xref: /linux/drivers/usb/gadget/function/f_uac2.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 /*
26  * The driver implements a simple UAC_2 topology.
27  * USB-OUT -> IT_1 -> OT_3 -> ALSA_Capture
28  * ALSA_Playback -> IT_2 -> OT_4 -> USB-IN
29  * Capture and Playback sampling rates are independently
30  *  controlled by two clock sources :
31  *    CLK_5 := c_srate, and CLK_6 := p_srate
32  */
33 #define USB_OUT_IT_ID	1
34 #define IO_IN_IT_ID	2
35 #define IO_OUT_OT_ID	3
36 #define USB_IN_OT_ID	4
37 #define USB_OUT_CLK_ID	5
38 #define USB_IN_CLK_ID	6
39 
40 #define CONTROL_ABSENT	0
41 #define CONTROL_RDONLY	1
42 #define CONTROL_RDWR	3
43 
44 #define CLK_FREQ_CTRL	0
45 #define CLK_VLD_CTRL	2
46 
47 #define COPY_CTRL	0
48 #define CONN_CTRL	2
49 #define OVRLD_CTRL	4
50 #define CLSTR_CTRL	6
51 #define UNFLW_CTRL	8
52 #define OVFLW_CTRL	10
53 
54 static const char *uac2_name = "snd_uac2";
55 
56 struct uac2_req {
57 	struct uac2_rtd_params *pp; /* parent param */
58 	struct usb_request *req;
59 };
60 
61 struct uac2_rtd_params {
62 	struct snd_uac2_chip *uac2; /* parent chip */
63 	bool ep_enabled; /* if the ep is enabled */
64 	/* Size of the ring buffer */
65 	size_t dma_bytes;
66 	unsigned char *dma_area;
67 
68 	struct snd_pcm_substream *ss;
69 
70 	/* Ring buffer */
71 	ssize_t hw_ptr;
72 
73 	void *rbuf;
74 
75 	size_t period_size;
76 
77 	unsigned max_psize;
78 	struct uac2_req *ureq;
79 
80 	spinlock_t lock;
81 };
82 
83 struct snd_uac2_chip {
84 	struct platform_device pdev;
85 	struct platform_driver pdrv;
86 
87 	struct uac2_rtd_params p_prm;
88 	struct uac2_rtd_params c_prm;
89 
90 	struct snd_card *card;
91 	struct snd_pcm *pcm;
92 
93 	/* timekeeping for the playback endpoint */
94 	unsigned int p_interval;
95 	unsigned int p_residue;
96 
97 	/* pre-calculated values for playback iso completion */
98 	unsigned int p_pktsize;
99 	unsigned int p_pktsize_residue;
100 	unsigned int p_framesize;
101 };
102 
103 #define BUFF_SIZE_MAX	(PAGE_SIZE * 16)
104 #define PRD_SIZE_MAX	PAGE_SIZE
105 #define MIN_PERIODS	4
106 
107 static struct snd_pcm_hardware uac2_pcm_hardware = {
108 	.info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER
109 		 | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID
110 		 | SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME,
111 	.rates = SNDRV_PCM_RATE_CONTINUOUS,
112 	.periods_max = BUFF_SIZE_MAX / PRD_SIZE_MAX,
113 	.buffer_bytes_max = BUFF_SIZE_MAX,
114 	.period_bytes_max = PRD_SIZE_MAX,
115 	.periods_min = MIN_PERIODS,
116 };
117 
118 struct audio_dev {
119 	u8 ac_intf, ac_alt;
120 	u8 as_out_intf, as_out_alt;
121 	u8 as_in_intf, as_in_alt;
122 
123 	struct usb_ep *in_ep, *out_ep;
124 	struct usb_function func;
125 
126 	/* The ALSA Sound Card it represents on the USB-Client side */
127 	struct snd_uac2_chip uac2;
128 };
129 
130 static inline
131 struct audio_dev *func_to_agdev(struct usb_function *f)
132 {
133 	return container_of(f, struct audio_dev, func);
134 }
135 
136 static inline
137 struct audio_dev *uac2_to_agdev(struct snd_uac2_chip *u)
138 {
139 	return container_of(u, struct audio_dev, uac2);
140 }
141 
142 static inline
143 struct snd_uac2_chip *pdev_to_uac2(struct platform_device *p)
144 {
145 	return container_of(p, struct snd_uac2_chip, pdev);
146 }
147 
148 static inline
149 struct f_uac2_opts *agdev_to_uac2_opts(struct audio_dev *agdev)
150 {
151 	return container_of(agdev->func.fi, struct f_uac2_opts, func_inst);
152 }
153 
154 static inline
155 uint num_channels(uint chanmask)
156 {
157 	uint num = 0;
158 
159 	while (chanmask) {
160 		num += (chanmask & 1);
161 		chanmask >>= 1;
162 	}
163 
164 	return num;
165 }
166 
167 static void
168 agdev_iso_complete(struct usb_ep *ep, struct usb_request *req)
169 {
170 	unsigned pending;
171 	unsigned long flags;
172 	unsigned int hw_ptr;
173 	bool update_alsa = false;
174 	int status = req->status;
175 	struct uac2_req *ur = req->context;
176 	struct snd_pcm_substream *substream;
177 	struct uac2_rtd_params *prm = ur->pp;
178 	struct snd_uac2_chip *uac2 = prm->uac2;
179 
180 	/* i/f shutting down */
181 	if (!prm->ep_enabled || req->status == -ESHUTDOWN)
182 		return;
183 
184 	/*
185 	 * We can't really do much about bad xfers.
186 	 * Afterall, the ISOCH xfers could fail legitimately.
187 	 */
188 	if (status)
189 		pr_debug("%s: iso_complete status(%d) %d/%d\n",
190 			__func__, status, req->actual, req->length);
191 
192 	substream = prm->ss;
193 
194 	/* Do nothing if ALSA isn't active */
195 	if (!substream)
196 		goto exit;
197 
198 	spin_lock_irqsave(&prm->lock, flags);
199 
200 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
201 		/*
202 		 * For each IN packet, take the quotient of the current data
203 		 * rate and the endpoint's interval as the base packet size.
204 		 * If there is a residue from this division, add it to the
205 		 * residue accumulator.
206 		 */
207 		req->length = uac2->p_pktsize;
208 		uac2->p_residue += uac2->p_pktsize_residue;
209 
210 		/*
211 		 * Whenever there are more bytes in the accumulator than we
212 		 * need to add one more sample frame, increase this packet's
213 		 * size and decrease the accumulator.
