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 /* Playback(USB-IN) Default Stereo - Fl/Fr */
24 static int p_chmask = 0x3;
25 module_param(p_chmask, uint, S_IRUGO);
26 MODULE_PARM_DESC(p_chmask, "Playback Channel Mask");
27 
28 /* Playback Default 48 KHz */
29 static int p_srate = 48000;
30 module_param(p_srate, uint, S_IRUGO);
31 MODULE_PARM_DESC(p_srate, "Playback Sampling Rate");
32 
33 /* Playback Default 16bits/sample */
34 static int p_ssize = 2;
35 module_param(p_ssize, uint, S_IRUGO);
36 MODULE_PARM_DESC(p_ssize, "Playback Sample Size(bytes)");
37 
38 /* Capture(USB-OUT) Default Stereo - Fl/Fr */
39 static int c_chmask = 0x3;
40 module_param(c_chmask, uint, S_IRUGO);
41 MODULE_PARM_DESC(c_chmask, "Capture Channel Mask");
42 
43 /* Capture Default 64 KHz */
44 static int c_srate = 64000;
45 module_param(c_srate, uint, S_IRUGO);
46 MODULE_PARM_DESC(c_srate, "Capture Sampling Rate");
47 
48 /* Capture Default 16bits/sample */
49 static int c_ssize = 2;
50 module_param(c_ssize, uint, S_IRUGO);
51 MODULE_PARM_DESC(c_ssize, "Capture Sample Size(bytes)");
52 
53 /* Keep everyone on toes */
54 #define USB_XFERS	2
55 
56 /*
57  * The driver implements a simple UAC_2 topology.
58  * USB-OUT -> IT_1 -> OT_3 -> ALSA_Capture
59  * ALSA_Playback -> IT_2 -> OT_4 -> USB-IN
60  * Capture and Playback sampling rates are independently
61  *  controlled by two clock sources :
62  *    CLK_5 := c_srate, and CLK_6 := p_srate
63  */
64 #define USB_OUT_IT_ID	1
65 #define IO_IN_IT_ID	2
66 #define IO_OUT_OT_ID	3
67 #define USB_IN_OT_ID	4
68 #define USB_OUT_CLK_ID	5
69 #define USB_IN_CLK_ID	6
70 
71 #define CONTROL_ABSENT	0
72 #define CONTROL_RDONLY	1
73 #define CONTROL_RDWR	3
74 
75 #define CLK_FREQ_CTRL	0
76 #define CLK_VLD_CTRL	2
77 
78 #define COPY_CTRL	0
79 #define CONN_CTRL	2
80 #define OVRLD_CTRL	4
81 #define CLSTR_CTRL	6
82 #define UNFLW_CTRL	8
83 #define OVFLW_CTRL	10
84 
85 const char *uac2_name = "snd_uac2";
86 
87 struct uac2_req {
88 	struct uac2_rtd_params *pp; /* parent param */
89 	struct usb_request *req;
90 };
91 
92 struct uac2_rtd_params {
93 	struct snd_uac2_chip *uac2; /* parent chip */
94 	bool ep_enabled; /* if the ep is enabled */
95 	/* Size of the ring buffer */
96 	size_t dma_bytes;
97 	unsigned char *dma_area;
98 
99 	struct snd_pcm_substream *ss;
100 
101 	/* Ring buffer */
102 	ssize_t hw_ptr;
103 
104 	void *rbuf;
105 
106 	size_t period_size;
107 
108 	unsigned max_psize;
109 	struct uac2_req ureq[USB_XFERS];
110 
111 	spinlock_t lock;
112 };
113 
114 struct snd_uac2_chip {
115 	struct platform_device pdev;
116 	struct platform_driver pdrv;
117 
118 	struct uac2_rtd_params p_prm;
119 	struct uac2_rtd_params c_prm;
120 
121 	struct snd_card *card;
122 	struct snd_pcm *pcm;
123 };
124 
125 #define BUFF_SIZE_MAX	(PAGE_SIZE * 16)
126 #define PRD_SIZE_MAX	PAGE_SIZE
127 #define MIN_PERIODS	4
128 
129 static struct snd_pcm_hardware uac2_pcm_hardware = {
130 	.info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER
131 		 | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID
132 		 | SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME,
133 	.rates = SNDRV_PCM_RATE_CONTINUOUS,
134 	.periods_max = BUFF_SIZE_MAX / PRD_SIZE_MAX,
135 	.buffer_bytes_max = BUFF_SIZE_MAX,
136 	.period_bytes_max = PRD_SIZE_MAX,
137 	.periods_min = MIN_PERIODS,
138 };
139 
140 struct audio_dev {
141 	u8 ac_intf, ac_alt;
142 	u8 as_out_intf, as_out_alt;
143 	u8 as_in_intf, as_in_alt;
144 
145 	struct usb_ep *in_ep, *out_ep;
146 	struct usb_function func;
147 
148 	/* The ALSA Sound Card it represents on the USB-Client side */
149 	struct snd_uac2_chip uac2;
150 };
151 
152 static struct audio_dev *agdev_g;
153 
154 static inline
155 struct audio_dev *func_to_agdev(struct usb_function *f)
156 {
157 	return container_of(f, struct audio_dev, func);
158 }
159 
160 static inline
161 struct audio_dev *uac2_to_agdev(struct snd_uac2_chip *u)
162 {
163 	return container_of(u, struct audio_dev, uac2);
164 }
165 
166 static inline
167 struct snd_uac2_chip *pdev_to_uac2(struct platform_device *p)
168 {
169 	return container_of(p, struct snd_uac2_chip, pdev);
170 }
171 
172 static inline
173 uint num_channels(uint chanmask)
174 {
175 	uint num = 0;
176 
177 	while (chanmask) {
178 		num += (chanmask & 1);
179 		chanmask >>= 1;
180 	}
181 
182 	return num;
183 }
184 
185 static void
186 agdev_iso_complete(struct usb_ep *ep, struct usb_request *req)
187 {
188 	unsigned pending;
189 	unsigned long flags;
190 	bool update_alsa = false;
191 	unsigned char *src, *dst;
192 	int status = req->status;
193 	struct uac2_req *ur = req->context;
194 	struct snd_pcm_substream *substream;
195 	struct uac2_rtd_params *prm = ur->pp;
196 	struct snd_uac2_chip *uac2 = prm->uac2;
197 
198 	/* i/f shutting down */
199 	if (!prm->ep_enabled || req->status == -ESHUTDOWN)
200 		return;
201 
202 	/*
203 	 * We can't really do much about bad xfers.
204 	 * Afterall, the ISOCH xfers could fail legitimately.
