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;
193 for (i = 0; i < ctx->packets; ++i) {
196 if (ctx->packet_size[i])
197 counts = ctx->packet_size[i];
199 counts = snd_usb_endpoint_next_packet_size(ep);
201 urb->iso_frame_desc[i].offset = offs * ep->stride;
202 urb->iso_frame_desc[i].length = counts * ep->stride;
206 urb->number_of_packets = ctx->packets;
207 urb->transfer_buffer_length = offs * ep->stride;
208 memset(urb->transfer_buffer, ep->silence_value,
213 * Prepare a PLAYBACK urb for submission to the bus.
215 static void prepare_outbound_urb(struct snd_usb_endpoint *ep,
216 struct snd_urb_ctx *ctx)
218 struct urb *urb = ctx->urb;
219 unsigned char *cp = urb->transfer_buffer;
221 urb->dev = ep->chip->dev; /* we need to set this at each time */
224 case SND_USB_ENDPOINT_TYPE_DATA:
225 if (ep->prepare_data_urb) {
226 ep->prepare_data_urb(ep->data_subs, urb);
228 /* no data provider, so send silence */
229 prepare_silent_urb(ep, ctx);
233 case SND_USB_ENDPOINT_TYPE_SYNC:
234 if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) {
236 * fill the length and offset of each urb descriptor.
237 * the fixed 12.13 frequency is passed as 16.16 through the pipe.
239 urb->iso_frame_desc[0].length = 4;
240 urb->iso_frame_desc[0].offset = 0;
242 cp[1] = ep->freqn >> 8;
243 cp[2] = ep->freqn >> 16;
244 cp[3] = ep->freqn >> 24;
247 * fill the length and offset of each urb descriptor.
248 * the fixed 10.14 frequency is passed through the pipe.
250 urb->iso_frame_desc[0].length = 3;
251 urb->iso_frame_desc[0].offset = 0;
252 cp[0] = ep->freqn >> 2;
253 cp[1] = ep->freqn >> 10;
254 cp[2] = ep->freqn >> 18;
262 * Prepare a CAPTURE or SYNC urb for submission to the bus.
264 static inline void prepare_inbound_urb(struct snd_usb_endpoint *ep,
265 struct snd_urb_ctx *urb_ctx)
268 struct urb *urb = urb_ctx->urb;
270 urb->dev = ep->chip->dev; /* we need to set this at each time */
273 case SND_USB_ENDPOINT_TYPE_DATA:
275 for (i = 0; i < urb_ctx->packets; i++) {
276 urb->iso_frame_desc[i].offset = offs;
277 urb->iso_frame_desc[i].length = ep->curpacksize;
278 offs += ep->curpacksize;
281 urb->transfer_buffer_length = offs;
282 urb->number_of_packets = urb_ctx->packets;
285 case SND_USB_ENDPOINT_TYPE_SYNC:
286 urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize);
287 urb->iso_frame_desc[0].offset = 0;
293 * Send output urbs that have been prepared previously. URBs are dequeued
294 * from ep->ready_playback_urbs and in case there there aren't any available
295 * or there are no packets that have been prepared, this function does
298 * The reason why the functionality of sending and preparing URBs is separated
299 * is that host controllers don't guarantee the order in which they return
300 * inbound and outbound packets to their submitters.
302 * This function is only used for implicit feedback endpoints. For endpoints
303 * driven by dedicated sync endpoints, URBs are immediately re-submitted
304 * from their completion handler.
