1 /*
2  * f_uac2.c -- USB Audio Class 2.0 Function
3  *
4  * Copyright (C) 2011
5  *    Yadwinder Singh (yadi.brar01@gmail.com)
6  *    Jaswinder Singh (jaswinder.singh@linaro.org)
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  */
13 
14 #include <linux/usb/audio.h>
15 #include <linux/usb/audio-v2.h>
16 #include <linux/platform_device.h>
17 #include <linux/module.h>
18 
19 #include <sound/core.h>
20 #include <sound/pcm.h>
21 #include <sound/pcm_params.h>
22 
23 #include "u_uac2.h"
24 
25 /* Keep everyone on toes */
26 #define USB_XFERS	2
27 
28 /*
29  * The driver implements a simple UAC_2 topology.
30  * USB-OUT -> IT_1 -> OT_3 -> ALSA_Capture
31  * ALSA_Playback -> IT_2 -> OT_4 -> USB-IN
32  * Capture and Playback sampling rates are independently
33  *  controlled by two clock sources :
34  *    CLK_5 := c_srate, and CLK_6 := p_srate
35  */
36 #define USB_OUT_IT_ID	1
37 #define IO_IN_IT_ID	2
38 #define IO_OUT_OT_ID	3
39 #define USB_IN_OT_ID	4
40 #define USB_OUT_CLK_ID	5
41 #define USB_IN_CLK_ID	6
42 
43 #define CONTROL_ABSENT	0
44 #define CONTROL_RDONLY	1
45 #define CONTROL_RDWR	3
46 
47 #define CLK_FREQ_CTRL	0
48 #define CLK_VLD_CTRL	2
49 
50 #define COPY_CTRL	0
51 #define CONN_CTRL	2
52 #define OVRLD_CTRL	4
53 #define CLSTR_CTRL	6
54 #define UNFLW_CTRL	8
55 #define OVFLW_CTRL	10
56 
57 static const char *uac2_name = "snd_uac2";
58 
59 struct uac2_req {
60 	struct uac2_rtd_params *pp; /* parent param */
61 	struct usb_request *req;
62 };
63 
64 struct uac2_rtd_params {
65 	struct snd_uac2_chip *uac2; /* parent chip */
66 	bool ep_enabled; /* if the ep is enabled */
67 	/* Size of the ring buffer */
68 	size_t dma_bytes;
69 	unsigned char *dma_area;
70 
71 	struct snd_pcm_substream *ss;
72 
73 	/* Ring buffer */
74 	ssize_t hw_ptr;
75 
76 	void *rbuf;
77 
78 	size_t period_size;
79 
80 	unsigned max_psize;
81 	struct uac2_req ureq[USB_XFERS];
82 
83 	spinlock_t lock;
84 };
85 
86 struct snd_uac2_chip {
87 	struct platform_device pdev;
88 	struct platform_driver pdrv;
89 
90 	struct uac2_rtd_params p_prm;
91 	struct uac2_rtd_params c_prm;
92 
93 	struct snd_card *card;
94 	struct snd_pcm *pcm;
95 
96 	/* timekeeping for the playback endpoint */
97 	unsigned int p_interval;
98 	unsigned int p_residue;
99 
100 	/* pre-calculated values for playback iso completion */
101 	unsigned int p_pktsize;
102 	unsigned int p_pktsize_residue;
103 	unsigned int p_framesize;
104 };
105 
106 #define BUFF_SIZE_MAX	(PAGE_SIZE * 16)
107 #define PRD_SIZE_MAX	PAGE_SIZE
108 #define MIN_PERIODS	4
109 
110 static struct snd_pcm_hardware uac2_pcm_hardware = {
111 	.info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER
112 		 | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID
113 		 | SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME,
114 	.rates = SNDRV_PCM_RATE_CONTINUOUS,
115 	.periods_max = BUFF_SIZE_MAX / PRD_SIZE_MAX,
116 	.buffer_bytes_max = BUFF_SIZE_MAX,
117 	.period_bytes_max = PRD_SIZE_MAX,
118 	.periods_min = MIN_PERIODS,
119 };
120 
121 struct audio_dev {
122 	u8 ac_intf, ac_alt;
123 	u8 as_out_intf, as_out_alt;
124 	u8 as_in_intf, as_in_alt;
125 
126 	struct usb_ep *in_ep, *out_ep;
127 	struct usb_function func;
128 
129 	/* The ALSA Sound Card it represents on the USB-Client side */
130 	struct snd_uac2_chip uac2;
131 };
132 
133 static inline
134 struct audio_dev *func_to_agdev(struct usb_function *f)
135 {
136 	return container_of(f, struct audio_dev, func);
137 }
138 
139 static inline
140 struct audio_dev *uac2_to_agdev(struct snd_uac2_chip *u)
141 {
142 	return container_of(u, struct audio_dev, uac2);
143 }
144 
145 static inline
146 struct snd_uac2_chip *pdev_to_uac2(struct platform_device *p)
147 {
148 	return container_of(p, struct snd_uac2_chip, pdev);
149 }
150 
151 static inline
152 struct f_uac2_opts *agdev_to_uac2_opts(struct audio_dev *agdev)
153 {
154 	return container_of(agdev->func.fi, struct f_uac2_opts, func_inst);
155 }
156 
157 static inline
158 uint num_channels(uint chanmask)
159 {
160 	uint num = 0;
161 
162 	while (chanmask) {
163 		num += (chanmask & 1);
164 		chanmask >>= 1;
165 	}
166 
167 	return num;
168 }
169 
170 static void
171 agdev_iso_complete(struct usb_ep *ep, struct usb_request *req)
172 {
173 	unsigned pending;
174 	unsigned long flags;
175 	unsigned int hw_ptr;
176 	bool update_alsa = false;
177 	int status = req->status;
178 	struct uac2_req *ur = req->context;
179 	struct snd_pcm_substream *substream;
180 	struct uac2_rtd_params *prm = ur->pp;
181 	struct snd_uac2_chip *uac2 = prm->uac2;
182 
183 	/* i/f shutting down */
184 	if (!prm->ep_enabled || req->status == -ESHUTDOWN)
185 		return;
186 
187 	/*
188 	 * We can't really do much about bad xfers.
189 	 * Afterall, the ISOCH xfers could fail legitimately.
190 	 */
191 	if (status)
192 		pr_debug("%s: iso_complete status(%d) %d/%d\n",
193 			__func__, status, req->actual, req->length);
194 
195 	substream = prm->ss;
196 
197 	/* Do nothing if ALSA isn't active */
198 	if (!substream)
199 		goto exit;
200 
201 	spin_lock_irqsave(&prm->lock, flags);
202 
203 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
204 		/*
205 		 * For each IN packet, take the quotient of the current data
206 		 * rate and the endpoint's interval as the base packet size.
207 		 * If there is a residue from this division, add it to the
208 		 * residue accumulator.
209 		 */
210 		req->length = uac2->p_pktsize;
211 		uac2->p_residue += uac2->p_pktsize_residue;
212 
213 		/*
214 		 * Whenever there are more bytes in the accumulator than we
215 		 * need to add one more sample frame, increase this packet's
216 		 * size and decrease the accumulator.
