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TOMOYO Linux Cross Reference
Linux/sound/usb/endpoint.c

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Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  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.
  6  *
  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.
 11  *
 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
 15  *
 16  */
 17 
 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>
 24 
 25 #include <sound/core.h>
 26 #include <sound/pcm.h>
 27 #include <sound/pcm_params.h>
 28 
 29 #include "usbaudio.h"
 30 #include "helper.h"
 31 #include "card.h"
 32 #include "endpoint.h"
 33 #include "pcm.h"
 34 #include "quirks.h"
 35 
 36 #define EP_FLAG_RUNNING         1
 37 #define EP_FLAG_STOPPING        2
 38 
 39 /*
 40  * snd_usb_endpoint is a model that abstracts everything related to an
 41  * USB endpoint and its streaming.
 42  *
 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.
 47  *
 48  * There are two different types of endpoints in audio applications.
 49  *
 50  * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both
 51  * inbound and outbound traffic.
 52  *
 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
 55  * (3 or 4 bytes).
 56  *
 57  * Each endpoint has to be configured prior to being used by calling
 58  * snd_usb_endpoint_set_params().
 59  *
 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.
 64  */
 65 
 66 /*
 67  * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
 68  * this will overflow at approx 524 kHz
 69  */
 70 static inline unsigned get_usb_full_speed_rate(unsigned int rate)
 71 {
 72         return ((rate << 13) + 62) / 125;
 73 }
 74 
 75 /*
 76  * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
 77  * this will overflow at approx 4 MHz
 78  */
 79 static inline unsigned get_usb_high_speed_rate(unsigned int rate)
 80 {
 81         return ((rate << 10) + 62) / 125;
 82 }
 83 
 84 /*
 85  * release a urb data
 86  */
 87 static void release_urb_ctx(struct snd_urb_ctx *u)
 88 {
 89         if (u->buffer_size)
 90                 usb_free_coherent(u->ep->chip->dev, u->buffer_size,
 91                                   u->urb->transfer_buffer,
 92                                   u->urb->transfer_dma);
 93         usb_free_urb(u->urb);
 94         u->urb = NULL;
 95 }
 96 
 97 static const char *usb_error_string(int err)
 98 {
 99         switch (err) {
100         case -ENODEV:
101                 return "no device";
102         case -ENOENT:
103                 return "endpoint not enabled";
104         case -EPIPE:
105                 return "endpoint stalled";
106         case -ENOSPC:
107                 return "not enough bandwidth";
108         case -ESHUTDOWN:
109                 return "device disabled";
110         case -EHOSTUNREACH:
111                 return "device suspended";
112         case -EINVAL:
113         case -EAGAIN:
114         case -EFBIG:
115         case -EMSGSIZE:
116                 return "internal error";
117         default:
118                 return "unknown error";
119         }
120 }
121 
122 /**
123  * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type
124  *
125  * @ep: The snd_usb_endpoint
126  *
127  * Determine whether an endpoint is driven by an implicit feedback
128  * data endpoint source.
129  */
130 int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep)
131 {
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);
136 }
137 
138 /*
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.
142  *
143  * For implicit feedback, next_packet_size() is unused.
144  */
145 int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep)
146 {
147         unsigned long flags;
148         int ret;
149 
150         if (ep->fill_max)
151                 return ep->maxframesize;
152 
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);
158 
159         return ret;
160 }
161 
162 static void retire_outbound_urb(struct snd_usb_endpoint *ep,
163                                 struct snd_urb_ctx *urb_ctx)
164 {
165         if (ep->retire_data_urb)
166                 ep->retire_data_urb(ep->data_subs, urb_ctx->urb);
167 }
168 
169 static void retire_inbound_urb(struct snd_usb_endpoint *ep,
170                                struct snd_urb_ctx *urb_ctx)
171 {
172         struct urb *urb = urb_ctx->urb;
173 
174         if (unlikely(ep->skip_packets > 0)) {
175                 ep->skip_packets--;
176                 return;
177         }
178 
179         if (ep->sync_slave)
180                 snd_usb_handle_sync_urb(ep->sync_slave, ep, urb);
181 
182         if (ep->retire_data_urb)
183                 ep->retire_data_urb(ep->data_subs, urb);
184 }
185 
186 static void prepare_silent_urb(struct snd_usb_endpoint *ep,
187                                struct snd_urb_ctx *ctx)
188 {
189         struct urb *urb = ctx->urb;
190         unsigned int offs = 0;
191         unsigned int extra = 0;
192         __le32 packet_length;
193         int i;
194 
195         /* For tx_length_quirk, put packet length at start of packet */
196         if (ep->chip->tx_length_quirk)
197                 extra = sizeof(packet_length);
198 
199         for (i = 0; i < ctx->packets; ++i) {
200                 unsigned int offset;
201                 unsigned int length;
202                 int counts;
203 
204                 if (ctx->packet_size[i])
205                         counts = ctx->packet_size[i];
206                 else
207                         counts = snd_usb_endpoint_next_packet_size(ep);
208 
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;
213                 if (extra) {
214                         packet_length = cpu_to_le32(length);
215                         memcpy(urb->transfer_buffer + offset,
216                                &packet_length, sizeof(packet_length));
217                 }
218                 memset(urb->transfer_buffer + offset + extra,
219                        ep->silence_value, length);
220                 offs += counts;
221         }
222 
223         urb->number_of_packets = ctx->packets;
224         urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra;
225 }
226 
227 /*
228  * Prepare a PLAYBACK urb for submission to the bus.
