1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   3 */
   4
   5#include <linux/gfp.h>
   6#include <linux/init.h>
   7#include <linux/ratelimit.h>
   8#include <linux/usb.h>
   9#include <linux/usb/audio.h>
  10#include <linux/slab.h>
  11
  12#include <sound/core.h>
  13#include <sound/pcm.h>
  14#include <sound/pcm_params.h>
  15
  16#include "usbaudio.h"
  17#include "helper.h"
  18#include "card.h"
  19#include "endpoint.h"
  20#include "pcm.h"
  21#include "clock.h"
  22#include "quirks.h"
  23
  24enum {
  25	EP_STATE_STOPPED,
  26	EP_STATE_RUNNING,
  27	EP_STATE_STOPPING,
  28};
  29
  30/* interface refcounting */
  31struct snd_usb_iface_ref {
  32	unsigned char iface;
  33	bool need_setup;
  34	int opened;
  35	int altset;
  36	struct list_head list;
  37};
  38
  39/* clock refcounting */
  40struct snd_usb_clock_ref {
  41	unsigned char clock;
  42	atomic_t locked;
  43	int opened;
  44	int rate;
  45	bool need_setup;
  46	struct list_head list;
  47};
  48
  49/*
  50 * snd_usb_endpoint is a model that abstracts everything related to an
  51 * USB endpoint and its streaming.
  52 *
  53 * There are functions to activate and deactivate the streaming URBs and
  54 * optional callbacks to let the pcm logic handle the actual content of the
  55 * packets for playback and record. Thus, the bus streaming and the audio
  56 * handlers are fully decoupled.
  57 *
  58 * There are two different types of endpoints in audio applications.
  59 *
  60 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both
  61 * inbound and outbound traffic.
  62 *
  63 * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and
  64 * expect the payload to carry Q10.14 / Q16.16 formatted sync information
  65 * (3 or 4 bytes).
  66 *
  67 * Each endpoint has to be configured prior to being used by calling
  68 * snd_usb_endpoint_set_params().
  69 *
  70 * The model incorporates a reference counting, so that multiple users
  71 * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and
  72 * only the first user will effectively start the URBs, and only the last
  73 * one to stop it will tear the URBs down again.
  74 */
  75
  76/*
  77 * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
  78 * this will overflow at approx 524 kHz
  79 */
  80static inline unsigned get_usb_full_speed_rate(unsigned int rate)
  81{
  82	return ((rate << 13) + 62) / 125;
  83}
  84
  85/*
  86 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
  87 * this will overflow at approx 4 MHz
  88 */
  89static inline unsigned get_usb_high_speed_rate(unsigned int rate)
  90{
  91	return ((rate << 10) + 62) / 125;
  92}
  93
  94/*
  95 * release a urb data
  96 */
  97static void release_urb_ctx(struct snd_urb_ctx *u)
  98{
  99	if (u->urb && u->buffer_size)
 100		usb_free_coherent(u->ep->chip->dev, u->buffer_size,
 101				  u->urb->transfer_buffer,
 102				  u->urb->transfer_dma);
 103	usb_free_urb(u->urb);
 104	u->urb = NULL;
 105	u->buffer_size = 0;
 106}
 107
 108static const char *usb_error_string(int err)
 109{
 110	switch (err) {
 111	case -ENODEV:
 112		return "no device";
 113	case -ENOENT:
 114		return "endpoint not enabled";
 115	case -EPIPE:
 116		return "endpoint stalled";
 117	case -ENOSPC:
 118		return "not enough bandwidth";
 119	case -ESHUTDOWN:
 120		return "device disabled";
 121	case -EHOSTUNREACH:
 122		return "device suspended";
 123	case -EINVAL:
 124	case -EAGAIN:
 125	case -EFBIG:
 126	case -EMSGSIZE:
 127		return "internal error";
 128	default:
 129		return "unknown error";
 130	}
 131}
 132
 133static inline bool ep_state_running(struct snd_usb_endpoint *ep)
 134{
 135	return atomic_read(&ep->state) == EP_STATE_RUNNING;
 136}
 137
 138static inline bool ep_state_update(struct snd_usb_endpoint *ep, int old, int new)
 139{
 140	return atomic_try_cmpxchg(&ep->state, &old, new);
 141}
 142
 143/**
 144 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type
 145 *
 146 * @ep: The snd_usb_endpoint
 147 *
 148 * Determine whether an endpoint is driven by an implicit feedback
 149 * data endpoint source.
 150 */
 151int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep)
 152{
 153	return  ep->implicit_fb_sync && usb_pipeout(ep->pipe);
 
 
 
 154}
 155
 156/*
 157 * Return the number of samples to be sent in the next packet
 158 * for streaming based on information derived from sync endpoints
 
 159 *
 160 * This won't be used for implicit feedback which takes the packet size
 161 * returned from the sync source
 162 */
 163static int slave_next_packet_size(struct snd_usb_endpoint *ep,
 164				  unsigned int avail)
 165{
 166	unsigned long flags;
 167	unsigned int phase;
 168	int ret;
 169
 170	if (ep->fill_max)
 171		return ep->maxframesize;
 172
 173	spin_lock_irqsave(&ep->lock, flags);
 174	phase = (ep->phase & 0xffff) + (ep->freqm << ep->datainterval);
 175	ret = min(phase >> 16, ep->maxframesize);
 176	if (avail && ret >= avail)
 177		ret = -EAGAIN;
 178	else
 179		ep->phase = phase;
 180	spin_unlock_irqrestore(&ep->lock, flags);
 181
 182	return ret;
 183}
 184
 185/*
 186 * Return the number of samples to be sent in the next packet
 187 * for adaptive and synchronous endpoints
 188 */
 189static int next_packet_size(struct snd_usb_endpoint *ep, unsigned int avail)
 190{
 191	unsigned int sample_accum;
 192	int ret;
 193
 194	if (ep->fill_max)
 195		return ep->maxframesize;
 196
 197	sample_accum = ep->sample_accum + ep->sample_rem;
 198	if (sample_accum >= ep->pps) {
 199		sample_accum -= ep->pps;
 200		ret = ep->packsize[1];
 201	} else {
 202		ret = ep->packsize[0];
 203	}
 204	if (avail && ret >= avail)
 205		ret = -EAGAIN;
 206	else
 207		ep->sample_accum = sample_accum;
 208
 209	return ret;
 210}
 211
 212/*
 213 * snd_usb_endpoint_next_packet_size: Return the number of samples to be sent
 214 * in the next packet
 215 *
 216 * If the size is equal or exceeds @avail, don't proceed but return -EAGAIN
 217 * Exception: @avail = 0 for skipping the check.
 218 */
 219int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep,
 220				      struct snd_urb_ctx *ctx, int idx,
 221				      unsigned int avail)
 222{
 223	unsigned int packet;
 224
 225	packet = ctx->packet_size[idx];
 226	if (packet) {
 227		if (avail && packet >= avail)
 228			return -EAGAIN;
 229		return packet;
 230	}
 231
 232	if (ep->sync_source)
 233		return slave_next_packet_size(ep, avail);
 234	else
 235		return next_packet_size(ep, avail);
 236}
 237
 238static void call_retire_callback(struct snd_usb_endpoint *ep,
 239				 struct urb *urb)
 240{
 241	struct snd_usb_substream *data_subs;
 242
 243	data_subs = READ_ONCE(ep->data_subs);
 244	if (data_subs && ep->retire_data_urb)
 245		ep->retire_data_urb(data_subs, urb);
 246}
 247
 248static void retire_outbound_urb(struct snd_usb_endpoint *ep,
 249				struct snd_urb_ctx *urb_ctx)
 250{
 251	call_retire_callback(ep, urb_ctx->urb);
 
 252}
 253
 254static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
 255				    struct snd_usb_endpoint *sender,
 256				    const struct urb *urb);
 257
 258static void retire_inbound_urb(struct snd_usb_endpoint *ep,
 259			       struct snd_urb_ctx *urb_ctx)
 260{
 261	struct urb *urb = urb_ctx->urb;
 262	struct snd_usb_endpoint *sync_sink;
 263
 264	if (unlikely(ep->skip_packets > 0)) {
 265		ep->skip_packets--;
 266		return;
 267	}
 268
 269	sync_sink = READ_ONCE(ep->sync_sink);
 270	if (sync_sink)
 271		snd_usb_handle_sync_urb(sync_sink, ep, urb);
 272
 273	call_retire_callback(ep, urb);
 274}
 275
 276static inline bool has_tx_length_quirk(struct snd_usb_audio *chip)
 277{
 278	return chip->quirk_flags & QUIRK_FLAG_TX_LENGTH;
 279}
 280
 281static void prepare_silent_urb(struct snd_usb_endpoint *ep,
 282			       struct snd_urb_ctx *ctx)
 283{
 284	struct urb *urb = ctx->urb;
 285	unsigned int offs = 0;
 286	unsigned int extra = 0;
 287	__le32 packet_length;
 288	int i;
 289
 290	/* For tx_length_quirk, put packet length at start of packet */
 291	if (has_tx_length_quirk(ep->chip))
 292		extra = sizeof(packet_length);
 293
 294	for (i = 0; i < ctx->packets; ++i) {
 295		unsigned int offset;
 296		unsigned int length;
 297		int counts;
 298
 299		counts = snd_usb_endpoint_next_packet_size(ep, ctx, i, 0);
 