217 		 */
218 		if (uac2->p_residue / uac2->p_interval >= uac2->p_framesize) {
219 			req->length += uac2->p_framesize;
220 			uac2->p_residue -= uac2->p_framesize *
221 					   uac2->p_interval;
222 		}
223 
224 		req->actual = req->length;
225 	}
226 
227 	pending = prm->hw_ptr % prm->period_size;
228 	pending += req->actual;
229 	if (pending >= prm->period_size)
230 		update_alsa = true;
231 
232 	hw_ptr = prm->hw_ptr;
233 	prm->hw_ptr = (prm->hw_ptr + req->actual) % prm->dma_bytes;
234 
235 	spin_unlock_irqrestore(&prm->lock, flags);
236 
237 	/* Pack USB load in ALSA ring buffer */
238 	pending = prm->dma_bytes - hw_ptr;
239 
240 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
241 		if (unlikely(pending < req->actual)) {
242 			memcpy(req->buf, prm->dma_area + hw_ptr, pending);
243 			memcpy(req->buf + pending, prm->dma_area,
244 			       req->actual - pending);
245 		} else {
246 			memcpy(req->buf, prm->dma_area + hw_ptr, req->actual);
247 		}
248 	} else {
249 		if (unlikely(pending < req->actual)) {
250 			memcpy(prm->dma_area + hw_ptr, req->buf, pending);
251 			memcpy(prm->dma_area, req->buf + pending,
252 			       req->actual - pending);
253 		} else {
254 			memcpy(prm->dma_area + hw_ptr, req->buf, req->actual);
255 		}
256 	}
257 
258 exit:
259 	if (usb_ep_queue(ep, req, GFP_ATOMIC))
260 		dev_err(&uac2->pdev.dev, "%d Error!\n", __LINE__);
261 
262 	if (update_alsa)
263 		snd_pcm_period_elapsed(substream);
264 
265 	return;
266 }
267 
268 static int
269 uac2_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
270 {
271 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
272 	struct uac2_rtd_params *prm;
273 	unsigned long flags;
274 	int err = 0;
275 
276 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
277 		prm = &uac2->p_prm;
278 	else
279 		prm = &uac2->c_prm;
280 
281 	spin_lock_irqsave(&prm->lock, flags);
282 
283 	/* Reset */
284 	prm->hw_ptr = 0;
285 
286 	switch (cmd) {
287 	case SNDRV_PCM_TRIGGER_START:
288 	case SNDRV_PCM_TRIGGER_RESUME:
289 		prm->ss = substream;
290 		break;
291 	case SNDRV_PCM_TRIGGER_STOP:
292 	case SNDRV_PCM_TRIGGER_SUSPEND:
293 		prm->ss = NULL;
294 		break;
295 	default:
296 		err = -EINVAL;
297 	}
298 
299 	spin_unlock_irqrestore(&prm->lock, flags);
300 
301 	/* Clear buffer after Play stops */
302 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && !prm->ss)
303 		memset(prm->rbuf, 0, prm->max_psize * USB_XFERS);
304 
305 	return err;
306 }
307 
308 static snd_pcm_uframes_t uac2_pcm_pointer(struct snd_pcm_substream *substream)
309 {
310 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
311 	struct uac2_rtd_params *prm;
312 
313 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
314 		prm = &uac2->p_prm;
315 	else
316 		prm = &uac2->c_prm;
317 
318 	return bytes_to_frames(substream->runtime, prm->hw_ptr);
319 }
320 
321 static int uac2_pcm_hw_params(struct snd_pcm_substream *substream,
322 			       struct snd_pcm_hw_params *hw_params)
323 {
324 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
325 	struct uac2_rtd_params *prm;
326 	int err;
327 
328 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
329 		prm = &uac2->p_prm;
330 	else
331 		prm = &uac2->c_prm;
332 
333 	err = snd_pcm_lib_malloc_pages(substream,
334 					params_buffer_bytes(hw_params));
335 	if (err >= 0) {
336 		prm->dma_bytes = substream->runtime->dma_bytes;
337 		prm->dma_area = substream->runtime->dma_area;
338 		prm->period_size = params_period_bytes(hw_params);
339 	}
340 
341 	return err;
342 }
343 
344 static int uac2_pcm_hw_free(struct snd_pcm_substream *substream)
345 {
346 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
347 	struct uac2_rtd_params *prm;
348 
349 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
350 		prm = &uac2->p_prm;
351 	else
352 		prm = &uac2->c_prm;
353 
354 	prm->dma_area = NULL;
355 	prm->dma_bytes = 0;
356 	prm->period_size = 0;
357 
358 	return snd_pcm_lib_free_pages(substream);
359 }
360 
361 static int uac2_pcm_open(struct snd_pcm_substream *substream)
362 {
363 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
364 	struct snd_pcm_runtime *runtime = substream->runtime;
365 	struct audio_dev *audio_dev;
366 	struct f_uac2_opts *opts;
367 	int p_ssize, c_ssize;
368 	int p_srate, c_srate;
369 	int p_chmask, c_chmask;
370 
371 	audio_dev = uac2_to_agdev(uac2);
372 	opts = container_of(audio_dev->func.fi, struct f_uac2_opts, func_inst);
373 	p_ssize = opts->p_ssize;
374 	c_ssize = opts->c_ssize;
375 	p_srate = opts->p_srate;
376 	c_srate = opts->c_srate;
377 	p_chmask = opts->p_chmask;
378 	c_chmask = opts->c_chmask;
379 	uac2->p_residue = 0;
380 
381 	runtime->hw = uac2_pcm_hardware;
382 
383 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
384 		spin_lock_init(&uac2->p_prm.lock);
385 		runtime->hw.rate_min = p_srate;
386 		switch (p_ssize) {
387 		case 3:
388 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S24_3LE;
389 			break;
390 		case 4:
391 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S32_LE;
392 			break;
393 		default:
394 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S16_LE;
395 			break;
396 		}
397 		runtime->hw.channels_min = num_channels(p_chmask);
398 		runtime->hw.period_bytes_min = 2 * uac2->p_prm.max_psize
399 						/ runtime->hw.periods_min;
400 	} else {
401 		spin_lock_init(&uac2->c_prm.lock);
402 		runtime->hw.rate_min = c_srate;
403 		switch (c_ssize) {
404 		case 3:
405 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S24_3LE;
406 			break;
407 		case 4:
408 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S32_LE;
409 			break;
410 		default:
411 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S16_LE;
412 			break;
413 		}
414 		runtime->hw.channels_min = num_channels(c_chmask);
415 		runtime->hw.period_bytes_min = 2 * uac2->c_prm.max_psize
416 						/ runtime->hw.periods_min;
417 	}
418 
419 	runtime->hw.rate_max = runtime->hw.rate_min;
420 	runtime->hw.channels_max = runtime->hw.channels_min;
421 
422 	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
423 
424 	return 0;
425 }
426 
427 /* ALSA cries without these function pointers */
