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  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
 25#define EPIN_EN(_opts) ((_opts)->p_chmask != 0)
 26#define EPOUT_EN(_opts) ((_opts)->c_chmask != 0)
 27
 28struct f_uac1 {
 29	struct g_audio g_audio;
 30	u8 ac_intf, as_in_intf, as_out_intf;
 31	u8 ac_alt, as_in_alt, as_out_alt;	/* needed for get_alt() */
 32};
 33
 34static inline struct f_uac1 *func_to_uac1(struct usb_function *f)
 35{
 36	return container_of(f, struct f_uac1, g_audio.func);
 37}
 38
 39static inline struct f_uac1_opts *g_audio_to_uac1_opts(struct g_audio *audio)
 40{
 41	return container_of(audio->func.fi, struct f_uac1_opts, func_inst);
 42}
 43
 44/*
 45 * DESCRIPTORS ... most are static, but strings and full
 46 * configuration descriptors are built on demand.
 47 */
 48
 49/*
 50 * We have three interfaces - one AudioControl and two AudioStreaming
 51 *
 52 * The driver implements a simple UAC_1 topology.
 53 * USB-OUT -> IT_1 -> OT_2 -> ALSA_Capture
 54 * ALSA_Playback -> IT_3 -> OT_4 -> USB-IN
 55 */
 56
 57/* B.3.1  Standard AC Interface Descriptor */
 58static struct usb_interface_descriptor ac_interface_desc = {
 59	.bLength =		USB_DT_INTERFACE_SIZE,
 60	.bDescriptorType =	USB_DT_INTERFACE,
 61	.bNumEndpoints =	0,
 62	.bInterfaceClass =	USB_CLASS_AUDIO,
 63	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOCONTROL,
 64};
 65
 66/* B.3.2  Class-Specific AC Interface Descriptor */
 67static struct uac1_ac_header_descriptor *ac_header_desc;
 68
 69static struct uac_input_terminal_descriptor usb_out_it_desc = {
 70	.bLength =		UAC_DT_INPUT_TERMINAL_SIZE,
 71	.bDescriptorType =	USB_DT_CS_INTERFACE,
 72	.bDescriptorSubtype =	UAC_INPUT_TERMINAL,
 73	/* .bTerminalID =	DYNAMIC */
 74	.wTerminalType =	cpu_to_le16(UAC_TERMINAL_STREAMING),
 75	.bAssocTerminal =	0,
 76	.wChannelConfig =	cpu_to_le16(0x3),
 77};
 78
 79static struct uac1_output_terminal_descriptor io_out_ot_desc = {
 80	.bLength		= UAC_DT_OUTPUT_TERMINAL_SIZE,
 81	.bDescriptorType	= USB_DT_CS_INTERFACE,
 82	.bDescriptorSubtype	= UAC_OUTPUT_TERMINAL,
 83	/* .bTerminalID =	DYNAMIC */
 84	.wTerminalType		= cpu_to_le16(UAC_OUTPUT_TERMINAL_SPEAKER),
 85	.bAssocTerminal		= 0,
 86	/* .bSourceID =		DYNAMIC */
 87};
 88
 89static struct uac_input_terminal_descriptor io_in_it_desc = {
 90	.bLength		= UAC_DT_INPUT_TERMINAL_SIZE,
 91	.bDescriptorType	= USB_DT_CS_INTERFACE,
 92	.bDescriptorSubtype	= UAC_INPUT_TERMINAL,
 93	/* .bTerminalID		= DYNAMIC */
 94	.wTerminalType		= cpu_to_le16(UAC_INPUT_TERMINAL_MICROPHONE),
 95	.bAssocTerminal		= 0,
 96	.wChannelConfig		= cpu_to_le16(0x3),
 97};
 98
 99static struct uac1_output_terminal_descriptor usb_in_ot_desc = {
100	.bLength =		UAC_DT_OUTPUT_TERMINAL_SIZE,
101	.bDescriptorType =	USB_DT_CS_INTERFACE,
102	.bDescriptorSubtype =	UAC_OUTPUT_TERMINAL,
103	/* .bTerminalID =	DYNAMIC */
104	.wTerminalType =	cpu_to_le16(UAC_TERMINAL_STREAMING),
105	.bAssocTerminal =	0,
106	/* .bSourceID =		DYNAMIC */
107};
108
109/* B.4.1  Standard AS Interface Descriptor */
110static struct usb_interface_descriptor as_out_interface_alt_0_desc = {
111	.bLength =		USB_DT_INTERFACE_SIZE,
112	.bDescriptorType =	USB_DT_INTERFACE,