 
 
 
 300		length = counts * ep->stride; /* number of silent bytes */
 301		offset = offs * ep->stride + extra * i;
 302		urb->iso_frame_desc[i].offset = offset;
 303		urb->iso_frame_desc[i].length = length + extra;
 304		if (extra) {
 305			packet_length = cpu_to_le32(length);
 306			memcpy(urb->transfer_buffer + offset,
 307			       &packet_length, sizeof(packet_length));
 308		}
 309		memset(urb->transfer_buffer + offset + extra,
 310		       ep->silence_value, length);
 311		offs += counts;
 312	}
 313
 314	urb->number_of_packets = ctx->packets;
 315	urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra;
 316	ctx->queued = 0;
 317}
 318
 319/*
 320 * Prepare a PLAYBACK urb for submission to the bus.
 321 */
 322static int prepare_outbound_urb(struct snd_usb_endpoint *ep,
 323				struct snd_urb_ctx *ctx,
 324				bool in_stream_lock)
 325{
 326	struct urb *urb = ctx->urb;
 327	unsigned char *cp = urb->transfer_buffer;
 328	struct snd_usb_substream *data_subs;
 329
 330	urb->dev = ep->chip->dev; /* we need to set this at each time */
 331
 332	switch (ep->type) {
 333	case SND_USB_ENDPOINT_TYPE_DATA:
 334		data_subs = READ_ONCE(ep->data_subs);
 335		if (data_subs && ep->prepare_data_urb)
 336			return ep->prepare_data_urb(data_subs, urb, in_stream_lock);
 337		/* no data provider, so send silence */
 338		prepare_silent_urb(ep, ctx);
 
 339		break;
 340
 341	case SND_USB_ENDPOINT_TYPE_SYNC:
 342		if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) {
 343			/*
 344			 * fill the length and offset of each urb descriptor.
 345			 * the fixed 12.13 frequency is passed as 16.16 through the pipe.
 346			 */
 347			urb->iso_frame_desc[0].length = 4;
 348			urb->iso_frame_desc[0].offset = 0;
 349			cp[0] = ep->freqn;
 350			cp[1] = ep->freqn >> 8;
 351			cp[2] = ep->freqn >> 16;
 352			cp[3] = ep->freqn >> 24;
 353		} else {
 354			/*
 355			 * fill the length and offset of each urb descriptor.
 356			 * the fixed 10.14 frequency is passed through the pipe.
 357			 */
 358			urb->iso_frame_desc[0].length = 3;
 359			urb->iso_frame_desc[0].offset = 0;
 360			cp[0] = ep->freqn >> 2;
 361			cp[1] = ep->freqn >> 10;
 362			cp[2] = ep->freqn >> 18;
 363		}
 364
 365		break;
 366	}
 367	return 0;
 368}
 369
 370/*
 371 * Prepare a CAPTURE or SYNC urb for submission to the bus.
 372 */
 373static int prepare_inbound_urb(struct snd_usb_endpoint *ep,
 374			       struct snd_urb_ctx *urb_ctx)
 375{
 376	int i, offs;
 377	struct urb *urb = urb_ctx->urb;
 378
 379	urb->dev = ep->chip->dev; /* we need to set this at each time */
 380
 381	switch (ep->type) {
 382	case SND_USB_ENDPOINT_TYPE_DATA:
 383		offs = 0;
 384		for (i = 0; i < urb_ctx->packets; i++) {
 385			urb->iso_frame_desc[i].offset = offs;
 386			urb->iso_frame_desc[i].length = ep->curpacksize;
 387			offs += ep->curpacksize;
 388		}
 389
 390		urb->transfer_buffer_length = offs;
 391		urb->number_of_packets = urb_ctx->packets;
 392		break;
 393
 394	case SND_USB_ENDPOINT_TYPE_SYNC:
 395		urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize);
 396		urb->iso_frame_desc[0].offset = 0;
 397		break;
 398	}
 399	return 0;
 400}
 401
 402/* notify an error as XRUN to the assigned PCM data substream */
 403static void notify_xrun(struct snd_usb_endpoint *ep)
 404{
 405	struct snd_usb_substream *data_subs;
 406
 407	data_subs = READ_ONCE(ep->data_subs);
 408	if (data_subs && data_subs->pcm_substream)
 409		snd_pcm_stop_xrun(data_subs->pcm_substream);
 410}
 411
 412static struct snd_usb_packet_info *
 413next_packet_fifo_enqueue(struct snd_usb_endpoint *ep)
 414{
 415	struct snd_usb_packet_info *p;
 416
 417	p = ep->next_packet + (ep->next_packet_head + ep->next_packet_queued) %
 418		ARRAY_SIZE(ep->next_packet);
 419	ep->next_packet_queued++;
 420	return p;
 421}
 422
 423static struct snd_usb_packet_info *
 424next_packet_fifo_dequeue(struct snd_usb_endpoint *ep)
 425{
 426	struct snd_usb_packet_info *p;
 427
 428	p = ep->next_packet + ep->next_packet_head;
 429	ep->next_packet_head++;
 430	ep->next_packet_head %= ARRAY_SIZE(ep->next_packet);
 431	ep->next_packet_queued--;
 432	return p;
 433}
 434
 435static void push_back_to_ready_list(struct snd_usb_endpoint *ep,
 436				    struct snd_urb_ctx *ctx)
 437{
 438	unsigned long flags;
 439
 440	spin_lock_irqsave(&ep->lock, flags);
 441	list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
 442	spin_unlock_irqrestore(&ep->lock, flags);
 443}
 444
 445/*
 446 * Send output urbs that have been prepared previously. URBs are dequeued
 447 * from ep->ready_playback_urbs and in case there aren't any available
 448 * or there are no packets that have been prepared, this function does
 449 * nothing.
 450 *
 451 * The reason why the functionality of sending and preparing URBs is separated
 452 * is that host controllers don't guarantee the order in which they return
 453 * inbound and outbound packets to their submitters.
 454 *
 455 * This function is used both for implicit feedback endpoints and in low-
 456 * latency playback mode.
 
 457 */
 458int snd_usb_queue_pending_output_urbs(struct snd_usb_endpoint *ep,
 459				      bool in_stream_lock)
 460{
 461	bool implicit_fb = snd_usb_endpoint_implicit_feedback_sink(ep);
 462
 463	while (ep_state_running(ep)) {
 464
 465		unsigned long flags;
 466		struct snd_usb_packet_info *packet;
 467		struct snd_urb_ctx *ctx = NULL;
 
 468		int err, i;
 469
 470		spin_lock_irqsave(&ep->lock, flags);
 471		if ((!implicit_fb || ep->next_packet_queued > 0) &&
 472		    !list_empty(&ep->ready_playback_urbs)) {
 
 
 
 473			/* take URB out of FIFO */
 474			ctx = list_first_entry(&ep->ready_playback_urbs,
 
 475					       struct snd_urb_ctx, ready_list);
 476			list_del_init(&ctx->ready_list);
 477			if (implicit_fb)
 478				packet = next_packet_fifo_dequeue(ep);
 479		}
 480		spin_unlock_irqrestore(&ep->lock, flags);
 481
 482		if (ctx == NULL)
 483			break;
 
 
 