428 static int uac2_pcm_null(struct snd_pcm_substream *substream)
429 {
430 	return 0;
431 }
432 
433 static struct snd_pcm_ops uac2_pcm_ops = {
434 	.open = uac2_pcm_open,
435 	.close = uac2_pcm_null,
436 	.ioctl = snd_pcm_lib_ioctl,
437 	.hw_params = uac2_pcm_hw_params,
438 	.hw_free = uac2_pcm_hw_free,
439 	.trigger = uac2_pcm_trigger,
440 	.pointer = uac2_pcm_pointer,
441 	.prepare = uac2_pcm_null,
442 };
443 
444 static int snd_uac2_probe(struct platform_device *pdev)
445 {
446 	struct snd_uac2_chip *uac2 = pdev_to_uac2(pdev);
447 	struct snd_card *card;
448 	struct snd_pcm *pcm;
449 	struct audio_dev *audio_dev;
450 	struct f_uac2_opts *opts;
451 	int err;
452 	int p_chmask, c_chmask;
453 
454 	audio_dev = uac2_to_agdev(uac2);
455 	opts = container_of(audio_dev->func.fi, struct f_uac2_opts, func_inst);
456 	p_chmask = opts->p_chmask;
457 	c_chmask = opts->c_chmask;
458 
459 	/* Choose any slot, with no id */
460 	err = snd_card_new(&pdev->dev, -1, NULL, THIS_MODULE, 0, &card);
461 	if (err < 0)
462 		return err;
463 
464 	uac2->card = card;
465 
466 	/*
467 	 * Create first PCM device
468 	 * Create a substream only for non-zero channel streams
469 	 */
470 	err = snd_pcm_new(uac2->card, "UAC2 PCM", 0,
471 			       p_chmask ? 1 : 0, c_chmask ? 1 : 0, &pcm);
472 	if (err < 0)
473 		goto snd_fail;
474 
475 	strcpy(pcm->name, "UAC2 PCM");
476 	pcm->private_data = uac2;
477 
478 	uac2->pcm = pcm;
479 
480 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &uac2_pcm_ops);
481 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &uac2_pcm_ops);
482 
483 	strcpy(card->driver, "UAC2_Gadget");
484 	strcpy(card->shortname, "UAC2_Gadget");
485 	sprintf(card->longname, "UAC2_Gadget %i", pdev->id);
486 
487 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
488 		snd_dma_continuous_data(GFP_KERNEL), 0, BUFF_SIZE_MAX);
489 
490 	err = snd_card_register(card);
491 	if (!err) {
492 		platform_set_drvdata(pdev, card);
493 		return 0;
494 	}
495 
496 snd_fail:
497 	snd_card_free(card);
498 
499 	uac2->pcm = NULL;
500 	uac2->card = NULL;
501 
502 	return err;
503 }
504 
505 static int snd_uac2_remove(struct platform_device *pdev)
506 {
507 	struct snd_card *card = platform_get_drvdata(pdev);
508 
509 	if (card)
510 		return snd_card_free(card);
511 
512 	return 0;
513 }
514 
515 static void snd_uac2_release(struct device *dev)
516 {
517 	dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
518 }
519 
520 static int alsa_uac2_init(struct audio_dev *agdev)
521 {
522 	struct snd_uac2_chip *uac2 = &agdev->uac2;
523 	int err;
524 
525 	uac2->pdrv.probe = snd_uac2_probe;
526 	uac2->pdrv.remove = snd_uac2_remove;
527 	uac2->pdrv.driver.name = uac2_name;
528 
529 	uac2->pdev.id = 0;
530 	uac2->pdev.name = uac2_name;
531 	uac2->pdev.dev.release = snd_uac2_release;
532 
533 	/* Register snd_uac2 driver */
534 	err = platform_driver_register(&uac2->pdrv);
535 	if (err)
536 		return err;
537 
538 	/* Register snd_uac2 device */
539 	err = platform_device_register(&uac2->pdev);
540 	if (err)
541 		platform_driver_unregister(&uac2->pdrv);
542 
543 	return err;
544 }
545 
546 static void alsa_uac2_exit(struct audio_dev *agdev)
547 {
548 	struct snd_uac2_chip *uac2 = &agdev->uac2;
549 
550 	platform_driver_unregister(&uac2->pdrv);
551 	platform_device_unregister(&uac2->pdev);
552 }
553 
554 
555 /* --------- USB Function Interface ------------- */
556 
557 enum {
558 	STR_ASSOC,
559 	STR_IF_CTRL,
560 	STR_CLKSRC_IN,
561 	STR_CLKSRC_OUT,
562 	STR_USB_IT,
563 	STR_IO_IT,
564 	STR_USB_OT,
565 	STR_IO_OT,
566 	STR_AS_OUT_ALT0,
567 	STR_AS_OUT_ALT1,
568 	STR_AS_IN_ALT0,
569 	STR_AS_IN_ALT1,
570 };
571 
572 static char clksrc_in[8];
573 static char clksrc_out[8];
574 
575 static struct usb_string strings_fn[] = {
576 	[STR_ASSOC].s = "Source/Sink",
577 	[STR_IF_CTRL].s = "Topology Control",
578 	[STR_CLKSRC_IN].s = clksrc_in,
579 	[STR_CLKSRC_OUT].s = clksrc_out,
580 	[STR_USB_IT].s = "USBH Out",
581 	[STR_IO_IT].s = "USBD Out",
582 	[STR_USB_OT].s = "USBH In",
583 	[STR_IO_OT].s = "USBD In",
584 	[STR_AS_OUT_ALT0].s = "Playback Inactive",
585 	[STR_AS_OUT_ALT1].s = "Playback Active",
586 	[STR_AS_IN_ALT0].s = "Capture Inactive",
587 	[STR_AS_IN_ALT1].s = "Capture Active",
588 	{ },
589 };
590 
591 static struct usb_gadget_strings str_fn = {
592 	.language = 0x0409,	/* en-us */
593 	.strings = strings_fn,
594 };
595 
596 static struct usb_gadget_strings *fn_strings[] = {
597 	&str_fn,
598 	NULL,
599 };
600 
601 static struct usb_interface_assoc_descriptor iad_desc = {
602 	.bLength = sizeof iad_desc,
603 	.bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
604 
605 	.bFirstInterface = 0,
606 	.bInterfaceCount = 3,
607 	.bFunctionClass = USB_CLASS_AUDIO,
608 	.bFunctionSubClass = UAC2_FUNCTION_SUBCLASS_UNDEFINED,
609 	.bFunctionProtocol = UAC_VERSION_2,
610 };
611 
612 /* Audio Control Interface */
613 static struct usb_interface_descriptor std_ac_if_desc = {
614 	.bLength = sizeof std_ac_if_desc,
615 	.bDescriptorType = USB_DT_INTERFACE,
616 
617 	.bAlternateSetting = 0,
618 	.bNumEndpoints = 0,
619 	.bInterfaceClass = USB_CLASS_AUDIO,
620 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL,
621 	.bInterfaceProtocol = UAC_VERSION_2,
622 };
623 
624 /* Clock source for IN traffic */
625 static struct uac_clock_source_descriptor in_clk_src_desc = {
626 	.bLength = sizeof in_clk_src_desc,
627 	.bDescriptorType = USB_DT_CS_INTERFACE,
628 
629 	.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
630 	.bClockID = USB_IN_CLK_ID,
631 	.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
632 	.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
633 	.bAssocTerminal = 0,
634 };
635 
636 /* Clock source for OUT traffic */
637 static struct uac_clock_source_descriptor out_clk_src_desc = {
638 	.bLength = sizeof out_clk_src_desc,
639 	.bDescriptorType = USB_DT_CS_INTERFACE,
640 
641 	.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
642 	.bClockID = USB_OUT_CLK_ID,
643 	.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
644 	.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
645 	.bAssocTerminal = 0,
