~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

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

Version: ~ [ linux-5.11 ] ~ [ linux-5.10.17 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.99 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.176 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.221 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.257 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.257 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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                 int err, i;
329 
330                 spin_lock_irqsave(&ep->lock, flags);
331                 if (ep->next_packet_read_pos != ep->next_packet_write_pos) {
332                         packet = ep->next_packet + ep->next_packet_read_pos;
333                         ep->next_packet_read_pos++;
334                         ep->next_packet_read_pos %= MAX_URBS;
335 
336                         /* take URB out of FIFO */
337                         if (!list_empty(&ep->ready_playback_urbs))
338                                 ctx = list_first_entry(&ep->ready_playback_urbs,
339                                                struct snd_urb_ctx, ready_list);
340                 }
341                 spin_unlock_irqrestore(&ep->lock, flags);
342 
343                 if (ctx == NULL)
344                         return;
345 
346                 list_del_init(&ctx->ready_list);
347 
348                 /* copy over the length information */
349                 for (i = 0; i < packet->packets; i++)
350                         ctx->packet_size[i] = packet->packet_size[i];
351 
352                 /* call the data handler to fill in playback data */
353                 prepare_outbound_urb(ep, ctx);
354 
355                 err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
356                 if (err < 0)
357                         usb_audio_err(ep->chip,
358                                 "Unable to submit urb #%d: %d (urb %p)\n",
359                                 ctx->index, err, ctx->urb);
360                 else
361                         set_bit(ctx->index, &ep->active_mask);
362         }
363 }
364 
365 /*
366  * complete callback for urbs
367  */
368 static void snd_complete_urb(struct urb *urb)
369 {
370         struct snd_urb_ctx *ctx = urb->context;
371         struct snd_usb_endpoint *ep = ctx->ep;
372         struct snd_pcm_substream *substream;
373         unsigned long flags;
374         int err;
375 
376         if (unlikely(urb->status == -ENOENT ||          /* unlinked */
377                      urb->status == -ENODEV ||          /* device removed */
378                      urb->status == -ECONNRESET ||      /* unlinked */
379                      urb->status == -ESHUTDOWN))        /* device disabled */
380                 goto exit_clear;
381         /* device disconnected */
382         if (unlikely(atomic_read(&ep->chip->shutdown)))
383                 goto exit_clear;
384 
385         if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
386                 goto exit_clear;
387 
388         if (usb_pipeout(ep->pipe)) {
389                 retire_outbound_urb(ep, ctx);
390                 /* can be stopped during retire callback */
391                 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
392                         goto exit_clear;
393 
394                 if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
395                         spin_lock_irqsave(&ep->lock, flags);
396                         list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
397                         spin_unlock_irqrestore(&ep->lock, flags);
398                         queue_pending_output_urbs(ep);
399 
400                         goto exit_clear;
401                 }
402 
403                 prepare_outbound_urb(ep, ctx);
404         } else {
405                 retire_inbound_urb(ep, ctx);
406                 /* can be stopped during retire callback */
407                 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
408                         goto exit_clear;
409 
410                 prepare_inbound_urb(ep, ctx);
411         }
412 
413         err = usb_submit_urb(urb, GFP_ATOMIC);
414         if (err == 0)
415                 return;
416 
417         usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
418         if (ep->data_subs && ep->data_subs->pcm_substream) {
419                 substream = ep->data_subs->pcm_substream;
420                 snd_pcm_stop_xrun(substream);
421         }
422 
423 exit_clear:
424         clear_bit(ctx->index, &ep->active_mask);
425 }
426 
427 /**
428  * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
429  *
430  * @chip: The chip
431  * @alts: The USB host interface
432  * @ep_num: The number of the endpoint to use
433  * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE
434  * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
435  *
436  * If the requested endpoint has not been added to the given chip before,
437  * a new instance is created. Otherwise, a pointer to the previoulsy
438  * created instance is returned. In case of any error, NULL is returned.