 484
 485		/* copy over the length information */
 486		if (implicit_fb) {
 487			for (i = 0; i < packet->packets; i++)
 488				ctx->packet_size[i] = packet->packet_size[i];
 489		}
 490
 491		/* call the data handler to fill in playback data */
 492		err = prepare_outbound_urb(ep, ctx, in_stream_lock);
 493		/* can be stopped during prepare callback */
 494		if (unlikely(!ep_state_running(ep)))
 495			break;
 496		if (err < 0) {
 497			/* push back to ready list again for -EAGAIN */
 498			if (err == -EAGAIN) {
 499				push_back_to_ready_list(ep, ctx);
 500				break;
 501			}
 502
 503			if (!in_stream_lock)
 504				notify_xrun(ep);
 505			return -EPIPE;
 506		}
 507
 508		if (!atomic_read(&ep->chip->shutdown))
 509			err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
 510		else
 511			err = -ENODEV;
 512		if (err < 0) {
 513			if (!atomic_read(&ep->chip->shutdown)) {
 514				usb_audio_err(ep->chip,
 515					      "Unable to submit urb #%d: %d at %s\n",
 516					      ctx->index, err, __func__);
 517				if (!in_stream_lock)
 518					notify_xrun(ep);
 519			}
 520			return -EPIPE;
 521		}
 522
 523		set_bit(ctx->index, &ep->active_mask);
 524		atomic_inc(&ep->submitted_urbs);
 525	}
 526
 527	return 0;
 528}
 529
 530/*
 531 * complete callback for urbs
 532 */
 533static void snd_complete_urb(struct urb *urb)
 534{
 535	struct snd_urb_ctx *ctx = urb->context;
 536	struct snd_usb_endpoint *ep = ctx->ep;
 
 
 537	int err;
 538
 539	if (unlikely(urb->status == -ENOENT ||		/* unlinked */
 540		     urb->status == -ENODEV ||		/* device removed */
 541		     urb->status == -ECONNRESET ||	/* unlinked */
 542		     urb->status == -ESHUTDOWN))	/* device disabled */
 543		goto exit_clear;
 544	/* device disconnected */
 545	if (unlikely(atomic_read(&ep->chip->shutdown)))
 546		goto exit_clear;
 547
 548	if (unlikely(!ep_state_running(ep)))
 549		goto exit_clear;
 550
 551	if (usb_pipeout(ep->pipe)) {
 552		retire_outbound_urb(ep, ctx);
 553		/* can be stopped during retire callback */
 554		if (unlikely(!ep_state_running(ep)))
 555			goto exit_clear;
 556
 557		/* in low-latency and implicit-feedback modes, push back the
 558		 * URB to ready list at first, then process as much as possible
 559		 */
 560		if (ep->lowlatency_playback ||
 561		     snd_usb_endpoint_implicit_feedback_sink(ep)) {
 562			push_back_to_ready_list(ep, ctx);
 563			clear_bit(ctx->index, &ep->active_mask);
 564			snd_usb_queue_pending_output_urbs(ep, false);
 565			atomic_dec(&ep->submitted_urbs); /* decrement at last */
 566			return;
 567		}
 568
 569		/* in non-lowlatency mode, no error handling for prepare */
 570		prepare_outbound_urb(ep, ctx, false);
 571		/* can be stopped during prepare callback */
 572		if (unlikely(!ep_state_running(ep)))
 573			goto exit_clear;
 
 
 
 574	} else {
 575		retire_inbound_urb(ep, ctx);
 576		/* can be stopped during retire callback */
 577		if (unlikely(!ep_state_running(ep)))
 578			goto exit_clear;
 579
 580		prepare_inbound_urb(ep, ctx);
 581	}
 582
 583	if (!atomic_read(&ep->chip->shutdown))
 584		err = usb_submit_urb(urb, GFP_ATOMIC);
 585	else
 586		err = -ENODEV;
 587	if (err == 0)
 588		return;
 589
 590	if (!atomic_read(&ep->chip->shutdown)) {
 591		usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
 592		notify_xrun(ep);
 
 593	}
 594
 595exit_clear:
 596	clear_bit(ctx->index, &ep->active_mask);
 597	atomic_dec(&ep->submitted_urbs);
 598}
 599
 600/*
 601 * Find or create a refcount object for the given interface
 602 *
 603 * The objects are released altogether in snd_usb_endpoint_free_all()
 604 */
 605static struct snd_usb_iface_ref *
 606iface_ref_find(struct snd_usb_audio *chip, int iface)
 607{
 608	struct snd_usb_iface_ref *ip;
 609
 610	list_for_each_entry(ip, &chip->iface_ref_list, list)
 611		if (ip->iface == iface)
 612			return ip;
 613
 614	ip = kzalloc(sizeof(*ip), GFP_KERNEL);
 615	if (!ip)
 616		return NULL;
 617	ip->iface = iface;
 618	list_add_tail(&ip->list, &chip->iface_ref_list);
 619	return ip;
 620}
 621
 622/* Similarly, a refcount object for clock */
 623static struct snd_usb_clock_ref *
 624clock_ref_find(struct snd_usb_audio *chip, int clock)
 625{
 626	struct snd_usb_clock_ref *ref;
 627
 628	list_for_each_entry(ref, &chip->clock_ref_list, list)
 629		if (ref->clock == clock)
 630			return ref;
 631
 632	ref = kzalloc(sizeof(*ref), GFP_KERNEL);
 633	if (!ref)
 634		return NULL;
 635	ref->clock = clock;
 636	atomic_set(&ref->locked, 0);
 637	list_add_tail(&ref->list, &chip->clock_ref_list);
 638	return ref;
 639}
 640
 641/*
 642 * Get the existing endpoint object corresponding EP
 643 * Returns NULL if not present.
 644 */
 645struct snd_usb_endpoint *
 646snd_usb_get_endpoint(struct snd_usb_audio *chip, int ep_num)
 647{
 648	struct snd_usb_endpoint *ep;
 649
 650	list_for_each_entry(ep, &chip->ep_list, list) {
 651		if (ep->ep_num == ep_num)
 652			return ep;
 653	}
 654
 655	return NULL;
 656}
 657
 658#define ep_type_name(type) \
 659	(type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync")
 660
 661/**
 662 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
 663 *
 664 * @chip: The chip
 
 665 * @ep_num: The number of the endpoint to use
 
 666 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
 667 *
 668 * If the requested endpoint has not been added to the given chip before,
 669 * a new instance is created.
 670 *
 671 * Returns zero on success or a negative error code.
 672 *
 673 * New endpoints will be added to chip->ep_list and freed by
 674 * calling snd_usb_endpoint_free_all().
 675 *
 676 * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
 677 * bNumEndpoints > 1 beforehand.
 678 */
 679int snd_usb_add_endpoint(struct snd_usb_audio *chip, int ep_num, int type)
 
 
 680{
 681	struct snd_usb_endpoint *ep;
 682	bool is_playback;
 683
 684	ep = snd_usb_get_endpoint(chip, ep_num);
 685	if (ep)
 686		return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 687
 688	usb_audio_dbg(chip, "Creating new %s endpoint #%x\n",
 689		      ep_type_name(type),
 690		      ep_num);
 691	ep = kzalloc(sizeof(*ep), GFP_KERNEL);
 692	if (!ep)
 693		return -ENOMEM;
 694
 695	ep->chip = chip;
 696	spin_lock_init(&ep->lock);
 697	ep->type = type;
 698	ep->ep_num = ep_num;
 
 
 699	INIT_LIST_HEAD(&ep->ready_playback_urbs);
 700	atomic_set(&ep->submitted_urbs, 0);
 701
 702	is_playback = ((ep_num & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT);
 703	ep_num &= USB_ENDPOINT_NUMBER_MASK;
 