646 };
647 
648 /* Input Terminal for USB_OUT */
649 static struct uac2_input_terminal_descriptor usb_out_it_desc = {
650 	.bLength = sizeof usb_out_it_desc,
651 	.bDescriptorType = USB_DT_CS_INTERFACE,
652 
653 	.bDescriptorSubtype = UAC_INPUT_TERMINAL,
654 	.bTerminalID = USB_OUT_IT_ID,
655 	.wTerminalType = cpu_to_le16(UAC_TERMINAL_STREAMING),
656 	.bAssocTerminal = 0,
657 	.bCSourceID = USB_OUT_CLK_ID,
658 	.iChannelNames = 0,
659 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
660 };
661 
662 /* Input Terminal for I/O-In */
663 static struct uac2_input_terminal_descriptor io_in_it_desc = {
664 	.bLength = sizeof io_in_it_desc,
665 	.bDescriptorType = USB_DT_CS_INTERFACE,
666 
667 	.bDescriptorSubtype = UAC_INPUT_TERMINAL,
668 	.bTerminalID = IO_IN_IT_ID,
669 	.wTerminalType = cpu_to_le16(UAC_INPUT_TERMINAL_UNDEFINED),
670 	.bAssocTerminal = 0,
671 	.bCSourceID = USB_IN_CLK_ID,
672 	.iChannelNames = 0,
673 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
674 };
675 
676 /* Ouput Terminal for USB_IN */
677 static struct uac2_output_terminal_descriptor usb_in_ot_desc = {
678 	.bLength = sizeof usb_in_ot_desc,
679 	.bDescriptorType = USB_DT_CS_INTERFACE,
680 
681 	.bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
682 	.bTerminalID = USB_IN_OT_ID,
683 	.wTerminalType = cpu_to_le16(UAC_TERMINAL_STREAMING),
684 	.bAssocTerminal = 0,
685 	.bSourceID = IO_IN_IT_ID,
686 	.bCSourceID = USB_IN_CLK_ID,
687 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
688 };
689 
690 /* Ouput Terminal for I/O-Out */
691 static struct uac2_output_terminal_descriptor io_out_ot_desc = {
692 	.bLength = sizeof io_out_ot_desc,
693 	.bDescriptorType = USB_DT_CS_INTERFACE,
694 
695 	.bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
696 	.bTerminalID = IO_OUT_OT_ID,
697 	.wTerminalType = cpu_to_le16(UAC_OUTPUT_TERMINAL_UNDEFINED),
698 	.bAssocTerminal = 0,
699 	.bSourceID = USB_OUT_IT_ID,
700 	.bCSourceID = USB_OUT_CLK_ID,
701 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
702 };
703 
704 static struct uac2_ac_header_descriptor ac_hdr_desc = {
705 	.bLength = sizeof ac_hdr_desc,
706 	.bDescriptorType = USB_DT_CS_INTERFACE,
707 
708 	.bDescriptorSubtype = UAC_MS_HEADER,
709 	.bcdADC = cpu_to_le16(0x200),
710 	.bCategory = UAC2_FUNCTION_IO_BOX,
711 	.wTotalLength = sizeof in_clk_src_desc + sizeof out_clk_src_desc
712 			 + sizeof usb_out_it_desc + sizeof io_in_it_desc
713 			+ sizeof usb_in_ot_desc + sizeof io_out_ot_desc,
714 	.bmControls = 0,
715 };
716 
717 /* Audio Streaming OUT Interface - Alt0 */
718 static struct usb_interface_descriptor std_as_out_if0_desc = {
719 	.bLength = sizeof std_as_out_if0_desc,
720 	.bDescriptorType = USB_DT_INTERFACE,
721 
722 	.bAlternateSetting = 0,
723 	.bNumEndpoints = 0,
724 	.bInterfaceClass = USB_CLASS_AUDIO,
725 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
726 	.bInterfaceProtocol = UAC_VERSION_2,
727 };
728 
729 /* Audio Streaming OUT Interface - Alt1 */
730 static struct usb_interface_descriptor std_as_out_if1_desc = {
731 	.bLength = sizeof std_as_out_if1_desc,
732 	.bDescriptorType = USB_DT_INTERFACE,
733 
734 	.bAlternateSetting = 1,
735 	.bNumEndpoints = 1,
736 	.bInterfaceClass = USB_CLASS_AUDIO,
737 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
738 	.bInterfaceProtocol = UAC_VERSION_2,
739 };
740 
741 /* Audio Stream OUT Intface Desc */
742 static struct uac2_as_header_descriptor as_out_hdr_desc = {
743 	.bLength = sizeof as_out_hdr_desc,
744 	.bDescriptorType = USB_DT_CS_INTERFACE,
745 
746 	.bDescriptorSubtype = UAC_AS_GENERAL,
747 	.bTerminalLink = USB_OUT_IT_ID,
748 	.bmControls = 0,
749 	.bFormatType = UAC_FORMAT_TYPE_I,
750 	.bmFormats = cpu_to_le32(UAC_FORMAT_TYPE_I_PCM),
751 	.iChannelNames = 0,
752 };
753 
754 /* Audio USB_OUT Format */
755 static struct uac2_format_type_i_descriptor as_out_fmt1_desc = {
756 	.bLength = sizeof as_out_fmt1_desc,
757 	.bDescriptorType = USB_DT_CS_INTERFACE,
758 	.bDescriptorSubtype = UAC_FORMAT_TYPE,
759 	.bFormatType = UAC_FORMAT_TYPE_I,
760 };
761 
762 /* STD AS ISO OUT Endpoint */
763 static struct usb_endpoint_descriptor fs_epout_desc = {
764 	.bLength = USB_DT_ENDPOINT_SIZE,
765 	.bDescriptorType = USB_DT_ENDPOINT,
766 
767 	.bEndpointAddress = USB_DIR_OUT,
768 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
769 	.wMaxPacketSize = cpu_to_le16(1023),
770 	.bInterval = 1,
771 };
772 
773 static struct usb_endpoint_descriptor hs_epout_desc = {
774 	.bLength = USB_DT_ENDPOINT_SIZE,
775 	.bDescriptorType = USB_DT_ENDPOINT,
776 
777 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
778 	.wMaxPacketSize = cpu_to_le16(1024),
779 	.bInterval = 4,
780 };
781 
782 /* CS AS ISO OUT Endpoint */
783 static struct uac2_iso_endpoint_descriptor as_iso_out_desc = {
784 	.bLength = sizeof as_iso_out_desc,
785 	.bDescriptorType = USB_DT_CS_ENDPOINT,
786 
787 	.bDescriptorSubtype = UAC_EP_GENERAL,
788 	.bmAttributes = 0,
789 	.bmControls = 0,
790 	.bLockDelayUnits = 0,
791 	.wLockDelay = 0,
792 };
793 
794 /* Audio Streaming IN Interface - Alt0 */
795 static struct usb_interface_descriptor std_as_in_if0_desc = {
796 	.bLength = sizeof std_as_in_if0_desc,
797 	.bDescriptorType = USB_DT_INTERFACE,
798 
799 	.bAlternateSetting = 0,
800 	.bNumEndpoints = 0,
801 	.bInterfaceClass = USB_CLASS_AUDIO,
802 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
803 	.bInterfaceProtocol = UAC_VERSION_2,
804 };
805 
806 /* Audio Streaming IN Interface - Alt1 */
807 static struct usb_interface_descriptor std_as_in_if1_desc = {
808 	.bLength = sizeof std_as_in_if1_desc,
809 	.bDescriptorType = USB_DT_INTERFACE,
810 
811 	.bAlternateSetting = 1,
812 	.bNumEndpoints = 1,
813 	.bInterfaceClass = USB_CLASS_AUDIO,
814 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
815 	.bInterfaceProtocol = UAC_VERSION_2,
816 };
817 
818 /* Audio Stream IN Intface Desc */
819 static struct uac2_as_header_descriptor as_in_hdr_desc = {
820 	.bLength = sizeof as_in_hdr_desc,
821 	.bDescriptorType = USB_DT_CS_INTERFACE,
822 
823 	.bDescriptorSubtype = UAC_AS_GENERAL,
824 	.bTerminalLink = USB_IN_OT_ID,
825 	.bmControls = 0,
