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);
187 * Prepare a PLAYBACK urb for submission to the bus.
189 static void prepare_outbound_urb(struct snd_usb_endpoint *ep,
190 struct snd_urb_ctx *ctx)
193 struct urb *urb = ctx->urb;
194 unsigned char *cp = urb->transfer_buffer;
196 urb->dev = ep->chip->dev; /* we need to set this at each time */
199 case SND_USB_ENDPOINT_TYPE_DATA:
200 if (ep->prepare_data_urb) {
201 ep->prepare_data_urb(ep->data_subs, urb);
203 /* no data provider, so send silence */
204 unsigned int offs = 0;
205 for (i = 0; i < ctx->packets; ++i) {
208 if (ctx->packet_size[i])
209 counts = ctx->packet_size[i];
211 counts = snd_usb_endpoint_next_packet_size(ep);
213 urb->iso_frame_desc[i].offset = offs * ep->stride;
214 urb->iso_frame_desc[i].length = counts * ep->stride;
218 urb->number_of_packets = ctx->packets;
219 urb->transfer_buffer_length = offs * ep->stride;
220 memset(urb->transfer_buffer, ep->silence_value,
225 case SND_USB_ENDPOINT_TYPE_SYNC:
226 if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) {
228 * fill the length and offset of each urb descriptor.
229 * the fixed 12.13 frequency is passed as 16.16 through the pipe.
231 urb->iso_frame_desc[0].length = 4;
232 urb->iso_frame_desc[0].offset = 0;
234 cp[1] = ep->freqn >> 8;
235 cp[2] = ep->freqn >> 16;
236 cp[3] = ep->freqn >> 24;
239 * fill the length and offset of each urb descriptor.
240 * the fixed 10.14 frequency is passed through the pipe.
242 urb->iso_frame_desc[0].length = 3;
243 urb->iso_frame_desc[0].offset = 0;
244 cp[0] = ep->freqn >> 2;
245 cp[1] = ep->freqn >> 10;
246 cp[2] = ep->freqn >> 18;
254 * Prepare a CAPTURE or SYNC urb for submission to the bus.
256 static inline void prepare_inbound_urb(struct snd_usb_endpoint *ep,
257 struct snd_urb_ctx *urb_ctx)
260 struct urb *urb = urb_ctx->urb;
262 urb->dev = ep->chip->dev; /* we need to set this at each time */
265 case SND_USB_ENDPOINT_TYPE_DATA:
267 for (i = 0; i < urb_ctx->packets; i++) {
268 urb->iso_frame_desc[i].offset = offs;
269 urb->iso_frame_desc[i].length = ep->curpacksize;
270 offs += ep->curpacksize;
273 urb->transfer_buffer_length = offs;
274 urb->number_of_packets = urb_ctx->packets;
277 case SND_USB_ENDPOINT_TYPE_SYNC:
278 urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize);
279 urb->iso_frame_desc[0].offset = 0;
285 * Send output urbs that have been prepared previously. URBs are dequeued
286 * from ep->ready_playback_urbs and in case there there aren't any available
287 * or there are no packets that have been prepared, this function does
290 * The reason why the functionality of sending and preparing URBs is separated
291 * is that host controllers don't guarantee the order in which they return
292 * inbound and outbound packets to their submitters.
294 * This function is only used for implicit feedback endpoints. For endpoints
295 * driven by dedicated sync endpoints, URBs are immediately re-submitted
296 * from their completion handler.