205 	 */
206 	if (status)
207 		pr_debug("%s: iso_complete status(%d) %d/%d\n",
208 			__func__, status, req->actual, req->length);
209 
210 	substream = prm->ss;
211 
212 	/* Do nothing if ALSA isn't active */
213 	if (!substream)
214 		goto exit;
215 
216 	spin_lock_irqsave(&prm->lock, flags);
217 
218 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
219 		src = prm->dma_area + prm->hw_ptr;
220 		req->actual = req->length;
221 		dst = req->buf;
222 	} else {
223 		dst = prm->dma_area + prm->hw_ptr;
224 		src = req->buf;
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 	prm->hw_ptr = (prm->hw_ptr + req->actual) % prm->dma_bytes;
233 
234 	spin_unlock_irqrestore(&prm->lock, flags);
235 
236 	/* Pack USB load in ALSA ring buffer */
237 	memcpy(dst, src, req->actual);
238 exit:
239 	if (usb_ep_queue(ep, req, GFP_ATOMIC))
240 		dev_err(&uac2->pdev.dev, "%d Error!\n", __LINE__);
241 
242 	if (update_alsa)
243 		snd_pcm_period_elapsed(substream);
244 
245 	return;
246 }
247 
248 static int
249 uac2_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
250 {
251 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
252 	struct uac2_rtd_params *prm;
253 	unsigned long flags;
254 	int err = 0;
255 
256 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
257 		prm = &uac2->p_prm;
258 	else
259 		prm = &uac2->c_prm;
260 
261 	spin_lock_irqsave(&prm->lock, flags);
262 
263 	/* Reset */
264 	prm->hw_ptr = 0;
265 
266 	switch (cmd) {
267 	case SNDRV_PCM_TRIGGER_START:
268 	case SNDRV_PCM_TRIGGER_RESUME:
269 		prm->ss = substream;
270 		break;
271 	case SNDRV_PCM_TRIGGER_STOP:
272 	case SNDRV_PCM_TRIGGER_SUSPEND:
273 		prm->ss = NULL;
274 		break;
275 	default:
276 		err = -EINVAL;
277 	}
278 
279 	spin_unlock_irqrestore(&prm->lock, flags);
280 
281 	/* Clear buffer after Play stops */
282 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && !prm->ss)
283 		memset(prm->rbuf, 0, prm->max_psize * USB_XFERS);
284 
285 	return err;
286 }
287 
288 static snd_pcm_uframes_t uac2_pcm_pointer(struct snd_pcm_substream *substream)
289 {
290 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
291 	struct uac2_rtd_params *prm;
292 
293 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
294 		prm = &uac2->p_prm;
295 	else
296 		prm = &uac2->c_prm;
297 
298 	return bytes_to_frames(substream->runtime, prm->hw_ptr);
299 }
300 
301 static int uac2_pcm_hw_params(struct snd_pcm_substream *substream,
302 			       struct snd_pcm_hw_params *hw_params)
303 {
304 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
305 	struct uac2_rtd_params *prm;
306 	int err;
307 
308 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
309 		prm = &uac2->p_prm;
310 	else
311 		prm = &uac2->c_prm;
312 
313 	err = snd_pcm_lib_malloc_pages(substream,
314 					params_buffer_bytes(hw_params));
315 	if (err >= 0) {
316 		prm->dma_bytes = substream->runtime->dma_bytes;
317 		prm->dma_area = substream->runtime->dma_area;
318 		prm->period_size = params_period_bytes(hw_params);
319 	}
320 
321 	return err;
322 }
323 
324 static int uac2_pcm_hw_free(struct snd_pcm_substream *substream)
325 {
326 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
327 	struct uac2_rtd_params *prm;
328 
329 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
330 		prm = &uac2->p_prm;
331 	else
332 		prm = &uac2->c_prm;
333 
334 	prm->dma_area = NULL;
335 	prm->dma_bytes = 0;
336 	prm->period_size = 0;
337 
338 	return snd_pcm_lib_free_pages(substream);
339 }
340 
341 static int uac2_pcm_open(struct snd_pcm_substream *substream)
342 {
343 	struct snd_uac2_chip *uac2 = snd_pcm_substream_chip(substream);
344 	struct snd_pcm_runtime *runtime = substream->runtime;
345 
346 	runtime->hw = uac2_pcm_hardware;
347 
348 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
349 		spin_lock_init(&uac2->p_prm.lock);
350 		runtime->hw.rate_min = p_srate;
351 		switch (p_ssize) {
352 		case 3:
353 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S24_3LE;
354 			break;
355 		case 4:
356 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S32_LE;
357 			break;
358 		default:
359 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S16_LE;
360 			break;
361 		}
362 		runtime->hw.channels_min = num_channels(p_chmask);
363 		runtime->hw.period_bytes_min = 2 * uac2->p_prm.max_psize
364 						/ runtime->hw.periods_min;
365 	} else {
366 		spin_lock_init(&uac2->c_prm.lock);
367 		runtime->hw.rate_min = c_srate;
368 		switch (c_ssize) {
369 		case 3:
370 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S24_3LE;
371 			break;
372 		case 4:
373 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S32_LE;
374 			break;
375 		default:
376 			runtime->hw.formats = SNDRV_PCM_FMTBIT_S16_LE;
377 			break;
378 		}
379 		runtime->hw.channels_min = num_channels(c_chmask);
380 		runtime->hw.period_bytes_min = 2 * uac2->c_prm.max_psize
381 						/ runtime->hw.periods_min;
382 	}
383 
384 	runtime->hw.rate_max = runtime->hw.rate_min;
385 	runtime->hw.channels_max = runtime->hw.channels_min;
386 
387 	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
388 
