1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * f_audio.c -- USB Audio class function driver
   4  *
   5 * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
   6 * Copyright (C) 2008 Analog Devices, Inc
   7 */
   8
   9#include <linux/slab.h>
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/device.h>
  13#include <linux/atomic.h>
  14
  15#include "u_uac1_legacy.h"
  16
  17static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value);
  18static int generic_get_cmd(struct usb_audio_control *con, u8 cmd);
  19
  20/*
  21 * DESCRIPTORS ... most are static, but strings and full
  22 * configuration descriptors are built on demand.
  23 */
  24
  25/*
  26 * We have two interfaces- AudioControl and AudioStreaming
  27 * TODO: only supcard playback currently
  28 */
  29#define F_AUDIO_AC_INTERFACE	0
  30#define F_AUDIO_AS_INTERFACE	1
  31#define F_AUDIO_NUM_INTERFACES	1
  32
  33/* B.3.1  Standard AC Interface Descriptor */
  34static struct usb_interface_descriptor ac_interface_desc = {
  35	.bLength =		USB_DT_INTERFACE_SIZE,
  36	.bDescriptorType =	USB_DT_INTERFACE,
  37	.bNumEndpoints =	0,
  38	.bInterfaceClass =	USB_CLASS_AUDIO,
  39	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOCONTROL,
  40};
  41
  42/*
  43 * The number of AudioStreaming and MIDIStreaming interfaces
  44 * in the Audio Interface Collection
  45 */
  46DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
  47
  48#define UAC_DT_AC_HEADER_LENGTH	UAC_DT_AC_HEADER_SIZE(F_AUDIO_NUM_INTERFACES)
  49/* 1 input terminal, 1 output terminal and 1 feature unit */
  50#define UAC_DT_TOTAL_LENGTH (UAC_DT_AC_HEADER_LENGTH + UAC_DT_INPUT_TERMINAL_SIZE \
  51	+ UAC_DT_OUTPUT_TERMINAL_SIZE + UAC_DT_FEATURE_UNIT_SIZE(0))
  52/* B.3.2  Class-Specific AC Interface Descriptor */
  53static struct uac1_ac_header_descriptor_1 ac_header_desc = {
  54	.bLength =		UAC_DT_AC_HEADER_LENGTH,
  55	.bDescriptorType =	USB_DT_CS_INTERFACE,
  56	.bDescriptorSubtype =	UAC_HEADER,
  57	.bcdADC =		cpu_to_le16(0x0100),
  58	.wTotalLength =		cpu_to_le16(UAC_DT_TOTAL_LENGTH),
  59	.bInCollection =	F_AUDIO_NUM_INTERFACES,
  60	.baInterfaceNr = {
  61	/* Interface number of the first AudioStream interface */
  62		[0] =		1,
  63	}
  64};
  65
  66#define INPUT_TERMINAL_ID	1
  67static struct uac_input_terminal_descriptor input_terminal_desc = {
  68	.bLength =		UAC_DT_INPUT_TERMINAL_SIZE,
  69	.bDescriptorType =	USB_DT_CS_INTERFACE,
  70	.bDescriptorSubtype =	UAC_INPUT_TERMINAL,
  71	.bTerminalID =		INPUT_TERMINAL_ID,
  72	.wTerminalType =	UAC_TERMINAL_STREAMING,
  73	.bAssocTerminal =	0,
  74	.wChannelConfig =	0x3,
  75};
  76
  77DECLARE_UAC_FEATURE_UNIT_DESCRIPTOR(0);
  78
  79#define FEATURE_UNIT_ID		2
  80static struct uac_feature_unit_descriptor_0 feature_unit_desc = {
  81	.bLength		= UAC_DT_FEATURE_UNIT_SIZE(0),
  82	.bDescriptorType	= USB_DT_CS_INTERFACE,
  83	.bDescriptorSubtype	= UAC_FEATURE_UNIT,
  84	.bUnitID		= FEATURE_UNIT_ID,
  85	.bSourceID		= INPUT_TERMINAL_ID,
  86	.bControlSize		= 2,
  87	.bmaControls[0]		= (UAC_FU_MUTE | UAC_FU_VOLUME),
  88};
  89
  90static struct usb_audio_control mute_control = {
  91	.list = LIST_HEAD_INIT(mute_control.list),
  92	.name = "Mute Control",
  93	.type = UAC_FU_MUTE,
  94	/* Todo: add real Mute control code */
  95	.set = generic_set_cmd,
  96	.get = generic_get_cmd,
  97};
  98
  99static struct usb_audio_control volume_control = {
 100	.list = LIST_HEAD_INIT(volume_control.list),
 101	.name = "Volume Control",
 102	.type = UAC_FU_VOLUME,
 103	/* Todo: add real Volume control code */
 104	.set = generic_set_cmd,
 105	.get = generic_get_cmd,
 106};
 107
 108static struct usb_audio_control_selector feature_unit = {
 109	.list = LIST_HEAD_INIT(feature_unit.list),
 110	.id = FEATURE_UNIT_ID,
 111	.name = "Mute & Volume Control",