113	.bAlternateSetting =	0,
114	.bNumEndpoints =	0,
115	.bInterfaceClass =	USB_CLASS_AUDIO,
116	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
117};
118
119static struct usb_interface_descriptor as_out_interface_alt_1_desc = {
120	.bLength =		USB_DT_INTERFACE_SIZE,
121	.bDescriptorType =	USB_DT_INTERFACE,
122	.bAlternateSetting =	1,
123	.bNumEndpoints =	1,
124	.bInterfaceClass =	USB_CLASS_AUDIO,
125	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
126};
127
128static struct usb_interface_descriptor as_in_interface_alt_0_desc = {
129	.bLength =		USB_DT_INTERFACE_SIZE,
130	.bDescriptorType =	USB_DT_INTERFACE,
131	.bAlternateSetting =	0,
132	.bNumEndpoints =	0,
133	.bInterfaceClass =	USB_CLASS_AUDIO,
134	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
135};
136
137static struct usb_interface_descriptor as_in_interface_alt_1_desc = {
138	.bLength =		USB_DT_INTERFACE_SIZE,
139	.bDescriptorType =	USB_DT_INTERFACE,
140	.bAlternateSetting =	1,
141	.bNumEndpoints =	1,
142	.bInterfaceClass =	USB_CLASS_AUDIO,
143	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOSTREAMING,
144};
145
146/* B.4.2  Class-Specific AS Interface Descriptor */
147static struct uac1_as_header_descriptor as_out_header_desc = {
148	.bLength =		UAC_DT_AS_HEADER_SIZE,
149	.bDescriptorType =	USB_DT_CS_INTERFACE,
150	.bDescriptorSubtype =	UAC_AS_GENERAL,
151	/* .bTerminalLink =	DYNAMIC */
152	.bDelay =		1,
153	.wFormatTag =		cpu_to_le16(UAC_FORMAT_TYPE_I_PCM),
154};
155
156static struct uac1_as_header_descriptor as_in_header_desc = {
157	.bLength =		UAC_DT_AS_HEADER_SIZE,
158	.bDescriptorType =	USB_DT_CS_INTERFACE,
159	.bDescriptorSubtype =	UAC_AS_GENERAL,
160	/* .bTerminalLink =	DYNAMIC */
161	.bDelay =		1,
162	.wFormatTag =		cpu_to_le16(UAC_FORMAT_TYPE_I_PCM),
163};
164
165DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
166
167static struct uac_format_type_i_discrete_descriptor_1 as_out_type_i_desc = {
168	.bLength =		UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
169	.bDescriptorType =	USB_DT_CS_INTERFACE,
170	.bDescriptorSubtype =	UAC_FORMAT_TYPE,
171	.bFormatType =		UAC_FORMAT_TYPE_I,
172	.bSubframeSize =	2,
173	.bBitResolution =	16,
174	.bSamFreqType =		1,
175};
176
177/* Standard ISO OUT Endpoint Descriptor */
178static struct usb_endpoint_descriptor as_out_ep_desc  = {
179	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
180	.bDescriptorType =	USB_DT_ENDPOINT,
181	.bEndpointAddress =	USB_DIR_OUT,
182	.bmAttributes =		USB_ENDPOINT_SYNC_ADAPTIVE
183				| USB_ENDPOINT_XFER_ISOC,
184	.wMaxPacketSize	=	cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
185	.bInterval =		4,
186};
187
188/* Class-specific AS ISO OUT Endpoint Descriptor */
189static struct uac_iso_endpoint_descriptor as_iso_out_desc = {
190	.bLength =		UAC_ISO_ENDPOINT_DESC_SIZE,
191	.bDescriptorType =	USB_DT_CS_ENDPOINT,
192	.bDescriptorSubtype =	UAC_EP_GENERAL,
193	.bmAttributes =		1,
194	.bLockDelayUnits =	1,
195	.wLockDelay =		cpu_to_le16(1),
196};
197
198static struct uac_format_type_i_discrete_descriptor_1 as_in_type_i_desc = {
199	.bLength =		UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
200	.bDescriptorType =	USB_DT_CS_INTERFACE,
201	.bDescriptorSubtype =	UAC_FORMAT_TYPE,