826 	.bFormatType = UAC_FORMAT_TYPE_I,
827 	.bmFormats = cpu_to_le32(UAC_FORMAT_TYPE_I_PCM),
828 	.iChannelNames = 0,
829 };
830 
831 /* Audio USB_IN Format */
832 static struct uac2_format_type_i_descriptor as_in_fmt1_desc = {
833 	.bLength = sizeof as_in_fmt1_desc,
834 	.bDescriptorType = USB_DT_CS_INTERFACE,
835 	.bDescriptorSubtype = UAC_FORMAT_TYPE,
836 	.bFormatType = UAC_FORMAT_TYPE_I,
837 };
838 
839 /* STD AS ISO IN Endpoint */
840 static struct usb_endpoint_descriptor fs_epin_desc = {
841 	.bLength = USB_DT_ENDPOINT_SIZE,
842 	.bDescriptorType = USB_DT_ENDPOINT,
843 
844 	.bEndpointAddress = USB_DIR_IN,
845 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
846 	.wMaxPacketSize = cpu_to_le16(1023),
847 	.bInterval = 1,
848 };
849 
850 static struct usb_endpoint_descriptor hs_epin_desc = {
851 	.bLength = USB_DT_ENDPOINT_SIZE,
852 	.bDescriptorType = USB_DT_ENDPOINT,
853 
854 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
855 	.wMaxPacketSize = cpu_to_le16(1024),
856 	.bInterval = 4,
857 };
858 
859 /* CS AS ISO IN Endpoint */
860 static struct uac2_iso_endpoint_descriptor as_iso_in_desc = {
861 	.bLength = sizeof as_iso_in_desc,
862 	.bDescriptorType = USB_DT_CS_ENDPOINT,
863 
864 	.bDescriptorSubtype = UAC_EP_GENERAL,
865 	.bmAttributes = 0,
866 	.bmControls = 0,
867 	.bLockDelayUnits = 0,
868 	.wLockDelay = 0,
869 };
870 
871 static struct usb_descriptor_header *fs_audio_desc[] = {
872 	(struct usb_descriptor_header *)&iad_desc,
873 	(struct usb_descriptor_header *)&std_ac_if_desc,
874 
875 	(struct usb_descriptor_header *)&ac_hdr_desc,
876 	(struct usb_descriptor_header *)&in_clk_src_desc,
877 	(struct usb_descriptor_header *)&out_clk_src_desc,
878 	(struct usb_descriptor_header *)&usb_out_it_desc,
879 	(struct usb_descriptor_header *)&io_in_it_desc,
880 	(struct usb_descriptor_header *)&usb_in_ot_desc,
881 	(struct usb_descriptor_header *)&io_out_ot_desc,
882 
883 	(struct usb_descriptor_header *)&std_as_out_if0_desc,
884 	(struct usb_descriptor_header *)&std_as_out_if1_desc,
885 
886 	(struct usb_descriptor_header *)&as_out_hdr_desc,
887 	(struct usb_descriptor_header *)&as_out_fmt1_desc,
888 	(struct usb_descriptor_header *)&fs_epout_desc,
889 	(struct usb_descriptor_header *)&as_iso_out_desc,
890 
891 	(struct usb_descriptor_header *)&std_as_in_if0_desc,
892 	(struct usb_descriptor_header *)&std_as_in_if1_desc,
893 
894 	(struct usb_descriptor_header *)&as_in_hdr_desc,
895 	(struct usb_descriptor_header *)&as_in_fmt1_desc,
896 	(struct usb_descriptor_header *)&fs_epin_desc,
897 	(struct usb_descriptor_header *)&as_iso_in_desc,
898 	NULL,
899 };
900 
901 static struct usb_descriptor_header *hs_audio_desc[] = {
902 	(struct usb_descriptor_header *)&iad_desc,
903 	(struct usb_descriptor_header *)&std_ac_if_desc,
904 
905 	(struct usb_descriptor_header *)&ac_hdr_desc,
906 	(struct usb_descriptor_header *)&in_clk_src_desc,
907 	(struct usb_descriptor_header *)&out_clk_src_desc,
908 	(struct usb_descriptor_header *)&usb_out_it_desc,
909 	(struct usb_descriptor_header *)&io_in_it_desc,
910 	(struct usb_descriptor_header *)&usb_in_ot_desc,
911 	(struct usb_descriptor_header *)&io_out_ot_desc,
912 
913 	(struct usb_descriptor_header *)&std_as_out_if0_desc,
914 	(struct usb_descriptor_header *)&std_as_out_if1_desc,
915 
916 	(struct usb_descriptor_header *)&as_out_hdr_desc,
917 	(struct usb_descriptor_header *)&as_out_fmt1_desc,
918 	(struct usb_descriptor_header *)&hs_epout_desc,
919 	(struct usb_descriptor_header *)&as_iso_out_desc,
920 
921 	(struct usb_descriptor_header *)&std_as_in_if0_desc,
922 	(struct usb_descriptor_header *)&std_as_in_if1_desc,
923 
924 	(struct usb_descriptor_header *)&as_in_hdr_desc,
925 	(struct usb_descriptor_header *)&as_in_fmt1_desc,
926 	(struct usb_descriptor_header *)&hs_epin_desc,
927 	(struct usb_descriptor_header *)&as_iso_in_desc,
928 	NULL,
929 };
930 
931 struct cntrl_cur_lay3 {
932 	__u32	dCUR;
933 };
934 
935 struct cntrl_range_lay3 {
936 	__u16	wNumSubRanges;
937 	__u32	dMIN;
938 	__u32	dMAX;
939 	__u32	dRES;
940 } __packed;
941 
942 static inline void
943 free_ep(struct uac2_rtd_params *prm, struct usb_ep *ep)
944 {
945 	struct snd_uac2_chip *uac2 = prm->uac2;
946 	int i;
947 
948 	if (!prm->ep_enabled)
949 		return;
950 
951 	prm->ep_enabled = false;
952 
953 	for (i = 0; i < USB_XFERS; i++) {
954 		if (prm->ureq[i].req) {
955 			usb_ep_dequeue(ep, prm->ureq[i].req);
956 			usb_ep_free_request(ep, prm->ureq[i].req);
957 			prm->ureq[i].req = NULL;
958 		}
959 	}
960 
961 	if (usb_ep_disable(ep))
962 		dev_err(&uac2->pdev.dev,
963 			"%s:%d Error!\n", __func__, __LINE__);
964 }
965 
966 static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
967 	struct usb_endpoint_descriptor *ep_desc,
968 	unsigned int factor, bool is_playback)
969 {
970 	int chmask, srate, ssize;
971 	u16 max_packet_size;
972 
973 	if (is_playback) {
974 		chmask = uac2_opts->p_chmask;
975 		srate = uac2_opts->p_srate;
976 		ssize = uac2_opts->p_ssize;
977 	} else {
978 		chmask = uac2_opts->c_chmask;
979 		srate = uac2_opts->c_srate;
980 		ssize = uac2_opts->c_ssize;
981 	}
982 
983 	max_packet_size = num_channels(chmask) * ssize *
984 		DIV_ROUND_UP(srate, factor / (1 << (ep_desc->bInterval - 1)));
985 	ep_desc->wMaxPacketSize = cpu_to_le16(min_t(u16, max_packet_size,
986 				le16_to_cpu(ep_desc->wMaxPacketSize)));
987 }
988 
989 static int
990 afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
991 {
992 	struct audio_dev *agdev = func_to_agdev(fn);
993 	struct snd_uac2_chip *uac2 = &agdev->uac2;
994 	struct usb_composite_dev *cdev = cfg->cdev;
995 	struct usb_gadget *gadget = cdev->gadget;
996 	struct device *dev = &uac2->pdev.dev;
997 	struct uac2_rtd_params *prm;
998 	struct f_uac2_opts *uac2_opts;
999 	struct usb_string *us;
1000 	int ret;
1001 
1002 	uac2_opts = container_of(fn->fi, struct f_uac2_opts, func_inst);
1003 
1004 	us = usb_gstrings_attach(cdev, fn_strings, ARRAY_SIZE(strings_fn));
1005 	if (IS_ERR(us))
1006 		return PTR_ERR(us);
1007 	iad_desc.iFunction = us[STR_ASSOC].id;
1008 	std_ac_if_desc.iInterface = us[STR_IF_CTRL].id;
