xref: /linux/drivers/usb/gadget/function/u_audio.c (revision 90d32e92011eaae8e70a9169b4e7acf4ca8f9d3a)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * u_audio.c -- interface to USB gadget "ALSA sound card" utilities
4  *
5  * Copyright (C) 2016
6  * Author: Ruslan Bilovol <ruslan.bilovol@gmail.com>
7  *
8  * Sound card implementation was cut-and-pasted with changes
9  * from f_uac2.c and has:
10  *    Copyright (C) 2011
11  *    Yadwinder Singh (yadi.brar01@gmail.com)
12  *    Jaswinder Singh (jaswinder.singh@linaro.org)
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <sound/core.h>
18 #include <sound/pcm.h>
19 #include <sound/pcm_params.h>
20 #include <sound/control.h>
21 #include <sound/tlv.h>
22 #include <linux/usb/audio.h>
23 
24 #include "u_audio.h"
25 
26 #define BUFF_SIZE_MAX	(PAGE_SIZE * 16)
27 #define PRD_SIZE_MAX	PAGE_SIZE
28 #define MIN_PERIODS	4
29 
30 enum {
31 	UAC_FBACK_CTRL,
32 	UAC_P_PITCH_CTRL,
33 	UAC_MUTE_CTRL,
34 	UAC_VOLUME_CTRL,
35 	UAC_RATE_CTRL,
36 };
37 
38 /* Runtime data params for one stream */
39 struct uac_rtd_params {
40 	struct snd_uac_chip *uac; /* parent chip */
41 	bool ep_enabled; /* if the ep is enabled */
42 
43 	struct snd_pcm_substream *ss;
44 
45 	/* Ring buffer */
46 	ssize_t hw_ptr;
47 
48 	void *rbuf;
49 
50 	unsigned int pitch;	/* Stream pitch ratio to 1000000 */
51 	unsigned int max_psize;	/* MaxPacketSize of endpoint */
52 
53 	struct usb_request **reqs;
54 
55 	struct usb_request *req_fback; /* Feedback endpoint request */
56 	bool fb_ep_enabled; /* if the ep is enabled */
57 
58   /* Volume/Mute controls and their state */
59   int fu_id; /* Feature Unit ID */
60   struct snd_ctl_elem_id snd_kctl_volume_id;
61   struct snd_ctl_elem_id snd_kctl_mute_id;
62   s16 volume_min, volume_max, volume_res;
63   s16 volume;
64   int mute;
65 
66 	struct snd_ctl_elem_id snd_kctl_rate_id; /* read-only current rate */
67 	int srate; /* selected samplerate */
68 	int active; /* playback/capture running */
69 
70   spinlock_t lock; /* lock for control transfers */
71 
72 };
73 
74 struct snd_uac_chip {
75 	struct g_audio *audio_dev;
76 
77 	struct uac_rtd_params p_prm;
78 	struct uac_rtd_params c_prm;
79 
80 	struct snd_card *card;
81 	struct snd_pcm *pcm;
82 
83 	/* pre-calculated values for playback iso completion */
84 	unsigned long long p_residue_mil;
85 	unsigned int p_interval;
86 	unsigned int p_framesize;
87 };
88 
89 static const struct snd_pcm_hardware uac_pcm_hardware = {
90 	.info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER
91 		 | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID
92 		 | SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME,
93 	.rates = SNDRV_PCM_RATE_CONTINUOUS,
94 	.periods_max = BUFF_SIZE_MAX / PRD_SIZE_MAX,
95 	.buffer_bytes_max = BUFF_SIZE_MAX,
96 	.period_bytes_max = PRD_SIZE_MAX,
97 	.periods_min = MIN_PERIODS,
98 };
99 
100 static void u_audio_set_fback_frequency(enum usb_device_speed speed,
101 					struct usb_ep *out_ep,
102 					unsigned long long freq,
103 					unsigned int pitch,
104 					void *buf)
105 {
106 	u32 ff = 0;
107 	const struct usb_endpoint_descriptor *ep_desc;
108 
109 	/*
110 	 * Because the pitch base is 1000000, the final divider here
111 	 * will be 1000 * 1000000 = 1953125 << 9
112 	 *
113 	 * Instead of dealing with big numbers lets fold this 9 left shift
114 	 */
115 
116 	if (speed == USB_SPEED_FULL) {
117 		/*
118 		 * Full-speed feedback endpoints report frequency
119 		 * in samples/frame
120 		 * Format is encoded in Q10.10 left-justified in the 24 bits,
121 		 * so that it has a Q10.14 format.
122 		 *
123 		 * ff = (freq << 14) / 1000
124 		 */
125 		freq <<= 5;
126 	} else {
127 		/*
128 		 * High-speed feedback endpoints report frequency
129 		 * in samples/microframe.
130 		 * Format is encoded in Q12.13 fitted into four bytes so that
131 		 * the binary point is located between the second and the third
132 		 * byte fromat (that is Q16.16)
133 		 *
134 		 * ff = (freq << 16) / 8000
135 		 *
136 		 * Win10 and OSX UAC2 drivers require number of samples per packet
137 		 * in order to honor the feedback value.
138 		 * Linux snd-usb-audio detects the applied bit-shift automatically.
139 		 */
140 		ep_desc = out_ep->desc;
141 		freq <<= 4 + (ep_desc->bInterval - 1);
142 	}
143 
144 	ff = DIV_ROUND_CLOSEST_ULL((freq * pitch), 1953125);
145 
146 	*(__le32 *)buf = cpu_to_le32(ff);
147 }
148 
149 static void u_audio_iso_complete(struct usb_ep *ep, struct usb_request *req)
150 {
151 	unsigned int pending;
152 	unsigned int hw_ptr;
153 	int status = req->status;
154 	struct snd_pcm_substream *substream;
155 	struct snd_pcm_runtime *runtime;
156 	struct uac_rtd_params *prm = req->context;
157 	struct snd_uac_chip *uac = prm->uac;
158 	unsigned int frames, p_pktsize;
159 	unsigned long long pitched_rate_mil, p_pktsize_residue_mil,
160 			residue_frames_mil, div_result;
161 
162 	/* i/f shutting down */
163 	if (!prm->ep_enabled) {
164 		usb_ep_free_request(ep, req);
165 		return;
166 	}
167 
168 	if (req->status == -ESHUTDOWN)
169 		return;
170 
171 	/*
172 	 * We can't really do much about bad xfers.
173 	 * Afterall, the ISOCH xfers could fail legitimately.