202	.bFormatType =		UAC_FORMAT_TYPE_I,
203	.bSubframeSize =	2,
204	.bBitResolution =	16,
205	.bSamFreqType =		1,
206};
207
208/* Standard ISO OUT Endpoint Descriptor */
209static struct usb_endpoint_descriptor as_in_ep_desc  = {
210	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
211	.bDescriptorType =	USB_DT_ENDPOINT,
212	.bEndpointAddress =	USB_DIR_IN,
213	.bmAttributes =		USB_ENDPOINT_SYNC_ASYNC
214				| USB_ENDPOINT_XFER_ISOC,
215	.wMaxPacketSize	=	cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
216	.bInterval =		4,
217};
218
219/* Class-specific AS ISO OUT Endpoint Descriptor */
220static struct uac_iso_endpoint_descriptor as_iso_in_desc = {
221	.bLength =		UAC_ISO_ENDPOINT_DESC_SIZE,
222	.bDescriptorType =	USB_DT_CS_ENDPOINT,
223	.bDescriptorSubtype =	UAC_EP_GENERAL,
224	.bmAttributes =		1,
225	.bLockDelayUnits =	0,
226	.wLockDelay =		0,
227};
228
229static struct usb_descriptor_header *f_audio_desc[] = {
230	(struct usb_descriptor_header *)&ac_interface_desc,
231	(struct usb_descriptor_header *)&ac_header_desc,
232
233	(struct usb_descriptor_header *)&usb_out_it_desc,
234	(struct usb_descriptor_header *)&io_out_ot_desc,
235	(struct usb_descriptor_header *)&io_in_it_desc,
236	(struct usb_descriptor_header *)&usb_in_ot_desc,
237
238	(struct usb_descriptor_header *)&as_out_interface_alt_0_desc,
239	(struct usb_descriptor_header *)&as_out_interface_alt_1_desc,
240	(struct usb_descriptor_header *)&as_out_header_desc,
241
242	(struct usb_descriptor_header *)&as_out_type_i_desc,
243
244	(struct usb_descriptor_header *)&as_out_ep_desc,
245	(struct usb_descriptor_header *)&as_iso_out_desc,
246
247	(struct usb_descriptor_header *)&as_in_interface_alt_0_desc,
248	(struct usb_descriptor_header *)&as_in_interface_alt_1_desc,
249	(struct usb_descriptor_header *)&as_in_header_desc,
250
251	(struct usb_descriptor_header *)&as_in_type_i_desc,
252
253	(struct usb_descriptor_header *)&as_in_ep_desc,
254	(struct usb_descriptor_header *)&as_iso_in_desc,
255	NULL,
256};
257
258enum {
259	STR_AC_IF,
260	STR_USB_OUT_IT,
261	STR_USB_OUT_IT_CH_NAMES,
262	STR_IO_OUT_OT,
263	STR_IO_IN_IT,
264	STR_IO_IN_IT_CH_NAMES,
265	STR_USB_IN_OT,
266	STR_AS_OUT_IF_ALT0,
267	STR_AS_OUT_IF_ALT1,
268	STR_AS_IN_IF_ALT0,
269	STR_AS_IN_IF_ALT1,
270};
271
272static struct usb_string strings_uac1[] = {
273	[STR_AC_IF].s = "AC Interface",
274	[STR_USB_OUT_IT].s = "Playback Input terminal",
275	[STR_USB_OUT_IT_CH_NAMES].s = "Playback Channels",
276	[STR_IO_OUT_OT].s = "Playback Output terminal",
277	[STR_IO_IN_IT].s = "Capture Input terminal",
278	[STR_IO_IN_IT_CH_NAMES].s = "Capture Channels",
279	[STR_USB_IN_OT].s = "Capture Output terminal",
280	[STR_AS_OUT_IF_ALT0].s = "Playback Inactive",
281	[STR_AS_OUT_IF_ALT1].s = "Playback Active",
282	[STR_AS_IN_IF_ALT0].s = "Capture Inactive",
283	[STR_AS_IN_IF_ALT1].s = "Capture Active",
284	{ },
285};
286
287static struct usb_gadget_strings str_uac1 = {
288	.language = 0x0409,	/* en-us */
289	.strings = strings_uac1,
290};
291
292static struct usb_gadget_strings *uac1_strings[] = {
293	&str_uac1,
294	NULL,
295};
296
297/*
298 * This function is an ALSA sound card following USB Audio Class Spec 1.0.