 704	if (is_playback)
 705		ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
 706	else
 707		ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);
 708
 709	list_add_tail(&ep->list, &chip->ep_list);
 710	return 0;
 711}
 712
 713/* Set up syncinterval and maxsyncsize for a sync EP */
 714static void endpoint_set_syncinterval(struct snd_usb_audio *chip,
 715				      struct snd_usb_endpoint *ep)
 716{
 717	struct usb_host_interface *alts;
 718	struct usb_endpoint_descriptor *desc;
 719
 720	alts = snd_usb_get_host_interface(chip, ep->iface, ep->altsetting);
 721	if (!alts)
 722		return;
 723
 724	desc = get_endpoint(alts, ep->ep_idx);
 725	if (desc->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
 726	    desc->bRefresh >= 1 && desc->bRefresh <= 9)
 727		ep->syncinterval = desc->bRefresh;
 728	else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
 729		ep->syncinterval = 1;
 730	else if (desc->bInterval >= 1 && desc->bInterval <= 16)
 731		ep->syncinterval = desc->bInterval - 1;
 732	else
 733		ep->syncinterval = 3;
 734
 735	ep->syncmaxsize = le16_to_cpu(desc->wMaxPacketSize);
 736}
 737
 738static bool endpoint_compatible(struct snd_usb_endpoint *ep,
 739				const struct audioformat *fp,
 740				const struct snd_pcm_hw_params *params)
 741{
 742	if (!ep->opened)
 743		return false;
 744	if (ep->cur_audiofmt != fp)
 745		return false;
 746	if (ep->cur_rate != params_rate(params) ||
 747	    ep->cur_format != params_format(params) ||
 748	    ep->cur_period_frames != params_period_size(params) ||
 749	    ep->cur_buffer_periods != params_periods(params))
 750		return false;
 751	return true;
 752}
 753
 754/*
 755 * Check whether the given fp and hw params are compatible with the current
 756 * setup of the target EP for implicit feedback sync
 757 */
 758bool snd_usb_endpoint_compatible(struct snd_usb_audio *chip,
 759				 struct snd_usb_endpoint *ep,
 760				 const struct audioformat *fp,
 761				 const struct snd_pcm_hw_params *params)
 762{
 763	bool ret;
 764
 765	mutex_lock(&chip->mutex);
 766	ret = endpoint_compatible(ep, fp, params);
 767	mutex_unlock(&chip->mutex);
 768	return ret;
 769}
 770
 771/*
 772 * snd_usb_endpoint_open: Open the endpoint
 773 *
 774 * Called from hw_params to assign the endpoint to the substream.
 775 * It's reference-counted, and only the first opener is allowed to set up
 776 * arbitrary parameters.  The later opener must be compatible with the
 777 * former opened parameters.
 778 * The endpoint needs to be closed via snd_usb_endpoint_close() later.
 779 *
 780 * Note that this function doesn't configure the endpoint.  The substream
 781 * needs to set it up later via snd_usb_endpoint_set_params() and
 782 * snd_usb_endpoint_prepare().
 783 */
 784struct snd_usb_endpoint *
 785snd_usb_endpoint_open(struct snd_usb_audio *chip,
 786		      const struct audioformat *fp,
 787		      const struct snd_pcm_hw_params *params,
 788		      bool is_sync_ep,
 789		      bool fixed_rate)
 790{
 791	struct snd_usb_endpoint *ep;
 792	int ep_num = is_sync_ep ? fp->sync_ep : fp->endpoint;
 793
 794	mutex_lock(&chip->mutex);
 795	ep = snd_usb_get_endpoint(chip, ep_num);
 796	if (!ep) {
 797		usb_audio_err(chip, "Cannot find EP 0x%x to open\n", ep_num);
 798		goto unlock;
 799	}
 800
 801	if (!ep->opened) {
 802		if (is_sync_ep) {
 803			ep->iface = fp->sync_iface;
 804			ep->altsetting = fp->sync_altsetting;
 805			ep->ep_idx = fp->sync_ep_idx;
 806		} else {
 807			ep->iface = fp->iface;
 808			ep->altsetting = fp->altsetting;
 809			ep->ep_idx = fp->ep_idx;
 810		}
 811		usb_audio_dbg(chip, "Open EP 0x%x, iface=%d:%d, idx=%d\n",
 812			      ep_num, ep->iface, ep->altsetting, ep->ep_idx);
 813
 814		ep->iface_ref = iface_ref_find(chip, ep->iface);
 815		if (!ep->iface_ref) {
 816			ep = NULL;
 817			goto unlock;
 818		}
 819
 820		if (fp->protocol != UAC_VERSION_1) {
 821			ep->clock_ref = clock_ref_find(chip, fp->clock);
 822			if (!ep->clock_ref) {
 823				ep = NULL;
 824				goto unlock;
 825			}
 826			ep->clock_ref->opened++;
 827		}
 828
 829		ep->cur_audiofmt = fp;
 830		ep->cur_channels = fp->channels;
 831		ep->cur_rate = params_rate(params);
 832		ep->cur_format = params_format(params);
 833		ep->cur_frame_bytes = snd_pcm_format_physical_width(ep->cur_format) *
 834			ep->cur_channels / 8;
 835		ep->cur_period_frames = params_period_size(params);
 836		ep->cur_period_bytes = ep->cur_period_frames * ep->cur_frame_bytes;
 837		ep->cur_buffer_periods = params_periods(params);
 838
 839		if (ep->type == SND_USB_ENDPOINT_TYPE_SYNC)
 840			endpoint_set_syncinterval(chip, ep);
 841
 842		ep->implicit_fb_sync = fp->implicit_fb;
 843		ep->need_setup = true;
 844		ep->need_prepare = true;
 845		ep->fixed_rate = fixed_rate;
 846
 847		usb_audio_dbg(chip, "  channels=%d, rate=%d, format=%s, period_bytes=%d, periods=%d, implicit_fb=%d\n",
 848			      ep->cur_channels, ep->cur_rate,
 849			      snd_pcm_format_name(ep->cur_format),
 850			      ep->cur_period_bytes, ep->cur_buffer_periods,
 851			      ep->implicit_fb_sync);
 852
 853	} else {
 854		if (WARN_ON(!ep->iface_ref)) {
 855			ep = NULL;
 856			goto unlock;
 857		}
 858
 859		if (!endpoint_compatible(ep, fp, params)) {
 860			usb_audio_err(chip, "Incompatible EP setup for 0x%x\n",
 861				      ep_num);
 862			ep = NULL;
 863			goto unlock;
 864		}
 865
 866		usb_audio_dbg(chip, "Reopened EP 0x%x (count %d)\n",
 867			      ep_num, ep->opened);
 868	}
 869
 870	if (!ep->iface_ref->opened++)
 871		ep->iface_ref->need_setup = true;
 872
 873	ep->opened++;
 874
 875 unlock:
 876	mutex_unlock(&chip->mutex);
 877	return ep;
 878}
 879
 880/*
 881 * snd_usb_endpoint_set_sync: Link data and sync endpoints
 882 *
 883 * Pass NULL to sync_ep to unlink again
 884 */
 885void snd_usb_endpoint_set_sync(struct snd_usb_audio *chip,
 886			       struct snd_usb_endpoint *data_ep,
 887			       struct snd_usb_endpoint *sync_ep)
 888{
 889	data_ep->sync_source = sync_ep;
 890}
 891
 892/*
 893 * Set data endpoint callbacks and the assigned data stream
 894 *
 895 * Called at PCM trigger and cleanups.
 896 * Pass NULL to deactivate each callback.
 897 */
 898void snd_usb_endpoint_set_callback(struct snd_usb_endpoint *ep,
 899				   int (*prepare)(struct snd_usb_substream *subs,
 900						  struct urb *urb,
 901						  bool in_stream_lock),
 902				   void (*retire)(struct snd_usb_substream *subs,
 903						  struct urb *urb),
 904				   struct snd_usb_substream *data_subs)
 905{
 906	ep->prepare_data_urb = prepare;
 907	ep->retire_data_urb = retire;
 908	if (data_subs)
 909		ep->lowlatency_playback = data_subs->lowlatency_playback;
 910	else
 911		ep->lowlatency_playback = false;
 912	WRITE_ONCE(ep->data_subs, data_subs);
 913}
 914
 915static int endpoint_set_interface(struct snd_usb_audio *chip,
 916				  struct snd_usb_endpoint *ep,
 917				  bool set)
 918{
 919	int altset = set ? ep->altsetting : 0;
 920	int err;
 921
 922	if (ep->iface_ref->altset == altset)
 923		return 0;
 924
 925	usb_audio_dbg(chip, "Setting usb interface %d:%d for EP 0x%x\n",
 926		      ep->iface, altset, ep->ep_num);
 927	err = usb_set_interface(chip->dev, ep->iface, altset);
 928	if (err < 0) {
 929		usb_audio_err_ratelimited(
 930			chip, "%d:%d: usb_set_interface failed (%d)\n",
 931			ep->iface, altset, err);
 932		return err;
 933	}
 934
 935	if (chip->quirk_flags & QUIRK_FLAG_IFACE_DELAY)
 936		msleep(50);
 937	ep->iface_ref->altset = altset;
 938	return 0;
 939}
 940
 941/*
 942 * snd_usb_endpoint_close: Close the endpoint
 943 *
 944 * Unreference the already opened endpoint via snd_usb_endpoint_open().
 945 */
 946void snd_usb_endpoint_close(struct snd_usb_audio *chip,
 947			    struct snd_usb_endpoint *ep)
 948{
 949	mutex_lock(&chip->mutex);
 950	usb_audio_dbg(chip, "Closing EP 0x%x (count %d)\n",
 951		      ep->ep_num, ep->opened);
 952
 953	if (!--ep->iface_ref->opened &&
 954		!(chip->quirk_flags & QUIRK_FLAG_IFACE_SKIP_CLOSE))
 955		endpoint_set_interface(chip, ep, false);
 956
 957	if (!--ep->opened) {
 958		if (ep->clock_ref) {
 959			if (!--ep->clock_ref->opened)
 960				ep->clock_ref->rate = 0;
 961		}
 962		ep->iface = 0;
 963		ep->altsetting = 0;
 964		ep->cur_audiofmt = NULL;
 965		ep->cur_rate = 0;
 966		ep->iface_ref = NULL;
 967		ep->clock_ref = NULL;
 968		usb_audio_dbg(chip, "EP 0x%x closed\n", ep->ep_num);
 969	}
 970	mutex_unlock(&chip->mutex);
 971}
 972
 973/* Prepare for suspening EP, called from the main suspend handler */
 974void snd_usb_endpoint_suspend(struct snd_usb_endpoint *ep)
 975{
 976	ep->need_prepare = true;
 977	if (ep->iface_ref)
 978		ep->iface_ref->need_setup = true;
 979	if (ep->clock_ref)
 980		ep->clock_ref->rate = 0;
 981}
 982
 983/*
 984 *  wait until all urbs are processed.
 985 */
 986static int wait_clear_urbs(struct snd_usb_endpoint *ep)
 987{
 988	unsigned long end_time = jiffies + msecs_to_jiffies(1000);
 989	int alive;
 990
 991	if (atomic_read(&ep->state) != EP_STATE_STOPPING)
 992		return 0;
 993
 994	do {
 995		alive = atomic_read(&ep->submitted_urbs);
 996		if (!alive)
 997			break;
 998
 999		schedule_timeout_uninterruptible(1);
1000	} while (time_before(jiffies, end_time));
1001
1002	if (alive)
1003		usb_audio_err(ep->chip,
1004			"timeout: still %d active urbs on EP #%x\n",
1005			alive, ep->ep_num);
 