214 		 */
215 		if (uac2->p_residue / uac2->p_interval >= uac2->p_framesize) {
216 			req->length += uac2->p_framesize;
217 			uac2->p_residue -= uac2->p_framesize *
218 					   uac2->p_interval;
219 		}
220 
221 		req->actual = req->length;
222 	}
223 
224 	pending = prm->hw_ptr % prm->period_size;
225 	pending += req->actual;
226 	if (pending >= prm->period_size)
227 		update_alsa = true;
228 
229 	hw_ptr = prm->hw_ptr;
230 	prm->hw_ptr = (prm->hw_ptr + req->actual) % prm->dma_bytes;
231 
232 	spin_unlock_irqrestore(&prm->lock, flags);
233 
234 	/* Pack USB load in ALSA ring buffer */
235 	pending = prm->dma_bytes - hw_ptr;
236 
237 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
238 		if (unlikely(pending < req->actual)) {
239 			memcpy(req->buf, prm->dma_area + hw_ptr, pending);
240 			memcpy(req->buf + pending, prm->dma_area,
241 			       req->actual - pending);
242 		} else {
243 			memcpy(req->buf, prm->dma_area + hw_ptr, req->actual);
244 		}
245 	} else {
246 		if (unlikely(pending < req->actual)) {
247 			memcpy(prm->dma_area + hw_ptr, req->buf, pending);
248 			memcpy(prm->dma_area, req->buf + pending,
249 			       req->actual - pending);
250 		} else {
251 			memcpy(prm->dma_area + hw_ptr, req->buf, req->actual);
252 		}
253 	}
254 
255 exit:
256 	if (usb_ep_queue(ep, req, GFP_ATOMIC))
257 		dev_err(&uac2->pdev.dev, "%d Error!\n", __LINE__);
258 
259 	if (update_alsa)
260 		snd_pcm_period_elapsed(substream);
261 
262 	return;
263 }
264 
265 static int
266 uac2_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
267 {
268 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
269 	struct audio_dev *agdev = uac2_to_agdev(uac2);
270 	struct f_uac2_opts *uac2_opts = agdev_to_uac2_opts(agdev);
271 	struct uac2_rtd_params *prm;
272 	unsigned long flags;
273 	int err = 0;
274 
275 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
276 		prm = &uac2->p_prm;
277 	else
278 		prm = &uac2->c_prm;
279 
280 	spin_lock_irqsave(&prm->lock, flags);
281 
282 	/* Reset */
283 	prm->hw_ptr = 0;
284 
285 	switch (cmd) {
286 	case SNDRV_PCM_TRIGGER_START:
287 	case SNDRV_PCM_TRIGGER_RESUME:
288 		prm->ss = substream;
289 		break;
290 	case SNDRV_PCM_TRIGGER_STOP:
291 	case SNDRV_PCM_TRIGGER_SUSPEND:
292 		prm->ss = NULL;
293 		break;
294 	default:
295 		err = -EINVAL;
296 	}
297 
298 	spin_unlock_irqrestore(&prm->lock, flags);
299 
300 	/* Clear buffer after Play stops */
301 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && !prm->ss)
302 		memset(prm->rbuf, 0, prm->max_psize * uac2_opts->req_number);
303 
304 	return err;
305 }
306 
307 static snd_pcm_uframes_t uac2_pcm_pointer(struct snd_pcm_substream *substream)
308 {
309 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
310 	struct uac2_rtd_params *prm;
311 
312 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
313 		prm = &uac2->p_prm;
314 	else
315 		prm = &uac2->c_prm;
316 
317 	return bytes_to_frames(substream->runtime, prm->hw_ptr);
318 }
319 
320 static int uac2_pcm_hw_params(struct snd_pcm_substream *substream,
321 			       struct snd_pcm_hw_params *hw_params)
322 {
323 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
324 	struct uac2_rtd_params *prm;
325 	int err;
326 
327 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
328 		prm = &uac2->p_prm;
329 	else
330 		prm = &uac2->c_prm;
331 
332 	err = snd_pcm_lib_malloc_pages(substream,
333 					params_buffer_bytes(hw_params));
334 	if (err >= 0) {
335 		prm->dma_bytes = substream->runtime->dma_bytes;
336 		prm->dma_area = substream->runtime->dma_area;
337 		prm->period_size = params_period_bytes(hw_params);
338 	}
339 
340 	return err;
341 }
342 
343 static int uac2_pcm_hw_free(struct snd_pcm_substream *substream)
344 {
345 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
346 	struct uac2_rtd_params *prm;
347 
348 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
349 		prm = &uac2->p_prm;
350 	else
351 		prm = &uac2->c_prm;
352 
353 	prm->dma_area = NULL;
354 	prm->dma_bytes = 0;
355 	prm->period_size = 0;
356 
357 	return snd_pcm_lib_free_pages(substream);
358 }
359 
360 static int uac2_pcm_open(struct snd_pcm_substream *substream)
361 {
362 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
363 	struct snd_pcm_runtime *runtime = substream->runtime;
364 	struct audio_dev *audio_dev;
365 	struct f_uac2_opts *opts;
366 	int p_ssize, c_ssize;
367 	int p_srate, c_srate;
368 	int p_chmask, c_chmask;
369 
370 	audio_dev = uac2_to_agdev(uac2);
371 	opts = container_of(audio_dev->func.fi, struct f_uac2_opts, func_inst);
372 	p_ssize = opts->p_ssize;
373 	c_ssize = opts->c_ssize;
374 	p_srate = opts->p_srate;
375 	c_srate = opts->c_srate;
376 	p_chmask = opts->p_chmask;
377 	c_chmask = opts->c_chmask;
378 	uac2->p_residue = 0;
379 
380 	runtime->hw = uac2_pcm_hardware;
381 
382 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
383 		spin_lock_init(&uac2->p_prm.lock);
384 		runtime->hw.rate_min = p_srate;
385 		switch (p_ssize) {
386 		case 3:
387 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S24_3LE;
388 			break;
389 		case 4:
390 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S32_LE;
391 			break;
392 		default:
393 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S16_LE;
394 			break;
395 		}
396 		runtime->hw.channels_min = num_channels(p_chmask);
397 		runtime->hw.period_bytes_min = 2 * uac2->p_prm.max_psize
398 						/ runtime->hw.periods_min;
399 	} else {
400 		spin_lock_init(&uac2->c_prm.lock);
401 		runtime->hw.rate_min = c_srate;
402 		switch (c_ssize) {
403 		case 3:
404 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S24_3LE;
405 			break;
406 		case 4:
407 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S32_LE;
408 			break;
409 		default:
410 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S16_LE;
411 			break;
412 		}
413 		runtime->hw.channels_min = num_channels(c_chmask);
414 		runtime->hw.period_bytes_min = 2 * uac2->c_prm.max_psize
415 						/ runtime->hw.periods_min;
416 	}
417 
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 uac2_pcm_null(struct snd_pcm_substream *substream)
428 {
429 	return 0;
430 }
431 
432 static struct snd_pcm_ops uac2_pcm_ops = {
433 	.open = uac2_pcm_open,