299 */
300
301static int audio_set_endpoint_req(struct usb_function *f,
302		const struct usb_ctrlrequest *ctrl)
303{
304	struct usb_composite_dev *cdev = f->config->cdev;
305	int			value = -EOPNOTSUPP;
306	u16			ep = le16_to_cpu(ctrl->wIndex);
307	u16			len = le16_to_cpu(ctrl->wLength);
308	u16			w_value = le16_to_cpu(ctrl->wValue);
309
310	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
311			ctrl->bRequest, w_value, len, ep);
312
313	switch (ctrl->bRequest) {
314	case UAC_SET_CUR:
315		value = len;
316		break;
317
318	case UAC_SET_MIN:
319		break;
320
321	case UAC_SET_MAX:
322		break;
323
324	case UAC_SET_RES:
325		break;
326
327	case UAC_SET_MEM:
328		break;
329
330	default:
331		break;
332	}
333
334	return value;
335}
336
337static int audio_get_endpoint_req(struct usb_function *f,
338		const struct usb_ctrlrequest *ctrl)
339{
340	struct usb_composite_dev *cdev = f->config->cdev;
341	int value = -EOPNOTSUPP;
342	u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
343	u16 len = le16_to_cpu(ctrl->wLength);
344	u16 w_value = le16_to_cpu(ctrl->wValue);
345
346	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
347			ctrl->bRequest, w_value, len, ep);
348
349	switch (ctrl->bRequest) {
350	case UAC_GET_CUR:
351	case UAC_GET_MIN:
352	case UAC_GET_MAX:
353	case UAC_GET_RES:
354		value = len;
355		break;
356	case UAC_GET_MEM:
357		break;
358	default:
359		break;
360	}
361
362	return value;
363}
364
365static int
366f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
367{
368	struct usb_composite_dev *cdev = f->config->cdev;
369	struct usb_request	*req = cdev->req;
370	int			value = -EOPNOTSUPP;
371	u16			w_index = le16_to_cpu(ctrl->wIndex);
372	u16			w_value = le16_to_cpu(ctrl->wValue);
373	u16			w_length = le16_to_cpu(ctrl->wLength);
374
375	/* composite driver infrastructure handles everything; interface
376	 * activation uses set_alt().
377	 */
378	switch (ctrl->bRequestType) {
379	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
380		value = audio_set_endpoint_req(f, ctrl);
381		break;
382
383	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
384		value = audio_get_endpoint_req(f, ctrl);
385		break;
386
387	default:
388		ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
389			ctrl->bRequestType, ctrl->bRequest,
390			w_value, w_index, w_length);
391	}
392
393	/* respond with data transfer or status phase? */
394	if (value >= 0) {
395		DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
396			ctrl->bRequestType, ctrl->bRequest,
397			w_value, w_index, w_length);
398		req->zero = 0;
399		req->length = value;
400		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
401		if (value < 0)
402			ERROR(cdev, "audio response on err %d\n", value);
403	}
404
405	/* device either stalls (value < 0) or reports success */
406	return value;
407}
408
409static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
410{
411	struct usb_composite_dev *cdev = f->config->cdev;
412	struct usb_gadget *gadget = cdev->gadget;
413	struct device *dev = &gadget->dev;
414	struct f_uac1 *uac1 = func_to_uac1(f);
415	int ret = 0;
416
417	/* No i/f has more than 2 alt settings */
418	if (alt > 1) {
419		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
420		return -EINVAL;
421	}
422
423	if (intf == uac1->ac_intf) {
424		/* Control I/f has only 1 AltSetting - 0 */
425		if (alt) {
426			dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
427			return -EINVAL;
428		}
429		return 0;
430	}
431
432	if (intf == uac1->as_out_intf) {
433		uac1->as_out_alt = alt;
434
435		if (alt)
436			ret = u_audio_start_capture(&uac1->g_audio);
437		else
438			u_audio_stop_capture(&uac1->g_audio);
439	} else if (intf == uac1->as_in_intf) {
440		uac1->as_in_alt = alt;
441
442		if (alt)
443			ret = u_audio_start_playback(&uac1->g_audio);
444		else
445			u_audio_stop_playback(&uac1->g_audio);