229  */
230 static void prepare_outbound_urb(struct snd_usb_endpoint *ep,
231                                  struct snd_urb_ctx *ctx)
232 {
233         struct urb *urb = ctx->urb;
234         unsigned char *cp = urb->transfer_buffer;
235 
236         urb->dev = ep->chip->dev; /* we need to set this at each time */
237 
238         switch (ep->type) {
239         case SND_USB_ENDPOINT_TYPE_DATA:
240                 if (ep->prepare_data_urb) {
241                         ep->prepare_data_urb(ep->data_subs, urb);
242                 } else {
243                         /* no data provider, so send silence */
244                         prepare_silent_urb(ep, ctx);
245                 }
246                 break;
247 
248         case SND_USB_ENDPOINT_TYPE_SYNC:
249                 if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) {
250                         /*
251                          * fill the length and offset of each urb descriptor.
252                          * the fixed 12.13 frequency is passed as 16.16 through the pipe.
253                          */
254                         urb->iso_frame_desc[0].length = 4;
255                         urb->iso_frame_desc[0].offset = 0;
256                         cp[0] = ep->freqn;
257                         cp[1] = ep->freqn >> 8;
258                         cp[2] = ep->freqn >> 16;
259                         cp[3] = ep->freqn >> 24;
260                 } else {
261                         /*
262                          * fill the length and offset of each urb descriptor.
263                          * the fixed 10.14 frequency is passed through the pipe.
264                          */
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;
270                 }
271 
272                 break;
273         }
274 }
275 
276 /*
277  * Prepare a CAPTURE or SYNC urb for submission to the bus.
278  */
279 static inline void prepare_inbound_urb(struct snd_usb_endpoint *ep,
280                                        struct snd_urb_ctx *urb_ctx)
281 {
282         int i, offs;
283         struct urb *urb = urb_ctx->urb;
284 
285         urb->dev = ep->chip->dev; /* we need to set this at each time */
286 
287         switch (ep->type) {
288         case SND_USB_ENDPOINT_TYPE_DATA:
289                 offs = 0;
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;
294                 }
295 
296                 urb->transfer_buffer_length = offs;
297                 urb->number_of_packets = urb_ctx->packets;
298                 break;
299 
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;
303                 break;
304         }
305 }
306 
307 /*
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
311  * nothing.
312  *
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.
316  *
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.
320  */
321 static void queue_pending_output_urbs(struct snd_usb_endpoint *ep)
322 {
323         while (test_bit(EP_FLAG_RUNNING, &ep->flags)) {
324 
325                 unsigned long flags;
326                 struct snd_usb_packet_info *uninitialized_var(packet);
327                 struct snd_urb_ctx *ctx = NULL;
328                 struct urb *urb;
329                 int err, i;
330 
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;
336 
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);
341                 }
342                 spin_unlock_irqrestore(&ep->lock, flags);
343 
344                 if (ctx == NULL)
345                         return;
346 
347                 list_del_init(&ctx->ready_list);
348                 urb = ctx->urb;
349 
350                 /* copy over the length information */
351                 for (i = 0; i < packet->packets; i++)
352                         ctx->packet_size[i] = packet->packet_size[i];
353 
354                 /* call the data handler to fill in playback data */
355                 prepare_outbound_urb(ep, ctx);
356 
357                 err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
358                 if (err < 0)
359                         usb_audio_err(ep->chip,
360                                 "Unable to submit urb #%d: %d (urb %p)\n",
361                                 ctx->index, err, ctx->urb);
362                 else
363                         set_bit(ctx->index, &ep->active_mask);
364         }
365 }
366 
367 /*
368  * complete callback for urbs
369  */
370 static void snd_complete_urb(struct urb *urb)
371 {
372         struct snd_urb_ctx *ctx = urb->context;
373         struct snd_usb_endpoint *ep = ctx->ep;
374         struct snd_pcm_substream *substream;
375         unsigned long flags;
376         int err;
377 
378         if (unlikely(urb->status == -ENOENT ||          /* unlinked */
379                      urb->status == -ENODEV ||          /* device removed */
380                      urb->status == -ECONNRESET ||      /* unlinked */
381                      urb->status == -ESHUTDOWN))        /* device disabled */
382                 goto exit_clear;
383         /* device disconnected */
384         if (unlikely(atomic_read(&ep->chip->shutdown)))
385                 goto exit_clear;
386 
387         if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
388                 goto exit_clear;
389 
390         if (usb_pipeout(ep->pipe)) {