434 	.close = uac2_pcm_null,
435 	.ioctl = snd_pcm_lib_ioctl,
436 	.hw_params = uac2_pcm_hw_params,
437 	.hw_free = uac2_pcm_hw_free,
438 	.trigger = uac2_pcm_trigger,
439 	.pointer = uac2_pcm_pointer,
440 	.prepare = uac2_pcm_null,
441 };
442 
443 static int snd_uac2_probe(struct platform_device *pdev)
444 {
445 	struct snd_uac2_chip *uac2 = pdev_to_uac2(pdev);
446 	struct snd_card *card;
447 	struct snd_pcm *pcm;
448 	struct audio_dev *audio_dev;
449 	struct f_uac2_opts *opts;
450 	int err;
451 	int p_chmask, c_chmask;
452 
453 	audio_dev = uac2_to_agdev(uac2);
454 	opts = container_of(audio_dev->func.fi, struct f_uac2_opts, func_inst);
455 	p_chmask = opts->p_chmask;
456 	c_chmask = opts->c_chmask;
457 
458 	/* Choose any slot, with no id */
459 	err = snd_card_new(&pdev->dev, -1, NULL, THIS_MODULE, 0, &card);
460 	if (err < 0)
461 		return err;
462 
463 	uac2->card = card;
464 
465 	/*
466 	 * Create first PCM device
467 	 * Create a substream only for non-zero channel streams
468 	 */
469 	err = snd_pcm_new(uac2->card, "UAC2 PCM", 0,
470 			       p_chmask ? 1 : 0, c_chmask ? 1 : 0, &pcm);
471 	if (err < 0)
472 		goto snd_fail;
473 
474 	strcpy(pcm->name, "UAC2 PCM");
475 	pcm->private_data = uac2;
476 
477 	uac2->pcm = pcm;
478 
479 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &uac2_pcm_ops);
480 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &uac2_pcm_ops);
481 
482 	strcpy(card->driver, "UAC2_Gadget");
483 	strcpy(card->shortname, "UAC2_Gadget");
484 	sprintf(card->longname, "UAC2_Gadget %i", pdev->id);
485 
486 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
487 		snd_dma_continuous_data(GFP_KERNEL), 0, BUFF_SIZE_MAX);
488 
489 	err = snd_card_register(card);
490 	if (!err) {
491 		platform_set_drvdata(pdev, card);
492 		return 0;
493 	}
494 
495 snd_fail:
496 	snd_card_free(card);
497 
498 	uac2->pcm = NULL;
499 	uac2->card = NULL;
500 
501 	return err;
502 }
503 
504 static int snd_uac2_remove(struct platform_device *pdev)
505 {
506 	struct snd_card *card = platform_get_drvdata(pdev);
507 
508 	if (card)
509 		return snd_card_free(card);
510 
511 	return 0;
512 }
513 
514 static void snd_uac2_release(struct device *dev)
515 {
516 	dev_dbg(dev, "releasing '%s'\n", dev_name(dev));
517 }
518 
519 static int alsa_uac2_init(struct audio_dev *agdev)
520 {
521 	struct snd_uac2_chip *uac2 = &agdev->uac2;
522 	int err;
523 
524 	uac2->pdrv.probe = snd_uac2_probe;
525 	uac2->pdrv.remove = snd_uac2_remove;
526 	uac2->pdrv.driver.name = uac2_name;
527 
528 	uac2->pdev.id = 0;
529 	uac2->pdev.name = uac2_name;
530 	uac2->pdev.dev.release = snd_uac2_release;
531 
532 	/* Register snd_uac2 driver */
533 	err = platform_driver_register(&uac2->pdrv);
534 	if (err)
535 		return err;
536 
537 	/* Register snd_uac2 device */
538 	err = platform_device_register(&uac2->pdev);
539 	if (err)
540 		platform_driver_unregister(&uac2->pdrv);
541 
542 	return err;
543 }
544 
545 static void alsa_uac2_exit(struct audio_dev *agdev)
546 {
547 	struct snd_uac2_chip *uac2 = &agdev->uac2;
548 
549 	platform_driver_unregister(&uac2->pdrv);
550 	platform_device_unregister(&uac2->pdev);
551 }
552 
553 
554 /* --------- USB Function Interface ------------- */
555 
556 enum {
557 	STR_ASSOC,
558 	STR_IF_CTRL,
559 	STR_CLKSRC_IN,
560 	STR_CLKSRC_OUT,
561 	STR_USB_IT,
562 	STR_IO_IT,
563 	STR_USB_OT,
564 	STR_IO_OT,
565 	STR_AS_OUT_ALT0,
566 	STR_AS_OUT_ALT1,
567 	STR_AS_IN_ALT0,
568 	STR_AS_IN_ALT1,
569 };
570 
571 static char clksrc_in[8];
572 static char clksrc_out[8];
573 
574 static struct usb_string strings_fn[] = {
575 	[STR_ASSOC].s = "Source/Sink",
576 	[STR_IF_CTRL].s = "Topology Control",
577 	[STR_CLKSRC_IN].s = clksrc_in,
578 	[STR_CLKSRC_OUT].s = clksrc_out,
579 	[STR_USB_IT].s = "USBH Out",
580 	[STR_IO_IT].s = "USBD Out",
581 	[STR_USB_OT].s = "USBH In",
582 	[STR_IO_OT].s = "USBD In",
583 	[STR_AS_OUT_ALT0].s = "Playback Inactive",
584 	[STR_AS_OUT_ALT1].s = "Playback Active",
585 	[STR_AS_IN_ALT0].s = "Capture Inactive",
586 	[STR_AS_IN_ALT1].s = "Capture Active",
587 	{ },
588 };
589 
590 static struct usb_gadget_strings str_fn = {
591 	.language = 0x0409,	/* en-us */
592 	.strings = strings_fn,
593 };
594 
595 static struct usb_gadget_strings *fn_strings[] = {
596 	&str_fn,
597 	NULL,
598 };
599 
600 static struct usb_interface_assoc_descriptor iad_desc = {
601 	.bLength = sizeof iad_desc,
602 	.bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
603 
604 	.bFirstInterface = 0,
605 	.bInterfaceCount = 3,
606 	.bFunctionClass = USB_CLASS_AUDIO,
607 	.bFunctionSubClass = UAC2_FUNCTION_SUBCLASS_UNDEFINED,
608 	.bFunctionProtocol = UAC_VERSION_2,
609 };
610 
611 /* Audio Control Interface */
612 static struct usb_interface_descriptor std_ac_if_desc = {
613 	.bLength = sizeof std_ac_if_desc,
614 	.bDescriptorType = USB_DT_INTERFACE,
615 
616 	.bAlternateSetting = 0,
617 	.bNumEndpoints = 0,
618 	.bInterfaceClass = USB_CLASS_AUDIO,
619 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL,
620 	.bInterfaceProtocol = UAC_VERSION_2,
621 };
622 
623 /* Clock source for IN traffic */
624 static struct uac_clock_source_descriptor in_clk_src_desc = {
625 	.bLength = sizeof in_clk_src_desc,
626 	.bDescriptorType = USB_DT_CS_INTERFACE,
627 
628 	.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
629 	.bClockID = USB_IN_CLK_ID,
630 	.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
631 	.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
632 	.bAssocTerminal = 0,
633 };
634 
635 /* Clock source for OUT traffic */
636 static struct uac_clock_source_descriptor out_clk_src_desc = {
637 	.bLength = sizeof out_clk_src_desc,
638 	.bDescriptorType = USB_DT_CS_INTERFACE,
639 
640 	.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
641 	.bClockID = USB_OUT_CLK_ID,
642 	.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
643 	.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
644 	.bAssocTerminal = 0,
645 };
646 
647 /* Input Terminal for USB_OUT */
648 static struct uac2_input_terminal_descriptor usb_out_it_desc = {
649 	.bLength = sizeof usb_out_it_desc,
650 	.bDescriptorType = USB_DT_CS_INTERFACE,
651 
652 	.bDescriptorSubtype = UAC_INPUT_TERMINAL,
653 	.bTerminalID = USB_OUT_IT_ID,