446	} else {
447		dev_err(dev, "%s:%d Error!\n", __func__, __LINE__);
448		return -EINVAL;
449	}
450
451	return ret;
452}
453
454static int f_audio_get_alt(struct usb_function *f, unsigned intf)
455{
456	struct usb_composite_dev *cdev = f->config->cdev;
457	struct usb_gadget *gadget = cdev->gadget;
458	struct device *dev = &gadget->dev;
459	struct f_uac1 *uac1 = func_to_uac1(f);
460
461	if (intf == uac1->ac_intf)
462		return uac1->ac_alt;
463	else if (intf == uac1->as_out_intf)
464		return uac1->as_out_alt;
465	else if (intf == uac1->as_in_intf)
466		return uac1->as_in_alt;
467	else
468		dev_err(dev, "%s:%d Invalid Interface %d!\n",
469			__func__, __LINE__, intf);
470
471	return -EINVAL;
472}
473
474
475static void f_audio_disable(struct usb_function *f)
476{
477	struct f_uac1 *uac1 = func_to_uac1(f);
478
479	uac1->as_out_alt = 0;
480	uac1->as_in_alt = 0;
481
482	u_audio_stop_playback(&uac1->g_audio);
483	u_audio_stop_capture(&uac1->g_audio);
484}
485
486/*-------------------------------------------------------------------------*/
487
488static struct
489uac1_ac_header_descriptor *build_ac_header_desc(struct f_uac1_opts *opts)
490{
491	struct uac1_ac_header_descriptor *ac_desc;
492	int ac_header_desc_size;
493	int num_ifaces = 0;
494
495	if (EPOUT_EN(opts))
496		num_ifaces++;
497	if (EPIN_EN(opts))
498		num_ifaces++;
499
500	ac_header_desc_size = UAC_DT_AC_HEADER_SIZE(num_ifaces);
501
502	ac_desc = kzalloc(ac_header_desc_size, GFP_KERNEL);
503	if (!ac_desc)
504		return NULL;
505
506	ac_desc->bLength = ac_header_desc_size;
507	ac_desc->bDescriptorType = USB_DT_CS_INTERFACE;
508	ac_desc->bDescriptorSubtype = UAC_HEADER;
509	ac_desc->bcdADC = cpu_to_le16(0x0100);
510	ac_desc->bInCollection = num_ifaces;
511
512	/* wTotalLength and baInterfaceNr will be defined later */
513
514	return ac_desc;
515}
516
517/* Use macro to overcome line length limitation */
518#define USBDHDR(p) (struct usb_descriptor_header *)(p)
519
520static void setup_descriptor(struct f_uac1_opts *opts)
521{
522	/* patch descriptors */
523	int i = 1; /* ID's start with 1 */
524
525	if (EPOUT_EN(opts))
526		usb_out_it_desc.bTerminalID = i++;
527	if (EPIN_EN(opts))
528		io_in_it_desc.bTerminalID = i++;
529	if (EPOUT_EN(opts))
530		io_out_ot_desc.bTerminalID = i++;
531	if (EPIN_EN(opts))
532		usb_in_ot_desc.bTerminalID = i++;
533
534	usb_in_ot_desc.bSourceID = io_in_it_desc.bTerminalID;
535	io_out_ot_desc.bSourceID = usb_out_it_desc.bTerminalID;
536
537	as_out_header_desc.bTerminalLink = usb_out_it_desc.bTerminalID;
538	as_in_header_desc.bTerminalLink = usb_in_ot_desc.bTerminalID;
539
540	ac_header_desc->wTotalLength = cpu_to_le16(ac_header_desc->bLength);
541
542	if (EPIN_EN(opts)) {
543		u16 len = le16_to_cpu(ac_header_desc->wTotalLength);
544
545		len += sizeof(usb_in_ot_desc);
546		len += sizeof(io_in_it_desc);
547		ac_header_desc->wTotalLength = cpu_to_le16(len);
548	}
549	if (EPOUT_EN(opts)) {
550		u16 len = le16_to_cpu(ac_header_desc->wTotalLength);
551
552		len += sizeof(usb_out_it_desc);
553		len += sizeof(io_out_ot_desc);
554		ac_header_desc->wTotalLength = cpu_to_le16(len);
555	}
556
557	i = 0;
558	f_audio_desc[i++] = USBDHDR(&ac_interface_desc);
559	f_audio_desc[i++] = USBDHDR(ac_header_desc);
560
561	if (EPOUT_EN(opts)) {
562		f_audio_desc[i++] = USBDHDR(&usb_out_it_desc);
563		f_audio_desc[i++] = USBDHDR(&io_out_ot_desc);
564	}
565
566	if (EPIN_EN(opts)) {
567		f_audio_desc[i++] = USBDHDR(&io_in_it_desc);
568		f_audio_desc[i++] = USBDHDR(&usb_in_ot_desc);
569	}
570
571	if (EPOUT_EN(opts)) {
572		f_audio_desc[i++] = USBDHDR(&as_out_interface_alt_0_desc);
573		f_audio_desc[i++] = USBDHDR(&as_out_interface_alt_1_desc);
574		f_audio_desc[i++] = USBDHDR(&as_out_header_desc);
575		f_audio_desc[i++] = USBDHDR(&as_out_type_i_desc);
576		f_audio_desc[i++] = USBDHDR(&as_out_ep_desc);
