1 // SPDX-License-Identifier: GPL-2.0-or-later
6 #include <linux/init.h>
7 #include <linux/ratelimit.h>
9 #include <linux/usb/audio.h>
10 #include <linux/slab.h>
12 #include <sound/core.h>
13 #include <sound/pcm.h>
14 #include <sound/pcm_params.h>
30 /* interface refcounting */
31 struct snd_usb_iface_ref {
35 struct list_head list;
39 * snd_usb_endpoint is a model that abstracts everything related to an
40 * USB endpoint and its streaming.
42 * There are functions to activate and deactivate the streaming URBs and
43 * optional callbacks to let the pcm logic handle the actual content of the
44 * packets for playback and record. Thus, the bus streaming and the audio
45 * handlers are fully decoupled.
47 * There are two different types of endpoints in audio applications.
49 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both
50 * inbound and outbound traffic.
52 * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and
53 * expect the payload to carry Q10.14 / Q16.16 formatted sync information
56 * Each endpoint has to be configured prior to being used by calling
57 * snd_usb_endpoint_set_params().
59 * The model incorporates a reference counting, so that multiple users
60 * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and
61 * only the first user will effectively start the URBs, and only the last
62 * one to stop it will tear the URBs down again.
66 * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
67 * this will overflow at approx 524 kHz
69 static inline unsigned get_usb_full_speed_rate(unsigned int rate)
71 return ((rate << 13) + 62) / 125;
75 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
76 * this will overflow at approx 4 MHz
78 static inline unsigned get_usb_high_speed_rate(unsigned int rate)
80 return ((rate << 10) + 62) / 125;
86 static void release_urb_ctx(struct snd_urb_ctx *u)
89 usb_free_coherent(u->ep->chip->dev, u->buffer_size,
90 u->urb->transfer_buffer,
91 u->urb->transfer_dma);
96 static const char *usb_error_string(int err)
102 return "endpoint not enabled";
104 return "endpoint stalled";
106 return "not enough bandwidth";
108 return "device disabled";
110 return "device suspended";
115 return "internal error";
117 return "unknown error";
121 static inline bool ep_state_running(struct snd_usb_endpoint *ep)
123 return atomic_read(&ep->state) == EP_STATE_RUNNING;
126 static inline bool ep_state_update(struct snd_usb_endpoint *ep, int old, int new)
128 return atomic_cmpxchg(&ep->state, old, new) == old;
132 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type
134 * @ep: The snd_usb_endpoint
136 * Determine whether an endpoint is driven by an implicit feedback
137 * data endpoint source.
139 int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep)
141 return ep->implicit_fb_sync && usb_pipeout(ep->pipe);
145 * Return the number of samples to be sent in the next packet
146 * for streaming based on information derived from sync endpoints
148 * This won't be used for implicit feedback which takes the packet size
149 * returned from the sync source
151 static int slave_next_packet_size(struct snd_usb_endpoint *ep)
157 return ep->maxframesize;
159 spin_lock_irqsave(&ep->lock, flags);
160 ep->phase = (ep->phase & 0xffff)
161 + (ep->freqm << ep->datainterval);
162 ret = min(ep->phase >> 16, ep->maxframesize);
163 spin_unlock_irqrestore(&ep->lock, flags);
169 * Return the number of samples to be sent in the next packet
170 * for adaptive and synchronous endpoints
172 static int next_packet_size(struct snd_usb_endpoint *ep)
177 return ep->maxframesize;
179 ep->sample_accum += ep->sample_rem;
180 if (ep->sample_accum >= ep->pps) {
181 ep->sample_accum -= ep->pps;
182 ret = ep->packsize[1];
184 ret = ep->packsize[0];
191 * snd_usb_endpoint_next_packet_size: Return the number of samples to be sent
194 int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep,
195 struct snd_urb_ctx *ctx, int idx)
197 if (ctx->packet_size[idx])
198 return ctx->packet_size[idx];
199 else if (ep->sync_source)
200 return slave_next_packet_size(ep);
202 return next_packet_size(ep);
205 static void call_retire_callback(struct snd_usb_endpoint *ep,
208 struct snd_usb_substream *data_subs;
210 data_subs = READ_ONCE(ep->data_subs);
211 if (data_subs && ep->retire_data_urb)
212 ep->retire_data_urb(data_subs, urb);
215 static void retire_outbound_urb(struct snd_usb_endpoint *ep,
216 struct snd_urb_ctx *urb_ctx)
218 call_retire_callback(ep, urb_ctx->urb);
221 static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
222 struct snd_usb_endpoint *sender,
223 const struct urb *urb);
225 static void retire_inbound_urb(struct snd_usb_endpoint *ep,
226 struct snd_urb_ctx *urb_ctx)
228 struct urb *urb = urb_ctx->urb;
229 struct snd_usb_endpoint *sync_sink;
231 if (unlikely(ep->skip_packets > 0)) {
236 sync_sink = READ_ONCE(ep->sync_sink);
238 snd_usb_handle_sync_urb(sync_sink, ep, urb);
240 call_retire_callback(ep, urb);
243 static void prepare_silent_urb(struct snd_usb_endpoint *ep,
244 struct snd_urb_ctx *ctx)
246 struct urb *urb = ctx->urb;
247 unsigned int offs = 0;
248 unsigned int extra = 0;
249 __le32 packet_length;
252 /* For tx_length_quirk, put packet length at start of packet */
253 if (ep->chip->tx_length_quirk)
254 extra = sizeof(packet_length);
256 for (i = 0; i < ctx->packets; ++i) {
261 counts = snd_usb_endpoint_next_packet_size(ep, ctx, i);
262 length = counts * ep->stride; /* number of silent bytes */
263 offset = offs * ep->stride + extra * i;
264 urb->iso_frame_desc[i].offset = offset;
265 urb->iso_frame_desc[i].length = length + extra;
267 packet_length = cpu_to_le32(length);
268 memcpy(urb->transfer_buffer + offset,
269 &packet_length, sizeof(packet_length));
271 memset(urb->transfer_buffer + offset + extra,
272 ep->silence_value, length);
276 urb->number_of_packets = ctx->packets;
277 urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra;
281 * Prepare a PLAYBACK urb for submission to the bus.
