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 */
 458void 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			return;
 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			else
 
 
 
 501				notify_xrun(ep);
 502			return;
 503		}
 504
 505		err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
 
 
 
 506		if (err < 0) {
 507			usb_audio_err(ep->chip,
 508				      "Unable to submit urb #%d: %d at %s\n",
 509				      ctx->index, err, __func__);
 510			notify_xrun(ep);
 511			return;
 
 
 
 512		}
 513
 514		set_bit(ctx->index, &ep->active_mask);
 515		atomic_inc(&ep->submitted_urbs);
 516	}
 
 
 517}
 518
 519/*
 520 * complete callback for urbs
 521 */
 522static void snd_complete_urb(struct urb *urb)
 523{
 524	struct snd_urb_ctx *ctx = urb->context;
 525	struct snd_usb_endpoint *ep = ctx->ep;
 526	int err;
 527
 528	if (unlikely(urb->status == -ENOENT ||		/* unlinked */
 529		     urb->status == -ENODEV ||		/* device removed */
 530		     urb->status == -ECONNRESET ||	/* unlinked */
 531		     urb->status == -ESHUTDOWN))	/* device disabled */
 532		goto exit_clear;
 533	/* device disconnected */
 534	if (unlikely(atomic_read(&ep->chip->shutdown)))
 535		goto exit_clear;
 536
 537	if (unlikely(!ep_state_running(ep)))
 538		goto exit_clear;
 539
 540	if (usb_pipeout(ep->pipe)) {
 541		retire_outbound_urb(ep, ctx);
 542		/* can be stopped during retire callback */
 543		if (unlikely(!ep_state_running(ep)))
 544			goto exit_clear;
 545
 546		/* in low-latency and implicit-feedback modes, push back the
 547		 * URB to ready list at first, then process as much as possible
 548		 */
 549		if (ep->lowlatency_playback ||
 550		     snd_usb_endpoint_implicit_feedback_sink(ep)) {
 551			push_back_to_ready_list(ep, ctx);
 552			clear_bit(ctx->index, &ep->active_mask);
 553			snd_usb_queue_pending_output_urbs(ep, false);
 554			atomic_dec(&ep->submitted_urbs); /* decrement at last */
 555			return;
 556		}
 557
 558		/* in non-lowlatency mode, no error handling for prepare */
 559		prepare_outbound_urb(ep, ctx, false);
 560		/* can be stopped during prepare callback */
 561		if (unlikely(!ep_state_running(ep)))
 562			goto exit_clear;
 563	} else {
 564		retire_inbound_urb(ep, ctx);
 565		/* can be stopped during retire callback */
 566		if (unlikely(!ep_state_running(ep)))
 567			goto exit_clear;
 568
 569		prepare_inbound_urb(ep, ctx);
 570	}
 571
 572	err = usb_submit_urb(urb, GFP_ATOMIC);
 
 
 
 573	if (err == 0)
 574		return;
 575
 576	usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
 577	notify_xrun(ep);
 
 
 578
 579exit_clear:
 580	clear_bit(ctx->index, &ep->active_mask);
 581	atomic_dec(&ep->submitted_urbs);
 582}
 583
 584/*
 585 * Find or create a refcount object for the given interface
 586 *
 587 * The objects are released altogether in snd_usb_endpoint_free_all()
 588 */
 589static struct snd_usb_iface_ref *
 590iface_ref_find(struct snd_usb_audio *chip, int iface)
 591{
 592	struct snd_usb_iface_ref *ip;
 593
 594	list_for_each_entry(ip, &chip->iface_ref_list, list)
 595		if (ip->iface == iface)
 596			return ip;
 597
 598	ip = kzalloc(sizeof(*ip), GFP_KERNEL);
 599	if (!ip)
 600		return NULL;
 601	ip->iface = iface;
 602	list_add_tail(&ip->list, &chip->iface_ref_list);
 603	return ip;
 604}
 605
 606/* Similarly, a refcount object for clock */
 607static struct snd_usb_clock_ref *
 608clock_ref_find(struct snd_usb_audio *chip, int clock)
 609{
 610	struct snd_usb_clock_ref *ref;
 611
 612	list_for_each_entry(ref, &chip->clock_ref_list, list)
 613		if (ref->clock == clock)
 614			return ref;
 615
 616	ref = kzalloc(sizeof(*ref), GFP_KERNEL);
 617	if (!ref)
 618		return NULL;
 619	ref->clock = clock;
 620	atomic_set(&ref->locked, 0);
 621	list_add_tail(&ref->list, &chip->clock_ref_list);
 622	return ref;
 623}
 624
 625/*
 626 * Get the existing endpoint object corresponding EP
 627 * Returns NULL if not present.
 628 */
 629struct snd_usb_endpoint *
 630snd_usb_get_endpoint(struct snd_usb_audio *chip, int ep_num)
 631{
 632	struct snd_usb_endpoint *ep;
 633
 634	list_for_each_entry(ep, &chip->ep_list, list) {
 635		if (ep->ep_num == ep_num)
 636			return ep;
 637	}
 638
 639	return NULL;
 640}
 641
 642#define ep_type_name(type) \
 643	(type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync")
 644
 645/**
 646 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
 647 *
 648 * @chip: The chip
 649 * @ep_num: The number of the endpoint to use
 650 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
 651 *
 652 * If the requested endpoint has not been added to the given chip before,
 653 * a new instance is created.
 654 *
 655 * Returns zero on success or a negative error code.
 656 *
 657 * New endpoints will be added to chip->ep_list and freed by
 658 * calling snd_usb_endpoint_free_all().
 659 *
 660 * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
 661 * bNumEndpoints > 1 beforehand.