389 	return 0;
390 }
391 
392 /* ALSA cries without these function pointers */
393 static int uac2_pcm_null(struct snd_pcm_substream *substream)
394 {
395 	return 0;
396 }
397 
398 static struct snd_pcm_ops uac2_pcm_ops = {
399 	.open = uac2_pcm_open,
400 	.close = uac2_pcm_null,
401 	.ioctl = snd_pcm_lib_ioctl,
402 	.hw_params = uac2_pcm_hw_params,
403 	.hw_free = uac2_pcm_hw_free,
404 	.trigger = uac2_pcm_trigger,
405 	.pointer = uac2_pcm_pointer,
406 	.prepare = uac2_pcm_null,
407 };
408 
409 static int snd_uac2_probe(struct platform_device *pdev)
410 {
411 	struct snd_uac2_chip *uac2 = pdev_to_uac2(pdev);
412 	struct snd_card *card;
413 	struct snd_pcm *pcm;
414 	int err;
415 
416 	/* Choose any slot, with no id */
417 	err = snd_card_new(&pdev->dev, -1, NULL, THIS_MODULE, 0, &card);
418 	if (err < 0)
419 		return err;
420 
421 	uac2->card = card;
422 
423 	/*
424 	 * Create first PCM device
425 	 * Create a substream only for non-zero channel streams
426 	 */
427 	err = snd_pcm_new(uac2->card, "UAC2 PCM", 0,
428 			       p_chmask ? 1 : 0, c_chmask ? 1 : 0, &pcm);
429 	if (err < 0)
430 		goto snd_fail;
431 
432 	strcpy(pcm->name, "UAC2 PCM");
433 	pcm->private_data = uac2;
434 
435 	uac2->pcm = pcm;
436 
437 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &uac2_pcm_ops);
438 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &uac2_pcm_ops);
439 
440 	strcpy(card->driver, "UAC2_Gadget");
441 	strcpy(card->shortname, "UAC2_Gadget");
442 	sprintf(card->longname, "UAC2_Gadget %i", pdev->id);
443 
444 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
445 		snd_dma_continuous_data(GFP_KERNEL), 0, BUFF_SIZE_MAX);
446 
447 	err = snd_card_register(card);
448 	if (!err) {
449 		platform_set_drvdata(pdev, card);
450 		return 0;
451 	}
452 
453 snd_fail:
454 	snd_card_free(card);
455 
456 	uac2->pcm = NULL;
457 	uac2->card = NULL;
458 
459 	return err;
460 }
461 
462 static int snd_uac2_remove(struct platform_device *pdev)
463 {
464 	struct snd_card *card = platform_get_drvdata(pdev);
465 
466 	if (card)
467 		return snd_card_free(card);
468 
469 	return 0;
470 }
471 
472 static int alsa_uac2_init(struct audio_dev *agdev)
473 {
474 	struct snd_uac2_chip *uac2 = &agdev->uac2;
475 	int err;
476 
477 	uac2->pdrv.probe = snd_uac2_probe;
478 	uac2->pdrv.remove = snd_uac2_remove;
479 	uac2->pdrv.driver.name = uac2_name;
480 
481 	uac2->pdev.id = 0;
482 	uac2->pdev.name = uac2_name;
483 
484 	/* Register snd_uac2 driver */
485 	err = platform_driver_register(&uac2->pdrv);
486 	if (err)
487 		return err;
488 
489 	/* Register snd_uac2 device */
490 	err = platform_device_register(&uac2->pdev);
491 	if (err)
492 		platform_driver_unregister(&uac2->pdrv);
493 
494 	return err;
495 }
496 
497 static void alsa_uac2_exit(struct audio_dev *agdev)
498 {
499 	struct snd_uac2_chip *uac2 = &agdev->uac2;
500 
501 	platform_driver_unregister(&uac2->pdrv);
502 	platform_device_unregister(&uac2->pdev);
503 }
504 
505 
506 /* --------- USB Function Interface ------------- */
507 
508 enum {
509 	STR_ASSOC,
510 	STR_IF_CTRL,
511 	STR_CLKSRC_IN,
512 	STR_CLKSRC_OUT,
513 	STR_USB_IT,
514 	STR_IO_IT,
515 	STR_USB_OT,
516 	STR_IO_OT,
517 	STR_AS_OUT_ALT0,
518 	STR_AS_OUT_ALT1,
519 	STR_AS_IN_ALT0,
520 	STR_AS_IN_ALT1,
521 };
522 
523 static char clksrc_in[8];
524 static char clksrc_out[8];
525 
526 static struct usb_string strings_fn[] = {
527 	[STR_ASSOC].s = "Source/Sink",
528 	[STR_IF_CTRL].s = "Topology Control",
529 	[STR_CLKSRC_IN].s = clksrc_in,
530 	[STR_CLKSRC_OUT].s = clksrc_out,
531 	[STR_USB_IT].s = "USBH Out",
532 	[STR_IO_IT].s = "USBD Out",
533 	[STR_USB_OT].s = "USBH In",
534 	[STR_IO_OT].s = "USBD In",
535 	[STR_AS_OUT_ALT0].s = "Playback Inactive",
536 	[STR_AS_OUT_ALT1].s = "Playback Active",
537 	[STR_AS_IN_ALT0].s = "Capture Inactive",
538 	[STR_AS_IN_ALT1].s = "Capture Active",
539 	{ },
540 };
541 
542 static struct usb_gadget_strings str_fn = {
543 	.language = 0x0409,	/* en-us */
544 	.strings = strings_fn,
545 };
546 
547 static struct usb_gadget_strings *fn_strings[] = {
548 	&str_fn,
549 	NULL,
550 };
551 
552 static struct usb_qualifier_descriptor devqual_desc = {
553 	.bLength = sizeof devqual_desc,
554 	.bDescriptorType = USB_DT_DEVICE_QUALIFIER,
555 
556 	.bcdUSB = cpu_to_le16(0x200),
557 	.bDeviceClass = USB_CLASS_MISC,
558 	.bDeviceSubClass = 0x02,
559 	.bDeviceProtocol = 0x01,
560 	.bNumConfigurations = 1,
561 	.bRESERVED = 0,
562 };
563 
564 static struct usb_interface_assoc_descriptor iad_desc = {
565 	.bLength = sizeof iad_desc,
566 	.bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
567 
568 	.bFirstInterface = 0,
569 	.bInterfaceCount = 3,
570 	.bFunctionClass = USB_CLASS_AUDIO,
571 	.bFunctionSubClass = UAC2_FUNCTION_SUBCLASS_UNDEFINED,
572 	.bFunctionProtocol = UAC_VERSION_2,
573 };
574 
575 /* Audio Control Interface */
576 static struct usb_interface_descriptor std_ac_if_desc = {
577 	.bLength = sizeof std_ac_if_desc,
578 	.bDescriptorType = USB_DT_INTERFACE,
579 
580 	.bAlternateSetting = 0,
581 	.bNumEndpoints = 0,
582 	.bInterfaceClass = USB_CLASS_AUDIO,