577		f_audio_desc[i++] = USBDHDR(&as_iso_out_desc);
578	}
579	if (EPIN_EN(opts)) {
580		f_audio_desc[i++] = USBDHDR(&as_in_interface_alt_0_desc);
581		f_audio_desc[i++] = USBDHDR(&as_in_interface_alt_1_desc);
582		f_audio_desc[i++] = USBDHDR(&as_in_header_desc);
583		f_audio_desc[i++] = USBDHDR(&as_in_type_i_desc);
584		f_audio_desc[i++] = USBDHDR(&as_in_ep_desc);
585		f_audio_desc[i++] = USBDHDR(&as_iso_in_desc);
586	}
587	f_audio_desc[i] = NULL;
588}
589
590static int f_audio_validate_opts(struct g_audio *audio, struct device *dev)
591{
592	struct f_uac1_opts *opts = g_audio_to_uac1_opts(audio);
593
594	if (!opts->p_chmask && !opts->c_chmask) {
595		dev_err(dev, "Error: no playback and capture channels\n");
596		return -EINVAL;
597	} else if (opts->p_chmask & ~UAC1_CHANNEL_MASK) {
598		dev_err(dev, "Error: unsupported playback channels mask\n");
599		return -EINVAL;
600	} else if (opts->c_chmask & ~UAC1_CHANNEL_MASK) {
601		dev_err(dev, "Error: unsupported capture channels mask\n");
602		return -EINVAL;
603	} else if ((opts->p_ssize < 1) || (opts->p_ssize > 4)) {
604		dev_err(dev, "Error: incorrect playback sample size\n");
605		return -EINVAL;
606	} else if ((opts->c_ssize < 1) || (opts->c_ssize > 4)) {
607		dev_err(dev, "Error: incorrect capture sample size\n");
608		return -EINVAL;
609	} else if (!opts->p_srate) {
610		dev_err(dev, "Error: incorrect playback sampling rate\n");
611		return -EINVAL;
612	} else if (!opts->c_srate) {
613		dev_err(dev, "Error: incorrect capture sampling rate\n");
614		return -EINVAL;
615	}
616
617	return 0;
618}
619
620/* audio function driver setup/binding */
621static int f_audio_bind(struct usb_configuration *c, struct usb_function *f)
622{
623	struct usb_composite_dev	*cdev = c->cdev;
624	struct usb_gadget		*gadget = cdev->gadget;
625	struct device			*dev = &gadget->dev;
626	struct f_uac1			*uac1 = func_to_uac1(f);
627	struct g_audio			*audio = func_to_g_audio(f);
628	struct f_uac1_opts		*audio_opts;
629	struct usb_ep			*ep = NULL;
630	struct usb_string		*us;
631	u8				*sam_freq;
632	int				rate;
633	int				ba_iface_id;
634	int				status;
635
636	status = f_audio_validate_opts(audio, dev);
637	if (status)
638		return status;
639
640	audio_opts = container_of(f->fi, struct f_uac1_opts, func_inst);
641
642	us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
643	if (IS_ERR(us))
644		return PTR_ERR(us);
645
646	ac_header_desc = build_ac_header_desc(audio_opts);
647	if (!ac_header_desc)
648		return -ENOMEM;
649
650	ac_interface_desc.iInterface = us[STR_AC_IF].id;
651	usb_out_it_desc.iTerminal = us[STR_USB_OUT_IT].id;
652	usb_out_it_desc.iChannelNames = us[STR_USB_OUT_IT_CH_NAMES].id;
653	io_out_ot_desc.iTerminal = us[STR_IO_OUT_OT].id;
654	as_out_interface_alt_0_desc.iInterface = us[STR_AS_OUT_IF_ALT0].id;
655	as_out_interface_alt_1_desc.iInterface = us[STR_AS_OUT_IF_ALT1].id;
656	io_in_it_desc.iTerminal = us[STR_IO_IN_IT].id;
657	io_in_it_desc.iChannelNames = us[STR_IO_IN_IT_CH_NAMES].id;
658	usb_in_ot_desc.iTerminal = us[STR_USB_IN_OT].id;
659	as_in_interface_alt_0_desc.iInterface = us[STR_AS_IN_IF_ALT0].id;
660	as_in_interface_alt_1_desc.iInterface = us[STR_AS_IN_IF_ALT1].id;
661
662	/* Set channel numbers */
663	usb_out_it_desc.bNrChannels = num_channels(audio_opts->c_chmask);
664	usb_out_it_desc.wChannelConfig = cpu_to_le16(audio_opts->c_chmask);
665	as_out_type_i_desc.bNrChannels = num_channels(audio_opts->c_chmask);
666	as_out_type_i_desc.bSubframeSize = audio_opts->c_ssize;
667	as_out_type_i_desc.bBitResolution = audio_opts->c_ssize * 8;
668	io_in_it_desc.bNrChannels = num_channels(audio_opts->p_chmask);
669	io_in_it_desc.wChannelConfig = cpu_to_le16(audio_opts->p_chmask);
670	as_in_type_i_desc.bNrChannels = num_channels(audio_opts->p_chmask);
671	as_in_type_i_desc.bSubframeSize = audio_opts->p_ssize;