 662 */
 663int snd_usb_add_endpoint(struct snd_usb_audio *chip, int ep_num, int type)
 664{
 665	struct snd_usb_endpoint *ep;
 666	bool is_playback;
 667
 668	ep = snd_usb_get_endpoint(chip, ep_num);
 669	if (ep)
 670		return 0;
 671
 672	usb_audio_dbg(chip, "Creating new %s endpoint #%x\n",
 673		      ep_type_name(type),
 674		      ep_num);
 675	ep = kzalloc(sizeof(*ep), GFP_KERNEL);
 676	if (!ep)
 677		return -ENOMEM;
 678
 679	ep->chip = chip;
 680	spin_lock_init(&ep->lock);
 681	ep->type = type;
 682	ep->ep_num = ep_num;
 683	INIT_LIST_HEAD(&ep->ready_playback_urbs);
 684	atomic_set(&ep->submitted_urbs, 0);
 685
 686	is_playback = ((ep_num & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT);
 687	ep_num &= USB_ENDPOINT_NUMBER_MASK;
 688	if (is_playback)
 689		ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
 690	else
 691		ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);
 692
 693	list_add_tail(&ep->list, &chip->ep_list);
 694	return 0;
 695}
 696
 697/* Set up syncinterval and maxsyncsize for a sync EP */
 698static void endpoint_set_syncinterval(struct snd_usb_audio *chip,
 699				      struct snd_usb_endpoint *ep)
 700{
 701	struct usb_host_interface *alts;
 702	struct usb_endpoint_descriptor *desc;
 703
 704	alts = snd_usb_get_host_interface(chip, ep->iface, ep->altsetting);
 705	if (!alts)
 706		return;
 707
 708	desc = get_endpoint(alts, ep->ep_idx);
 709	if (desc->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
 710	    desc->bRefresh >= 1 && desc->bRefresh <= 9)
 711		ep->syncinterval = desc->bRefresh;
 712	else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
 713		ep->syncinterval = 1;
 714	else if (desc->bInterval >= 1 && desc->bInterval <= 16)
 715		ep->syncinterval = desc->bInterval - 1;
 716	else
 717		ep->syncinterval = 3;
 718
 719	ep->syncmaxsize = le16_to_cpu(desc->wMaxPacketSize);
 720}
 721
 722static bool endpoint_compatible(struct snd_usb_endpoint *ep,
 723				const struct audioformat *fp,
 724				const struct snd_pcm_hw_params *params)
 725{
 726	if (!ep->opened)
 727		return false;
 728	if (ep->cur_audiofmt != fp)
 729		return false;
 730	if (ep->cur_rate != params_rate(params) ||
 731	    ep->cur_format != params_format(params) ||
 732	    ep->cur_period_frames != params_period_size(params) ||
 733	    ep->cur_buffer_periods != params_periods(params))
 734		return false;
 735	return true;
 736}
 737
 738/*
 739 * Check whether the given fp and hw params are compatible with the current
 740 * setup of the target EP for implicit feedback sync
 741 */
 742bool snd_usb_endpoint_compatible(struct snd_usb_audio *chip,
 743				 struct snd_usb_endpoint *ep,
 744				 const struct audioformat *fp,
 745				 const struct snd_pcm_hw_params *params)
 746{
 747	bool ret;
 748
 749	mutex_lock(&chip->mutex);
 750	ret = endpoint_compatible(ep, fp, params);
 751	mutex_unlock(&chip->mutex);
 752	return ret;
 753}
 754
 755/*
 756 * snd_usb_endpoint_open: Open the endpoint
 757 *
 758 * Called from hw_params to assign the endpoint to the substream.
 759 * It's reference-counted, and only the first opener is allowed to set up
 760 * arbitrary parameters.  The later opener must be compatible with the
 761 * former opened parameters.
 762 * The endpoint needs to be closed via snd_usb_endpoint_close() later.
 763 *
 764 * Note that this function doesn't configure the endpoint.  The substream
 765 * needs to set it up later via snd_usb_endpoint_set_params() and
 766 * snd_usb_endpoint_prepare().
 767 */
 768struct snd_usb_endpoint *
 769snd_usb_endpoint_open(struct snd_usb_audio *chip,
 770		      const struct audioformat *fp,
 771		      const struct snd_pcm_hw_params *params,
 772		      bool is_sync_ep,
 773		      bool fixed_rate)
 774{
 775	struct snd_usb_endpoint *ep;
 776	int ep_num = is_sync_ep ? fp->sync_ep : fp->endpoint;
 777
 778	mutex_lock(&chip->mutex);
 779	ep = snd_usb_get_endpoint(chip, ep_num);
 780	if (!ep) {
 781		usb_audio_err(chip, "Cannot find EP 0x%x to open\n", ep_num);
 782		goto unlock;
 783	}
 784
 785	if (!ep->opened) {
 786		if (is_sync_ep) {
 787			ep->iface = fp->sync_iface;
 788			ep->altsetting = fp->sync_altsetting;
 789			ep->ep_idx = fp->sync_ep_idx;
 790		} else {
 791			ep->iface = fp->iface;
 792			ep->altsetting = fp->altsetting;
 793			ep->ep_idx = fp->ep_idx;
 794		}
 795		usb_audio_dbg(chip, "Open EP 0x%x, iface=%d:%d, idx=%d\n",
 796			      ep_num, ep->iface, ep->altsetting, ep->ep_idx);
 797
 798		ep->iface_ref = iface_ref_find(chip, ep->iface);
 799		if (!ep->iface_ref) {
 800			ep = NULL;
 801			goto unlock;
 802		}
 803
 804		if (fp->protocol != UAC_VERSION_1) {
 805			ep->clock_ref = clock_ref_find(chip, fp->clock);
 806			if (!ep->clock_ref) {
 807				ep = NULL;
 808				goto unlock;
 809			}
 810			ep->clock_ref->opened++;
 811		}
 812
 813		ep->cur_audiofmt = fp;
 814		ep->cur_channels = fp->channels;
 815		ep->cur_rate = params_rate(params);
 816		ep->cur_format = params_format(params);
 817		ep->cur_frame_bytes = snd_pcm_format_physical_width(ep->cur_format) *
 818			ep->cur_channels / 8;
 819		ep->cur_period_frames = params_period_size(params);
 820		ep->cur_period_bytes = ep->cur_period_frames * ep->cur_frame_bytes;
 821		ep->cur_buffer_periods = params_periods(params);
 822
 823		if (ep->type == SND_USB_ENDPOINT_TYPE_SYNC)
 824			endpoint_set_syncinterval(chip, ep);
 825
 826		ep->implicit_fb_sync = fp->implicit_fb;
 827		ep->need_setup = true;
 828		ep->need_prepare = true;
 829		ep->fixed_rate = fixed_rate;
 830
 831		usb_audio_dbg(chip, "  channels=%d, rate=%d, format=%s, period_bytes=%d, periods=%d, implicit_fb=%d\n",
 832			      ep->cur_channels, ep->cur_rate,
 833			      snd_pcm_format_name(ep->cur_format),
 834			      ep->cur_period_bytes, ep->cur_buffer_periods,
 835			      ep->implicit_fb_sync);
 836
 837	} else {
 838		if (WARN_ON(!ep->iface_ref)) {
 839			ep = NULL;
 840			goto unlock;
 841		}
 842
 843		if (!endpoint_compatible(ep, fp, params)) {
 844			usb_audio_err(chip, "Incompatible EP setup for 0x%x\n",
 845				      ep_num);
 846			ep = NULL;
 847			goto unlock;
 848		}
 849
 850		usb_audio_dbg(chip, "Reopened EP 0x%x (count %d)\n",
 851			      ep_num, ep->opened);
 852	}
 853
 854	if (!ep->iface_ref->opened++)
 855		ep->iface_ref->need_setup = true;
 856
 857	ep->opened++;
 858
 859 unlock:
 860	mutex_unlock(&chip->mutex);
 861	return ep;
 862}
 863
 864/*
 865 * snd_usb_endpoint_set_sync: Link data and sync endpoints
 866 *
 867 * Pass NULL to sync_ep to unlink again
 868 */
 869void snd_usb_endpoint_set_sync(struct snd_usb_audio *chip,
 870			       struct snd_usb_endpoint *data_ep,
 871			       struct snd_usb_endpoint *sync_ep)
 872{
 873	data_ep->sync_source = sync_ep;
 874}
 875
 876/*
 877 * Set data endpoint callbacks and the assigned data stream
 878 *
 879 * Called at PCM trigger and cleanups.