283 static void prepare_outbound_urb(struct snd_usb_endpoint *ep,
284 struct snd_urb_ctx *ctx)
286 struct urb *urb = ctx->urb;
287 unsigned char *cp = urb->transfer_buffer;
288 struct snd_usb_substream *data_subs;
290 urb->dev = ep->chip->dev; /* we need to set this at each time */
293 case SND_USB_ENDPOINT_TYPE_DATA:
294 data_subs = READ_ONCE(ep->data_subs);
295 if (data_subs && ep->prepare_data_urb)
296 ep->prepare_data_urb(data_subs, urb);
297 else /* no data provider, so send silence */
298 prepare_silent_urb(ep, ctx);
301 case SND_USB_ENDPOINT_TYPE_SYNC:
302 if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) {
304 * fill the length and offset of each urb descriptor.
305 * the fixed 12.13 frequency is passed as 16.16 through the pipe.
307 urb->iso_frame_desc[0].length = 4;
308 urb->iso_frame_desc[0].offset = 0;
310 cp[1] = ep->freqn >> 8;
311 cp[2] = ep->freqn >> 16;
312 cp[3] = ep->freqn >> 24;
315 * fill the length and offset of each urb descriptor.
316 * the fixed 10.14 frequency is passed through the pipe.
318 urb->iso_frame_desc[0].length = 3;
319 urb->iso_frame_desc[0].offset = 0;
320 cp[0] = ep->freqn >> 2;
321 cp[1] = ep->freqn >> 10;
322 cp[2] = ep->freqn >> 18;
330 * Prepare a CAPTURE or SYNC urb for submission to the bus.
332 static inline void prepare_inbound_urb(struct snd_usb_endpoint *ep,
333 struct snd_urb_ctx *urb_ctx)
336 struct urb *urb = urb_ctx->urb;
338 urb->dev = ep->chip->dev; /* we need to set this at each time */
341 case SND_USB_ENDPOINT_TYPE_DATA:
343 for (i = 0; i < urb_ctx->packets; i++) {
344 urb->iso_frame_desc[i].offset = offs;
345 urb->iso_frame_desc[i].length = ep->curpacksize;
346 offs += ep->curpacksize;
349 urb->transfer_buffer_length = offs;
350 urb->number_of_packets = urb_ctx->packets;
353 case SND_USB_ENDPOINT_TYPE_SYNC:
354 urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize);
355 urb->iso_frame_desc[0].offset = 0;
360 /* notify an error as XRUN to the assigned PCM data substream */
361 static void notify_xrun(struct snd_usb_endpoint *ep)
363 struct snd_usb_substream *data_subs;
365 data_subs = READ_ONCE(ep->data_subs);
366 if (data_subs && data_subs->pcm_substream)
367 snd_pcm_stop_xrun(data_subs->pcm_substream);
370 static struct snd_usb_packet_info *
371 next_packet_fifo_enqueue(struct snd_usb_endpoint *ep)
373 struct snd_usb_packet_info *p;
375 p = ep->next_packet + (ep->next_packet_head + ep->next_packet_queued) %
376 ARRAY_SIZE(ep->next_packet);
377 ep->next_packet_queued++;
381 static struct snd_usb_packet_info *
382 next_packet_fifo_dequeue(struct snd_usb_endpoint *ep)
384 struct snd_usb_packet_info *p;
386 p = ep->next_packet + ep->next_packet_head;
387 ep->next_packet_head++;
388 ep->next_packet_head %= ARRAY_SIZE(ep->next_packet);
389 ep->next_packet_queued--;
394 * Send output urbs that have been prepared previously. URBs are dequeued
395 * from ep->ready_playback_urbs and in case there aren't any available
396 * or there are no packets that have been prepared, this function does
399 * The reason why the functionality of sending and preparing URBs is separated
400 * is that host controllers don't guarantee the order in which they return
401 * inbound and outbound packets to their submitters.
403 * This function is only used for implicit feedback endpoints. For endpoints
404 * driven by dedicated sync endpoints, URBs are immediately re-submitted
405 * from their completion handler.