306 static void queue_pending_output_urbs(struct snd_usb_endpoint *ep)
308 while (test_bit(EP_FLAG_RUNNING, &ep->flags)) {
311 struct snd_usb_packet_info *uninitialized_var(packet);
312 struct snd_urb_ctx *ctx = NULL;
316 spin_lock_irqsave(&ep->lock, flags);
317 if (ep->next_packet_read_pos != ep->next_packet_write_pos) {
318 packet = ep->next_packet + ep->next_packet_read_pos;
319 ep->next_packet_read_pos++;
320 ep->next_packet_read_pos %= MAX_URBS;
322 /* take URB out of FIFO */
323 if (!list_empty(&ep->ready_playback_urbs))
324 ctx = list_first_entry(&ep->ready_playback_urbs,
325 struct snd_urb_ctx, ready_list);
327 spin_unlock_irqrestore(&ep->lock, flags);
332 list_del_init(&ctx->ready_list);
335 /* copy over the length information */
336 for (i = 0; i < packet->packets; i++)
337 ctx->packet_size[i] = packet->packet_size[i];
339 /* call the data handler to fill in playback data */
340 prepare_outbound_urb(ep, ctx);
342 err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
344 usb_audio_err(ep->chip,
345 "Unable to submit urb #%d: %d (urb %p)\n",
346 ctx->index, err, ctx->urb);
348 set_bit(ctx->index, &ep->active_mask);
353 * complete callback for urbs
355 static void snd_complete_urb(struct urb *urb)
357 struct snd_urb_ctx *ctx = urb->context;
358 struct snd_usb_endpoint *ep = ctx->ep;
359 struct snd_pcm_substream *substream;
363 if (unlikely(urb->status == -ENOENT || /* unlinked */
364 urb->status == -ENODEV || /* device removed */
365 urb->status == -ECONNRESET || /* unlinked */
366 urb->status == -ESHUTDOWN)) /* device disabled */
368 /* device disconnected */
369 if (unlikely(atomic_read(&ep->chip->shutdown)))
372 if (usb_pipeout(ep->pipe)) {
373 retire_outbound_urb(ep, ctx);
374 /* can be stopped during retire callback */
375 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
378 if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
379 spin_lock_irqsave(&ep->lock, flags);
380 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
381 spin_unlock_irqrestore(&ep->lock, flags);
382 queue_pending_output_urbs(ep);
387 prepare_outbound_urb(ep, ctx);
389 retire_inbound_urb(ep, ctx);
390 /* can be stopped during retire callback */
391 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
394 prepare_inbound_urb(ep, ctx);
397 err = usb_submit_urb(urb, GFP_ATOMIC);
401 usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
402 if (ep->data_subs && ep->data_subs->pcm_substream) {
403 substream = ep->data_subs->pcm_substream;
404 snd_pcm_stop_xrun(substream);
408 clear_bit(ctx->index, &ep->active_mask);
412 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
415 * @alts: The USB host interface
416 * @ep_num: The number of the endpoint to use
417 * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE
418 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
420 * If the requested endpoint has not been added to the given chip before,
421 * a new instance is created. Otherwise, a pointer to the previoulsy
422 * created instance is returned. In case of any error, NULL is returned.
424 * New endpoints will be added to chip->ep_list and must be freed by
425 * calling snd_usb_endpoint_free().
427 struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip,
428 struct usb_host_interface *alts,
429 int ep_num, int direction, int type)
431 struct snd_usb_endpoint *ep;
432 int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK;
437 mutex_lock(&chip->mutex);
439 list_for_each_entry(ep, &chip->ep_list, list) {
440 if (ep->ep_num == ep_num &&
441 ep->iface == alts->desc.bInterfaceNumber &&
442 ep->altsetting == alts->desc.bAlternateSetting) {
443 usb_audio_dbg(ep->chip,
444 "Re-using EP %x in iface %d,%d @%p\n",
445 ep_num, ep->iface, ep->altsetting, ep);
450 usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n",
451 is_playback ? "playback" : "capture",
452 type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync",
455 ep = kzalloc(sizeof(*ep), GFP_KERNEL);
460 spin_lock_init(&ep->lock);
463 ep->iface = alts->desc.bInterfaceNumber;
464 ep->altsetting = alts->desc.bAlternateSetting;
465 INIT_LIST_HEAD(&ep->ready_playback_urbs);
466 ep_num &= USB_ENDPOINT_NUMBER_MASK;
469 ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
471 ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);
473 if (type == SND_USB_ENDPOINT_TYPE_SYNC) {
474 if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
475 get_endpoint(alts, 1)->bRefresh >= 1 &&
476 get_endpoint(alts, 1)->bRefresh <= 9)
477 ep->syncinterval = get_endpoint(alts, 1)->bRefresh;
478 else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
479 ep->syncinterval = 1;
480 else if (get_endpoint(alts, 1)->bInterval >= 1 &&
481 get_endpoint(alts, 1)->bInterval <= 16)
482 ep->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
484 ep->syncinterval = 3;
486 ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize);
488 if (chip->usb_id == USB_ID(0x0644, 0x8038) /* TEAC UD-H01 */ &&
489 ep->syncmaxsize == 4)
490 ep->udh01_fb_quirk = 1;
493 list_add_tail(&ep->list, &chip->ep_list);
496 mutex_unlock(&chip->mutex);
502 * wait until all urbs are processed.
504 static int wait_clear_urbs(struct snd_usb_endpoint *ep)
506 unsigned long end_time = jiffies + msecs_to_jiffies(1000);
510 alive = bitmap_weight(&ep->active_mask, ep->nurbs);
514 schedule_timeout_uninterruptible(1);
515 } while (time_before(jiffies, end_time));
518 usb_audio_err(ep->chip,
519 "timeout: still %d active urbs on EP #%x\n",
521 clear_bit(EP_FLAG_STOPPING, &ep->flags);
526 /* sync the pending stop operation;
527 * this function itself doesn't trigger the stop operation
529 void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
531 if (ep && test_bit(EP_FLAG_STOPPING, &ep->flags))
536 * unlink active urbs.
538 static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force)
542 if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */
545 clear_bit(EP_FLAG_RUNNING, &ep->flags);
547 INIT_LIST_HEAD(&ep->ready_playback_urbs);
548 ep->next_packet_read_pos = 0;
549 ep->next_packet_write_pos = 0;
551 for (i = 0; i < ep->nurbs; i++) {
552 if (test_bit(i, &ep->active_mask)) {
553 if (!test_and_set_bit(i, &ep->unlink_mask)) {
554 struct urb *u = ep->urb[i].urb;
564 * release an endpoint's urbs
566 static void release_urbs(struct snd_usb_endpoint *ep, int force)
570 /* route incoming urbs to nirvana */
571 ep->retire_data_urb = NULL;
572 ep->prepare_data_urb = NULL;
575 deactivate_urbs(ep, force);
578 for (i = 0; i < ep->nurbs; i++)
579 release_urb_ctx(&ep->urb[i]);
582 usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
583 ep->syncbuf, ep->sync_dma);
590 * configure a data endpoint
592 static int data_ep_set_params(struct snd_usb_endpoint *ep,
593 snd_pcm_format_t pcm_format,
594 unsigned int channels,
595 unsigned int period_bytes,
596 unsigned int frames_per_period,
597 unsigned int periods_per_buffer,
598 struct audioformat *fmt,
599 struct snd_usb_endpoint *sync_ep)
601 unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
602 unsigned int max_packs_per_period, urbs_per_period, urb_packs;
603 unsigned int max_urbs, i;
604 int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
606 if (pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
608 * When operating in DSD DOP mode, the size of a sample frame
609 * in hardware differs from the actual physical format width
610 * because we need to make room for the DOP markers.
612 frame_bits += channels << 3;
615 ep->datainterval = fmt->datainterval;
616 ep->stride = frame_bits >> 3;
617 ep->silence_value = pcm_format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0;
619 /* assume max. frequency is 25% higher than nominal */
620 ep->freqmax = ep->freqn + (ep->freqn >> 2);
621 /* Round up freqmax to nearest integer in order to calculate maximum
622 * packet size, which must represent a whole number of frames.
623 * This is accomplished by adding 0x0.ffff before converting the
624 * Q16.16 format into integer.
625 * In order to accurately calculate the maximum packet size when
626 * the data interval is more than 1 (i.e. ep->datainterval > 0),
627 * multiply by the data interval prior to rounding. For instance,
628 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
629 * frames with a data interval of 1, but 11 (10.25) frames with a
630 * data interval of 2.
631 * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
632 * maximum datainterval value of 3, at USB full speed, higher for
633 * USB high speed, noting that ep->freqmax is in units of
634 * frames per packet in Q16.16 format.)
636 maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
638 /* but wMaxPacketSize might reduce this */
639 if (ep->maxpacksize && ep->maxpacksize < maxsize) {
640 /* whatever fits into a max. size packet */
641 maxsize = ep->maxpacksize;
642 ep->freqmax = (maxsize / (frame_bits >> 3))
643 << (16 - ep->datainterval);
647 ep->curpacksize = ep->maxpacksize;
649 ep->curpacksize = maxsize;
651 if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
652 packs_per_ms = 8 >> ep->datainterval;
653 max_packs_per_urb = MAX_PACKS_HS;
656 max_packs_per_urb = MAX_PACKS;
658 if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep))
659 max_packs_per_urb = min(max_packs_per_urb,
660 1U << sync_ep->syncinterval);
661 max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);
664 * Capture endpoints need to use small URBs because there's no way
665 * to tell in advance where the next period will end, and we don't
666 * want the next URB to complete much after the period ends.
668 * Playback endpoints with implicit sync much use the same parameters
669 * as their corresponding capture endpoint.
671 if (usb_pipein(ep->pipe) ||
672 snd_usb_endpoint_implicit_feedback_sink(ep)) {
674 urb_packs = packs_per_ms;
676 * Wireless devices can poll at a max rate of once per 4ms.
677 * For dataintervals less than 5, increase the packet count to
678 * allow the host controller to use bursting to fill in the
681 if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_WIRELESS) {
682 int interval = ep->datainterval;
683 while (interval < 5) {
688 /* make capture URBs <= 1 ms and smaller than a period */
689 urb_packs = min(max_packs_per_urb, urb_packs);
690 while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
692 ep->nurbs = MAX_URBS;
695 * Playback endpoints without implicit sync are adjusted so that
696 * a period fits as evenly as possible in the smallest number of
697 * URBs. The total number of URBs is adjusted to the size of the
698 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
701 /* determine how small a packet can be */
702 minsize = (ep->freqn >> (16 - ep->datainterval)) *
704 /* with sync from device, assume it can be 12% lower */
706 minsize -= minsize >> 3;
707 minsize = max(minsize, 1u);
709 /* how many packets will contain an entire ALSA period? */
710 max_packs_per_period = DIV_ROUND_UP(period_bytes, minsize);
712 /* how many URBs will contain a period? */
713 urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
715 /* how many packets are needed in each URB? */
716 urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);
718 /* limit the number of frames in a single URB */
719 ep->max_urb_frames = DIV_ROUND_UP(frames_per_period,
722 /* try to use enough URBs to contain an entire ALSA buffer */
723 max_urbs = min((unsigned) MAX_URBS,
724 MAX_QUEUE * packs_per_ms / urb_packs);
725 ep->nurbs = min(max_urbs, urbs_per_period * periods_per_buffer);
728 /* allocate and initialize data urbs */
729 for (i = 0; i < ep->nurbs; i++) {
730 struct snd_urb_ctx *u = &ep->urb[i];
733 u->packets = urb_packs;
734 u->buffer_size = maxsize * u->packets;
736 if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
737 u->packets++; /* for transfer delimiter */
738 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
742 u->urb->transfer_buffer =
743 usb_alloc_coherent(ep->chip->dev, u->buffer_size,
744 GFP_KERNEL, &u->urb->transfer_dma);
745 if (!u->urb->transfer_buffer)
747 u->urb->pipe = ep->pipe;
748 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
749 u->urb->interval = 1 << ep->datainterval;
751 u->urb->complete = snd_complete_urb;
752 INIT_LIST_HEAD(&u->ready_list);
763 * configure a sync endpoint
765 static int sync_ep_set_params(struct snd_usb_endpoint *ep)
769 ep->syncbuf = usb_alloc_coherent(ep->chip->dev, SYNC_URBS * 4,
770 GFP_KERNEL, &ep->sync_dma);
774 for (i = 0; i < SYNC_URBS; i++) {
775 struct snd_urb_ctx *u = &ep->urb[i];
779 u->urb = usb_alloc_urb(1, GFP_KERNEL);
782 u->urb->transfer_buffer = ep->syncbuf + i * 4;
783 u->urb->transfer_dma = ep->sync_dma + i * 4;
784 u->urb->transfer_buffer_length = 4;
785 u->urb->pipe = ep->pipe;
786 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
787 u->urb->number_of_packets = 1;
788 u->urb->interval = 1 << ep->syncinterval;
790 u->urb->complete = snd_complete_urb;
793 ep->nurbs = SYNC_URBS;
803 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
805 * @ep: the snd_usb_endpoint to configure
806 * @pcm_format: the audio fomat.
807 * @channels: the number of audio channels.
808 * @period_bytes: the number of bytes in one alsa period.
809 * @period_frames: the number of frames in one alsa period.
810 * @buffer_periods: the number of periods in one alsa buffer.
811 * @rate: the frame rate.
812 * @fmt: the USB audio format information
813 * @sync_ep: the sync endpoint to use, if any
815 * Determine the number of URBs to be used on this endpoint.
816 * An endpoint must be configured before it can be started.
817 * An endpoint that is already running can not be reconfigured.
819 int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
820 snd_pcm_format_t pcm_format,
821 unsigned int channels,
822 unsigned int period_bytes,
823 unsigned int period_frames,
824 unsigned int buffer_periods,
826 struct audioformat *fmt,
827 struct snd_usb_endpoint *sync_ep)
831 if (ep->use_count != 0) {
832 usb_audio_warn(ep->chip,
833 "Unable to change format on ep #%x: already in use\n",
838 /* release old buffers, if any */
841 ep->datainterval = fmt->datainterval;
842 ep->maxpacksize = fmt->maxpacksize;
843 ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
845 if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL)
846 ep->freqn = get_usb_full_speed_rate(rate);
848 ep->freqn = get_usb_high_speed_rate(rate);
850 /* calculate the frequency in 16.16 format */
851 ep->freqm = ep->freqn;
852 ep->freqshift = INT_MIN;
857 case SND_USB_ENDPOINT_TYPE_DATA:
858 err = data_ep_set_params(ep, pcm_format, channels,
859 period_bytes, period_frames,
860 buffer_periods, fmt, sync_ep);
862 case SND_USB_ENDPOINT_TYPE_SYNC:
863 err = sync_ep_set_params(ep);
869 usb_audio_dbg(ep->chip,
870 "Setting params for ep #%x (type %d, %d urbs), ret=%d\n",
871 ep->ep_num, ep->type, ep->nurbs, err);
877 * snd_usb_endpoint_start: start an snd_usb_endpoint
879 * @ep: the endpoint to start
880 * @can_sleep: flag indicating whether the operation is executed in
883 * A call to this function will increment the use count of the endpoint.
884 * In case it is not already running, the URBs for this endpoint will be
885 * submitted. Otherwise, this function does nothing.
887 * Must be balanced to calls of snd_usb_endpoint_stop().
889 * Returns an error if the URB submission failed, 0 in all other cases.
891 int snd_usb_endpoint_start(struct snd_usb_endpoint *ep, bool can_sleep)
896 if (atomic_read(&ep->chip->shutdown))
899 /* already running? */
900 if (++ep->use_count != 1)
903 /* just to be sure */
904 deactivate_urbs(ep, false);
912 snd_usb_endpoint_start_quirk(ep);
915 * If this endpoint has a data endpoint as implicit feedback source,
916 * don't start the urbs here. Instead, mark them all as available,
917 * wait for the record urbs to return and queue the playback urbs
921 set_bit(EP_FLAG_RUNNING, &ep->flags);
923 if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
924 for (i = 0; i < ep->nurbs; i++) {
925 struct snd_urb_ctx *ctx = ep->urb + i;
926 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
932 for (i = 0; i < ep->nurbs; i++) {
933 struct urb *urb = ep->urb[i].urb;
935 if (snd_BUG_ON(!urb))
938 if (usb_pipeout(ep->pipe)) {
939 prepare_outbound_urb(ep, urb->context);
941 prepare_inbound_urb(ep, urb->context);
944 err = usb_submit_urb(urb, GFP_ATOMIC);
946 usb_audio_err(ep->chip,
947 "cannot submit urb %d, error %d: %s\n",
948 i, err, usb_error_string(err));
951 set_bit(i, &ep->active_mask);
957 clear_bit(EP_FLAG_RUNNING, &ep->flags);
959 deactivate_urbs(ep, false);
964 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
966 * @ep: the endpoint to stop (may be NULL)
968 * A call to this function will decrement the use count of the endpoint.
969 * In case the last user has requested the endpoint stop, the URBs will
970 * actually be deactivated.
972 * Must be balanced to calls of snd_usb_endpoint_start().
974 * The caller needs to synchronize the pending stop operation via
975 * snd_usb_endpoint_sync_pending_stop().
977 void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep)
982 if (snd_BUG_ON(ep->use_count == 0))
985 if (--ep->use_count == 0) {
986 deactivate_urbs(ep, false);
987 ep->data_subs = NULL;
988 ep->sync_slave = NULL;
989 ep->retire_data_urb = NULL;
990 ep->prepare_data_urb = NULL;
991 set_bit(EP_FLAG_STOPPING, &ep->flags);
996 * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint
998 * @ep: the endpoint to deactivate
1000 * If the endpoint is not currently in use, this functions will
1001 * deactivate its associated URBs.
1003 * In case of any active users, this functions does nothing.
1005 void snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep)
1010 if (ep->use_count != 0)
1013 deactivate_urbs(ep, true);
1014 wait_clear_urbs(ep);
1018 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
1020 * @ep: the endpoint to release
1022 * This function does not care for the endpoint's use count but will tear
1023 * down all the streaming URBs immediately.
1025 void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
1027 release_urbs(ep, 1);
1031 * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint
1033 * @ep: the endpoint to free
1035 * This free all resources of the given ep.