 880 * Pass NULL to deactivate each callback.
 881 */
 882void snd_usb_endpoint_set_callback(struct snd_usb_endpoint *ep,
 883				   int (*prepare)(struct snd_usb_substream *subs,
 884						  struct urb *urb,
 885						  bool in_stream_lock),
 886				   void (*retire)(struct snd_usb_substream *subs,
 887						  struct urb *urb),
 888				   struct snd_usb_substream *data_subs)
 889{
 890	ep->prepare_data_urb = prepare;
 891	ep->retire_data_urb = retire;
 892	if (data_subs)
 893		ep->lowlatency_playback = data_subs->lowlatency_playback;
 894	else
 895		ep->lowlatency_playback = false;
 896	WRITE_ONCE(ep->data_subs, data_subs);
 897}
 898
 899static int endpoint_set_interface(struct snd_usb_audio *chip,
 900				  struct snd_usb_endpoint *ep,
 901				  bool set)
 902{
 903	int altset = set ? ep->altsetting : 0;
 904	int err;
 905
 906	if (ep->iface_ref->altset == altset)
 907		return 0;
 908
 909	usb_audio_dbg(chip, "Setting usb interface %d:%d for EP 0x%x\n",
 910		      ep->iface, altset, ep->ep_num);
 911	err = usb_set_interface(chip->dev, ep->iface, altset);
 912	if (err < 0) {
 913		usb_audio_err(chip, "%d:%d: usb_set_interface failed (%d)\n",
 914			      ep->iface, altset, err);
 
 915		return err;
 916	}
 917
 918	if (chip->quirk_flags & QUIRK_FLAG_IFACE_DELAY)
 919		msleep(50);
 920	ep->iface_ref->altset = altset;
 921	return 0;
 922}
 923
 924/*
 925 * snd_usb_endpoint_close: Close the endpoint
 926 *
 927 * Unreference the already opened endpoint via snd_usb_endpoint_open().
 928 */
 929void snd_usb_endpoint_close(struct snd_usb_audio *chip,
 930			    struct snd_usb_endpoint *ep)
 931{
 932	mutex_lock(&chip->mutex);
 933	usb_audio_dbg(chip, "Closing EP 0x%x (count %d)\n",
 934		      ep->ep_num, ep->opened);
 935
 936	if (!--ep->iface_ref->opened &&
 937		!(chip->quirk_flags & QUIRK_FLAG_IFACE_SKIP_CLOSE))
 938		endpoint_set_interface(chip, ep, false);
 939
 940	if (!--ep->opened) {
 941		if (ep->clock_ref) {
 942			if (!--ep->clock_ref->opened)
 943				ep->clock_ref->rate = 0;
 944		}
 945		ep->iface = 0;
 946		ep->altsetting = 0;
 947		ep->cur_audiofmt = NULL;
 948		ep->cur_rate = 0;
 949		ep->iface_ref = NULL;
 950		ep->clock_ref = NULL;
 951		usb_audio_dbg(chip, "EP 0x%x closed\n", ep->ep_num);
 952	}
 953	mutex_unlock(&chip->mutex);
 954}
 955
 956/* Prepare for suspening EP, called from the main suspend handler */
 957void snd_usb_endpoint_suspend(struct snd_usb_endpoint *ep)
 958{
 959	ep->need_prepare = true;
 960	if (ep->iface_ref)
 961		ep->iface_ref->need_setup = true;
 962	if (ep->clock_ref)
 963		ep->clock_ref->rate = 0;
 964}
 965
 966/*
 967 *  wait until all urbs are processed.
 968 */
 969static int wait_clear_urbs(struct snd_usb_endpoint *ep)
 970{
 971	unsigned long end_time = jiffies + msecs_to_jiffies(1000);
 972	int alive;
 973
 974	if (atomic_read(&ep->state) != EP_STATE_STOPPING)
 975		return 0;
 976
 977	do {
 978		alive = atomic_read(&ep->submitted_urbs);
 979		if (!alive)
 980			break;
 981
 982		schedule_timeout_uninterruptible(1);
 983	} while (time_before(jiffies, end_time));
 984
 985	if (alive)
 986		usb_audio_err(ep->chip,
 987			"timeout: still %d active urbs on EP #%x\n",
 988			alive, ep->ep_num);
 989
 990	if (ep_state_update(ep, EP_STATE_STOPPING, EP_STATE_STOPPED)) {
 991		ep->sync_sink = NULL;
 992		snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
 993	}
 994
 995	return 0;
 996}
 997
 998/* sync the pending stop operation;
 999 * this function itself doesn't trigger the stop operation
1000 */
1001void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
1002{
1003	if (ep)
1004		wait_clear_urbs(ep);
1005}
1006
1007/*
1008 * Stop active urbs
1009 *
1010 * This function moves the EP to STOPPING state if it's being RUNNING.