407 static void queue_pending_output_urbs(struct snd_usb_endpoint *ep)
409 while (ep_state_running(ep)) {
412 struct snd_usb_packet_info *packet;
413 struct snd_urb_ctx *ctx = NULL;
416 spin_lock_irqsave(&ep->lock, flags);
417 if (ep->next_packet_queued > 0 &&
418 !list_empty(&ep->ready_playback_urbs)) {
419 /* take URB out of FIFO */
420 ctx = list_first_entry(&ep->ready_playback_urbs,
421 struct snd_urb_ctx, ready_list);
422 list_del_init(&ctx->ready_list);
424 packet = next_packet_fifo_dequeue(ep);
426 spin_unlock_irqrestore(&ep->lock, flags);
431 /* copy over the length information */
432 for (i = 0; i < packet->packets; i++)
433 ctx->packet_size[i] = packet->packet_size[i];
435 /* call the data handler to fill in playback data */
436 prepare_outbound_urb(ep, ctx);
438 err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
440 usb_audio_err(ep->chip,
441 "Unable to submit urb #%d: %d at %s\n",
442 ctx->index, err, __func__);
447 set_bit(ctx->index, &ep->active_mask);
452 * complete callback for urbs
454 static void snd_complete_urb(struct urb *urb)
456 struct snd_urb_ctx *ctx = urb->context;
457 struct snd_usb_endpoint *ep = ctx->ep;
461 if (unlikely(urb->status == -ENOENT || /* unlinked */
462 urb->status == -ENODEV || /* device removed */
463 urb->status == -ECONNRESET || /* unlinked */
464 urb->status == -ESHUTDOWN)) /* device disabled */
466 /* device disconnected */
467 if (unlikely(atomic_read(&ep->chip->shutdown)))
470 if (unlikely(!ep_state_running(ep)))
473 if (usb_pipeout(ep->pipe)) {
474 retire_outbound_urb(ep, ctx);
475 /* can be stopped during retire callback */
476 if (unlikely(!ep_state_running(ep)))
479 if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
480 spin_lock_irqsave(&ep->lock, flags);
481 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
482 clear_bit(ctx->index, &ep->active_mask);
483 spin_unlock_irqrestore(&ep->lock, flags);
484 queue_pending_output_urbs(ep);
488 prepare_outbound_urb(ep, ctx);
489 /* can be stopped during prepare callback */
490 if (unlikely(!ep_state_running(ep)))
493 retire_inbound_urb(ep, ctx);
494 /* can be stopped during retire callback */
495 if (unlikely(!ep_state_running(ep)))
498 prepare_inbound_urb(ep, ctx);
501 err = usb_submit_urb(urb, GFP_ATOMIC);
505 usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
509 clear_bit(ctx->index, &ep->active_mask);
513 * Find or create a refcount object for the given interface
515 * The objects are released altogether in snd_usb_endpoint_free_all()
517 static struct snd_usb_iface_ref *
518 iface_ref_find(struct snd_usb_audio *chip, int iface)
520 struct snd_usb_iface_ref *ip;
522 list_for_each_entry(ip, &chip->iface_ref_list, list)
523 if (ip->iface == iface)
526 ip = kzalloc(sizeof(*ip), GFP_KERNEL);
530 list_add_tail(&ip->list, &chip->iface_ref_list);
535 * Get the existing endpoint object corresponding EP
536 * Returns NULL if not present.
538 struct snd_usb_endpoint *
539 snd_usb_get_endpoint(struct snd_usb_audio *chip, int ep_num)
541 struct snd_usb_endpoint *ep;
543 list_for_each_entry(ep, &chip->ep_list, list) {
544 if (ep->ep_num == ep_num)
551 #define ep_type_name(type) \
552 (type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync")
555 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
558 * @ep_num: The number of the endpoint to use
559 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
561 * If the requested endpoint has not been added to the given chip before,
562 * a new instance is created.
564 * Returns zero on success or a negative error code.
566 * New endpoints will be added to chip->ep_list and freed by
567 * calling snd_usb_endpoint_free_all().
569 * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
570 * bNumEndpoints > 1 beforehand.
572 int snd_usb_add_endpoint(struct snd_usb_audio *chip, int ep_num, int type)
574 struct snd_usb_endpoint *ep;
577 ep = snd_usb_get_endpoint(chip, ep_num);
581 usb_audio_dbg(chip, "Creating new %s endpoint #%x\n",
584 ep = kzalloc(sizeof(*ep), GFP_KERNEL);
589 spin_lock_init(&ep->lock);
592 INIT_LIST_HEAD(&ep->ready_playback_urbs);
594 is_playback = ((ep_num & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT);
595 ep_num &= USB_ENDPOINT_NUMBER_MASK;
597 ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
599 ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);
601 list_add_tail(&ep->list, &chip->ep_list);
605 /* Set up syncinterval and maxsyncsize for a sync EP */
606 static void endpoint_set_syncinterval(struct snd_usb_audio *chip,
607 struct snd_usb_endpoint *ep)
609 struct usb_host_interface *alts;
610 struct usb_endpoint_descriptor *desc;
612 alts = snd_usb_get_host_interface(chip, ep->iface, ep->altsetting);
616 desc = get_endpoint(alts, ep->ep_idx);
617 if (desc->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
618 desc->bRefresh >= 1 && desc->bRefresh <= 9)
619 ep->syncinterval = desc->bRefresh;
620 else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
621 ep->syncinterval = 1;
622 else if (desc->bInterval >= 1 && desc->bInterval <= 16)
623 ep->syncinterval = desc->bInterval - 1;
625 ep->syncinterval = 3;
627 ep->syncmaxsize = le16_to_cpu(desc->wMaxPacketSize);
630 static bool endpoint_compatible(struct snd_usb_endpoint *ep,
631 const struct audioformat *fp,
632 const struct snd_pcm_hw_params *params)
636 if (ep->cur_audiofmt != fp)
638 if (ep->cur_rate != params_rate(params) ||
639 ep->cur_format != params_format(params) ||
640 ep->cur_period_frames != params_period_size(params) ||
641 ep->cur_buffer_periods != params_periods(params))
647 * Check whether the given fp and hw params are compatbile with the current
648 * setup of the target EP for implicit feedback sync
650 bool snd_usb_endpoint_compatible(struct snd_usb_audio *chip,
651 struct snd_usb_endpoint *ep,
652 const struct audioformat *fp,
653 const struct snd_pcm_hw_params *params)
657 mutex_lock(&chip->mutex);
658 ret = endpoint_compatible(ep, fp, params);
659 mutex_unlock(&chip->mutex);
664 * snd_usb_endpoint_open: Open the endpoint
666 * Called from hw_params to assign the endpoint to the substream.