439  *
440  * New endpoints will be added to chip->ep_list and must be freed by
441  * calling snd_usb_endpoint_free().
442  *
443  * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
444  * bNumEndpoints > 1 beforehand.
445  */
446 struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip,
447                                               struct usb_host_interface *alts,
448                                               int ep_num, int direction, int type)
449 {
450         struct snd_usb_endpoint *ep;
451         int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK;
452 
453         if (WARN_ON(!alts))
454                 return NULL;
455 
456         mutex_lock(&chip->mutex);
457 
458         list_for_each_entry(ep, &chip->ep_list, list) {
459                 if (ep->ep_num == ep_num &&
460                     ep->iface == alts->desc.bInterfaceNumber &&
461                     ep->altsetting == alts->desc.bAlternateSetting) {
462                         usb_audio_dbg(ep->chip,
463                                       "Re-using EP %x in iface %d,%d @%p\n",
464                                         ep_num, ep->iface, ep->altsetting, ep);
465                         goto __exit_unlock;
466                 }
467         }
468 
469         usb_audio_dbg(chip, "Creating new %s %s endpoint #%x\n",
470                     is_playback ? "playback" : "capture",
471                     type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync",
472                     ep_num);
473 
474         ep = kzalloc(sizeof(*ep), GFP_KERNEL);
475         if (!ep)
476                 goto __exit_unlock;
477 
478         ep->chip = chip;
479         spin_lock_init(&ep->lock);
480         ep->type = type;
481         ep->ep_num = ep_num;
482         ep->iface = alts->desc.bInterfaceNumber;
483         ep->altsetting = alts->desc.bAlternateSetting;
484         INIT_LIST_HEAD(&ep->ready_playback_urbs);
485         ep_num &= USB_ENDPOINT_NUMBER_MASK;
486 
487         if (is_playback)
488                 ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
489         else
490                 ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);
491 
492         if (type == SND_USB_ENDPOINT_TYPE_SYNC) {
493                 if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
494                     get_endpoint(alts, 1)->bRefresh >= 1 &&
495                     get_endpoint(alts, 1)->bRefresh <= 9)
496                         ep->syncinterval = get_endpoint(alts, 1)->bRefresh;
497                 else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
498                         ep->syncinterval = 1;
499                 else if (get_endpoint(alts, 1)->bInterval >= 1 &&
500                          get_endpoint(alts, 1)->bInterval <= 16)
501                         ep->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
502                 else
503                         ep->syncinterval = 3;
504 
505                 ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize);
506         }
507 
508         list_add_tail(&ep->list, &chip->ep_list);
509 
510 __exit_unlock:
511         mutex_unlock(&chip->mutex);
512 
513         return ep;
514 }
515 
516 /*
517  *  wait until all urbs are processed.
518  */
519 static int wait_clear_urbs(struct snd_usb_endpoint *ep)
520 {
521         unsigned long end_time = jiffies + msecs_to_jiffies(1000);
522         int alive;
523 
524         do {
525                 alive = bitmap_weight(&ep->active_mask, ep->nurbs);
526                 if (!alive)
527                         break;
528 
529                 schedule_timeout_uninterruptible(1);
530         } while (time_before(jiffies, end_time));
531 
532         if (alive)
533                 usb_audio_err(ep->chip,
534                         "timeout: still %d active urbs on EP #%x\n",
535                         alive, ep->ep_num);
536         clear_bit(EP_FLAG_STOPPING, &ep->flags);
537 
538         ep->data_subs = NULL;
539         ep->sync_slave = NULL;
540         ep->retire_data_urb = NULL;
541         ep->prepare_data_urb = NULL;
542 
543         return 0;
544 }
545 
546 /* sync the pending stop operation;
547  * this function itself doesn't trigger the stop operation
548  */
549 void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
550 {
551         if (ep && test_bit(EP_FLAG_STOPPING, &ep->flags))
552                 wait_clear_urbs(ep);
553 }
554 
555 /*
556  * unlink active urbs.