174 	 */
175 	if (status)
176 		pr_debug("%s: iso_complete status(%d) %d/%d\n",
177 			__func__, status, req->actual, req->length);
178 
179 	substream = prm->ss;
180 
181 	/* Do nothing if ALSA isn't active */
182 	if (!substream)
183 		goto exit;
184 
185 	snd_pcm_stream_lock(substream);
186 
187 	runtime = substream->runtime;
188 	if (!runtime || !snd_pcm_running(substream)) {
189 		snd_pcm_stream_unlock(substream);
190 		goto exit;
191 	}
192 
193 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
194 		/*
195 		 * For each IN packet, take the quotient of the current data
196 		 * rate and the endpoint's interval as the base packet size.
197 		 * If there is a residue from this division, add it to the
198 		 * residue accumulator.
199 		 */
200 		unsigned long long p_interval_mil = uac->p_interval * 1000000ULL;
201 
202 		pitched_rate_mil = (unsigned long long) prm->srate * prm->pitch;
203 		div_result = pitched_rate_mil;
204 		do_div(div_result, uac->p_interval);
205 		do_div(div_result, 1000000);
206 		frames = (unsigned int) div_result;
207 
208 		pr_debug("p_srate %d, pitch %d, interval_mil %llu, frames %d\n",
209 				prm->srate, prm->pitch, p_interval_mil, frames);
210 
211 		p_pktsize = min_t(unsigned int,
212 					uac->p_framesize * frames,
213 					ep->maxpacket);
214 
215 		if (p_pktsize < ep->maxpacket) {
216 			residue_frames_mil = pitched_rate_mil - frames * p_interval_mil;
217 			p_pktsize_residue_mil = uac->p_framesize * residue_frames_mil;
218 		} else
219 			p_pktsize_residue_mil = 0;
220 
221 		req->length = p_pktsize;
222 		uac->p_residue_mil += p_pktsize_residue_mil;
223 
224 		/*
225 		 * Whenever there are more bytes in the accumulator p_residue_mil than we
226 		 * need to add one more sample frame, increase this packet's
227 		 * size and decrease the accumulator.
228 		 */
229 		div_result = uac->p_residue_mil;
230 		do_div(div_result, uac->p_interval);
231 		do_div(div_result, 1000000);
232 		if ((unsigned int) div_result >= uac->p_framesize) {
233 			req->length += uac->p_framesize;
234 			uac->p_residue_mil -= uac->p_framesize * p_interval_mil;
235 			pr_debug("increased req length to %d\n", req->length);
236 		}
237 		pr_debug("remains uac->p_residue_mil %llu\n", uac->p_residue_mil);
238 
239 		req->actual = req->length;
240 	}
241 
242 	hw_ptr = prm->hw_ptr;
243 
244 	/* Pack USB load in ALSA ring buffer */
245 	pending = runtime->dma_bytes - hw_ptr;
246 
247 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
248 		if (unlikely(pending < req->actual)) {
249 			memcpy(req->buf, runtime->dma_area + hw_ptr, pending);
250 			memcpy(req->buf + pending, runtime->dma_area,
251 			       req->actual - pending);
252 		} else {
253 			memcpy(req->buf, runtime->dma_area + hw_ptr,
254 			       req->actual);
255 		}
256 	} else {
257 		if (unlikely(pending < req->actual)) {
258 			memcpy(runtime->dma_area + hw_ptr, req->buf, pending);
259 			memcpy(runtime->dma_area, req->buf + pending,
260 			       req->actual - pending);
261 		} else {
262 			memcpy(runtime->dma_area + hw_ptr, req->buf,
263 			       req->actual);
264 		}
265 	}
266 
267 	/* update hw_ptr after data is copied to memory */
268 	prm->hw_ptr = (hw_ptr + req->actual) % runtime->dma_bytes;
269 	hw_ptr = prm->hw_ptr;
270 	snd_pcm_stream_unlock(substream);
271 
272 	if ((hw_ptr % snd_pcm_lib_period_bytes(substream)) < req->actual)
273 		snd_pcm_period_elapsed(substream);
274 
275 exit:
276 	if (usb_ep_queue(ep, req, GFP_ATOMIC))
277 		dev_err(uac->card->dev, "%d Error!\n", __LINE__);
278 }
279 
280 static void u_audio_iso_fback_complete(struct usb_ep *ep,
281 				       struct usb_request *req)
282 {
283 	struct uac_rtd_params *prm = req->context;
284 	struct snd_uac_chip *uac = prm->uac;
285 	struct g_audio *audio_dev = uac->audio_dev;
286 	int status = req->status;
287 
288 	/* i/f shutting down */
289 	if (!prm->fb_ep_enabled) {
290 		kfree(req->buf);
291 		usb_ep_free_request(ep, req);
292 		return;
293 	}
294 
295 	if (req->status == -ESHUTDOWN)
296 		return;
297 
298 	/*
299 	 * We can't really do much about bad xfers.
300 	 * Afterall, the ISOCH xfers could fail legitimately.
