1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * f_uac1.c -- USB Audio Class 1.0 Function (using u_audio API)
4 *
5 * Copyright (C) 2016 Ruslan Bilovol <ruslan.bilovol@gmail.com>
6 *
7 * This driver doesn't expect any real Audio codec to be present
8 * on the device - the audio streams are simply sinked to and
9 * sourced from a virtual ALSA sound card created.
10 *
11 * This file is based on f_uac1.c which is
12 *   Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
13 *   Copyright (C) 2008 Analog Devices, Inc
14 */
15
16#include <linux/usb/audio.h>
17#include <linux/module.h>
18
19#include "u_audio.h"
20#include "u_uac1.h"
21
22/* UAC1 spec: 3.7.2.3 Audio Channel Cluster Format */
23#define UAC1_CHANNEL_MASK 0x0FFF
24
25struct f_uac1 {
26	struct g_audio g_audio;
27	u8 ac_intf, as_in_intf, as_out_intf;
28	u8 ac_alt, as_in_alt, as_out_alt;	/* needed for get_alt() */
29};
30
31static inline struct f_uac1 *func_to_uac1(struct usb_function *f)
32{
33	return container_of(f, struct f_uac1, g_audio.func);
34}
35
36static inline struct f_uac1_opts *g_audio_to_uac1_opts(struct g_audio *audio)
37{
38	return container_of(audio->func.fi, struct f_uac1_opts, func_inst);
39}
40
41/*
42 * DESCRIPTORS ... most are static, but strings and full
43 * configuration descriptors are built on demand.
44 */
45
46/*
47 * We have three interfaces - one AudioControl and two AudioStreaming
48 *
49 * The driver implements a simple UAC_1 topology.
50 * USB-OUT -> IT_1 -> OT_2 -> ALSA_Capture
51 * ALSA_Playback -> IT_3 -> OT_4 -> USB-IN
52 */
53#define F_AUDIO_AC_INTERFACE		0
54#define F_AUDIO_AS_OUT_INTERFACE	1
55#define F_AUDIO_AS_IN_INTERFACE		2
56/* Number of streaming interfaces */
57#define F_AUDIO_NUM_INTERFACES		2
58
59/* B.3.1  Standard AC Interface Descriptor */
60static struct usb_interface_descriptor ac_interface_desc = {
61	.bLength =		USB_DT_INTERFACE_SIZE,
62	.bDescriptorType =	USB_DT_INTERFACE,
63	.bNumEndpoints =	0,
64	.bInterfaceClass =	USB_CLASS_AUDIO,
65	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOCONTROL,
66};
67
68/*
69 * The number of AudioStreaming and MIDIStreaming interfaces
70 * in the Audio Interface Collection
71 */
72DECLARE_UAC_AC_HEADER_DESCRIPTOR(2);
73
74#define UAC_DT_AC_HEADER_LENGTH	UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
75/* 2 input terminals and 2 output terminals */
76#define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH \
77	+ 2*UAC_DT_INPUT_TERMINAL_SIZE + 2*UAC_DT_OUTPUT_TERMINAL_SIZE)
78/* B.3.2  Class-Specific AC Interface Descriptor */
79static struct uac1_ac_header_descriptor_2 ac_header_desc = {
80	.bLength =		UAC_DT_AC_HEADER_LENGTH,
81	.bDescriptorType =	USB_DT_CS_INTERFACE,
82	.bDescriptorSubtype =	UAC_HEADER,
83	.bcdADC =		cpu_to_le16(0x0100),
84	.wTotalLength =		cpu_to_le16(UAC_DT_TOTAL_LENGTH),
85	.bInCollection =	F_AUDIO_NUM_INTERFACES,
86	.baInterfaceNr = {
87	/* Interface number of the AudioStream interfaces */
88		[0] =		1,
89		[1] =		2,
90	}
91};
92
93#define USB_OUT_IT_ID	1
94static struct uac_input_terminal_descriptor usb_out_it_desc = {
95	.bLength =		UAC_DT_INPUT_TERMINAL_SIZE,
96	.bDescriptorType =	USB_DT_CS_INTERFACE,
97	.bDescriptorSubtype =	UAC_INPUT_TERMINAL,
98	.bTerminalID =		USB_OUT_IT_ID,
