2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 #include <linux/gfp.h>
19 #include <linux/init.h>
20 #include <linux/ratelimit.h>
21 #include <linux/usb.h>
22 #include <linux/usb/audio.h>
23 #include <linux/slab.h>
25 #include <sound/core.h>
26 #include <sound/pcm.h>
27 #include <sound/pcm_params.h>
36 #define EP_FLAG_RUNNING 1
37 #define EP_FLAG_STOPPING 2
40 * snd_usb_endpoint is a model that abstracts everything related to an
41 * USB endpoint and its streaming.
43 * There are functions to activate and deactivate the streaming URBs and
44 * optional callbacks to let the pcm logic handle the actual content of the
45 * packets for playback and record. Thus, the bus streaming and the audio
46 * handlers are fully decoupled.
48 * There are two different types of endpoints in audio applications.
50 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both
51 * inbound and outbound traffic.
53 * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and
54 * expect the payload to carry Q10.14 / Q16.16 formatted sync information
57 * Each endpoint has to be configured prior to being used by calling
58 * snd_usb_endpoint_set_params().
60 * The model incorporates a reference counting, so that multiple users
61 * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and
62 * only the first user will effectively start the URBs, and only the last
63 * one to stop it will tear the URBs down again.
67 * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
68 * this will overflow at approx 524 kHz
70 static inline unsigned get_usb_full_speed_rate(unsigned int rate)
72 return ((rate << 13) + 62) / 125;
76 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
77 * this will overflow at approx 4 MHz
79 static inline unsigned get_usb_high_speed_rate(unsigned int rate)
81 return ((rate << 10) + 62) / 125;
87 static void release_urb_ctx(struct snd_urb_ctx *u)
90 usb_free_coherent(u->ep->chip->dev, u->buffer_size,
91 u->urb->transfer_buffer,
92 u->urb->transfer_dma);
97 static const char *usb_error_string(int err)
103 return "endpoint not enabled";
105 return "endpoint stalled";
107 return "not enough bandwidth";
109 return "device disabled";
111 return "device suspended";
116 return "internal error";
118 return "unknown error";
123 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type
125 * @ep: The snd_usb_endpoint
127 * Determine whether an endpoint is driven by an implicit feedback
128 * data endpoint source.
130 int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep)
132 return ep->sync_master &&
133 ep->sync_master->type == SND_USB_ENDPOINT_TYPE_DATA &&
134 ep->type == SND_USB_ENDPOINT_TYPE_DATA &&
135 usb_pipeout(ep->pipe);
139 * For streaming based on information derived from sync endpoints,
140 * prepare_outbound_urb_sizes() will call next_packet_size() to
141 * determine the number of samples to be sent in the next packet.
143 * For implicit feedback, next_packet_size() is unused.
145 int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep)
151 return ep->maxframesize;
153 spin_lock_irqsave(&ep->lock, flags);
154 ep->phase = (ep->phase & 0xffff)
155 + (ep->freqm << ep->datainterval);
156 ret = min(ep->phase >> 16, ep->maxframesize);
157 spin_unlock_irqrestore(&ep->lock, flags);
162 static void retire_outbound_urb(struct snd_usb_endpoint *ep,
163 struct snd_urb_ctx *urb_ctx)
165 if (ep->retire_data_urb)
166 ep->retire_data_urb(ep->data_subs, urb_ctx->urb);
169 static void retire_inbound_urb(struct snd_usb_endpoint *ep,
170 struct snd_urb_ctx *urb_ctx)
172 struct urb *urb = urb_ctx->urb;
174 if (unlikely(ep->skip_packets > 0)) {
180 snd_usb_handle_sync_urb(ep->sync_slave, ep, urb);
182 if (ep->retire_data_urb)
183 ep->retire_data_urb(ep->data_subs, urb);
186 static void prepare_silent_urb(struct snd_usb_endpoint *ep,
187 struct snd_urb_ctx *ctx)
189 struct urb *urb = ctx->urb;
190 unsigned int offs = 0;
191 unsigned int extra = 0;
192 __le32 packet_length;
195 /* For tx_length_quirk, put packet length at start of packet */
196 if (ep->chip->tx_length_quirk)
197 extra = sizeof(packet_length);
199 for (i = 0; i < ctx->packets; ++i) {
204 if (ctx->packet_size[i])
205 counts = ctx->packet_size[i];
207 counts = snd_usb_endpoint_next_packet_size(ep);
209 length = counts * ep->stride; /* number of silent bytes */
210 offset = offs * ep->stride + extra * i;
211 urb->iso_frame_desc[i].offset = offset;
212 urb->iso_frame_desc[i].length = length + extra;
214 packet_length = cpu_to_le32(length);
215 memcpy(urb->transfer_buffer + offset,
216 &packet_length, sizeof(packet_length));
218 memset(urb->transfer_buffer + offset + extra,
219 ep->silence_value, length);
223 urb->number_of_packets = ctx->packets;
224 urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra;
228 * Prepare a PLAYBACK urb for submission to the bus.
