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;
331 spin_lock_irqsave(&ep->lock, flags);
332 if (ep->next_packet_read_pos != ep->next_packet_write_pos) {
333 packet = ep->next_packet + ep->next_packet_read_pos;
334 ep->next_packet_read_pos++;
335 ep->next_packet_read_pos %= MAX_URBS;
337 /* take URB out of FIFO */
338 if (!list_empty(&ep->ready_playback_urbs))
339 ctx = list_first_entry(&ep->ready_playback_urbs,
340 struct snd_urb_ctx, ready_list);
342 spin_unlock_irqrestore(&ep->lock, flags);
347 list_del_init(&ctx->ready_list);
350 /* copy over the length information */
351 for (i = 0; i < packet->packets; i++)
352 ctx->packet_size[i] = packet->packet_size[i];
354 /* call the data handler to fill in playback data */
355 prepare_outbound_urb(ep, ctx);
357 err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
359 usb_audio_err(ep->chip,
360 "Unable to submit urb #%d: %d (urb %p)\n",
361 ctx->index, err, ctx->urb);
363 set_bit(ctx->index, &ep->active_mask);
368 * complete callback for urbs
370 static void snd_complete_urb(struct urb *urb)
372 struct snd_urb_ctx *ctx = urb->context;
373 struct snd_usb_endpoint *ep = ctx->ep;
374 struct snd_pcm_substream *substream;
378 if (unlikely(urb->status == -ENOENT || /* unlinked */
379 urb->status == -ENODEV || /* device removed */
380 urb->status == -ECONNRESET || /* unlinked */
381 urb->status == -ESHUTDOWN)) /* device disabled */
383 /* device disconnected */
384 if (unlikely(atomic_read(&ep->chip->shutdown)))
387 if (usb_pipeout(ep->pipe)) {
388 retire_outbound_urb(ep, ctx);
389 /* can be stopped during retire callback */
390 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
393 if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
394 spin_lock_irqsave(&ep->lock, flags);
395 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
396 spin_unlock_irqrestore(&ep->lock, flags);
397 queue_pending_output_urbs(ep);
402 prepare_outbound_urb(ep, ctx);
404 retire_inbound_urb(ep, ctx);
405 /* can be stopped during retire callback */
406 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
409 prepare_inbound_urb(ep, ctx);
412 err = usb_submit_urb(urb, GFP_ATOMIC);
416 usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
417 if (ep->data_subs && ep->data_subs->pcm_substream) {
418 substream = ep->data_subs->pcm_substream;
419 snd_pcm_stop_xrun(substream);
423 clear_bit(ctx->index, &ep->active_mask);
427 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
430 * @alts: The USB host interface
431 * @ep_num: The number of the endpoint to use
432 * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE
433 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
435 * If the requested endpoint has not been added to the given chip before,
436 * a new instance is created. Otherwise, a pointer to the previoulsy
437 * created instance is returned. In case of any error, NULL is returned.
439 * New endpoints will be added to chip->ep_list and must be freed by
440 * calling snd_usb_endpoint_free().
442 * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
443 * bNumEndpoints > 1 beforehand.