1006
1007	if (ep_state_update(ep, EP_STATE_STOPPING, EP_STATE_STOPPED)) {
1008		ep->sync_sink = NULL;
1009		snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
1010	}
1011
1012	return 0;
1013}
1014
1015/* sync the pending stop operation;
1016 * this function itself doesn't trigger the stop operation
1017 */
1018void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
1019{
1020	if (ep)
1021		wait_clear_urbs(ep);
1022}
1023
1024/*
1025 * Stop active urbs
1026 *
1027 * This function moves the EP to STOPPING state if it's being RUNNING.
1028 */
1029static int stop_urbs(struct snd_usb_endpoint *ep, bool force, bool keep_pending)
1030{
1031	unsigned int i;
1032	unsigned long flags;
1033
1034	if (!force && atomic_read(&ep->running))
1035		return -EBUSY;
1036
1037	if (!ep_state_update(ep, EP_STATE_RUNNING, EP_STATE_STOPPING))
1038		return 0;
1039
1040	spin_lock_irqsave(&ep->lock, flags);
1041	INIT_LIST_HEAD(&ep->ready_playback_urbs);
1042	ep->next_packet_head = 0;
1043	ep->next_packet_queued = 0;
1044	spin_unlock_irqrestore(&ep->lock, flags);
1045
1046	if (keep_pending)
1047		return 0;
1048
1049	for (i = 0; i < ep->nurbs; i++) {
1050		if (test_bit(i, &ep->active_mask)) {
1051			if (!test_and_set_bit(i, &ep->unlink_mask)) {
1052				struct urb *u = ep->urb[i].urb;
1053				usb_unlink_urb(u);
1054			}
1055		}
1056	}
1057
1058	return 0;
1059}
1060
1061/*
1062 * release an endpoint's urbs
1063 */
1064static int release_urbs(struct snd_usb_endpoint *ep, bool force)
1065{
1066	int i, err;
1067
1068	/* route incoming urbs to nirvana */
1069	snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
1070
1071	/* stop and unlink urbs */
1072	err = stop_urbs(ep, force, false);
1073	if (err)
1074		return err;
1075
 
 
1076	wait_clear_urbs(ep);
1077
1078	for (i = 0; i < ep->nurbs; i++)
1079		release_urb_ctx(&ep->urb[i]);
1080
1081	usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
1082			  ep->syncbuf, ep->sync_dma);
 
1083
1084	ep->syncbuf = NULL;
1085	ep->nurbs = 0;
1086	return 0;
1087}
1088
1089/*
1090 * configure a data endpoint
1091 */
1092static int data_ep_set_params(struct snd_usb_endpoint *ep)
 
 
 
 
 
 
 
1093{
1094	struct snd_usb_audio *chip = ep->chip;
1095	unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
1096	unsigned int max_packs_per_period, urbs_per_period, urb_packs;
1097	unsigned int max_urbs, i;
1098	const struct audioformat *fmt = ep->cur_audiofmt;
1099	int frame_bits = ep->cur_frame_bytes * 8;
1100	int tx_length_quirk = (has_tx_length_quirk(chip) &&
1101			       usb_pipeout(ep->pipe));
1102
1103	usb_audio_dbg(chip, "Setting params for data EP 0x%x, pipe 0x%x\n",
1104		      ep->ep_num, ep->pipe);
1105
1106	if (ep->cur_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
1107		/*
1108		 * When operating in DSD DOP mode, the size of a sample frame
1109		 * in hardware differs from the actual physical format width
1110		 * because we need to make room for the DOP markers.
1111		 */
1112		frame_bits += ep->cur_channels << 3;
1113	}
1114
1115	ep->datainterval = fmt->datainterval;
1116	ep->stride = frame_bits >> 3;
1117
1118	switch (ep->cur_format) {
1119	case SNDRV_PCM_FORMAT_U8:
1120		ep->silence_value = 0x80;
1121		break;
1122	case SNDRV_PCM_FORMAT_DSD_U8:
1123	case SNDRV_PCM_FORMAT_DSD_U16_LE:
1124	case SNDRV_PCM_FORMAT_DSD_U32_LE:
1125	case SNDRV_PCM_FORMAT_DSD_U16_BE:
1126	case SNDRV_PCM_FORMAT_DSD_U32_BE:
1127		ep->silence_value = 0x69;
1128		break;
1129	default:
1130		ep->silence_value = 0;
1131	}
1132
1133	/* assume max. frequency is 50% higher than nominal */
1134	ep->freqmax = ep->freqn + (ep->freqn >> 1);
1135	/* Round up freqmax to nearest integer in order to calculate maximum
1136	 * packet size, which must represent a whole number of frames.
1137	 * This is accomplished by adding 0x0.ffff before converting the
1138	 * Q16.16 format into integer.
1139	 * In order to accurately calculate the maximum packet size when
1140	 * the data interval is more than 1 (i.e. ep->datainterval > 0),
1141	 * multiply by the data interval prior to rounding. For instance,
1142	 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
1143	 * frames with a data interval of 1, but 11 (10.25) frames with a
1144	 * data interval of 2.
1145	 * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
1146	 * maximum datainterval value of 3, at USB full speed, higher for
1147	 * USB high speed, noting that ep->freqmax is in units of
1148	 * frames per packet in Q16.16 format.)
1149	 */
1150	maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
1151			 (frame_bits >> 3);
1152	if (tx_length_quirk)
1153		maxsize += sizeof(__le32); /* Space for length descriptor */
1154	/* but wMaxPacketSize might reduce this */
1155	if (ep->maxpacksize && ep->maxpacksize < maxsize) {
1156		/* whatever fits into a max. size packet */
1157		unsigned int data_maxsize = maxsize = ep->maxpacksize;
1158
1159		if (tx_length_quirk)
1160			/* Need to remove the length descriptor to calc freq */
1161			data_maxsize -= sizeof(__le32);
1162		ep->freqmax = (data_maxsize / (frame_bits >> 3))
1163				<< (16 - ep->datainterval);
1164	}
1165
1166	if (ep->fill_max)
1167		ep->curpacksize = ep->maxpacksize;
1168	else
1169		ep->curpacksize = maxsize;
1170
1171	if (snd_usb_get_speed(chip->dev) != USB_SPEED_FULL) {
1172		packs_per_ms = 8 >> ep->datainterval;
1173		max_packs_per_urb = MAX_PACKS_HS;
1174	} else {
1175		packs_per_ms = 1;
1176		max_packs_per_urb = MAX_PACKS;
1177	}
1178	if (ep->sync_source && !ep->implicit_fb_sync)
1179		max_packs_per_urb = min(max_packs_per_urb,
1180					1U << ep->sync_source->syncinterval);
1181	max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);
1182
1183	/*
1184	 * Capture endpoints need to use small URBs because there's no way
1185	 * to tell in advance where the next period will end, and we don't
1186	 * want the next URB to complete much after the period ends.
1187	 *
1188	 * Playback endpoints with implicit sync much use the same parameters
1189	 * as their corresponding capture endpoint.
1190	 */
1191	if (usb_pipein(ep->pipe) || ep->implicit_fb_sync) {
 