99	.wTerminalType =	cpu_to_le16(UAC_TERMINAL_STREAMING),
100	.bAssocTerminal =	0,
101	.wChannelConfig =	cpu_to_le16(0x3),
102};
103
104#define IO_OUT_OT_ID	2
105static struct uac1_output_terminal_descriptor io_out_ot_desc = {
106	.bLength		= UAC_DT_OUTPUT_TERMINAL_SIZE,
107	.bDescriptorType	= USB_DT_CS_INTERFACE,
108	.bDescriptorSubtype	= UAC_OUTPUT_TERMINAL,
109	.bTerminalID		= IO_OUT_OT_ID,
110	.wTerminalType		= cpu_to_le16(UAC_OUTPUT_TERMINAL_SPEAKER),
111	.bAssocTerminal		= 0,
112	.bSourceID		= USB_OUT_IT_ID,
113};
114
115#define IO_IN_IT_ID	3
116static struct uac_input_terminal_descriptor io_in_it_desc = {
117	.bLength		= UAC_DT_INPUT_TERMINAL_SIZE,
118	.bDescriptorType	= USB_DT_CS_INTERFACE,
119	.bDescriptorSubtype	= UAC_INPUT_TERMINAL,
120	.bTerminalID		= IO_IN_IT_ID,
121	.wTerminalType		= cpu_to_le16(UAC_INPUT_TERMINAL_MICROPHONE),
122	.bAssocTerminal		= 0,
123	.wChannelConfig		= cpu_to_le16(0x3),
124};
125
126#define USB_IN_OT_ID	4
127static struct uac1_output_terminal_descriptor usb_in_ot_desc = {
128	.bLength =		UAC_DT_OUTPUT_TERMINAL_SIZE,
129	.bDescriptorType =	USB_DT_CS_INTERFACE,
130	.bDescriptorSubtype =	UAC_OUTPUT_TERMINAL,
131	.bTerminalID =		USB_IN_OT_ID,
132	.wTerminalType =	cpu_to_le16(UAC_TERMINAL_STREAMING),
133	.bAssocTerminal =	0,
134	.bSourceID =		IO_IN_IT_ID,
135};
136
137/* B.4.1  Standard AS Interface Descriptor */
138static struct usb_interface_descriptor as_out_interface_alt_0_desc = {
139	.bLength =		USB_DT_INTERFACE_SIZE,
140	.bDescriptorType =	USB_DT_INTERFACE,
141	.bAlternateSetting =	0,
142	.bNumEndpoints =	0,
143	.bInterfaceClass =	USB_CLASS_AUDIO,
144	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
145};
146
147static struct usb_interface_descriptor as_out_interface_alt_1_desc = {
148	.bLength =		USB_DT_INTERFACE_SIZE,
149	.bDescriptorType =	USB_DT_INTERFACE,
150	.bAlternateSetting =	1,
151	.bNumEndpoints =	1,
152	.bInterfaceClass =	USB_CLASS_AUDIO,
153	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
154};
155
156static struct usb_interface_descriptor as_in_interface_alt_0_desc = {
157	.bLength =		USB_DT_INTERFACE_SIZE,
158	.bDescriptorType =	USB_DT_INTERFACE,
159	.bAlternateSetting =	0,
160	.bNumEndpoints =	0,
161	.bInterfaceClass =	USB_CLASS_AUDIO,
162	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
163};
164
165static struct usb_interface_descriptor as_in_interface_alt_1_desc = {
166	.bLength =		USB_DT_INTERFACE_SIZE,
167	.bDescriptorType =	USB_DT_INTERFACE,
168	.bAlternateSetting =	1,
169	.bNumEndpoints =	1,
170	.bInterfaceClass =	USB_CLASS_AUDIO,
171	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
172};
173
174/* B.4.2  Class-Specific AS Interface Descriptor */
175static struct uac1_as_header_descriptor as_out_header_desc = {
176	.bLength =		UAC_DT_AS_HEADER_SIZE,
177	.bDescriptorType =	USB_DT_CS_INTERFACE,
178	.bDescriptorSubtype =	UAC_AS_GENERAL,
179	.bTerminalLink =	USB_OUT_IT_ID,
180	.bDelay =		1,
181	.wFormatTag =		cpu_to_le16(UAC_FORMAT_TYPE_I_PCM),
182};
183
184static struct uac1_as_header_descriptor as_in_header_desc = {
185	.bLength =		UAC_DT_AS_HEADER_SIZE,
186	.bDescriptorType =	USB_DT_CS_INTERFACE,
187	.bDescriptorSubtype =	UAC_AS_GENERAL,
188	.bTerminalLink =	USB_IN_OT_ID,
189	.bDelay =		1,
190	.wFormatTag =		cpu_to_le16(UAC_FORMAT_TYPE_I_PCM),