391                 retire_outbound_urb(ep, ctx);
392                 /* can be stopped during retire callback */
393                 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
394                         goto exit_clear;
395 
396                 if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
397                         spin_lock_irqsave(&ep->lock, flags);
398                         list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
399                         spin_unlock_irqrestore(&ep->lock, flags);
400                         queue_pending_output_urbs(ep);
401 
402                         goto exit_clear;
403                 }
404 
405                 prepare_outbound_urb(ep, ctx);
406         } else {
407                 retire_inbound_urb(ep, ctx);
408                 /* can be stopped during retire callback */
409                 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
410                         goto exit_clear;
411 
412                 prepare_inbound_urb(ep, ctx);
413         }
414 
415         err = usb_submit_urb(urb, GFP_ATOMIC);
416         if (err == 0)
417                 return;
418 
419         usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
420         if (ep->data_subs && ep->data_subs->pcm_substream) {
421                 substream = ep->data_subs->pcm_substream;
422                 snd_pcm_stop_xrun(substream);
423         }
424 
425 exit_clear:
426         clear_bit(ctx->index, &ep->active_mask);
427 }
428 
429 /**
430  * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
431  *
432  * @chip: The chip
433  * @alts: The USB host interface
434  * @ep_num: The number of the endpoint to use
435  * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE
436  * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
437  *
438  * If the requested endpoint has not been added to the given chip before,
439  * a new instance is created. Otherwise, a pointer to the previoulsy
440  * created instance is returned. In case of any error, NULL is returned.
441  *
442  * New endpoints will be added to chip->ep_list and must be freed by
443  * calling snd_usb_endpoint_free().
444  *
445  * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
446  * bNumEndpoints > 1 beforehand.
447  */
448 struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip,
449                                               struct usb_host_interface *alts,
450                                               int ep_num, int direction, int type)
451 {
452         struct snd_usb_endpoint *ep;
453         int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK;
454 
455         if (WARN_ON(!alts))
456                 return NULL;
457 
458         mutex_lock(&chip->mutex);
459 
460         list_for_each_entry(ep, &chip->ep_list, list) {
461                 if (ep->ep_num == ep_num &&
462                     ep->iface == alts->desc.bInterfaceNumber &&
463                     ep->altsetting == alts->desc.bAlternateSetting) {
464                         usb_audio_dbg(ep->chip,
465                                       "Re-using EP %x in iface %d,%d @%p\n",
466                                         ep_num, ep->iface, ep->altsetting, ep);
467                         goto __exit_unlock;
468                 }
469         }
470 
471         usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n",
472                     is_playback ? "playback" : "capture",
473                     type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync",
474                     ep_num);
475 
476         ep = kzalloc(sizeof(*ep), GFP_KERNEL);
477         if (!ep)
478                 goto __exit_unlock;
479 
480         ep->chip = chip;
481         spin_lock_init(&ep->lock);
482         ep->type = type;
483         ep->ep_num = ep_num;
484         ep->iface = alts->desc.bInterfaceNumber;
485         ep->altsetting = alts->desc.bAlternateSetting;
486         INIT_LIST_HEAD(&ep->ready_playback_urbs);
487         ep_num &= USB_ENDPOINT_NUMBER_MASK;
488 
489         if (is_playback)
490                 ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
491         else
492                 ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);
493 
494         if (type == SND_USB_ENDPOINT_TYPE_SYNC) {
495                 if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
496                     get_endpoint(alts, 1)->bRefresh >= 1 &&
497                     get_endpoint(alts, 1)->bRefresh <= 9)
498                         ep->syncinterval = get_endpoint(alts, 1)->bRefresh;
499                 else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
500                         ep->syncinterval = 1;
501                 else if (get_endpoint(alts, 1)->bInterval >= 1 &&
502                          get_endpoint(alts, 1)->bInterval <= 16)
503                         ep->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
504                 else
505                         ep->syncinterval = 3;
506 
507                 ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize);
508         }
509 
510         list_add_tail(&ep->list, &chip->ep_list);
511 
512 __exit_unlock:
513         mutex_unlock(&chip->mutex);
514 
515         return ep;
516 }
517 
518 /*
519  *  wait until all urbs are processed.