1037 void snd_usb_endpoint_free(struct snd_usb_endpoint *ep)
1043 * snd_usb_handle_sync_urb: parse an USB sync packet
1045 * @ep: the endpoint to handle the packet
1046 * @sender: the sending endpoint
1047 * @urb: the received packet
1049 * This function is called from the context of an endpoint that received
1050 * the packet and is used to let another endpoint object handle the payload.
1052 void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
1053 struct snd_usb_endpoint *sender,
1054 const struct urb *urb)
1058 unsigned long flags;
1060 snd_BUG_ON(ep == sender);
1063 * In case the endpoint is operating in implicit feedback mode, prepare
1064 * a new outbound URB that has the same layout as the received packet
1065 * and add it to the list of pending urbs. queue_pending_output_urbs()
1066 * will take care of them later.
1068 if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1069 ep->use_count != 0) {
1071 /* implicit feedback case */
1073 struct snd_urb_ctx *in_ctx;
1074 struct snd_usb_packet_info *out_packet;
1076 in_ctx = urb->context;
1078 /* Count overall packet size */
1079 for (i = 0; i < in_ctx->packets; i++)
1080 if (urb->iso_frame_desc[i].status == 0)
1081 bytes += urb->iso_frame_desc[i].actual_length;
1084 * skip empty packets. At least M-Audio's Fast Track Ultra stops
1085 * streaming once it received a 0-byte OUT URB
1090 spin_lock_irqsave(&ep->lock, flags);
1091 out_packet = ep->next_packet + ep->next_packet_write_pos;
1094 * Iterate through the inbound packet and prepare the lengths
1095 * for the output packet. The OUT packet we are about to send
1096 * will have the same amount of payload bytes per stride as the
1097 * IN packet we just received. Since the actual size is scaled
1098 * by the stride, use the sender stride to calculate the length
1099 * in case the number of channels differ between the implicitly
1100 * fed-back endpoint and the synchronizing endpoint.
1103 out_packet->packets = in_ctx->packets;
1104 for (i = 0; i < in_ctx->packets; i++) {
1105 if (urb->iso_frame_desc[i].status == 0)
1106 out_packet->packet_size[i] =
1107 urb->iso_frame_desc[i].actual_length / sender->stride;
1109 out_packet->packet_size[i] = 0;
1112 ep->next_packet_write_pos++;
1113 ep->next_packet_write_pos %= MAX_URBS;
1114 spin_unlock_irqrestore(&ep->lock, flags);
1115 queue_pending_output_urbs(ep);
1121 * process after playback sync complete
1123 * Full speed devices report feedback values in 10.14 format as samples
1124 * per frame, high speed devices in 16.16 format as samples per
1127 * Because the Audio Class 1 spec was written before USB 2.0, many high
1128 * speed devices use a wrong interpretation, some others use an
1129 * entirely different format.
1131 * Therefore, we cannot predict what format any particular device uses
1132 * and must detect it automatically.
1135 if (urb->iso_frame_desc[0].status != 0 ||
1136 urb->iso_frame_desc[0].actual_length < 3)
1139 f = le32_to_cpup(urb->transfer_buffer);
1140 if (urb->iso_frame_desc[0].actual_length == 3)
1148 if (unlikely(sender->udh01_fb_quirk)) {
1150 * The TEAC UD-H01 firmware sometimes changes the feedback value
1153 if (f < ep->freqn - 0x8000)
1155 else if (f > ep->freqn + 0x8000)
1157 } else if (unlikely(ep->freqshift == INT_MIN)) {
1159 * The first time we see a feedback value, determine its format
1160 * by shifting it left or right until it matches the nominal
1161 * frequency value. This assumes that the feedback does not
1162 * differ from the nominal value more than +50% or -25%.
1165 while (f < ep->freqn - ep->freqn / 4) {
1169 while (f > ep->freqn + ep->freqn / 2) {
1173 ep->freqshift = shift;
1174 } else if (ep->freqshift >= 0)
1175 f <<= ep->freqshift;
1177 f >>= -ep->freqshift;
1179 if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {
1181 * If the frequency looks valid, set it.
1182 * This value is referred to in prepare_playback_urb().
1184 spin_lock_irqsave(&ep->lock, flags);
1186 spin_unlock_irqrestore(&ep->lock, flags);
1189 * Out of range; maybe the shift value is wrong.
1190 * Reset it so that we autodetect again the next time.
1192 ep->freqshift = INT_MIN;