f_uac1_legacy.c

   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	struct usb_ep *out_ep = audio->out_ep;
 364
 365	switch (req->status) {
 366	case 0:
 367		if (ep == out_ep) {
 368			f_audio_out_ep_complete(ep, req);
 369		} else if (audio->set_con) {
 370			struct usb_audio_control *con = audio->set_con;
 371			u8 type = con->type;
 372			u32 data;
 373			bool valid_request = false;
 374
 375			switch (type) {
 376			case UAC_FU_MUTE: {
 377				u8 value;
 378
 379				if (req->actual == sizeof(value)) {
 380					memcpy(&value, req->buf, sizeof(value));
 381					data = value;
 382					valid_request = true;
 383				}
 384				break;
 385			}
 386			case UAC_FU_VOLUME: {
 387				__le16 value;
 388
 389				if (req->actual == sizeof(value)) {
 390					memcpy(&value, req->buf, sizeof(value));
 391					data = le16_to_cpu(value);
 392					valid_request = true;
 393				}
 394				break;
 395			}
 396			}
 397
 398			if (valid_request)
 399				con->set(con, audio->set_cmd, data);
 400			else
 401				usb_ep_set_halt(ep);
 402
 403			audio->set_con = NULL;
 404		}
 405		break;
 406	default:
 407		break;
 408	}
 409}
 410
 411static int audio_set_intf_req(struct usb_function *f,
 412		const struct usb_ctrlrequest *ctrl)
 413{
 414	struct f_audio		*audio = func_to_audio(f);
 415	struct usb_composite_dev *cdev = f->config->cdev;
 416	struct usb_request	*req = cdev->req;
 417	u8			id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 418	u16			len = le16_to_cpu(ctrl->wLength);
 419	u16			w_value = le16_to_cpu(ctrl->wValue);
 420	u8			con_sel = (w_value >> 8) & 0xFF;
 421	u8			cmd = (ctrl->bRequest & 0x0F);
 422	struct usb_audio_control_selector *cs;
 423	struct usb_audio_control *con;
 424
 425	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 426			ctrl->bRequest, w_value, len, id);
 427
 428	list_for_each_entry(cs, &audio->cs, list) {
 429		if (cs->id == id) {
 430			list_for_each_entry(con, &cs->control, list) {
 431				if (con->type == con_sel) {
 432					audio->set_con = con;
 433					break;
 434				}
 435			}
 436			break;
 437		}
 438	}
 439
 440	audio->set_cmd = cmd;
 441	req->context = audio;
 442	req->complete = f_audio_complete;
 443
 444	return len;
 445}
 446
 447static int audio_get_intf_req(struct usb_function *f,
 448		const struct usb_ctrlrequest *ctrl)
 449{
 450	struct f_audio		*audio = func_to_audio(f);
 451	struct usb_composite_dev *cdev = f->config->cdev;
 452	struct usb_request	*req = cdev->req;
 453	int			value = -EOPNOTSUPP;
 454	u8			id = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 455	u16			len = le16_to_cpu(ctrl->wLength);
 456	u16			w_value = le16_to_cpu(ctrl->wValue);
 457	u8			con_sel = (w_value >> 8) & 0xFF;
 458	u8			cmd = (ctrl->bRequest & 0x0F);
 459	struct usb_audio_control_selector *cs;
 460	struct usb_audio_control *con;
 461
 462	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, entity %d\n",
 463			ctrl->bRequest, w_value, len, id);
 464
 465	list_for_each_entry(cs, &audio->cs, list) {
 466		if (cs->id == id) {
 467			list_for_each_entry(con, &cs->control, list) {
 468				if (con->type == con_sel && con->get) {
 469					value = con->get(con, cmd);
 470					break;
 471				}
 472			}
 473			break;
 474		}
 475	}
 476
 477	req->context = audio;
 478	req->complete = f_audio_complete;
 479	len = min_t(size_t, sizeof(value), len);