557  */
558 static int deactivate_urbs(struct snd_usb_endpoint *ep, bool force)
559 {
560         unsigned int i;
561 
562         if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */
563                 return -EBADFD;
564 
565         clear_bit(EP_FLAG_RUNNING, &ep->flags);
566 
567         INIT_LIST_HEAD(&ep->ready_playback_urbs);
568         ep->next_packet_read_pos = 0;
569         ep->next_packet_write_pos = 0;
570 
571         for (i = 0; i < ep->nurbs; i++) {
572                 if (test_bit(i, &ep->active_mask)) {
573                         if (!test_and_set_bit(i, &ep->unlink_mask)) {
574                                 struct urb *u = ep->urb[i].urb;
575                                 usb_unlink_urb(u);
576                         }
577                 }
578         }
579 
580         return 0;
581 }
582 
583 /*
584  * release an endpoint's urbs
585  */
586 static void release_urbs(struct snd_usb_endpoint *ep, int force)
587 {
588         int i;
589 
590         /* route incoming urbs to nirvana */
591         ep->retire_data_urb = NULL;
592         ep->prepare_data_urb = NULL;
593 
594         /* stop urbs */
595         deactivate_urbs(ep, force);
596         wait_clear_urbs(ep);
597 
598         for (i = 0; i < ep->nurbs; i++)
599                 release_urb_ctx(&ep->urb[i]);
600 
601         if (ep->syncbuf)
602                 usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
603                                   ep->syncbuf, ep->sync_dma);
604 
605         ep->syncbuf = NULL;
606         ep->nurbs = 0;
607 }
608 
609 /*
610  * configure a data endpoint
611  */
612 static int data_ep_set_params(struct snd_usb_endpoint *ep,
613                               snd_pcm_format_t pcm_format,
614                               unsigned int channels,
615                               unsigned int period_bytes,
616                               unsigned int frames_per_period,
617                               unsigned int periods_per_buffer,
618                               struct audioformat *fmt,
619                               struct snd_usb_endpoint *sync_ep)
620 {
621         unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
622         unsigned int max_packs_per_period, urbs_per_period, urb_packs;
623         unsigned int max_urbs, i;
624         int frame_bits = snd_pcm_format_physical_width(pcm_format) * channels;
625         int tx_length_quirk = (ep->chip->tx_length_quirk &&
626                                usb_pipeout(ep->pipe));
627 
628         if (pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
629                 /*
630                  * When operating in DSD DOP mode, the size of a sample frame
631                  * in hardware differs from the actual physical format width
632                  * because we need to make room for the DOP markers.
633                  */
634                 frame_bits += channels << 3;
635         }
636 
637         ep->datainterval = fmt->datainterval;
638         ep->stride = frame_bits >> 3;
639 
640         switch (pcm_format) {
641         case SNDRV_PCM_FORMAT_U8:
642                 ep->silence_value = 0x80;
643                 break;
644         case SNDRV_PCM_FORMAT_DSD_U8:
645         case SNDRV_PCM_FORMAT_DSD_U16_LE:
646         case SNDRV_PCM_FORMAT_DSD_U32_LE:
647         case SNDRV_PCM_FORMAT_DSD_U16_BE:
648         case SNDRV_PCM_FORMAT_DSD_U32_BE:
649                 ep->silence_value = 0x69;
650                 break;
651         default:
652                 ep->silence_value = 0;
653         }
654 
655         /* assume max. frequency is 50% higher than nominal */
656         ep->freqmax = ep->freqn + (ep->freqn >> 1);
657         /* Round up freqmax to nearest integer in order to calculate maximum
658          * packet size, which must represent a whole number of frames.
659          * This is accomplished by adding 0x0.ffff before converting the
660          * Q16.16 format into integer.
661          * In order to accurately calculate the maximum packet size when
662          * the data interval is more than 1 (i.e. ep->datainterval > 0),
663          * multiply by the data interval prior to rounding. For instance,
664          * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
665          * frames with a data interval of 1, but 11 (10.25) frames with a
666          * data interval of 2.