583 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL,
584 	.bInterfaceProtocol = UAC_VERSION_2,
585 };
586 
587 /* Clock source for IN traffic */
588 struct uac_clock_source_descriptor in_clk_src_desc = {
589 	.bLength = sizeof in_clk_src_desc,
590 	.bDescriptorType = USB_DT_CS_INTERFACE,
591 
592 	.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
593 	.bClockID = USB_IN_CLK_ID,
594 	.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
595 	.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
596 	.bAssocTerminal = 0,
597 };
598 
599 /* Clock source for OUT traffic */
600 struct uac_clock_source_descriptor out_clk_src_desc = {
601 	.bLength = sizeof out_clk_src_desc,
602 	.bDescriptorType = USB_DT_CS_INTERFACE,
603 
604 	.bDescriptorSubtype = UAC2_CLOCK_SOURCE,
605 	.bClockID = USB_OUT_CLK_ID,
606 	.bmAttributes = UAC_CLOCK_SOURCE_TYPE_INT_FIXED,
607 	.bmControls = (CONTROL_RDONLY << CLK_FREQ_CTRL),
608 	.bAssocTerminal = 0,
609 };
610 
611 /* Input Terminal for USB_OUT */
612 struct uac2_input_terminal_descriptor usb_out_it_desc = {
613 	.bLength = sizeof usb_out_it_desc,
614 	.bDescriptorType = USB_DT_CS_INTERFACE,
615 
616 	.bDescriptorSubtype = UAC_INPUT_TERMINAL,
617 	.bTerminalID = USB_OUT_IT_ID,
618 	.wTerminalType = cpu_to_le16(UAC_TERMINAL_STREAMING),
619 	.bAssocTerminal = 0,
620 	.bCSourceID = USB_OUT_CLK_ID,
621 	.iChannelNames = 0,
622 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
623 };
624 
625 /* Input Terminal for I/O-In */
626 struct uac2_input_terminal_descriptor io_in_it_desc = {
627 	.bLength = sizeof io_in_it_desc,
628 	.bDescriptorType = USB_DT_CS_INTERFACE,
629 
630 	.bDescriptorSubtype = UAC_INPUT_TERMINAL,
631 	.bTerminalID = IO_IN_IT_ID,
632 	.wTerminalType = cpu_to_le16(UAC_INPUT_TERMINAL_UNDEFINED),
633 	.bAssocTerminal = 0,
634 	.bCSourceID = USB_IN_CLK_ID,
635 	.iChannelNames = 0,
636 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
637 };
638 
639 /* Ouput Terminal for USB_IN */
640 struct uac2_output_terminal_descriptor usb_in_ot_desc = {
641 	.bLength = sizeof usb_in_ot_desc,
642 	.bDescriptorType = USB_DT_CS_INTERFACE,
643 
644 	.bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
645 	.bTerminalID = USB_IN_OT_ID,
646 	.wTerminalType = cpu_to_le16(UAC_TERMINAL_STREAMING),
647 	.bAssocTerminal = 0,
648 	.bSourceID = IO_IN_IT_ID,
649 	.bCSourceID = USB_IN_CLK_ID,
650 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
651 };
652 
653 /* Ouput Terminal for I/O-Out */
654 struct uac2_output_terminal_descriptor io_out_ot_desc = {
655 	.bLength = sizeof io_out_ot_desc,
656 	.bDescriptorType = USB_DT_CS_INTERFACE,
657 
658 	.bDescriptorSubtype = UAC_OUTPUT_TERMINAL,
659 	.bTerminalID = IO_OUT_OT_ID,
660 	.wTerminalType = cpu_to_le16(UAC_OUTPUT_TERMINAL_UNDEFINED),
661 	.bAssocTerminal = 0,
662 	.bSourceID = USB_OUT_IT_ID,
663 	.bCSourceID = USB_OUT_CLK_ID,
664 	.bmControls = (CONTROL_RDWR << COPY_CTRL),
665 };
666 
667 struct uac2_ac_header_descriptor ac_hdr_desc = {
668 	.bLength = sizeof ac_hdr_desc,
669 	.bDescriptorType = USB_DT_CS_INTERFACE,
670 
671 	.bDescriptorSubtype = UAC_MS_HEADER,
672 	.bcdADC = cpu_to_le16(0x200),
673 	.bCategory = UAC2_FUNCTION_IO_BOX,
674 	.wTotalLength = sizeof in_clk_src_desc + sizeof out_clk_src_desc
675 			 + sizeof usb_out_it_desc + sizeof io_in_it_desc
676 			+ sizeof usb_in_ot_desc + sizeof io_out_ot_desc,
677 	.bmControls = 0,
678 };
679 
680 /* Audio Streaming OUT Interface - Alt0 */
681 static struct usb_interface_descriptor std_as_out_if0_desc = {
682 	.bLength = sizeof std_as_out_if0_desc,
683 	.bDescriptorType = USB_DT_INTERFACE,
684 
685 	.bAlternateSetting = 0,
686 	.bNumEndpoints = 0,
687 	.bInterfaceClass = USB_CLASS_AUDIO,
688 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
689 	.bInterfaceProtocol = UAC_VERSION_2,
690 };
691 
692 /* Audio Streaming OUT Interface - Alt1 */
693 static struct usb_interface_descriptor std_as_out_if1_desc = {
694 	.bLength = sizeof std_as_out_if1_desc,
695 	.bDescriptorType = USB_DT_INTERFACE,
696 
697 	.bAlternateSetting = 1,
698 	.bNumEndpoints = 1,
699 	.bInterfaceClass = USB_CLASS_AUDIO,
700 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
701 	.bInterfaceProtocol = UAC_VERSION_2,
702 };
703 
704 /* Audio Stream OUT Intface Desc */
705 struct uac2_as_header_descriptor as_out_hdr_desc = {
706 	.bLength = sizeof as_out_hdr_desc,
707 	.bDescriptorType = USB_DT_CS_INTERFACE,
708 
709 	.bDescriptorSubtype = UAC_AS_GENERAL,
710 	.bTerminalLink = USB_OUT_IT_ID,
711 	.bmControls = 0,
712 	.bFormatType = UAC_FORMAT_TYPE_I,
713 	.bmFormats = cpu_to_le32(UAC_FORMAT_TYPE_I_PCM),
714 	.iChannelNames = 0,
715 };
716 
717 /* Audio USB_OUT Format */
718 struct uac2_format_type_i_descriptor as_out_fmt1_desc = {
719 	.bLength = sizeof as_out_fmt1_desc,
720 	.bDescriptorType = USB_DT_CS_INTERFACE,
721 	.bDescriptorSubtype = UAC_FORMAT_TYPE,
722 	.bFormatType = UAC_FORMAT_TYPE_I,
723 };
724 
725 /* STD AS ISO OUT Endpoint */
726 struct usb_endpoint_descriptor fs_epout_desc = {
727 	.bLength = USB_DT_ENDPOINT_SIZE,