301 	 */
302 	if (status)
303 		pr_debug("%s: iso_complete status(%d) %d/%d\n",
304 			__func__, status, req->actual, req->length);
305 
306 	u_audio_set_fback_frequency(audio_dev->gadget->speed, audio_dev->out_ep,
307 				    prm->srate, prm->pitch,
308 				    req->buf);
309 
310 	if (usb_ep_queue(ep, req, GFP_ATOMIC))
311 		dev_err(uac->card->dev, "%d Error!\n", __LINE__);
312 }
313 
314 static int uac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
315 {
316 	struct snd_uac_chip *uac = snd_pcm_substream_chip(substream);
317 	struct uac_rtd_params *prm;
318 	struct g_audio *audio_dev;
319 	struct uac_params *params;
320 	int err = 0;
321 
322 	audio_dev = uac->audio_dev;
323 	params = &audio_dev->params;
324 
325 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
326 		prm = &uac->p_prm;
327 	else
328 		prm = &uac->c_prm;
329 
330 	/* Reset */
331 	prm->hw_ptr = 0;
332 
333 	switch (cmd) {
334 	case SNDRV_PCM_TRIGGER_START:
335 	case SNDRV_PCM_TRIGGER_RESUME:
336 		prm->ss = substream;
337 		break;
338 	case SNDRV_PCM_TRIGGER_STOP:
339 	case SNDRV_PCM_TRIGGER_SUSPEND:
340 		prm->ss = NULL;
341 		break;
342 	default:
343 		err = -EINVAL;
344 	}
345 
346 	/* Clear buffer after Play stops */
347 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && !prm->ss)
348 		memset(prm->rbuf, 0, prm->max_psize * params->req_number);
349 
350 	return err;
351 }
352 
353 static snd_pcm_uframes_t uac_pcm_pointer(struct snd_pcm_substream *substream)
354 {
355 	struct snd_uac_chip *uac = snd_pcm_substream_chip(substream);
356 	struct uac_rtd_params *prm;
357 
358 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
359 		prm = &uac->p_prm;
360 	else
361 		prm = &uac->c_prm;
362 
363 	return bytes_to_frames(substream->runtime, prm->hw_ptr);
364 }
365 
366 static u64 uac_ssize_to_fmt(int ssize)
367 {
368 	u64 ret;
369 
370 	switch (ssize) {
371 	case 3:
372 		ret = SNDRV_PCM_FMTBIT_S24_3LE;
373 		break;
374 	case 4:
375 		ret = SNDRV_PCM_FMTBIT_S32_LE;
376 		break;
377 	default:
378 		ret = SNDRV_PCM_FMTBIT_S16_LE;
379 		break;
380 	}
381 
382 	return ret;
383 }
384 
385 static int uac_pcm_open(struct snd_pcm_substream *substream)
386 {
387 	struct snd_uac_chip *uac = snd_pcm_substream_chip(substream);
388 	struct snd_pcm_runtime *runtime = substream->runtime;
389 	struct g_audio *audio_dev;
390 	struct uac_params *params;
391 	struct uac_rtd_params *prm;
392 	int p_ssize, c_ssize;
393 	int p_chmask, c_chmask;
394 
395 	audio_dev = uac->audio_dev;
396 	params = &audio_dev->params;
397 	p_ssize = params->p_ssize;
398 	c_ssize = params->c_ssize;
399 	p_chmask = params->p_chmask;
400 	c_chmask = params->c_chmask;
401 	uac->p_residue_mil = 0;
402 
403 	runtime->hw = uac_pcm_hardware;
404 
405 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
406 		runtime->hw.formats = uac_ssize_to_fmt(p_ssize);
407 		runtime->hw.channels_min = num_channels(p_chmask);
408 		prm = &uac->p_prm;
409 	} else {
410 		runtime->hw.formats = uac_ssize_to_fmt(c_ssize);
411 		runtime->hw.channels_min = num_channels(c_chmask);
412 		prm = &uac->c_prm;
413 	}
414 
415 	runtime->hw.period_bytes_min = 2 * prm->max_psize
416 					/ runtime->hw.periods_min;
417 	runtime->hw.rate_min = prm->srate;
418 	runtime->hw.rate_max = runtime->hw.rate_min;
419 	runtime->hw.channels_max = runtime->hw.channels_min;
420 
421 	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
422 
423 	return 0;
424 }
425 
426 /* ALSA cries without these function pointers */
427 static int uac_pcm_null(struct snd_pcm_substream *substream)
428 {
429 	return 0;
430 }
431 
432 static const struct snd_pcm_ops uac_pcm_ops = {
433 	.open = uac_pcm_open,
434 	.close = uac_pcm_null,
435 	.trigger = uac_pcm_trigger,
436 	.pointer = uac_pcm_pointer,
437 	.prepare = uac_pcm_null,
438 };
439 
440 static inline void free_ep(struct uac_rtd_params *prm, struct usb_ep *ep)
441 {
442 	struct snd_uac_chip *uac = prm->uac;
443 	struct g_audio *audio_dev;
444 	struct uac_params *params;
445 	int i;
446 
447 	if (!prm->ep_enabled)
448 		return;
449 
450 	audio_dev = uac->audio_dev;
451 	params = &audio_dev->params;
452 
453 	for (i = 0; i < params->req_number; i++) {
454 		if (prm->reqs[i]) {
455 			if (usb_ep_dequeue(ep, prm->reqs[i]))
456 				usb_ep_free_request(ep, prm->reqs[i]);
457 			/*
458 			 * If usb_ep_dequeue() cannot successfully dequeue the
459 			 * request, the request will be freed by the completion
460 			 * callback.
461 			 */
462 
463 			prm->reqs[i] = NULL;
464 		}
465 	}
466 
467 	prm->ep_enabled = false;
468 
469 	if (usb_ep_disable(ep))
470 		dev_err(uac->card->dev, "%s:%d Error!\n", __func__, __LINE__);
471 }
472 
473 static inline void free_ep_fback(struct uac_rtd_params *prm, struct usb_ep *ep)
474 {
475 	struct snd_uac_chip *uac = prm->uac;
476 
477 	if (!prm->fb_ep_enabled)
478 		return;
479 
480 	if (prm->req_fback) {
481 		if (usb_ep_dequeue(ep, prm->req_fback)) {
482 			kfree(prm->req_fback->buf);
483 			usb_ep_free_request(ep, prm->req_fback);
484 		}
485 		prm->req_fback = NULL;
486 	}
487 
488 	prm->fb_ep_enabled = false;
489 
490 	if (usb_ep_disable(ep))
491 		dev_err(uac->card->dev, "%s:%d Error!\n", __func__, __LINE__);
492 }
493 
494 static void set_active(struct uac_rtd_params *prm, bool active)
495 {
496 	// notifying through the Rate ctrl