 480	memcpy(req->buf, &value, len);
 481
 482	return len;
 483}
 484
 485static int audio_set_endpoint_req(struct usb_function *f,
 486		const struct usb_ctrlrequest *ctrl)
 487{
 488	struct usb_composite_dev *cdev = f->config->cdev;
 489	int			value = -EOPNOTSUPP;
 490	u16			ep = le16_to_cpu(ctrl->wIndex);
 491	u16			len = le16_to_cpu(ctrl->wLength);
 492	u16			w_value = le16_to_cpu(ctrl->wValue);
 493
 494	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 495			ctrl->bRequest, w_value, len, ep);
 496
 497	switch (ctrl->bRequest) {
 498	case UAC_SET_CUR:
 499		value = len;
 500		break;
 501
 502	case UAC_SET_MIN:
 503		break;
 504
 505	case UAC_SET_MAX:
 506		break;
 507
 508	case UAC_SET_RES:
 509		break;
 510
 511	case UAC_SET_MEM:
 512		break;
 513
 514	default:
 515		break;
 516	}
 517
 518	return value;
 519}
 520
 521static int audio_get_endpoint_req(struct usb_function *f,
 522		const struct usb_ctrlrequest *ctrl)
 523{
 524	struct usb_composite_dev *cdev = f->config->cdev;
 525	int value = -EOPNOTSUPP;
 526	u8 ep = ((le16_to_cpu(ctrl->wIndex) >> 8) & 0xFF);
 527	u16 len = le16_to_cpu(ctrl->wLength);
 528	u16 w_value = le16_to_cpu(ctrl->wValue);
 529
 530	DBG(cdev, "bRequest 0x%x, w_value 0x%04x, len %d, endpoint %d\n",
 531			ctrl->bRequest, w_value, len, ep);
 532
 533	switch (ctrl->bRequest) {
 534	case UAC_GET_CUR:
 535	case UAC_GET_MIN:
 536	case UAC_GET_MAX:
 537	case UAC_GET_RES:
 538		value = len;
 539		break;
 540	case UAC_GET_MEM:
 541		break;
 542	default:
 543		break;
 544	}
 545
 546	return value;
 547}
 548
 549static int
 550f_audio_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 551{
 552	struct usb_composite_dev *cdev = f->config->cdev;
 553	struct usb_request	*req = cdev->req;
 554	int			value = -EOPNOTSUPP;
 555	u16			w_index = le16_to_cpu(ctrl->wIndex);
 556	u16			w_value = le16_to_cpu(ctrl->wValue);
 557	u16			w_length = le16_to_cpu(ctrl->wLength);
 558
 559	/* composite driver infrastructure handles everything; interface
 560	 * activation uses set_alt().
 561	 */
 562	switch (ctrl->bRequestType) {
 563	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 564		value = audio_set_intf_req(f, ctrl);
 565		break;
 566
 567	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE:
 568		value = audio_get_intf_req(f, ctrl);
 569		break;
 570
 571	case USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 572		value = audio_set_endpoint_req(f, ctrl);
 573		break;
 574
 575	case USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT:
 576		value = audio_get_endpoint_req(f, ctrl);
 577		break;
 578
 579	default:
 580		ERROR(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 581			ctrl->bRequestType, ctrl->bRequest,
 582			w_value, w_index, w_length);
 583	}
 584
 585	/* respond with data transfer or status phase? */
 586	if (value >= 0) {
 587		DBG(cdev, "audio req%02x.%02x v%04x i%04x l%d\n",
 588			ctrl->bRequestType, ctrl->bRequest,
 589			w_value, w_index, w_length);
 590		req->zero = 0;
 591		req->length = value;
 592		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 593		if (value < 0)
 594			ERROR(cdev, "audio response on err %d\n", value);
 595	}
 596
 597	/* device either stalls (value < 0) or reports success */
 598	return value;
 599}
 600
 601static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 602{
