
	retval = kobject_init_and_add(&avirt_audiopath->kobj,
				      &avirt_audiopath_ktype, kobj, "%s", uid);
	if (retval) {
		kobject_put(&avirt_audiopath->kobj);
		return NULL;
	}
	kobject_uevent(&avirt_audiopath->kobj, KOBJ_ADD);
	return avirt_audiopath;
}

/**
 * destroy_avirt_audiopath_obj - destroys an Audio Path object
 * @name: the Audio Path object
 */
static void destroy_avirt_audiopath_obj(struct avirt_audiopath_obj *p)
{
	kobject_put(&p->kobj);
}

/**
 * avirt_audiopath_get - retrieves the Audio Path by its UID
 * @uid: Unique ID for the Audio Path
 * @return: Corresponding Audio Path
 */
struct avirt_audiopath *avirt_audiopath_get(const char *uid)
{
	struct avirt_audiopath_obj *ap_obj;

	list_for_each_entry(ap_obj, &audiopath_list, list)
	{
		// pr_info("get_ap %s\n", ap_obj->path->uid);
		if (!strcmp(ap_obj->path->uid, uid))
			return ap_obj->path;
	}

	return NULL;
}

/**
 * avirt_audiopath_register - register Audio Path with ALSA virtual driver
 * @audiopath: Audio Path to be registered
 * @core: ALSA virtual driver core info
 * @return: 0 on success or error code otherwise
 */
int avirt_audiopath_register(struct avirt_audiopath *audiopath,
			     struct avirt_coreinfo **info)
{
	struct avirt_audiopath_obj *audiopath_obj;

	if (!audiopath) {
		D_ERRORK("Audio Path is NULL!");
		return -EINVAL;
	}

	audiopath_obj = create_avirt_audiopath_obj(audiopath->uid);
	if (!audiopath_obj) {
		D_INFOK("Failed to alloc driver object");
		return -ENOMEM;
	}
	audiopath_obj->path = audiopath;

	audiopath->context = audiopath_obj;
	D_INFOK("Registered new Audio Path: %s", audiopath->name);

	list_add_tail(&audiopath_obj->list, &audiopath_list);

	// If we have already sealed the streams, configure this AP
	if (core.streams_sealed)
		audiopath->configure(core.card, core.stream_group,
				     core.stream_count);

	*info = &coreinfo;

	return 0;
}
EXPORT_SYMBOL_GPL(avirt_audiopath_register);

/**
 * avirt_audiopath_deregister - deregister Audio Path with ALSA virtual driver
 * @audiopath: Audio Path to be deregistered
 * @return: 0 on success or error code otherwise
 */
int avirt_audiopath_deregister(struct avirt_audiopath *audiopath)
{
	struct avirt_audiopath_obj *audiopath_obj;

	// Check if audio path is registered
	if (!audiopath) {
		D_ERRORK("Bad Audio Path Driver");
		return -EINVAL;
	}

	audiopath_obj = audiopath->context;
	if (!audiopath_obj) {
		D_INFOK("driver not registered");
		return -EINVAL;
	}

	list_del(&audiopath_obj->list);
	destroy_avirt_audiopath_obj(audiopath_obj);
	D_INFOK("Deregistered Audio Path %s", audiopath->uid);

	return 0;
}
EXPORT_SYMBOL_GPL(avirt_audiopath_deregister);

/**
 * avirt_stream_count - get the stream count for the given direction
 * @direction: The direction to get the stream count for
 * @return: The stream count
 */
int avirt_stream_count(unsigned int direction)
{
	struct list_head *entry;
	struct config_item *item;
	struct avirt_stream *stream;
	unsigned int count = 0;

	if (direction > 1)
		return -ERANGE;

	list_for_each(entry, &core.stream_group->cg_children)
	{
		item = container_of(entry, struct config_item, ci_entry);
		stream = avirt_stream_from_config_item(item);
		if (!stream)
			return -EFAULT;
		if (stream->direction == direction)
			count++;
	}

	return count;
}
EXPORT_SYMBOL_GPL(avirt_stream_count);