445 struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip,
446 struct usb_host_interface *alts,
447 int ep_num, int direction, int type)
449 struct snd_usb_endpoint *ep;
450 int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK;
455 mutex_lock(&chip->mutex);
457 list_for_each_entry(ep, &chip->ep_list, list) {
458 if (ep->ep_num == ep_num &&
459 ep->iface == alts->desc.bInterfaceNumber &&
460 ep->altsetting == alts->desc.bAlternateSetting) {
461 usb_audio_dbg(ep->chip,
462 "Re-using EP %x in iface %d,%d @%p\n",
463 ep_num, ep->iface, ep->altsetting, ep);
468 usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n",
469 is_playback ? "playback" : "capture",
470 type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync",
473 ep = kzalloc(sizeof(*ep), GFP_KERNEL);
478 spin_lock_init(&ep->lock);
481 ep->iface = alts->desc.bInterfaceNumber;
482 ep->altsetting = alts->desc.bAlternateSetting;
483 INIT_LIST_HEAD(&ep->ready_playback_urbs);
484 ep_num &= USB_ENDPOINT_NUMBER_MASK;
487 ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
489 ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);
491 if (type == SND_USB_ENDPOINT_TYPE_SYNC) {
492 if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
493 get_endpoint(alts, 1)->bRefresh >= 1 &&
494 get_endpoint(alts, 1)->bRefresh <= 9)
495 ep->syncinterval = get_endpoint(alts, 1)->bRefresh;
496 else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
497 ep->syncinterval = 1;
498 else if (get_endpoint(alts, 1)->bInterval >= 1 &&
499 get_endpoint(alts, 1)->bInterval <= 16)
500 ep->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
502 ep->syncinterval = 3;
504 ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize);
507 list_add_tail(&ep->list, &chip->ep_list);
510 mutex_unlock(&chip->mutex);
516 * wait until all urbs are processed.
518 static int wait_clear_urbs(struct snd_usb_endpoint *ep)
520 unsigned long end_time = jiffies + msecs_to_jiffies(1000);
524 alive = bitmap_weight(&ep->active_mask, ep->nurbs);
528 schedule_timeout_uninterruptible(1);
529 } while (time_before(jiffies, end_time));
532 usb_audio_err(ep->chip,
533 "timeout: still %d active urbs on EP #%x\n",
535 clear_bit(EP_FLAG_STOPPING, &ep->flags);
540 /* sync the pending stop operation;
541 * this function itself doesn't trigger the stop operation
543 void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
545 if (ep && test_bit(EP_FLAG_STOPPING, &ep->flags))
550 * unlink active urbs.
552 static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force)
556 if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */
559 clear_bit(EP_FLAG_RUNNING, &ep->flags);
561 INIT_LIST_HEAD(&ep->ready_playback_urbs);
562 ep->next_packet_read_pos = 0;
563 ep->next_packet_write_pos = 0;
565 for (i = 0; i < ep->nurbs; i++) {
566 if (test_bit(i, &ep->active_mask)) {
567 if (!test_and_set_bit(i, &ep->unlink_mask)) {
568 struct urb *u = ep->urb[i].urb;
578 * release an endpoint's urbs
580 static void release_urbs(struct snd_usb_endpoint *ep, int force)
584 /* route incoming urbs to nirvana */
585 ep->retire_data_urb = NULL;
586 ep->prepare_data_urb = NULL;
589 deactivate_urbs(ep, force);
592 for (i = 0; i < ep->nurbs; i++)
593 release_urb_ctx(&ep->urb[i]);
596 usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
597 ep->syncbuf, ep->sync_dma);
604 * configure a data endpoint
606 static int data_ep_set_params(struct snd_usb_endpoint *ep,
607 snd_pcm_format_t pcm_format,
608 unsigned int channels,
609 unsigned int period_bytes,
610 unsigned int frames_per_period,
611 unsigned int periods_per_buffer,
612 struct audioformat *fmt,
613 struct snd_usb_endpoint *sync_ep)
615 unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
616 unsigned int max_packs_per_period, urbs_per_period, urb_packs;
617 unsigned int max_urbs, i;
618 int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
619 int tx_length_quirk = (ep->chip->tx_length_quirk &&
620 usb_pipeout(ep->pipe));
622 if (pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
624 * When operating in DSD DOP mode, the size of a sample frame
625 * in hardware differs from the actual physical format width
626 * because we need to make room for the DOP markers.
628 frame_bits += channels << 3;
631 ep->datainterval = fmt->datainterval;
632 ep->stride = frame_bits >> 3;
633 ep->silence_value = pcm_format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0;
635 /* assume max. frequency is 25% higher than nominal */
636 ep->freqmax = ep->freqn + (ep->freqn >> 2);
637 /* Round up freqmax to nearest integer in order to calculate maximum
638 * packet size, which must represent a whole number of frames.