520  */
521 static int wait_clear_urbs(struct snd_usb_endpoint *ep)
522 {
523         unsigned long end_time = jiffies + msecs_to_jiffies(1000);
524         int alive;
525 
526         do {
527                 alive = bitmap_weight(&ep->active_mask, ep->nurbs);
528                 if (!alive)
529                         break;
530 
531                 schedule_timeout_uninterruptible(1);
532         } while (time_before(jiffies, end_time));
533 
534         if (alive)
535                 usb_audio_err(ep->chip,
536                         "timeout: still %d active urbs on EP #%x\n",
537                         alive, ep->ep_num);
538         clear_bit(EP_FLAG_STOPPING, &ep->flags);
539 
540         ep->data_subs = NULL;
541         ep->sync_slave = NULL;
542         ep->retire_data_urb = NULL;
543         ep->prepare_data_urb = NULL;
544 
545         return 0;
546 }
547 
548 /* sync the pending stop operation;
549  * this function itself doesn't trigger the stop operation
550  */
551 void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
552 {
553         if (ep && test_bit(EP_FLAG_STOPPING, &ep->flags))
554                 wait_clear_urbs(ep);
555 }
556 
557 /*
558  * unlink active urbs.
559  */
560 static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force)
561 {
562         unsigned int i;
563 
564         if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */
565                 return -EBADFD;
566 
567         clear_bit(EP_FLAG_RUNNING, &ep->flags);
568 
569         INIT_LIST_HEAD(&ep->ready_playback_urbs);
570         ep->next_packet_read_pos = 0;
571         ep->next_packet_write_pos = 0;
572 
573         for (i = 0; i < ep->nurbs; i++) {
574                 if (test_bit(i, &ep->active_mask)) {
575                         if (!test_and_set_bit(i, &ep->unlink_mask)) {
576                                 struct urb *u = ep->urb[i].urb;
577                                 usb_unlink_urb(u);
578                         }
579                 }
580         }
581 
582         return 0;
583 }
584 
585 /*
586  * release an endpoint's urbs
587  */
588 static void release_urbs(struct snd_usb_endpoint *ep, int force)
589 {
590         int i;
591 
592         /* route incoming urbs to nirvana */
593         ep->retire_data_urb = NULL;
594         ep->prepare_data_urb = NULL;
595 
596         /* stop urbs */
597         deactivate_urbs(ep, force);
598         wait_clear_urbs(ep);
599 
600         for (i = 0; i < ep->nurbs; i++)
601                 release_urb_ctx(&ep->urb[i]);
602 
603         if (ep->syncbuf)
604                 usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
605                                   ep->syncbuf, ep->sync_dma);
606 
607         ep->syncbuf = NULL;
608         ep->nurbs = 0;
609 }
610 
611 /*
612  * configure a data endpoint
613  */
614 static int data_ep_set_params(struct snd_usb_endpoint *ep,
615                               snd_pcm_format_t pcm_format,
616                               unsigned int channels,
617                               unsigned int period_bytes,
618                               unsigned int frames_per_period,
619                               unsigned int periods_per_buffer,
620                               struct audioformat *fmt,
621                               struct snd_usb_endpoint *sync_ep)
622 {
623         unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
624         unsigned int max_packs_per_period, urbs_per_period, urb_packs;
625         unsigned int max_urbs, i;
626         int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
627         int tx_length_quirk = (ep->chip->tx_length_quirk &&
628                                usb_pipeout(ep->pipe));
629 
630         if (pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
631                 /*
632                  * When operating in DSD DOP mode, the size of a sample frame
633                  * in hardware differs from the actual physical format width
634                  * because we need to make room for the DOP markers.
635                  */
636                 frame_bits += channels << 3;
637         }
638 
639         ep->datainterval = fmt->datainterval;
640         ep->stride = frame_bits >> 3;
641 
642         switch (pcm_format) {
643         case SNDRV_PCM_FORMAT_U8:
644                 ep->silence_value = 0x80;
645                 break;
646         case SNDRV_PCM_FORMAT_DSD_U8:
647         case SNDRV_PCM_FORMAT_DSD_U16_LE:
648         case SNDRV_PCM_FORMAT_DSD_U32_LE:
649         case SNDRV_PCM_FORMAT_DSD_U16_BE:
650         case SNDRV_PCM_FORMAT_DSD_U32_BE:
651                 ep->silence_value = 0x69;
652                 break;
653         default:
654                 ep->silence_value = 0;
655         }
656 
657         /* assume max. frequency is 50% higher than nominal */
658         ep->freqmax = ep->freqn + (ep->freqn >> 1);
659         /* Round up freqmax to nearest integer in order to calculate maximum
660          * packet size, which must represent a whole number of frames.
661          * This is accomplished by adding 0x0.ffff before converting the
662          * Q16.16 format into integer.
663          * In order to accurately calculate the maximum packet size when
664          * the data interval is more than 1 (i.e. ep->datainterval > 0),
665          * multiply by the data interval prior to rounding. For instance,
666          * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
667          * frames with a data interval of 1, but 11 (10.25) frames with a
668          * data interval of 2.
669          * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
670          * maximum datainterval value of 3, at USB full speed, higher for
671          * USB high speed, noting that ep->freqmax is in units of
672          * frames per packet in Q16.16 format.)