728 	.bDescriptorType = USB_DT_ENDPOINT,
729 
730 	.bEndpointAddress = USB_DIR_OUT,
731 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
732 	.bInterval = 1,
733 };
734 
735 struct usb_endpoint_descriptor hs_epout_desc = {
736 	.bLength = USB_DT_ENDPOINT_SIZE,
737 	.bDescriptorType = USB_DT_ENDPOINT,
738 
739 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
740 	.bInterval = 4,
741 };
742 
743 /* CS AS ISO OUT Endpoint */
744 static struct uac2_iso_endpoint_descriptor as_iso_out_desc = {
745 	.bLength = sizeof as_iso_out_desc,
746 	.bDescriptorType = USB_DT_CS_ENDPOINT,
747 
748 	.bDescriptorSubtype = UAC_EP_GENERAL,
749 	.bmAttributes = 0,
750 	.bmControls = 0,
751 	.bLockDelayUnits = 0,
752 	.wLockDelay = 0,
753 };
754 
755 /* Audio Streaming IN Interface - Alt0 */
756 static struct usb_interface_descriptor std_as_in_if0_desc = {
757 	.bLength = sizeof std_as_in_if0_desc,
758 	.bDescriptorType = USB_DT_INTERFACE,
759 
760 	.bAlternateSetting = 0,
761 	.bNumEndpoints = 0,
762 	.bInterfaceClass = USB_CLASS_AUDIO,
763 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
764 	.bInterfaceProtocol = UAC_VERSION_2,
765 };
766 
767 /* Audio Streaming IN Interface - Alt1 */
768 static struct usb_interface_descriptor std_as_in_if1_desc = {
769 	.bLength = sizeof std_as_in_if1_desc,
770 	.bDescriptorType = USB_DT_INTERFACE,
771 
772 	.bAlternateSetting = 1,
773 	.bNumEndpoints = 1,
774 	.bInterfaceClass = USB_CLASS_AUDIO,
775 	.bInterfaceSubClass = USB_SUBCLASS_AUDIOSTREAMING,
776 	.bInterfaceProtocol = UAC_VERSION_2,
777 };
778 
779 /* Audio Stream IN Intface Desc */
780 struct uac2_as_header_descriptor as_in_hdr_desc = {
781 	.bLength = sizeof as_in_hdr_desc,
782 	.bDescriptorType = USB_DT_CS_INTERFACE,
783 
784 	.bDescriptorSubtype = UAC_AS_GENERAL,
785 	.bTerminalLink = USB_IN_OT_ID,
786 	.bmControls = 0,
787 	.bFormatType = UAC_FORMAT_TYPE_I,
788 	.bmFormats = cpu_to_le32(UAC_FORMAT_TYPE_I_PCM),
789 	.iChannelNames = 0,
790 };
791 
792 /* Audio USB_IN Format */
793 struct uac2_format_type_i_descriptor as_in_fmt1_desc = {
794 	.bLength = sizeof as_in_fmt1_desc,
795 	.bDescriptorType = USB_DT_CS_INTERFACE,
796 	.bDescriptorSubtype = UAC_FORMAT_TYPE,
797 	.bFormatType = UAC_FORMAT_TYPE_I,
798 };
799 
800 /* STD AS ISO IN Endpoint */
801 struct usb_endpoint_descriptor fs_epin_desc = {
802 	.bLength = USB_DT_ENDPOINT_SIZE,
803 	.bDescriptorType = USB_DT_ENDPOINT,
804 
805 	.bEndpointAddress = USB_DIR_IN,
806 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
807 	.bInterval = 1,
808 };
809 
810 struct usb_endpoint_descriptor hs_epin_desc = {
811 	.bLength = USB_DT_ENDPOINT_SIZE,
812 	.bDescriptorType = USB_DT_ENDPOINT,
813 
814 	.bmAttributes = USB_ENDPOINT_XFER_ISOC | USB_ENDPOINT_SYNC_ASYNC,
815 	.bInterval = 4,
816 };
817 
818 /* CS AS ISO IN Endpoint */
819 static struct uac2_iso_endpoint_descriptor as_iso_in_desc = {
820 	.bLength = sizeof as_iso_in_desc,
821 	.bDescriptorType = USB_DT_CS_ENDPOINT,
822 
823 	.bDescriptorSubtype = UAC_EP_GENERAL,
824 	.bmAttributes = 0,
825 	.bmControls = 0,
826 	.bLockDelayUnits = 0,
827 	.wLockDelay = 0,
828 };
829 
830 static struct usb_descriptor_header *fs_audio_desc[] = {
831 	(struct usb_descriptor_header *)&iad_desc,
832 	(struct usb_descriptor_header *)&std_ac_if_desc,
833 
834 	(struct usb_descriptor_header *)&ac_hdr_desc,
835 	(struct usb_descriptor_header *)&in_clk_src_desc,
836 	(struct usb_descriptor_header *)&out_clk_src_desc,
837 	(struct usb_descriptor_header *)&usb_out_it_desc,
838 	(struct usb_descriptor_header *)&io_in_it_desc,
839 	(struct usb_descriptor_header *)&usb_in_ot_desc,
840 	(struct usb_descriptor_header *)&io_out_ot_desc,
841 
842 	(struct usb_descriptor_header *)&std_as_out_if0_desc,
843 	(struct usb_descriptor_header *)&std_as_out_if1_desc,
844 
845 	(struct usb_descriptor_header *)&as_out_hdr_desc,
846 	(struct usb_descriptor_header *)&as_out_fmt1_desc,
847 	(struct usb_descriptor_header *)&fs_epout_desc,
848 	(struct usb_descriptor_header *)&as_iso_out_desc,
849 
850 	(struct usb_descriptor_header *)&std_as_in_if0_desc,
851 	(struct usb_descriptor_header *)&std_as_in_if1_desc,
852 
853 	(struct usb_descriptor_header *)&as_in_hdr_desc,
854 	(struct usb_descriptor_header *)&as_in_fmt1_desc,
855 	(struct usb_descriptor_header *)&fs_epin_desc,
856 	(struct usb_descriptor_header *)&as_iso_in_desc,
857 	NULL,
858 };
859 
860 static struct usb_descriptor_header *hs_audio_desc[] = {
861 	(struct usb_descriptor_header *)&iad_desc,
862 	(struct usb_descriptor_header *)&std_ac_if_desc,
863 
864 	(struct usb_descriptor_header *)&ac_hdr_desc,
865 	(struct usb_descriptor_header *)&in_clk_src_desc,
866 	(struct usb_descriptor_header *)&out_clk_src_desc,
867 	(struct usb_descriptor_header *)&usb_out_it_desc,
868 	(struct usb_descriptor_header *)&io_in_it_desc,
869 	(struct usb_descriptor_header *)&usb_in_ot_desc,
870 	(struct usb_descriptor_header *)&io_out_ot_desc,
871 
872 	(struct usb_descriptor_header *)&std_as_out_if0_desc,
873 	(struct usb_descriptor_header *)&std_as_out_if1_desc,
874 
875 	(struct usb_descriptor_header *)&as_out_hdr_desc,