639 * This is accomplished by adding 0x0.ffff before converting the
640 * Q16.16 format into integer.
641 * In order to accurately calculate the maximum packet size when
642 * the data interval is more than 1 (i.e. ep->datainterval > 0),
643 * multiply by the data interval prior to rounding. For instance,
644 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
645 * frames with a data interval of 1, but 11 (10.25) frames with a
646 * data interval of 2.
647 * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
648 * maximum datainterval value of 3, at USB full speed, higher for
649 * USB high speed, noting that ep->freqmax is in units of
650 * frames per packet in Q16.16 format.)
652 maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
655 maxsize += sizeof(__le32); /* Space for length descriptor */
656 /* but wMaxPacketSize might reduce this */
657 if (ep->maxpacksize && ep->maxpacksize < maxsize) {
658 /* whatever fits into a max. size packet */
659 unsigned int data_maxsize = maxsize = ep->maxpacksize;
662 /* Need to remove the length descriptor to calc freq */
663 data_maxsize -= sizeof(__le32);
664 ep->freqmax = (data_maxsize / (frame_bits >> 3))
665 << (16 - ep->datainterval);
669 ep->curpacksize = ep->maxpacksize;
671 ep->curpacksize = maxsize;
673 if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
674 packs_per_ms = 8 >> ep->datainterval;
675 max_packs_per_urb = MAX_PACKS_HS;
678 max_packs_per_urb = MAX_PACKS;
680 if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep))
681 max_packs_per_urb = min(max_packs_per_urb,
682 1U << sync_ep->syncinterval);
683 max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);
686 * Capture endpoints need to use small URBs because there's no way
687 * to tell in advance where the next period will end, and we don't
688 * want the next URB to complete much after the period ends.
690 * Playback endpoints with implicit sync much use the same parameters
691 * as their corresponding capture endpoint.
693 if (usb_pipein(ep->pipe) ||
694 snd_usb_endpoint_implicit_feedback_sink(ep)) {
696 urb_packs = packs_per_ms;
698 * Wireless devices can poll at a max rate of once per 4ms.
699 * For dataintervals less than 5, increase the packet count to
700 * allow the host controller to use bursting to fill in the
703 if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_WIRELESS) {
704 int interval = ep->datainterval;
705 while (interval < 5) {
710 /* make capture URBs <= 1 ms and smaller than a period */
711 urb_packs = min(max_packs_per_urb, urb_packs);
712 while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
714 ep->nurbs = MAX_URBS;
717 * Playback endpoints without implicit sync are adjusted so that
718 * a period fits as evenly as possible in the smallest number of
719 * URBs. The total number of URBs is adjusted to the size of the
720 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
723 /* determine how small a packet can be */
724 minsize = (ep->freqn >> (16 - ep->datainterval)) *
726 /* with sync from device, assume it can be 12% lower */
728 minsize -= minsize >> 3;
729 minsize = max(minsize, 1u);
731 /* how many packets will contain an entire ALSA period? */
732 max_packs_per_period = DIV_ROUND_UP(period_bytes, minsize);
734 /* how many URBs will contain a period? */
735 urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
737 /* how many packets are needed in each URB? */
738 urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);
740 /* limit the number of frames in a single URB */
741 ep->max_urb_frames = DIV_ROUND_UP(frames_per_period,
744 /* try to use enough URBs to contain an entire ALSA buffer */
745 max_urbs = min((unsigned) MAX_URBS,