230 static void prepare_outbound_urb(struct snd_usb_endpoint *ep,
231 struct snd_urb_ctx *ctx)
233 struct urb *urb = ctx->urb;
234 unsigned char *cp = urb->transfer_buffer;
236 urb->dev = ep->chip->dev; /* we need to set this at each time */
239 case SND_USB_ENDPOINT_TYPE_DATA:
240 if (ep->prepare_data_urb) {
241 ep->prepare_data_urb(ep->data_subs, urb);
243 /* no data provider, so send silence */
244 prepare_silent_urb(ep, ctx);
248 case SND_USB_ENDPOINT_TYPE_SYNC:
249 if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) {
251 * fill the length and offset of each urb descriptor.
252 * the fixed 12.13 frequency is passed as 16.16 through the pipe.
254 urb->iso_frame_desc[0].length = 4;
255 urb->iso_frame_desc[0].offset = 0;
257 cp[1] = ep->freqn >> 8;
258 cp[2] = ep->freqn >> 16;
259 cp[3] = ep->freqn >> 24;
262 * fill the length and offset of each urb descriptor.
263 * the fixed 10.14 frequency is passed through the pipe.
265 urb->iso_frame_desc[0].length = 3;
266 urb->iso_frame_desc[0].offset = 0;
267 cp[0] = ep->freqn >> 2;
268 cp[1] = ep->freqn >> 10;
269 cp[2] = ep->freqn >> 18;
277 * Prepare a CAPTURE or SYNC urb for submission to the bus.
279 static inline void prepare_inbound_urb(struct snd_usb_endpoint *ep,
280 struct snd_urb_ctx *urb_ctx)
283 struct urb *urb = urb_ctx->urb;
285 urb->dev = ep->chip->dev; /* we need to set this at each time */
288 case SND_USB_ENDPOINT_TYPE_DATA:
290 for (i = 0; i < urb_ctx->packets; i++) {
291 urb->iso_frame_desc[i].offset = offs;
292 urb->iso_frame_desc[i].length = ep->curpacksize;
293 offs += ep->curpacksize;
296 urb->transfer_buffer_length = offs;
297 urb->number_of_packets = urb_ctx->packets;
300 case SND_USB_ENDPOINT_TYPE_SYNC:
301 urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize);
302 urb->iso_frame_desc[0].offset = 0;
308 * Send output urbs that have been prepared previously. URBs are dequeued
309 * from ep->ready_playback_urbs and in case there there aren't any available
310 * or there are no packets that have been prepared, this function does
313 * The reason why the functionality of sending and preparing URBs is separated
314 * is that host controllers don't guarantee the order in which they return
315 * inbound and outbound packets to their submitters.
317 * This function is only used for implicit feedback endpoints. For endpoints
318 * driven by dedicated sync endpoints, URBs are immediately re-submitted
319 * from their completion handler.