1009 	in_clk_src_desc.iClockSource = us[STR_CLKSRC_IN].id;
1010 	out_clk_src_desc.iClockSource = us[STR_CLKSRC_OUT].id;
1011 	usb_out_it_desc.iTerminal = us[STR_USB_IT].id;
1012 	io_in_it_desc.iTerminal = us[STR_IO_IT].id;
1013 	usb_in_ot_desc.iTerminal = us[STR_USB_OT].id;
1014 	io_out_ot_desc.iTerminal = us[STR_IO_OT].id;
1015 	std_as_out_if0_desc.iInterface = us[STR_AS_OUT_ALT0].id;
1016 	std_as_out_if1_desc.iInterface = us[STR_AS_OUT_ALT1].id;
1017 	std_as_in_if0_desc.iInterface = us[STR_AS_IN_ALT0].id;
1018 	std_as_in_if1_desc.iInterface = us[STR_AS_IN_ALT1].id;
1019 
1020 
1021 	/* Initialize the configurable parameters */
1022 	usb_out_it_desc.bNrChannels = num_channels(uac2_opts->c_chmask);
1023 	usb_out_it_desc.bmChannelConfig = cpu_to_le32(uac2_opts->c_chmask);
1024 	io_in_it_desc.bNrChannels = num_channels(uac2_opts->p_chmask);
1025 	io_in_it_desc.bmChannelConfig = cpu_to_le32(uac2_opts->p_chmask);
1026 	as_out_hdr_desc.bNrChannels = num_channels(uac2_opts->c_chmask);
1027 	as_out_hdr_desc.bmChannelConfig = cpu_to_le32(uac2_opts->c_chmask);
1028 	as_in_hdr_desc.bNrChannels = num_channels(uac2_opts->p_chmask);
1029 	as_in_hdr_desc.bmChannelConfig = cpu_to_le32(uac2_opts->p_chmask);
1030 	as_out_fmt1_desc.bSubslotSize = uac2_opts->c_ssize;
1031 	as_out_fmt1_desc.bBitResolution = uac2_opts->c_ssize * 8;
1032 	as_in_fmt1_desc.bSubslotSize = uac2_opts->p_ssize;
1033 	as_in_fmt1_desc.bBitResolution = uac2_opts->p_ssize * 8;
1034 
1035 	snprintf(clksrc_in, sizeof(clksrc_in), "%uHz", uac2_opts->p_srate);
1036 	snprintf(clksrc_out, sizeof(clksrc_out), "%uHz", uac2_opts->c_srate);
1037 
1038 	ret = usb_interface_id(cfg, fn);
1039 	if (ret < 0) {
1040 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1041 		return ret;
1042 	}
1043 	std_ac_if_desc.bInterfaceNumber = ret;
1044 	agdev->ac_intf = ret;
1045 	agdev->ac_alt = 0;
1046 
1047 	ret = usb_interface_id(cfg, fn);
1048 	if (ret < 0) {
1049 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1050 		return ret;
1051 	}
1052 	std_as_out_if0_desc.bInterfaceNumber = ret;
1053 	std_as_out_if1_desc.bInterfaceNumber = ret;
1054 	agdev->as_out_intf = ret;
1055 	agdev->as_out_alt = 0;
1056 
1057 	ret = usb_interface_id(cfg, fn);
1058 	if (ret < 0) {
1059 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1060 		return ret;
1061 	}
1062 	std_as_in_if0_desc.bInterfaceNumber = ret;
1063 	std_as_in_if1_desc.bInterfaceNumber = ret;
1064 	agdev->as_in_intf = ret;
1065 	agdev->as_in_alt = 0;
1066 
1067 	agdev->out_ep = usb_ep_autoconfig(gadget, &fs_epout_desc);
1068 	if (!agdev->out_ep) {
1069 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1070 		goto err;
1071 	}
1072 
1073 	agdev->in_ep = usb_ep_autoconfig(gadget, &fs_epin_desc);
1074 	if (!agdev->in_ep) {
1075 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1076 		goto err;
1077 	}
1078 
1079 	uac2->p_prm.uac2 = uac2;
1080 	uac2->c_prm.uac2 = uac2;
1081 
1082 	/* Calculate wMaxPacketSize according to audio bandwidth */
1083 	set_ep_max_packet_size(uac2_opts, &fs_epin_desc, 1000, true);
1084 	set_ep_max_packet_size(uac2_opts, &fs_epout_desc, 1000, false);
1085 	set_ep_max_packet_size(uac2_opts, &hs_epin_desc, 8000, true);
1086 	set_ep_max_packet_size(uac2_opts, &hs_epout_desc, 8000, false);
1087 
1088 	hs_epout_desc.bEndpointAddress = fs_epout_desc.bEndpointAddress;
1089 	hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress;
1090 
1091 	ret = usb_assign_descriptors(fn, fs_audio_desc, hs_audio_desc, NULL,
1092 				     NULL);
1093 	if (ret)
1094 		goto err;
1095 
1096 	prm = &agdev->uac2.c_prm;
1097 	prm->max_psize = hs_epout_desc.wMaxPacketSize;
1098 	prm->rbuf = kzalloc(prm->max_psize * USB_XFERS, GFP_KERNEL);
1099 	if (!prm->rbuf) {
1100 		prm->max_psize = 0;
1101 		goto err_free_descs;
1102 	}
1103 
1104 	prm = &agdev->uac2.p_prm;
1105 	prm->max_psize = hs_epin_desc.wMaxPacketSize;
1106 	prm->rbuf = kzalloc(prm->max_psize * USB_XFERS, GFP_KERNEL);
1107 	if (!prm->rbuf) {
1108 		prm->max_psize = 0;
1109 		goto err_free_descs;
1110 	}
1111 
1112 	ret = alsa_uac2_init(agdev);
1113 	if (ret)
1114 		goto err_free_descs;
1115 	return 0;
1116 
1117 err_free_descs:
1118 	usb_free_all_descriptors(fn);
1119 err:
1120 	kfree(agdev->uac2.p_prm.rbuf);
1121 	kfree(agdev->uac2.c_prm.rbuf);
1122 	return -EINVAL;
1123 }
1124 
1125 static int
1126 afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt)
1127 {
1128 	struct usb_composite_dev *cdev = fn->config->cdev;
1129 	struct audio_dev *agdev = func_to_agdev(fn);
1130 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1131 	struct usb_gadget *gadget = cdev->gadget;
1132 	struct device *dev = &uac2->pdev.dev;
1133 	struct usb_request *req;
1134 	struct usb_ep *ep;
1135 	struct uac2_rtd_params *prm;
1136 	int req_len, i;
1137 
1138 	/* No i/f has more than 2 alt settings */
1139 	if (alt > 1) {
1140 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1141 		return -EINVAL;
1142 	}
1143 
1144 	if (intf == agdev->ac_intf) {
1145 		/* Control I/f has only 1 AltSetting - 0 */
1146 		if (alt) {
1147 			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1148 			return -EINVAL;
1149 		}
1150 		return 0;
1151 	}
1152 
1153 	if (intf == agdev->as_out_intf) {
1154 		ep = agdev->out_ep;
1155 		prm = &uac2->c_prm;
1156 		config_ep_by_speed(gadget, fn, ep);
1157 		agdev->as_out_alt = alt;
1158 		req_len = prm->max_psize;
1159 	} else if (intf == agdev->as_in_intf) {
1160 		struct f_uac2_opts *opts = agdev_to_uac2_opts(agdev);
1161 		unsigned int factor, rate;
1162 		struct usb_endpoint_descriptor *ep_desc;
1163 
1164 		ep = agdev->in_ep;
1165 		prm = &uac2->p_prm;
1166 		config_ep_by_speed(gadget, fn, ep);
1167 		agdev->as_in_alt = alt;
1168 
1169 		/* pre-calculate the playback endpoint's interval */
1170 		if (gadget->speed == USB_SPEED_FULL) {
1171 			ep_desc = &fs_epin_desc;
1172 			factor = 1000;
1173 		} else {
1174 			ep_desc = &hs_epin_desc;
1175 			factor = 8000;
1176 		}
1177 
1178 		/* pre-compute some values for iso_complete() */
1179 		uac2->p_framesize = opts->p_ssize *
1180 				    num_channels(opts->p_chmask);
1181 		rate = opts->p_srate * uac2->p_framesize;