 603	struct f_audio		*audio = func_to_audio(f);
 604	struct usb_composite_dev *cdev = f->config->cdev;
 605	struct usb_ep *out_ep = audio->out_ep;
 606	struct usb_request *req;
 607	struct f_uac1_legacy_opts *opts;
 608	int req_buf_size, req_count, audio_buf_size;
 609	int i = 0, err = 0;
 610
 611	DBG(cdev, "intf %d, alt %d\n", intf, alt);
 612
 613	opts = container_of(f->fi, struct f_uac1_legacy_opts, func_inst);
 614	req_buf_size = opts->req_buf_size;
 615	req_count = opts->req_count;
 616	audio_buf_size = opts->audio_buf_size;
 617
 618	/* No i/f has more than 2 alt settings */
 619	if (alt > 1) {
 620		ERROR(cdev, "%s:%d Error!\n", __func__, __LINE__);
 621		return -EINVAL;
 622	}
 623
 624	if (intf == audio->ac_intf) {
 625		/* Control I/f has only 1 AltSetting - 0 */
 626		if (alt) {
 627			ERROR(cdev, "%s:%d Error!\n", __func__, __LINE__);
 628			return -EINVAL;
 629		}
 630		return 0;
 631	} else if (intf == audio->as_intf) {
 632		if (alt == 1) {
 633			err = config_ep_by_speed(cdev->gadget, f, out_ep);
 634			if (err)
 635				return err;
 636
 637			usb_ep_enable(out_ep);
 638			audio->copy_buf = f_audio_buffer_alloc(audio_buf_size);
 639			if (IS_ERR(audio->copy_buf))
 640				return -ENOMEM;
 641
 642			/*
 643			 * allocate a bunch of read buffers
 644			 * and queue them all at once.
 645			 */
 646			for (i = 0; i < req_count && err == 0; i++) {
 647				req = usb_ep_alloc_request(out_ep, GFP_ATOMIC);
 648				if (req) {
 649					req->buf = kzalloc(req_buf_size,
 650							GFP_ATOMIC);
 651					if (req->buf) {
 652						req->length = req_buf_size;
 653						req->context = audio;
 654						req->complete =
 655							f_audio_complete;
 656						err = usb_ep_queue(out_ep,
 657							req, GFP_ATOMIC);
 658						if (err)
 659							ERROR(cdev,
 660							"%s queue req: %d\n",
 661							out_ep->name, err);
 662					} else
 663						err = -ENOMEM;
 664				} else
 665					err = -ENOMEM;
 666			}
 667
 668		} else {
 669			struct f_audio_buf *copy_buf = audio->copy_buf;
 670			if (copy_buf) {
 671				list_add_tail(&copy_buf->list,
 672						&audio->play_queue);
 673				schedule_work(&audio->playback_work);
 674			}
 675		}
 676		audio->as_alt = alt;
 677	}
 678
 679	return err;
 680}
 681
 682static int f_audio_get_alt(struct usb_function *f, unsigned intf)
 683{
 684	struct f_audio		*audio = func_to_audio(f);
 685	struct usb_composite_dev *cdev = f->config->cdev;
 686
 687	if (intf == audio->ac_intf)
 688		return audio->ac_alt;
 689	else if (intf == audio->as_intf)
 690		return audio->as_alt;
 691	else
 692		ERROR(cdev, "%s:%d Invalid Interface %d!\n",
 693		      __func__, __LINE__, intf);
 694
 695	return -EINVAL;
 696}
 697
 698static void f_audio_disable(struct usb_function *f)
 699{
 700	return;
 701}
 702
 703/*-------------------------------------------------------------------------*/
 704
 705static void f_audio_build_desc(struct f_audio *audio)
 706{
 707	struct gaudio *card = &audio->card;
 708	u8 *sam_freq;
 709	int rate;
 710
 711	/* Set channel numbers */
 712	input_terminal_desc.bNrChannels = u_audio_get_playback_channels(card);
 713	as_type_i_desc.bNrChannels = u_audio_get_playback_channels(card);
 714
 715	/* Set sample rates */
 716	rate = u_audio_get_playback_rate(card);
 717	sam_freq = as_type_i_desc.tSamFreq[0];