321 static void queue_pending_output_urbs(struct snd_usb_endpoint *ep)
323 while (test_bit(EP_FLAG_RUNNING, &ep->flags)) {
326 struct snd_usb_packet_info *uninitialized_var(packet);
327 struct snd_urb_ctx *ctx = NULL;
330 spin_lock_irqsave(&ep->lock, flags);
331 if (ep->next_packet_read_pos != ep->next_packet_write_pos) {
332 packet = ep->next_packet + ep->next_packet_read_pos;
333 ep->next_packet_read_pos++;
334 ep->next_packet_read_pos %= MAX_URBS;
336 /* take URB out of FIFO */
337 if (!list_empty(&ep->ready_playback_urbs)) {
338 ctx = list_first_entry(&ep->ready_playback_urbs,
339 struct snd_urb_ctx, ready_list);
340 list_del_init(&ctx->ready_list);
343 spin_unlock_irqrestore(&ep->lock, flags);
348 /* copy over the length information */
349 for (i = 0; i < packet->packets; i++)
350 ctx->packet_size[i] = packet->packet_size[i];
352 /* call the data handler to fill in playback data */
353 prepare_outbound_urb(ep, ctx);
355 err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
357 usb_audio_err(ep->chip,
358 "Unable to submit urb #%d: %d (urb %p)\n",
359 ctx->index, err, ctx->urb);
361 set_bit(ctx->index, &ep->active_mask);
366 * complete callback for urbs
368 static void snd_complete_urb(struct urb *urb)
370 struct snd_urb_ctx *ctx = urb->context;
371 struct snd_usb_endpoint *ep = ctx->ep;
372 struct snd_pcm_substream *substream;
376 if (unlikely(urb->status == -ENOENT || /* unlinked */
377 urb->status == -ENODEV || /* device removed */
378 urb->status == -ECONNRESET || /* unlinked */
379 urb->status == -ESHUTDOWN)) /* device disabled */
381 /* device disconnected */
382 if (unlikely(atomic_read(&ep->chip->shutdown)))
385 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
388 if (usb_pipeout(ep->pipe)) {
389 retire_outbound_urb(ep, ctx);
390 /* can be stopped during retire callback */
391 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
394 if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
395 spin_lock_irqsave(&ep->lock, flags);
396 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
397 spin_unlock_irqrestore(&ep->lock, flags);
398 queue_pending_output_urbs(ep);
403 prepare_outbound_urb(ep, ctx);
404 /* can be stopped during prepare callback */
405 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
408 retire_inbound_urb(ep, ctx);
409 /* can be stopped during retire callback */
410 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
413 prepare_inbound_urb(ep, ctx);
416 err = usb_submit_urb(urb, GFP_ATOMIC);
420 usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
421 if (ep->data_subs && ep->data_subs->pcm_substream) {
422 substream = ep->data_subs->pcm_substream;
423 snd_pcm_stop_xrun(substream);
427 clear_bit(ctx->index, &ep->active_mask);
431 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
434 * @alts: The USB host interface
435 * @ep_num: The number of the endpoint to use
436 * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE
437 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
439 * If the requested endpoint has not been added to the given chip before,
440 * a new instance is created. Otherwise, a pointer to the previoulsy
441 * created instance is returned. In case of any error, NULL is returned.
443 * New endpoints will be added to chip->ep_list and must be freed by
444 * calling snd_usb_endpoint_free().
446 * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
447 * bNumEndpoints > 1 beforehand.