667 * It's reference-counted, and only the first opener is allowed to set up
668 * arbitrary parameters. The later opener must be compatible with the
669 * former opened parameters.
670 * The endpoint needs to be closed via snd_usb_endpoint_close() later.
672 * Note that this function doesn't configure the endpoint. The substream
673 * needs to set it up later via snd_usb_endpoint_configure().
675 struct snd_usb_endpoint *
676 snd_usb_endpoint_open(struct snd_usb_audio *chip,
677 const struct audioformat *fp,
678 const struct snd_pcm_hw_params *params,
681 struct snd_usb_endpoint *ep;
682 int ep_num = is_sync_ep ? fp->sync_ep : fp->endpoint;
684 mutex_lock(&chip->mutex);
685 ep = snd_usb_get_endpoint(chip, ep_num);
687 usb_audio_err(chip, "Cannot find EP 0x%x to open\n", ep_num);
693 ep->iface = fp->sync_iface;
694 ep->altsetting = fp->sync_altsetting;
695 ep->ep_idx = fp->sync_ep_idx;
697 ep->iface = fp->iface;
698 ep->altsetting = fp->altsetting;
699 ep->ep_idx = fp->ep_idx;
701 usb_audio_dbg(chip, "Open EP 0x%x, iface=%d:%d, idx=%d\n",
702 ep_num, ep->iface, ep->altsetting, ep->ep_idx);
704 ep->iface_ref = iface_ref_find(chip, ep->iface);
705 if (!ep->iface_ref) {
710 ep->cur_audiofmt = fp;
711 ep->cur_channels = fp->channels;
712 ep->cur_rate = params_rate(params);
713 ep->cur_format = params_format(params);
714 ep->cur_frame_bytes = snd_pcm_format_physical_width(ep->cur_format) *
715 ep->cur_channels / 8;
716 ep->cur_period_frames = params_period_size(params);
717 ep->cur_period_bytes = ep->cur_period_frames * ep->cur_frame_bytes;
718 ep->cur_buffer_periods = params_periods(params);
720 if (ep->type == SND_USB_ENDPOINT_TYPE_SYNC)
721 endpoint_set_syncinterval(chip, ep);
723 ep->implicit_fb_sync = fp->implicit_fb;
724 ep->need_setup = true;
726 usb_audio_dbg(chip, " channels=%d, rate=%d, format=%s, period_bytes=%d, periods=%d, implicit_fb=%d\n",
727 ep->cur_channels, ep->cur_rate,
728 snd_pcm_format_name(ep->cur_format),
729 ep->cur_period_bytes, ep->cur_buffer_periods,
730 ep->implicit_fb_sync);
733 if (WARN_ON(!ep->iface_ref)) {
738 if (!endpoint_compatible(ep, fp, params)) {
739 usb_audio_err(chip, "Incompatible EP setup for 0x%x\n",
745 usb_audio_dbg(chip, "Reopened EP 0x%x (count %d)\n",
749 if (!ep->iface_ref->opened++)
750 ep->iface_ref->need_setup = true;
755 mutex_unlock(&chip->mutex);
760 * snd_usb_endpoint_set_sync: Link data and sync endpoints
762 * Pass NULL to sync_ep to unlink again
764 void snd_usb_endpoint_set_sync(struct snd_usb_audio *chip,
765 struct snd_usb_endpoint *data_ep,
766 struct snd_usb_endpoint *sync_ep)
768 data_ep->sync_source = sync_ep;
772 * Set data endpoint callbacks and the assigned data stream
774 * Called at PCM trigger and cleanups.
775 * Pass NULL to deactivate each callback.
777 void snd_usb_endpoint_set_callback(struct snd_usb_endpoint *ep,
778 void (*prepare)(struct snd_usb_substream *subs,
780 void (*retire)(struct snd_usb_substream *subs,
782 struct snd_usb_substream *data_subs)
784 ep->prepare_data_urb = prepare;
785 ep->retire_data_urb = retire;
786 WRITE_ONCE(ep->data_subs, data_subs);
789 static int endpoint_set_interface(struct snd_usb_audio *chip,
790 struct snd_usb_endpoint *ep,
793 int altset = set ? ep->altsetting : 0;
796 usb_audio_dbg(chip, "Setting usb interface %d:%d for EP 0x%x\n",
797 ep->iface, altset, ep->ep_num);
798 err = usb_set_interface(chip->dev, ep->iface, altset);
800 usb_audio_err(chip, "%d:%d: usb_set_interface failed (%d)\n",
801 ep->iface, altset, err);
805 snd_usb_set_interface_quirk(chip);
810 * snd_usb_endpoint_close: Close the endpoint
812 * Unreference the already opened endpoint via snd_usb_endpoint_open().
814 void snd_usb_endpoint_close(struct snd_usb_audio *chip,
815 struct snd_usb_endpoint *ep)
817 mutex_lock(&chip->mutex);
818 usb_audio_dbg(chip, "Closing EP 0x%x (count %d)\n",
819 ep->ep_num, ep->opened);
821 if (!--ep->iface_ref->opened)
822 endpoint_set_interface(chip, ep, false);
827 ep->cur_audiofmt = NULL;
829 ep->iface_ref = NULL;
830 usb_audio_dbg(chip, "EP 0x%x closed\n", ep->ep_num);
832 mutex_unlock(&chip->mutex);
835 /* Prepare for suspening EP, called from the main suspend handler */
836 void snd_usb_endpoint_suspend(struct snd_usb_endpoint *ep)
838 ep->need_setup = true;
840 ep->iface_ref->need_setup = true;
844 * wait until all urbs are processed.