1011 */
1012static int stop_urbs(struct snd_usb_endpoint *ep, bool force, bool keep_pending)
1013{
1014	unsigned int i;
1015	unsigned long flags;
1016
1017	if (!force && atomic_read(&ep->running))
1018		return -EBUSY;
1019
1020	if (!ep_state_update(ep, EP_STATE_RUNNING, EP_STATE_STOPPING))
1021		return 0;
1022
1023	spin_lock_irqsave(&ep->lock, flags);
1024	INIT_LIST_HEAD(&ep->ready_playback_urbs);
1025	ep->next_packet_head = 0;
1026	ep->next_packet_queued = 0;
1027	spin_unlock_irqrestore(&ep->lock, flags);
1028
1029	if (keep_pending)
1030		return 0;
1031
1032	for (i = 0; i < ep->nurbs; i++) {
1033		if (test_bit(i, &ep->active_mask)) {
1034			if (!test_and_set_bit(i, &ep->unlink_mask)) {
1035				struct urb *u = ep->urb[i].urb;
1036				usb_unlink_urb(u);
1037			}
1038		}
1039	}
1040
1041	return 0;
1042}
1043
1044/*
1045 * release an endpoint's urbs
1046 */
1047static int release_urbs(struct snd_usb_endpoint *ep, bool force)
1048{
1049	int i, err;
1050
1051	/* route incoming urbs to nirvana */
1052	snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
1053
1054	/* stop and unlink urbs */
1055	err = stop_urbs(ep, force, false);
1056	if (err)
1057		return err;
1058
1059	wait_clear_urbs(ep);
1060
1061	for (i = 0; i < ep->nurbs; i++)
1062		release_urb_ctx(&ep->urb[i]);
1063
1064	usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
1065			  ep->syncbuf, ep->sync_dma);
1066
1067	ep->syncbuf = NULL;
1068	ep->nurbs = 0;
1069	return 0;
1070}
1071
1072/*
1073 * configure a data endpoint
1074 */
1075static int data_ep_set_params(struct snd_usb_endpoint *ep)
1076{
1077	struct snd_usb_audio *chip = ep->chip;
1078	unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
1079	unsigned int max_packs_per_period, urbs_per_period, urb_packs;
1080	unsigned int max_urbs, i;
1081	const struct audioformat *fmt = ep->cur_audiofmt;
1082	int frame_bits = ep->cur_frame_bytes * 8;
1083	int tx_length_quirk = (has_tx_length_quirk(chip) &&
1084			       usb_pipeout(ep->pipe));
1085
1086	usb_audio_dbg(chip, "Setting params for data EP 0x%x, pipe 0x%x\n",
1087		      ep->ep_num, ep->pipe);
1088
1089	if (ep->cur_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
1090		/*
1091		 * When operating in DSD DOP mode, the size of a sample frame
1092		 * in hardware differs from the actual physical format width
1093		 * because we need to make room for the DOP markers.
1094		 */
1095		frame_bits += ep->cur_channels << 3;
1096	}
1097
1098	ep->datainterval = fmt->datainterval;
1099	ep->stride = frame_bits >> 3;
1100
1101	switch (ep->cur_format) {
1102	case SNDRV_PCM_FORMAT_U8:
1103		ep->silence_value = 0x80;
1104		break;
1105	case SNDRV_PCM_FORMAT_DSD_U8:
1106	case SNDRV_PCM_FORMAT_DSD_U16_LE:
1107	case SNDRV_PCM_FORMAT_DSD_U32_LE:
1108	case SNDRV_PCM_FORMAT_DSD_U16_BE:
1109	case SNDRV_PCM_FORMAT_DSD_U32_BE:
1110		ep->silence_value = 0x69;
1111		break;
1112	default:
1113		ep->silence_value = 0;
1114	}
1115
1116	/* assume max. frequency is 50% higher than nominal */
1117	ep->freqmax = ep->freqn + (ep->freqn >> 1);
1118	/* Round up freqmax to nearest integer in order to calculate maximum
1119	 * packet size, which must represent a whole number of frames.
1120	 * This is accomplished by adding 0x0.ffff before converting the
1121	 * Q16.16 format into integer.
1122	 * In order to accurately calculate the maximum packet size when
1123	 * the data interval is more than 1 (i.e. ep->datainterval > 0),
1124	 * multiply by the data interval prior to rounding. For instance,
1125	 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
1126	 * frames with a data interval of 1, but 11 (10.25) frames with a
1127	 * data interval of 2.
1128	 * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
1129	 * maximum datainterval value of 3, at USB full speed, higher for
1130	 * USB high speed, noting that ep->freqmax is in units of
1131	 * frames per packet in Q16.16 format.)
1132	 */
1133	maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
1134			 (frame_bits >> 3);
1135	if (tx_length_quirk)
1136		maxsize += sizeof(__le32); /* Space for length descriptor */
1137	/* but wMaxPacketSize might reduce this */
1138	if (ep->maxpacksize && ep->maxpacksize < maxsize) {
1139		/* whatever fits into a max. size packet */
1140		unsigned int data_maxsize = maxsize = ep->maxpacksize;
1141
1142		if (tx_length_quirk)
1143			/* Need to remove the length descriptor to calc freq */
1144			data_maxsize -= sizeof(__le32);
1145		ep->freqmax = (data_maxsize / (frame_bits >> 3))
1146				<< (16 - ep->datainterval);
1147	}
1148
1149	if (ep->fill_max)
1150		ep->curpacksize = ep->maxpacksize;
1151	else
1152		ep->curpacksize = maxsize;
1153
1154	if (snd_usb_get_speed(chip->dev) != USB_SPEED_FULL) {
1155		packs_per_ms = 8 >> ep->datainterval;
1156		max_packs_per_urb = MAX_PACKS_HS;
1157	} else {
1158		packs_per_ms = 1;
1159		max_packs_per_urb = MAX_PACKS;
1160	}
1161	if (ep->sync_source && !ep->implicit_fb_sync)
1162		max_packs_per_urb = min(max_packs_per_urb,
1163					1U << ep->sync_source->syncinterval);
1164	max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);
1165
1166	/*
1167	 * Capture endpoints need to use small URBs because there's no way
1168	 * to tell in advance where the next period will end, and we don't
1169	 * want the next URB to complete much after the period ends.
1170	 *
1171	 * Playback endpoints with implicit sync much use the same parameters
1172	 * as their corresponding capture endpoint.
1173	 */
1174	if (usb_pipein(ep->pipe) || ep->implicit_fb_sync) {
1175
1176		urb_packs = packs_per_ms;
1177		/*
1178		 * Wireless devices can poll at a max rate of once per 4ms.