746 MAX_QUEUE * packs_per_ms / urb_packs);
747 ep->nurbs = min(max_urbs, urbs_per_period * periods_per_buffer);
750 /* allocate and initialize data urbs */
751 for (i = 0; i < ep->nurbs; i++) {
752 struct snd_urb_ctx *u = &ep->urb[i];
755 u->packets = urb_packs;
756 u->buffer_size = maxsize * u->packets;
758 if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
759 u->packets++; /* for transfer delimiter */
760 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
764 u->urb->transfer_buffer =
765 usb_alloc_coherent(ep->chip->dev, u->buffer_size,
766 GFP_KERNEL, &u->urb->transfer_dma);
767 if (!u->urb->transfer_buffer)
769 u->urb->pipe = ep->pipe;
770 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
771 u->urb->interval = 1 << ep->datainterval;
773 u->urb->complete = snd_complete_urb;
774 INIT_LIST_HEAD(&u->ready_list);
785 * configure a sync endpoint
787 static int sync_ep_set_params(struct snd_usb_endpoint *ep)
791 ep->syncbuf = usb_alloc_coherent(ep->chip->dev, SYNC_URBS * 4,
792 GFP_KERNEL, &ep->sync_dma);
796 for (i = 0; i < SYNC_URBS; i++) {
797 struct snd_urb_ctx *u = &ep->urb[i];
801 u->urb = usb_alloc_urb(1, GFP_KERNEL);
804 u->urb->transfer_buffer = ep->syncbuf + i * 4;
805 u->urb->transfer_dma = ep->sync_dma + i * 4;
806 u->urb->transfer_buffer_length = 4;
807 u->urb->pipe = ep->pipe;
808 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
809 u->urb->number_of_packets = 1;
810 u->urb->interval = 1 << ep->syncinterval;
812 u->urb->complete = snd_complete_urb;
815 ep->nurbs = SYNC_URBS;
825 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
827 * @ep: the snd_usb_endpoint to configure
828 * @pcm_format: the audio fomat.
829 * @channels: the number of audio channels.
830 * @period_bytes: the number of bytes in one alsa period.
831 * @period_frames: the number of frames in one alsa period.
832 * @buffer_periods: the number of periods in one alsa buffer.
833 * @rate: the frame rate.
834 * @fmt: the USB audio format information
835 * @sync_ep: the sync endpoint to use, if any
837 * Determine the number of URBs to be used on this endpoint.
838 * An endpoint must be configured before it can be started.
839 * An endpoint that is already running can not be reconfigured.
841 int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
842 snd_pcm_format_t pcm_format,
843 unsigned int channels,
844 unsigned int period_bytes,
845 unsigned int period_frames,
846 unsigned int buffer_periods,
848 struct audioformat *fmt,
849 struct snd_usb_endpoint *sync_ep)
853 if (ep->use_count != 0) {
854 usb_audio_warn(ep->chip,
855 "Unable to change format on ep #%x: already in use\n",
860 /* release old buffers, if any */
863 ep->datainterval = fmt->datainterval;
864 ep->maxpacksize = fmt->maxpacksize;
865 ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
867 if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL)
868 ep->freqn = get_usb_full_speed_rate(rate);
870 ep->freqn = get_usb_high_speed_rate(rate);
872 /* calculate the frequency in 16.16 format */
873 ep->freqm = ep->freqn;
874 ep->freqshift = INT_MIN;
879 case SND_USB_ENDPOINT_TYPE_DATA:
880 err = data_ep_set_params(ep, pcm_format, channels,
881 period_bytes, period_frames,
882 buffer_periods, fmt, sync_ep);
884 case SND_USB_ENDPOINT_TYPE_SYNC:
885 err = sync_ep_set_params(ep);
891 usb_audio_dbg(ep->chip,
892 "Setting params for ep #%x (type %d, %d urbs), ret=%d\n",
893 ep->ep_num, ep->type, ep->nurbs, err);
899 * snd_usb_endpoint_start: start an snd_usb_endpoint
901 * @ep: the endpoint to start
902 * @can_sleep: flag indicating whether the operation is executed in
905 * A call to this function will increment the use count of the endpoint.