846 static int wait_clear_urbs(struct snd_usb_endpoint *ep)
848 unsigned long end_time = jiffies + msecs_to_jiffies(1000);
851 if (atomic_read(&ep->state) != EP_STATE_STOPPING)
855 alive = bitmap_weight(&ep->active_mask, ep->nurbs);
859 schedule_timeout_uninterruptible(1);
860 } while (time_before(jiffies, end_time));
863 usb_audio_err(ep->chip,
864 "timeout: still %d active urbs on EP #%x\n",
867 if (ep_state_update(ep, EP_STATE_STOPPING, EP_STATE_STOPPED)) {
868 ep->sync_sink = NULL;
869 snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
875 /* sync the pending stop operation;
876 * this function itself doesn't trigger the stop operation
878 void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
887 * This function moves the EP to STOPPING state if it's being RUNNING.
889 static int stop_urbs(struct snd_usb_endpoint *ep, bool force)
893 if (!force && atomic_read(&ep->running))
896 if (!ep_state_update(ep, EP_STATE_RUNNING, EP_STATE_STOPPING))
899 INIT_LIST_HEAD(&ep->ready_playback_urbs);
900 ep->next_packet_head = 0;
901 ep->next_packet_queued = 0;
903 for (i = 0; i < ep->nurbs; i++) {
904 if (test_bit(i, &ep->active_mask)) {
905 if (!test_and_set_bit(i, &ep->unlink_mask)) {
906 struct urb *u = ep->urb[i].urb;
916 * release an endpoint's urbs
918 static int release_urbs(struct snd_usb_endpoint *ep, bool force)
922 /* route incoming urbs to nirvana */
923 snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
925 /* stop and unlink urbs */
926 err = stop_urbs(ep, force);
932 for (i = 0; i < ep->nurbs; i++)
933 release_urb_ctx(&ep->urb[i]);
935 usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
936 ep->syncbuf, ep->sync_dma);
944 * configure a data endpoint
946 static int data_ep_set_params(struct snd_usb_endpoint *ep)
948 struct snd_usb_audio *chip = ep->chip;
949 unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
950 unsigned int max_packs_per_period, urbs_per_period, urb_packs;
951 unsigned int max_urbs, i;
952 const struct audioformat *fmt = ep->cur_audiofmt;
953 int frame_bits = ep->cur_frame_bytes * 8;
954 int tx_length_quirk = (chip->tx_length_quirk &&
955 usb_pipeout(ep->pipe));
957 usb_audio_dbg(chip, "Setting params for data EP 0x%x, pipe 0x%x\n",
958 ep->ep_num, ep->pipe);
960 if (ep->cur_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
962 * When operating in DSD DOP mode, the size of a sample frame
963 * in hardware differs from the actual physical format width
964 * because we need to make room for the DOP markers.
966 frame_bits += ep->cur_channels << 3;
969 ep->datainterval = fmt->datainterval;
970 ep->stride = frame_bits >> 3;
972 switch (ep->cur_format) {
973 case SNDRV_PCM_FORMAT_U8:
974 ep->silence_value = 0x80;
976 case SNDRV_PCM_FORMAT_DSD_U8:
977 case SNDRV_PCM_FORMAT_DSD_U16_LE:
978 case SNDRV_PCM_FORMAT_DSD_U32_LE:
979 case SNDRV_PCM_FORMAT_DSD_U16_BE:
980 case SNDRV_PCM_FORMAT_DSD_U32_BE:
981 ep->silence_value = 0x69;
984 ep->silence_value = 0;
987 /* assume max. frequency is 50% higher than nominal */
988 ep->freqmax = ep->freqn + (ep->freqn >> 1);
989 /* Round up freqmax to nearest integer in order to calculate maximum
990 * packet size, which must represent a whole number of frames.
991 * This is accomplished by adding 0x0.ffff before converting the
992 * Q16.16 format into integer.
993 * In order to accurately calculate the maximum packet size when
994 * the data interval is more than 1 (i.e. ep->datainterval > 0),
995 * multiply by the data interval prior to rounding. For instance,
996 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
997 * frames with a data interval of 1, but 11 (10.25) frames with a
998 * data interval of 2.
999 * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
1000 * maximum datainterval value of 3, at USB full speed, higher for
1001 * USB high speed, noting that ep->freqmax is in units of
1002 * frames per packet in Q16.16 format.)
1004 maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
1006 if (tx_length_quirk)
1007 maxsize += sizeof(__le32); /* Space for length descriptor */
1008 /* but wMaxPacketSize might reduce this */
1009 if (ep->maxpacksize && ep->maxpacksize < maxsize) {
1010 /* whatever fits into a max. size packet */
1011 unsigned int data_maxsize = maxsize = ep->maxpacksize;
1013 if (tx_length_quirk)
1014 /* Need to remove the length descriptor to calc freq */
1015 data_maxsize -= sizeof(__le32);
1016 ep->freqmax = (data_maxsize / (frame_bits >> 3))
1017 << (16 - ep->datainterval);
1021 ep->curpacksize = ep->maxpacksize;
1023 ep->curpacksize = maxsize;
1025 if (snd_usb_get_speed(chip->dev) != USB_SPEED_FULL) {
1026 packs_per_ms = 8 >> ep->datainterval;
1027 max_packs_per_urb = MAX_PACKS_HS;
1030 max_packs_per_urb = MAX_PACKS;
1032 if (ep->sync_source && !ep->implicit_fb_sync)
1033 max_packs_per_urb = min(max_packs_per_urb,
1034 1U << ep->sync_source->syncinterval);
1035 max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);
1038 * Capture endpoints need to use small URBs because there's no way
1039 * to tell in advance where the next period will end, and we don't
1040 * want the next URB to complete much after the period ends.