672	as_in_type_i_desc.bBitResolution = audio_opts->p_ssize * 8;
673
674	/* Set sample rates */
675	rate = audio_opts->c_srate;
676	sam_freq = as_out_type_i_desc.tSamFreq[0];
677	memcpy(sam_freq, &rate, 3);
678	rate = audio_opts->p_srate;
679	sam_freq = as_in_type_i_desc.tSamFreq[0];
680	memcpy(sam_freq, &rate, 3);
681
682	/* allocate instance-specific interface IDs, and patch descriptors */
683	status = usb_interface_id(c, f);
684	if (status < 0)
685		goto fail;
686	ac_interface_desc.bInterfaceNumber = status;
687	uac1->ac_intf = status;
688	uac1->ac_alt = 0;
689
690	ba_iface_id = 0;
691
692	if (EPOUT_EN(audio_opts)) {
693		status = usb_interface_id(c, f);
694		if (status < 0)
695			goto fail;
696		as_out_interface_alt_0_desc.bInterfaceNumber = status;
697		as_out_interface_alt_1_desc.bInterfaceNumber = status;
698		ac_header_desc->baInterfaceNr[ba_iface_id++] = status;
699		uac1->as_out_intf = status;
700		uac1->as_out_alt = 0;
701	}
702
703	if (EPIN_EN(audio_opts)) {
704		status = usb_interface_id(c, f);
705		if (status < 0)
706			goto fail;
707		as_in_interface_alt_0_desc.bInterfaceNumber = status;
708		as_in_interface_alt_1_desc.bInterfaceNumber = status;
709		ac_header_desc->baInterfaceNr[ba_iface_id++] = status;
710		uac1->as_in_intf = status;
711		uac1->as_in_alt = 0;
712	}
713
714	audio->gadget = gadget;
715
716	status = -ENODEV;
717
718	/* allocate instance-specific endpoints */
719	if (EPOUT_EN(audio_opts)) {
720		ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
721		if (!ep)
722			goto fail;
723		audio->out_ep = ep;
724		audio->out_ep->desc = &as_out_ep_desc;
725	}
726
727	if (EPIN_EN(audio_opts)) {
728		ep = usb_ep_autoconfig(cdev->gadget, &as_in_ep_desc);
729		if (!ep)
730			goto fail;
731		audio->in_ep = ep;
732		audio->in_ep->desc = &as_in_ep_desc;
733	}
734
735	setup_descriptor(audio_opts);
736
737	/* copy descriptors, and track endpoint copies */
738	status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL,
739					NULL);
740	if (status)
741		goto fail;
742
743	audio->out_ep_maxpsize = le16_to_cpu(as_out_ep_desc.wMaxPacketSize);
744	audio->in_ep_maxpsize = le16_to_cpu(as_in_ep_desc.wMaxPacketSize);
745	audio->params.c_chmask = audio_opts->c_chmask;
746	audio->params.c_srate = audio_opts->c_srate;
747	audio->params.c_ssize = audio_opts->c_ssize;
748	audio->params.p_chmask = audio_opts->p_chmask;
749	audio->params.p_srate = audio_opts->p_srate;
750	audio->params.p_ssize = audio_opts->p_ssize;
751	audio->params.req_number = audio_opts->req_number;
752
753	status = g_audio_setup(audio, "UAC1_PCM", "UAC1_Gadget");
754	if (status)
755		goto err_card_register;
756
757	return 0;
758
759err_card_register:
760	usb_free_all_descriptors(f);
761fail:
762	kfree(ac_header_desc);
763	ac_header_desc = NULL;
764	return status;
765}
766
767/*-------------------------------------------------------------------------*/
768
769static inline struct f_uac1_opts *to_f_uac1_opts(struct config_item *item)
770{
771	return container_of(to_config_group(item), struct f_uac1_opts,
772			    func_inst.group);
773}
774
775static void f_uac1_attr_release(struct config_item *item)
776{
777	struct f_uac1_opts *opts = to_f_uac1_opts(item);
778
779	usb_put_function_instance(&opts->func_inst);
780}
781
782static struct configfs_item_operations f_uac1_item_ops = {
783	.release	= f_uac1_attr_release,
784};
785
786#define UAC1_ATTRIBUTE(name)						\
787static ssize_t f_uac1_opts_##name##_show(				\
788					  struct config_item *item,	\
789					  char *page)			\
790{									\
791	struct f_uac1_opts *opts = to_f_uac1_opts(item);		\
792	int result;							\
793									\
794	mutex_lock(&opts->lock);					\
795	result = sprintf(page, "%u\n", opts->name);			\
796	mutex_unlock(&opts->lock);					\
797									\
798	return result;							\
799}									\
800									\