1179		 * For dataintervals less than 5, increase the packet count to
1180		 * allow the host controller to use bursting to fill in the
1181		 * gaps.
1182		 */
1183		if (snd_usb_get_speed(chip->dev) == USB_SPEED_WIRELESS) {
1184			int interval = ep->datainterval;
1185			while (interval < 5) {
1186				urb_packs <<= 1;
1187				++interval;
1188			}
1189		}
1190		/* make capture URBs <= 1 ms and smaller than a period */
1191		urb_packs = min(max_packs_per_urb, urb_packs);
1192		while (urb_packs > 1 && urb_packs * maxsize >= ep->cur_period_bytes)
1193			urb_packs >>= 1;
1194		ep->nurbs = MAX_URBS;
1195
1196	/*
1197	 * Playback endpoints without implicit sync are adjusted so that
1198	 * a period fits as evenly as possible in the smallest number of
1199	 * URBs.  The total number of URBs is adjusted to the size of the
1200	 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
1201	 */
1202	} else {
1203		/* determine how small a packet can be */
1204		minsize = (ep->freqn >> (16 - ep->datainterval)) *
1205				(frame_bits >> 3);
1206		/* with sync from device, assume it can be 12% lower */
1207		if (ep->sync_source)
1208			minsize -= minsize >> 3;
1209		minsize = max(minsize, 1u);
1210
1211		/* how many packets will contain an entire ALSA period? */
1212		max_packs_per_period = DIV_ROUND_UP(ep->cur_period_bytes, minsize);
1213
1214		/* how many URBs will contain a period? */
1215		urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
1216				max_packs_per_urb);
1217		/* how many packets are needed in each URB? */
1218		urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);
1219
1220		/* limit the number of frames in a single URB */
1221		ep->max_urb_frames = DIV_ROUND_UP(ep->cur_period_frames,
1222						  urbs_per_period);
1223
1224		/* try to use enough URBs to contain an entire ALSA buffer */
1225		max_urbs = min((unsigned) MAX_URBS,
1226				MAX_QUEUE * packs_per_ms / urb_packs);
1227		ep->nurbs = min(max_urbs, urbs_per_period * ep->cur_buffer_periods);
1228	}
1229
1230	/* allocate and initialize data urbs */
1231	for (i = 0; i < ep->nurbs; i++) {
1232		struct snd_urb_ctx *u = &ep->urb[i];
1233		u->index = i;
1234		u->ep = ep;
1235		u->packets = urb_packs;
1236		u->buffer_size = maxsize * u->packets;
1237
1238		if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
1239			u->packets++; /* for transfer delimiter */
1240		u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
1241		if (!u->urb)
1242			goto out_of_memory;
1243
1244		u->urb->transfer_buffer =
1245			usb_alloc_coherent(chip->dev, u->buffer_size,
1246					   GFP_KERNEL, &u->urb->transfer_dma);
1247		if (!u->urb->transfer_buffer)
1248			goto out_of_memory;
1249		u->urb->pipe = ep->pipe;
1250		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
1251		u->urb->interval = 1 << ep->datainterval;
1252		u->urb->context = u;
1253		u->urb->complete = snd_complete_urb;
1254		INIT_LIST_HEAD(&u->ready_list);
1255	}
1256
1257	return 0;
1258
1259out_of_memory:
1260	release_urbs(ep, false);
1261	return -ENOMEM;
1262}
1263
1264/*
1265 * configure a sync endpoint
1266 */
1267static int sync_ep_set_params(struct snd_usb_endpoint *ep)
1268{
1269	struct snd_usb_audio *chip = ep->chip;
1270	int i;
1271
1272	usb_audio_dbg(chip, "Setting params for sync EP 0x%x, pipe 0x%x\n",
1273		      ep->ep_num, ep->pipe);
1274
1275	ep->syncbuf = usb_alloc_coherent(chip->dev, SYNC_URBS * 4,
1276					 GFP_KERNEL, &ep->sync_dma);
1277	if (!ep->syncbuf)
1278		return -ENOMEM;
1279
1280	ep->nurbs = SYNC_URBS;
1281	for (i = 0; i < SYNC_URBS; i++) {
1282		struct snd_urb_ctx *u = &ep->urb[i];
1283		u->index = i;
1284		u->ep = ep;
1285		u->packets = 1;
1286		u->urb = usb_alloc_urb(1, GFP_KERNEL);
1287		if (!u->urb)
1288			goto out_of_memory;
1289		u->urb->transfer_buffer = ep->syncbuf + i * 4;
1290		u->urb->transfer_dma = ep->sync_dma + i * 4;
1291		u->urb->transfer_buffer_length = 4;
1292		u->urb->pipe = ep->pipe;
1293		u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
1294		u->urb->number_of_packets = 1;
1295		u->urb->interval = 1 << ep->syncinterval;
1296		u->urb->context = u;
1297		u->urb->complete = snd_complete_urb;
1298	}
1299
1300	return 0;
1301
1302out_of_memory:
1303	release_urbs(ep, false);
1304	return -ENOMEM;
1305}
1306
1307/* update the rate of the referred clock; return the actual rate */
1308static int update_clock_ref_rate(struct snd_usb_audio *chip,
1309				 struct snd_usb_endpoint *ep)
1310{
1311	struct snd_usb_clock_ref *clock = ep->clock_ref;
1312	int rate = ep->cur_rate;
1313
1314	if (!clock || clock->rate == rate)
1315		return rate;
1316	if (clock->rate) {
1317		if (atomic_read(&clock->locked))
1318			return clock->rate;
1319		if (clock->rate != rate) {
1320			usb_audio_err(chip, "Mismatched sample rate %d vs %d for EP 0x%x\n",
1321				      clock->rate, rate, ep->ep_num);
1322			return clock->rate;
1323		}
1324	}
1325	clock->rate = rate;
1326	clock->need_setup = true;
1327	return rate;
1328}
1329
1330/*
1331 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
1332 *
1333 * It's called either from hw_params callback.
1334 * Determine the number of URBs to be used on this endpoint.
1335 * An endpoint must be configured before it can be started.
1336 * An endpoint that is already running can not be reconfigured.