1042 * Playback endpoints with implicit sync much use the same parameters
1043 * as their corresponding capture endpoint.
1045 if (usb_pipein(ep->pipe) || ep->implicit_fb_sync) {
1047 urb_packs = packs_per_ms;
1049 * Wireless devices can poll at a max rate of once per 4ms.
1050 * For dataintervals less than 5, increase the packet count to
1051 * allow the host controller to use bursting to fill in the
1054 if (snd_usb_get_speed(chip->dev) == USB_SPEED_WIRELESS) {
1055 int interval = ep->datainterval;
1056 while (interval < 5) {
1061 /* make capture URBs <= 1 ms and smaller than a period */
1062 urb_packs = min(max_packs_per_urb, urb_packs);
1063 while (urb_packs > 1 && urb_packs * maxsize >= ep->cur_period_bytes)
1065 ep->nurbs = MAX_URBS;
1068 * Playback endpoints without implicit sync are adjusted so that
1069 * a period fits as evenly as possible in the smallest number of
1070 * URBs. The total number of URBs is adjusted to the size of the
1071 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
1074 /* determine how small a packet can be */
1075 minsize = (ep->freqn >> (16 - ep->datainterval)) *
1077 /* with sync from device, assume it can be 12% lower */
1078 if (ep->sync_source)
1079 minsize -= minsize >> 3;
1080 minsize = max(minsize, 1u);
1082 /* how many packets will contain an entire ALSA period? */
1083 max_packs_per_period = DIV_ROUND_UP(ep->cur_period_bytes, minsize);
1085 /* how many URBs will contain a period? */
1086 urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
1088 /* how many packets are needed in each URB? */
1089 urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);
1091 /* limit the number of frames in a single URB */
1092 ep->max_urb_frames = DIV_ROUND_UP(ep->cur_period_frames,
1095 /* try to use enough URBs to contain an entire ALSA buffer */
1096 max_urbs = min((unsigned) MAX_URBS,
1097 MAX_QUEUE * packs_per_ms / urb_packs);
1098 ep->nurbs = min(max_urbs, urbs_per_period * ep->cur_buffer_periods);
1101 /* allocate and initialize data urbs */
1102 for (i = 0; i < ep->nurbs; i++) {
1103 struct snd_urb_ctx *u = &ep->urb[i];
1106 u->packets = urb_packs;
1107 u->buffer_size = maxsize * u->packets;
1109 if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
1110 u->packets++; /* for transfer delimiter */
1111 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
1115 u->urb->transfer_buffer =
1116 usb_alloc_coherent(chip->dev, u->buffer_size,
1117 GFP_KERNEL, &u->urb->transfer_dma);
1118 if (!u->urb->transfer_buffer)
1120 u->urb->pipe = ep->pipe;
1121 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
1122 u->urb->interval = 1 << ep->datainterval;
1123 u->urb->context = u;
1124 u->urb->complete = snd_complete_urb;
1125 INIT_LIST_HEAD(&u->ready_list);
1131 release_urbs(ep, false);
1136 * configure a sync endpoint
1138 static int sync_ep_set_params(struct snd_usb_endpoint *ep)
1140 struct snd_usb_audio *chip = ep->chip;
1143 usb_audio_dbg(chip, "Setting params for sync EP 0x%x, pipe 0x%x\n",
1144 ep->ep_num, ep->pipe);
1146 ep->syncbuf = usb_alloc_coherent(chip->dev, SYNC_URBS * 4,
1147 GFP_KERNEL, &ep->sync_dma);
1151 for (i = 0; i < SYNC_URBS; i++) {
1152 struct snd_urb_ctx *u = &ep->urb[i];
1156 u->urb = usb_alloc_urb(1, GFP_KERNEL);
1159 u->urb->transfer_buffer = ep->syncbuf + i * 4;
1160 u->urb->transfer_dma = ep->sync_dma + i * 4;
1161 u->urb->transfer_buffer_length = 4;
1162 u->urb->pipe = ep->pipe;
1163 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
1164 u->urb->number_of_packets = 1;
1165 u->urb->interval = 1 << ep->syncinterval;
1166 u->urb->context = u;
1167 u->urb->complete = snd_complete_urb;
1170 ep->nurbs = SYNC_URBS;
1175 release_urbs(ep, false);
1180 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
1182 * Determine the number of URBs to be used on this endpoint.
1183 * An endpoint must be configured before it can be started.
1184 * An endpoint that is already running can not be reconfigured.
1186 static int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
1187 struct snd_usb_endpoint *ep)
1189 const struct audioformat *fmt = ep->cur_audiofmt;
1192 /* release old buffers, if any */
1193 err = release_urbs(ep, false);
1197 ep->datainterval = fmt->datainterval;
1198 ep->maxpacksize = fmt->maxpacksize;
1199 ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
1201 if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL) {
1202 ep->freqn = get_usb_full_speed_rate(ep->cur_rate);
1203 ep->pps = 1000 >> ep->datainterval;
1205 ep->freqn = get_usb_high_speed_rate(ep->cur_rate);
1206 ep->pps = 8000 >> ep->datainterval;
1209 ep->sample_rem = ep->cur_rate % ep->pps;
1210 ep->packsize[0] = ep->cur_rate / ep->pps;
1211 ep->packsize[1] = (ep->cur_rate + (ep->pps - 1)) / ep->pps;
1213 /* calculate the frequency in 16.16 format */
1214 ep->freqm = ep->freqn;
1215 ep->freqshift = INT_MIN;
1220 case SND_USB_ENDPOINT_TYPE_DATA:
1221 err = data_ep_set_params(ep);
1223 case SND_USB_ENDPOINT_TYPE_SYNC:
1224 err = sync_ep_set_params(ep);
1230 usb_audio_dbg(chip, "Set up %d URBS, ret=%d\n", ep->nurbs, err);
1235 /* some unit conversions in runtime */
1236 ep->maxframesize = ep->maxpacksize / ep->cur_frame_bytes;
1237 ep->curframesize = ep->curpacksize / ep->cur_frame_bytes;
1243 * snd_usb_endpoint_configure: Configure the endpoint
1245 * This function sets up the EP to be fully usable state.