298 static void queue_pending_output_urbs(struct snd_usb_endpoint *ep)
300 while (test_bit(EP_FLAG_RUNNING, &ep->flags)) {
303 struct snd_usb_packet_info *uninitialized_var(packet);
304 struct snd_urb_ctx *ctx = NULL;
308 spin_lock_irqsave(&ep->lock, flags);
309 if (ep->next_packet_read_pos != ep->next_packet_write_pos) {
310 packet = ep->next_packet + ep->next_packet_read_pos;
311 ep->next_packet_read_pos++;
312 ep->next_packet_read_pos %= MAX_URBS;
314 /* take URB out of FIFO */
315 if (!list_empty(&ep->ready_playback_urbs))
316 ctx = list_first_entry(&ep->ready_playback_urbs,
317 struct snd_urb_ctx, ready_list);
319 spin_unlock_irqrestore(&ep->lock, flags);
324 list_del_init(&ctx->ready_list);
327 /* copy over the length information */
328 for (i = 0; i < packet->packets; i++)
329 ctx->packet_size[i] = packet->packet_size[i];
331 /* call the data handler to fill in playback data */
332 prepare_outbound_urb(ep, ctx);
334 err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
336 usb_audio_err(ep->chip,
337 "Unable to submit urb #%d: %d (urb %p)\n",
338 ctx->index, err, ctx->urb);
340 set_bit(ctx->index, &ep->active_mask);
345 * complete callback for urbs
347 static void snd_complete_urb(struct urb *urb)
349 struct snd_urb_ctx *ctx = urb->context;
350 struct snd_usb_endpoint *ep = ctx->ep;
351 struct snd_pcm_substream *substream;
355 if (unlikely(urb->status == -ENOENT || /* unlinked */
356 urb->status == -ENODEV || /* device removed */
357 urb->status == -ECONNRESET || /* unlinked */
358 urb->status == -ESHUTDOWN)) /* device disabled */
360 /* device disconnected */
361 if (unlikely(atomic_read(&ep->chip->shutdown)))
364 if (usb_pipeout(ep->pipe)) {
365 retire_outbound_urb(ep, ctx);
366 /* can be stopped during retire callback */
367 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
370 if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
371 spin_lock_irqsave(&ep->lock, flags);
372 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
373 spin_unlock_irqrestore(&ep->lock, flags);
374 queue_pending_output_urbs(ep);
379 prepare_outbound_urb(ep, ctx);
381 retire_inbound_urb(ep, ctx);
382 /* can be stopped during retire callback */
383 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
386 prepare_inbound_urb(ep, ctx);
389 err = usb_submit_urb(urb, GFP_ATOMIC);
393 usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
394 if (ep->data_subs && ep->data_subs->pcm_substream) {
395 substream = ep->data_subs->pcm_substream;
396 snd_pcm_stop_xrun(substream);
400 clear_bit(ctx->index, &ep->active_mask);
404 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
407 * @alts: The USB host interface
408 * @ep_num: The number of the endpoint to use
409 * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE
410 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
412 * If the requested endpoint has not been added to the given chip before,
413 * a new instance is created. Otherwise, a pointer to the previoulsy
414 * created instance is returned. In case of any error, NULL is returned.
416 * New endpoints will be added to chip->ep_list and must be freed by
417 * calling snd_usb_endpoint_free().
419 struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip,
420 struct usb_host_interface *alts,
421 int ep_num, int direction, int type)
423 struct snd_usb_endpoint *ep;
424 int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK;
429 mutex_lock(&chip->mutex);
431 list_for_each_entry(ep, &chip->ep_list, list) {
432 if (ep->ep_num == ep_num &&
433 ep->iface == alts->desc.bInterfaceNumber &&
434 ep->altsetting == alts->desc.bAlternateSetting) {
435 usb_audio_dbg(ep->chip,
436 "Re-using EP %x in iface %d,%d @%p\n",
437 ep_num, ep->iface, ep->altsetting, ep);
442 usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n",
443 is_playback ? "playback" : "capture",
444 type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync",
447 ep = kzalloc(sizeof(*ep), GFP_KERNEL);
452 spin_lock_init(&ep->lock);
455 ep->iface = alts->desc.bInterfaceNumber;
456 ep->altsetting = alts->desc.bAlternateSetting;
457 INIT_LIST_HEAD(&ep->ready_playback_urbs);
458 ep_num &= USB_ENDPOINT_NUMBER_MASK;
461 ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
463 ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);
465 if (type == SND_USB_ENDPOINT_TYPE_SYNC) {
466 if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
467 get_endpoint(alts, 1)->bRefresh >= 1 &&
468 get_endpoint(alts, 1)->bRefresh <= 9)
469 ep->syncinterval = get_endpoint(alts, 1)->bRefresh;
470 else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
471 ep->syncinterval = 1;
472 else if (get_endpoint(alts, 1)->bInterval >= 1 &&
473 get_endpoint(alts, 1)->bInterval <= 16)
474 ep->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
476 ep->syncinterval = 3;
478 ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize);
480 if (chip->usb_id == USB_ID(0x0644, 0x8038) /* TEAC UD-H01 */ &&
481 ep->syncmaxsize == 4)
482 ep->udh01_fb_quirk = 1;
485 list_add_tail(&ep->list, &chip->ep_list);
488 mutex_unlock(&chip->mutex);
494 * wait until all urbs are processed.