 112	.type = UAC_FEATURE_UNIT,
 113	.desc = (struct usb_descriptor_header *)&feature_unit_desc,
 114};
 115
 116#define OUTPUT_TERMINAL_ID	3
 117static struct uac1_output_terminal_descriptor output_terminal_desc = {
 118	.bLength		= UAC_DT_OUTPUT_TERMINAL_SIZE,
 119	.bDescriptorType	= USB_DT_CS_INTERFACE,
 120	.bDescriptorSubtype	= UAC_OUTPUT_TERMINAL,
 121	.bTerminalID		= OUTPUT_TERMINAL_ID,
 122	.wTerminalType		= UAC_OUTPUT_TERMINAL_SPEAKER,
 123	.bAssocTerminal		= FEATURE_UNIT_ID,
 124	.bSourceID		= FEATURE_UNIT_ID,
 125};
 126
 127/* B.4.1  Standard AS Interface Descriptor */
 128static struct usb_interface_descriptor as_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_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_header_desc = {
 148	.bLength =		UAC_DT_AS_HEADER_SIZE,
 149	.bDescriptorType =	USB_DT_CS_INTERFACE,
 150	.bDescriptorSubtype =	UAC_AS_GENERAL,
 151	.bTerminalLink =	INPUT_TERMINAL_ID,
 152	.bDelay =		1,
 153	.wFormatTag =		UAC_FORMAT_TYPE_I_PCM,
 154};
 155
 156DECLARE_UAC_FORMAT_TYPE_I_DISCRETE_DESC(1);
 157
 158static struct uac_format_type_i_discrete_descriptor_1 as_type_i_desc = {
 159	.bLength =		UAC_FORMAT_TYPE_I_DISCRETE_DESC_SIZE(1),
 160	.bDescriptorType =	USB_DT_CS_INTERFACE,
 161	.bDescriptorSubtype =	UAC_FORMAT_TYPE,
 162	.bFormatType =		UAC_FORMAT_TYPE_I,
 163	.bSubframeSize =	2,
 164	.bBitResolution =	16,
 165	.bSamFreqType =		1,
 166};
 167
 168/* Standard ISO OUT Endpoint Descriptor */
 169static struct usb_endpoint_descriptor as_out_ep_desc  = {
 170	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
 171	.bDescriptorType =	USB_DT_ENDPOINT,
 172	.bEndpointAddress =	USB_DIR_OUT,
 173	.bmAttributes =		USB_ENDPOINT_SYNC_ADAPTIVE
 174				| USB_ENDPOINT_XFER_ISOC,
 175	.wMaxPacketSize	=	cpu_to_le16(UAC1_OUT_EP_MAX_PACKET_SIZE),
 176	.bInterval =		4,
 177};
 178
 179/* Class-specific AS ISO OUT Endpoint Descriptor */
 180static struct uac_iso_endpoint_descriptor as_iso_out_desc = {
 181	.bLength =		UAC_ISO_ENDPOINT_DESC_SIZE,
 182	.bDescriptorType =	USB_DT_CS_ENDPOINT,
 183	.bDescriptorSubtype =	UAC_EP_GENERAL,
 184	.bmAttributes = 	1,
 185	.bLockDelayUnits =	1,
 186	.wLockDelay =		cpu_to_le16(1),
 187};
 188
 189static struct usb_descriptor_header *f_audio_desc[] = {
 190	(struct usb_descriptor_header *)&ac_interface_desc,
 191	(struct usb_descriptor_header *)&ac_header_desc,
 192
 193	(struct usb_descriptor_header *)&input_terminal_desc,
 194	(struct usb_descriptor_header *)&output_terminal_desc,
 195	(struct usb_descriptor_header *)&feature_unit_desc,
 196
 197	(struct usb_descriptor_header *)&as_interface_alt_0_desc,
 198	(struct usb_descriptor_header *)&as_interface_alt_1_desc,
 199	(struct usb_descriptor_header *)&as_header_desc,
 200
 201	(struct usb_descriptor_header *)&as_type_i_desc,
 202
 203	(struct usb_descriptor_header *)&as_out_ep_desc,
 204	(struct usb_descriptor_header *)&as_iso_out_desc,
 205	NULL,
 206};
 207
 208enum {
 209	STR_AC_IF,
 210	STR_INPUT_TERMINAL,
 211	STR_INPUT_TERMINAL_CH_NAMES,
 212	STR_FEAT_DESC_0,
 213	STR_OUTPUT_TERMINAL,
 214	STR_AS_IF_ALT0,
 215	STR_AS_IF_ALT1,
 216};
 217
 218static struct usb_string strings_uac1[] = {
 219	[STR_AC_IF].s = "AC Interface",
 220	[STR_INPUT_TERMINAL].s = "Input terminal",
 221	[STR_INPUT_TERMINAL_CH_NAMES].s = "Channels",
 222	[STR_FEAT_DESC_0].s = "Volume control & mute",
 223	[STR_OUTPUT_TERMINAL].s = "Output terminal",
 224	[STR_AS_IF_ALT0].s = "AS Interface",
 225	[STR_AS_IF_ALT1].s = "AS Interface",
 226	{ },
 227};
 228
 229static struct usb_gadget_strings str_uac1 = {
 230	.language = 0x0409,	/* en-us */
 231	.strings = strings_uac1,
 232};
 233
 234static struct usb_gadget_strings *uac1_strings[] = {
 235	&str_uac1,
 236	NULL,
 237};
 238
 239/*
 240 * This function is an ALSA sound card following USB Audio Class Spec 1.0.