1246 * It's called either from hw_params or prepare callback.
1247 * The function checks need_setup flag, and perfoms nothing unless needed,
1248 * so it's safe to call this multiple times.
1250 * This returns zero if unchanged, 1 if the configuration has changed,
1251 * or a negative error code.
1253 int snd_usb_endpoint_configure(struct snd_usb_audio *chip,
1254 struct snd_usb_endpoint *ep)
1259 mutex_lock(&chip->mutex);
1260 if (WARN_ON(!ep->iface_ref))
1262 if (!ep->need_setup)
1265 /* If the interface has been already set up, just set EP parameters */
1266 if (!ep->iface_ref->need_setup) {
1267 /* sample rate setup of UAC1 is per endpoint, and we need
1268 * to update at each EP configuration
1270 if (ep->cur_audiofmt->protocol == UAC_VERSION_1) {
1271 err = snd_usb_init_sample_rate(chip, ep->cur_audiofmt,
1276 err = snd_usb_endpoint_set_params(chip, ep);
1282 /* Need to deselect altsetting at first */
1283 endpoint_set_interface(chip, ep, false);
1285 /* Some UAC1 devices (e.g. Yamaha THR10) need the host interface
1286 * to be set up before parameter setups
1288 iface_first = ep->cur_audiofmt->protocol == UAC_VERSION_1;
1290 err = endpoint_set_interface(chip, ep, true);
1295 err = snd_usb_init_pitch(chip, ep->cur_audiofmt);
1299 err = snd_usb_init_sample_rate(chip, ep->cur_audiofmt, ep->cur_rate);
1303 err = snd_usb_endpoint_set_params(chip, ep);
1307 err = snd_usb_select_mode_quirk(chip, ep->cur_audiofmt);
1311 /* for UAC2/3, enable the interface altset here at last */
1313 err = endpoint_set_interface(chip, ep, true);
1318 ep->iface_ref->need_setup = false;
1321 ep->need_setup = false;
1325 mutex_unlock(&chip->mutex);
1330 * snd_usb_endpoint_start: start an snd_usb_endpoint
1332 * @ep: the endpoint to start
1334 * A call to this function will increment the running count of the endpoint.
1335 * In case it is not already running, the URBs for this endpoint will be
1336 * submitted. Otherwise, this function does nothing.
1338 * Must be balanced to calls of snd_usb_endpoint_stop().
1340 * Returns an error if the URB submission failed, 0 in all other cases.
1342 int snd_usb_endpoint_start(struct snd_usb_endpoint *ep)
1347 if (atomic_read(&ep->chip->shutdown))
1350 if (ep->sync_source)
1351 WRITE_ONCE(ep->sync_source->sync_sink, ep);
1353 usb_audio_dbg(ep->chip, "Starting %s EP 0x%x (running %d)\n",
1354 ep_type_name(ep->type), ep->ep_num,
1355 atomic_read(&ep->running));
1357 /* already running? */
1358 if (atomic_inc_return(&ep->running) != 1)
1361 ep->active_mask = 0;
1362 ep->unlink_mask = 0;
1364 ep->sample_accum = 0;
1366 snd_usb_endpoint_start_quirk(ep);
1369 * If this endpoint has a data endpoint as implicit feedback source,
1370 * don't start the urbs here. Instead, mark them all as available,
1371 * wait for the record urbs to return and queue the playback urbs
1372 * from that context.
1375 if (!ep_state_update(ep, EP_STATE_STOPPED, EP_STATE_RUNNING))
1378 if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1379 !ep->chip->playback_first) {
1380 for (i = 0; i < ep->nurbs; i++) {
1381 struct snd_urb_ctx *ctx = ep->urb + i;
1382 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
1385 usb_audio_dbg(ep->chip, "No URB submission due to implicit fb sync\n");
1389 for (i = 0; i < ep->nurbs; i++) {
1390 struct urb *urb = ep->urb[i].urb;
1392 if (snd_BUG_ON(!urb))
1395 if (usb_pipeout(ep->pipe)) {
1396 prepare_outbound_urb(ep, urb->context);
1398 prepare_inbound_urb(ep, urb->context);
1401 err = usb_submit_urb(urb, GFP_ATOMIC);
1403 usb_audio_err(ep->chip,
1404 "cannot submit urb %d, error %d: %s\n",
1405 i, err, usb_error_string(err));
1408 set_bit(i, &ep->active_mask);
1411 usb_audio_dbg(ep->chip, "%d URBs submitted for EP 0x%x\n",
1412 ep->nurbs, ep->ep_num);
1416 snd_usb_endpoint_stop(ep);
1421 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
1423 * @ep: the endpoint to stop (may be NULL)
1425 * A call to this function will decrement the running count of the endpoint.
1426 * In case the last user has requested the endpoint stop, the URBs will
1427 * actually be deactivated.
1429 * Must be balanced to calls of snd_usb_endpoint_start().
1431 * The caller needs to synchronize the pending stop operation via
1432 * snd_usb_endpoint_sync_pending_stop().