 718	memcpy(sam_freq, &rate, 3);
 719
 720	/* Todo: Set Sample bits and other parameters */
 721
 722	return;
 723}
 724
 725/* audio function driver setup/binding */
 726static int
 727f_audio_bind(struct usb_configuration *c, struct usb_function *f)
 728{
 729	struct usb_composite_dev *cdev = c->cdev;
 730	struct f_audio		*audio = func_to_audio(f);
 731	struct usb_string	*us;
 732	int			status;
 733	struct usb_ep		*ep = NULL;
 734	struct f_uac1_legacy_opts	*audio_opts;
 735
 736	audio_opts = container_of(f->fi, struct f_uac1_legacy_opts, func_inst);
 737	audio->card.gadget = c->cdev->gadget;
 738	/* set up ASLA audio devices */
 739	if (!audio_opts->bound) {
 740		status = gaudio_setup(&audio->card);
 741		if (status < 0)
 742			return status;
 743		audio_opts->bound = true;
 744	}
 745	us = usb_gstrings_attach(cdev, uac1_strings, ARRAY_SIZE(strings_uac1));
 746	if (IS_ERR(us))
 747		return PTR_ERR(us);
 748	ac_interface_desc.iInterface = us[STR_AC_IF].id;
 749	input_terminal_desc.iTerminal = us[STR_INPUT_TERMINAL].id;
 750	input_terminal_desc.iChannelNames = us[STR_INPUT_TERMINAL_CH_NAMES].id;
 751	feature_unit_desc.iFeature = us[STR_FEAT_DESC_0].id;
 752	output_terminal_desc.iTerminal = us[STR_OUTPUT_TERMINAL].id;
 753	as_interface_alt_0_desc.iInterface = us[STR_AS_IF_ALT0].id;
 754	as_interface_alt_1_desc.iInterface = us[STR_AS_IF_ALT1].id;
 755
 756
 757	f_audio_build_desc(audio);
 758
 759	/* allocate instance-specific interface IDs, and patch descriptors */
 760	status = usb_interface_id(c, f);
 761	if (status < 0)
 762		goto fail;
 763	ac_interface_desc.bInterfaceNumber = status;
 764	audio->ac_intf = status;
 765	audio->ac_alt = 0;
 766
 767	status = usb_interface_id(c, f);
 768	if (status < 0)
 769		goto fail;
 770	as_interface_alt_0_desc.bInterfaceNumber = status;
 771	as_interface_alt_1_desc.bInterfaceNumber = status;
 772	audio->as_intf = status;
 773	audio->as_alt = 0;
 774
 775	status = -ENODEV;
 776
 777	/* allocate instance-specific endpoints */
 778	ep = usb_ep_autoconfig(cdev->gadget, &as_out_ep_desc);
 779	if (!ep)
 780		goto fail;
 781	audio->out_ep = ep;
 782	audio->out_ep->desc = &as_out_ep_desc;
 783
 784	/* copy descriptors, and track endpoint copies */
 785	status = usb_assign_descriptors(f, f_audio_desc, f_audio_desc, NULL,
 786					NULL);
 787	if (status)
 788		goto fail;
 789	return 0;
 790
 791fail:
 792	gaudio_cleanup(&audio->card);
 793	return status;
 794}
 795
 796/*-------------------------------------------------------------------------*/
 797
 798static int generic_set_cmd(struct usb_audio_control *con, u8 cmd, int value)
 799{
 800	con->data[cmd] = value;
 801
 802	return 0;
 803}
 804
 805static int generic_get_cmd(struct usb_audio_control *con, u8 cmd)
 806{
 807	return con->data[cmd];
 808}
 809
 810/* Todo: add more control selecotor dynamically */
 811static int control_selector_init(struct f_audio *audio)
 812{
 813	INIT_LIST_HEAD(&audio->cs);
 814	list_add(&feature_unit.list, &audio->cs);
 815
 816	INIT_LIST_HEAD(&feature_unit.control);
 817	list_add(&mute_control.list, &feature_unit.control);
 818	list_add(&volume_control.list, &feature_unit.control);
 819
 820	volume_control.data[UAC__CUR] = 0xffc0;
 821	volume_control.data[UAC__MIN] = 0xe3a0;
 822	volume_control.data[UAC__MAX] = 0xfff0;