449 struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip,
450 struct usb_host_interface *alts,
451 int ep_num, int direction, int type)
453 struct snd_usb_endpoint *ep;
454 int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK;
459 mutex_lock(&chip->mutex);
461 list_for_each_entry(ep, &chip->ep_list, list) {
462 if (ep->ep_num == ep_num &&
463 ep->iface == alts->desc.bInterfaceNumber &&
464 ep->altsetting == alts->desc.bAlternateSetting) {
465 usb_audio_dbg(ep->chip,
466 "Re-using EP %x in iface %d,%d @%p\n",
467 ep_num, ep->iface, ep->altsetting, ep);
472 usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n",
473 is_playback ? "playback" : "capture",
474 type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync",
477 ep = kzalloc(sizeof(*ep), GFP_KERNEL);
482 spin_lock_init(&ep->lock);
485 ep->iface = alts->desc.bInterfaceNumber;
486 ep->altsetting = alts->desc.bAlternateSetting;
487 INIT_LIST_HEAD(&ep->ready_playback_urbs);
488 ep_num &= USB_ENDPOINT_NUMBER_MASK;
491 ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
493 ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);
495 if (type == SND_USB_ENDPOINT_TYPE_SYNC) {
496 if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
497 get_endpoint(alts, 1)->bRefresh >= 1 &&
498 get_endpoint(alts, 1)->bRefresh <= 9)
499 ep->syncinterval = get_endpoint(alts, 1)->bRefresh;
500 else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
501 ep->syncinterval = 1;
502 else if (get_endpoint(alts, 1)->bInterval >= 1 &&
503 get_endpoint(alts, 1)->bInterval <= 16)
504 ep->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
506 ep->syncinterval = 3;
508 ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize);
511 list_add_tail(&ep->list, &chip->ep_list);
514 mutex_unlock(&chip->mutex);
520 * wait until all urbs are processed.
522 static int wait_clear_urbs(struct snd_usb_endpoint *ep)
524 unsigned long end_time = jiffies + msecs_to_jiffies(1000);
528 alive = bitmap_weight(&ep->active_mask, ep->nurbs);
532 schedule_timeout_uninterruptible(1);
533 } while (time_before(jiffies, end_time));
536 usb_audio_err(ep->chip,
537 "timeout: still %d active urbs on EP #%x\n",
539 clear_bit(EP_FLAG_STOPPING, &ep->flags);
541 ep->data_subs = NULL;
542 ep->sync_slave = NULL;
543 ep->retire_data_urb = NULL;
544 ep->prepare_data_urb = NULL;
549 /* sync the pending stop operation;
550 * this function itself doesn't trigger the stop operation
552 void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
554 if (ep && test_bit(EP_FLAG_STOPPING, &ep->flags))
559 * unlink active urbs.
561 static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force)
565 if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */
568 clear_bit(EP_FLAG_RUNNING, &ep->flags);
570 INIT_LIST_HEAD(&ep->ready_playback_urbs);
571 ep->next_packet_read_pos = 0;
572 ep->next_packet_write_pos = 0;
574 for (i = 0; i < ep->nurbs; i++) {
575 if (test_bit(i, &ep->active_mask)) {
576 if (!test_and_set_bit(i, &ep->unlink_mask)) {
577 struct urb *u = ep->urb[i].urb;
587 * release an endpoint's urbs
589 static void release_urbs(struct snd_usb_endpoint *ep, int force)
593 /* route incoming urbs to nirvana */
594 ep->retire_data_urb = NULL;
595 ep->prepare_data_urb = NULL;
598 deactivate_urbs(ep, force);
601 for (i = 0; i < ep->nurbs; i++)
602 release_urb_ctx(&ep->urb[i]);
605 usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
606 ep->syncbuf, ep->sync_dma);
613 * configure a data endpoint
615 static int data_ep_set_params(struct snd_usb_endpoint *ep,
616 snd_pcm_format_t pcm_format,
617 unsigned int channels,
618 unsigned int period_bytes,
619 unsigned int frames_per_period,
620 unsigned int periods_per_buffer,
621 struct audioformat *fmt,
622 struct snd_usb_endpoint *sync_ep)
624 unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
625 unsigned int max_packs_per_period, urbs_per_period, urb_packs;
626 unsigned int max_urbs, i;
627 int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
628 int tx_length_quirk = (ep->chip->tx_length_quirk &&
629 usb_pipeout(ep->pipe));
631 if (pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
633 * When operating in DSD DOP mode, the size of a sample frame
634 * in hardware differs from the actual physical format width
635 * because we need to make room for the DOP markers.