1434 void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep)
1439 usb_audio_dbg(ep->chip, "Stopping %s EP 0x%x (running %d)\n",
1440 ep_type_name(ep->type), ep->ep_num,
1441 atomic_read(&ep->running));
1443 if (snd_BUG_ON(!atomic_read(&ep->running)))
1446 if (!atomic_dec_return(&ep->running)) {
1447 if (ep->sync_source)
1448 WRITE_ONCE(ep->sync_source->sync_sink, NULL);
1449 stop_urbs(ep, false);
1454 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
1456 * @ep: the endpoint to release
1458 * This function does not care for the endpoint's running count but will tear
1459 * down all the streaming URBs immediately.
1461 void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
1463 release_urbs(ep, true);
1467 * snd_usb_endpoint_free_all: Free the resources of an snd_usb_endpoint
1470 * This free all endpoints and those resources
1472 void snd_usb_endpoint_free_all(struct snd_usb_audio *chip)
1474 struct snd_usb_endpoint *ep, *en;
1475 struct snd_usb_iface_ref *ip, *in;
1477 list_for_each_entry_safe(ep, en, &chip->ep_list, list)
1480 list_for_each_entry_safe(ip, in, &chip->iface_ref_list, list)
1485 * snd_usb_handle_sync_urb: parse an USB sync packet
1487 * @ep: the endpoint to handle the packet
1488 * @sender: the sending endpoint
1489 * @urb: the received packet
1491 * This function is called from the context of an endpoint that received
1492 * the packet and is used to let another endpoint object handle the payload.
1494 static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
1495 struct snd_usb_endpoint *sender,
1496 const struct urb *urb)
1500 unsigned long flags;
1502 snd_BUG_ON(ep == sender);
1505 * In case the endpoint is operating in implicit feedback mode, prepare
1506 * a new outbound URB that has the same layout as the received packet
1507 * and add it to the list of pending urbs. queue_pending_output_urbs()
1508 * will take care of them later.
1510 if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1511 atomic_read(&ep->running)) {
1513 /* implicit feedback case */
1515 struct snd_urb_ctx *in_ctx;
1516 struct snd_usb_packet_info *out_packet;
1518 in_ctx = urb->context;
1520 /* Count overall packet size */
1521 for (i = 0; i < in_ctx->packets; i++)
1522 if (urb->iso_frame_desc[i].status == 0)
1523 bytes += urb->iso_frame_desc[i].actual_length;
1526 * skip empty packets. At least M-Audio's Fast Track Ultra stops
1527 * streaming once it received a 0-byte OUT URB
1532 spin_lock_irqsave(&ep->lock, flags);
1533 if (ep->next_packet_queued >= ARRAY_SIZE(ep->next_packet)) {
1534 spin_unlock_irqrestore(&ep->lock, flags);
1535 usb_audio_err(ep->chip,
1536 "next package FIFO overflow EP 0x%x\n",
1542 out_packet = next_packet_fifo_enqueue(ep);
1545 * Iterate through the inbound packet and prepare the lengths
1546 * for the output packet. The OUT packet we are about to send
1547 * will have the same amount of payload bytes per stride as the
1548 * IN packet we just received. Since the actual size is scaled
1549 * by the stride, use the sender stride to calculate the length
1550 * in case the number of channels differ between the implicitly
1551 * fed-back endpoint and the synchronizing endpoint.
1554 out_packet->packets = in_ctx->packets;
1555 for (i = 0; i < in_ctx->packets; i++) {
1556 if (urb->iso_frame_desc[i].status == 0)
1557 out_packet->packet_size[i] =
1558 urb->iso_frame_desc[i].actual_length / sender->stride;
1560 out_packet->packet_size[i] = 0;
1563 spin_unlock_irqrestore(&ep->lock, flags);
1564 queue_pending_output_urbs(ep);
1570 * process after playback sync complete
1572 * Full speed devices report feedback values in 10.14 format as samples
1573 * per frame, high speed devices in 16.16 format as samples per
1576 * Because the Audio Class 1 spec was written before USB 2.0, many high
1577 * speed devices use a wrong interpretation, some others use an
1578 * entirely different format.
1580 * Therefore, we cannot predict what format any particular device uses
1581 * and must detect it automatically.
1584 if (urb->iso_frame_desc[0].status != 0 ||
1585 urb->iso_frame_desc[0].actual_length < 3)
1588 f = le32_to_cpup(urb->transfer_buffer);
1589 if (urb->iso_frame_desc[0].actual_length == 3)
1597 if (unlikely(sender->tenor_fb_quirk)) {
1599 * Devices based on Tenor 8802 chipsets (TEAC UD-H01
1600 * and others) sometimes change the feedback value
1603 if (f < ep->freqn - 0x8000)
1605 else if (f > ep->freqn + 0x8000)
1607 } else if (unlikely(ep->freqshift == INT_MIN)) {
1609 * The first time we see a feedback value, determine its format
1610 * by shifting it left or right until it matches the nominal
1611 * frequency value. This assumes that the feedback does not
1612 * differ from the nominal value more than +50% or -25%.
1615 while (f < ep->freqn - ep->freqn / 4) {
1619 while (f > ep->freqn + ep->freqn / 2) {
1623 ep->freqshift = shift;
1624 } else if (ep->freqshift >= 0)
1625 f <<= ep->freqshift;
1627 f >>= -ep->freqshift;
1629 if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {
1631 * If the frequency looks valid, set it.
1632 * This value is referred to in prepare_playback_urb().
1634 spin_lock_irqsave(&ep->lock, flags);
1636 spin_unlock_irqrestore(&ep->lock, flags);
1639 * Out of range; maybe the shift value is wrong.
1640 * Reset it so that we autodetect again the next time.
1642 ep->freqshift = INT_MIN;