654 	.wTerminalType = cpu_to_le16(UAC_TERMINAL_STREAMING),
655 	.bAssocTerminal = 0,
656 	.bCSourceID = USB_OUT_CLK_ID,
657 	.iChannelNames = 0,
658 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
659 };
660 
661 /* Input Terminal for I/O-In */
662 static struct uac2_input_terminal_descriptor io_in_it_desc = {
663 	.bLength = sizeof io_in_it_desc,
664 	.bDescriptorType = USB_DT_CS_INTERFACE,
665 
666 	.bDescriptorSubtype = UAC_INPUT_TERMINAL,
667 	.bTerminalID = IO_IN_IT_ID,
668 	.wTerminalType = cpu_to_le16(UAC_INPUT_TERMINAL_UNDEFINED),
669 	.bAssocTerminal = 0,
670 	.bCSourceID = USB_IN_CLK_ID,
671 	.iChannelNames = 0,
672 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
673 };
674 
675 /* Ouput Terminal for USB_IN */
676 static struct uac2_output_terminal_descriptor usb_in_ot_desc = {
677 	.bLength = sizeof usb_in_ot_desc,
678 	.bDescriptorType = USB_DT_CS_INTERFACE,
679 
680 	.bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
681 	.bTerminalID = USB_IN_OT_ID,
682 	.wTerminalType = cpu_to_le16(UAC_TERMINAL_STREAMING),
683 	.bAssocTerminal = 0,
684 	.bSourceID = IO_IN_IT_ID,
685 	.bCSourceID = USB_IN_CLK_ID,
686 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
687 };
688 
689 /* Ouput Terminal for I/O-Out */
690 static struct uac2_output_terminal_descriptor io_out_ot_desc = {
691 	.bLength = sizeof io_out_ot_desc,
692 	.bDescriptorType = USB_DT_CS_INTERFACE,
693 
694 	.bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
695 	.bTerminalID = IO_OUT_OT_ID,
696 	.wTerminalType = cpu_to_le16(UAC_OUTPUT_TERMINAL_UNDEFINED),
697 	.bAssocTerminal = 0,
698 	.bSourceID = USB_OUT_IT_ID,
699 	.bCSourceID = USB_OUT_CLK_ID,
700 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
701 };
702 
703 static struct uac2_ac_header_descriptor ac_hdr_desc = {
704 	.bLength = sizeof ac_hdr_desc,
705 	.bDescriptorType = USB_DT_CS_INTERFACE,
706 
707 	.bDescriptorSubtype = UAC_MS_HEADER,
708 	.bcdADC = cpu_to_le16(0x200),
709 	.bCategory = UAC2_FUNCTION_IO_BOX,
710 	.wTotalLength = sizeof in_clk_src_desc + sizeof out_clk_src_desc
711 			 + sizeof usb_out_it_desc + sizeof io_in_it_desc
712 			+ sizeof usb_in_ot_desc + sizeof io_out_ot_desc,
713 	.bmControls = 0,
714 };
715 
716 /* Audio Streaming OUT Interface - Alt0 */
717 static struct usb_interface_descriptor std_as_out_if0_desc = {
718 	.bLength = sizeof std_as_out_if0_desc,
719 	.bDescriptorType = USB_DT_INTERFACE,
720 
721 	.bAlternateSetting = 0,
722 	.bNumEndpoints = 0,
723 	.bInterfaceClass = USB_CLASS_AUDIO,
724 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
725 	.bInterfaceProtocol = UAC_VERSION_2,
726 };
727 
728 /* Audio Streaming OUT Interface - Alt1 */
729 static struct usb_interface_descriptor std_as_out_if1_desc = {
730 	.bLength = sizeof std_as_out_if1_desc,
731 	.bDescriptorType = USB_DT_INTERFACE,
732 
733 	.bAlternateSetting = 1,
734 	.bNumEndpoints = 1,
735 	.bInterfaceClass = USB_CLASS_AUDIO,
736 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
737 	.bInterfaceProtocol = UAC_VERSION_2,
738 };
739 
740 /* Audio Stream OUT Intface Desc */
741 static struct uac2_as_header_descriptor as_out_hdr_desc = {
742 	.bLength = sizeof as_out_hdr_desc,
743 	.bDescriptorType = USB_DT_CS_INTERFACE,
744 
745 	.bDescriptorSubtype = UAC_AS_GENERAL,
746 	.bTerminalLink = USB_OUT_IT_ID,
747 	.bmControls = 0,
748 	.bFormatType = UAC_FORMAT_TYPE_I,
749 	.bmFormats = cpu_to_le32(UAC_FORMAT_TYPE_I_PCM),
750 	.iChannelNames = 0,
751 };
752 
753 /* Audio USB_OUT Format */
754 static struct uac2_format_type_i_descriptor as_out_fmt1_desc = {
755 	.bLength = sizeof as_out_fmt1_desc,
756 	.bDescriptorType = USB_DT_CS_INTERFACE,
757 	.bDescriptorSubtype = UAC_FORMAT_TYPE,
758 	.bFormatType = UAC_FORMAT_TYPE_I,
759 };
760 
761 /* STD AS ISO OUT Endpoint */
762 static struct usb_endpoint_descriptor fs_epout_desc = {
763 	.bLength = USB_DT_ENDPOINT_SIZE,
764 	.bDescriptorType = USB_DT_ENDPOINT,
765 
766 	.bEndpointAddress = USB_DIR_OUT,
767 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
768 	.wMaxPacketSize = cpu_to_le16(1023),
769 	.bInterval = 1,
770 };
771 
772 static struct usb_endpoint_descriptor hs_epout_desc = {
773 	.bLength = USB_DT_ENDPOINT_SIZE,
774 	.bDescriptorType = USB_DT_ENDPOINT,
775 
776 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
777 	.wMaxPacketSize = cpu_to_le16(1024),
778 	.bInterval = 4,
779 };
780 
781 /* CS AS ISO OUT Endpoint */
782 static struct uac2_iso_endpoint_descriptor as_iso_out_desc = {
783 	.bLength = sizeof as_iso_out_desc,
784 	.bDescriptorType = USB_DT_CS_ENDPOINT,
785 
786 	.bDescriptorSubtype = UAC_EP_GENERAL,
787 	.bmAttributes = 0,
788 	.bmControls = 0,
789 	.bLockDelayUnits = 0,
790 	.wLockDelay = 0,
791 };
792 
793 /* Audio Streaming IN Interface - Alt0 */
794 static struct usb_interface_descriptor std_as_in_if0_desc = {
795 	.bLength = sizeof std_as_in_if0_desc,
796 	.bDescriptorType = USB_DT_INTERFACE,
797 
798 	.bAlternateSetting = 0,
799 	.bNumEndpoints = 0,
800 	.bInterfaceClass = USB_CLASS_AUDIO,
801 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
802 	.bInterfaceProtocol = UAC_VERSION_2,
803 };
804 
805 /* Audio Streaming IN Interface - Alt1 */
806 static struct usb_interface_descriptor std_as_in_if1_desc = {
807 	.bLength = sizeof std_as_in_if1_desc,
808 	.bDescriptorType = USB_DT_INTERFACE,
809 
810 	.bAlternateSetting = 1,
811 	.bNumEndpoints = 1,
812 	.bInterfaceClass = USB_CLASS_AUDIO,
813 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
814 	.bInterfaceProtocol = UAC_VERSION_2,
815 };
816 
817 /* Audio Stream IN Intface Desc */
818 static struct uac2_as_header_descriptor as_in_hdr_desc = {
819 	.bLength = sizeof as_in_hdr_desc,
820 	.bDescriptorType = USB_DT_CS_INTERFACE,
821 
822 	.bDescriptorSubtype = UAC_AS_GENERAL,
823 	.bTerminalLink = USB_IN_OT_ID,
824 	.bmControls = 0,
825 	.bFormatType = UAC_FORMAT_TYPE_I,
826 	.bmFormats = cpu_to_le32(UAC_FORMAT_TYPE_I_PCM),
827 	.iChannelNames = 0,
828 };
829 
830 /* Audio USB_IN Format */
831 static struct uac2_format_type_i_descriptor as_in_fmt1_desc = {
832 	.bLength = sizeof as_in_fmt1_desc,
833 	.bDescriptorType = USB_DT_CS_INTERFACE,
834 	.bDescriptorSubtype = UAC_FORMAT_TYPE,
835 	.bFormatType = UAC_FORMAT_TYPE_I,