906 * In case it is not already running, the URBs for this endpoint will be
907 * submitted. Otherwise, this function does nothing.
909 * Must be balanced to calls of snd_usb_endpoint_stop().
911 * Returns an error if the URB submission failed, 0 in all other cases.
913 int snd_usb_endpoint_start(struct snd_usb_endpoint *ep, bool can_sleep)
918 if (atomic_read(&ep->chip->shutdown))
921 /* already running? */
922 if (++ep->use_count != 1)
925 /* just to be sure */
926 deactivate_urbs(ep, false);
934 snd_usb_endpoint_start_quirk(ep);
937 * If this endpoint has a data endpoint as implicit feedback source,
938 * don't start the urbs here. Instead, mark them all as available,
939 * wait for the record urbs to return and queue the playback urbs
943 set_bit(EP_FLAG_RUNNING, &ep->flags);
945 if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
946 for (i = 0; i < ep->nurbs; i++) {
947 struct snd_urb_ctx *ctx = ep->urb + i;
948 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
954 for (i = 0; i < ep->nurbs; i++) {
955 struct urb *urb = ep->urb[i].urb;
957 if (snd_BUG_ON(!urb))
960 if (usb_pipeout(ep->pipe)) {
961 prepare_outbound_urb(ep, urb->context);
963 prepare_inbound_urb(ep, urb->context);
966 err = usb_submit_urb(urb, GFP_ATOMIC);
968 usb_audio_err(ep->chip,
969 "cannot submit urb %d, error %d: %s\n",
970 i, err, usb_error_string(err));
973 set_bit(i, &ep->active_mask);
979 clear_bit(EP_FLAG_RUNNING, &ep->flags);
981 deactivate_urbs(ep, false);
986 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
988 * @ep: the endpoint to stop (may be NULL)
990 * A call to this function will decrement the use count of the endpoint.
991 * In case the last user has requested the endpoint stop, the URBs will
992 * actually be deactivated.
994 * Must be balanced to calls of snd_usb_endpoint_start().
996 * The caller needs to synchronize the pending stop operation via
997 * snd_usb_endpoint_sync_pending_stop().
999 void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep)
1004 if (snd_BUG_ON(ep->use_count == 0))
1007 if (--ep->use_count == 0) {
1008 deactivate_urbs(ep, false);
1009 ep->data_subs = NULL;
1010 ep->sync_slave = NULL;
1011 ep->retire_data_urb = NULL;
1012 ep->prepare_data_urb = NULL;
1013 set_bit(EP_FLAG_STOPPING, &ep->flags);
1018 * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint
1020 * @ep: the endpoint to deactivate
1022 * If the endpoint is not currently in use, this functions will
1023 * deactivate its associated URBs.
1025 * In case of any active users, this functions does nothing.
1027 void snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep)
1032 if (ep->use_count != 0)
1035 deactivate_urbs(ep, true);
1036 wait_clear_urbs(ep);
1040 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
1042 * @ep: the endpoint to release
1044 * This function does not care for the endpoint's use count but will tear
1045 * down all the streaming URBs immediately.
1047 void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
1049 release_urbs(ep, 1);
1053 * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint
1055 * @ep: the endpoint to free
1057 * This free all resources of the given ep.
1059 void snd_usb_endpoint_free(struct snd_usb_endpoint *ep)
1065 * snd_usb_handle_sync_urb: parse an USB sync packet
1067 * @ep: the endpoint to handle the packet
1068 * @sender: the sending endpoint
1069 * @urb: the received packet
1071 * This function is called from the context of an endpoint that received
1072 * the packet and is used to let another endpoint object handle the payload.
1074 void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
1075 struct snd_usb_endpoint *sender,
1076 const struct urb *urb)
1080 unsigned long flags;
1082 snd_BUG_ON(ep == sender);
1085 * In case the endpoint is operating in implicit feedback mode, prepare
1086 * a new outbound URB that has the same layout as the received packet
1087 * and add it to the list of pending urbs. queue_pending_output_urbs()
1088 * will take care of them later.