1192
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1193		/* make capture URBs <= 1 ms and smaller than a period */
1194		urb_packs = min(max_packs_per_urb, packs_per_ms);
1195		while (urb_packs > 1 && urb_packs * maxsize >= ep->cur_period_bytes)
1196			urb_packs >>= 1;
1197		ep->nurbs = MAX_URBS;
1198
1199	/*
1200	 * Playback endpoints without implicit sync are adjusted so that
1201	 * a period fits as evenly as possible in the smallest number of
1202	 * URBs.  The total number of URBs is adjusted to the size of the
1203	 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
1204	 */
1205	} else {
1206		/* determine how small a packet can be */
1207		minsize = (ep->freqn >> (16 - ep->datainterval)) *
1208				(frame_bits >> 3);
1209		/* with sync from device, assume it can be 12% lower */
1210		if (ep->sync_source)
1211			minsize -= minsize >> 3;
1212		minsize = max(minsize, 1u);
1213
1214		/* how many packets will contain an entire ALSA period? */
1215		max_packs_per_period = DIV_ROUND_UP(ep->cur_period_bytes, minsize);
1216
1217		/* how many URBs will contain a period? */
1218		urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
1219				max_packs_per_urb);
1220		/* how many packets are needed in each URB? */
1221		urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);
1222
1223		/* limit the number of frames in a single URB */
1224		ep->max_urb_frames = DIV_ROUND_UP(ep->cur_period_frames,
1225						  urbs_per_period);
1226
1227		/* try to use enough URBs to contain an entire ALSA buffer */
1228		max_urbs = min((unsigned) MAX_URBS,
1229				MAX_QUEUE * packs_per_ms / urb_packs);
1230		ep->nurbs = min(max_urbs, urbs_per_period * ep->cur_buffer_periods);
1231	}
1232
1233	/* allocate and initialize data urbs */
1234	for (i = 0; i < ep->nurbs; i++) {
1235		struct snd_urb_ctx *u = &ep->urb[i];
1236		u->index = i;
1237		u->ep = ep;
1238		u->packets = urb_packs;
1239		u->buffer_size = maxsize * u->packets;
1240
1241		if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
1242			u->packets++; /* for transfer delimiter */
1243		u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
1244		if (!u->urb)
1245			goto out_of_memory;
1246
1247		u->urb->transfer_buffer =
1248			usb_alloc_coherent(chip->dev, u->buffer_size,
1249					   GFP_KERNEL, &u->urb->transfer_dma);
1250		if (!u->urb->transfer_buffer)
1251			goto out_of_memory;
1252		u->urb->pipe = ep->pipe;
1253		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
1254		u->urb->interval = 1 << ep->datainterval;
1255		u->urb->context = u;
1256		u->urb->complete = snd_complete_urb;
1257		INIT_LIST_HEAD(&u->ready_list);
1258	}
1259
1260	return 0;
1261
1262out_of_memory:
1263	release_urbs(ep, false);
1264	return -ENOMEM;
1265}
1266
1267/*
1268 * configure a sync endpoint
1269 */
1270static int sync_ep_set_params(struct snd_usb_endpoint *ep)
1271{
1272	struct snd_usb_audio *chip = ep->chip;
1273	int i;
1274
1275	usb_audio_dbg(chip, "Setting params for sync EP 0x%x, pipe 0x%x\n",
1276		      ep->ep_num, ep->pipe);
1277
1278	ep->syncbuf = usb_alloc_coherent(chip->dev, SYNC_URBS * 4,
1279					 GFP_KERNEL, &ep->sync_dma);
1280	if (!ep->syncbuf)
1281		return -ENOMEM;
1282
1283	ep->nurbs = SYNC_URBS;
1284	for (i = 0; i < SYNC_URBS; i++) {
1285		struct snd_urb_ctx *u = &ep->urb[i];
1286		u->index = i;
1287		u->ep = ep;
1288		u->packets = 1;
1289		u->urb = usb_alloc_urb(1, GFP_KERNEL);
1290		if (!u->urb)
1291			goto out_of_memory;
1292		u->urb->transfer_buffer = ep->syncbuf + i * 4;
1293		u->urb->transfer_dma = ep->sync_dma + i * 4;
1294		u->urb->transfer_buffer_length = 4;
1295		u->urb->pipe = ep->pipe;
1296		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
1297		u->urb->number_of_packets = 1;
1298		u->urb->interval = 1 << ep->syncinterval;
1299		u->urb->context = u;
1300		u->urb->complete = snd_complete_urb;
1301	}
1302
 
 
1303	return 0;
1304
1305out_of_memory:
1306	release_urbs(ep, false);
1307	return -ENOMEM;
1308}
1309
1310/* update the rate of the referred clock; return the actual rate */
1311static int update_clock_ref_rate(struct snd_usb_audio *chip,
1312				 struct snd_usb_endpoint *ep)
1313{
1314	struct snd_usb_clock_ref *clock = ep->clock_ref;
1315	int rate = ep->cur_rate;
1316
1317	if (!clock || clock->rate == rate)
1318		return rate;
1319	if (clock->rate) {
1320		if (atomic_read(&clock->locked))
1321			return clock->rate;
1322		if (clock->rate != rate) {
1323			usb_audio_err(chip, "Mismatched sample rate %d vs %d for EP 0x%x\n",
1324				      clock->rate, rate, ep->ep_num);
1325			return clock->rate;
1326		}
1327	}
1328	clock->rate = rate;
1329	clock->need_setup = true;
1330	return rate;
1331}
1332
1333/*
1334 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
1335 *
1336 * It's called either from hw_params callback.
 
 
 
 
 
 
 
 
 
1337 * Determine the number of URBs to be used on this endpoint.
1338 * An endpoint must be configured before it can be started.
1339 * An endpoint that is already running can not be reconfigured.
1340 */
1341int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
1342				struct snd_usb_endpoint *ep)
 
 
 
 
 
 
 
1343{
1344	const struct audioformat *fmt = ep->cur_audiofmt;
1345	int err = 0;
1346
1347	mutex_lock(&chip->mutex);
1348	if (!ep->need_setup)
1349		goto unlock;
 
 
 
1350
1351	/* release old buffers, if any */
1352	err = release_urbs(ep, false);
1353	if (err < 0)
1354		goto unlock;
1355
1356	ep->datainterval = fmt->datainterval;
1357	ep->maxpacksize = fmt->maxpacksize;
1358	ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
1359
1360	if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL) {
1361		ep->freqn = get_usb_full_speed_rate(ep->cur_rate);
1362		ep->pps = 1000 >> ep->datainterval;
1363	} else {
1364		ep->freqn = get_usb_high_speed_rate(ep->cur_rate);
1365		ep->pps = 8000 >> ep->datainterval;
1366	}
1367
1368	ep->sample_rem = ep->cur_rate % ep->pps;
1369	ep->packsize[0] = ep->cur_rate / ep->pps;
1370	ep->packsize[1] = (ep->cur_rate + (ep->pps - 1)) / ep->pps;
1371
1372	/* calculate the frequency in 16.16 format */
1373	ep->freqm = ep->freqn;
1374	ep->freqshift = INT_MIN;
1375
1376	ep->phase = 0;
1377
1378	switch (ep->type) {
1379	case  SND_USB_ENDPOINT_TYPE_DATA:
1380		err = data_ep_set_params(ep);
 