801static ssize_t f_uac1_opts_##name##_store(				\
802					  struct config_item *item,	\
803					  const char *page, size_t len)	\
804{									\
805	struct f_uac1_opts *opts = to_f_uac1_opts(item);		\
806	int ret;							\
807	u32 num;							\
808									\
809	mutex_lock(&opts->lock);					\
810	if (opts->refcnt) {						\
811		ret = -EBUSY;						\
812		goto end;						\
813	}								\
814									\
815	ret = kstrtou32(page, 0, &num);					\
816	if (ret)							\
817		goto end;						\
818									\
819	opts->name = num;						\
820	ret = len;							\
821									\
822end:									\
823	mutex_unlock(&opts->lock);					\
824	return ret;							\
825}									\
826									\
827CONFIGFS_ATTR(f_uac1_opts_, name)
828
829UAC1_ATTRIBUTE(c_chmask);
830UAC1_ATTRIBUTE(c_srate);
831UAC1_ATTRIBUTE(c_ssize);
832UAC1_ATTRIBUTE(p_chmask);
833UAC1_ATTRIBUTE(p_srate);
834UAC1_ATTRIBUTE(p_ssize);
835UAC1_ATTRIBUTE(req_number);
836
837static struct configfs_attribute *f_uac1_attrs[] = {
838	&f_uac1_opts_attr_c_chmask,
839	&f_uac1_opts_attr_c_srate,
840	&f_uac1_opts_attr_c_ssize,
841	&f_uac1_opts_attr_p_chmask,
842	&f_uac1_opts_attr_p_srate,
843	&f_uac1_opts_attr_p_ssize,
844	&f_uac1_opts_attr_req_number,
845	NULL,
846};
847
848static const struct config_item_type f_uac1_func_type = {
849	.ct_item_ops	= &f_uac1_item_ops,
850	.ct_attrs	= f_uac1_attrs,
851	.ct_owner	= THIS_MODULE,
852};
853
854static void f_audio_free_inst(struct usb_function_instance *f)
855{
856	struct f_uac1_opts *opts;
857
858	opts = container_of(f, struct f_uac1_opts, func_inst);
859	kfree(opts);
860}
861
862static struct usb_function_instance *f_audio_alloc_inst(void)
863{
864	struct f_uac1_opts *opts;
865
866	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
867	if (!opts)
868		return ERR_PTR(-ENOMEM);
869
870	mutex_init(&opts->lock);
871	opts->func_inst.free_func_inst = f_audio_free_inst;
872
873	config_group_init_type_name(&opts->func_inst.group, "",
874				    &f_uac1_func_type);
875
876	opts->c_chmask = UAC1_DEF_CCHMASK;
877	opts->c_srate = UAC1_DEF_CSRATE;
878	opts->c_ssize = UAC1_DEF_CSSIZE;
879	opts->p_chmask = UAC1_DEF_PCHMASK;
880	opts->p_srate = UAC1_DEF_PSRATE;
881	opts->p_ssize = UAC1_DEF_PSSIZE;
882	opts->req_number = UAC1_DEF_REQ_NUM;
883	return &opts->func_inst;
884}
885
886static void f_audio_free(struct usb_function *f)
887{
888	struct g_audio *audio;
889	struct f_uac1_opts *opts;
890
891	audio = func_to_g_audio(f);
892	opts = container_of(f->fi, struct f_uac1_opts, func_inst);
893	kfree(audio);
894	mutex_lock(&opts->lock);
895	--opts->refcnt;
896	mutex_unlock(&opts->lock);
897}
898
899static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
900{
901	struct g_audio *audio = func_to_g_audio(f);
902
903	g_audio_cleanup(audio);
904	usb_free_all_descriptors(f);
905
906	kfree(ac_header_desc);
907	ac_header_desc = NULL;
908
909	audio->gadget = NULL;
910}
911
912static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
913{
914	struct f_uac1 *uac1;
915	struct f_uac1_opts *opts;
916
917	/* allocate and initialize one new instance */
918	uac1 = kzalloc(sizeof(*uac1), GFP_KERNEL);
919	if (!uac1)
920		return ERR_PTR(-ENOMEM);
921
922	opts = container_of(fi, struct f_uac1_opts, func_inst);
923	mutex_lock(&opts->lock);
924	++opts->refcnt;
925	mutex_unlock(&opts->lock);
926
927	uac1->g_audio.func.name = "uac1_func";
928	uac1->g_audio.func.bind = f_audio_bind;
929	uac1->g_audio.func.unbind = f_audio_unbind;
930	uac1->g_audio.func.set_alt = f_audio_set_alt;
931	uac1->g_audio.func.get_alt = f_audio_get_alt;
932	uac1->g_audio.func.setup = f_audio_setup;
933	uac1->g_audio.func.disable = f_audio_disable;
934	uac1->g_audio.func.free_func = f_audio_free;
935
936	return &uac1->g_audio.func;
937}
938
939DECLARE_USB_FUNCTION_INIT(uac1, f_audio_alloc_inst, f_audio_alloc);
940MODULE_LICENSE("GPL");
941MODULE_AUTHOR("Ruslan Bilovol");