496 static int wait_clear_urbs(struct snd_usb_endpoint *ep)
498 unsigned long end_time = jiffies + msecs_to_jiffies(1000);
502 alive = bitmap_weight(&ep->active_mask, ep->nurbs);
506 schedule_timeout_uninterruptible(1);
507 } while (time_before(jiffies, end_time));
510 usb_audio_err(ep->chip,
511 "timeout: still %d active urbs on EP #%x\n",
513 clear_bit(EP_FLAG_STOPPING, &ep->flags);
518 /* sync the pending stop operation;
519 * this function itself doesn't trigger the stop operation
521 void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
523 if (ep && test_bit(EP_FLAG_STOPPING, &ep->flags))
528 * unlink active urbs.
530 static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force)
534 if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */
537 clear_bit(EP_FLAG_RUNNING, &ep->flags);
539 INIT_LIST_HEAD(&ep->ready_playback_urbs);
540 ep->next_packet_read_pos = 0;
541 ep->next_packet_write_pos = 0;
543 for (i = 0; i < ep->nurbs; i++) {
544 if (test_bit(i, &ep->active_mask)) {
545 if (!test_and_set_bit(i, &ep->unlink_mask)) {
546 struct urb *u = ep->urb[i].urb;
556 * release an endpoint's urbs
558 static void release_urbs(struct snd_usb_endpoint *ep, int force)
562 /* route incoming urbs to nirvana */
563 ep->retire_data_urb = NULL;
564 ep->prepare_data_urb = NULL;
567 deactivate_urbs(ep, force);
570 for (i = 0; i < ep->nurbs; i++)
571 release_urb_ctx(&ep->urb[i]);
574 usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
575 ep->syncbuf, ep->sync_dma);
582 * configure a data endpoint
584 static int data_ep_set_params(struct snd_usb_endpoint *ep,
585 snd_pcm_format_t pcm_format,
586 unsigned int channels,
587 unsigned int period_bytes,
588 unsigned int frames_per_period,
589 unsigned int periods_per_buffer,
590 struct audioformat *fmt,
591 struct snd_usb_endpoint *sync_ep)
593 unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
594 unsigned int max_packs_per_period, urbs_per_period, urb_packs;
595 unsigned int max_urbs, i;
596 int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
598 if (pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
600 * When operating in DSD DOP mode, the size of a sample frame
601 * in hardware differs from the actual physical format width
602 * because we need to make room for the DOP markers.
604 frame_bits += channels << 3;
607 ep->datainterval = fmt->datainterval;
608 ep->stride = frame_bits >> 3;
609 ep->silence_value = pcm_format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0;
611 /* assume max. frequency is 25% higher than nominal */
612 ep->freqmax = ep->freqn + (ep->freqn >> 2);
613 /* Round up freqmax to nearest integer in order to calculate maximum
614 * packet size, which must represent a whole number of frames.
615 * This is accomplished by adding 0x0.ffff before converting the
616 * Q16.16 format into integer.
617 * In order to accurately calculate the maximum packet size when
618 * the data interval is more than 1 (i.e. ep->datainterval > 0),
619 * multiply by the data interval prior to rounding. For instance,
620 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
621 * frames with a data interval of 1, but 11 (10.25) frames with a
622 * data interval of 2.
623 * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
624 * maximum datainterval value of 3, at USB full speed, higher for
625 * USB high speed, noting that ep->freqmax is in units of
626 * frames per packet in Q16.16 format.)
628 maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
630 /* but wMaxPacketSize might reduce this */
631 if (ep->maxpacksize && ep->maxpacksize < maxsize) {
632 /* whatever fits into a max. size packet */
633 maxsize = ep->maxpacksize;
634 ep->freqmax = (maxsize / (frame_bits >> 3))
635 << (16 - ep->datainterval);
639 ep->curpacksize = ep->maxpacksize;
641 ep->curpacksize = maxsize;
643 if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
644 packs_per_ms = 8 >> ep->datainterval;
645 max_packs_per_urb = MAX_PACKS_HS;
648 max_packs_per_urb = MAX_PACKS;
650 if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep))
651 max_packs_per_urb = min(max_packs_per_urb,
652 1U << sync_ep->syncinterval);
653 max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);
656 * Capture endpoints need to use small URBs because there's no way
657 * to tell in advance where the next period will end, and we don't
658 * want the next URB to complete much after the period ends.
660 * Playback endpoints with implicit sync much use the same parameters
661 * as their corresponding capture endpoint.