836 };
837 
838 /* STD AS ISO IN Endpoint */
839 static struct usb_endpoint_descriptor fs_epin_desc = {
840 	.bLength = USB_DT_ENDPOINT_SIZE,
841 	.bDescriptorType = USB_DT_ENDPOINT,
842 
843 	.bEndpointAddress = USB_DIR_IN,
844 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
845 	.wMaxPacketSize = cpu_to_le16(1023),
846 	.bInterval = 1,
847 };
848 
849 static struct usb_endpoint_descriptor hs_epin_desc = {
850 	.bLength = USB_DT_ENDPOINT_SIZE,
851 	.bDescriptorType = USB_DT_ENDPOINT,
852 
853 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
854 	.wMaxPacketSize = cpu_to_le16(1024),
855 	.bInterval = 4,
856 };
857 
858 /* CS AS ISO IN Endpoint */
859 static struct uac2_iso_endpoint_descriptor as_iso_in_desc = {
860 	.bLength = sizeof as_iso_in_desc,
861 	.bDescriptorType = USB_DT_CS_ENDPOINT,
862 
863 	.bDescriptorSubtype = UAC_EP_GENERAL,
864 	.bmAttributes = 0,
865 	.bmControls = 0,
866 	.bLockDelayUnits = 0,
867 	.wLockDelay = 0,
868 };
869 
870 static struct usb_descriptor_header *fs_audio_desc[] = {
871 	(struct usb_descriptor_header *)&iad_desc,
872 	(struct usb_descriptor_header *)&std_ac_if_desc,
873 
874 	(struct usb_descriptor_header *)&ac_hdr_desc,
875 	(struct usb_descriptor_header *)&in_clk_src_desc,
876 	(struct usb_descriptor_header *)&out_clk_src_desc,
877 	(struct usb_descriptor_header *)&usb_out_it_desc,
878 	(struct usb_descriptor_header *)&io_in_it_desc,
879 	(struct usb_descriptor_header *)&usb_in_ot_desc,
880 	(struct usb_descriptor_header *)&io_out_ot_desc,
881 
882 	(struct usb_descriptor_header *)&std_as_out_if0_desc,
883 	(struct usb_descriptor_header *)&std_as_out_if1_desc,
884 
885 	(struct usb_descriptor_header *)&as_out_hdr_desc,
886 	(struct usb_descriptor_header *)&as_out_fmt1_desc,
887 	(struct usb_descriptor_header *)&fs_epout_desc,
888 	(struct usb_descriptor_header *)&as_iso_out_desc,
889 
890 	(struct usb_descriptor_header *)&std_as_in_if0_desc,
891 	(struct usb_descriptor_header *)&std_as_in_if1_desc,
892 
893 	(struct usb_descriptor_header *)&as_in_hdr_desc,
894 	(struct usb_descriptor_header *)&as_in_fmt1_desc,
895 	(struct usb_descriptor_header *)&fs_epin_desc,
896 	(struct usb_descriptor_header *)&as_iso_in_desc,
897 	NULL,
898 };
899 
900 static struct usb_descriptor_header *hs_audio_desc[] = {
901 	(struct usb_descriptor_header *)&iad_desc,
902 	(struct usb_descriptor_header *)&std_ac_if_desc,
903 
904 	(struct usb_descriptor_header *)&ac_hdr_desc,
905 	(struct usb_descriptor_header *)&in_clk_src_desc,
906 	(struct usb_descriptor_header *)&out_clk_src_desc,
907 	(struct usb_descriptor_header *)&usb_out_it_desc,
908 	(struct usb_descriptor_header *)&io_in_it_desc,
909 	(struct usb_descriptor_header *)&usb_in_ot_desc,
910 	(struct usb_descriptor_header *)&io_out_ot_desc,
911 
912 	(struct usb_descriptor_header *)&std_as_out_if0_desc,
913 	(struct usb_descriptor_header *)&std_as_out_if1_desc,
914 
915 	(struct usb_descriptor_header *)&as_out_hdr_desc,
916 	(struct usb_descriptor_header *)&as_out_fmt1_desc,
917 	(struct usb_descriptor_header *)&hs_epout_desc,
918 	(struct usb_descriptor_header *)&as_iso_out_desc,
919 
920 	(struct usb_descriptor_header *)&std_as_in_if0_desc,
921 	(struct usb_descriptor_header *)&std_as_in_if1_desc,
922 
923 	(struct usb_descriptor_header *)&as_in_hdr_desc,
924 	(struct usb_descriptor_header *)&as_in_fmt1_desc,
925 	(struct usb_descriptor_header *)&hs_epin_desc,
926 	(struct usb_descriptor_header *)&as_iso_in_desc,
927 	NULL,
928 };
929 
930 struct cntrl_cur_lay3 {
931 	__u32	dCUR;
932 };
933 
934 struct cntrl_range_lay3 {
935 	__u16	wNumSubRanges;
936 	__u32	dMIN;
937 	__u32	dMAX;
938 	__u32	dRES;
939 } __packed;
940 
941 static inline void
942 free_ep(struct uac2_rtd_params *prm, struct usb_ep *ep)
943 {
944 	struct snd_uac2_chip *uac2 = prm->uac2;
945 	struct audio_dev *agdev = uac2_to_agdev(uac2);
946 	struct f_uac2_opts *uac2_opts = agdev_to_uac2_opts(agdev);
947 	int i;
948 
949 	if (!prm->ep_enabled)
950 		return;
951 
952 	prm->ep_enabled = false;
953 
954 	for (i = 0; i < uac2_opts->req_number; i++) {
955 		if (prm->ureq[i].req) {
956 			usb_ep_dequeue(ep, prm->ureq[i].req);
957 			usb_ep_free_request(ep, prm->ureq[i].req);
958 			prm->ureq[i].req = NULL;
959 		}
960 	}
961 
962 	if (usb_ep_disable(ep))
963 		dev_err(&uac2->pdev.dev,
964 			"%s:%d Error!\n", __func__, __LINE__);
965 }
966 
967 static void set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
968 	struct usb_endpoint_descriptor *ep_desc,
969 	unsigned int factor, bool is_playback)
970 {
971 	int chmask, srate, ssize;
972 	u16 max_packet_size;
973 
974 	if (is_playback) {
975 		chmask = uac2_opts->p_chmask;
976 		srate = uac2_opts->p_srate;
977 		ssize = uac2_opts->p_ssize;
978 	} else {
979 		chmask = uac2_opts->c_chmask;
980 		srate = uac2_opts->c_srate;
981 		ssize = uac2_opts->c_ssize;
982 	}
983 
984 	max_packet_size = num_channels(chmask) * ssize *
985 		DIV_ROUND_UP(srate, factor / (1 << (ep_desc->bInterval - 1)));
986 	ep_desc->wMaxPacketSize = cpu_to_le16(min_t(u16, max_packet_size,
987 				le16_to_cpu(ep_desc->wMaxPacketSize)));
988 }
989 
990 static int
991 afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
992 {
993 	struct audio_dev *agdev = func_to_agdev(fn);
994 	struct snd_uac2_chip *uac2 = &agdev->uac2;
995 	struct usb_composite_dev *cdev = cfg->cdev;
996 	struct usb_gadget *gadget = cdev->gadget;
997 	struct device *dev = &uac2->pdev.dev;
998 	struct uac2_rtd_params *prm;
999 	struct f_uac2_opts *uac2_opts;
1000 	struct usb_string *us;
1001 	int ret;
1002 
1003 	uac2_opts = container_of(fn->fi, struct f_uac2_opts, func_inst);
1004 
1005 	us = usb_gstrings_attach(cdev, fn_strings, ARRAY_SIZE(strings_fn));
1006 	if (IS_ERR(us))
1007 		return PTR_ERR(us);
1008 	iad_desc.iFunction = us[STR_ASSOC].id;
1009 	std_ac_if_desc.iInterface = us[STR_IF_CTRL].id;
1010 	in_clk_src_desc.iClockSource = us[STR_CLKSRC_IN].id;
1011 	out_clk_src_desc.iClockSource = us[STR_CLKSRC_OUT].id;
1012 	usb_out_it_desc.iTerminal = us[STR_USB_IT].id;
1013 	io_in_it_desc.iTerminal = us[STR_IO_IT].id;
1014 	usb_in_ot_desc.iTerminal = us[STR_USB_OT].id;
1015 	io_out_ot_desc.iTerminal = us[STR_IO_OT].id;
1016 	std_as_out_if0_desc.iInterface = us[STR_AS_OUT_ALT0].id;