667          * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
668          * maximum datainterval value of 3, at USB full speed, higher for
669          * USB high speed, noting that ep->freqmax is in units of
670          * frames per packet in Q16.16 format.)
671          */
672         maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
673                          (frame_bits >> 3);
674         if (tx_length_quirk)
675                 maxsize += sizeof(__le32); /* Space for length descriptor */
676         /* but wMaxPacketSize might reduce this */
677         if (ep->maxpacksize && ep->maxpacksize < maxsize) {
678                 /* whatever fits into a max. size packet */
679                 unsigned int data_maxsize = maxsize = ep->maxpacksize;
680 
681                 if (tx_length_quirk)
682                         /* Need to remove the length descriptor to calc freq */
683                         data_maxsize -= sizeof(__le32);
684                 ep->freqmax = (data_maxsize / (frame_bits >> 3))
685                                 << (16 - ep->datainterval);
686         }
687 
688         if (ep->fill_max)
689                 ep->curpacksize = ep->maxpacksize;
690         else
691                 ep->curpacksize = maxsize;
692 
693         if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) {
694                 packs_per_ms = 8 >> ep->datainterval;
695                 max_packs_per_urb = MAX_PACKS_HS;
696         } else {
697                 packs_per_ms = 1;
698                 max_packs_per_urb = MAX_PACKS;
699         }
700         if (sync_ep && !snd_usb_endpoint_implicit_feedback_sink(ep))
701                 max_packs_per_urb = min(max_packs_per_urb,
702                                         1U << sync_ep->syncinterval);
703         max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);
704 
705         /*
706          * Capture endpoints need to use small URBs because there's no way
707          * to tell in advance where the next period will end, and we don't
708          * want the next URB to complete much after the period ends.
709          *
710          * Playback endpoints with implicit sync much use the same parameters
711          * as their corresponding capture endpoint.
712          */
713         if (usb_pipein(ep->pipe) ||
714                         snd_usb_endpoint_implicit_feedback_sink(ep)) {
715 
716                 urb_packs = packs_per_ms;
717                 /*
718                  * Wireless devices can poll at a max rate of once per 4ms.
719                  * For dataintervals less than 5, increase the packet count to
720                  * allow the host controller to use bursting to fill in the
721                  * gaps.
722                  */
723                 if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_WIRELESS) {
724                         int interval = ep->datainterval;
725                         while (interval < 5) {
726                                 urb_packs <<= 1;
727                                 ++interval;
728                         }
729                 }
730                 /* make capture URBs <= 1 ms and smaller than a period */
731                 urb_packs = min(max_packs_per_urb, urb_packs);
732                 while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
733                         urb_packs >>= 1;
734                 ep->nurbs = MAX_URBS;
735 
736         /*
737          * Playback endpoints without implicit sync are adjusted so that
738          * a period fits as evenly as possible in the smallest number of
739          * URBs.  The total number of URBs is adjusted to the size of the
740          * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
741          */
742         } else {
743                 /* determine how small a packet can be */
744                 minsize = (ep->freqn >> (16 - ep->datainterval)) *
745                                 (frame_bits >> 3);
746                 /* with sync from device, assume it can be 12% lower */
747                 if (sync_ep)
748                         minsize -= minsize >> 3;
749                 minsize = max(minsize, 1u);
750 
751                 /* how many packets will contain an entire ALSA period? */
752                 max_packs_per_period = DIV_ROUND_UP(period_bytes, minsize);
753 