637 frame_bits += channels << 3;
640 ep->datainterval = fmt->datainterval;
641 ep->stride = frame_bits >> 3;
643 switch (pcm_format) {
644 case SNDRV_PCM_FORMAT_U8:
645 ep->silence_value = 0x80;
647 case SNDRV_PCM_FORMAT_DSD_U8:
648 case SNDRV_PCM_FORMAT_DSD_U16_LE:
649 case SNDRV_PCM_FORMAT_DSD_U32_LE:
650 case SNDRV_PCM_FORMAT_DSD_U16_BE:
651 case SNDRV_PCM_FORMAT_DSD_U32_BE:
652 ep->silence_value = 0x69;
655 ep->silence_value = 0;
658 /* assume max. frequency is 50% higher than nominal */
659 ep->freqmax = ep->freqn + (ep->freqn >> 1);
660 /* Round up freqmax to nearest integer in order to calculate maximum
661 * packet size, which must represent a whole number of frames.
662 * This is accomplished by adding 0x0.ffff before converting the
663 * Q16.16 format into integer.
664 * In order to accurately calculate the maximum packet size when
665 * the data interval is more than 1 (i.e. ep->datainterval > 0),
666 * multiply by the data interval prior to rounding. For instance,
667 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
668 * frames with a data interval of 1, but 11 (10.25) frames with a
669 * data interval of 2.
670 * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
671 * maximum datainterval value of 3, at USB full speed, higher for
672 * USB high speed, noting that ep->freqmax is in units of
673 * frames per packet in Q16.16 format.)
675 maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
678 maxsize += sizeof(__le32); /* Space for length descriptor */
679 /* but wMaxPacketSize might reduce this */
680 if (ep->maxpacksize && ep->maxpacksize < maxsize) {
681 /* whatever fits into a max. size packet */
682 unsigned int data_maxsize = maxsize = ep->maxpacksize;
685 /* Need to remove the length descriptor to calc freq */
686 data_maxsize -= sizeof(__le32);
687 ep->freqmax = (data_maxsize / (frame_bits >> 3))
688 << (16 - ep->datainterval);
692 ep->curpacksize = ep->maxpacksize;
694 ep->curpacksize = maxsize;
696 if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
697 packs_per_ms = 8 >> ep->datainterval;
698 max_packs_per_urb = MAX_PACKS_HS;
701 max_packs_per_urb = MAX_PACKS;
703 if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep))
704 max_packs_per_urb = min(max_packs_per_urb,
705 1U << sync_ep->syncinterval);
706 max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);
709 * Capture endpoints need to use small URBs because there's no way
710 * to tell in advance where the next period will end, and we don't
711 * want the next URB to complete much after the period ends.
713 * Playback endpoints with implicit sync much use the same parameters
714 * as their corresponding capture endpoint.
716 if (usb_pipein(ep->pipe) ||
717 snd_usb_endpoint_implicit_feedback_sink(ep)) {
719 urb_packs = packs_per_ms;
721 * Wireless devices can poll at a max rate of once per 4ms.