663 if (usb_pipein(ep->pipe) ||
664 snd_usb_endpoint_implicit_feedback_sink(ep)) {
666 urb_packs = packs_per_ms;
668 * Wireless devices can poll at a max rate of once per 4ms.
669 * For dataintervals less than 5, increase the packet count to
670 * allow the host controller to use bursting to fill in the
673 if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_WIRELESS) {
674 int interval = ep->datainterval;
675 while (interval < 5) {
680 /* make capture URBs <= 1 ms and smaller than a period */
681 urb_packs = min(max_packs_per_urb, urb_packs);
682 while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
684 ep->nurbs = MAX_URBS;
687 * Playback endpoints without implicit sync are adjusted so that
688 * a period fits as evenly as possible in the smallest number of
689 * URBs. The total number of URBs is adjusted to the size of the
690 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
693 /* determine how small a packet can be */
694 minsize = (ep->freqn >> (16 - ep->datainterval)) *
696 /* with sync from device, assume it can be 12% lower */
698 minsize -= minsize >> 3;
699 minsize = max(minsize, 1u);
701 /* how many packets will contain an entire ALSA period? */
702 max_packs_per_period = DIV_ROUND_UP(period_bytes, minsize);
704 /* how many URBs will contain a period? */
705 urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
707 /* how many packets are needed in each URB? */
708 urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);
710 /* limit the number of frames in a single URB */
711 ep->max_urb_frames = DIV_ROUND_UP(frames_per_period,
714 /* try to use enough URBs to contain an entire ALSA buffer */
715 max_urbs = min((unsigned) MAX_URBS,
716 MAX_QUEUE * packs_per_ms / urb_packs);
717 ep->nurbs = min(max_urbs, urbs_per_period * periods_per_buffer);
720 /* allocate and initialize data urbs */
721 for (i = 0; i < ep->nurbs; i++) {
722 struct snd_urb_ctx *u = &ep->urb[i];
725 u->packets = urb_packs;
726 u->buffer_size = maxsize * u->packets;
728 if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
729 u->packets++; /* for transfer delimiter */
730 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
734 u->urb->transfer_buffer =
735 usb_alloc_coherent(ep->chip->dev, u->buffer_size,
736 GFP_KERNEL, &u->urb->transfer_dma);
737 if (!u->urb->transfer_buffer)
739 u->urb->pipe = ep->pipe;
740 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
741 u->urb->interval = 1 << ep->datainterval;
743 u->urb->complete = snd_complete_urb;
744 INIT_LIST_HEAD(&u->ready_list);
755 * configure a sync endpoint
757 static int sync_ep_set_params(struct snd_usb_endpoint *ep)
761 ep->syncbuf = usb_alloc_coherent(ep->chip->dev, SYNC_URBS * 4,
762 GFP_KERNEL, &ep->sync_dma);
766 for (i = 0; i < SYNC_URBS; i++) {
767 struct snd_urb_ctx *u = &ep->urb[i];
771 u->urb = usb_alloc_urb(1, GFP_KERNEL);
774 u->urb->transfer_buffer = ep->syncbuf + i * 4;
775 u->urb->transfer_dma = ep->sync_dma + i * 4;
776 u->urb->transfer_buffer_length = 4;
777 u->urb->pipe = ep->pipe;
778 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
779 u->urb->number_of_packets = 1;
780 u->urb->interval = 1 << ep->syncinterval;
782 u->urb->complete = snd_complete_urb;
785 ep->nurbs = SYNC_URBS;
795 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
797 * @ep: the snd_usb_endpoint to configure
798 * @pcm_format: the audio fomat.
799 * @channels: the number of audio channels.
800 * @period_bytes: the number of bytes in one alsa period.
801 * @period_frames: the number of frames in one alsa period.
802 * @buffer_periods: the number of periods in one alsa buffer.
803 * @rate: the frame rate.
804 * @fmt: the USB audio format information
805 * @sync_ep: the sync endpoint to use, if any
807 * Determine the number of URBs to be used on this endpoint.
808 * An endpoint must be configured before it can be started.
809 * An endpoint that is already running can not be reconfigured.