 241 */
 242
 243/*-------------------------------------------------------------------------*/
 244struct f_audio_buf {
 245	u8 *buf;
 246	int actual;
 247	struct list_head list;
 248};
 249
 250static struct f_audio_buf *f_audio_buffer_alloc(int buf_size)
 251{
 252	struct f_audio_buf *copy_buf;
 253
 254	copy_buf = kzalloc(sizeof *copy_buf, GFP_ATOMIC);
 255	if (!copy_buf)
 256		return ERR_PTR(-ENOMEM);
 257
 258	copy_buf->buf = kzalloc(buf_size, GFP_ATOMIC);
 259	if (!copy_buf->buf) {
 260		kfree(copy_buf);
 261		return ERR_PTR(-ENOMEM);
 262	}
 263
 264	return copy_buf;
 265}
 266
 267static void f_audio_buffer_free(struct f_audio_buf *audio_buf)
 268{
 269	kfree(audio_buf->buf);
 270	kfree(audio_buf);
 271}
 272/*-------------------------------------------------------------------------*/
 273
 274struct f_audio {
 275	struct gaudio			card;
 276
 277	u8 ac_intf, ac_alt;
 278	u8 as_intf, as_alt;
 279
 280	/* endpoints handle full and/or high speeds */
 281	struct usb_ep			*out_ep;
 282
 283	spinlock_t			lock;
 284	struct f_audio_buf *copy_buf;
 285	struct work_struct playback_work;
 286	struct list_head play_queue;
 287
 288	/* Control Set command */
 289	struct list_head cs;
 290	u8 set_cmd;
 291	struct usb_audio_control *set_con;
 292};
 293
 294static inline struct f_audio *func_to_audio(struct usb_function *f)
 295{
 296	return container_of(f, struct f_audio, card.func);
 297}
 298
 299/*-------------------------------------------------------------------------*/
 300
 301static void f_audio_playback_work(struct work_struct *data)
 302{
 303	struct f_audio *audio = container_of(data, struct f_audio,
 304					playback_work);
 305	struct f_audio_buf *play_buf;
 306
 307	spin_lock_irq(&audio->lock);
 308	if (list_empty(&audio->play_queue)) {
 309		spin_unlock_irq(&audio->lock);
 310		return;
 311	}
 312	play_buf = list_first_entry(&audio->play_queue,
 313			struct f_audio_buf, list);
 314	list_del(&play_buf->list);
 315	spin_unlock_irq(&audio->lock);
 316
 317	u_audio_playback(&audio->card, play_buf->buf, play_buf->actual);
 318	f_audio_buffer_free(play_buf);
 319}
 320
 321static int f_audio_out_ep_complete(struct usb_ep *ep, struct usb_request *req)
 322{
 323	struct f_audio *audio = req->context;
 324	struct usb_composite_dev *cdev = audio->card.func.config->cdev;
 325	struct f_audio_buf *copy_buf = audio->copy_buf;
 326	struct f_uac1_legacy_opts *opts;
 327	int audio_buf_size;
 328	int err;
 329
 330	opts = container_of(audio->card.func.fi, struct f_uac1_legacy_opts,
 331			    func_inst);
 332	audio_buf_size = opts->audio_buf_size;
 333
 334	if (!copy_buf)
 335		return -EINVAL;
 336
 337	/* Copy buffer is full, add it to the play_queue */
 338	if (audio_buf_size - copy_buf->actual < req->actual) {
 339		spin_lock_irq(&audio->lock);
 340		list_add_tail(&copy_buf->list, &audio->play_queue);
 341		spin_unlock_irq(&audio->lock);
 342		schedule_work(&audio->playback_work);
 343		copy_buf = f_audio_buffer_alloc(audio_buf_size);
 344		if (IS_ERR(copy_buf))
 345			return -ENOMEM;
 346	}
 347
 348	memcpy(copy_buf->buf + copy_buf->actual, req->buf, req->actual);
 349	copy_buf->actual += req->actual;
 350	audio->copy_buf = copy_buf;
 351
 352	err = usb_ep_queue(ep, req, GFP_ATOMIC);
 353	if (err)
 354		ERROR(cdev, "%s queue req: %d\n", ep->name, err);
 355
 356	return 0;
 357
 358}
 359
 360static void f_audio_complete(struct usb_ep *ep, struct usb_request *req)
 361{
 362	struct f_audio *audio = req->context;
 363	int status = req->status;
 364	u32 data = 0;
 365	struct usb_ep *out_ep = audio->out_ep;
 366
 367	switch (status) {