1337 */
1338int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
1339				struct snd_usb_endpoint *ep)
1340{
1341	const struct audioformat *fmt = ep->cur_audiofmt;
1342	int err = 0;
1343
1344	mutex_lock(&chip->mutex);
1345	if (!ep->need_setup)
1346		goto unlock;
1347
1348	/* release old buffers, if any */
1349	err = release_urbs(ep, false);
1350	if (err < 0)
1351		goto unlock;
1352
1353	ep->datainterval = fmt->datainterval;
1354	ep->maxpacksize = fmt->maxpacksize;
1355	ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
1356
1357	if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL) {
1358		ep->freqn = get_usb_full_speed_rate(ep->cur_rate);
1359		ep->pps = 1000 >> ep->datainterval;
1360	} else {
1361		ep->freqn = get_usb_high_speed_rate(ep->cur_rate);
1362		ep->pps = 8000 >> ep->datainterval;
1363	}
1364
1365	ep->sample_rem = ep->cur_rate % ep->pps;
1366	ep->packsize[0] = ep->cur_rate / ep->pps;
1367	ep->packsize[1] = (ep->cur_rate + (ep->pps - 1)) / ep->pps;
1368
1369	/* calculate the frequency in 16.16 format */
1370	ep->freqm = ep->freqn;
1371	ep->freqshift = INT_MIN;
1372
1373	ep->phase = 0;
1374
1375	switch (ep->type) {
1376	case  SND_USB_ENDPOINT_TYPE_DATA:
1377		err = data_ep_set_params(ep);
1378		break;
1379	case  SND_USB_ENDPOINT_TYPE_SYNC:
1380		err = sync_ep_set_params(ep);
1381		break;
1382	default:
1383		err = -EINVAL;
1384	}
1385
1386	usb_audio_dbg(chip, "Set up %d URBS, ret=%d\n", ep->nurbs, err);
1387
1388	if (err < 0)
1389		goto unlock;
1390
1391	/* some unit conversions in runtime */
1392	ep->maxframesize = ep->maxpacksize / ep->cur_frame_bytes;
1393	ep->curframesize = ep->curpacksize / ep->cur_frame_bytes;
1394
1395	err = update_clock_ref_rate(chip, ep);
1396	if (err >= 0) {
1397		ep->need_setup = false;
1398		err = 0;
1399	}
1400
1401 unlock:
1402	mutex_unlock(&chip->mutex);
1403	return err;
1404}
1405
1406static int init_sample_rate(struct snd_usb_audio *chip,
1407			    struct snd_usb_endpoint *ep)
1408{
1409	struct snd_usb_clock_ref *clock = ep->clock_ref;
1410	int rate, err;
1411
1412	rate = update_clock_ref_rate(chip, ep);
1413	if (rate < 0)
1414		return rate;
1415	if (clock && !clock->need_setup)
1416		return 0;
1417
1418	if (!ep->fixed_rate) {
1419		err = snd_usb_init_sample_rate(chip, ep->cur_audiofmt, rate);
1420		if (err < 0) {
1421			if (clock)
1422				clock->rate = 0; /* reset rate */
1423			return err;
1424		}
1425	}
1426
1427	if (clock)
1428		clock->need_setup = false;
1429	return 0;
1430}
1431
1432/*
1433 * snd_usb_endpoint_prepare: Prepare the endpoint
1434 *
1435 * This function sets up the EP to be fully usable state.
1436 * It's called either from prepare callback.
1437 * The function checks need_setup flag, and performs nothing unless needed,
1438 * so it's safe to call this multiple times.
1439 *
1440 * This returns zero if unchanged, 1 if the configuration has changed,
1441 * or a negative error code.
1442 */
1443int snd_usb_endpoint_prepare(struct snd_usb_audio *chip,
1444			     struct snd_usb_endpoint *ep)
1445{
1446	bool iface_first;
1447	int err = 0;
1448
1449	mutex_lock(&chip->mutex);
1450	if (WARN_ON(!ep->iface_ref))
1451		goto unlock;
1452	if (!ep->need_prepare)
1453		goto unlock;
1454
1455	/* If the interface has been already set up, just set EP parameters */
1456	if (!ep->iface_ref->need_setup) {
1457		/* sample rate setup of UAC1 is per endpoint, and we need
1458		 * to update at each EP configuration
1459		 */
1460		if (ep->cur_audiofmt->protocol == UAC_VERSION_1) {
1461			err = init_sample_rate(chip, ep);
1462			if (err < 0)
1463				goto unlock;
1464		}
1465		goto done;
1466	}
1467
1468	/* Need to deselect altsetting at first */
1469	endpoint_set_interface(chip, ep, false);
1470
1471	/* Some UAC1 devices (e.g. Yamaha THR10) need the host interface
1472	 * to be set up before parameter setups
1473	 */
1474	iface_first = ep->cur_audiofmt->protocol == UAC_VERSION_1;
1475	/* Workaround for devices that require the interface setup at first like UAC1 */
1476	if (chip->quirk_flags & QUIRK_FLAG_SET_IFACE_FIRST)
1477		iface_first = true;
1478	if (iface_first) {
1479		err = endpoint_set_interface(chip, ep, true);
1480		if (err < 0)
1481			goto unlock;
1482	}
1483
1484	err = snd_usb_init_pitch(chip, ep->cur_audiofmt);
1485	if (err < 0)
1486		goto unlock;
1487
1488	err = init_sample_rate(chip, ep);
1489	if (err < 0)
1490		goto unlock;
1491
1492	err = snd_usb_select_mode_quirk(chip, ep->cur_audiofmt);
1493	if (err < 0)
1494		goto unlock;
1495
1496	/* for UAC2/3, enable the interface altset here at last */
1497	if (!iface_first) {
1498		err = endpoint_set_interface(chip, ep, true);
1499		if (err < 0)
1500			goto unlock;
1501	}
1502
1503	ep->iface_ref->need_setup = false;
1504
1505 done:
1506	ep->need_prepare = false;
1507	err = 1;
1508
1509unlock:
1510	mutex_unlock(&chip->mutex);
1511	return err;
1512}
1513
1514/* get the current rate set to the given clock by any endpoint */
1515int snd_usb_endpoint_get_clock_rate(struct snd_usb_audio *chip, int clock)
1516{
1517	struct snd_usb_clock_ref *ref;
1518	int rate = 0;
1519
1520	if (!clock)
1521		return 0;
1522	mutex_lock(&chip->mutex);
1523	list_for_each_entry(ref, &chip->clock_ref_list, list) {
1524		if (ref->clock == clock) {
1525			rate = ref->rate;
1526			break;
1527		}
1528	}
1529	mutex_unlock(&chip->mutex);
1530	return rate;
1531}
1532
1533/**
1534 * snd_usb_endpoint_start: start an snd_usb_endpoint
1535 *
1536 * @ep: the endpoint to start
1537 *
1538 * A call to this function will increment the running count of the endpoint.