722 * For dataintervals less than 5, increase the packet count to
723 * allow the host controller to use bursting to fill in the
726 if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_WIRELESS) {
727 int interval = ep->datainterval;
728 while (interval < 5) {
733 /* make capture URBs <= 1 ms and smaller than a period */
734 urb_packs = min(max_packs_per_urb, urb_packs);
735 while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
737 ep->nurbs = MAX_URBS;
740 * Playback endpoints without implicit sync are adjusted so that
741 * a period fits as evenly as possible in the smallest number of
742 * URBs. The total number of URBs is adjusted to the size of the
743 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
746 /* determine how small a packet can be */
747 minsize = (ep->freqn >> (16 - ep->datainterval)) *
749 /* with sync from device, assume it can be 12% lower */
751 minsize -= minsize >> 3;
752 minsize = max(minsize, 1u);
754 /* how many packets will contain an entire ALSA period? */
755 max_packs_per_period = DIV_ROUND_UP(period_bytes, minsize);
757 /* how many URBs will contain a period? */
758 urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
760 /* how many packets are needed in each URB? */
761 urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);
763 /* limit the number of frames in a single URB */
764 ep->max_urb_frames = DIV_ROUND_UP(frames_per_period,
767 /* try to use enough URBs to contain an entire ALSA buffer */
768 max_urbs = min((unsigned) MAX_URBS,
769 MAX_QUEUE * packs_per_ms / urb_packs);
770 ep->nurbs = min(max_urbs, urbs_per_period * periods_per_buffer);
773 /* allocate and initialize data urbs */
774 for (i = 0; i < ep->nurbs; i++) {
775 struct snd_urb_ctx *u = &ep->urb[i];
778 u->packets = urb_packs;
779 u->buffer_size = maxsize * u->packets;
781 if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
782 u->packets++; /* for transfer delimiter */
783 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
787 u->urb->transfer_buffer =
788 usb_alloc_coherent(ep->chip->dev, u->buffer_size,
789 GFP_KERNEL, &u->urb->transfer_dma);
790 if (!u->urb->transfer_buffer)
792 u->urb->pipe = ep->pipe;
793 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
794 u->urb->interval = 1 << ep->datainterval;
796 u->urb->complete = snd_complete_urb;
797 INIT_LIST_HEAD(&u->ready_list);
808 * configure a sync endpoint
810 static int sync_ep_set_params(struct snd_usb_endpoint *ep)
814 ep->syncbuf = usb_alloc_coherent(ep->chip->dev, SYNC_URBS * 4,
815 GFP_KERNEL, &ep->sync_dma);
819 for (i = 0; i < SYNC_URBS; i++) {
820 struct snd_urb_ctx *u = &ep->urb[i];
824 u->urb = usb_alloc_urb(1, GFP_KERNEL);
827 u->urb->transfer_buffer = ep->syncbuf + i * 4;
828 u->urb->transfer_dma = ep->sync_dma + i * 4;
829 u->urb->transfer_buffer_length = 4;
830 u->urb->pipe = ep->pipe;
831 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
832 u->urb->number_of_packets = 1;
833 u->urb->interval = 1 << ep->syncinterval;
835 u->urb->complete = snd_complete_urb;
838 ep->nurbs = SYNC_URBS;
848 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
850 * @ep: the snd_usb_endpoint to configure
851 * @pcm_format: the audio fomat.
852 * @channels: the number of audio channels.
853 * @period_bytes: the number of bytes in one alsa period.
854 * @period_frames: the number of frames in one alsa period.
855 * @buffer_periods: the number of periods in one alsa buffer.
856 * @rate: the frame rate.
857 * @fmt: the USB audio format information
858 * @sync_ep: the sync endpoint to use, if any
860 * Determine the number of URBs to be used on this endpoint.
861 * An endpoint must be configured before it can be started.
862 * An endpoint that is already running can not be reconfigured.
864 int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
865 snd_pcm_format_t pcm_format,
866 unsigned int channels,
867 unsigned int period_bytes,
868 unsigned int period_frames,
869 unsigned int buffer_periods,
871 struct audioformat *fmt,
872 struct snd_usb_endpoint *sync_ep)
876 if (ep->use_count != 0) {
877 usb_audio_warn(ep->chip,
878 "Unable to change format on ep #%x: already in use\n",
883 /* release old buffers, if any */
886 ep->datainterval = fmt->datainterval;
887 ep->maxpacksize = fmt->maxpacksize;
888 ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
890 if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL)
891 ep->freqn = get_usb_full_speed_rate(rate);
893 ep->freqn = get_usb_high_speed_rate(rate);
895 /* calculate the frequency in 16.16 format */
896 ep->freqm = ep->freqn;
897 ep->freqshift = INT_MIN;
902 case SND_USB_ENDPOINT_TYPE_DATA:
903 err = data_ep_set_params(ep, pcm_format, channels,
904 period_bytes, period_frames,
905 buffer_periods, fmt, sync_ep);
907 case SND_USB_ENDPOINT_TYPE_SYNC:
908 err = sync_ep_set_params(ep);
914 usb_audio_dbg(ep->chip,
915 "Setting params for ep #%x (type %d, %d urbs), ret=%d\n",
916 ep->ep_num, ep->type, ep->nurbs, err);
922 * snd_usb_endpoint_start: start an snd_usb_endpoint
924 * @ep: the endpoint to start
926 * A call to this function will increment the use count of the endpoint.