 368
 369	case 0:				/* normal completion? */
 370		if (ep == out_ep)
 371			f_audio_out_ep_complete(ep, req);
 372		else if (audio->set_con) {
 373			memcpy(&data, req->buf, req->length);
 374			audio->set_con->set(audio->set_con, audio->set_cmd,
 375					le16_to_cpu(data));
 376			audio->set_con = NULL;
 377		}
 378		break;
 379	default:
 380		break;
 381	}
 382}
 383
 384static int audio_set_intf_req(struct usb_function *f,
 385		const struct usb_ctrlrequest *ctrl)
 386{
 387	struct f_audio		*audio = func_to_audio(f);
 388	struct usb_composite_dev *cdev = f->config->cdev;
 389	struct usb_request	*req = cdev->req;
 390	u8			id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 391	u16			len = le16_to_cpu(ctrl->wLength);
 392	u16			w_value = le16_to_cpu(ctrl->wValue);
 393	u8			con_sel = (w_value >> 8) & 0xFF;
 394	u8			cmd = (ctrl->bRequest & 0x0F);
 395	struct usb_audio_control_selector *cs;
 396	struct usb_audio_control *con;
 397
 398	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 399			ctrl->bRequest, w_value, len, id);
 400
 401	list_for_each_entry(cs, &audio->cs, list) {
 402		if (cs->id == id) {
 403			list_for_each_entry(con, &cs->control, list) {
 404				if (con->type == con_sel) {
 405					audio->set_con = con;
 406					break;
 407				}
 408			}
 409			break;
 410		}
 411	}
 412
 413	audio->set_cmd = cmd;
 414	req->context = audio;
 415	req->complete = f_audio_complete;
 416
 417	return len;
 418}
 419
 420static int audio_get_intf_req(struct usb_function *f,
 421		const struct usb_ctrlrequest *ctrl)
 422{
 423	struct f_audio		*audio = func_to_audio(f);
 424	struct usb_composite_dev *cdev = f->config->cdev;
 425	struct usb_request	*req = cdev->req;
 426	int			value = -EOPNOTSUPP;
 427	u8			id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 428	u16			len = le16_to_cpu(ctrl->wLength);
 429	u16			w_value = le16_to_cpu(ctrl->wValue);
 430	u8			con_sel = (w_value >> 8) & 0xFF;
 431	u8			cmd = (ctrl->bRequest & 0x0F);
 432	struct usb_audio_control_selector *cs;
 433	struct usb_audio_control *con;
 434
 435	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 436			ctrl->bRequest, w_value, len, id);
 437
 438	list_for_each_entry(cs, &audio->cs, list) {
 439		if (cs->id == id) {
 440			list_for_each_entry(con, &cs->control, list) {
 441				if (con->type == con_sel && con->get) {
 442					value = con->get(con, cmd);
 443					break;
 444				}
 445			}
 446			break;
 447		}
 448	}
 449
 450	req->context = audio;
 451	req->complete = f_audio_complete;
 452	len = min_t(size_t, sizeof(value), len);
 453	memcpy(req->buf, &value, len);
 454
 455	return len;
 456}
 457
 458static int audio_set_endpoint_req(struct usb_function *f,
 459		const struct usb_ctrlrequest *ctrl)
 460{
 461	struct usb_composite_dev *cdev = f->config->cdev;
 462	int			value = -EOPNOTSUPP;
 463	u16			ep = le16_to_cpu(ctrl->wIndex);
 464	u16			len = le16_to_cpu(ctrl->wLength);
 465	u16			w_value = le16_to_cpu(ctrl->wValue);
 466
 467	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 468			ctrl->bRequest, w_value, len, ep);
 469
 470	switch (ctrl->bRequest) {
 471	case UAC_SET_CUR:
 472		value = len;
 473		break;
 474
 475	case UAC_SET_MIN:
 476		break;
 477
 478	case UAC_SET_MAX:
 479		break;
 480
 481	case UAC_SET_RES:
 482		break;
 483
 484	case UAC_SET_MEM:
 485		break;
 486
 487	default:
 488		break;
 489	}
 490
 491	return value;
 492}
 493
 494static int audio_get_endpoint_req(struct usb_function *f,
 495		const struct usb_ctrlrequest *ctrl)
 496{
 497	struct usb_composite_dev *cdev = f->config->cdev;
 498	int value = -EOPNOTSUPP;