811 int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
812 snd_pcm_format_t pcm_format,
813 unsigned int channels,
814 unsigned int period_bytes,
815 unsigned int period_frames,
816 unsigned int buffer_periods,
818 struct audioformat *fmt,
819 struct snd_usb_endpoint *sync_ep)
823 if (ep->use_count != 0) {
824 usb_audio_warn(ep->chip,
825 "Unable to change format on ep #%x: already in use\n",
830 /* release old buffers, if any */
833 ep->datainterval = fmt->datainterval;
834 ep->maxpacksize = fmt->maxpacksize;
835 ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
837 if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL)
838 ep->freqn = get_usb_full_speed_rate(rate);
840 ep->freqn = get_usb_high_speed_rate(rate);
842 /* calculate the frequency in 16.16 format */
843 ep->freqm = ep->freqn;
844 ep->freqshift = INT_MIN;
849 case SND_USB_ENDPOINT_TYPE_DATA:
850 err = data_ep_set_params(ep, pcm_format, channels,
851 period_bytes, period_frames,
852 buffer_periods, fmt, sync_ep);
854 case SND_USB_ENDPOINT_TYPE_SYNC:
855 err = sync_ep_set_params(ep);
861 usb_audio_dbg(ep->chip,
862 "Setting params for ep #%x (type %d, %d urbs), ret=%d\n",
863 ep->ep_num, ep->type, ep->nurbs, err);
869 * snd_usb_endpoint_start: start an snd_usb_endpoint
871 * @ep: the endpoint to start
872 * @can_sleep: flag indicating whether the operation is executed in
875 * A call to this function will increment the use count of the endpoint.
876 * In case it is not already running, the URBs for this endpoint will be
877 * submitted. Otherwise, this function does nothing.
879 * Must be balanced to calls of snd_usb_endpoint_stop().
881 * Returns an error if the URB submission failed, 0 in all other cases.
883 int snd_usb_endpoint_start(struct snd_usb_endpoint *ep, bool can_sleep)
888 if (atomic_read(&ep->chip->shutdown))
891 /* already running? */
892 if (++ep->use_count != 1)
895 /* just to be sure */
896 deactivate_urbs(ep, false);
904 snd_usb_endpoint_start_quirk(ep);
907 * If this endpoint has a data endpoint as implicit feedback source,
908 * don't start the urbs here. Instead, mark them all as available,
909 * wait for the record urbs to return and queue the playback urbs
913 set_bit(EP_FLAG_RUNNING, &ep->flags);
915 if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
916 for (i = 0; i < ep->nurbs; i++) {
917 struct snd_urb_ctx *ctx = ep->urb + i;
918 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
924 for (i = 0; i < ep->nurbs; i++) {
925 struct urb *urb = ep->urb[i].urb;
927 if (snd_BUG_ON(!urb))
930 if (usb_pipeout(ep->pipe)) {
931 prepare_outbound_urb(ep, urb->context);
933 prepare_inbound_urb(ep, urb->context);
936 err = usb_submit_urb(urb, GFP_ATOMIC);
938 usb_audio_err(ep->chip,
939 "cannot submit urb %d, error %d: %s\n",
940 i, err, usb_error_string(err));
943 set_bit(i, &ep->active_mask);
949 clear_bit(EP_FLAG_RUNNING, &ep->flags);
951 deactivate_urbs(ep, false);
956 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
958 * @ep: the endpoint to stop (may be NULL)
960 * A call to this function will decrement the use count of the endpoint.
961 * In case the last user has requested the endpoint stop, the URBs will
962 * actually be deactivated.
964 * Must be balanced to calls of snd_usb_endpoint_start().
966 * The caller needs to synchronize the pending stop operation via
967 * snd_usb_endpoint_sync_pending_stop().
969 void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep)
974 if (snd_BUG_ON(ep->use_count == 0))
977 if (--ep->use_count == 0) {
978 deactivate_urbs(ep, false);
979 ep->data_subs = NULL;
980 ep->sync_slave = NULL;
981 ep->retire_data_urb = NULL;
982 ep->prepare_data_urb = NULL;
983 set_bit(EP_FLAG_STOPPING, &ep->flags);
988 * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint
990 * @ep: the endpoint to deactivate
992 * If the endpoint is not currently in use, this functions will
993 * deactivate its associated URBs.
995 * In case of any active users, this functions does nothing.
997 void snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep)
1002 if (ep->use_count != 0)
1005 deactivate_urbs(ep, true);
1006 wait_clear_urbs(ep);
1010 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
1012 * @ep: the endpoint to release
1014 * This function does not care for the endpoint's use count but will tear
1015 * down all the streaming URBs immediately.
1017 void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
1019 release_urbs(ep, 1);
1023 * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint
1025 * @ep: the endpoint to free
1027 * This free all resources of the given ep.