673          */
674         maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
675                          (frame_bits >> 3);
676         if (tx_length_quirk)
677                 maxsize += sizeof(__le32); /* Space for length descriptor */
678         /* but wMaxPacketSize might reduce this */
679         if (ep->maxpacksize && ep->maxpacksize < maxsize) {
680                 /* whatever fits into a max. size packet */
681                 unsigned int data_maxsize = maxsize = ep->maxpacksize;
682 
683                 if (tx_length_quirk)
684                         /* Need to remove the length descriptor to calc freq */
685                         data_maxsize -= sizeof(__le32);
686                 ep->freqmax = (data_maxsize / (frame_bits >> 3))
687                                 << (16 - ep->datainterval);
688         }
689 
690         if (ep->fill_max)
691                 ep->curpacksize = ep->maxpacksize;
692         else
693                 ep->curpacksize = maxsize;
694 
695         if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
696                 packs_per_ms = 8 >> ep->datainterval;
697                 max_packs_per_urb = MAX_PACKS_HS;
698         } else {
699                 packs_per_ms = 1;
700                 max_packs_per_urb = MAX_PACKS;
701         }
702         if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep))
703                 max_packs_per_urb = min(max_packs_per_urb,
704                                         1U << sync_ep->syncinterval);
705         max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);
706 
707         /*
708          * Capture endpoints need to use small URBs because there's no way
709          * to tell in advance where the next period will end, and we don't
710          * want the next URB to complete much after the period ends.
711          *
712          * Playback endpoints with implicit sync much use the same parameters
713          * as their corresponding capture endpoint.
714          */
715         if (usb_pipein(ep->pipe) ||
716                         snd_usb_endpoint_implicit_feedback_sink(ep)) {
717 
718                 urb_packs = packs_per_ms;
719                 /*
720                  * Wireless devices can poll at a max rate of once per 4ms.
721                  * For dataintervals less than 5, increase the packet count to
722                  * allow the host controller to use bursting to fill in the
723                  * gaps.
724                  */
725                 if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_WIRELESS) {
726                         int interval = ep->datainterval;
727                         while (interval < 5) {
728                                 urb_packs <<= 1;
729                                 ++interval;
730                         }
731                 }
732                 /* make capture URBs <= 1 ms and smaller than a period */
733                 urb_packs = min(max_packs_per_urb, urb_packs);
734                 while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
735                         urb_packs >>= 1;
736                 ep->nurbs = MAX_URBS;
737 
738         /*
739          * Playback endpoints without implicit sync are adjusted so that
740          * a period fits as evenly as possible in the smallest number of
741          * URBs.  The total number of URBs is adjusted to the size of the
742          * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
743          */
744         } else {
745                 /* determine how small a packet can be */
746                 minsize = (ep->freqn >> (16 - ep->datainterval)) *
747                                 (frame_bits >> 3);
748                 /* with sync from device, assume it can be 12% lower */
749                 if (sync_ep)
750                         minsize -= minsize >> 3;
751                 minsize = max(minsize, 1u);
752 
753                 /* how many packets will contain an entire ALSA period? */
754                 max_packs_per_period = DIV_ROUND_UP(period_bytes, minsize);
755 
756                 /* how many URBs will contain a period? */
757                 urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
758                                 max_packs_per_urb);
759                 /* how many packets are needed in each URB? */
760                 urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);
761 
762                 /* limit the number of frames in a single URB */
763                 ep->max_urb_frames = DIV_ROUND_UP(frames_per_period,
764                                         urbs_per_period);
765 
766                 /* try to use enough URBs to contain an entire ALSA buffer */
767                 max_urbs = min((unsigned) MAX_URBS,
768                                 MAX_QUEUE * packs_per_ms / urb_packs);
769                 ep->nurbs = min(max_urbs, urbs_per_period * periods_per_buffer);
770         }
771 
772         /* allocate and initialize data urbs */
773         for (i = 0; i < ep->nurbs; i++) {
774                 struct snd_urb_ctx *u = &ep->urb[i];
775                 u->index = i;
776                 u->ep = ep;
777                 u->packets = urb_packs;
778                 u->buffer_size = maxsize * u->packets;
779 
780                 if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
781                         u->packets++; /* for transfer delimiter */
782                 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
783                 if (!u->urb)
784                         goto out_of_memory;
785 