1182 		uac2->p_interval = factor / (1 << (ep_desc->bInterval - 1));
1183 		uac2->p_pktsize = min_t(unsigned int, rate / uac2->p_interval,
1184 					prm->max_psize);
1185 
1186 		if (uac2->p_pktsize < prm->max_psize)
1187 			uac2->p_pktsize_residue = rate % uac2->p_interval;
1188 		else
1189 			uac2->p_pktsize_residue = 0;
1190 
1191 		req_len = uac2->p_pktsize;
1192 		uac2->p_residue = 0;
1193 	} else {
1194 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1195 		return -EINVAL;
1196 	}
1197 
1198 	if (alt == 0) {
1199 		free_ep(prm, ep);
1200 		return 0;
1201 	}
1202 
1203 	prm->ep_enabled = true;
1204 	usb_ep_enable(ep);
1205 
1206 	for (i = 0; i < USB_XFERS; i++) {
1207 		if (!prm->ureq[i].req) {
1208 			req = usb_ep_alloc_request(ep, GFP_ATOMIC);
1209 			if (req == NULL)
1210 				return -ENOMEM;
1211 
1212 			prm->ureq[i].req = req;
1213 			prm->ureq[i].pp = prm;
1214 
1215 			req->zero = 0;
1216 			req->context = &prm->ureq[i];
1217 			req->length = req_len;
1218 			req->complete = agdev_iso_complete;
1219 			req->buf = prm->rbuf + i * prm->max_psize;
1220 		}
1221 
1222 		if (usb_ep_queue(ep, prm->ureq[i].req, GFP_ATOMIC))
1223 			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1224 	}
1225 
1226 	return 0;
1227 }
1228 
1229 static int
1230 afunc_get_alt(struct usb_function *fn, unsigned intf)
1231 {
1232 	struct audio_dev *agdev = func_to_agdev(fn);
1233 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1234 
1235 	if (intf == agdev->ac_intf)
1236 		return agdev->ac_alt;
1237 	else if (intf == agdev->as_out_intf)
1238 		return agdev->as_out_alt;
1239 	else if (intf == agdev->as_in_intf)
1240 		return agdev->as_in_alt;
1241 	else
1242 		dev_err(&uac2->pdev.dev,
1243 			"%s:%d Invalid Interface %d!\n",
1244 			__func__, __LINE__, intf);
1245 
1246 	return -EINVAL;
1247 }
1248 
1249 static void
1250 afunc_disable(struct usb_function *fn)
1251 {
1252 	struct audio_dev *agdev = func_to_agdev(fn);
1253 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1254 
1255 	free_ep(&uac2->p_prm, agdev->in_ep);
1256 	agdev->as_in_alt = 0;
1257 
1258 	free_ep(&uac2->c_prm, agdev->out_ep);
1259 	agdev->as_out_alt = 0;
1260 }
1261 
1262 static int
1263 in_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1264 {
1265 	struct usb_request *req = fn->config->cdev->req;
1266 	struct audio_dev *agdev = func_to_agdev(fn);
1267 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1268 	struct f_uac2_opts *opts;
1269 	u16 w_length = le16_to_cpu(cr->wLength);
1270 	u16 w_index = le16_to_cpu(cr->wIndex);
1271 	u16 w_value = le16_to_cpu(cr->wValue);
1272 	u8 entity_id = (w_index >> 8) & 0xff;
1273 	u8 control_selector = w_value >> 8;
1274 	int value = -EOPNOTSUPP;
1275 	int p_srate, c_srate;
1276 
1277 	opts = agdev_to_uac2_opts(agdev);
1278 	p_srate = opts->p_srate;
1279 	c_srate = opts->c_srate;
1280 
1281 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
1282 		struct cntrl_cur_lay3 c;
1283 		memset(&c, 0, sizeof(struct cntrl_cur_lay3));
1284 
1285 		if (entity_id == USB_IN_CLK_ID)
1286 			c.dCUR = p_srate;
1287 		else if (entity_id == USB_OUT_CLK_ID)
1288 			c.dCUR = c_srate;
1289 
1290 		value = min_t(unsigned, w_length, sizeof c);
1291 		memcpy(req->buf, &c, value);
1292 	} else if (control_selector == UAC2_CS_CONTROL_CLOCK_VALID) {
1293 		*(u8 *)req->buf = 1;
1294 		value = min_t(unsigned, w_length, 1);
1295 	} else {
1296 		dev_err(&uac2->pdev.dev,
1297 			"%s:%d control_selector=%d TODO!\n",
1298 			__func__, __LINE__, control_selector);
1299 	}
1300 
1301 	return value;
1302 }
1303 
1304 static int
1305 in_rq_range(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1306 {
1307 	struct usb_request *req = fn->config->cdev->req;
1308 	struct audio_dev *agdev = func_to_agdev(fn);
1309 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1310 	struct f_uac2_opts *opts;
1311 	u16 w_length = le16_to_cpu(cr->wLength);
1312 	u16 w_index = le16_to_cpu(cr->wIndex);
1313 	u16 w_value = le16_to_cpu(cr->wValue);
1314 	u8 entity_id = (w_index >> 8) & 0xff;
1315 	u8 control_selector = w_value >> 8;
1316 	struct cntrl_range_lay3 r;
1317 	int value = -EOPNOTSUPP;
1318 	int p_srate, c_srate;
1319 
1320 	opts = agdev_to_uac2_opts(agdev);
1321 	p_srate = opts->p_srate;
1322 	c_srate = opts->c_srate;
1323 
1324 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
1325 		if (entity_id == USB_IN_CLK_ID)
1326 			r.dMIN = p_srate;
1327 		else if (entity_id == USB_OUT_CLK_ID)
1328 			r.dMIN = c_srate;
1329 		else
1330 			return -EOPNOTSUPP;
1331 
1332 		r.dMAX = r.dMIN;
1333 		r.dRES = 0;
1334 		r.wNumSubRanges = 1;
1335 
1336 		value = min_t(unsigned, w_length, sizeof r);
1337 		memcpy(req->buf, &r, value);
1338 	} else {
1339 		dev_err(&uac2->pdev.dev,
1340 			"%s:%d control_selector=%d TODO!\n",
1341 			__func__, __LINE__, control_selector);
1342 	}
1343 
1344 	return value;
1345 }
1346 
1347 static int
1348 ac_rq_in(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1349 {
1350 	if (cr->bRequest == UAC2_CS_CUR)
1351 		return in_rq_cur(fn, cr);
1352 	else if (cr->bRequest == UAC2_CS_RANGE)
1353 		return in_rq_range(fn, cr);
1354 	else
1355 		return -EOPNOTSUPP;
1356 }
1357 
1358 static int
1359 out_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1360 {
1361 	u16 w_length = le16_to_cpu(cr->wLength);
1362 	u16 w_value = le16_to_cpu(cr->wValue);
1363 	u8 control_selector = w_value >> 8;
1364 
1365 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ)
1366 		return w_length;
1367 
1368 	return -EOPNOTSUPP;
1369 }
1370 
1371 static int
1372 setup_rq_inf(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1373 {
1374 	struct audio_dev *agdev = func_to_agdev(fn);
1375 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1376 	u16 w_index = le16_to_cpu(cr->wIndex);
1377 	u8 intf = w_index & 0xff;
1378 
1379 	if (intf != agdev->ac_intf) {
1380 		dev_err(&uac2->pdev.dev,
1381 			"%s:%d Error!\n", __func__, __LINE__);
1382 		return -EOPNOTSUPP;
1383 	}
1384 
1385 	if (cr->bRequestType & USB_DIR_IN)
1386 		return ac_rq_in(fn, cr);
1387 	else if (cr->bRequest == UAC2_CS_CUR)
1388 		return out_rq_cur(fn, cr);