927 * In case it is not already running, the URBs for this endpoint will be
928 * submitted. Otherwise, this function does nothing.
930 * Must be balanced to calls of snd_usb_endpoint_stop().
932 * Returns an error if the URB submission failed, 0 in all other cases.
934 int snd_usb_endpoint_start(struct snd_usb_endpoint *ep)
939 if (atomic_read(&ep->chip->shutdown))
942 /* already running? */
943 if (++ep->use_count != 1)
946 /* just to be sure */
947 deactivate_urbs(ep, false);
953 snd_usb_endpoint_start_quirk(ep);
956 * If this endpoint has a data endpoint as implicit feedback source,
957 * don't start the urbs here. Instead, mark them all as available,
958 * wait for the record urbs to return and queue the playback urbs
962 set_bit(EP_FLAG_RUNNING, &ep->flags);
964 if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
965 for (i = 0; i < ep->nurbs; i++) {
966 struct snd_urb_ctx *ctx = ep->urb + i;
967 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
973 for (i = 0; i < ep->nurbs; i++) {
974 struct urb *urb = ep->urb[i].urb;
976 if (snd_BUG_ON(!urb))
979 if (usb_pipeout(ep->pipe)) {
980 prepare_outbound_urb(ep, urb->context);
982 prepare_inbound_urb(ep, urb->context);
985 err = usb_submit_urb(urb, GFP_ATOMIC);
987 usb_audio_err(ep->chip,
988 "cannot submit urb %d, error %d: %s\n",
989 i, err, usb_error_string(err));
992 set_bit(i, &ep->active_mask);
998 clear_bit(EP_FLAG_RUNNING, &ep->flags);
1000 deactivate_urbs(ep, false);
1005 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
1007 * @ep: the endpoint to stop (may be NULL)
1009 * A call to this function will decrement the use count of the endpoint.
1010 * In case the last user has requested the endpoint stop, the URBs will
1011 * actually be deactivated.
1013 * Must be balanced to calls of snd_usb_endpoint_start().
1015 * The caller needs to synchronize the pending stop operation via
1016 * snd_usb_endpoint_sync_pending_stop().
1018 void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep)
1023 if (snd_BUG_ON(ep->use_count == 0))
1026 if (--ep->use_count == 0) {
1027 deactivate_urbs(ep, false);
1028 set_bit(EP_FLAG_STOPPING, &ep->flags);
1033 * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint
1035 * @ep: the endpoint to deactivate
1037 * If the endpoint is not currently in use, this functions will
1038 * deactivate its associated URBs.
1040 * In case of any active users, this functions does nothing.
1042 void snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep)
1047 if (ep->use_count != 0)
1050 deactivate_urbs(ep, true);
1051 wait_clear_urbs(ep);
1055 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
1057 * @ep: the endpoint to release
1059 * This function does not care for the endpoint's use count but will tear
1060 * down all the streaming URBs immediately.
1062 void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
1064 release_urbs(ep, 1);
1068 * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint
1070 * @ep: the endpoint to free
1072 * This free all resources of the given ep.
1074 void snd_usb_endpoint_free(struct snd_usb_endpoint *ep)
1080 * snd_usb_handle_sync_urb: parse an USB sync packet
1082 * @ep: the endpoint to handle the packet
1083 * @sender: the sending endpoint
1084 * @urb: the received packet
1086 * This function is called from the context of an endpoint that received
1087 * the packet and is used to let another endpoint object handle the payload.