876 	(struct usb_descriptor_header *)&as_out_fmt1_desc,
877 	(struct usb_descriptor_header *)&hs_epout_desc,
878 	(struct usb_descriptor_header *)&as_iso_out_desc,
879 
880 	(struct usb_descriptor_header *)&std_as_in_if0_desc,
881 	(struct usb_descriptor_header *)&std_as_in_if1_desc,
882 
883 	(struct usb_descriptor_header *)&as_in_hdr_desc,
884 	(struct usb_descriptor_header *)&as_in_fmt1_desc,
885 	(struct usb_descriptor_header *)&hs_epin_desc,
886 	(struct usb_descriptor_header *)&as_iso_in_desc,
887 	NULL,
888 };
889 
890 struct cntrl_cur_lay3 {
891 	__u32	dCUR;
892 };
893 
894 struct cntrl_range_lay3 {
895 	__u16	wNumSubRanges;
896 	__u32	dMIN;
897 	__u32	dMAX;
898 	__u32	dRES;
899 } __packed;
900 
901 static inline void
902 free_ep(struct uac2_rtd_params *prm, struct usb_ep *ep)
903 {
904 	struct snd_uac2_chip *uac2 = prm->uac2;
905 	int i;
906 
907 	prm->ep_enabled = false;
908 
909 	for (i = 0; i < USB_XFERS; i++) {
910 		if (prm->ureq[i].req) {
911 			usb_ep_dequeue(ep, prm->ureq[i].req);
912 			usb_ep_free_request(ep, prm->ureq[i].req);
913 			prm->ureq[i].req = NULL;
914 		}
915 	}
916 
917 	if (usb_ep_disable(ep))
918 		dev_err(&uac2->pdev.dev,
919 			"%s:%d Error!\n", __func__, __LINE__);
920 }
921 
922 static int __init
923 afunc_bind(struct usb_configuration *cfg, struct usb_function *fn)
924 {
925 	struct audio_dev *agdev = func_to_agdev(fn);
926 	struct snd_uac2_chip *uac2 = &agdev->uac2;
927 	struct usb_composite_dev *cdev = cfg->cdev;
928 	struct usb_gadget *gadget = cdev->gadget;
929 	struct uac2_rtd_params *prm;
930 	int ret;
931 
932 	ret = usb_interface_id(cfg, fn);
933 	if (ret < 0) {
934 		dev_err(&uac2->pdev.dev,
935 			"%s:%d Error!\n", __func__, __LINE__);
936 		return ret;
937 	}
938 	std_ac_if_desc.bInterfaceNumber = ret;
939 	agdev->ac_intf = ret;
940 	agdev->ac_alt = 0;
941 
942 	ret = usb_interface_id(cfg, fn);
943 	if (ret < 0) {
944 		dev_err(&uac2->pdev.dev,
945 			"%s:%d Error!\n", __func__, __LINE__);
946 		return ret;
947 	}
948 	std_as_out_if0_desc.bInterfaceNumber = ret;
949 	std_as_out_if1_desc.bInterfaceNumber = ret;
950 	agdev->as_out_intf = ret;
951 	agdev->as_out_alt = 0;
952 
953 	ret = usb_interface_id(cfg, fn);
954 	if (ret < 0) {
955 		dev_err(&uac2->pdev.dev,
956 			"%s:%d Error!\n", __func__, __LINE__);
957 		return ret;
958 	}
959 	std_as_in_if0_desc.bInterfaceNumber = ret;
960 	std_as_in_if1_desc.bInterfaceNumber = ret;
961 	agdev->as_in_intf = ret;
962 	agdev->as_in_alt = 0;
963 
964 	agdev->out_ep = usb_ep_autoconfig(gadget, &fs_epout_desc);
965 	if (!agdev->out_ep) {
966 		dev_err(&uac2->pdev.dev,
967 			"%s:%d Error!\n", __func__, __LINE__);
968 		goto err;
969 	}
970 	agdev->out_ep->driver_data = agdev;
971 
972 	agdev->in_ep = usb_ep_autoconfig(gadget, &fs_epin_desc);
973 	if (!agdev->in_ep) {
974 		dev_err(&uac2->pdev.dev,
975 			"%s:%d Error!\n", __func__, __LINE__);
976 		goto err;
977 	}
978 	agdev->in_ep->driver_data = agdev;
979 
980 	uac2->p_prm.uac2 = uac2;
981 	uac2->c_prm.uac2 = uac2;
982 
983 	hs_epout_desc.bEndpointAddress = fs_epout_desc.bEndpointAddress;
984 	hs_epout_desc.wMaxPacketSize = fs_epout_desc.wMaxPacketSize;
985 	hs_epin_desc.bEndpointAddress = fs_epin_desc.bEndpointAddress;
986 	hs_epin_desc.wMaxPacketSize = fs_epin_desc.wMaxPacketSize;
987 
988 	ret = usb_assign_descriptors(fn, fs_audio_desc, hs_audio_desc, NULL);
989 	if (ret)
990 		goto err;
991 
992 	prm = &agdev->uac2.c_prm;
993 	prm->max_psize = hs_epout_desc.wMaxPacketSize;
994 	prm->rbuf = kzalloc(prm->max_psize * USB_XFERS, GFP_KERNEL);
995 	if (!prm->rbuf) {
996 		prm->max_psize = 0;
997 		goto err;
998 	}
999 
1000 	prm = &agdev->uac2.p_prm;
1001 	prm->max_psize = hs_epin_desc.wMaxPacketSize;
1002 	prm->rbuf = kzalloc(prm->max_psize * USB_XFERS, GFP_KERNEL);
1003 	if (!prm->rbuf) {
1004 		prm->max_psize = 0;
1005 		goto err;
1006 	}
1007 
1008 	ret = alsa_uac2_init(agdev);
1009 	if (ret)
1010 		goto err;
1011 	return 0;
1012 err:
1013 	kfree(agdev->uac2.p_prm.rbuf);
1014 	kfree(agdev->uac2.c_prm.rbuf);
1015 	usb_free_all_descriptors(fn);
1016 	if (agdev->in_ep)
1017 		agdev->in_ep->driver_data = NULL;
1018 	if (agdev->out_ep)
1019 		agdev->out_ep->driver_data = NULL;
1020 	return -EINVAL;
1021 }
1022 
1023 static void
1024 afunc_unbind(struct usb_configuration *cfg, struct usb_function *fn)
1025 {
1026 	struct audio_dev *agdev = func_to_agdev(fn);
1027 	struct uac2_rtd_params *prm;
1028 
1029 	alsa_uac2_exit(agdev);
1030 
1031 	prm = &agdev->uac2.p_prm;
1032 	kfree(prm->rbuf);
1033 
1034 	prm = &agdev->uac2.c_prm;
1035 	kfree(prm->rbuf);
1036 	usb_free_all_descriptors(fn);
1037 
1038 	if (agdev->in_ep)
1039 		agdev->in_ep->driver_data = NULL;
1040 	if (agdev->out_ep)
1041 		agdev->out_ep->driver_data = NULL;
1042 }
1043 
1044 static int
1045 afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt)
1046 {
1047 	struct usb_composite_dev *cdev = fn->config->cdev;
1048 	struct audio_dev *agdev = func_to_agdev(fn);
1049 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1050 	struct usb_gadget *gadget = cdev->gadget;