 
1381		break;
1382	case  SND_USB_ENDPOINT_TYPE_SYNC:
1383		err = sync_ep_set_params(ep);
1384		break;
1385	default:
1386		err = -EINVAL;
1387	}
1388
1389	usb_audio_dbg(chip, "Set up %d URBS, ret=%d\n", ep->nurbs, err);
1390
1391	if (err < 0)
1392		goto unlock;
1393
1394	/* some unit conversions in runtime */
1395	ep->maxframesize = ep->maxpacksize / ep->cur_frame_bytes;
1396	ep->curframesize = ep->curpacksize / ep->cur_frame_bytes;
1397
1398	err = update_clock_ref_rate(chip, ep);
1399	if (err >= 0) {
1400		ep->need_setup = false;
1401		err = 0;
1402	}
1403
1404 unlock:
1405	mutex_unlock(&chip->mutex);
1406	return err;
1407}
1408
1409static int init_sample_rate(struct snd_usb_audio *chip,
1410			    struct snd_usb_endpoint *ep)
1411{
1412	struct snd_usb_clock_ref *clock = ep->clock_ref;
1413	int rate, err;
1414
1415	rate = update_clock_ref_rate(chip, ep);
1416	if (rate < 0)
1417		return rate;
1418	if (clock && !clock->need_setup)
1419		return 0;
1420
1421	if (!ep->fixed_rate) {
1422		err = snd_usb_init_sample_rate(chip, ep->cur_audiofmt, rate);
1423		if (err < 0) {
1424			if (clock)
1425				clock->rate = 0; /* reset rate */
1426			return err;
1427		}
1428	}
1429
1430	if (clock)
1431		clock->need_setup = false;
1432	return 0;
1433}
1434
1435/*
1436 * snd_usb_endpoint_prepare: Prepare the endpoint
1437 *
1438 * This function sets up the EP to be fully usable state.
1439 * It's called either from prepare callback.
1440 * The function checks need_setup flag, and performs nothing unless needed,
1441 * so it's safe to call this multiple times.
1442 *
1443 * This returns zero if unchanged, 1 if the configuration has changed,
1444 * or a negative error code.
1445 */
1446int snd_usb_endpoint_prepare(struct snd_usb_audio *chip,
1447			     struct snd_usb_endpoint *ep)
1448{
1449	bool iface_first;
1450	int err = 0;
1451
1452	mutex_lock(&chip->mutex);
1453	if (WARN_ON(!ep->iface_ref))
1454		goto unlock;
1455	if (!ep->need_prepare)
1456		goto unlock;
1457
1458	/* If the interface has been already set up, just set EP parameters */
1459	if (!ep->iface_ref->need_setup) {
1460		/* sample rate setup of UAC1 is per endpoint, and we need
1461		 * to update at each EP configuration
1462		 */
1463		if (ep->cur_audiofmt->protocol == UAC_VERSION_1) {
1464			err = init_sample_rate(chip, ep);
1465			if (err < 0)
1466				goto unlock;
1467		}
1468		goto done;
1469	}
1470
1471	/* Need to deselect altsetting at first */
1472	endpoint_set_interface(chip, ep, false);
1473
1474	/* Some UAC1 devices (e.g. Yamaha THR10) need the host interface
1475	 * to be set up before parameter setups
1476	 */
1477	iface_first = ep->cur_audiofmt->protocol == UAC_VERSION_1;
1478	/* Workaround for devices that require the interface setup at first like UAC1 */
1479	if (chip->quirk_flags & QUIRK_FLAG_SET_IFACE_FIRST)
1480		iface_first = true;
1481	if (iface_first) {
1482		err = endpoint_set_interface(chip, ep, true);
1483		if (err < 0)
1484			goto unlock;
1485	}
1486
1487	err = snd_usb_init_pitch(chip, ep->cur_audiofmt);
1488	if (err < 0)
1489		goto unlock;
1490
1491	err = init_sample_rate(chip, ep);
1492	if (err < 0)
1493		goto unlock;
1494
1495	err = snd_usb_select_mode_quirk(chip, ep->cur_audiofmt);
1496	if (err < 0)
1497		goto unlock;
1498
1499	/* for UAC2/3, enable the interface altset here at last */
1500	if (!iface_first) {
1501		err = endpoint_set_interface(chip, ep, true);
1502		if (err < 0)
1503			goto unlock;
1504	}
1505
1506	ep->iface_ref->need_setup = false;
1507
1508 done:
1509	ep->need_prepare = false;
1510	err = 1;
1511
1512unlock:
1513	mutex_unlock(&chip->mutex);
1514	return err;
1515}
1516
1517/* get the current rate set to the given clock by any endpoint */
1518int snd_usb_endpoint_get_clock_rate(struct snd_usb_audio *chip, int clock)
1519{
1520	struct snd_usb_clock_ref *ref;
1521	int rate = 0;
1522
1523	if (!clock)
1524		return 0;
1525	mutex_lock(&chip->mutex);
1526	list_for_each_entry(ref, &chip->clock_ref_list, list) {
1527		if (ref->clock == clock) {
1528			rate = ref->rate;
1529			break;
1530		}
1531	}
1532	mutex_unlock(&chip->mutex);
1533	return rate;
1534}
1535
1536/**
1537 * snd_usb_endpoint_start: start an snd_usb_endpoint
1538 *
1539 * @ep: the endpoint to start
1540 *
1541 * A call to this function will increment the running count of the endpoint.
1542 * In case it is not already running, the URBs for this endpoint will be
1543 * submitted. Otherwise, this function does nothing.
1544 *
1545 * Must be balanced to calls of snd_usb_endpoint_stop().
1546 *
1547 * Returns an error if the URB submission failed, 0 in all other cases.
1548 */
1549int snd_usb_endpoint_start(struct snd_usb_endpoint *ep)
1550{
1551	bool is_playback = usb_pipeout(ep->pipe);
1552	int err;
1553	unsigned int i;
1554
1555	if (atomic_read(&ep->chip->shutdown))
1556		return -EBADFD;
1557
1558	if (ep->sync_source)
1559		WRITE_ONCE(ep->sync_source->sync_sink, ep);
1560
1561	usb_audio_dbg(ep->chip, "Starting %s EP 0x%x (running %d)\n",
1562		      ep_type_name(ep->type), ep->ep_num,
1563		      atomic_read(&ep->running));
1564
1565	/* already running? */
1566	if (atomic_inc_return(&ep->running) != 1)
1567		return 0;
1568
1569	if (ep->clock_ref)
1570		atomic_inc(&ep->clock_ref->locked);
1571
1572	ep->active_mask = 0;
1573	ep->unlink_mask = 0;
1574	ep->phase = 0;
1575	ep->sample_accum = 0;
1576
1577	snd_usb_endpoint_start_quirk(ep);
1578
1579	/*
1580	 * If this endpoint has a data endpoint as implicit feedback source,
1581	 * don't start the urbs here. Instead, mark them all as available,
1582	 * wait for the record urbs to return and queue the playback urbs
1583	 * from that context.
1584	 */
1585
1586	if (!ep_state_update(ep, EP_STATE_STOPPED, EP_STATE_RUNNING))
1587		goto __error;
1588
1589	if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1590	    !(ep->chip->quirk_flags & QUIRK_FLAG_PLAYBACK_FIRST)) {
1591		usb_audio_dbg(ep->chip, "No URB submission due to implicit fb sync\n");
1592		i = 0;
1593		goto fill_rest;
 
 
1594	}
1595
1596	for (i = 0; i < ep->nurbs; i++) {
1597		struct urb *urb = ep->urb[i].urb;
1598
1599		if (snd_BUG_ON(!urb))
1600			goto __error;
1601
1602		if (is_playback)
1603			err = prepare_outbound_urb(ep, urb->context, true);
1604		else
1605			err = prepare_inbound_urb(ep, urb->context);
1606		if (err < 0) {
1607			/* stop filling at applptr */
1608			if (err == -EAGAIN)
1609				break;
1610			usb_audio_dbg(ep->chip,
1611				      "EP 0x%x: failed to prepare urb: %d\n",
1612				      ep->ep_num, err);
1613			goto __error;
1614		}
1615
1616		if (!atomic_read(&ep->chip->shutdown))
1617			err = usb_submit_urb(urb, GFP_ATOMIC);
1618		else
1619			err = -ENODEV;
1620		if (err < 0) {
1621			if (!atomic_read(&ep->chip->shutdown))
1622				usb_audio_err(ep->chip,
1623					      "cannot submit urb %d, error %d: %s\n",
1624					      i, err, usb_error_string(err));
1625			goto __error;
1626		}
1627		set_bit(i, &ep->active_mask);
1628		atomic_inc(&ep->submitted_urbs);
1629	}
1630
1631	if (!i) {
1632		usb_audio_dbg(ep->chip, "XRUN at starting EP 0x%x\n",
1633			      ep->ep_num);
1634		goto __error;
1635	}
1636
1637	usb_audio_dbg(ep->chip, "%d URBs submitted for EP 0x%x\n",
1638		      i, ep->ep_num);
1639
1640 fill_rest:
1641	/* put the remaining URBs to ready list */
1642	if (is_playback) {
1643		for (; i < ep->nurbs; i++)
1644			push_back_to_ready_list(ep, ep->urb + i);
1645	}
1646
1647	return 0;
1648
1649__error:
1650	snd_usb_endpoint_stop(ep, false);
 