 499	u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 500	u16 len = le16_to_cpu(ctrl->wLength);
 501	u16 w_value = le16_to_cpu(ctrl->wValue);
 502
 503	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 504			ctrl->bRequest, w_value, len, ep);
 505
 506	switch (ctrl->bRequest) {
 507	case UAC_GET_CUR:
 508	case UAC_GET_MIN:
 509	case UAC_GET_MAX:
 510	case UAC_GET_RES:
 511		value = len;
 512		break;
 513	case UAC_GET_MEM:
 514		break;
 515	default:
 516		break;
 517	}
 518
 519	return value;
 520}
 521
 522static int
 523f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 524{
 525	struct usb_composite_dev *cdev = f->config->cdev;
 526	struct usb_request	*req = cdev->req;
 527	int			value = -EOPNOTSUPP;
 528	u16			w_index = le16_to_cpu(ctrl->wIndex);
 529	u16			w_value = le16_to_cpu(ctrl->wValue);
 530	u16			w_length = le16_to_cpu(ctrl->wLength);
 531
 532	/* composite driver infrastructure handles everything; interface
 533	 * activation uses set_alt().
 534	 */
 535	switch (ctrl->bRequestType) {
 536	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 537		value = audio_set_intf_req(f, ctrl);
 538		break;
 539
 540	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 541		value = audio_get_intf_req(f, ctrl);
 542		break;
 543
 544	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 545		value = audio_set_endpoint_req(f, ctrl);
 546		break;
 547
 548	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 549		value = audio_get_endpoint_req(f, ctrl);
 550		break;
 551
 552	default:
 553		ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 554			ctrl->bRequestType, ctrl->bRequest,
 555			w_value, w_index, w_length);
 556	}
 557
 558	/* respond with data transfer or status phase? */
 559	if (value >= 0) {
 560		DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
 561			ctrl->bRequestType, ctrl->bRequest,
 562			w_value, w_index, w_length);
 563		req->zero = 0;
 564		req->length = value;
 565		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 566		if (value < 0)
 567			ERROR(cdev, "audio response on err %d\n", value);
 568	}
 569
 570	/* device either stalls (value < 0) or reports success */
 571	return value;
 572}
 573
 574static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 575{
 576	struct f_audio		*audio = func_to_audio(f);
 577	struct usb_composite_dev *cdev = f->config->cdev;
 578	struct usb_ep *out_ep = audio->out_ep;
 579	struct usb_request *req;
 580	struct f_uac1_legacy_opts *opts;
 581	int req_buf_size, req_count, audio_buf_size;
 582	int i = 0, err = 0;
 583
 584	DBG(cdev, "intf %d, alt %d\n", intf, alt);
 585
 586	opts = container_of(f->fi, struct f_uac1_legacy_opts, func_inst);
 587	req_buf_size = opts->req_buf_size;
 588	req_count = opts->req_count;
 589	audio_buf_size = opts->audio_buf_size;
 590
 591	/* No i/f has more than 2 alt settings */
 592	if (alt > 1) {
 593		ERROR(cdev, "%s:%d Error!\n", __func__, __LINE__);
 594		return -EINVAL;
 595	}
 596
 597	if (intf == audio->ac_intf) {
 598		/* Control I/f has only 1 AltSetting - 0 */
 599		if (alt) {
 600			ERROR(cdev, "%s:%d Error!\n", __func__, __LINE__);
 601			return -EINVAL;
 602		}
 603		return 0;
 604	} else if (intf == audio->as_intf) {
 605		if (alt == 1) {
 606			err = config_ep_by_speed(cdev->gadget, f, out_ep);
 607			if (err)
 608				return err;
 609
 610			usb_ep_enable(out_ep);
 611			audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
 612			if (IS_ERR(audio->copy_buf))
 613				return -ENOMEM;
 614
 615			/*
 616			 * allocate a bunch of read buffers
 617			 * and queue them all at once.