1051 	struct usb_request *req;
1052 	struct usb_ep *ep;
1053 	struct uac2_rtd_params *prm;
1054 	int i;
1055 
1056 	/* No i/f has more than 2 alt settings */
1057 	if (alt > 1) {
1058 		dev_err(&uac2->pdev.dev,
1059 			"%s:%d Error!\n", __func__, __LINE__);
1060 		return -EINVAL;
1061 	}
1062 
1063 	if (intf == agdev->ac_intf) {
1064 		/* Control I/f has only 1 AltSetting - 0 */
1065 		if (alt) {
1066 			dev_err(&uac2->pdev.dev,
1067 				"%s:%d Error!\n", __func__, __LINE__);
1068 			return -EINVAL;
1069 		}
1070 		return 0;
1071 	}
1072 
1073 	if (intf == agdev->as_out_intf) {
1074 		ep = agdev->out_ep;
1075 		prm = &uac2->c_prm;
1076 		config_ep_by_speed(gadget, fn, ep);
1077 		agdev->as_out_alt = alt;
1078 	} else if (intf == agdev->as_in_intf) {
1079 		ep = agdev->in_ep;
1080 		prm = &uac2->p_prm;
1081 		config_ep_by_speed(gadget, fn, ep);
1082 		agdev->as_in_alt = alt;
1083 	} else {
1084 		dev_err(&uac2->pdev.dev,
1085 			"%s:%d Error!\n", __func__, __LINE__);
1086 		return -EINVAL;
1087 	}
1088 
1089 	if (alt == 0) {
1090 		free_ep(prm, ep);
1091 		return 0;
1092 	}
1093 
1094 	prm->ep_enabled = true;
1095 	usb_ep_enable(ep);
1096 
1097 	for (i = 0; i < USB_XFERS; i++) {
1098 		if (prm->ureq[i].req) {
1099 			if (usb_ep_queue(ep, prm->ureq[i].req, GFP_ATOMIC))
1100 				dev_err(&uac2->pdev.dev, "%d Error!\n",
1101 					__LINE__);
1102 			continue;
1103 		}
1104 
1105 		req = usb_ep_alloc_request(ep, GFP_ATOMIC);
1106 		if (req == NULL) {
1107 			dev_err(&uac2->pdev.dev,
1108 				"%s:%d Error!\n", __func__, __LINE__);
1109 			return -EINVAL;
1110 		}
1111 
1112 		prm->ureq[i].req = req;
1113 		prm->ureq[i].pp = prm;
1114 
1115 		req->zero = 0;
1116 		req->context = &prm->ureq[i];
1117 		req->length = prm->max_psize;
1118 		req->complete =	agdev_iso_complete;
1119 		req->buf = prm->rbuf + i * req->length;
1120 
1121 		if (usb_ep_queue(ep, req, GFP_ATOMIC))
1122 			dev_err(&uac2->pdev.dev, "%d Error!\n", __LINE__);
1123 	}
1124 
1125 	return 0;
1126 }
1127 
1128 static int
1129 afunc_get_alt(struct usb_function *fn, unsigned intf)
1130 {
1131 	struct audio_dev *agdev = func_to_agdev(fn);
1132 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1133 
1134 	if (intf == agdev->ac_intf)
1135 		return agdev->ac_alt;
1136 	else if (intf == agdev->as_out_intf)
1137 		return agdev->as_out_alt;
1138 	else if (intf == agdev->as_in_intf)
1139 		return agdev->as_in_alt;
1140 	else
1141 		dev_err(&uac2->pdev.dev,
1142 			"%s:%d Invalid Interface %d!\n",
1143 			__func__, __LINE__, intf);
1144 
1145 	return -EINVAL;
1146 }
1147 
1148 static void
1149 afunc_disable(struct usb_function *fn)
1150 {
1151 	struct audio_dev *agdev = func_to_agdev(fn);
1152 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1153 
1154 	free_ep(&uac2->p_prm, agdev->in_ep);
1155 	agdev->as_in_alt = 0;
1156 
1157 	free_ep(&uac2->c_prm, agdev->out_ep);
1158 	agdev->as_out_alt = 0;
1159 }
1160 
1161 static int
1162 in_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1163 {
1164 	struct usb_request *req = fn->config->cdev->req;
1165 	struct audio_dev *agdev = func_to_agdev(fn);
1166 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1167 	u16 w_length = le16_to_cpu(cr->wLength);
1168 	u16 w_index = le16_to_cpu(cr->wIndex);
1169 	u16 w_value = le16_to_cpu(cr->wValue);
1170 	u8 entity_id = (w_index >> 8) & 0xff;
1171 	u8 control_selector = w_value >> 8;
1172 	int value = -EOPNOTSUPP;
1173 
1174 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
1175 		struct cntrl_cur_lay3 c;
1176 
1177 		if (entity_id == USB_IN_CLK_ID)
1178 			c.dCUR = p_srate;
1179 		else if (entity_id == USB_OUT_CLK_ID)
1180 			c.dCUR = c_srate;
1181 
1182 		value = min_t(unsigned, w_length, sizeof c);
1183 		memcpy(req->buf, &c, value);
1184 	} else if (control_selector == UAC2_CS_CONTROL_CLOCK_VALID) {
1185 		*(u8 *)req->buf = 1;
1186 		value = min_t(unsigned, w_length, 1);
1187 	} else {
1188 		dev_err(&uac2->pdev.dev,
1189 			"%s:%d control_selector=%d TODO!\n",
1190 			__func__, __LINE__, control_selector);
1191 	}
1192 
1193 	return value;
1194 }
1195 
1196 static int
1197 in_rq_range(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1198 {
1199 	struct usb_request *req = fn->config->cdev->req;
1200 	struct audio_dev *agdev = func_to_agdev(fn);
1201 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1202 	u16 w_length = le16_to_cpu(cr->wLength);
1203 	u16 w_index = le16_to_cpu(cr->wIndex);
1204 	u16 w_value = le16_to_cpu(cr->wValue);
1205 	u8 entity_id = (w_index >> 8) & 0xff;
1206 	u8 control_selector = w_value >> 8;
1207 	struct cntrl_range_lay3 r;
1208 	int value = -EOPNOTSUPP;
1209 
1210 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ) {
1211 		if (entity_id == USB_IN_CLK_ID)
1212 			r.dMIN = p_srate;
1213 		else if (entity_id == USB_OUT_CLK_ID)
1214 			r.dMIN = c_srate;
1215 		else
1216 			return -EOPNOTSUPP;
1217 
1218 		r.dMAX = r.dMIN;
1219 		r.dRES = 0;
1220 		r.wNumSubRanges = 1;
1221 
1222 		value = min_t(unsigned, w_length, sizeof r);
1223 		memcpy(req->buf, &r, value);
1224 	} else {
1225 		dev_err(&uac2->pdev.dev,