497 	unsigned long flags;
498 
499 	spin_lock_irqsave(&prm->lock, flags);
500 	if (prm->active != active) {
501 		prm->active = active;
502 		snd_ctl_notify(prm->uac->card, SNDRV_CTL_EVENT_MASK_VALUE,
503 				&prm->snd_kctl_rate_id);
504 	}
505 	spin_unlock_irqrestore(&prm->lock, flags);
506 }
507 
508 int u_audio_set_capture_srate(struct g_audio *audio_dev, int srate)
509 {
510 	struct uac_params *params = &audio_dev->params;
511 	struct snd_uac_chip *uac = audio_dev->uac;
512 	struct uac_rtd_params *prm;
513 	int i;
514 	unsigned long flags;
515 
516 	dev_dbg(&audio_dev->gadget->dev, "%s: srate %d\n", __func__, srate);
517 	prm = &uac->c_prm;
518 	for (i = 0; i < UAC_MAX_RATES; i++) {
519 		if (params->c_srates[i] == srate) {
520 			spin_lock_irqsave(&prm->lock, flags);
521 			prm->srate = srate;
522 			spin_unlock_irqrestore(&prm->lock, flags);
523 			return 0;
524 		}
525 		if (params->c_srates[i] == 0)
526 			break;
527 	}
528 
529 	return -EINVAL;
530 }
531 EXPORT_SYMBOL_GPL(u_audio_set_capture_srate);
532 
533 int u_audio_get_capture_srate(struct g_audio *audio_dev, u32 *val)
534 {
535 	struct snd_uac_chip *uac = audio_dev->uac;
536 	struct uac_rtd_params *prm;
537 	unsigned long flags;
538 
539 	prm = &uac->c_prm;
540 	spin_lock_irqsave(&prm->lock, flags);
541 	*val = prm->srate;
542 	spin_unlock_irqrestore(&prm->lock, flags);
543 	return 0;
544 }
545 EXPORT_SYMBOL_GPL(u_audio_get_capture_srate);
546 
547 int u_audio_set_playback_srate(struct g_audio *audio_dev, int srate)
548 {
549 	struct uac_params *params = &audio_dev->params;
550 	struct snd_uac_chip *uac = audio_dev->uac;
551 	struct uac_rtd_params *prm;
552 	int i;
553 	unsigned long flags;
554 
555 	dev_dbg(&audio_dev->gadget->dev, "%s: srate %d\n", __func__, srate);
556 	prm = &uac->p_prm;
557 	for (i = 0; i < UAC_MAX_RATES; i++) {
558 		if (params->p_srates[i] == srate) {
559 			spin_lock_irqsave(&prm->lock, flags);
560 			prm->srate = srate;
561 			spin_unlock_irqrestore(&prm->lock, flags);
562 			return 0;
563 		}
564 		if (params->p_srates[i] == 0)
565 			break;
566 	}
567 
568 	return -EINVAL;
569 }
570 EXPORT_SYMBOL_GPL(u_audio_set_playback_srate);
571 
572 int u_audio_get_playback_srate(struct g_audio *audio_dev, u32 *val)
573 {
574 	struct snd_uac_chip *uac = audio_dev->uac;
575 	struct uac_rtd_params *prm;
576 	unsigned long flags;
577 
578 	prm = &uac->p_prm;
579 	spin_lock_irqsave(&prm->lock, flags);
580 	*val = prm->srate;
581 	spin_unlock_irqrestore(&prm->lock, flags);
582 	return 0;
583 }
584 EXPORT_SYMBOL_GPL(u_audio_get_playback_srate);
585 
586 int u_audio_start_capture(struct g_audio *audio_dev)
587 {
588 	struct snd_uac_chip *uac = audio_dev->uac;
589 	struct usb_gadget *gadget = audio_dev->gadget;
590 	struct device *dev = &gadget->dev;
591 	struct usb_request *req, *req_fback;
592 	struct usb_ep *ep, *ep_fback;
593 	struct uac_rtd_params *prm;
594 	struct uac_params *params = &audio_dev->params;
595 	int req_len, i;
596 
597 	prm = &uac->c_prm;
598 	dev_dbg(dev, "start capture with rate %d\n", prm->srate);
599 	ep = audio_dev->out_ep;
600 	config_ep_by_speed(gadget, &audio_dev->func, ep);
601 	req_len = ep->maxpacket;
602 
603 	prm->ep_enabled = true;
604 	usb_ep_enable(ep);
605 
606 	for (i = 0; i < params->req_number; i++) {
607 		if (!prm->reqs[i]) {
608 			req = usb_ep_alloc_request(ep, GFP_ATOMIC);
609 			if (req == NULL)
610 				return -ENOMEM;
611 
612 			prm->reqs[i] = req;
613 
614 			req->zero = 0;
615 			req->context = prm;
616 			req->length = req_len;
617 			req->complete = u_audio_iso_complete;
618 			req->buf = prm->rbuf + i * ep->maxpacket;
619 		}
620 
621 		if (usb_ep_queue(ep, prm->reqs[i], GFP_ATOMIC))
622 			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
623 	}
624 
625 	set_active(&uac->c_prm, true);
626 
627 	ep_fback = audio_dev->in_ep_fback;
628 	if (!ep_fback)
629 		return 0;
630 
631 	/* Setup feedback endpoint */
632 	config_ep_by_speed(gadget, &audio_dev->func, ep_fback);
633 	prm->fb_ep_enabled = true;
634 	usb_ep_enable(ep_fback);
635 	req_len = ep_fback->maxpacket;
636 
637 	req_fback = usb_ep_alloc_request(ep_fback, GFP_ATOMIC);
638 	if (req_fback == NULL)
639 		return -ENOMEM;
640 
641 	prm->req_fback = req_fback;
642 	req_fback->zero = 0;
643 	req_fback->context = prm;
644 	req_fback->length = req_len;
645 	req_fback->complete = u_audio_iso_fback_complete;
646 
647 	req_fback->buf = kzalloc(req_len, GFP_ATOMIC);
648 	if (!req_fback->buf)
649 		return -ENOMEM;
650 
651 	/*
652 	 * Configure the feedback endpoint's reported frequency.
653 	 * Always start with original frequency since its deviation can't
654 	 * be meauserd at start of playback
655 	 */
656 	prm->pitch = 1000000;
657 	u_audio_set_fback_frequency(audio_dev->gadget->speed, ep,
658 				    prm->srate, prm->pitch,
659 				    req_fback->buf);
660 
661 	if (usb_ep_queue(ep_fback, req_fback, GFP_ATOMIC))
662 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
663 
664 	return 0;
665 }
666 EXPORT_SYMBOL_GPL(u_audio_start_capture);
667 
668 void u_audio_stop_capture(struct g_audio *audio_dev)
669 {
670 	struct snd_uac_chip *uac = audio_dev->uac;
671 
672 	set_active(&uac->c_prm, false);
673 	if (audio_dev->in_ep_fback)
674 		free_ep_fback(&uac->c_prm, audio_dev->in_ep_fback);
675 	free_ep(&uac->c_prm, audio_dev->out_ep);