1017 	std_as_out_if1_desc.iInterface = us[STR_AS_OUT_ALT1].id;
1018 	std_as_in_if0_desc.iInterface = us[STR_AS_IN_ALT0].id;
1019 	std_as_in_if1_desc.iInterface = us[STR_AS_IN_ALT1].id;
1020 
1021 
1022 	/* Initialize the configurable parameters */
1023 	usb_out_it_desc.bNrChannels = num_channels(uac2_opts->c_chmask);
1024 	usb_out_it_desc.bmChannelConfig = cpu_to_le32(uac2_opts->c_chmask);
1025 	io_in_it_desc.bNrChannels = num_channels(uac2_opts->p_chmask);
1026 	io_in_it_desc.bmChannelConfig = cpu_to_le32(uac2_opts->p_chmask);
1027 	as_out_hdr_desc.bNrChannels = num_channels(uac2_opts->c_chmask);
1028 	as_out_hdr_desc.bmChannelConfig = cpu_to_le32(uac2_opts->c_chmask);
1029 	as_in_hdr_desc.bNrChannels = num_channels(uac2_opts->p_chmask);
1030 	as_in_hdr_desc.bmChannelConfig = cpu_to_le32(uac2_opts->p_chmask);
1031 	as_out_fmt1_desc.bSubslotSize = uac2_opts->c_ssize;
1032 	as_out_fmt1_desc.bBitResolution = uac2_opts->c_ssize * 8;
1033 	as_in_fmt1_desc.bSubslotSize = uac2_opts->p_ssize;
1034 	as_in_fmt1_desc.bBitResolution = uac2_opts->p_ssize * 8;
1035 
1036 	snprintf(clksrc_in, sizeof(clksrc_in), "%uHz", uac2_opts->p_srate);
1037 	snprintf(clksrc_out, sizeof(clksrc_out), "%uHz", uac2_opts->c_srate);
1038 
1039 	ret = usb_interface_id(cfg, fn);
1040 	if (ret < 0) {
1041 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1042 		return ret;
1043 	}
1044 	std_ac_if_desc.bInterfaceNumber = ret;
1045 	agdev->ac_intf = ret;
1046 	agdev->ac_alt = 0;
1047 
1048 	ret = usb_interface_id(cfg, fn);
1049 	if (ret < 0) {
1050 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1051 		return ret;
1052 	}
1053 	std_as_out_if0_desc.bInterfaceNumber = ret;
1054 	std_as_out_if1_desc.bInterfaceNumber = ret;
1055 	agdev->as_out_intf = ret;
1056 	agdev->as_out_alt = 0;
1057 
1058 	ret = usb_interface_id(cfg, fn);
1059 	if (ret < 0) {
1060 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1061 		return ret;
1062 	}
1063 	std_as_in_if0_desc.bInterfaceNumber = ret;
1064 	std_as_in_if1_desc.bInterfaceNumber = ret;
1065 	agdev->as_in_intf = ret;
1066 	agdev->as_in_alt = 0;
1067 
1068 	agdev->out_ep = usb_ep_autoconfig(gadget, &fs_epout_desc);
1069 	if (!agdev->out_ep) {
1070 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1071 		return ret;
1072 	}
1073 
1074 	agdev->in_ep = usb_ep_autoconfig(gadget, &fs_epin_desc);
1075 	if (!agdev->in_ep) {
1076 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1077 		return ret;
1078 	}
1079 
1080 	uac2->p_prm.uac2 = uac2;
1081 	uac2->c_prm.uac2 = uac2;
1082 
1083 	/* Calculate wMaxPacketSize according to audio bandwidth */
1084 	set_ep_max_packet_size(uac2_opts, &fs_epin_desc, 1000, true);
1085 	set_ep_max_packet_size(uac2_opts, &fs_epout_desc, 1000, false);
1086 	set_ep_max_packet_size(uac2_opts, &hs_epin_desc, 8000, true);
1087 	set_ep_max_packet_size(uac2_opts, &hs_epout_desc, 8000, false);
1088 
1089 	hs_epout_desc.bEndpointAddress = fs_epout_desc.bEndpointAddress;
1090 	hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress;
1091 
1092 	ret = usb_assign_descriptors(fn, fs_audio_desc, hs_audio_desc, NULL,
1093 				     NULL);
1094 	if (ret)
1095 		return ret;
1096 
1097 	prm = &agdev->uac2.c_prm;
1098 	prm->max_psize = hs_epout_desc.wMaxPacketSize;
1099 	prm->ureq = kcalloc(uac2_opts->req_number, sizeof(struct uac2_req),
1100 			GFP_KERNEL);
1101 	if (!prm->ureq) {
1102 		ret = -ENOMEM;
1103 		goto err_free_descs;
1104 	}
1105 	prm->rbuf = kcalloc(uac2_opts->req_number, prm->max_psize, GFP_KERNEL);
1106 	if (!prm->rbuf) {
1107 		prm->max_psize = 0;
1108 		ret = -ENOMEM;
1109 		goto err_free_descs;
1110 	}
1111 
1112 	prm = &agdev->uac2.p_prm;
1113 	prm->max_psize = hs_epin_desc.wMaxPacketSize;
1114 	prm->ureq = kcalloc(uac2_opts->req_number, sizeof(struct uac2_req),
1115 			GFP_KERNEL);
1116 	if (!prm->ureq) {
1117 		ret = -ENOMEM;
1118 		goto err_free_descs;
1119 	}
1120 	prm->rbuf = kcalloc(uac2_opts->req_number, prm->max_psize, GFP_KERNEL);
1121 	if (!prm->rbuf) {
1122 		prm->max_psize = 0;
1123 		ret = -ENOMEM;
1124 		goto err_no_memory;
1125 	}
1126 
1127 	ret = alsa_uac2_init(agdev);
1128 	if (ret)
1129 		goto err_no_memory;
1130 	return 0;
1131 
1132 err_no_memory:
1133 	kfree(agdev->uac2.p_prm.ureq);
1134 	kfree(agdev->uac2.c_prm.ureq);
1135 	kfree(agdev->uac2.p_prm.rbuf);
1136 	kfree(agdev->uac2.c_prm.rbuf);
1137 err_free_descs:
1138 	usb_free_all_descriptors(fn);
1139 	return ret;
1140 }
1141 
1142 static int
1143 afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt)
1144 {
1145 	struct usb_composite_dev *cdev = fn->config->cdev;
1146 	struct audio_dev *agdev = func_to_agdev(fn);
1147 	struct f_uac2_opts *opts = agdev_to_uac2_opts(agdev);
1148 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1149 	struct usb_gadget *gadget = cdev->gadget;
1150 	struct device *dev = &uac2->pdev.dev;
1151 	struct usb_request *req;
1152 	struct usb_ep *ep;
1153 	struct uac2_rtd_params *prm;
1154 	int req_len, i;
1155 
1156 	/* No i/f has more than 2 alt settings */
1157 	if (alt > 1) {
1158 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1159 		return -EINVAL;
1160 	}
1161 
1162 	if (intf == agdev->ac_intf) {
1163 		/* Control I/f has only 1 AltSetting - 0 */
1164 		if (alt) {
1165 			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1166 			return -EINVAL;
1167 		}
1168 		return 0;
1169 	}
1170 
1171 	if (intf == agdev->as_out_intf) {
1172 		ep = agdev->out_ep;
1173 		prm = &uac2->c_prm;
1174 		config_ep_by_speed(gadget, fn, ep);
1175 		agdev->as_out_alt = alt;
1176 		req_len = prm->max_psize;
1177 	} else if (intf == agdev->as_in_intf) {
1178 		unsigned int factor, rate;
1179 		struct usb_endpoint_descriptor *ep_desc;
1180 
1181 		ep = agdev->in_ep;
1182 		prm = &uac2->p_prm;
1183 		config_ep_by_speed(gadget, fn, ep);
1184 		agdev->as_in_alt = alt;
1185 
1186 		/* pre-calculate the playback endpoint's interval */
1187 		if (gadget->speed == USB_SPEED_FULL) {
1188 			ep_desc = &fs_epin_desc;
1189 			factor = 1000;
1190 		} else {
1191 			ep_desc = &hs_epin_desc;
1192 			factor = 8000;
1193 		}
1194 
1195 		/* pre-compute some values for iso_complete() */
1196 		uac2->p_framesize = opts->p_ssize *
1197 				    num_channels(opts->p_chmask);