786                 u->urb->transfer_buffer =
787                         usb_alloc_coherent(ep->chip->dev, u->buffer_size,
788                                            GFP_KERNEL, &u->urb->transfer_dma);
789                 if (!u->urb->transfer_buffer)
790                         goto out_of_memory;
791                 u->urb->pipe = ep->pipe;
792                 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
793                 u->urb->interval = 1 << ep->datainterval;
794                 u->urb->context = u;
795                 u->urb->complete = snd_complete_urb;
796                 INIT_LIST_HEAD(&u->ready_list);
797         }
798 
799         return 0;
800 
801 out_of_memory:
802         release_urbs(ep, 0);
803         return -ENOMEM;
804 }
805 
806 /*
807  * configure a sync endpoint
808  */
809 static int sync_ep_set_params(struct snd_usb_endpoint *ep)
810 {
811         int i;
812 
813         ep->syncbuf = usb_alloc_coherent(ep->chip->dev, SYNC_URBS * 4,
814                                          GFP_KERNEL, &ep->sync_dma);
815         if (!ep->syncbuf)
816                 return -ENOMEM;
817 
818         for (i = 0; i < SYNC_URBS; i++) {
819                 struct snd_urb_ctx *u = &ep->urb[i];
820                 u->index = i;
821                 u->ep = ep;
822                 u->packets = 1;
823                 u->urb = usb_alloc_urb(1, GFP_KERNEL);
824                 if (!u->urb)
825                         goto out_of_memory;
826                 u->urb->transfer_buffer = ep->syncbuf + i * 4;
827                 u->urb->transfer_dma = ep->sync_dma + i * 4;
828                 u->urb->transfer_buffer_length = 4;
829                 u->urb->pipe = ep->pipe;
830                 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
831                 u->urb->number_of_packets = 1;
832                 u->urb->interval = 1 << ep->syncinterval;
833                 u->urb->context = u;
834                 u->urb->complete = snd_complete_urb;
835         }
836 
837         ep->nurbs = SYNC_URBS;
838 
839         return 0;
840 
841 out_of_memory:
842         release_urbs(ep, 0);
843         return -ENOMEM;
844 }
845 
846 /**
847  * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
848  *
849  * @ep: the snd_usb_endpoint to configure
850  * @pcm_format: the audio fomat.
851  * @channels: the number of audio channels.
852  * @period_bytes: the number of bytes in one alsa period.
853  * @period_frames: the number of frames in one alsa period.
854  * @buffer_periods: the number of periods in one alsa buffer.
855  * @rate: the frame rate.
856  * @fmt: the USB audio format information
857  * @sync_ep: the sync endpoint to use, if any
858  *
859  * Determine the number of URBs to be used on this endpoint.
860  * An endpoint must be configured before it can be started.
861  * An endpoint that is already running can not be reconfigured.
862  */
863 int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
864                                 snd_pcm_format_t pcm_format,
865                                 unsigned int channels,
866                                 unsigned int period_bytes,
867                                 unsigned int period_frames,
868                                 unsigned int buffer_periods,
869                                 unsigned int rate,
870                                 struct audioformat *fmt,
871                                 struct snd_usb_endpoint *sync_ep)
872 {
873         int err;
874 
875         if (ep->use_count != 0) {
876                 usb_audio_warn(ep->chip,
877                          "Unable to change format on ep #%x: already in use\n",
878                          ep->ep_num);
879                 return -EBUSY;
880         }
881 
882         /* release old buffers, if any */
883         release_urbs(ep, 0);
884 
885         ep->datainterval = fmt->datainterval;
886         ep->maxpacksize = fmt->maxpacksize;
887         ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
888 
889         if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL)
890                 ep->freqn = get_usb_full_speed_rate(rate);
891         else
892                 ep->freqn = get_usb_high_speed_rate(rate);
893 
894         /* calculate the frequency in 16.16 format */
895         ep->freqm = ep->freqn;
896         ep->freqshift = INT_MIN;
897 
898         ep->phase = 0;
899 
900         switch (ep->type) {
901         case  SND_USB_ENDPOINT_TYPE_DATA:
902                 err = data_ep_set_params(ep, pcm_format, channels,
903                                          period_bytes, period_frames,
904                                          buffer_periods, fmt, sync_ep);
905                 break;
906         case  SND_USB_ENDPOINT_TYPE_SYNC:
907                 err = sync_ep_set_params(ep);
908                 break;
909         default:
910                 err = -EINVAL;
911         }
912 
913         usb_audio_dbg(ep->chip,
914                 "Setting params for ep #%x (type %d, %d urbs), ret=%d\n",
915                 ep->ep_num, ep->type, ep->nurbs, err);
916 
917         return err;
918 }
919 
920 /**
921  * snd_usb_endpoint_start: start an snd_usb_endpoint
922  *
923  * @ep: the endpoint to start
924  *
925  * A call to this function will increment the use count of the endpoint.
926  * In case it is not already running, the URBs for this endpoint will be
927  * submitted. Otherwise, this function does nothing.
928  *
929  * Must be balanced to calls of snd_usb_endpoint_stop().
930  *
931  * Returns an error if the URB submission failed, 0 in all other cases.