676 }
677 EXPORT_SYMBOL_GPL(u_audio_stop_capture);
678 
679 int u_audio_start_playback(struct g_audio *audio_dev)
680 {
681 	struct snd_uac_chip *uac = audio_dev->uac;
682 	struct usb_gadget *gadget = audio_dev->gadget;
683 	struct device *dev = &gadget->dev;
684 	struct usb_request *req;
685 	struct usb_ep *ep;
686 	struct uac_rtd_params *prm;
687 	struct uac_params *params = &audio_dev->params;
688 	unsigned int factor;
689 	const struct usb_endpoint_descriptor *ep_desc;
690 	int req_len, i;
691 	unsigned int p_pktsize;
692 
693 	prm = &uac->p_prm;
694 	dev_dbg(dev, "start playback with rate %d\n", prm->srate);
695 	ep = audio_dev->in_ep;
696 	config_ep_by_speed(gadget, &audio_dev->func, ep);
697 
698 	ep_desc = ep->desc;
699 	/*
700 	 * Always start with original frequency
701 	 */
702 	prm->pitch = 1000000;
703 
704 	/* pre-calculate the playback endpoint's interval */
705 	if (gadget->speed == USB_SPEED_FULL)
706 		factor = 1000;
707 	else
708 		factor = 8000;
709 
710 	/* pre-compute some values for iso_complete() */
711 	uac->p_framesize = params->p_ssize *
712 			    num_channels(params->p_chmask);
713 	uac->p_interval = factor / (1 << (ep_desc->bInterval - 1));
714 	p_pktsize = min_t(unsigned int,
715 				uac->p_framesize *
716 					(prm->srate / uac->p_interval),
717 				ep->maxpacket);
718 
719 	req_len = p_pktsize;
720 	uac->p_residue_mil = 0;
721 
722 	prm->ep_enabled = true;
723 	usb_ep_enable(ep);
724 
725 	for (i = 0; i < params->req_number; i++) {
726 		if (!prm->reqs[i]) {
727 			req = usb_ep_alloc_request(ep, GFP_ATOMIC);
728 			if (req == NULL)
729 				return -ENOMEM;
730 
731 			prm->reqs[i] = req;
732 
733 			req->zero = 0;
734 			req->context = prm;
735 			req->length = req_len;
736 			req->complete = u_audio_iso_complete;
737 			req->buf = prm->rbuf + i * ep->maxpacket;
738 		}
739 
740 		if (usb_ep_queue(ep, prm->reqs[i], GFP_ATOMIC))
741 			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
742 	}
743 
744 	set_active(&uac->p_prm, true);
745 
746 	return 0;
747 }
748 EXPORT_SYMBOL_GPL(u_audio_start_playback);
749 
750 void u_audio_stop_playback(struct g_audio *audio_dev)
751 {
752 	struct snd_uac_chip *uac = audio_dev->uac;
753 
754 	set_active(&uac->p_prm, false);
755 	free_ep(&uac->p_prm, audio_dev->in_ep);
756 }
757 EXPORT_SYMBOL_GPL(u_audio_stop_playback);
758 
759 void u_audio_suspend(struct g_audio *audio_dev)
760 {
761 	struct snd_uac_chip *uac = audio_dev->uac;
762 
763 	set_active(&uac->p_prm, false);
764 	set_active(&uac->c_prm, false);
765 }
766 EXPORT_SYMBOL_GPL(u_audio_suspend);
767 
768 int u_audio_get_volume(struct g_audio *audio_dev, int playback, s16 *val)
769 {
770 	struct snd_uac_chip *uac = audio_dev->uac;
771 	struct uac_rtd_params *prm;
772 	unsigned long flags;
773 
774 	if (playback)
775 		prm = &uac->p_prm;
776 	else
777 		prm = &uac->c_prm;
778 
779 	spin_lock_irqsave(&prm->lock, flags);
780 	*val = prm->volume;
781 	spin_unlock_irqrestore(&prm->lock, flags);
782 
783 	return 0;
784 }
785 EXPORT_SYMBOL_GPL(u_audio_get_volume);
786 
787 int u_audio_set_volume(struct g_audio *audio_dev, int playback, s16 val)
788 {
789 	struct snd_uac_chip *uac = audio_dev->uac;
790 	struct uac_rtd_params *prm;
791 	unsigned long flags;
792 	int change = 0;
793 
794 	if (playback)
795 		prm = &uac->p_prm;
796 	else
797 		prm = &uac->c_prm;
798 
799 	spin_lock_irqsave(&prm->lock, flags);
800 	val = clamp(val, prm->volume_min, prm->volume_max);
801 	if (prm->volume != val) {
802 		prm->volume = val;
803 		change = 1;
804 	}
805 	spin_unlock_irqrestore(&prm->lock, flags);
806 
807 	if (change)
808 		snd_ctl_notify(uac->card, SNDRV_CTL_EVENT_MASK_VALUE,
809 				&prm->snd_kctl_volume_id);
810 
811 	return 0;
812 }
813 EXPORT_SYMBOL_GPL(u_audio_set_volume);
814 
815 int u_audio_get_mute(struct g_audio *audio_dev, int playback, int *val)
816 {
817 	struct snd_uac_chip *uac = audio_dev->uac;
818 	struct uac_rtd_params *prm;
819 	unsigned long flags;
820 
821 	if (playback)
822 		prm = &uac->p_prm;
823 	else
824 		prm = &uac->c_prm;
825 
826 	spin_lock_irqsave(&prm->lock, flags);
827 	*val = prm->mute;
828 	spin_unlock_irqrestore(&prm->lock, flags);
829 
830 	return 0;
831 }
832 EXPORT_SYMBOL_GPL(u_audio_get_mute);
833 
834 int u_audio_set_mute(struct g_audio *audio_dev, int playback, int val)
835 {
836 	struct snd_uac_chip *uac = audio_dev->uac;
837 	struct uac_rtd_params *prm;
838 	unsigned long flags;
839 	int change = 0;
840 	int mute;
841 
842 	if (playback)
843 		prm = &uac->p_prm;
844 	else
845 		prm = &uac->c_prm;
846 
847 	mute = val ? 1 : 0;
848 
849 	spin_lock_irqsave(&prm->lock, flags);
850 	if (prm->mute != mute) {
851 		prm->mute = mute;
852 		change = 1;
853 	}
854 	spin_unlock_irqrestore(&prm->lock, flags);
855 
856 	if (change)
857 		snd_ctl_notify(uac->card, SNDRV_CTL_EVENT_MASK_VALUE,
858 			       &prm->snd_kctl_mute_id);
859 
860 	return 0;
861 }
862 EXPORT_SYMBOL_GPL(u_audio_set_mute);
863 
864 
865 static int u_audio_pitch_info(struct snd_kcontrol *kcontrol,
866 				   struct snd_ctl_elem_info *uinfo)
867 {
868 	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
869 	struct snd_uac_chip *uac = prm->uac;
870 	struct g_audio *audio_dev = uac->audio_dev;
871 	struct uac_params *params = &audio_dev->params;
872 	unsigned int pitch_min, pitch_max;