191};
192
193DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
194
195static struct uac_format_type_i_discrete_descriptor_1 as_out_type_i_desc = {
196	.bLength =		UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
197	.bDescriptorType =	USB_DT_CS_INTERFACE,
198	.bDescriptorSubtype =	UAC_FORMAT_TYPE,
199	.bFormatType =		UAC_FORMAT_TYPE_I,
200	.bSubframeSize =	2,
201	.bBitResolution =	16,
202	.bSamFreqType =		1,
203};
204
205/* Standard ISO OUT Endpoint Descriptor */
206static struct usb_endpoint_descriptor as_out_ep_desc  = {
207	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
208	.bDescriptorType =	USB_DT_ENDPOINT,
209	.bEndpointAddress =	USB_DIR_OUT,
210	.bmAttributes =		USB_ENDPOINT_SYNC_ADAPTIVE
211				| USB_ENDPOINT_XFER_ISOC,
212	.wMaxPacketSize	=	cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
213	.bInterval =		4,
214};
215
216/* Class-specific AS ISO OUT Endpoint Descriptor */
217static struct uac_iso_endpoint_descriptor as_iso_out_desc = {
218	.bLength =		UAC_ISO_ENDPOINT_DESC_SIZE,
219	.bDescriptorType =	USB_DT_CS_ENDPOINT,
220	.bDescriptorSubtype =	UAC_EP_GENERAL,
221	.bmAttributes =		1,
222	.bLockDelayUnits =	1,
223	.wLockDelay =		cpu_to_le16(1),
224};
225
226static struct uac_format_type_i_discrete_descriptor_1 as_in_type_i_desc = {
227	.bLength =		UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
228	.bDescriptorType =	USB_DT_CS_INTERFACE,
229	.bDescriptorSubtype =	UAC_FORMAT_TYPE,
230	.bFormatType =		UAC_FORMAT_TYPE_I,
231	.bSubframeSize =	2,
232	.bBitResolution =	16,
233	.bSamFreqType =		1,
234};
235
236/* Standard ISO OUT Endpoint Descriptor */
237static struct usb_endpoint_descriptor as_in_ep_desc  = {
238	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
239	.bDescriptorType =	USB_DT_ENDPOINT,
240	.bEndpointAddress =	USB_DIR_IN,
241	.bmAttributes =		USB_ENDPOINT_SYNC_ASYNC
242				| USB_ENDPOINT_XFER_ISOC,
243	.wMaxPacketSize	=	cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
244	.bInterval =		4,
245};
246
247/* Class-specific AS ISO OUT Endpoint Descriptor */
248static struct uac_iso_endpoint_descriptor as_iso_in_desc = {
249	.bLength =		UAC_ISO_ENDPOINT_DESC_SIZE,
250	.bDescriptorType =	USB_DT_CS_ENDPOINT,
251	.bDescriptorSubtype =	UAC_EP_GENERAL,
252	.bmAttributes =		1,
253	.bLockDelayUnits =	0,
254	.wLockDelay =		0,
255};
256
257static struct usb_descriptor_header *f_audio_desc[] = {
258	(struct usb_descriptor_header *)&ac_interface_desc,
259	(struct usb_descriptor_header *)&ac_header_desc,
260
261	(struct usb_descriptor_header *)&usb_out_it_desc,
262	(struct usb_descriptor_header *)&io_out_ot_desc,
263	(struct usb_descriptor_header *)&io_in_it_desc,
264	(struct usb_descriptor_header *)&usb_in_ot_desc,
265
266	(struct usb_descriptor_header *)&as_out_interface_alt_0_desc,
267	(struct usb_descriptor_header *)&as_out_interface_alt_1_desc,
268	(struct usb_descriptor_header *)&as_out_header_desc,
269
270	(struct usb_descriptor_header *)&as_out_type_i_desc,
271
272	(struct usb_descriptor_header *)&as_out_ep_desc,
273	(struct usb_descriptor_header *)&as_iso_out_desc,
274
275	(struct usb_descriptor_header *)&as_in_interface_alt_0_desc,
276	(struct usb_descriptor_header *)&as_in_interface_alt_1_desc,
277	(struct usb_descriptor_header *)&as_in_header_desc,