1539 * In case it is not already running, the URBs for this endpoint will be
1540 * submitted. Otherwise, this function does nothing.
1541 *
1542 * Must be balanced to calls of snd_usb_endpoint_stop().
1543 *
1544 * Returns an error if the URB submission failed, 0 in all other cases.
1545 */
1546int snd_usb_endpoint_start(struct snd_usb_endpoint *ep)
1547{
1548	bool is_playback = usb_pipeout(ep->pipe);
1549	int err;
1550	unsigned int i;
1551
1552	if (atomic_read(&ep->chip->shutdown))
1553		return -EBADFD;
1554
1555	if (ep->sync_source)
1556		WRITE_ONCE(ep->sync_source->sync_sink, ep);
1557
1558	usb_audio_dbg(ep->chip, "Starting %s EP 0x%x (running %d)\n",
1559		      ep_type_name(ep->type), ep->ep_num,
1560		      atomic_read(&ep->running));
1561
1562	/* already running? */
1563	if (atomic_inc_return(&ep->running) != 1)
1564		return 0;
1565
1566	if (ep->clock_ref)
1567		atomic_inc(&ep->clock_ref->locked);
1568
1569	ep->active_mask = 0;
1570	ep->unlink_mask = 0;
1571	ep->phase = 0;
1572	ep->sample_accum = 0;
1573
1574	snd_usb_endpoint_start_quirk(ep);
1575
1576	/*
1577	 * If this endpoint has a data endpoint as implicit feedback source,
1578	 * don't start the urbs here. Instead, mark them all as available,
1579	 * wait for the record urbs to return and queue the playback urbs
1580	 * from that context.
1581	 */
1582
1583	if (!ep_state_update(ep, EP_STATE_STOPPED, EP_STATE_RUNNING))
1584		goto __error;
1585
1586	if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1587	    !(ep->chip->quirk_flags & QUIRK_FLAG_PLAYBACK_FIRST)) {
1588		usb_audio_dbg(ep->chip, "No URB submission due to implicit fb sync\n");
1589		i = 0;
1590		goto fill_rest;
1591	}
1592
1593	for (i = 0; i < ep->nurbs; i++) {
1594		struct urb *urb = ep->urb[i].urb;
1595
1596		if (snd_BUG_ON(!urb))
1597			goto __error;
1598
1599		if (is_playback)
1600			err = prepare_outbound_urb(ep, urb->context, true);
1601		else
1602			err = prepare_inbound_urb(ep, urb->context);
1603		if (err < 0) {
1604			/* stop filling at applptr */
1605			if (err == -EAGAIN)
1606				break;
1607			usb_audio_dbg(ep->chip,
1608				      "EP 0x%x: failed to prepare urb: %d\n",
1609				      ep->ep_num, err);
1610			goto __error;
1611		}
1612
1613		err = usb_submit_urb(urb, GFP_ATOMIC);
 
 
 
1614		if (err < 0) {
1615			usb_audio_err(ep->chip,
1616				"cannot submit urb %d, error %d: %s\n",
1617				i, err, usb_error_string(err));
 
1618			goto __error;
1619		}
1620		set_bit(i, &ep->active_mask);
1621		atomic_inc(&ep->submitted_urbs);
1622	}
1623
1624	if (!i) {
1625		usb_audio_dbg(ep->chip, "XRUN at starting EP 0x%x\n",
1626			      ep->ep_num);
1627		goto __error;
1628	}
1629
1630	usb_audio_dbg(ep->chip, "%d URBs submitted for EP 0x%x\n",
1631		      i, ep->ep_num);
1632
1633 fill_rest:
1634	/* put the remaining URBs to ready list */
1635	if (is_playback) {
1636		for (; i < ep->nurbs; i++)
1637			push_back_to_ready_list(ep, ep->urb + i);
1638	}
1639
1640	return 0;
1641
1642__error:
1643	snd_usb_endpoint_stop(ep, false);
1644	return -EPIPE;
1645}
1646
1647/**
1648 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
1649 *
1650 * @ep: the endpoint to stop (may be NULL)
1651 * @keep_pending: keep in-flight URBs
1652 *
1653 * A call to this function will decrement the running count of the endpoint.
1654 * In case the last user has requested the endpoint stop, the URBs will
1655 * actually be deactivated.
1656 *
1657 * Must be balanced to calls of snd_usb_endpoint_start().
1658 *
1659 * The caller needs to synchronize the pending stop operation via
1660 * snd_usb_endpoint_sync_pending_stop().
1661 */
1662void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep, bool keep_pending)
1663{
1664	if (!ep)
1665		return;
1666
1667	usb_audio_dbg(ep->chip, "Stopping %s EP 0x%x (running %d)\n",
1668		      ep_type_name(ep->type), ep->ep_num,
1669		      atomic_read(&ep->running));
1670
1671	if (snd_BUG_ON(!atomic_read(&ep->running)))
1672		return;
1673
1674	if (!atomic_dec_return(&ep->running)) {
1675		if (ep->sync_source)
1676			WRITE_ONCE(ep->sync_source->sync_sink, NULL);
1677		stop_urbs(ep, false, keep_pending);
1678		if (ep->clock_ref)
1679			atomic_dec(&ep->clock_ref->locked);
1680
1681		if (ep->chip->quirk_flags & QUIRK_FLAG_FORCE_IFACE_RESET &&
1682		    usb_pipeout(ep->pipe)) {
1683			ep->need_prepare = true;
1684			if (ep->iface_ref)
1685				ep->iface_ref->need_setup = true;
1686		}
1687	}
1688}
1689
1690/**
1691 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
1692 *
1693 * @ep: the endpoint to release
1694 *
1695 * This function does not care for the endpoint's running count but will tear
1696 * down all the streaming URBs immediately.