873 
874 	pitch_min = (1000 - FBACK_SLOW_MAX) * 1000;
875 	pitch_max = (1000 + params->fb_max) * 1000;
876 
877 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
878 	uinfo->count = 1;
879 	uinfo->value.integer.min = pitch_min;
880 	uinfo->value.integer.max = pitch_max;
881 	uinfo->value.integer.step = 1;
882 	return 0;
883 }
884 
885 static int u_audio_pitch_get(struct snd_kcontrol *kcontrol,
886 				   struct snd_ctl_elem_value *ucontrol)
887 {
888 	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
889 
890 	ucontrol->value.integer.value[0] = prm->pitch;
891 
892 	return 0;
893 }
894 
895 static int u_audio_pitch_put(struct snd_kcontrol *kcontrol,
896 				  struct snd_ctl_elem_value *ucontrol)
897 {
898 	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
899 	struct snd_uac_chip *uac = prm->uac;
900 	struct g_audio *audio_dev = uac->audio_dev;
901 	struct uac_params *params = &audio_dev->params;
902 	unsigned int val;
903 	unsigned int pitch_min, pitch_max;
904 	int change = 0;
905 
906 	pitch_min = (1000 - FBACK_SLOW_MAX) * 1000;
907 	pitch_max = (1000 + params->fb_max) * 1000;
908 
909 	val = ucontrol->value.integer.value[0];
910 
911 	if (val < pitch_min)
912 		val = pitch_min;
913 	if (val > pitch_max)
914 		val = pitch_max;
915 
916 	if (prm->pitch != val) {
917 		prm->pitch = val;
918 		change = 1;
919 	}
920 
921 	return change;
922 }
923 
924 static int u_audio_mute_info(struct snd_kcontrol *kcontrol,
925 				   struct snd_ctl_elem_info *uinfo)
926 {
927 	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
928 	uinfo->count = 1;
929 	uinfo->value.integer.min = 0;
930 	uinfo->value.integer.max = 1;
931 	uinfo->value.integer.step = 1;
932 
933 	return 0;
934 }
935 
936 static int u_audio_mute_get(struct snd_kcontrol *kcontrol,
937 				   struct snd_ctl_elem_value *ucontrol)
938 {
939 	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
940 	unsigned long flags;
941 
942 	spin_lock_irqsave(&prm->lock, flags);
943 	ucontrol->value.integer.value[0] = !prm->mute;
944 	spin_unlock_irqrestore(&prm->lock, flags);
945 
946 	return 0;
947 }
948 
949 static int u_audio_mute_put(struct snd_kcontrol *kcontrol,
950 				  struct snd_ctl_elem_value *ucontrol)
951 {
952 	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
953 	struct snd_uac_chip *uac = prm->uac;
954 	struct g_audio *audio_dev = uac->audio_dev;
955 	unsigned int val;
956 	unsigned long flags;
957 	int change = 0;
958 
959 	val = !ucontrol->value.integer.value[0];
960 
961 	spin_lock_irqsave(&prm->lock, flags);
962 	if (val != prm->mute) {
963 		prm->mute = val;
964 		change = 1;
965 	}
966 	spin_unlock_irqrestore(&prm->lock, flags);
967 
968 	if (change && audio_dev->notify)
969 		audio_dev->notify(audio_dev, prm->fu_id, UAC_FU_MUTE);
970 
971 	return change;
972 }
973 
974 /*
975  * TLV callback for mixer volume controls
976  */
977 static int u_audio_volume_tlv(struct snd_kcontrol *kcontrol, int op_flag,
978 			 unsigned int size, unsigned int __user *_tlv)
979 {
980 	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
981 	DECLARE_TLV_DB_MINMAX(scale, 0, 0);
982 
983 	if (size < sizeof(scale))
984 		return -ENOMEM;
985 
986 	/* UAC volume resolution is 1/256 dB, TLV is 1/100 dB */
987 	scale[2] = (prm->volume_min * 100) / 256;
988 	scale[3] = (prm->volume_max * 100) / 256;
989 	if (copy_to_user(_tlv, scale, sizeof(scale)))
990 		return -EFAULT;
991 
992 	return 0;
993 }
994 
995 static int u_audio_volume_info(struct snd_kcontrol *kcontrol,
996 				   struct snd_ctl_elem_info *uinfo)
997 {
998 	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
999 
1000 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
1001 	uinfo->count = 1;
1002 	uinfo->value.integer.min = 0;
1003 	uinfo->value.integer.max =
1004 		(prm->volume_max - prm->volume_min + prm->volume_res - 1)
1005 		/ prm->volume_res;
1006 	uinfo->value.integer.step = 1;
1007 
1008 	return 0;
1009 }
1010 
1011 static int u_audio_volume_get(struct snd_kcontrol *kcontrol,
1012 				   struct snd_ctl_elem_value *ucontrol)
1013 {
1014 	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
1015 	unsigned long flags;
1016 
1017 	spin_lock_irqsave(&prm->lock, flags);
1018 	ucontrol->value.integer.value[0] =
1019 			(prm->volume - prm->volume_min) / prm->volume_res;
1020 	spin_unlock_irqrestore(&prm->lock, flags);
1021 
1022 	return 0;
1023 }
1024 
1025 static int u_audio_volume_put(struct snd_kcontrol *kcontrol,
1026 				  struct snd_ctl_elem_value *ucontrol)
1027 {
1028 	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
1029 	struct snd_uac_chip *uac = prm->uac;
1030 	struct g_audio *audio_dev = uac->audio_dev;
1031 	unsigned int val;
1032 	s16 volume;
1033 	unsigned long flags;
1034 	int change = 0;
1035 
1036 	val = ucontrol->value.integer.value[0];
1037 
1038 	spin_lock_irqsave(&prm->lock, flags);
1039 	volume = (val * prm->volume_res) + prm->volume_min;
1040 	volume = clamp(volume, prm->volume_min, prm->volume_max);
1041 	if (volume != prm->volume) {
1042 		prm->volume = volume;
1043 		change = 1;
1044 	}
1045 	spin_unlock_irqrestore(&prm->lock, flags);
1046 
1047 	if (change && audio_dev->notify)
1048 		audio_dev->notify(audio_dev, prm->fu_id, UAC_FU_VOLUME);
1049 
1050 	return change;
1051 }
1052 
1053 static int get_max_srate(const int *srates)
1054 {