278
279	(struct usb_descriptor_header *)&as_in_type_i_desc,
280
281	(struct usb_descriptor_header *)&as_in_ep_desc,
282	(struct usb_descriptor_header *)&as_iso_in_desc,
283	NULL,
284};
285
286enum {
287	STR_AC_IF,
288	STR_USB_OUT_IT,
289	STR_USB_OUT_IT_CH_NAMES,
290	STR_IO_OUT_OT,
291	STR_IO_IN_IT,
292	STR_IO_IN_IT_CH_NAMES,
293	STR_USB_IN_OT,
294	STR_AS_OUT_IF_ALT0,
295	STR_AS_OUT_IF_ALT1,
296	STR_AS_IN_IF_ALT0,
297	STR_AS_IN_IF_ALT1,
298};
299
300static struct usb_string strings_uac1[] = {
301	[STR_AC_IF].s = "AC Interface",
302	[STR_USB_OUT_IT].s = "Playback Input terminal",
303	[STR_USB_OUT_IT_CH_NAMES].s = "Playback Channels",
304	[STR_IO_OUT_OT].s = "Playback Output terminal",
305	[STR_IO_IN_IT].s = "Capture Input terminal",
306	[STR_IO_IN_IT_CH_NAMES].s = "Capture Channels",
307	[STR_USB_IN_OT].s = "Capture Output terminal",
308	[STR_AS_OUT_IF_ALT0].s = "Playback Inactive",
309	[STR_AS_OUT_IF_ALT1].s = "Playback Active",
310	[STR_AS_IN_IF_ALT0].s = "Capture Inactive",
311	[STR_AS_IN_IF_ALT1].s = "Capture Active",
312	{ },
313};
314
315static struct usb_gadget_strings str_uac1 = {
316	.language = 0x0409,	/* en-us */
317	.strings = strings_uac1,
318};
319
320static struct usb_gadget_strings *uac1_strings[] = {
321	&str_uac1,
322	NULL,
323};
324
325/*
326 * This function is an ALSA sound card following USB Audio Class Spec 1.0.
327 */
328
329static int audio_set_endpoint_req(struct usb_function *f,
330		const struct usb_ctrlrequest *ctrl)
331{
332	struct usb_composite_dev *cdev = f->config->cdev;
333	int			value = -EOPNOTSUPP;
334	u16			ep = le16_to_cpu(ctrl->wIndex);
335	u16			len = le16_to_cpu(ctrl->wLength);
336	u16			w_value = le16_to_cpu(ctrl->wValue);
337
338	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
339			ctrl->bRequest, w_value, len, ep);
340
341	switch (ctrl->bRequest) {
342	case UAC_SET_CUR:
343		value = len;
344		break;
345
346	case UAC_SET_MIN:
347		break;
348
349	case UAC_SET_MAX:
350		break;
351
352	case UAC_SET_RES:
353		break;
354
355	case UAC_SET_MEM:
356		break;
357
358	default:
359		break;
360	}
361
362	return value;
363}
364
365static int audio_get_endpoint_req(struct usb_function *f,
366		const struct usb_ctrlrequest *ctrl)
367{
368	struct usb_composite_dev *cdev = f->config->cdev;
369	int value = -EOPNOTSUPP;
370	u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
371	u16 len = le16_to_cpu(ctrl->wLength);
372	u16 w_value = le16_to_cpu(ctrl->wValue);
373
374	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
375			ctrl->bRequest, w_value, len, ep);
376
377	switch (ctrl->bRequest) {
378	case UAC_GET_CUR:
379	case UAC_GET_MIN:
380	case UAC_GET_MAX:
381	case UAC_GET_RES:
382		value = len;
383		break;
384	case UAC_GET_MEM:
385		break;
386	default:
387		break;
388	}
389
390	return value;
391}
392
393static int
394f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
395{
396	struct usb_composite_dev *cdev = f->config->cdev;
397	struct usb_request	*req = cdev->req;
398	int			value = -EOPNOTSUPP;
399	u16			w_index = le16_to_cpu(ctrl->wIndex);
400	u16			w_value = le16_to_cpu(ctrl->wValue);
401	u16			w_length = le16_to_cpu(ctrl->wLength);
402
403	/* composite driver infrastructure handles everything; interface
404	 * activation uses set_alt().