 618			 */
 619			for (i = 0; i < req_count && err == 0; i++) {
 620				req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
 621				if (req) {
 622					req->buf = kzalloc(req_buf_size,
 623							GFP_ATOMIC);
 624					if (req->buf) {
 625						req->length = req_buf_size;
 626						req->context = audio;
 627						req->complete =
 628							f_audio_complete;
 629						err = usb_ep_queue(out_ep,
 630							req, GFP_ATOMIC);
 631						if (err)
 632							ERROR(cdev,
 633							"%s queue req: %d\n",
 634							out_ep->name, err);
 635					} else
 636						err = -ENOMEM;
 637				} else
 638					err = -ENOMEM;
 639			}
 640
 641		} else {
 642			struct f_audio_buf *copy_buf = audio->copy_buf;
 643			if (copy_buf) {
 644				list_add_tail(&copy_buf->list,
 645						&audio->play_queue);
 646				schedule_work(&audio->playback_work);
 647			}
 648		}
 649		audio->as_alt = alt;
 650	}
 651
 652	return err;
 653}
 654
 655static int f_audio_get_alt(struct usb_function *f, unsigned intf)
 656{
 657	struct f_audio		*audio = func_to_audio(f);
 658	struct usb_composite_dev *cdev = f->config->cdev;
 659
 660	if (intf == audio->ac_intf)
 661		return audio->ac_alt;
 662	else if (intf == audio->as_intf)
 663		return audio->as_alt;
 664	else
 665		ERROR(cdev, "%s:%d Invalid Interface %d!\n",
 666		      __func__, __LINE__, intf);
 667
 668	return -EINVAL;
 669}
 670
 671static void f_audio_disable(struct usb_function *f)
 672{
 673	return;
 674}
 675
 676/*-------------------------------------------------------------------------*/
 677
 678static void f_audio_build_desc(struct f_audio *audio)
 679{
 680	struct gaudio *card = &audio->card;
 681	u8 *sam_freq;
 682	int rate;
 683
 684	/* Set channel numbers */
 685	input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
 686	as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
 687
 688	/* Set sample rates */
 689	rate = u_audio_get_playback_rate(card);
 690	sam_freq = as_type_i_desc.tSamFreq[0];
 691	memcpy(sam_freq, &rate, 3);
 692
 693	/* Todo: Set Sample bits and other parameters */
 694
 695	return;
 696}
 697
 698/* audio function driver setup/binding */
 699static int
 700f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 701{
 702	struct usb_composite_dev *cdev = c->cdev;
 703	struct f_audio		*audio = func_to_audio(f);
 704	struct usb_string	*us;
 705	int			status;
 706	struct usb_ep		*ep = NULL;
 707	struct f_uac1_legacy_opts	*audio_opts;
 708
 709	audio_opts = container_of(f->fi, struct f_uac1_legacy_opts, func_inst);
 710	audio->card.gadget = c->cdev->gadget;
 711	/* set up ASLA audio devices */
 712	if (!audio_opts->bound) {
 713		status = gaudio_setup(&audio->card);
 714		if (status < 0)
 715			return status;
 716		audio_opts->bound = true;
 717	}
 718	us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
 719	if (IS_ERR(us))
 720		return PTR_ERR(us);
 721	ac_interface_desc.iInterface = us[STR_AC_IF].id;
 722	input_terminal_desc.iTerminal = us[STR_INPUT_TERMINAL].id;
 723	input_terminal_desc.iChannelNames = us[STR_INPUT_TERMINAL_CH_NAMES].id;
 724	feature_unit_desc.iFeature = us[STR_FEAT_DESC_0].id;
 725	output_terminal_desc.iTerminal = us[STR_OUTPUT_TERMINAL].id;
 726	as_interface_alt_0_desc.iInterface = us[STR_AS_IF_ALT0].id;
 727	as_interface_alt_1_desc.iInterface = us[STR_AS_IF_ALT1].id;
 728
 729
 730	f_audio_build_desc(audio);
 731
 732	/* allocate instance-specific interface IDs, and patch descriptors */
 733	status = usb_interface_id(c, f);
 734	if (status < 0)
 735		goto fail;
 736	ac_interface_desc.bInterfaceNumber = status;
 737	audio->ac_intf = status;
 738	audio->ac_alt = 0;
 739
 740	status = usb_interface_id(c, f);
 741	if (status < 0)
 742		goto fail;
 743	as_interface_alt_0_desc.bInterfaceNumber = status;
 744	as_interface_alt_1_desc.bInterfaceNumber = status;
 745	audio->as_intf = status;
 746	audio->as_alt = 0;
 747
 748	status = -ENODEV;
 749
 750	/* allocate instance-specific endpoints */