1089 void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
1090 struct snd_usb_endpoint *sender,
1091 const struct urb *urb)
1095 unsigned long flags;
1097 snd_BUG_ON(ep == sender);
1100 * In case the endpoint is operating in implicit feedback mode, prepare
1101 * a new outbound URB that has the same layout as the received packet
1102 * and add it to the list of pending urbs. queue_pending_output_urbs()
1103 * will take care of them later.
1105 if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1106 ep->use_count != 0) {
1108 /* implicit feedback case */
1110 struct snd_urb_ctx *in_ctx;
1111 struct snd_usb_packet_info *out_packet;
1113 in_ctx = urb->context;
1115 /* Count overall packet size */
1116 for (i = 0; i < in_ctx->packets; i++)
1117 if (urb->iso_frame_desc[i].status == 0)
1118 bytes += urb->iso_frame_desc[i].actual_length;
1121 * skip empty packets. At least M-Audio's Fast Track Ultra stops
1122 * streaming once it received a 0-byte OUT URB
1127 spin_lock_irqsave(&ep->lock, flags);
1128 out_packet = ep->next_packet + ep->next_packet_write_pos;
1131 * Iterate through the inbound packet and prepare the lengths
1132 * for the output packet. The OUT packet we are about to send
1133 * will have the same amount of payload bytes per stride as the
1134 * IN packet we just received. Since the actual size is scaled
1135 * by the stride, use the sender stride to calculate the length
1136 * in case the number of channels differ between the implicitly
1137 * fed-back endpoint and the synchronizing endpoint.
1140 out_packet->packets = in_ctx->packets;
1141 for (i = 0; i < in_ctx->packets; i++) {
1142 if (urb->iso_frame_desc[i].status == 0)
1143 out_packet->packet_size[i] =
1144 urb->iso_frame_desc[i].actual_length / sender->stride;
1146 out_packet->packet_size[i] = 0;
1149 ep->next_packet_write_pos++;
1150 ep->next_packet_write_pos %= MAX_URBS;
1151 spin_unlock_irqrestore(&ep->lock, flags);
1152 queue_pending_output_urbs(ep);
1158 * process after playback sync complete
1160 * Full speed devices report feedback values in 10.14 format as samples
1161 * per frame, high speed devices in 16.16 format as samples per
1164 * Because the Audio Class 1 spec was written before USB 2.0, many high
1165 * speed devices use a wrong interpretation, some others use an
1166 * entirely different format.
1168 * Therefore, we cannot predict what format any particular device uses
1169 * and must detect it automatically.
1172 if (urb->iso_frame_desc[0].status != 0 ||
1173 urb->iso_frame_desc[0].actual_length < 3)
1176 f = le32_to_cpup(urb->transfer_buffer);
1177 if (urb->iso_frame_desc[0].actual_length == 3)
1185 if (unlikely(sender->tenor_fb_quirk)) {
1187 * Devices based on Tenor 8802 chipsets (TEAC UD-H01
1188 * and others) sometimes change the feedback value
1191 if (f < ep->freqn - 0x8000)
1193 else if (f > ep->freqn + 0x8000)
1195 } else if (unlikely(ep->freqshift == INT_MIN)) {
1197 * The first time we see a feedback value, determine its format
1198 * by shifting it left or right until it matches the nominal
1199 * frequency value. This assumes that the feedback does not
1200 * differ from the nominal value more than +50% or -25%.
1203 while (f < ep->freqn - ep->freqn / 4) {
1207 while (f > ep->freqn + ep->freqn / 2) {
1211 ep->freqshift = shift;
1212 } else if (ep->freqshift >= 0)
1213 f <<= ep->freqshift;
1215 f >>= -ep->freqshift;
1217 if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {
1219 * If the frequency looks valid, set it.
1220 * This value is referred to in prepare_playback_urb().
1222 spin_lock_irqsave(&ep->lock, flags);
1224 spin_unlock_irqrestore(&ep->lock, flags);
1227 * Out of range; maybe the shift value is wrong.
1228 * Reset it so that we autodetect again the next time.
1230 ep->freqshift = INT_MIN;