 823	volume_control.data[UAC__RES] = 0x0030;
 824
 825	return 0;
 826}
 827
 828static inline
 829struct f_uac1_legacy_opts *to_f_uac1_opts(struct config_item *item)
 830{
 831	return container_of(to_config_group(item), struct f_uac1_legacy_opts,
 832			    func_inst.group);
 833}
 834
 835static void f_uac1_attr_release(struct config_item *item)
 836{
 837	struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);
 838
 839	usb_put_function_instance(&opts->func_inst);
 840}
 841
 842static struct configfs_item_operations f_uac1_item_ops = {
 843	.release	= f_uac1_attr_release,
 844};
 845
 846#define UAC1_INT_ATTRIBUTE(name)					\
 847static ssize_t f_uac1_opts_##name##_show(struct config_item *item,	\
 848					 char *page)			\
 849{									\
 850	struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);		\
 851	int result;							\
 852									\
 853	mutex_lock(&opts->lock);					\
 854	result = sprintf(page, "%u\n", opts->name);			\
 855	mutex_unlock(&opts->lock);					\
 856									\
 857	return result;							\
 858}									\
 859									\
 860static ssize_t f_uac1_opts_##name##_store(struct config_item *item,		\
 861					  const char *page, size_t len)	\
 862{									\
 863	struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);		\
 864	int ret;							\
 865	u32 num;							\
 866									\
 867	mutex_lock(&opts->lock);					\
 868	if (opts->refcnt) {						\
 869		ret = -EBUSY;						\
 870		goto end;						\
 871	}								\
 872									\
 873	ret = kstrtou32(page, 0, &num);					\
 874	if (ret)							\
 875		goto end;						\
 876									\
 877	opts->name = num;						\
 878	ret = len;							\
 879									\
 880end:									\
 881	mutex_unlock(&opts->lock);					\
 882	return ret;							\
 883}									\
 884									\
 885CONFIGFS_ATTR(f_uac1_opts_, name)
 886
 887UAC1_INT_ATTRIBUTE(req_buf_size);
 888UAC1_INT_ATTRIBUTE(req_count);
 889UAC1_INT_ATTRIBUTE(audio_buf_size);
 890
 891#define UAC1_STR_ATTRIBUTE(name)					\
 892static ssize_t f_uac1_opts_##name##_show(struct config_item *item,	\
 893					 char *page)			\
 894{									\
 895	struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);		\
 896	int result;							\
 897									\
 898	mutex_lock(&opts->lock);					\
 899	result = sprintf(page, "%s\n", opts->name);			\
 900	mutex_unlock(&opts->lock);					\
 901									\
 902	return result;							\
 903}									\
 904									\
 905static ssize_t f_uac1_opts_##name##_store(struct config_item *item,	\
 906					  const char *page, size_t len)	\
 907{									\
 908	struct f_uac1_legacy_opts *opts = to_f_uac1_opts(item);		\
 909	int ret = -EBUSY;						\
 910	char *tmp;							\
 911									\
 912	mutex_lock(&opts->lock);					\
 913	if (opts->refcnt)						\
 914		goto end;						\
 915									\
 916	tmp = kstrndup(page, len, GFP_KERNEL);				\
 917	if (tmp) {							\
 918		ret = -ENOMEM;						\
 919		goto end;						\
 920	}								\
 921	if (opts->name##_alloc)						\
 922		kfree(opts->name);					\
 923	opts->name##_alloc = true;					\
 924	opts->name = tmp;						\
 925	ret = len;							\
 926									\
 927end:									\
 928	mutex_unlock(&opts->lock);					\
 929	return ret;							\
 930}									\
 931									\
 932CONFIGFS_ATTR(f_uac1_opts_, name)
 933
 934UAC1_STR_ATTRIBUTE(fn_play);
 935UAC1_STR_ATTRIBUTE(fn_cap);
 936UAC1_STR_ATTRIBUTE(fn_cntl);