/**
 * __avirt_stream_create - Create audio stream, including it's ALSA PCM device
 * @name: The name designated to the audio stream
 * @direction: The PCM direction (SNDRV_PCM_STREAM_PLAYBACK or
 *             SNDRV_PCM_STREAM_CAPTURE)
 * @return: The newly created audio stream if successful, or an error pointer
 */
struct avirt_stream *__avirt_stream_create(const char *name, int direction)
{
	struct snd_pcm *pcm;
	struct avirt_stream *stream;
	int err;

	stream = kzalloc(sizeof(*stream), GFP_KERNEL);
	if (!stream)
		return ERR_PTR(-ENOMEM);

	strcpy(stream->name, name);
	strcpy(stream->map, "ap_fddsp");
	stream->channels = 0;
	stream->direction = direction;
	stream->device = core.stream_count++;

	err = snd_pcm_new(core.card, name, stream->device, !direction,
			  direction, &pcm);
	if (err < 0)
		return ERR_PTR(err);

	// TD MF: IMPORTANT: NEED TO TEST >8 PCM DEVICES ON A
	// CARD!
	/** Register driver callbacks */
	snd_pcm_set_ops(pcm, direction, &pcm_ops);

	pcm->info_flags = 0;
	strcpy(pcm->name, name);

	pr_info("%s [ARGS] name: %s device:%d\n", __func__, name,
		stream->device);

	// coreinfo.streams[stream_idx] = stream;

	return stream;
}

int __avirt_card_register(void)
{
	int err = 0;
	struct avirt_audiopath_obj *ap_obj;

	if (core.streams_sealed) {
		D_ERRORK("streams are already sealed!");
		return -1;
	}

	list_for_each_entry (ap_obj, &audiopath_list, list) {
		D_INFOK("configure() AP uid: %s", ap_obj->path->uid);
		ap_obj->path->configure(core.card, core.stream_group,
					core.stream_count);
	}

	err = snd_card_register(core.card);
	if (err < 0) {
		D_ERRORK("Sound card registration failed!");
		snd_card_free(core.card);
	}

	core.streams_sealed = true;

	return err;
}

bool __avirt_streams_sealed(void)
{
	return core.streams_sealed;
}

struct avirt_stream *__avirt_stream_find_by_device(unsigned int device)
{
	struct avirt_stream *stream;
	struct config_item *item;
	struct list_head *entry;

	if (device >= core.stream_count) {
		D_ERRORK("Stream device number is larger than stream count");
		return ERR_PTR(-EINVAL);
	}

	list_for_each(entry, &core.stream_group->cg_children)
	{
		item = container_of(entry, struct config_item, ci_entry);
		stream = avirt_stream_from_config_item(item);
		if (!stream)
			return ERR_PTR(-EFAULT);
		if (stream->device == device)
			return stream;
	}

	return NULL;
}

/**
 * core_init - Initialize the kernel module
 */
static int __init core_init(void)
{
	int err;

	D_INFOK("Alsa Virtual Sound Driver avirt-%d.%d.%d", coreinfo.version[0],
		coreinfo.version[1], coreinfo.version[2]);

	core.avirt_class = class_create(THIS_MODULE, SND_AVIRTUAL_DRIVER);
	if (IS_ERR(core.avirt_class)) {
		D_ERRORK("No udev support");
		return PTR_ERR(core.avirt_class);
	}

	core.dev = device_create(core.avirt_class, NULL, 0, NULL, "avirtcore");
	if (IS_ERR(core.dev)) {
		err = PTR_ERR(core.dev);
		goto exit_class;
	}

	// Create the card instance
	err = snd_card_new(core.dev, SNDRV_DEFAULT_IDX1, "avirt", THIS_MODULE,
			   0, &core.card);
	if (err < 0) {
		D_ERRORK("Failed to create sound card");
		goto exit_class_container;
	}

	strncpy(core.card->driver, "avirt-alsa-dev", 16);
	strncpy(core.card->shortname, "avirt", 32);
	strncpy(core.card->longname, "A virtual sound card driver for ALSA",
		80);

	avirt_audiopath_kset =
		kset_create_and_add("audiopaths", NULL, &core.dev->kobj);
	if (!avirt_audiopath_kset) {
		err = -ENOMEM;
		goto exit_snd_card;
	}

	err = __avirt_configfs_init(&core);
	if (err < 0)
		goto exit_snd_card;

	return 0;

exit_snd_card:
	snd_card_free(core.card);
exit_class_container:
	device_destroy(core.avirt_class, 0);
exit_class:
	class_destroy(core.avirt_class);

	return err;
}

/**
 * core_exit - Destroy the kernel module
 */
static void __exit core_exit(void)
{
	__avirt_configfs_exit(&core);

	kset_unregister(avirt_audiopath_kset);
	snd_card_free(core.card);
	device_destroy(core.avirt_class, 0);
	class_destroy(core.avirt_class);
}

module_init(core_init);
module_exit(core_exit);