 751	ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
 752	if (!ep)
 753		goto fail;
 754	audio->out_ep = ep;
 755	audio->out_ep->desc = &as_out_ep_desc;
 756
 757	/* copy descriptors, and track endpoint copies */
 758	status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL,
 759					NULL);
 760	if (status)
 761		goto fail;
 762	return 0;
 763
 764fail:
 765	gaudio_cleanup(&audio->card);
 766	return status;
 767}
 768
 769/*-------------------------------------------------------------------------*/
 770
 771static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value)
 772{
 773	con->data[cmd] = value;
 774
 775	return 0;
 776}
 777
 778static int generic_get_cmd(struct usb_audio_control *con, u8 cmd)
 779{
 780	return con->data[cmd];
 781}
 782
 783/* Todo: add more control selecotor dynamically */
 784static int control_selector_init(struct f_audio *audio)
 785{
 786	INIT_LIST_HEAD(&audio->cs);
 787	list_add(&feature_unit.list, &audio->cs);
 788
 789	INIT_LIST_HEAD(&feature_unit.control);
 790	list_add(&mute_control.list, &feature_unit.control);
 791	list_add(&volume_control.list, &feature_unit.control);
 792
 793	volume_control.data[UAC__CUR] = 0xffc0;
 794	volume_control.data[UAC__MIN] = 0xe3a0;
 795	volume_control.data[UAC__MAX] = 0xfff0;
 796	volume_control.data[UAC__RES] = 0x0030;
 797
 798	return 0;
 799}
 800
 801static inline
 802struct f_uac1_legacy_opts *to_f_uac1_opts(struct config_item *item)
 803{
 804	return container_of(to_config_group(item), struct f_uac1_legacy_opts,
 805			    func_inst.group);
 806}
 807
 808static void f_uac1_attr_release(struct config_item *item)
 809{
 810	struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);
 811
 812	usb_put_function_instance(&opts->func_inst);
 813}
 814
 815static struct configfs_item_operations f_uac1_item_ops = {
 816	.release	= f_uac1_attr_release,
 817};
 818
 819#define UAC1_INT_ATTRIBUTE(name)					\
 820static ssize_t f_uac1_opts_##name##_show(struct config_item *item,	\
 821					 char *page)			\
 822{									\
 823	struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);		\
 824	int result;							\
 825									\
 826	mutex_lock(&opts->lock);					\
 827	result = sprintf(page, "%u\n", opts->name);			\
 828	mutex_unlock(&opts->lock);					\
 829									\
 830	return result;							\
 831}									\
 832									\
 833static ssize_t f_uac1_opts_##name##_store(struct config_item *item,		\
 834					  const char *page, size_t len)	\
 835{									\
 836	struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);		\
 837	int ret;							\
 838	u32 num;							\
 839									\
 840	mutex_lock(&opts->lock);					\
 841	if (opts->refcnt) {						\
 842		ret = -EBUSY;						\
 843		goto end;						\
 844	}								\
 845									\
 846	ret = kstrtou32(page, 0, &num);					\
 847	if (ret)							\
 848		goto end;						\
 849									\
 850	opts->name = num;						\
 851	ret = len;							\
 852									\
 853end:									\
 854	mutex_unlock(&opts->lock);					\
 855	return ret;							\
 856}									\
 857									\
 858CONFIGFS_ATTR(f_uac1_opts_, name)
 859
 860UAC1_INT_ATTRIBUTE(req_buf_size);
 861UAC1_INT_ATTRIBUTE(req_count);
 862UAC1_INT_ATTRIBUTE(audio_buf_size);
 863
 864#define UAC1_STR_ATTRIBUTE(name)					\
 865static ssize_t f_uac1_opts_##name##_show(struct config_item *item,	\
 866					 char *page)			\
 867{									\
 868	struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);		\
 869	int result;							\
 870									\
 871	mutex_lock(&opts->lock);					\
 872	result = sprintf(page, "%s\n", opts->name);			\
 873	mutex_unlock(&opts->lock);					\
 874									\
 875	return result;							\
 876}									\
 877									\
 878static ssize_t f_uac1_opts_##name##_store(struct config_item *item,	\
 879					  const char *page, size_t len)	\
 880{									\
 881	struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);		\
 882	int ret = -EBUSY;						\
 883	char *tmp;							\