1198 		rate = opts->p_srate * uac2->p_framesize;
1199 		uac2->p_interval = factor / (1 << (ep_desc->bInterval - 1));
1200 		uac2->p_pktsize = min_t(unsigned int, rate / uac2->p_interval,
1201 					prm->max_psize);
1202 
1203 		if (uac2->p_pktsize < prm->max_psize)
1204 			uac2->p_pktsize_residue = rate % uac2->p_interval;
1205 		else
1206 			uac2->p_pktsize_residue = 0;
1207 
1208 		req_len = uac2->p_pktsize;
1209 		uac2->p_residue = 0;
1210 	} else {
1211 		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1212 		return -EINVAL;
1213 	}
1214 
1215 	if (alt == 0) {
1216 		free_ep(prm, ep);
1217 		return 0;
1218 	}
1219 
1220 	prm->ep_enabled = true;
1221 	usb_ep_enable(ep);
1222 
1223 	for (i = 0; i < opts->req_number; i++) {
1224 		if (!prm->ureq[i].req) {
1225 			req = usb_ep_alloc_request(ep, GFP_ATOMIC);
1226 			if (req == NULL)
1227 				return -ENOMEM;
1228 
1229 			prm->ureq[i].req = req;
1230 			prm->ureq[i].pp = prm;
1231 
1232 			req->zero = 0;
1233 			req->context = &prm->ureq[i];
1234 			req->length = req_len;
1235 			req->complete = agdev_iso_complete;
1236 			req->buf = prm->rbuf + i * prm->max_psize;
1237 		}
1238 
1239 		if (usb_ep_queue(ep, prm->ureq[i].req, GFP_ATOMIC))
1240 			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
1241 	}
1242 
1243 	return 0;
1244 }
1245 
1246 static int
1247 afunc_get_alt(struct usb_function *fn, unsigned intf)
1248 {
1249 	struct audio_dev *agdev = func_to_agdev(fn);
1250 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1251 
1252 	if (intf == agdev->ac_intf)
1253 		return agdev->ac_alt;
1254 	else if (intf == agdev->as_out_intf)
1255 		return agdev->as_out_alt;
1256 	else if (intf == agdev->as_in_intf)
1257 		return agdev->as_in_alt;
1258 	else
1259 		dev_err(&uac2->pdev.dev,
1260 			"%s:%d Invalid Interface %d!\n",
1261 			__func__, __LINE__, intf);
1262 
1263 	return -EINVAL;
1264 }
1265 
1266 static void
1267 afunc_disable(struct usb_function *fn)
1268 {
1269 	struct audio_dev *agdev = func_to_agdev(fn);
1270 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1271 
1272 	free_ep(&uac2->p_prm, agdev->in_ep);
1273 	agdev->as_in_alt = 0;
1274 
1275 	free_ep(&uac2->c_prm, agdev->out_ep);
1276 	agdev->as_out_alt = 0;
1277 }
1278 
1279 static int
1280 in_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1281 {
1282 	struct usb_request *req = fn->config->cdev->req;
1283 	struct audio_dev *agdev = func_to_agdev(fn);
1284 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1285 	struct f_uac2_opts *opts;
1286 	u16 w_length = le16_to_cpu(cr->wLength);
1287 	u16 w_index = le16_to_cpu(cr->wIndex);
1288 	u16 w_value = le16_to_cpu(cr->wValue);
1289 	u8 entity_id = (w_index >> 8) & 0xff;
1290 	u8 control_selector = w_value >> 8;
1291 	int value = -EOPNOTSUPP;
1292 	int p_srate, c_srate;
1293 
1294 	opts = agdev_to_uac2_opts(agdev);
1295 	p_srate = opts->p_srate;
1296 	c_srate = opts->c_srate;
1297 
1298 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
1299 		struct cntrl_cur_lay3 c;
1300 		memset(&c, 0, sizeof(struct cntrl_cur_lay3));
1301 
1302 		if (entity_id == USB_IN_CLK_ID)
1303 			c.dCUR = p_srate;
1304 		else if (entity_id == USB_OUT_CLK_ID)
1305 			c.dCUR = c_srate;
1306 
1307 		value = min_t(unsigned, w_length, sizeof c);
1308 		memcpy(req->buf, &c, value);
1309 	} else if (control_selector == UAC2_CS_CONTROL_CLOCK_VALID) {
1310 		*(u8 *)req->buf = 1;
1311 		value = min_t(unsigned, w_length, 1);
1312 	} else {
1313 		dev_err(&uac2->pdev.dev,
1314 			"%s:%d control_selector=%d TODO!\n",
1315 			__func__, __LINE__, control_selector);
1316 	}
1317 
1318 	return value;
1319 }
1320 
1321 static int
1322 in_rq_range(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1323 {
1324 	struct usb_request *req = fn->config->cdev->req;
1325 	struct audio_dev *agdev = func_to_agdev(fn);
1326 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1327 	struct f_uac2_opts *opts;
1328 	u16 w_length = le16_to_cpu(cr->wLength);
1329 	u16 w_index = le16_to_cpu(cr->wIndex);
1330 	u16 w_value = le16_to_cpu(cr->wValue);
1331 	u8 entity_id = (w_index >> 8) & 0xff;
1332 	u8 control_selector = w_value >> 8;
1333 	struct cntrl_range_lay3 r;
1334 	int value = -EOPNOTSUPP;
1335 	int p_srate, c_srate;
1336 
1337 	opts = agdev_to_uac2_opts(agdev);
1338 	p_srate = opts->p_srate;
1339 	c_srate = opts->c_srate;
1340 
1341 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
1342 		if (entity_id == USB_IN_CLK_ID)
1343 			r.dMIN = p_srate;
1344 		else if (entity_id == USB_OUT_CLK_ID)
1345 			r.dMIN = c_srate;
1346 		else
1347 			return -EOPNOTSUPP;
1348 
1349 		r.dMAX = r.dMIN;
1350 		r.dRES = 0;
1351 		r.wNumSubRanges = 1;
1352 
1353 		value = min_t(unsigned, w_length, sizeof r);
1354 		memcpy(req->buf, &r, value);
1355 	} else {
1356 		dev_err(&uac2->pdev.dev,
1357 			"%s:%d control_selector=%d TODO!\n",
1358 			__func__, __LINE__, control_selector);
1359 	}
1360 
1361 	return value;
1362 }
1363 
1364 static int
1365 ac_rq_in(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1366 {
1367 	if (cr->bRequest == UAC2_CS_CUR)
1368 		return in_rq_cur(fn, cr);
1369 	else if (cr->bRequest == UAC2_CS_RANGE)
1370 		return in_rq_range(fn, cr);
1371 	else
1372 		return -EOPNOTSUPP;
1373 }
1374 
1375 static int
1376 out_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1377 {
1378 	u16 w_length = le16_to_cpu(cr->wLength);
1379 	u16 w_value = le16_to_cpu(cr->wValue);
1380 	u8 control_selector = w_value >> 8;
1381 
1382 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ)
1383 		return w_length;
1384 
1385 	return -EOPNOTSUPP;
1386 }
1387 
1388 static int
1389 setup_rq_inf(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1390 {
1391 	struct audio_dev *agdev = func_to_agdev(fn);
1392 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1393 	u16 w_index = le16_to_cpu(cr->wIndex);
1394 	u8 intf = w_index & 0xff;
1395 
1396 	if (intf != agdev->ac_intf) {
1397 		dev_err(&uac2->pdev.dev,
1398 			"%s:%d Error!\n", __func__, __LINE__);
1399 		return -EOPNOTSUPP;
1400 	}
1401 
1402 	if (cr->bRequestType & USB_DIR_IN)
1403 		return ac_rq_in(fn, cr);
1404 	else if (cr->bRequest == UAC2_CS_CUR)
1405 		return out_rq_cur(fn, cr);
1406 
1407 	return -EOPNOTSUPP;