1055 	int i, max_srate = 0;
1056 
1057 	for (i = 0; i < UAC_MAX_RATES; i++) {
1058 		if (srates[i] == 0)
1059 			break;
1060 		if (srates[i] > max_srate)
1061 			max_srate = srates[i];
1062 	}
1063 	return max_srate;
1064 }
1065 
1066 static int get_min_srate(const int *srates)
1067 {
1068 	int i, min_srate = INT_MAX;
1069 
1070 	for (i = 0; i < UAC_MAX_RATES; i++) {
1071 		if (srates[i] == 0)
1072 			break;
1073 		if (srates[i] < min_srate)
1074 			min_srate = srates[i];
1075 	}
1076 	return min_srate;
1077 }
1078 
1079 static int u_audio_rate_info(struct snd_kcontrol *kcontrol,
1080 				struct snd_ctl_elem_info *uinfo)
1081 {
1082 	const int *srates;
1083 	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
1084 	struct snd_uac_chip *uac = prm->uac;
1085 	struct g_audio *audio_dev = uac->audio_dev;
1086 	struct uac_params *params = &audio_dev->params;
1087 
1088 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
1089 	uinfo->count = 1;
1090 
1091 	if (prm == &uac->c_prm)
1092 		srates = params->c_srates;
1093 	else
1094 		srates = params->p_srates;
1095 	uinfo->value.integer.min = get_min_srate(srates);
1096 	uinfo->value.integer.max = get_max_srate(srates);
1097 	return 0;
1098 }
1099 
1100 static int u_audio_rate_get(struct snd_kcontrol *kcontrol,
1101 						 struct snd_ctl_elem_value *ucontrol)
1102 {
1103 	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
1104 	unsigned long flags;
1105 
1106 	spin_lock_irqsave(&prm->lock, flags);
1107 	if (prm->active)
1108 		ucontrol->value.integer.value[0] = prm->srate;
1109 	else
1110 		/* not active: reporting zero rate */
1111 		ucontrol->value.integer.value[0] = 0;
1112 	spin_unlock_irqrestore(&prm->lock, flags);
1113 	return 0;
1114 }
1115 
1116 static struct snd_kcontrol_new u_audio_controls[]  = {
1117   [UAC_FBACK_CTRL] {
1118     .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
1119     .name =         "Capture Pitch 1000000",
1120     .info =         u_audio_pitch_info,
1121     .get =          u_audio_pitch_get,
1122     .put =          u_audio_pitch_put,
1123   },
1124 	[UAC_P_PITCH_CTRL] {
1125 		.iface =        SNDRV_CTL_ELEM_IFACE_PCM,
1126 		.name =         "Playback Pitch 1000000",
1127 		.info =         u_audio_pitch_info,
1128 		.get =          u_audio_pitch_get,
1129 		.put =          u_audio_pitch_put,
1130 	},
1131   [UAC_MUTE_CTRL] {
1132 		.iface =	SNDRV_CTL_ELEM_IFACE_MIXER,
1133 		.name =		"", /* will be filled later */
1134 		.info =		u_audio_mute_info,
1135 		.get =		u_audio_mute_get,
1136 		.put =		u_audio_mute_put,
1137 	},
1138 	[UAC_VOLUME_CTRL] {
1139 		.iface =	SNDRV_CTL_ELEM_IFACE_MIXER,
1140 		.name =		"", /* will be filled later */
1141 		.info =		u_audio_volume_info,
1142 		.get =		u_audio_volume_get,
1143 		.put =		u_audio_volume_put,
1144 	},
1145 	[UAC_RATE_CTRL] {
1146 		.iface =	SNDRV_CTL_ELEM_IFACE_PCM,
1147 		.name =		"", /* will be filled later */
1148 		.access =	SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
1149 		.info =		u_audio_rate_info,
1150 		.get =		u_audio_rate_get,
1151 	},
1152 };
1153 
1154 int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
1155 					const char *card_name)
1156 {
1157 	struct snd_uac_chip *uac;
1158 	struct snd_card *card;
1159 	struct snd_pcm *pcm;
1160 	struct snd_kcontrol *kctl;
1161 	struct uac_params *params;
1162 	int p_chmask, c_chmask;
1163 	int i, err;
1164 
1165 	if (!g_audio)
1166 		return -EINVAL;
1167 
1168 	uac = kzalloc(sizeof(*uac), GFP_KERNEL);
1169 	if (!uac)
1170 		return -ENOMEM;
1171 	g_audio->uac = uac;
1172 	uac->audio_dev = g_audio;
1173 
1174 	params = &g_audio->params;
1175 	p_chmask = params->p_chmask;
1176 	c_chmask = params->c_chmask;
1177 
1178 	if (c_chmask) {
1179 		struct uac_rtd_params *prm = &uac->c_prm;
1180 
1181 		spin_lock_init(&prm->lock);
1182 		uac->c_prm.uac = uac;
1183 		prm->max_psize = g_audio->out_ep_maxpsize;
1184 		prm->srate = params->c_srates[0];
1185 
1186 		prm->reqs = kcalloc(params->req_number,
1187 				    sizeof(struct usb_request *),
1188 				    GFP_KERNEL);
1189 		if (!prm->reqs) {
1190 			err = -ENOMEM;
1191 			goto fail;
1192 		}
1193 
1194 		prm->rbuf = kcalloc(params->req_number, prm->max_psize,
1195 				GFP_KERNEL);
1196 		if (!prm->rbuf) {
1197 			prm->max_psize = 0;
1198 			err = -ENOMEM;
1199 			goto fail;
1200 		}
1201 	}
1202 
1203 	if (p_chmask) {
1204 		struct uac_rtd_params *prm = &uac->p_prm;
1205 
1206 		spin_lock_init(&prm->lock);
1207 		uac->p_prm.uac = uac;
1208 		prm->max_psize = g_audio->in_ep_maxpsize;
1209 		prm->srate = params->p_srates[0];
1210 
1211 		prm->reqs = kcalloc(params->req_number,
1212 				    sizeof(struct usb_request *),
1213 				    GFP_KERNEL);
1214 		if (!prm->reqs) {
1215 			err = -ENOMEM;
1216 			goto fail;
1217 		}
1218 
1219 		prm->rbuf = kcalloc(params->req_number, prm->max_psize,
1220 				GFP_KERNEL);
1221 		if (!prm->rbuf) {
1222 			prm->max_psize = 0;
1223 			err = -ENOMEM;
1224 			goto fail;
1225 		}
1226 	}
1227 
1228 	/* Choose any slot, with no id */
1229 	err = snd_card_new(&g_audio->gadget->dev,
1230 			-1, NULL, THIS_MODULE, 0, &card);
1231 	if (err < 0)
1232 		goto fail;
1233 
1234 	uac->card = card;
1235 
1236 	/*
1237 	 * Create first PCM device
1238 	 * Create a substream only for non-zero channel streams
1239 	 */