 884									\
 885	mutex_lock(&opts->lock);					\
 886	if (opts->refcnt)						\
 887		goto end;						\
 888									\
 889	tmp = kstrndup(page, len, GFP_KERNEL);				\
 890	if (tmp) {							\
 891		ret = -ENOMEM;						\
 892		goto end;						\
 893	}								\
 894	if (opts->name##_alloc)						\
 895		kfree(opts->name);					\
 896	opts->name##_alloc = true;					\
 897	opts->name = tmp;						\
 898	ret = len;							\
 899									\
 900end:									\
 901	mutex_unlock(&opts->lock);					\
 902	return ret;							\
 903}									\
 904									\
 905CONFIGFS_ATTR(f_uac1_opts_, name)
 906
 907UAC1_STR_ATTRIBUTE(fn_play);
 908UAC1_STR_ATTRIBUTE(fn_cap);
 909UAC1_STR_ATTRIBUTE(fn_cntl);
 910
 911static struct configfs_attribute *f_uac1_attrs[] = {
 912	&f_uac1_opts_attr_req_buf_size,
 913	&f_uac1_opts_attr_req_count,
 914	&f_uac1_opts_attr_audio_buf_size,
 915	&f_uac1_opts_attr_fn_play,
 916	&f_uac1_opts_attr_fn_cap,
 917	&f_uac1_opts_attr_fn_cntl,
 918	NULL,
 919};
 920
 921static const struct config_item_type f_uac1_func_type = {
 922	.ct_item_ops	= &f_uac1_item_ops,
 923	.ct_attrs	= f_uac1_attrs,
 924	.ct_owner	= THIS_MODULE,
 925};
 926
 927static void f_audio_free_inst(struct usb_function_instance *f)
 928{
 929	struct f_uac1_legacy_opts *opts;
 930
 931	opts = container_of(f, struct f_uac1_legacy_opts, func_inst);
 932	if (opts->fn_play_alloc)
 933		kfree(opts->fn_play);
 934	if (opts->fn_cap_alloc)
 935		kfree(opts->fn_cap);
 936	if (opts->fn_cntl_alloc)
 937		kfree(opts->fn_cntl);
 938	kfree(opts);
 939}
 940
 941static struct usb_function_instance *f_audio_alloc_inst(void)
 942{
 943	struct f_uac1_legacy_opts *opts;
 944
 945	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 946	if (!opts)
 947		return ERR_PTR(-ENOMEM);
 948
 949	mutex_init(&opts->lock);
 950	opts->func_inst.free_func_inst = f_audio_free_inst;
 951
 952	config_group_init_type_name(&opts->func_inst.group, "",
 953				    &f_uac1_func_type);
 954
 955	opts->req_buf_size = UAC1_OUT_EP_MAX_PACKET_SIZE;
 956	opts->req_count = UAC1_REQ_COUNT;
 957	opts->audio_buf_size = UAC1_AUDIO_BUF_SIZE;
 958	opts->fn_play = FILE_PCM_PLAYBACK;
 959	opts->fn_cap = FILE_PCM_CAPTURE;
 960	opts->fn_cntl = FILE_CONTROL;
 961	return &opts->func_inst;
 962}
 963
 964static void f_audio_free(struct usb_function *f)
 965{
 966	struct f_audio *audio = func_to_audio(f);
 967	struct f_uac1_legacy_opts *opts;
 968
 969	gaudio_cleanup(&audio->card);
 970	opts = container_of(f->fi, struct f_uac1_legacy_opts, func_inst);
 971	kfree(audio);
 972	mutex_lock(&opts->lock);
 973	--opts->refcnt;
 974	mutex_unlock(&opts->lock);
 975}
 976
 977static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
 978{
 979	usb_free_all_descriptors(f);
 980}
 981
 982static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
 983{
 984	struct f_audio *audio;
 985	struct f_uac1_legacy_opts *opts;
 986
 987	/* allocate and initialize one new instance */
 988	audio = kzalloc(sizeof(*audio), GFP_KERNEL);
 989	if (!audio)
 990		return ERR_PTR(-ENOMEM);
 991
 992	audio->card.func.name = "g_audio";
 993
 994	opts = container_of(fi, struct f_uac1_legacy_opts, func_inst);
 995	mutex_lock(&opts->lock);
 996	++opts->refcnt;
 997	mutex_unlock(&opts->lock);
 998	INIT_LIST_HEAD(&audio->play_queue);
 999	spin_lock_init(&audio->lock);
1000
1001	audio->card.func.bind = f_audio_bind;
1002	audio->card.func.unbind = f_audio_unbind;
1003	audio->card.func.set_alt = f_audio_set_alt;
1004	audio->card.func.get_alt = f_audio_get_alt;
1005	audio->card.func.setup = f_audio_setup;
1006	audio->card.func.disable = f_audio_disable;
1007	audio->card.func.free_func = f_audio_free;
1008
1009	control_selector_init(audio);
1010
1011	INIT_WORK(&audio->playback_work, f_audio_playback_work);
1012
1013	return &audio->card.func;
1014}
1015
1016DECLARE_USB_FUNCTION_INIT(uac1_legacy, f_audio_alloc_inst, f_audio_alloc);
1017MODULE_LICENSE("GPL");
1018MODULE_AUTHOR("Bryan Wu");