1408 }
1409 
1410 static int
1411 afunc_setup(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1412 {
1413 	struct usb_composite_dev *cdev = fn->config->cdev;
1414 	struct audio_dev *agdev = func_to_agdev(fn);
1415 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1416 	struct usb_request *req = cdev->req;
1417 	u16 w_length = le16_to_cpu(cr->wLength);
1418 	int value = -EOPNOTSUPP;
1419 
1420 	/* Only Class specific requests are supposed to reach here */
1421 	if ((cr->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
1422 		return -EOPNOTSUPP;
1423 
1424 	if ((cr->bRequestType & USB_RECIP_MASK) == USB_RECIP_INTERFACE)
1425 		value = setup_rq_inf(fn, cr);
1426 	else
1427 		dev_err(&uac2->pdev.dev, "%s:%d Error!\n", __func__, __LINE__);
1428 
1429 	if (value >= 0) {
1430 		req->length = value;
1431 		req->zero = value < w_length;
1432 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1433 		if (value < 0) {
1434 			dev_err(&uac2->pdev.dev,
1435 				"%s:%d Error!\n", __func__, __LINE__);
1436 			req->status = 0;
1437 		}
1438 	}
1439 
1440 	return value;
1441 }
1442 
1443 static inline struct f_uac2_opts *to_f_uac2_opts(struct config_item *item)
1444 {
1445 	return container_of(to_config_group(item), struct f_uac2_opts,
1446 			    func_inst.group);
1447 }
1448 
1449 static void f_uac2_attr_release(struct config_item *item)
1450 {
1451 	struct f_uac2_opts *opts = to_f_uac2_opts(item);
1452 
1453 	usb_put_function_instance(&opts->func_inst);
1454 }
1455 
1456 static struct configfs_item_operations f_uac2_item_ops = {
1457 	.release	= f_uac2_attr_release,
1458 };
1459 
1460 #define UAC2_ATTRIBUTE(name)						\
1461 static ssize_t f_uac2_opts_##name##_show(struct config_item *item,	\
1462 					 char *page)			\
1463 {									\
1464 	struct f_uac2_opts *opts = to_f_uac2_opts(item);		\
1465 	int result;							\
1466 									\
1467 	mutex_lock(&opts->lock);					\
1468 	result = sprintf(page, "%u\n", opts->name);			\
1469 	mutex_unlock(&opts->lock);					\
1470 									\
1471 	return result;							\
1472 }									\
1473 									\
1474 static ssize_t f_uac2_opts_##name##_store(struct config_item *item,	\
1475 					  const char *page, size_t len)	\
1476 {									\
1477 	struct f_uac2_opts *opts = to_f_uac2_opts(item);		\
1478 	int ret;							\
1479 	u32 num;							\
1480 									\
1481 	mutex_lock(&opts->lock);					\
1482 	if (opts->refcnt) {						\
1483 		ret = -EBUSY;						\
1484 		goto end;						\
1485 	}								\
1486 									\
1487 	ret = kstrtou32(page, 0, &num);					\
1488 	if (ret)							\
1489 		goto end;						\
1490 									\
1491 	opts->name = num;						\
1492 	ret = len;							\
1493 									\
1494 end:									\
1495 	mutex_unlock(&opts->lock);					\
1496 	return ret;							\
1497 }									\
1498 									\
1499 CONFIGFS_ATTR(f_uac2_opts_, name)
1500 
1501 UAC2_ATTRIBUTE(p_chmask);
1502 UAC2_ATTRIBUTE(p_srate);
1503 UAC2_ATTRIBUTE(p_ssize);
1504 UAC2_ATTRIBUTE(c_chmask);
1505 UAC2_ATTRIBUTE(c_srate);
1506 UAC2_ATTRIBUTE(c_ssize);
1507 UAC2_ATTRIBUTE(req_number);
1508 
1509 static struct configfs_attribute *f_uac2_attrs[] = {
1510 	&f_uac2_opts_attr_p_chmask,
1511 	&f_uac2_opts_attr_p_srate,
1512 	&f_uac2_opts_attr_p_ssize,
1513 	&f_uac2_opts_attr_c_chmask,
1514 	&f_uac2_opts_attr_c_srate,
1515 	&f_uac2_opts_attr_c_ssize,
1516 	&f_uac2_opts_attr_req_number,
1517 	NULL,
1518 };
1519 
1520 static struct config_item_type f_uac2_func_type = {
1521 	.ct_item_ops	= &f_uac2_item_ops,
1522 	.ct_attrs	= f_uac2_attrs,
1523 	.ct_owner	= THIS_MODULE,
1524 };
1525 
1526 static void afunc_free_inst(struct usb_function_instance *f)
1527 {
1528 	struct f_uac2_opts *opts;
1529 
1530 	opts = container_of(f, struct f_uac2_opts, func_inst);
1531 	kfree(opts);
1532 }
1533 
1534 static struct usb_function_instance *afunc_alloc_inst(void)
1535 {
1536 	struct f_uac2_opts *opts;
1537 
1538 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1539 	if (!opts)
1540 		return ERR_PTR(-ENOMEM);
1541 
1542 	mutex_init(&opts->lock);
1543 	opts->func_inst.free_func_inst = afunc_free_inst;
1544 
1545 	config_group_init_type_name(&opts->func_inst.group, "",
1546 				    &f_uac2_func_type);
1547 
1548 	opts->p_chmask = UAC2_DEF_PCHMASK;
1549 	opts->p_srate = UAC2_DEF_PSRATE;
1550 	opts->p_ssize = UAC2_DEF_PSSIZE;
1551 	opts->c_chmask = UAC2_DEF_CCHMASK;
1552 	opts->c_srate = UAC2_DEF_CSRATE;
1553 	opts->c_ssize = UAC2_DEF_CSSIZE;
1554 	opts->req_number = UAC2_DEF_REQ_NUM;
1555 	return &opts->func_inst;
1556 }
1557 
1558 static void afunc_free(struct usb_function *f)
1559 {
1560 	struct audio_dev *agdev;
1561 	struct f_uac2_opts *opts;
1562 
1563 	agdev = func_to_agdev(f);
1564 	opts = container_of(f->fi, struct f_uac2_opts, func_inst);
1565 	kfree(agdev);
1566 	mutex_lock(&opts->lock);
1567 	--opts->refcnt;
1568 	mutex_unlock(&opts->lock);
1569 }
1570 
1571 static void afunc_unbind(struct usb_configuration *c, struct usb_function *f)
1572 {
1573 	struct audio_dev *agdev = func_to_agdev(f);
1574 	struct uac2_rtd_params *prm;
1575 
1576 	alsa_uac2_exit(agdev);
1577 
1578 	prm = &agdev->uac2.p_prm;
1579 	kfree(prm->rbuf);
1580 
1581 	prm = &agdev->uac2.c_prm;
1582 	kfree(prm->rbuf);
1583 	kfree(prm->ureq);
1584 	usb_free_all_descriptors(f);
1585 }
1586 
1587 static struct usb_function *afunc_alloc(struct usb_function_instance *fi)
1588 {
1589 	struct audio_dev *agdev;
1590 	struct f_uac2_opts *opts;
1591 
1592 	agdev = kzalloc(sizeof(*agdev), GFP_KERNEL);
1593 	if (agdev == NULL)
1594 		return ERR_PTR(-ENOMEM);
1595 
1596 	opts = container_of(fi, struct f_uac2_opts, func_inst);
1597 	mutex_lock(&opts->lock);
1598 	++opts->refcnt;
1599 	mutex_unlock(&opts->lock);
1600 
1601 	agdev->func.name = "uac2_func";
1602 	agdev->func.bind = afunc_bind;
1603 	agdev->func.unbind = afunc_unbind;
1604 	agdev->func.set_alt = afunc_set_alt;
1605 	agdev->func.get_alt = afunc_get_alt;
1606 	agdev->func.disable = afunc_disable;
1607 	agdev->func.setup = afunc_setup;
1608 	agdev->func.free_func = afunc_free;
1609 
1610 	return &agdev->func;
1611 }
1612 
1613 DECLARE_USB_FUNCTION_INIT(uac2, afunc_alloc_inst, afunc_alloc);
1614 MODULE_LICENSE("GPL");
1615 MODULE_AUTHOR("Yadwinder Singh");
1616 MODULE_AUTHOR("Jaswinder Singh");
1617