1240 	err = snd_pcm_new(uac->card, pcm_name, 0,
1241 			       p_chmask ? 1 : 0, c_chmask ? 1 : 0, &pcm);
1242 	if (err < 0)
1243 		goto snd_fail;
1244 
1245 	strscpy(pcm->name, pcm_name);
1246 	pcm->private_data = uac;
1247 	uac->pcm = pcm;
1248 
1249 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &uac_pcm_ops);
1250 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &uac_pcm_ops);
1251 
1252 	/*
1253 	 * Create mixer and controls
1254 	 * Create only if it's required on USB side
1255 	 */
1256 	if ((c_chmask && g_audio->in_ep_fback)
1257 			|| (p_chmask && params->p_fu.id)
1258 			|| (c_chmask && params->c_fu.id))
1259 		strscpy(card->mixername, card_name);
1260 
1261 	if (c_chmask && g_audio->in_ep_fback) {
1262 		kctl = snd_ctl_new1(&u_audio_controls[UAC_FBACK_CTRL],
1263 				    &uac->c_prm);
1264 		if (!kctl) {
1265 			err = -ENOMEM;
1266 			goto snd_fail;
1267 		}
1268 
1269 		kctl->id.device = pcm->device;
1270 		kctl->id.subdevice = 0;
1271 
1272 		err = snd_ctl_add(card, kctl);
1273 		if (err < 0)
1274 			goto snd_fail;
1275 	}
1276 
1277 	if (p_chmask) {
1278 		kctl = snd_ctl_new1(&u_audio_controls[UAC_P_PITCH_CTRL],
1279 				    &uac->p_prm);
1280 		if (!kctl) {
1281 			err = -ENOMEM;
1282 			goto snd_fail;
1283 		}
1284 
1285 		kctl->id.device = pcm->device;
1286 		kctl->id.subdevice = 0;
1287 
1288 		err = snd_ctl_add(card, kctl);
1289 		if (err < 0)
1290 			goto snd_fail;
1291 	}
1292 
1293 	for (i = 0; i <= SNDRV_PCM_STREAM_LAST; i++) {
1294 		struct uac_rtd_params *prm;
1295 		struct uac_fu_params *fu;
1296 		char ctrl_name[24];
1297 		char *direction;
1298 
1299 		if (!pcm->streams[i].substream_count)
1300 			continue;
1301 
1302 		if (i == SNDRV_PCM_STREAM_PLAYBACK) {
1303 			prm = &uac->p_prm;
1304 			fu = &params->p_fu;
1305 			direction = "Playback";
1306 		} else {
1307 			prm = &uac->c_prm;
1308 			fu = &params->c_fu;
1309 			direction = "Capture";
1310 		}
1311 
1312 		prm->fu_id = fu->id;
1313 
1314 		if (fu->mute_present) {
1315 			snprintf(ctrl_name, sizeof(ctrl_name),
1316 					"PCM %s Switch", direction);
1317 
1318 			u_audio_controls[UAC_MUTE_CTRL].name = ctrl_name;
1319 
1320 			kctl = snd_ctl_new1(&u_audio_controls[UAC_MUTE_CTRL],
1321 					    prm);
1322 			if (!kctl) {
1323 				err = -ENOMEM;
1324 				goto snd_fail;
1325 			}
1326 
1327 			kctl->id.device = pcm->device;
1328 			kctl->id.subdevice = 0;
1329 
1330 			err = snd_ctl_add(card, kctl);
1331 			if (err < 0)
1332 				goto snd_fail;
1333 			prm->snd_kctl_mute_id = kctl->id;
1334 			prm->mute = 0;
1335 		}
1336 
1337 		if (fu->volume_present) {
1338 			snprintf(ctrl_name, sizeof(ctrl_name),
1339 					"PCM %s Volume", direction);
1340 
1341 			u_audio_controls[UAC_VOLUME_CTRL].name = ctrl_name;
1342 
1343 			kctl = snd_ctl_new1(&u_audio_controls[UAC_VOLUME_CTRL],
1344 					    prm);
1345 			if (!kctl) {
1346 				err = -ENOMEM;
1347 				goto snd_fail;
1348 			}
1349 
1350 			kctl->id.device = pcm->device;
1351 			kctl->id.subdevice = 0;
1352 
1353 
1354 			kctl->tlv.c = u_audio_volume_tlv;
1355 			kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ |
1356 					SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
1357 
1358 			err = snd_ctl_add(card, kctl);
1359 			if (err < 0)
1360 				goto snd_fail;
1361 			prm->snd_kctl_volume_id = kctl->id;
1362 			prm->volume = fu->volume_max;
1363 			prm->volume_max = fu->volume_max;
1364 			prm->volume_min = fu->volume_min;
1365 			prm->volume_res = fu->volume_res;
1366 		}
1367 
1368 		/* Add rate control */
1369 		snprintf(ctrl_name, sizeof(ctrl_name),
1370 				"%s Rate", direction);
1371 		u_audio_controls[UAC_RATE_CTRL].name = ctrl_name;
1372 
1373 		kctl = snd_ctl_new1(&u_audio_controls[UAC_RATE_CTRL], prm);
1374 		if (!kctl) {
1375 			err = -ENOMEM;
1376 			goto snd_fail;
1377 		}
1378 
1379 		kctl->id.device = pcm->device;
1380 		kctl->id.subdevice = 0;
1381 
1382 		err = snd_ctl_add(card, kctl);
1383 		if (err < 0)
1384 			goto snd_fail;
1385 		prm->snd_kctl_rate_id = kctl->id;
1386 	}
1387 
1388 	strscpy(card->driver, card_name);
1389 	strscpy(card->shortname, card_name);
1390 	snprintf(card->longname, sizeof(card->longname), "%s %i",
1391 		 card_name, card->dev->id);
1392 
1393 	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
1394 				       NULL, 0, BUFF_SIZE_MAX);
1395 
1396 	err = snd_card_register(card);
1397 
1398 	if (!err)
1399 		return 0;
1400 
1401 snd_fail:
1402 	snd_card_free(card);
1403 fail:
1404 	kfree(uac->p_prm.reqs);
1405 	kfree(uac->c_prm.reqs);
1406 	kfree(uac->p_prm.rbuf);
1407 	kfree(uac->c_prm.rbuf);
1408 	kfree(uac);
1409 
1410 	return err;
1411 }
1412 EXPORT_SYMBOL_GPL(g_audio_setup);
1413 
1414 void g_audio_cleanup(struct g_audio *g_audio)
1415 {
1416 	struct snd_uac_chip *uac;
1417 	struct snd_card *card;
1418 
1419 	if (!g_audio || !g_audio->uac)
1420 		return;
1421 
1422 	uac = g_audio->uac;
1423 	g_audio->uac = NULL;
1424 
1425 	card = uac->card;
1426 	if (card)
1427 		snd_card_free_when_closed(card);
1428 
1429 	kfree(uac->p_prm.reqs);
1430 	kfree(uac->c_prm.reqs);
1431 	kfree(uac->p_prm.rbuf);
1432 	kfree(uac->c_prm.rbuf);
1433 	kfree(uac);
1434 }
1435 EXPORT_SYMBOL_GPL(g_audio_cleanup);
1436 
1437 MODULE_LICENSE("GPL");
1438 MODULE_DESCRIPTION("USB gadget \"ALSA sound card\" utilities");
1439 MODULE_AUTHOR("Ruslan Bilovol");
1440