 
1651	return -EPIPE;
1652}
1653
1654/**
1655 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
1656 *
1657 * @ep: the endpoint to stop (may be NULL)
1658 * @keep_pending: keep in-flight URBs
1659 *
1660 * A call to this function will decrement the running count of the endpoint.
1661 * In case the last user has requested the endpoint stop, the URBs will
1662 * actually be deactivated.
1663 *
1664 * Must be balanced to calls of snd_usb_endpoint_start().
1665 *
1666 * The caller needs to synchronize the pending stop operation via
1667 * snd_usb_endpoint_sync_pending_stop().
1668 */
1669void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep, bool keep_pending)
1670{
1671	if (!ep)
1672		return;
1673
1674	usb_audio_dbg(ep->chip, "Stopping %s EP 0x%x (running %d)\n",
1675		      ep_type_name(ep->type), ep->ep_num,
1676		      atomic_read(&ep->running));
1677
1678	if (snd_BUG_ON(!atomic_read(&ep->running)))
1679		return;
1680
1681	if (!atomic_dec_return(&ep->running)) {
1682		if (ep->sync_source)
1683			WRITE_ONCE(ep->sync_source->sync_sink, NULL);
1684		stop_urbs(ep, false, keep_pending);
1685		if (ep->clock_ref)
1686			atomic_dec(&ep->clock_ref->locked);
1687
1688		if (ep->chip->quirk_flags & QUIRK_FLAG_FORCE_IFACE_RESET &&
1689		    usb_pipeout(ep->pipe)) {
1690			ep->need_prepare = true;
1691			if (ep->iface_ref)
1692				ep->iface_ref->need_setup = true;
1693		}
1694	}
1695}
1696
1697/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1698 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
1699 *
1700 * @ep: the endpoint to release
1701 *
1702 * This function does not care for the endpoint's running count but will tear
1703 * down all the streaming URBs immediately.
1704 */
1705void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
1706{
1707	release_urbs(ep, true);
1708}
1709
1710/**
1711 * snd_usb_endpoint_free_all: Free the resources of an snd_usb_endpoint
1712 * @chip: The chip
1713 *
1714 * This free all endpoints and those resources
 
 
1715 */
1716void snd_usb_endpoint_free_all(struct snd_usb_audio *chip)
1717{
1718	struct snd_usb_endpoint *ep, *en;
1719	struct snd_usb_iface_ref *ip, *in;
1720	struct snd_usb_clock_ref *cp, *cn;
1721
1722	list_for_each_entry_safe(ep, en, &chip->ep_list, list)
1723		kfree(ep);
1724
1725	list_for_each_entry_safe(ip, in, &chip->iface_ref_list, list)
1726		kfree(ip);
1727
1728	list_for_each_entry_safe(cp, cn, &chip->clock_ref_list, list)
1729		kfree(cp);
1730}
1731
1732/*
1733 * snd_usb_handle_sync_urb: parse an USB sync packet
1734 *
1735 * @ep: the endpoint to handle the packet
1736 * @sender: the sending endpoint
1737 * @urb: the received packet
1738 *
1739 * This function is called from the context of an endpoint that received
1740 * the packet and is used to let another endpoint object handle the payload.
1741 */
1742static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
1743				    struct snd_usb_endpoint *sender,
1744				    const struct urb *urb)
1745{
1746	int shift;
1747	unsigned int f;
1748	unsigned long flags;
1749
1750	snd_BUG_ON(ep == sender);
1751
1752	/*
1753	 * In case the endpoint is operating in implicit feedback mode, prepare
1754	 * a new outbound URB that has the same layout as the received packet
1755	 * and add it to the list of pending urbs. queue_pending_output_urbs()
1756	 * will take care of them later.
1757	 */
1758	if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1759	    atomic_read(&ep->running)) {
1760
1761		/* implicit feedback case */
1762		int i, bytes = 0;
1763		struct snd_urb_ctx *in_ctx;
1764		struct snd_usb_packet_info *out_packet;
1765
1766		in_ctx = urb->context;
1767
1768		/* Count overall packet size */
1769		for (i = 0; i < in_ctx->packets; i++)
1770			if (urb->iso_frame_desc[i].status == 0)
1771				bytes += urb->iso_frame_desc[i].actual_length;
1772
1773		/*
1774		 * skip empty packets. At least M-Audio's Fast Track Ultra stops
1775		 * streaming once it received a 0-byte OUT URB
1776		 */
1777		if (bytes == 0)
1778			return;
1779
1780		spin_lock_irqsave(&ep->lock, flags);
1781		if (ep->next_packet_queued >= ARRAY_SIZE(ep->next_packet)) {
1782			spin_unlock_irqrestore(&ep->lock, flags);
1783			usb_audio_err(ep->chip,
1784				      "next package FIFO overflow EP 0x%x\n",
1785				      ep->ep_num);
1786			notify_xrun(ep);
1787			return;
1788		}
1789
1790		out_packet = next_packet_fifo_enqueue(ep);
1791
1792		/*
1793		 * Iterate through the inbound packet and prepare the lengths
1794		 * for the output packet. The OUT packet we are about to send
1795		 * will have the same amount of payload bytes per stride as the
1796		 * IN packet we just received. Since the actual size is scaled
1797		 * by the stride, use the sender stride to calculate the length
1798		 * in case the number of channels differ between the implicitly
1799		 * fed-back endpoint and the synchronizing endpoint.
1800		 */
1801
1802		out_packet->packets = in_ctx->packets;
1803		for (i = 0; i < in_ctx->packets; i++) {
1804			if (urb->iso_frame_desc[i].status == 0)
1805				out_packet->packet_size[i] =
1806					urb->iso_frame_desc[i].actual_length / sender->stride;
1807			else
1808				out_packet->packet_size[i] = 0;
1809		}
1810
 
 
1811		spin_unlock_irqrestore(&ep->lock, flags);
1812		snd_usb_queue_pending_output_urbs(ep, false);
1813
1814		return;
1815	}
1816
1817	/*
1818	 * process after playback sync complete
1819	 *
1820	 * Full speed devices report feedback values in 10.14 format as samples
1821	 * per frame, high speed devices in 16.16 format as samples per
1822	 * microframe.
1823	 *
1824	 * Because the Audio Class 1 spec was written before USB 2.0, many high
1825	 * speed devices use a wrong interpretation, some others use an
1826	 * entirely different format.
1827	 *
1828	 * Therefore, we cannot predict what format any particular device uses
1829	 * and must detect it automatically.
1830	 */
1831
1832	if (urb->iso_frame_desc[0].status != 0 ||
1833	    urb->iso_frame_desc[0].actual_length < 3)
1834		return;
1835
1836	f = le32_to_cpup(urb->transfer_buffer);
1837	if (urb->iso_frame_desc[0].actual_length == 3)
1838		f &= 0x00ffffff;
1839	else
1840		f &= 0x0fffffff;
1841
1842	if (f == 0)
1843		return;
1844
1845	if (unlikely(sender->tenor_fb_quirk)) {
1846		/*
1847		 * Devices based on Tenor 8802 chipsets (TEAC UD-H01
1848		 * and others) sometimes change the feedback value
1849		 * by +/- 0x1.0000.
1850		 */
1851		if (f < ep->freqn - 0x8000)
1852			f += 0xf000;
1853		else if (f > ep->freqn + 0x8000)
1854			f -= 0xf000;
1855	} else if (unlikely(ep->freqshift == INT_MIN)) {
1856		/*
1857		 * The first time we see a feedback value, determine its format
1858		 * by shifting it left or right until it matches the nominal
1859		 * frequency value.  This assumes that the feedback does not
1860		 * differ from the nominal value more than +50% or -25%.
1861		 */
1862		shift = 0;
1863		while (f < ep->freqn - ep->freqn / 4) {
1864			f <<= 1;
1865			shift++;
1866		}
1867		while (f > ep->freqn + ep->freqn / 2) {
1868			f >>= 1;
1869			shift--;
1870		}
1871		ep->freqshift = shift;
1872	} else if (ep->freqshift >= 0)
1873		f <<= ep->freqshift;
1874	else
1875		f >>= -ep->freqshift;
1876
1877	if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {
1878		/*
1879		 * If the frequency looks valid, set it.
1880		 * This value is referred to in prepare_playback_urb().
1881		 */
1882		spin_lock_irqsave(&ep->lock, flags);
1883		ep->freqm = f;
1884		spin_unlock_irqrestore(&ep->lock, flags);
1885	} else {
1886		/*
1887		 * Out of range; maybe the shift value is wrong.
1888		 * Reset it so that we autodetect again the next time.
1889		 */
1890		ep->freqshift = INT_MIN;
1891	}
1892}
1893