932  */
933 int snd_usb_endpoint_start(struct snd_usb_endpoint *ep)
934 {
935         int err;
936         unsigned int i;
937 
938         if (atomic_read(&ep->chip->shutdown))
939                 return -EBADFD;
940 
941         /* already running? */
942         if (++ep->use_count != 1)
943                 return 0;
944 
945         /* just to be sure */
946         deactivate_urbs(ep, false);
947 
948         ep->active_mask = 0;
949         ep->unlink_mask = 0;
950         ep->phase = 0;
951 
952         snd_usb_endpoint_start_quirk(ep);
953 
954         /*
955          * If this endpoint has a data endpoint as implicit feedback source,
956          * don't start the urbs here. Instead, mark them all as available,
957          * wait for the record urbs to return and queue the playback urbs
958          * from that context.
959          */
960 
961         set_bit(EP_FLAG_RUNNING, &ep->flags);
962 
963         if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
964                 for (i = 0; i < ep->nurbs; i++) {
965                         struct snd_urb_ctx *ctx = ep->urb + i;
966                         list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
967                 }
968 
969                 return 0;
970         }
971 
972         for (i = 0; i < ep->nurbs; i++) {
973                 struct urb *urb = ep->urb[i].urb;
974 
975                 if (snd_BUG_ON(!urb))
976                         goto __error;
977 
978                 if (usb_pipeout(ep->pipe)) {
979                         prepare_outbound_urb(ep, urb->context);
980                 } else {
981                         prepare_inbound_urb(ep, urb->context);
982                 }
983 
984                 err = usb_submit_urb(urb, GFP_ATOMIC);
985                 if (err < 0) {
986                         usb_audio_err(ep->chip,
987                                 "cannot submit urb %d, error %d: %s\n",
988                                 i, err, usb_error_string(err));
989                         goto __error;
990                 }
991                 set_bit(i, &ep->active_mask);
992         }
993 
994         return 0;
995 
996 __error:
997         clear_bit(EP_FLAG_RUNNING, &ep->flags);
998         ep->use_count--;
999         deactivate_urbs(ep, false);
1000         return -EPIPE;
1001 }
1002 
1003 /**
1004  * snd_usb_endpoint_stop: stop an snd_usb_endpoint
1005  *
1006  * @ep: the endpoint to stop (may be NULL)
1007  *
1008  * A call to this function will decrement the use count of the endpoint.
1009  * In case the last user has requested the endpoint stop, the URBs will
1010  * actually be deactivated.
1011  *
1012  * Must be balanced to calls of snd_usb_endpoint_start().
1013  *
1014  * The caller needs to synchronize the pending stop operation via
1015  * snd_usb_endpoint_sync_pending_stop().
1016  */
1017 void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep)
1018 {
1019         if (!ep)
1020                 return;
1021 
1022         if (snd_BUG_ON(ep->use_count == 0))
1023                 return;
1024 
1025         if (--ep->use_count == 0) {
1026                 deactivate_urbs(ep, false);
1027                 set_bit(EP_FLAG_STOPPING, &ep->flags);
1028         }
1029 }
1030 
1031 /**
1032  * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint
1033  *
1034  * @ep: the endpoint to deactivate
1035  *
1036  * If the endpoint is not currently in use, this functions will
1037  * deactivate its associated URBs.
1038  *
1039  * In case of any active users, this functions does nothing.
1040  */
1041 void snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep)
1042 {
1043         if (!ep)
1044                 return;
1045 
1046         if (ep->use_count != 0)
1047                 return;
1048 
1049         deactivate_urbs(ep, true);
1050         wait_clear_urbs(ep);
1051 }
1052 
1053 /**
1054  * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
1055  *
1056  * @ep: the endpoint to release
1057  *
1058  * This function does not care for the endpoint's use count but will tear
1059  * down all the streaming URBs immediately.
1060  */
1061 void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
1062 {
1063         release_urbs(ep, 1);
1064 }
1065 
1066 /**
1067  * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint
1068  *
1069  * @ep: the endpoint to free
1070  *
1071  * This free all resources of the given ep.
1072  */
1073 void snd_usb_endpoint_free(struct snd_usb_endpoint *ep)
1074 {
1075         kfree(ep);
1076 }
1077 
1078 /**
1079  * snd_usb_handle_sync_urb: parse an USB sync packet
1080  *
1081  * @ep: the endpoint to handle the packet
1082  * @sender: the sending endpoint
1083  * @urb: the received packet
1084  *
1085  * This function is called from the context of an endpoint that received
1086  * the packet and is used to let another endpoint object handle the payload.
1087  */
1088 void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
1089                              struct snd_usb_endpoint *sender,
1090                              const struct urb *urb)
1091 {
1092         int shift;
1093         unsigned int f;
1094         unsigned long flags;
1095 
1096         snd_BUG_ON(ep == sender);
1097 
1098         /*
1099          * In case the endpoint is operating in implicit feedback mode, prepare
1100          * a new outbound URB that has the same layout as the received packet
1101          * and add it to the list of pending urbs. queue_pending_output_urbs()
1102          * will take care of them later.