754                 /* how many URBs will contain a period? */
755                 urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
756                                 max_packs_per_urb);
757                 /* how many packets are needed in each URB? */
758                 urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);
759 
760                 /* limit the number of frames in a single URB */
761                 ep->max_urb_frames = DIV_ROUND_UP(frames_per_period,
762                                         urbs_per_period);
763 
764                 /* try to use enough URBs to contain an entire ALSA buffer */
765                 max_urbs = min((unsigned) MAX_URBS,
766                                 MAX_QUEUE * packs_per_ms / urb_packs);
767                 ep->nurbs = min(max_urbs, urbs_per_period * periods_per_buffer);
768         }
769 
770         /* allocate and initialize data urbs */
771         for (i = 0; i < ep->nurbs; i++) {
772                 struct snd_urb_ctx *u = &ep->urb[i];
773                 u->index = i;
774                 u->ep = ep;
775                 u->packets = urb_packs;
776                 u->buffer_size = maxsize * u->packets;
777 
778                 if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
779                         u->packets++; /* for transfer delimiter */
780                 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
781                 if (!u->urb)
782                         goto out_of_memory;
783 
784                 u->urb->transfer_buffer =
785                         usb_alloc_coherent(ep->chip->dev, u->buffer_size,
786                                            GFP_KERNEL, &u->urb->transfer_dma);
787                 if (!u->urb->transfer_buffer)
788                         goto out_of_memory;
789                 u->urb->pipe = ep->pipe;
790                 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
791                 u->urb->interval = 1 << ep->datainterval;
792                 u->urb->context = u;
793                 u->urb->complete = snd_complete_urb;
794                 INIT_LIST_HEAD(&u->ready_list);
795         }
796 
797         return 0;
798 
799 out_of_memory:
800         release_urbs(ep, 0);
801         return -ENOMEM;
802 }
803 
804 /*
805  * configure a sync endpoint
806  */
807 static int sync_ep_set_params(struct snd_usb_endpoint *ep)
808 {
809         int i;
810 
811         ep->syncbuf = usb_alloc_coherent(ep->chip->dev, SYNC_URBS * 4,
812                                          GFP_KERNEL, &ep->sync_dma);
813         if (!ep->syncbuf)
814                 return -ENOMEM;
815 
816         for (i = 0; i < SYNC_URBS; i++) {
817                 struct snd_urb_ctx *u = &ep->urb[i];
818                 u->index = i;
819                 u->ep = ep;
820                 u->packets = 1;
821                 u->urb = usb_alloc_urb(1, GFP_KERNEL);
822                 if (!u->urb)
823                         goto out_of_memory;
824                 u->urb->transfer_buffer = ep->syncbuf + i * 4;
825                 u->urb->transfer_dma = ep->sync_dma + i * 4;
826                 u->urb->transfer_buffer_length = 4;
827                 u->urb->pipe = ep->pipe;
828                 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
829                 u->urb->number_of_packets = 1;
830                 u->urb->interval = 1 << ep->syncinterval;
831                 u->urb->context = u;
832                 u->urb->complete = snd_complete_urb;
833         }
834 
835         ep->nurbs = SYNC_URBS;
836 
837         return 0;
838 
839 out_of_memory:
840         release_urbs(ep, 0);
841         return -ENOMEM;
842 }
843 
844 /**
845  * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
846  *
847  * @ep: the snd_usb_endpoint to configure
848  * @pcm_format: the audio fomat.
849  * @channels: the number of audio channels.
850  * @period_bytes: the number of bytes in one alsa period.
851  * @period_frames: the number of frames in one alsa period.
852  * @buffer_periods: the number of periods in one alsa buffer.
853  * @rate: the frame rate.
854  * @fmt: the USB audio format information
855  * @sync_ep: the sync endpoint to use, if any
856  *
857  * Determine the number of URBs to be used on this endpoint.
858  * An endpoint must be configured before it can be started.
859  * An endpoint that is already running can not be reconfigured.