405	 */
406	switch (ctrl->bRequestType) {
407	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
408		value = audio_set_endpoint_req(f, ctrl);
409		break;
410
411	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
412		value = audio_get_endpoint_req(f, ctrl);
413		break;
414
415	default:
416		ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
417			ctrl->bRequestType, ctrl->bRequest,
418			w_value, w_index, w_length);
419	}
420
421	/* respond with data transfer or status phase? */
422	if (value >= 0) {
423		DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
424			ctrl->bRequestType, ctrl->bRequest,
425			w_value, w_index, w_length);
426		req->zero = 0;
427		req->length = value;
428		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
429		if (value < 0)
430			ERROR(cdev, "audio response on err %d\n", value);
431	}
432
433	/* device either stalls (value < 0) or reports success */
434	return value;
435}
436
437static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
438{
439	struct usb_composite_dev *cdev = f->config->cdev;
440	struct usb_gadget *gadget = cdev->gadget;
441	struct device *dev = &gadget->dev;
442	struct f_uac1 *uac1 = func_to_uac1(f);
443	int ret = 0;
444
445	/* No i/f has more than 2 alt settings */
446	if (alt > 1) {
447		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
448		return -EINVAL;
449	}
450
451	if (intf == uac1->ac_intf) {
452		/* Control I/f has only 1 AltSetting - 0 */
453		if (alt) {
454			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
455			return -EINVAL;
456		}
457		return 0;
458	}
459
460	if (intf == uac1->as_out_intf) {
461		uac1->as_out_alt = alt;
462
463		if (alt)
464			ret = u_audio_start_capture(&uac1->g_audio);
465		else
466			u_audio_stop_capture(&uac1->g_audio);
467	} else if (intf == uac1->as_in_intf) {
468		uac1->as_in_alt = alt;
469
470		if (alt)
471			ret = u_audio_start_playback(&uac1->g_audio);
472		else
473			u_audio_stop_playback(&uac1->g_audio);
474	} else {
475		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
476		return -EINVAL;
477	}
478
479	return ret;
480}
481
482static int f_audio_get_alt(struct usb_function *f, unsigned intf)
483{
484	struct usb_composite_dev *cdev = f->config->cdev;
485	struct usb_gadget *gadget = cdev->gadget;
486	struct device *dev = &gadget->dev;
487	struct f_uac1 *uac1 = func_to_uac1(f);
488
489	if (intf == uac1->ac_intf)
490		return uac1->ac_alt;
491	else if (intf == uac1->as_out_intf)
492		return uac1->as_out_alt;
493	else if (intf == uac1->as_in_intf)
494		return uac1->as_in_alt;
495	else
496		dev_err(dev, "%s:%d Invalid Interface %d!\n",
497			__func__, __LINE__, intf);
498
499	return -EINVAL;
500}
501
502
503static void f_audio_disable(struct usb_function *f)
504{
505	struct f_uac1 *uac1 = func_to_uac1(f);
506
507	uac1->as_out_alt = 0;
508	uac1->as_in_alt = 0;
509
510	u_audio_stop_playback(&uac1->g_audio);
511	u_audio_stop_capture(&uac1->g_audio);
512}
513
514/*-------------------------------------------------------------------------*/
515
516static int f_audio_validate_opts(struct g_audio *audio, struct device *dev)
517{
518	struct f_uac1_opts *opts = g_audio_to_uac1_opts(audio);
519
520	if (!opts->p_chmask && !opts->c_chmask) {
521		dev_err(dev, "Error: no playback and capture channels\n");
522		return -EINVAL;
523	} else if (opts->p_chmask & ~UAC1_CHANNEL_MASK) {