1103          */
1104         if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1105             ep->use_count != 0) {
1106 
1107                 /* implicit feedback case */
1108                 int i, bytes = 0;
1109                 struct snd_urb_ctx *in_ctx;
1110                 struct snd_usb_packet_info *out_packet;
1111 
1112                 in_ctx = urb->context;
1113 
1114                 /* Count overall packet size */
1115                 for (i = 0; i < in_ctx->packets; i++)
1116                         if (urb->iso_frame_desc[i].status == 0)
1117                                 bytes += urb->iso_frame_desc[i].actual_length;
1118 
1119                 /*
1120                  * skip empty packets. At least M-Audio's Fast Track Ultra stops
1121                  * streaming once it received a 0-byte OUT URB
1122                  */
1123                 if (bytes == 0)
1124                         return;
1125 
1126                 spin_lock_irqsave(&ep->lock, flags);
1127                 out_packet = ep->next_packet + ep->next_packet_write_pos;
1128 
1129                 /*
1130                  * Iterate through the inbound packet and prepare the lengths
1131                  * for the output packet. The OUT packet we are about to send
1132                  * will have the same amount of payload bytes per stride as the
1133                  * IN packet we just received. Since the actual size is scaled
1134                  * by the stride, use the sender stride to calculate the length
1135                  * in case the number of channels differ between the implicitly
1136                  * fed-back endpoint and the synchronizing endpoint.
1137                  */
1138 
1139                 out_packet->packets = in_ctx->packets;
1140                 for (i = 0; i < in_ctx->packets; i++) {
1141                         if (urb->iso_frame_desc[i].status == 0)
1142                                 out_packet->packet_size[i] =
1143                                         urb->iso_frame_desc[i].actual_length / sender->stride;
1144                         else
1145                                 out_packet->packet_size[i] = 0;
1146                 }
1147 
1148                 ep->next_packet_write_pos++;
1149                 ep->next_packet_write_pos %= MAX_URBS;
1150                 spin_unlock_irqrestore(&ep->lock, flags);
1151                 queue_pending_output_urbs(ep);
1152 
1153                 return;
1154         }
1155 
1156         /*
1157          * process after playback sync complete
1158          *
1159          * Full speed devices report feedback values in 10.14 format as samples
1160          * per frame, high speed devices in 16.16 format as samples per
1161          * microframe.
1162          *
1163          * Because the Audio Class 1 spec was written before USB 2.0, many high
1164          * speed devices use a wrong interpretation, some others use an
1165          * entirely different format.
1166          *
1167          * Therefore, we cannot predict what format any particular device uses
1168          * and must detect it automatically.
1169          */
1170 
1171         if (urb->iso_frame_desc[0].status != 0 ||
1172             urb->iso_frame_desc[0].actual_length < 3)
1173                 return;
1174 
1175         f = le32_to_cpup(urb->transfer_buffer);
1176         if (urb->iso_frame_desc[0].actual_length == 3)
1177                 f &= 0x00ffffff;
1178         else
1179                 f &= 0x0fffffff;
1180 
1181         if (f == 0)
1182                 return;
1183 
1184         if (unlikely(sender->tenor_fb_quirk)) {
1185                 /*
1186                  * Devices based on Tenor 8802 chipsets (TEAC UD-H01
1187                  * and others) sometimes change the feedback value
1188                  * by +/- 0x1.0000.
1189                  */
1190                 if (f < ep->freqn - 0x8000)
1191                         f += 0xf000;
1192                 else if (f > ep->freqn + 0x8000)
1193                         f -= 0xf000;
1194         } else if (unlikely(ep->freqshift == INT_MIN)) {
1195                 /*
1196                  * The first time we see a feedback value, determine its format
1197                  * by shifting it left or right until it matches the nominal
1198                  * frequency value.  This assumes that the feedback does not
1199                  * differ from the nominal value more than +50% or -25%.
1200                  */
1201                 shift = 0;
1202                 while (f < ep->freqn - ep->freqn / 4) {
1203                         f <<= 1;
1204                         shift++;
1205                 }
1206                 while (f > ep->freqn + ep->freqn / 2) {
1207                         f >>= 1;
1208                         shift--;
1209                 }
1210                 ep->freqshift = shift;
1211         } else if (ep->freqshift >= 0)
1212                 f <<= ep->freqshift;
1213         else
1214                 f >>= -ep->freqshift;
1215 
1216         if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {
1217                 /*
1218                  * If the frequency looks valid, set it.
1219                  * This value is referred to in prepare_playback_urb().
1220                  */
1221                 spin_lock_irqsave(&ep->lock, flags);
1222                 ep->freqm = f;
1223                 spin_unlock_irqrestore(&ep->lock, flags);
1224         } else {
1225                 /*
1226                  * Out of range; maybe the shift value is wrong.
1227                  * Reset it so that we autodetect again the next time.
1228                  */
1229                 ep->freqshift = INT_MIN;
1230         }
1231 }
1232 
1233 

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