1697 */
1698void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
1699{
1700	release_urbs(ep, true);
1701}
1702
1703/**
1704 * snd_usb_endpoint_free_all: Free the resources of an snd_usb_endpoint
1705 * @chip: The chip
1706 *
1707 * This free all endpoints and those resources
1708 */
1709void snd_usb_endpoint_free_all(struct snd_usb_audio *chip)
1710{
1711	struct snd_usb_endpoint *ep, *en;
1712	struct snd_usb_iface_ref *ip, *in;
1713	struct snd_usb_clock_ref *cp, *cn;
1714
1715	list_for_each_entry_safe(ep, en, &chip->ep_list, list)
1716		kfree(ep);
1717
1718	list_for_each_entry_safe(ip, in, &chip->iface_ref_list, list)
1719		kfree(ip);
1720
1721	list_for_each_entry_safe(cp, cn, &chip->clock_ref_list, list)
1722		kfree(cp);
1723}
1724
1725/*
1726 * snd_usb_handle_sync_urb: parse an USB sync packet
1727 *
1728 * @ep: the endpoint to handle the packet
1729 * @sender: the sending endpoint
1730 * @urb: the received packet
1731 *
1732 * This function is called from the context of an endpoint that received
1733 * the packet and is used to let another endpoint object handle the payload.
1734 */
1735static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
1736				    struct snd_usb_endpoint *sender,
1737				    const struct urb *urb)
1738{
1739	int shift;
1740	unsigned int f;
1741	unsigned long flags;
1742
1743	snd_BUG_ON(ep == sender);
1744
1745	/*
1746	 * In case the endpoint is operating in implicit feedback mode, prepare
1747	 * a new outbound URB that has the same layout as the received packet
1748	 * and add it to the list of pending urbs. queue_pending_output_urbs()
1749	 * will take care of them later.
1750	 */
1751	if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1752	    atomic_read(&ep->running)) {
1753
1754		/* implicit feedback case */
1755		int i, bytes = 0;
1756		struct snd_urb_ctx *in_ctx;
1757		struct snd_usb_packet_info *out_packet;
1758
1759		in_ctx = urb->context;
1760
1761		/* Count overall packet size */
1762		for (i = 0; i < in_ctx->packets; i++)
1763			if (urb->iso_frame_desc[i].status == 0)
1764				bytes += urb->iso_frame_desc[i].actual_length;
1765
1766		/*
1767		 * skip empty packets. At least M-Audio's Fast Track Ultra stops
1768		 * streaming once it received a 0-byte OUT URB
1769		 */
1770		if (bytes == 0)
1771			return;
1772
1773		spin_lock_irqsave(&ep->lock, flags);
1774		if (ep->next_packet_queued >= ARRAY_SIZE(ep->next_packet)) {
1775			spin_unlock_irqrestore(&ep->lock, flags);
1776			usb_audio_err(ep->chip,
1777				      "next package FIFO overflow EP 0x%x\n",
1778				      ep->ep_num);
1779			notify_xrun(ep);
1780			return;
1781		}
1782
1783		out_packet = next_packet_fifo_enqueue(ep);
1784
1785		/*
1786		 * Iterate through the inbound packet and prepare the lengths
1787		 * for the output packet. The OUT packet we are about to send
1788		 * will have the same amount of payload bytes per stride as the
1789		 * IN packet we just received. Since the actual size is scaled
1790		 * by the stride, use the sender stride to calculate the length
1791		 * in case the number of channels differ between the implicitly
1792		 * fed-back endpoint and the synchronizing endpoint.
1793		 */
1794
1795		out_packet->packets = in_ctx->packets;
1796		for (i = 0; i < in_ctx->packets; i++) {
1797			if (urb->iso_frame_desc[i].status == 0)
1798				out_packet->packet_size[i] =
1799					urb->iso_frame_desc[i].actual_length / sender->stride;
1800			else
1801				out_packet->packet_size[i] = 0;
1802		}
1803
1804		spin_unlock_irqrestore(&ep->lock, flags);
1805		snd_usb_queue_pending_output_urbs(ep, false);
1806
1807		return;
1808	}
1809
1810	/*
1811	 * process after playback sync complete
1812	 *
1813	 * Full speed devices report feedback values in 10.14 format as samples
1814	 * per frame, high speed devices in 16.16 format as samples per
1815	 * microframe.
1816	 *
1817	 * Because the Audio Class 1 spec was written before USB 2.0, many high
1818	 * speed devices use a wrong interpretation, some others use an
1819	 * entirely different format.
1820	 *
1821	 * Therefore, we cannot predict what format any particular device uses
1822	 * and must detect it automatically.
1823	 */
1824
1825	if (urb->iso_frame_desc[0].status != 0 ||
1826	    urb->iso_frame_desc[0].actual_length < 3)
1827		return;
1828
1829	f = le32_to_cpup(urb->transfer_buffer);
1830	if (urb->iso_frame_desc[0].actual_length == 3)
1831		f &= 0x00ffffff;
1832	else
1833		f &= 0x0fffffff;
1834
1835	if (f == 0)
1836		return;
1837
1838	if (unlikely(sender->tenor_fb_quirk)) {
1839		/*
1840		 * Devices based on Tenor 8802 chipsets (TEAC UD-H01
1841		 * and others) sometimes change the feedback value
1842		 * by +/- 0x1.0000.
1843		 */
1844		if (f < ep->freqn - 0x8000)
1845			f += 0xf000;
1846		else if (f > ep->freqn + 0x8000)
1847			f -= 0xf000;
1848	} else if (unlikely(ep->freqshift == INT_MIN)) {
1849		/*
1850		 * The first time we see a feedback value, determine its format
1851		 * by shifting it left or right until it matches the nominal
1852		 * frequency value.  This assumes that the feedback does not
1853		 * differ from the nominal value more than +50% or -25%.
1854		 */
1855		shift = 0;
1856		while (f < ep->freqn - ep->freqn / 4) {
1857			f <<= 1;
1858			shift++;
1859		}
1860		while (f > ep->freqn + ep->freqn / 2) {
1861			f >>= 1;
1862			shift--;
1863		}
1864		ep->freqshift = shift;
1865	} else if (ep->freqshift >= 0)
1866		f <<= ep->freqshift;
1867	else
1868		f >>= -ep->freqshift;
1869
1870	if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {
1871		/*
1872		 * If the frequency looks valid, set it.
1873		 * This value is referred to in prepare_playback_urb().
1874		 */
1875		spin_lock_irqsave(&ep->lock, flags);
1876		ep->freqm = f;
1877		spin_unlock_irqrestore(&ep->lock, flags);
1878	} else {
1879		/*
1880		 * Out of range; maybe the shift value is wrong.
1881		 * Reset it so that we autodetect again the next time.
1882		 */
1883		ep->freqshift = INT_MIN;
1884	}
1885}
1886