860  */
861 int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
862                                 snd_pcm_format_t pcm_format,
863                                 unsigned int channels,
864                                 unsigned int period_bytes,
865                                 unsigned int period_frames,
866                                 unsigned int buffer_periods,
867                                 unsigned int rate,
868                                 struct audioformat *fmt,
869                                 struct snd_usb_endpoint *sync_ep)
870 {
871         int err;
872 
873         if (ep->use_count != 0) {
874                 usb_audio_warn(ep->chip,
875                          "Unable to change format on ep #%x: already in use\n",
876                          ep->ep_num);
877                 return -EBUSY;
878         }
879 
880         /* release old buffers, if any */
881         release_urbs(ep, 0);
882 
883         ep->datainterval = fmt->datainterval;
884         ep->maxpacksize = fmt->maxpacksize;
885         ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
886 
887         if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL)
888                 ep->freqn = get_usb_full_speed_rate(rate);
889         else
890                 ep->freqn = get_usb_high_speed_rate(rate);
891 
892         /* calculate the frequency in 16.16 format */
893         ep->freqm = ep->freqn;
894         ep->freqshift = INT_MIN;
895 
896         ep->phase = 0;
897 
898         switch (ep->type) {
899         case  SND_USB_ENDPOINT_TYPE_DATA:
900                 err = data_ep_set_params(ep, pcm_format, channels,
901                                          period_bytes, period_frames,
902                                          buffer_periods, fmt, sync_ep);
903                 break;
904         case  SND_USB_ENDPOINT_TYPE_SYNC:
905                 err = sync_ep_set_params(ep);
906                 break;
907         default:
908                 err = -EINVAL;
909         }
910 
911         usb_audio_dbg(ep->chip,
912                 "Setting params for ep #%x (type %d, %d urbs), ret=%d\n",
913                 ep->ep_num, ep->type, ep->nurbs, err);
914 
915         return err;
916 }
917 
918 /**
919  * snd_usb_endpoint_start: start an snd_usb_endpoint
920  *
921  * @ep: the endpoint to start
922  *
923  * A call to this function will increment the use count of the endpoint.
924  * In case it is not already running, the URBs for this endpoint will be
925  * submitted. Otherwise, this function does nothing.
926  *
927  * Must be balanced to calls of snd_usb_endpoint_stop().
928  *
929  * Returns an error if the URB submission failed, 0 in all other cases.
930  */
931 int snd_usb_endpoint_start(struct snd_usb_endpoint *ep)
932 {
933         int err;
934         unsigned int i;
935 
936         if (atomic_read(&ep->chip->shutdown))
937                 return -EBADFD;
938 
939         /* already running? */
940         if (++ep->use_count != 1)
941                 return 0;
942 
943         /* just to be sure */
944         deactivate_urbs(ep, false);
945 
946         ep->active_mask = 0;
947         ep->unlink_mask = 0;
948         ep->phase = 0;
949 
950         snd_usb_endpoint_start_quirk(ep);
951 
952         /*
953          * If this endpoint has a data endpoint as implicit feedback source,
954          * don't start the urbs here. Instead, mark them all as available,
955          * wait for the record urbs to return and queue the playback urbs
956          * from that context.
957          */
958 
959         set_bit(EP_FLAG_RUNNING, &ep->flags);
960 
961         if (snd_usb_endpoint_implicit_feedback_sink(ep)) {
962                 for (i = 0; i < ep->nurbs; i++) {
963                         struct snd_urb_ctx *ctx = ep->urb + i;
964                         list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
965                 }
966 
967                 return 0;
968         }
969 
970         for (i = 0; i < ep->nurbs; i++) {
971                 struct urb *urb = ep->urb[i].urb;
972 
973                 if (snd_BUG_ON(!urb))
974                         goto __error;
975 
976                 if (usb_pipeout(ep->pipe)) {
977                         prepare_outbound_urb(ep, urb->context);
978                 } else {
979                         prepare_inbound_urb(ep, urb->context);
980                 }
981 
982                 err = usb_submit_urb(urb, GFP_ATOMIC);
983                 if (err < 0) {
984                         usb_audio_err(ep->chip,
985                                 "cannot submit urb %d, error %d: %s\n",
986                                 i, err, usb_error_string(err));
987                         goto __error;
988                 }
989                 set_bit(i, &ep->active_mask);
990         }
991 
992         return 0;
993 
994 __error:
995         clear_bit(EP_FLAG_RUNNING, &ep->flags);
996         ep->use_count--;
997         deactivate_urbs(ep, false);
998         return -EPIPE;
999 }
1000 
1001 /**
1002  * snd_usb_endpoint_stop: stop an snd_usb_endpoint
1003  *
1004  * @ep: the endpoint to stop (may be NULL)
1005  *
1006  * A call to this function will decrement the use count of the endpoint.