1090 if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1091 ep->use_count != 0) {
1093 /* implicit feedback case */
1095 struct snd_urb_ctx *in_ctx;
1096 struct snd_usb_packet_info *out_packet;
1098 in_ctx = urb->context;
1100 /* Count overall packet size */
1101 for (i = 0; i < in_ctx->packets; i++)
1102 if (urb->iso_frame_desc[i].status == 0)
1103 bytes += urb->iso_frame_desc[i].actual_length;
1106 * skip empty packets. At least M-Audio's Fast Track Ultra stops
1107 * streaming once it received a 0-byte OUT URB
1112 spin_lock_irqsave(&ep->lock, flags);
1113 out_packet = ep->next_packet + ep->next_packet_write_pos;
1116 * Iterate through the inbound packet and prepare the lengths
1117 * for the output packet. The OUT packet we are about to send
1118 * will have the same amount of payload bytes per stride as the
1119 * IN packet we just received. Since the actual size is scaled
1120 * by the stride, use the sender stride to calculate the length
1121 * in case the number of channels differ between the implicitly
1122 * fed-back endpoint and the synchronizing endpoint.
1125 out_packet->packets = in_ctx->packets;
1126 for (i = 0; i < in_ctx->packets; i++) {
1127 if (urb->iso_frame_desc[i].status == 0)
1128 out_packet->packet_size[i] =
1129 urb->iso_frame_desc[i].actual_length / sender->stride;
1131 out_packet->packet_size[i] = 0;
1134 ep->next_packet_write_pos++;
1135 ep->next_packet_write_pos %= MAX_URBS;
1136 spin_unlock_irqrestore(&ep->lock, flags);
1137 queue_pending_output_urbs(ep);
1143 * process after playback sync complete
1145 * Full speed devices report feedback values in 10.14 format as samples
1146 * per frame, high speed devices in 16.16 format as samples per
1149 * Because the Audio Class 1 spec was written before USB 2.0, many high
1150 * speed devices use a wrong interpretation, some others use an
1151 * entirely different format.
1153 * Therefore, we cannot predict what format any particular device uses
1154 * and must detect it automatically.
1157 if (urb->iso_frame_desc[0].status != 0 ||
1158 urb->iso_frame_desc[0].actual_length < 3)
1161 f = le32_to_cpup(urb->transfer_buffer);
1162 if (urb->iso_frame_desc[0].actual_length == 3)
1170 if (unlikely(sender->tenor_fb_quirk)) {
1172 * Devices based on Tenor 8802 chipsets (TEAC UD-H01
1173 * and others) sometimes change the feedback value
1176 if (f < ep->freqn - 0x8000)
1178 else if (f > ep->freqn + 0x8000)
1180 } else if (unlikely(ep->freqshift == INT_MIN)) {
1182 * The first time we see a feedback value, determine its format
1183 * by shifting it left or right until it matches the nominal
1184 * frequency value. This assumes that the feedback does not
1185 * differ from the nominal value more than +50% or -25%.
1188 while (f < ep->freqn - ep->freqn / 4) {
1192 while (f > ep->freqn + ep->freqn / 2) {
1196 ep->freqshift = shift;
1197 } else if (ep->freqshift >= 0)
1198 f <<= ep->freqshift;
1200 f >>= -ep->freqshift;
1202 if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {
1204 * If the frequency looks valid, set it.
1205 * This value is referred to in prepare_playback_urb().
1207 spin_lock_irqsave(&ep->lock, flags);
1209 spin_unlock_irqrestore(&ep->lock, flags);
1212 * Out of range; maybe the shift value is wrong.
1213 * Reset it so that we autodetect again the next time.
1215 ep->freqshift = INT_MIN;