1389 
1390 	return -EOPNOTSUPP;
1391 }
1392 
1393 static int
1394 afunc_setup(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1395 {
1396 	struct usb_composite_dev *cdev = fn->config->cdev;
1397 	struct audio_dev *agdev = func_to_agdev(fn);
1398 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1399 	struct usb_request *req = cdev->req;
1400 	u16 w_length = le16_to_cpu(cr->wLength);
1401 	int value = -EOPNOTSUPP;
1402 
1403 	/* Only Class specific requests are supposed to reach here */
1404 	if ((cr->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
1405 		return -EOPNOTSUPP;
1406 
1407 	if ((cr->bRequestType & USB_RECIP_MASK) == USB_RECIP_INTERFACE)
1408 		value = setup_rq_inf(fn, cr);
1409 	else
1410 		dev_err(&uac2->pdev.dev, "%s:%d Error!\n", __func__, __LINE__);
1411 
1412 	if (value >= 0) {
1413 		req->length = value;
1414 		req->zero = value < w_length;
1415 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1416 		if (value < 0) {
1417 			dev_err(&uac2->pdev.dev,
1418 				"%s:%d Error!\n", __func__, __LINE__);
1419 			req->status = 0;
1420 		}
1421 	}
1422 
1423 	return value;
1424 }
1425 
1426 static inline struct f_uac2_opts *to_f_uac2_opts(struct config_item *item)
1427 {
1428 	return container_of(to_config_group(item), struct f_uac2_opts,
1429 			    func_inst.group);
1430 }
1431 
1432 static void f_uac2_attr_release(struct config_item *item)
1433 {
1434 	struct f_uac2_opts *opts = to_f_uac2_opts(item);
1435 
1436 	usb_put_function_instance(&opts->func_inst);
1437 }
1438 
1439 static struct configfs_item_operations f_uac2_item_ops = {
1440 	.release	= f_uac2_attr_release,
1441 };
1442 
1443 #define UAC2_ATTRIBUTE(name)						\
1444 static ssize_t f_uac2_opts_##name##_show(struct config_item *item,	\
1445 					 char *page)			\
1446 {									\
1447 	struct f_uac2_opts *opts = to_f_uac2_opts(item);		\
1448 	int result;							\
1449 									\
1450 	mutex_lock(&opts->lock);					\
1451 	result = sprintf(page, "%u\n", opts->name);			\
1452 	mutex_unlock(&opts->lock);					\
1453 									\
1454 	return result;							\
1455 }									\
1456 									\
1457 static ssize_t f_uac2_opts_##name##_store(struct config_item *item,	\
1458 					  const char *page, size_t len)	\
1459 {									\
1460 	struct f_uac2_opts *opts = to_f_uac2_opts(item);		\
1461 	int ret;							\
1462 	u32 num;							\
1463 									\
1464 	mutex_lock(&opts->lock);					\
1465 	if (opts->refcnt) {						\
1466 		ret = -EBUSY;						\
1467 		goto end;						\
1468 	}								\
1469 									\
1470 	ret = kstrtou32(page, 0, &num);					\
1471 	if (ret)							\
1472 		goto end;						\
1473 									\
1474 	opts->name = num;						\
1475 	ret = len;							\
1476 									\
1477 end:									\
1478 	mutex_unlock(&opts->lock);					\
1479 	return ret;							\
1480 }									\
1481 									\
1482 CONFIGFS_ATTR(f_uac2_opts_, name)
1483 
1484 UAC2_ATTRIBUTE(p_chmask);
1485 UAC2_ATTRIBUTE(p_srate);
1486 UAC2_ATTRIBUTE(p_ssize);
1487 UAC2_ATTRIBUTE(c_chmask);
1488 UAC2_ATTRIBUTE(c_srate);
1489 UAC2_ATTRIBUTE(c_ssize);
1490 
1491 static struct configfs_attribute *f_uac2_attrs[] = {
1492 	&f_uac2_opts_attr_p_chmask,
1493 	&f_uac2_opts_attr_p_srate,
1494 	&f_uac2_opts_attr_p_ssize,
1495 	&f_uac2_opts_attr_c_chmask,
1496 	&f_uac2_opts_attr_c_srate,
1497 	&f_uac2_opts_attr_c_ssize,
1498 	NULL,
1499 };
1500 
1501 static struct config_item_type f_uac2_func_type = {
1502 	.ct_item_ops	= &f_uac2_item_ops,
1503 	.ct_attrs	= f_uac2_attrs,
1504 	.ct_owner	= THIS_MODULE,
1505 };
1506 
1507 static void afunc_free_inst(struct usb_function_instance *f)
1508 {
1509 	struct f_uac2_opts *opts;
1510 
1511 	opts = container_of(f, struct f_uac2_opts, func_inst);
1512 	kfree(opts);
1513 }
1514 
1515 static struct usb_function_instance *afunc_alloc_inst(void)
1516 {
1517 	struct f_uac2_opts *opts;
1518 
1519 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1520 	if (!opts)
1521 		return ERR_PTR(-ENOMEM);
1522 
1523 	mutex_init(&opts->lock);
1524 	opts->func_inst.free_func_inst = afunc_free_inst;
1525 
1526 	config_group_init_type_name(&opts->func_inst.group, "",
1527 				    &f_uac2_func_type);
1528 
1529 	opts->p_chmask = UAC2_DEF_PCHMASK;
1530 	opts->p_srate = UAC2_DEF_PSRATE;
1531 	opts->p_ssize = UAC2_DEF_PSSIZE;
1532 	opts->c_chmask = UAC2_DEF_CCHMASK;
1533 	opts->c_srate = UAC2_DEF_CSRATE;
1534 	opts->c_ssize = UAC2_DEF_CSSIZE;
1535 	return &opts->func_inst;
1536 }
1537 
1538 static void afunc_free(struct usb_function *f)
1539 {
1540 	struct audio_dev *agdev;
1541 	struct f_uac2_opts *opts;
1542 
1543 	agdev = func_to_agdev(f);
1544 	opts = container_of(f->fi, struct f_uac2_opts, func_inst);
1545 	kfree(agdev);
1546 	mutex_lock(&opts->lock);
1547 	--opts->refcnt;
1548 	mutex_unlock(&opts->lock);
1549 }
1550 
1551 static void afunc_unbind(struct usb_configuration *c, struct usb_function *f)
1552 {
1553 	struct audio_dev *agdev = func_to_agdev(f);
1554 	struct uac2_rtd_params *prm;
1555 
1556 	alsa_uac2_exit(agdev);
1557 
1558 	prm = &agdev->uac2.p_prm;
1559 	kfree(prm->rbuf);
1560 
1561 	prm = &agdev->uac2.c_prm;
1562 	kfree(prm->rbuf);
1563 	usb_free_all_descriptors(f);
1564 }
1565 
1566 static struct usb_function *afunc_alloc(struct usb_function_instance *fi)
1567 {
1568 	struct audio_dev *agdev;
1569 	struct f_uac2_opts *opts;
1570 
1571 	agdev = kzalloc(sizeof(*agdev), GFP_KERNEL);
1572 	if (agdev == NULL)
1573 		return ERR_PTR(-ENOMEM);
1574 
1575 	opts = container_of(fi, struct f_uac2_opts, func_inst);
1576 	mutex_lock(&opts->lock);
1577 	++opts->refcnt;
1578 	mutex_unlock(&opts->lock);
1579 
1580 	agdev->func.name = "uac2_func";
1581 	agdev->func.bind = afunc_bind;
1582 	agdev->func.unbind = afunc_unbind;
1583 	agdev->func.set_alt = afunc_set_alt;
1584 	agdev->func.get_alt = afunc_get_alt;
1585 	agdev->func.disable = afunc_disable;
1586 	agdev->func.setup = afunc_setup;
1587 	agdev->func.free_func = afunc_free;
1588 
1589 	return &agdev->func;
1590 }
1591 
1592 DECLARE_USB_FUNCTION_INIT(uac2, afunc_alloc_inst, afunc_alloc);
1593 MODULE_LICENSE("GPL");
1594 MODULE_AUTHOR("Yadwinder Singh");
1595 MODULE_AUTHOR("Jaswinder Singh");
1596