524		dev_err(dev, "Error: unsupported playback channels mask\n");
525		return -EINVAL;
526	} else if (opts->c_chmask & ~UAC1_CHANNEL_MASK) {
527		dev_err(dev, "Error: unsupported capture channels mask\n");
528		return -EINVAL;
529	} else if ((opts->p_ssize < 1) || (opts->p_ssize > 4)) {
530		dev_err(dev, "Error: incorrect playback sample size\n");
531		return -EINVAL;
532	} else if ((opts->c_ssize < 1) || (opts->c_ssize > 4)) {
533		dev_err(dev, "Error: incorrect capture sample size\n");
534		return -EINVAL;
535	} else if (!opts->p_srate) {
536		dev_err(dev, "Error: incorrect playback sampling rate\n");
537		return -EINVAL;
538	} else if (!opts->c_srate) {
539		dev_err(dev, "Error: incorrect capture sampling rate\n");
540		return -EINVAL;
541	}
542
543	return 0;
544}
545
546/* audio function driver setup/binding */
547static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
548{
549	struct usb_composite_dev	*cdev = c->cdev;
550	struct usb_gadget		*gadget = cdev->gadget;
551	struct device			*dev = &gadget->dev;
552	struct f_uac1			*uac1 = func_to_uac1(f);
553	struct g_audio			*audio = func_to_g_audio(f);
554	struct f_uac1_opts		*audio_opts;
555	struct usb_ep			*ep = NULL;
556	struct usb_string		*us;
557	u8				*sam_freq;
558	int				rate;
559	int				status;
560
561	status = f_audio_validate_opts(audio, dev);
562	if (status)
563		return status;
564
565	audio_opts = container_of(f->fi, struct f_uac1_opts, func_inst);
566
567	us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
568	if (IS_ERR(us))
569		return PTR_ERR(us);
570	ac_interface_desc.iInterface = us[STR_AC_IF].id;
571	usb_out_it_desc.iTerminal = us[STR_USB_OUT_IT].id;
572	usb_out_it_desc.iChannelNames = us[STR_USB_OUT_IT_CH_NAMES].id;
573	io_out_ot_desc.iTerminal = us[STR_IO_OUT_OT].id;
574	as_out_interface_alt_0_desc.iInterface = us[STR_AS_OUT_IF_ALT0].id;
575	as_out_interface_alt_1_desc.iInterface = us[STR_AS_OUT_IF_ALT1].id;
576	io_in_it_desc.iTerminal = us[STR_IO_IN_IT].id;
577	io_in_it_desc.iChannelNames = us[STR_IO_IN_IT_CH_NAMES].id;
578	usb_in_ot_desc.iTerminal = us[STR_USB_IN_OT].id;
579	as_in_interface_alt_0_desc.iInterface = us[STR_AS_IN_IF_ALT0].id;
580	as_in_interface_alt_1_desc.iInterface = us[STR_AS_IN_IF_ALT1].id;
581
582	/* Set channel numbers */
583	usb_out_it_desc.bNrChannels = num_channels(audio_opts->c_chmask);
584	usb_out_it_desc.wChannelConfig = cpu_to_le16(audio_opts->c_chmask);
585	as_out_type_i_desc.bNrChannels = num_channels(audio_opts->c_chmask);
586	as_out_type_i_desc.bSubframeSize = audio_opts->c_ssize;
587	as_out_type_i_desc.bBitResolution = audio_opts->c_ssize * 8;
588	io_in_it_desc.bNrChannels = num_channels(audio_opts->p_chmask);
589	io_in_it_desc.wChannelConfig = cpu_to_le16(audio_opts->p_chmask);
590	as_in_type_i_desc.bNrChannels = num_channels(audio_opts->p_chmask);
591	as_in_type_i_desc.bSubframeSize = audio_opts->p_ssize;
592	as_in_type_i_desc.bBitResolution = audio_opts->p_ssize * 8;
593
594	/* Set sample rates */
595	rate = audio_opts->c_srate;
596	sam_freq = as_out_type_i_desc.tSamFreq[0];
597	memcpy(sam_freq, &rate, 3);
598	rate = audio_opts->p_srate;
599	sam_freq = as_in_type_i_desc.tSamFreq[0];
600	memcpy(sam_freq, &rate, 3);
601
602	/* allocate instance-specific interface IDs, and patch descriptors */
603	status = usb_interface_id(c, f);
604	if (status < 0)
605		goto fail;
606	ac_interface_desc.bInterfaceNumber = status;
607	uac1->ac_intf = status;
608	uac1->ac_alt = 0;
609
610	status = usb_interface_id(c, f);
611	if (status < 0)
612		goto fail;
613	as_out_interface_alt_0_desc.bInterfaceNumber = status;
614	as_out_interface_alt_1_desc.bInterfaceNumber = status;
615	ac_header_desc.baInterfaceNr[0] = status;
616	uac1->as_out_intf = status;
617	uac1->as_out_alt = 0;
618
619	status = usb_interface_id(c, f);
620	if (status < 0)
621		goto fail;
622	as_in_interface_alt_0_desc.bInterfaceNumber = status;
623	as_in_interface_alt_1_desc.bInterfaceNumber = status;
624	ac_header_desc.baInterfaceNr[1] = status;
625	uac1->as_in_intf = status;
626	uac1->as_in_alt = 0;
627
628	audio->gadget = gadget;
629
630	status = -ENODEV;
631
632	/* allocate instance-specific endpoints */
633	ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
634	if (!ep)
635		goto fail;
636	audio->out_ep = ep;
637	audio->out_ep->desc = &as_out_ep_desc;
638
639	ep = usb_ep_autoconfig(cdev->gadget, &as_in_ep_desc);
640	if (!ep)
641		goto fail;
642	audio->in_ep = ep;
643	audio->in_ep->desc = &as_in_ep_desc;
644
645	/* copy descriptors, and track endpoint copies */
646	status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL,
647					NULL);
648	if (status)
649		goto fail;
650
651	audio->out_ep_maxpsize = le16_to_cpu(as_out_ep_desc.wMaxPacketSize);
652	audio->in_ep_maxpsize = le16_to_cpu(as_in_ep_desc.wMaxPacketSize);
653	audio->params.c_chmask = audio_opts->c_chmask;
654	audio->params.c_srate = audio_opts->c_srate;
655	audio->params.c_ssize = audio_opts->c_ssize;
656	audio->params.p_chmask = audio_opts->p_chmask;
657	audio->params.p_srate = audio_opts->p_srate;
658	audio->params.p_ssize = audio_opts->p_ssize;
659	audio->params.req_number = audio_opts->req_number;
660
661	status = g_audio_setup(audio, "UAC1_PCM", "UAC1_Gadget");
662	if (status)
663		goto err_card_register;
664
665	return 0;
666
667err_card_register:
668	usb_free_all_descriptors(f);
669fail:
670	return status;
671}
672
673/*-------------------------------------------------------------------------*/
674
675static inline struct f_uac1_opts *to_f_uac1_opts(struct config_item *item)
676{
677	return container_of(to_config_group(item), struct f_uac1_opts,
678			    func_inst.group);
679}
680
681static void f_uac1_attr_release(struct config_item *item)
682{
683	struct f_uac1_opts *opts = to_f_uac1_opts(item);
684
685	usb_put_function_instance(&opts->func_inst);
686}
687
688static struct configfs_item_operations f_uac1_item_ops = {
689	.release	= f_uac1_attr_release,
690};
691
692#define UAC1_ATTRIBUTE(name)						\
693static ssize_t f_uac1_opts_##name##_show(				\
694					  struct config_item *item,	\
695					  char *page)			\
696{									\
697	struct f_uac1_opts *opts = to_f_uac1_opts(item);		\
698	int result;							\
699									\
700	mutex_lock(&opts->lock);					\
701	result = sprintf(page, "%u\n", opts->name);			\
702	mutex_unlock(&opts->lock);					\
703									\
704	return result;							\
705}									\
706									\
707static ssize_t f_uac1_opts_##name##_store(				\
708					  struct config_item *item,	\
709					  const char *page, size_t len)	\
710{									\
711	struct f_uac1_opts *opts = to_f_uac1_opts(item);		\
712	int ret;							\
713	u32 num;							\
714									\
715	mutex_lock(&opts->lock);					\
716	if (opts->refcnt) {						\
717		ret = -EBUSY;						\
718		goto end;						\
719	}								\
720									\
721	ret = kstrtou32(page, 0, &num);					\
722	if (ret)							\
723		goto end;						\
724									\
725	opts->name = num;						\
726	ret = len;							\
727									\
728end:									\
729	mutex_unlock(&opts->lock);					\
730	return ret;							\
731}									\
732									\
733CONFIGFS_ATTR(f_uac1_opts_, name)
734
735UAC1_ATTRIBUTE(c_chmask);
736UAC1_ATTRIBUTE(c_srate);
737UAC1_ATTRIBUTE(c_ssize);
738UAC1_ATTRIBUTE(p_chmask);
739UAC1_ATTRIBUTE(p_srate);
740UAC1_ATTRIBUTE(p_ssize);
741UAC1_ATTRIBUTE(req_number);
742
743static struct configfs_attribute *f_uac1_attrs[] = {
744	&f_uac1_opts_attr_c_chmask,
745	&f_uac1_opts_attr_c_srate,
746	&f_uac1_opts_attr_c_ssize,
747	&f_uac1_opts_attr_p_chmask,
748	&f_uac1_opts_attr_p_srate,
749	&f_uac1_opts_attr_p_ssize,
750	&f_uac1_opts_attr_req_number,
751	NULL,
752};
753
754static const struct config_item_type f_uac1_func_type = {
755	.ct_item_ops	= &f_uac1_item_ops,
756	.ct_attrs	= f_uac1_attrs,
757	.ct_owner	= THIS_MODULE,
758};
759
760static void f_audio_free_inst(struct usb_function_instance *f)
761{
762	struct f_uac1_opts *opts;
763
764	opts = container_of(f, struct f_uac1_opts, func_inst);
765	kfree(opts);
766}
767
768static struct usb_function_instance *f_audio_alloc_inst(void)
769{
770	struct f_uac1_opts *opts;
771
772	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
773	if (!opts)
774		return ERR_PTR(-ENOMEM);
775
776	mutex_init(&opts->lock);
777	opts->func_inst.free_func_inst = f_audio_free_inst;
778
779	config_group_init_type_name(&opts->func_inst.group, "",
780				    &f_uac1_func_type);
781
782	opts->c_chmask = UAC1_DEF_CCHMASK;
783	opts->c_srate = UAC1_DEF_CSRATE;
784	opts->c_ssize = UAC1_DEF_CSSIZE;
785	opts->p_chmask = UAC1_DEF_PCHMASK;
786	opts->p_srate = UAC1_DEF_PSRATE;
787	opts->p_ssize = UAC1_DEF_PSSIZE;
788	opts->req_number = UAC1_DEF_REQ_NUM;
789	return &opts->func_inst;
790}
791
792static void f_audio_free(struct usb_function *f)
793{
794	struct g_audio *audio;
795	struct f_uac1_opts *opts;
796
797	audio = func_to_g_audio(f);
798	opts = container_of(f->fi, struct f_uac1_opts, func_inst);
799	kfree(audio);
800	mutex_lock(&opts->lock);
801	--opts->refcnt;
802	mutex_unlock(&opts->lock);
803}
804
805static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
806{
807	struct g_audio *audio = func_to_g_audio(f);
808
809	g_audio_cleanup(audio);
810	usb_free_all_descriptors(f);
811
812	audio->gadget = NULL;
813}
814
815static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
816{
817	struct f_uac1 *uac1;
818	struct f_uac1_opts *opts;
819
820	/* allocate and initialize one new instance */
821	uac1 = kzalloc(sizeof(*uac1), GFP_KERNEL);
822	if (!uac1)
823		return ERR_PTR(-ENOMEM);
824
825	opts = container_of(fi, struct f_uac1_opts, func_inst);
826	mutex_lock(&opts->lock);
827	++opts->refcnt;
828	mutex_unlock(&opts->lock);
829
830	uac1->g_audio.func.name = "uac1_func";
831	uac1->g_audio.func.bind = f_audio_bind;
832	uac1->g_audio.func.unbind = f_audio_unbind;
833	uac1->g_audio.func.set_alt = f_audio_set_alt;
834	uac1->g_audio.func.get_alt = f_audio_get_alt;
835	uac1->g_audio.func.setup = f_audio_setup;
836	uac1->g_audio.func.disable = f_audio_disable;
837	uac1->g_audio.func.free_func = f_audio_free;
838
839	return &uac1->g_audio.func;
840}
841
842DECLARE_USB_FUNCTION_INIT(uac1, f_audio_alloc_inst, f_audio_alloc);
843MODULE_LICENSE("GPL");
844MODULE_AUTHOR("Ruslan Bilovol");
845