1029 void snd_usb_endpoint_free(struct snd_usb_endpoint *ep)
1035 * snd_usb_handle_sync_urb: parse an USB sync packet
1037 * @ep: the endpoint to handle the packet
1038 * @sender: the sending endpoint
1039 * @urb: the received packet
1041 * This function is called from the context of an endpoint that received
1042 * the packet and is used to let another endpoint object handle the payload.
1044 void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
1045 struct snd_usb_endpoint *sender,
1046 const struct urb *urb)
1050 unsigned long flags;
1052 snd_BUG_ON(ep == sender);
1055 * In case the endpoint is operating in implicit feedback mode, prepare
1056 * a new outbound URB that has the same layout as the received packet
1057 * and add it to the list of pending urbs. queue_pending_output_urbs()
1058 * will take care of them later.
1060 if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1061 ep->use_count != 0) {
1063 /* implicit feedback case */
1065 struct snd_urb_ctx *in_ctx;
1066 struct snd_usb_packet_info *out_packet;
1068 in_ctx = urb->context;
1070 /* Count overall packet size */
1071 for (i = 0; i < in_ctx->packets; i++)
1072 if (urb->iso_frame_desc[i].status == 0)
1073 bytes += urb->iso_frame_desc[i].actual_length;
1076 * skip empty packets. At least M-Audio's Fast Track Ultra stops
1077 * streaming once it received a 0-byte OUT URB
1082 spin_lock_irqsave(&ep->lock, flags);
1083 out_packet = ep->next_packet + ep->next_packet_write_pos;
1086 * Iterate through the inbound packet and prepare the lengths
1087 * for the output packet. The OUT packet we are about to send
1088 * will have the same amount of payload bytes per stride as the
1089 * IN packet we just received. Since the actual size is scaled
1090 * by the stride, use the sender stride to calculate the length
1091 * in case the number of channels differ between the implicitly
1092 * fed-back endpoint and the synchronizing endpoint.
1095 out_packet->packets = in_ctx->packets;
1096 for (i = 0; i < in_ctx->packets; i++) {
1097 if (urb->iso_frame_desc[i].status == 0)
1098 out_packet->packet_size[i] =
1099 urb->iso_frame_desc[i].actual_length / sender->stride;
1101 out_packet->packet_size[i] = 0;
1104 ep->next_packet_write_pos++;
1105 ep->next_packet_write_pos %= MAX_URBS;
1106 spin_unlock_irqrestore(&ep->lock, flags);
1107 queue_pending_output_urbs(ep);
1113 * process after playback sync complete
1115 * Full speed devices report feedback values in 10.14 format as samples
1116 * per frame, high speed devices in 16.16 format as samples per
1119 * Because the Audio Class 1 spec was written before USB 2.0, many high
1120 * speed devices use a wrong interpretation, some others use an
1121 * entirely different format.
1123 * Therefore, we cannot predict what format any particular device uses
1124 * and must detect it automatically.
1127 if (urb->iso_frame_desc[0].status != 0 ||
1128 urb->iso_frame_desc[0].actual_length < 3)
1131 f = le32_to_cpup(urb->transfer_buffer);
1132 if (urb->iso_frame_desc[0].actual_length == 3)
1140 if (unlikely(sender->udh01_fb_quirk)) {
1142 * The TEAC UD-H01 firmware sometimes changes the feedback value
1145 if (f < ep->freqn - 0x8000)
1147 else if (f > ep->freqn + 0x8000)
1149 } else if (unlikely(ep->freqshift == INT_MIN)) {
1151 * The first time we see a feedback value, determine its format
1152 * by shifting it left or right until it matches the nominal
1153 * frequency value. This assumes that the feedback does not
1154 * differ from the nominal value more than +50% or -25%.
1157 while (f < ep->freqn - ep->freqn / 4) {
1161 while (f > ep->freqn + ep->freqn / 2) {
1165 ep->freqshift = shift;
1166 } else if (ep->freqshift >= 0)
1167 f <<= ep->freqshift;
1169 f >>= -ep->freqshift;
1171 if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {
1173 * If the frequency looks valid, set it.
1174 * This value is referred to in prepare_playback_urb().
1176 spin_lock_irqsave(&ep->lock, flags);
1178 spin_unlock_irqrestore(&ep->lock, flags);
1181 * Out of range; maybe the shift value is wrong.
1182 * Reset it so that we autodetect again the next time.
1184 ep->freqshift = INT_MIN;