1007  * In case the last user has requested the endpoint stop, the URBs will
1008  * actually be deactivated.
1009  *
1010  * Must be balanced to calls of snd_usb_endpoint_start().
1011  *
1012  * The caller needs to synchronize the pending stop operation via
1013  * snd_usb_endpoint_sync_pending_stop().
1014  */
1015 void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep)
1016 {
1017         if (!ep)
1018                 return;
1019 
1020         if (snd_BUG_ON(ep->use_count == 0))
1021                 return;
1022 
1023         if (--ep->use_count == 0) {
1024                 deactivate_urbs(ep, false);
1025                 set_bit(EP_FLAG_STOPPING, &ep->flags);
1026         }
1027 }
1028 
1029 /**
1030  * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint
1031  *
1032  * @ep: the endpoint to deactivate
1033  *
1034  * If the endpoint is not currently in use, this functions will
1035  * deactivate its associated URBs.
1036  *
1037  * In case of any active users, this functions does nothing.
1038  */
1039 void snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep)
1040 {
1041         if (!ep)
1042                 return;
1043 
1044         if (ep->use_count != 0)
1045                 return;
1046 
1047         deactivate_urbs(ep, true);
1048         wait_clear_urbs(ep);
1049 }
1050 
1051 /**
1052  * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
1053  *
1054  * @ep: the endpoint to release
1055  *
1056  * This function does not care for the endpoint's use count but will tear
1057  * down all the streaming URBs immediately.
1058  */
1059 void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
1060 {
1061         release_urbs(ep, 1);
1062 }
1063 
1064 /**
1065  * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint
1066  *
1067  * @ep: the endpoint to free
1068  *
1069  * This free all resources of the given ep.
1070  */
1071 void snd_usb_endpoint_free(struct snd_usb_endpoint *ep)
1072 {
1073         kfree(ep);
1074 }
1075 
1076 /**
1077  * snd_usb_handle_sync_urb: parse an USB sync packet
1078  *
1079  * @ep: the endpoint to handle the packet
1080  * @sender: the sending endpoint
1081  * @urb: the received packet
1082  *
1083  * This function is called from the context of an endpoint that received
1084  * the packet and is used to let another endpoint object handle the payload.
1085  */
1086 void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
1087                              struct snd_usb_endpoint *sender,
1088                              const struct urb *urb)
1089 {
1090         int shift;
1091         unsigned int f;
1092         unsigned long flags;
1093 
1094         snd_BUG_ON(ep == sender);
1095 
1096         /*
1097          * In case the endpoint is operating in implicit feedback mode, prepare
1098          * a new outbound URB that has the same layout as the received packet
1099          * and add it to the list of pending urbs. queue_pending_output_urbs()
1100          * will take care of them later.
1101          */
1102         if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1103             ep->use_count != 0) {
1104 
1105                 /* implicit feedback case */
1106                 int i, bytes = 0;
1107                 struct snd_urb_ctx *in_ctx;
1108                 struct snd_usb_packet_info *out_packet;
1109 
1110                 in_ctx = urb->context;
1111 
1112                 /* Count overall packet size */
1113                 for (i = 0; i < in_ctx->packets; i++)
1114                         if (urb->iso_frame_desc[i].status == 0)
1115                                 bytes += urb->iso_frame_desc[i].actual_length;
1116 
1117                 /*
1118                  * skip empty packets. At least M-Audio's Fast Track Ultra stops
1119                  * streaming once it received a 0-byte OUT URB
1120                  */
1121                 if (bytes == 0)
1122                         return;
1123 
1124                 spin_lock_irqsave(&ep->lock, flags);
1125                 out_packet = ep->next_packet + ep->next_packet_write_pos;
1126 
1127                 /*
1128                  * Iterate through the inbound packet and prepare the lengths
1129                  * for the output packet. The OUT packet we are about to send
1130                  * will have the same amount of payload bytes per stride as the
1131                  * IN packet we just received. Since the actual size is scaled
1132                  * by the stride, use the sender stride to calculate the length
1133                  * in case the number of channels differ between the implicitly
1134                  * fed-back endpoint and the synchronizing endpoint.