1226 			"%s:%d control_selector=%d TODO!\n",
1227 			__func__, __LINE__, control_selector);
1228 	}
1229 
1230 	return value;
1231 }
1232 
1233 static int
1234 ac_rq_in(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1235 {
1236 	if (cr->bRequest == UAC2_CS_CUR)
1237 		return in_rq_cur(fn, cr);
1238 	else if (cr->bRequest == UAC2_CS_RANGE)
1239 		return in_rq_range(fn, cr);
1240 	else
1241 		return -EOPNOTSUPP;
1242 }
1243 
1244 static int
1245 out_rq_cur(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1246 {
1247 	u16 w_length = le16_to_cpu(cr->wLength);
1248 	u16 w_value = le16_to_cpu(cr->wValue);
1249 	u8 control_selector = w_value >> 8;
1250 
1251 	if (control_selector == UAC2_CS_CONTROL_SAM_FREQ)
1252 		return w_length;
1253 
1254 	return -EOPNOTSUPP;
1255 }
1256 
1257 static int
1258 setup_rq_inf(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1259 {
1260 	struct audio_dev *agdev = func_to_agdev(fn);
1261 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1262 	u16 w_index = le16_to_cpu(cr->wIndex);
1263 	u8 intf = w_index & 0xff;
1264 
1265 	if (intf != agdev->ac_intf) {
1266 		dev_err(&uac2->pdev.dev,
1267 			"%s:%d Error!\n", __func__, __LINE__);
1268 		return -EOPNOTSUPP;
1269 	}
1270 
1271 	if (cr->bRequestType & USB_DIR_IN)
1272 		return ac_rq_in(fn, cr);
1273 	else if (cr->bRequest == UAC2_CS_CUR)
1274 		return out_rq_cur(fn, cr);
1275 
1276 	return -EOPNOTSUPP;
1277 }
1278 
1279 static int
1280 afunc_setup(struct usb_function *fn, const struct usb_ctrlrequest *cr)
1281 {
1282 	struct usb_composite_dev *cdev = fn->config->cdev;
1283 	struct audio_dev *agdev = func_to_agdev(fn);
1284 	struct snd_uac2_chip *uac2 = &agdev->uac2;
1285 	struct usb_request *req = cdev->req;
1286 	u16 w_length = le16_to_cpu(cr->wLength);
1287 	int value = -EOPNOTSUPP;
1288 
1289 	/* Only Class specific requests are supposed to reach here */
1290 	if ((cr->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
1291 		return -EOPNOTSUPP;
1292 
1293 	if ((cr->bRequestType & USB_RECIP_MASK) == USB_RECIP_INTERFACE)
1294 		value = setup_rq_inf(fn, cr);
1295 	else
1296 		dev_err(&uac2->pdev.dev, "%s:%d Error!\n", __func__, __LINE__);
1297 
1298 	if (value >= 0) {
1299 		req->length = value;
1300 		req->zero = value < w_length;
1301 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1302 		if (value < 0) {
1303 			dev_err(&uac2->pdev.dev,
1304 				"%s:%d Error!\n", __func__, __LINE__);
1305 			req->status = 0;
1306 		}
1307 	}
1308 
1309 	return value;
1310 }
1311 
1312 static int audio_bind_config(struct usb_configuration *cfg)
1313 {
1314 	int res;
1315 
1316 	agdev_g = kzalloc(sizeof *agdev_g, GFP_KERNEL);
1317 	if (agdev_g == NULL)
1318 		return -ENOMEM;
1319 
1320 	res = usb_string_ids_tab(cfg->cdev, strings_fn);
1321 	if (res)
1322 		return res;
1323 	iad_desc.iFunction = strings_fn[STR_ASSOC].id;
1324 	std_ac_if_desc.iInterface = strings_fn[STR_IF_CTRL].id;
1325 	in_clk_src_desc.iClockSource = strings_fn[STR_CLKSRC_IN].id;
1326 	out_clk_src_desc.iClockSource = strings_fn[STR_CLKSRC_OUT].id;
1327 	usb_out_it_desc.iTerminal = strings_fn[STR_USB_IT].id;
1328 	io_in_it_desc.iTerminal = strings_fn[STR_IO_IT].id;
1329 	usb_in_ot_desc.iTerminal = strings_fn[STR_USB_OT].id;
1330 	io_out_ot_desc.iTerminal = strings_fn[STR_IO_OT].id;
1331 	std_as_out_if0_desc.iInterface = strings_fn[STR_AS_OUT_ALT0].id;
1332 	std_as_out_if1_desc.iInterface = strings_fn[STR_AS_OUT_ALT1].id;
1333 	std_as_in_if0_desc.iInterface = strings_fn[STR_AS_IN_ALT0].id;
1334 	std_as_in_if1_desc.iInterface = strings_fn[STR_AS_IN_ALT1].id;
1335 
1336 	agdev_g->func.name = "uac2_func";
1337 	agdev_g->func.strings = fn_strings;
1338 	agdev_g->func.bind = afunc_bind;
1339 	agdev_g->func.unbind = afunc_unbind;
1340 	agdev_g->func.set_alt = afunc_set_alt;
1341 	agdev_g->func.get_alt = afunc_get_alt;
1342 	agdev_g->func.disable = afunc_disable;
1343 	agdev_g->func.setup = afunc_setup;
1344 
1345 	/* Initialize the configurable parameters */
1346 	usb_out_it_desc.bNrChannels = num_channels(c_chmask);
1347 	usb_out_it_desc.bmChannelConfig = cpu_to_le32(c_chmask);
1348 	io_in_it_desc.bNrChannels = num_channels(p_chmask);
1349 	io_in_it_desc.bmChannelConfig = cpu_to_le32(p_chmask);
1350 	as_out_hdr_desc.bNrChannels = num_channels(c_chmask);
1351 	as_out_hdr_desc.bmChannelConfig = cpu_to_le32(c_chmask);
1352 	as_in_hdr_desc.bNrChannels = num_channels(p_chmask);
1353 	as_in_hdr_desc.bmChannelConfig = cpu_to_le32(p_chmask);
1354 	as_out_fmt1_desc.bSubslotSize = c_ssize;
1355 	as_out_fmt1_desc.bBitResolution = c_ssize * 8;
1356 	as_in_fmt1_desc.bSubslotSize = p_ssize;
1357 	as_in_fmt1_desc.bBitResolution = p_ssize * 8;
1358 
1359 	snprintf(clksrc_in, sizeof(clksrc_in), "%uHz", p_srate);
1360 	snprintf(clksrc_out, sizeof(clksrc_out), "%uHz", c_srate);
1361 
1362 	res = usb_add_function(cfg, &agdev_g->func);
1363 	if (res < 0)
1364 		kfree(agdev_g);
1365 
1366 	return res;
1367 }
1368 
1369 static void
1370 uac2_unbind_config(struct usb_configuration *cfg)
1371 {
1372 	kfree(agdev_g);
1373 	agdev_g = NULL;
1374 }
1375