 937
 938static struct configfs_attribute *f_uac1_attrs[] = {
 939	&f_uac1_opts_attr_req_buf_size,
 940	&f_uac1_opts_attr_req_count,
 941	&f_uac1_opts_attr_audio_buf_size,
 942	&f_uac1_opts_attr_fn_play,
 943	&f_uac1_opts_attr_fn_cap,
 944	&f_uac1_opts_attr_fn_cntl,
 945	NULL,
 946};
 947
 948static const struct config_item_type f_uac1_func_type = {
 949	.ct_item_ops	= &f_uac1_item_ops,
 950	.ct_attrs	= f_uac1_attrs,
 951	.ct_owner	= THIS_MODULE,
 952};
 953
 954static void f_audio_free_inst(struct usb_function_instance *f)
 955{
 956	struct f_uac1_legacy_opts *opts;
 957
 958	opts = container_of(f, struct f_uac1_legacy_opts, func_inst);
 959	if (opts->fn_play_alloc)
 960		kfree(opts->fn_play);
 961	if (opts->fn_cap_alloc)
 962		kfree(opts->fn_cap);
 963	if (opts->fn_cntl_alloc)
 964		kfree(opts->fn_cntl);
 965	kfree(opts);
 966}
 967
 968static struct usb_function_instance *f_audio_alloc_inst(void)
 969{
 970	struct f_uac1_legacy_opts *opts;
 971
 972	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 973	if (!opts)
 974		return ERR_PTR(-ENOMEM);
 975
 976	mutex_init(&opts->lock);
 977	opts->func_inst.free_func_inst = f_audio_free_inst;
 978
 979	config_group_init_type_name(&opts->func_inst.group, "",
 980				    &f_uac1_func_type);
 981
 982	opts->req_buf_size = UAC1_OUT_EP_MAX_PACKET_SIZE;
 983	opts->req_count = UAC1_REQ_COUNT;
 984	opts->audio_buf_size = UAC1_AUDIO_BUF_SIZE;
 985	opts->fn_play = FILE_PCM_PLAYBACK;
 986	opts->fn_cap = FILE_PCM_CAPTURE;
 987	opts->fn_cntl = FILE_CONTROL;
 988	return &opts->func_inst;
 989}
 990
 991static void f_audio_free(struct usb_function *f)
 992{
 993	struct f_audio *audio = func_to_audio(f);
 994	struct f_uac1_legacy_opts *opts;
 995
 996	gaudio_cleanup(&audio->card);
 997	opts = container_of(f->fi, struct f_uac1_legacy_opts, func_inst);
 998	kfree(audio);
 999	mutex_lock(&opts->lock);
1000	--opts->refcnt;
1001	mutex_unlock(&opts->lock);
1002}
1003
1004static void f_audio_unbind(struct usb_configuration *c, struct usb_function *f)
1005{
1006	usb_free_all_descriptors(f);
1007}
1008
1009static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
1010{
1011	struct f_audio *audio;
1012	struct f_uac1_legacy_opts *opts;
1013
1014	/* allocate and initialize one new instance */
1015	audio = kzalloc(sizeof(*audio), GFP_KERNEL);
1016	if (!audio)
1017		return ERR_PTR(-ENOMEM);
1018
1019	audio->card.func.name = "g_audio";
1020
1021	opts = container_of(fi, struct f_uac1_legacy_opts, func_inst);
1022	mutex_lock(&opts->lock);
1023	++opts->refcnt;
1024	mutex_unlock(&opts->lock);
1025	INIT_LIST_HEAD(&audio->play_queue);
1026	spin_lock_init(&audio->lock);
1027
1028	audio->card.func.bind = f_audio_bind;
1029	audio->card.func.unbind = f_audio_unbind;
1030	audio->card.func.set_alt = f_audio_set_alt;
1031	audio->card.func.get_alt = f_audio_get_alt;
1032	audio->card.func.setup = f_audio_setup;
1033	audio->card.func.disable = f_audio_disable;
1034	audio->card.func.free_func = f_audio_free;
1035
1036	control_selector_init(audio);
1037
1038	INIT_WORK(&audio->playback_work, f_audio_playback_work);
1039
1040	return &audio->card.func;
1041}
1042
1043DECLARE_USB_FUNCTION_INIT(uac1_legacy, f_audio_alloc_inst, f_audio_alloc);
1044MODULE_DESCRIPTION("USB Audio class function driver");
1045MODULE_LICENSE("GPL");
1046MODULE_AUTHOR("Bryan Wu");