1135                  */
1136 
1137                 out_packet->packets = in_ctx->packets;
1138                 for (i = 0; i < in_ctx->packets; i++) {
1139                         if (urb->iso_frame_desc[i].status == 0)
1140                                 out_packet->packet_size[i] =
1141                                         urb->iso_frame_desc[i].actual_length / sender->stride;
1142                         else
1143                                 out_packet->packet_size[i] = 0;
1144                 }
1145 
1146                 ep->next_packet_write_pos++;
1147                 ep->next_packet_write_pos %= MAX_URBS;
1148                 spin_unlock_irqrestore(&ep->lock, flags);
1149                 queue_pending_output_urbs(ep);
1150 
1151                 return;
1152         }
1153 
1154         /*
1155          * process after playback sync complete
1156          *
1157          * Full speed devices report feedback values in 10.14 format as samples
1158          * per frame, high speed devices in 16.16 format as samples per
1159          * microframe.
1160          *
1161          * Because the Audio Class 1 spec was written before USB 2.0, many high
1162          * speed devices use a wrong interpretation, some others use an
1163          * entirely different format.
1164          *
1165          * Therefore, we cannot predict what format any particular device uses
1166          * and must detect it automatically.
1167          */
1168 
1169         if (urb->iso_frame_desc[0].status != 0 ||
1170             urb->iso_frame_desc[0].actual_length < 3)
1171                 return;
1172 
1173         f = le32_to_cpup(urb->transfer_buffer);
1174         if (urb->iso_frame_desc[0].actual_length == 3)
1175                 f &= 0x00ffffff;
1176         else
1177                 f &= 0x0fffffff;
1178 
1179         if (f == 0)
1180                 return;
1181 
1182         if (unlikely(sender->tenor_fb_quirk)) {
1183                 /*
1184                  * Devices based on Tenor 8802 chipsets (TEAC UD-H01
1185                  * and others) sometimes change the feedback value
1186                  * by +/- 0x1.0000.
1187                  */
1188                 if (f < ep->freqn - 0x8000)
1189                         f += 0xf000;
1190                 else if (f > ep->freqn + 0x8000)
1191                         f -= 0xf000;
1192         } else if (unlikely(ep->freqshift == INT_MIN)) {
1193                 /*
1194                  * The first time we see a feedback value, determine its format
1195                  * by shifting it left or right until it matches the nominal
1196                  * frequency value.  This assumes that the feedback does not
1197                  * differ from the nominal value more than +50% or -25%.
1198                  */
1199                 shift = 0;
1200                 while (f < ep->freqn - ep->freqn / 4) {
1201                         f <<= 1;
1202                         shift++;
1203                 }
1204                 while (f > ep->freqn + ep->freqn / 2) {
1205                         f >>= 1;
1206                         shift--;
1207                 }
1208                 ep->freqshift = shift;
1209         } else if (ep->freqshift >= 0)
1210                 f <<= ep->freqshift;
1211         else
1212                 f >>= -ep->freqshift;
1213 
1214         if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {
1215                 /*
1216                  * If the frequency looks valid, set it.
1217                  * This value is referred to in prepare_playback_urb().
1218                  */
1219                 spin_lock_irqsave(&ep->lock, flags);
1220                 ep->freqm = f;
1221                 spin_unlock_irqrestore(&ep->lock, flags);
1222         } else {
1223                 /*
1224                  * Out of range; maybe the shift value is wrong.
1225                  * Reset it so that we autodetect again the next time.
1226                  */
1227                 ep->freqshift = INT_MIN;
1228         }
1229 }
1230 
1231 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp