24c511491b4529255bcf0fe8b7817d6189b42fe4
[pandora-kernel.git] / sound / usb / endpoint.c
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
24 #include <sound/core.h>
25 #include <sound/pcm.h>
26
27 #include "usbaudio.h"
28 #include "helper.h"
29 #include "card.h"
30 #include "endpoint.h"
31 #include "pcm.h"
32
33 /*
34  * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
35  * this will overflow at approx 524 kHz
36  */
37 static inline unsigned get_usb_full_speed_rate(unsigned int rate)
38 {
39         return ((rate << 13) + 62) / 125;
40 }
41
42 /*
43  * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
44  * this will overflow at approx 4 MHz
45  */
46 static inline unsigned get_usb_high_speed_rate(unsigned int rate)
47 {
48         return ((rate << 10) + 62) / 125;
49 }
50
51 /*
52  * unlink active urbs.
53  */
54 static int deactivate_urbs(struct snd_usb_substream *subs, int force, int can_sleep)
55 {
56         struct snd_usb_audio *chip = subs->stream->chip;
57         unsigned int i;
58         int async;
59
60         subs->running = 0;
61
62         if (!force && subs->stream->chip->shutdown) /* to be sure... */
63                 return -EBADFD;
64
65         async = !can_sleep && chip->async_unlink;
66
67         if (!async && in_interrupt())
68                 return 0;
69
70         for (i = 0; i < subs->nurbs; i++) {
71                 if (test_bit(i, &subs->active_mask)) {
72                         if (!test_and_set_bit(i, &subs->unlink_mask)) {
73                                 struct urb *u = subs->dataurb[i].urb;
74                                 if (async)
75                                         usb_unlink_urb(u);
76                                 else
77                                         usb_kill_urb(u);
78                         }
79                 }
80         }
81         if (subs->syncpipe) {
82                 for (i = 0; i < SYNC_URBS; i++) {
83                         if (test_bit(i+16, &subs->active_mask)) {
84                                 if (!test_and_set_bit(i+16, &subs->unlink_mask)) {
85                                         struct urb *u = subs->syncurb[i].urb;
86                                         if (async)
87                                                 usb_unlink_urb(u);
88                                         else
89                                                 usb_kill_urb(u);
90                                 }
91                         }
92                 }
93         }
94         return 0;
95 }
96
97
98 /*
99  * release a urb data
100  */
101 static void release_urb_ctx(struct snd_urb_ctx *u)
102 {
103         if (u->urb) {
104                 if (u->buffer_size)
105                         usb_free_coherent(u->subs->dev, u->buffer_size,
106                                         u->urb->transfer_buffer,
107                                         u->urb->transfer_dma);
108                 usb_free_urb(u->urb);
109                 u->urb = NULL;
110         }
111 }
112
113 /*
114  *  wait until all urbs are processed.
115  */
116 static int wait_clear_urbs(struct snd_usb_substream *subs)
117 {
118         unsigned long end_time = jiffies + msecs_to_jiffies(1000);
119         unsigned int i;
120         int alive;
121
122         do {
123                 alive = 0;
124                 for (i = 0; i < subs->nurbs; i++) {
125                         if (test_bit(i, &subs->active_mask))
126                                 alive++;
127                 }
128                 if (subs->syncpipe) {
129                         for (i = 0; i < SYNC_URBS; i++) {
130                                 if (test_bit(i + 16, &subs->active_mask))
131                                         alive++;
132                         }
133                 }
134                 if (! alive)
135                         break;
136                 schedule_timeout_uninterruptible(1);
137         } while (time_before(jiffies, end_time));
138         if (alive)
139                 snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);
140         return 0;
141 }
142
143 /*
144  * release a substream
145  */
146 void snd_usb_release_substream_urbs(struct snd_usb_substream *subs, int force)
147 {
148         int i;
149
150         /* stop urbs (to be sure) */
151         if (!subs->stream->chip->shutdown) {
152                 deactivate_urbs(subs, force, 1);
153                 wait_clear_urbs(subs);
154         }
155
156         for (i = 0; i < MAX_URBS; i++)
157                 release_urb_ctx(&subs->dataurb[i]);
158         for (i = 0; i < SYNC_URBS; i++)
159                 release_urb_ctx(&subs->syncurb[i]);
160         usb_free_coherent(subs->dev, SYNC_URBS * 4,
161                         subs->syncbuf, subs->sync_dma);
162         subs->syncbuf = NULL;
163         subs->nurbs = 0;
164 }
165
166 /*
167  * complete callback from data urb
168  */
169 static void snd_complete_urb(struct urb *urb)
170 {
171         struct snd_urb_ctx *ctx = urb->context;
172         struct snd_usb_substream *subs = ctx->subs;
173         struct snd_pcm_substream *substream = ctx->subs->pcm_substream;
174         int err = 0;
175
176         if ((subs->running && subs->ops.retire(subs, substream->runtime, urb)) ||
177             !subs->running || /* can be stopped during retire callback */
178             (err = subs->ops.prepare(subs, substream->runtime, urb)) < 0 ||
179             (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
180                 clear_bit(ctx->index, &subs->active_mask);
181                 if (err < 0) {
182                         snd_printd(KERN_ERR "cannot submit urb (err = %d)\n", err);
183                         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
184                 }
185         }
186 }
187
188
189 /*
190  * complete callback from sync urb
191  */
192 static void snd_complete_sync_urb(struct urb *urb)
193 {
194         struct snd_urb_ctx *ctx = urb->context;
195         struct snd_usb_substream *subs = ctx->subs;
196         struct snd_pcm_substream *substream = ctx->subs->pcm_substream;
197         int err = 0;
198
199         if ((subs->running && subs->ops.retire_sync(subs, substream->runtime, urb)) ||
200             !subs->running || /* can be stopped during retire callback */
201             (err = subs->ops.prepare_sync(subs, substream->runtime, urb)) < 0 ||
202             (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
203                 clear_bit(ctx->index + 16, &subs->active_mask);
204                 if (err < 0) {
205                         snd_printd(KERN_ERR "cannot submit sync urb (err = %d)\n", err);
206                         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
207                 }
208         }
209 }
210
211
212 /*
213  * initialize a substream for plaback/capture
214  */
215 int snd_usb_init_substream_urbs(struct snd_usb_substream *subs,
216                                 unsigned int period_bytes,
217                                 unsigned int rate,
218                                 unsigned int frame_bits)
219 {
220         unsigned int maxsize, i;
221         int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
222         unsigned int urb_packs, total_packs, packs_per_ms;
223         struct snd_usb_audio *chip = subs->stream->chip;
224
225         /* calculate the frequency in 16.16 format */
226         if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
227                 subs->freqn = get_usb_full_speed_rate(rate);
228         else
229                 subs->freqn = get_usb_high_speed_rate(rate);
230         subs->freqm = subs->freqn;
231         subs->freqshift = INT_MIN;
232         /* calculate max. frequency */
233         if (subs->maxpacksize) {
234                 /* whatever fits into a max. size packet */
235                 maxsize = subs->maxpacksize;
236                 subs->freqmax = (maxsize / (frame_bits >> 3))
237                                 << (16 - subs->datainterval);
238         } else {
239                 /* no max. packet size: just take 25% higher than nominal */
240                 subs->freqmax = subs->freqn + (subs->freqn >> 2);
241                 maxsize = ((subs->freqmax + 0xffff) * (frame_bits >> 3))
242                                 >> (16 - subs->datainterval);
243         }
244         subs->phase = 0;
245
246         if (subs->fill_max)
247                 subs->curpacksize = subs->maxpacksize;
248         else
249                 subs->curpacksize = maxsize;
250
251         if (snd_usb_get_speed(subs->dev) != USB_SPEED_FULL)
252                 packs_per_ms = 8 >> subs->datainterval;
253         else
254                 packs_per_ms = 1;
255
256         if (is_playback) {
257                 urb_packs = max(chip->nrpacks, 1);
258                 urb_packs = min(urb_packs, (unsigned int)MAX_PACKS);
259         } else
260                 urb_packs = 1;
261         urb_packs *= packs_per_ms;
262         if (subs->syncpipe)
263                 urb_packs = min(urb_packs, 1U << subs->syncinterval);
264
265         /* decide how many packets to be used */
266         if (is_playback) {
267                 unsigned int minsize, maxpacks;
268                 /* determine how small a packet can be */
269                 minsize = (subs->freqn >> (16 - subs->datainterval))
270                           * (frame_bits >> 3);
271                 /* with sync from device, assume it can be 12% lower */
272                 if (subs->syncpipe)
273                         minsize -= minsize >> 3;
274                 minsize = max(minsize, 1u);
275                 total_packs = (period_bytes + minsize - 1) / minsize;
276                 /* we need at least two URBs for queueing */
277                 if (total_packs < 2) {
278                         total_packs = 2;
279                 } else {
280                         /* and we don't want too long a queue either */
281                         maxpacks = max(MAX_QUEUE * packs_per_ms, urb_packs * 2);
282                         total_packs = min(total_packs, maxpacks);
283                 }
284         } else {
285                 while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
286                         urb_packs >>= 1;
287                 total_packs = MAX_URBS * urb_packs;
288         }
289         subs->nurbs = (total_packs + urb_packs - 1) / urb_packs;
290         if (subs->nurbs > MAX_URBS) {
291                 /* too much... */
292                 subs->nurbs = MAX_URBS;
293                 total_packs = MAX_URBS * urb_packs;
294         } else if (subs->nurbs < 2) {
295                 /* too little - we need at least two packets
296                  * to ensure contiguous playback/capture
297                  */
298                 subs->nurbs = 2;
299         }
300
301         /* allocate and initialize data urbs */
302         for (i = 0; i < subs->nurbs; i++) {
303                 struct snd_urb_ctx *u = &subs->dataurb[i];
304                 u->index = i;
305                 u->subs = subs;
306                 u->packets = (i + 1) * total_packs / subs->nurbs
307                         - i * total_packs / subs->nurbs;
308                 u->buffer_size = maxsize * u->packets;
309                 if (subs->fmt_type == UAC_FORMAT_TYPE_II)
310                         u->packets++; /* for transfer delimiter */
311                 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
312                 if (!u->urb)
313                         goto out_of_memory;
314                 u->urb->transfer_buffer =
315                         usb_alloc_coherent(subs->dev, u->buffer_size,
316                                            GFP_KERNEL, &u->urb->transfer_dma);
317                 if (!u->urb->transfer_buffer)
318                         goto out_of_memory;
319                 u->urb->pipe = subs->datapipe;
320                 u->urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
321                 u->urb->interval = 1 << subs->datainterval;
322                 u->urb->context = u;
323                 u->urb->complete = snd_complete_urb;
324         }
325
326         if (subs->syncpipe) {
327                 /* allocate and initialize sync urbs */
328                 subs->syncbuf = usb_alloc_coherent(subs->dev, SYNC_URBS * 4,
329                                                  GFP_KERNEL, &subs->sync_dma);
330                 if (!subs->syncbuf)
331                         goto out_of_memory;
332                 for (i = 0; i < SYNC_URBS; i++) {
333                         struct snd_urb_ctx *u = &subs->syncurb[i];
334                         u->index = i;
335                         u->subs = subs;
336                         u->packets = 1;
337                         u->urb = usb_alloc_urb(1, GFP_KERNEL);
338                         if (!u->urb)
339                                 goto out_of_memory;
340                         u->urb->transfer_buffer = subs->syncbuf + i * 4;
341                         u->urb->transfer_dma = subs->sync_dma + i * 4;
342                         u->urb->transfer_buffer_length = 4;
343                         u->urb->pipe = subs->syncpipe;
344                         u->urb->transfer_flags = URB_ISO_ASAP |
345                                                  URB_NO_TRANSFER_DMA_MAP;
346                         u->urb->number_of_packets = 1;
347                         u->urb->interval = 1 << subs->syncinterval;
348                         u->urb->context = u;
349                         u->urb->complete = snd_complete_sync_urb;
350                 }
351         }
352         return 0;
353
354 out_of_memory:
355         snd_usb_release_substream_urbs(subs, 0);
356         return -ENOMEM;
357 }
358
359 /*
360  * prepare urb for full speed capture sync pipe
361  *
362  * fill the length and offset of each urb descriptor.
363  * the fixed 10.14 frequency is passed through the pipe.
364  */
365 static int prepare_capture_sync_urb(struct snd_usb_substream *subs,
366                                     struct snd_pcm_runtime *runtime,
367                                     struct urb *urb)
368 {
369         unsigned char *cp = urb->transfer_buffer;
370         struct snd_urb_ctx *ctx = urb->context;
371
372         urb->dev = ctx->subs->dev; /* we need to set this at each time */
373         urb->iso_frame_desc[0].length = 3;
374         urb->iso_frame_desc[0].offset = 0;
375         cp[0] = subs->freqn >> 2;
376         cp[1] = subs->freqn >> 10;
377         cp[2] = subs->freqn >> 18;
378         return 0;
379 }
380
381 /*
382  * prepare urb for high speed capture sync pipe
383  *
384  * fill the length and offset of each urb descriptor.
385  * the fixed 12.13 frequency is passed as 16.16 through the pipe.
386  */
387 static int prepare_capture_sync_urb_hs(struct snd_usb_substream *subs,
388                                        struct snd_pcm_runtime *runtime,
389                                        struct urb *urb)
390 {
391         unsigned char *cp = urb->transfer_buffer;
392         struct snd_urb_ctx *ctx = urb->context;
393
394         urb->dev = ctx->subs->dev; /* we need to set this at each time */
395         urb->iso_frame_desc[0].length = 4;
396         urb->iso_frame_desc[0].offset = 0;
397         cp[0] = subs->freqn;
398         cp[1] = subs->freqn >> 8;
399         cp[2] = subs->freqn >> 16;
400         cp[3] = subs->freqn >> 24;
401         return 0;
402 }
403
404 /*
405  * process after capture sync complete
406  * - nothing to do
407  */
408 static int retire_capture_sync_urb(struct snd_usb_substream *subs,
409                                    struct snd_pcm_runtime *runtime,
410                                    struct urb *urb)
411 {
412         return 0;
413 }
414
415 /*
416  * prepare urb for capture data pipe
417  *
418  * fill the offset and length of each descriptor.
419  *
420  * we use a temporary buffer to write the captured data.
421  * since the length of written data is determined by host, we cannot
422  * write onto the pcm buffer directly...  the data is thus copied
423  * later at complete callback to the global buffer.
424  */
425 static int prepare_capture_urb(struct snd_usb_substream *subs,
426                                struct snd_pcm_runtime *runtime,
427                                struct urb *urb)
428 {
429         int i, offs;
430         struct snd_urb_ctx *ctx = urb->context;
431
432         offs = 0;
433         urb->dev = ctx->subs->dev; /* we need to set this at each time */
434         for (i = 0; i < ctx->packets; i++) {
435                 urb->iso_frame_desc[i].offset = offs;
436                 urb->iso_frame_desc[i].length = subs->curpacksize;
437                 offs += subs->curpacksize;
438         }
439         urb->transfer_buffer_length = offs;
440         urb->number_of_packets = ctx->packets;
441         return 0;
442 }
443
444 /*
445  * process after capture complete
446  *
447  * copy the data from each desctiptor to the pcm buffer, and
448  * update the current position.
449  */
450 static int retire_capture_urb(struct snd_usb_substream *subs,
451                               struct snd_pcm_runtime *runtime,
452                               struct urb *urb)
453 {
454         unsigned long flags;
455         unsigned char *cp;
456         int i;
457         unsigned int stride, frames, bytes, oldptr;
458         int period_elapsed = 0;
459
460         stride = runtime->frame_bits >> 3;
461
462         for (i = 0; i < urb->number_of_packets; i++) {
463                 cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
464                 if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
465                         snd_printdd("frame %d active: %d\n", i, urb->iso_frame_desc[i].status);
466                         // continue;
467                 }
468                 bytes = urb->iso_frame_desc[i].actual_length;
469                 frames = bytes / stride;
470                 if (!subs->txfr_quirk)
471                         bytes = frames * stride;
472                 if (bytes % (runtime->sample_bits >> 3) != 0) {
473 #ifdef CONFIG_SND_DEBUG_VERBOSE
474                         int oldbytes = bytes;
475 #endif
476                         bytes = frames * stride;
477                         snd_printdd(KERN_ERR "Corrected urb data len. %d->%d\n",
478                                                         oldbytes, bytes);
479                 }
480                 /* update the current pointer */
481                 spin_lock_irqsave(&subs->lock, flags);
482                 oldptr = subs->hwptr_done;
483                 subs->hwptr_done += bytes;
484                 if (subs->hwptr_done >= runtime->buffer_size * stride)
485                         subs->hwptr_done -= runtime->buffer_size * stride;
486                 frames = (bytes + (oldptr % stride)) / stride;
487                 subs->transfer_done += frames;
488                 if (subs->transfer_done >= runtime->period_size) {
489                         subs->transfer_done -= runtime->period_size;
490                         period_elapsed = 1;
491                 }
492                 spin_unlock_irqrestore(&subs->lock, flags);
493                 /* copy a data chunk */
494                 if (oldptr + bytes > runtime->buffer_size * stride) {
495                         unsigned int bytes1 =
496                                         runtime->buffer_size * stride - oldptr;
497                         memcpy(runtime->dma_area + oldptr, cp, bytes1);
498                         memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
499                 } else {
500                         memcpy(runtime->dma_area + oldptr, cp, bytes);
501                 }
502         }
503         if (period_elapsed)
504                 snd_pcm_period_elapsed(subs->pcm_substream);
505         return 0;
506 }
507
508 /*
509  * Process after capture complete when paused.  Nothing to do.
510  */
511 static int retire_paused_capture_urb(struct snd_usb_substream *subs,
512                                      struct snd_pcm_runtime *runtime,
513                                      struct urb *urb)
514 {
515         return 0;
516 }
517
518
519 /*
520  * prepare urb for playback sync pipe
521  *
522  * set up the offset and length to receive the current frequency.
523  */
524 static int prepare_playback_sync_urb(struct snd_usb_substream *subs,
525                                      struct snd_pcm_runtime *runtime,
526                                      struct urb *urb)
527 {
528         struct snd_urb_ctx *ctx = urb->context;
529
530         urb->dev = ctx->subs->dev; /* we need to set this at each time */
531         urb->iso_frame_desc[0].length = min(4u, ctx->subs->syncmaxsize);
532         urb->iso_frame_desc[0].offset = 0;
533         return 0;
534 }
535
536 /*
537  * process after playback sync complete
538  *
539  * Full speed devices report feedback values in 10.14 format as samples per
540  * frame, high speed devices in 16.16 format as samples per microframe.
541  * Because the Audio Class 1 spec was written before USB 2.0, many high speed
542  * devices use a wrong interpretation, some others use an entirely different
543  * format.  Therefore, we cannot predict what format any particular device uses
544  * and must detect it automatically.
545  */
546 static int retire_playback_sync_urb(struct snd_usb_substream *subs,
547                                     struct snd_pcm_runtime *runtime,
548                                     struct urb *urb)
549 {
550         unsigned int f;
551         int shift;
552         unsigned long flags;
553
554         if (urb->iso_frame_desc[0].status != 0 ||
555             urb->iso_frame_desc[0].actual_length < 3)
556                 return 0;
557
558         f = le32_to_cpup(urb->transfer_buffer);
559         if (urb->iso_frame_desc[0].actual_length == 3)
560                 f &= 0x00ffffff;
561         else
562                 f &= 0x0fffffff;
563         if (f == 0)
564                 return 0;
565
566         if (unlikely(subs->freqshift == INT_MIN)) {
567                 /*
568                  * The first time we see a feedback value, determine its format
569                  * by shifting it left or right until it matches the nominal
570                  * frequency value.  This assumes that the feedback does not
571                  * differ from the nominal value more than +50% or -25%.
572                  */
573                 shift = 0;
574                 while (f < subs->freqn - subs->freqn / 4) {
575                         f <<= 1;
576                         shift++;
577                 }
578                 while (f > subs->freqn + subs->freqn / 2) {
579                         f >>= 1;
580                         shift--;
581                 }
582                 subs->freqshift = shift;
583         }
584         else if (subs->freqshift >= 0)
585                 f <<= subs->freqshift;
586         else
587                 f >>= -subs->freqshift;
588
589         if (likely(f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax)) {
590                 /*
591                  * If the frequency looks valid, set it.
592                  * This value is referred to in prepare_playback_urb().
593                  */
594                 spin_lock_irqsave(&subs->lock, flags);
595                 subs->freqm = f;
596                 spin_unlock_irqrestore(&subs->lock, flags);
597         } else {
598                 /*
599                  * Out of range; maybe the shift value is wrong.
600                  * Reset it so that we autodetect again the next time.
601                  */
602                 subs->freqshift = INT_MIN;
603         }
604
605         return 0;
606 }
607
608 /* determine the number of frames in the next packet */
609 static int snd_usb_audio_next_packet_size(struct snd_usb_substream *subs)
610 {
611         if (subs->fill_max)
612                 return subs->maxframesize;
613         else {
614                 subs->phase = (subs->phase & 0xffff)
615                         + (subs->freqm << subs->datainterval);
616                 return min(subs->phase >> 16, subs->maxframesize);
617         }
618 }
619
620 /*
621  * Prepare urb for streaming before playback starts or when paused.
622  *
623  * We don't have any data, so we send silence.
624  */
625 static int prepare_nodata_playback_urb(struct snd_usb_substream *subs,
626                                        struct snd_pcm_runtime *runtime,
627                                        struct urb *urb)
628 {
629         unsigned int i, offs, counts;
630         struct snd_urb_ctx *ctx = urb->context;
631         int stride = runtime->frame_bits >> 3;
632
633         offs = 0;
634         urb->dev = ctx->subs->dev;
635         for (i = 0; i < ctx->packets; ++i) {
636                 counts = snd_usb_audio_next_packet_size(subs);
637                 urb->iso_frame_desc[i].offset = offs * stride;
638                 urb->iso_frame_desc[i].length = counts * stride;
639                 offs += counts;
640         }
641         urb->number_of_packets = ctx->packets;
642         urb->transfer_buffer_length = offs * stride;
643         memset(urb->transfer_buffer,
644                runtime->format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0,
645                offs * stride);
646         return 0;
647 }
648
649 /*
650  * prepare urb for playback data pipe
651  *
652  * Since a URB can handle only a single linear buffer, we must use double
653  * buffering when the data to be transferred overflows the buffer boundary.
654  * To avoid inconsistencies when updating hwptr_done, we use double buffering
655  * for all URBs.
656  */
657 static int prepare_playback_urb(struct snd_usb_substream *subs,
658                                 struct snd_pcm_runtime *runtime,
659                                 struct urb *urb)
660 {
661         int i, stride;
662         unsigned int counts, frames, bytes;
663         unsigned long flags;
664         int period_elapsed = 0;
665         struct snd_urb_ctx *ctx = urb->context;
666
667         stride = runtime->frame_bits >> 3;
668
669         frames = 0;
670         urb->dev = ctx->subs->dev; /* we need to set this at each time */
671         urb->number_of_packets = 0;
672         spin_lock_irqsave(&subs->lock, flags);
673         for (i = 0; i < ctx->packets; i++) {
674                 counts = snd_usb_audio_next_packet_size(subs);
675                 /* set up descriptor */
676                 urb->iso_frame_desc[i].offset = frames * stride;
677                 urb->iso_frame_desc[i].length = counts * stride;
678                 frames += counts;
679                 urb->number_of_packets++;
680                 subs->transfer_done += counts;
681                 if (subs->transfer_done >= runtime->period_size) {
682                         subs->transfer_done -= runtime->period_size;
683                         period_elapsed = 1;
684                         if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
685                                 if (subs->transfer_done > 0) {
686                                         /* FIXME: fill-max mode is not
687                                          * supported yet */
688                                         frames -= subs->transfer_done;
689                                         counts -= subs->transfer_done;
690                                         urb->iso_frame_desc[i].length =
691                                                 counts * stride;
692                                         subs->transfer_done = 0;
693                                 }
694                                 i++;
695                                 if (i < ctx->packets) {
696                                         /* add a transfer delimiter */
697                                         urb->iso_frame_desc[i].offset =
698                                                 frames * stride;
699                                         urb->iso_frame_desc[i].length = 0;
700                                         urb->number_of_packets++;
701                                 }
702                                 break;
703                         }
704                 }
705                 if (period_elapsed) /* finish at the period boundary */
706                         break;
707         }
708         bytes = frames * stride;
709         if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
710                 /* err, the transferred area goes over buffer boundary. */
711                 unsigned int bytes1 =
712                         runtime->buffer_size * stride - subs->hwptr_done;
713                 memcpy(urb->transfer_buffer,
714                        runtime->dma_area + subs->hwptr_done, bytes1);
715                 memcpy(urb->transfer_buffer + bytes1,
716                        runtime->dma_area, bytes - bytes1);
717         } else {
718                 memcpy(urb->transfer_buffer,
719                        runtime->dma_area + subs->hwptr_done, bytes);
720         }
721         subs->hwptr_done += bytes;
722         if (subs->hwptr_done >= runtime->buffer_size * stride)
723                 subs->hwptr_done -= runtime->buffer_size * stride;
724
725         /* update delay with exact number of samples queued */
726         runtime->delay = subs->last_delay;
727         runtime->delay += frames;
728         subs->last_delay = runtime->delay;
729
730         /* realign last_frame_number */
731         subs->last_frame_number = usb_get_current_frame_number(subs->dev);
732         subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
733
734         spin_unlock_irqrestore(&subs->lock, flags);
735         urb->transfer_buffer_length = bytes;
736         if (period_elapsed)
737                 snd_pcm_period_elapsed(subs->pcm_substream);
738         return 0;
739 }
740
741 /*
742  * process after playback data complete
743  * - decrease the delay count again
744  */
745 static int retire_playback_urb(struct snd_usb_substream *subs,
746                                struct snd_pcm_runtime *runtime,
747                                struct urb *urb)
748 {
749         unsigned long flags;
750         int stride = runtime->frame_bits >> 3;
751         int processed = urb->transfer_buffer_length / stride;
752         int est_delay;
753
754         spin_lock_irqsave(&subs->lock, flags);
755
756         est_delay = snd_usb_pcm_delay(subs, runtime->rate);
757         /* update delay with exact number of samples played */
758         if (processed > subs->last_delay)
759                 subs->last_delay = 0;
760         else
761                 subs->last_delay -= processed;
762         runtime->delay = subs->last_delay;
763
764         /*
765          * Report when delay estimate is off by more than 2ms.
766          * The error should be lower than 2ms since the estimate relies
767          * on two reads of a counter updated every ms.
768          */
769         if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
770                 snd_printk(KERN_DEBUG "delay: estimated %d, actual %d\n",
771                         est_delay, subs->last_delay);
772
773         spin_unlock_irqrestore(&subs->lock, flags);
774         return 0;
775 }
776
777 static const char *usb_error_string(int err)
778 {
779         switch (err) {
780         case -ENODEV:
781                 return "no device";
782         case -ENOENT:
783                 return "endpoint not enabled";
784         case -EPIPE:
785                 return "endpoint stalled";
786         case -ENOSPC:
787                 return "not enough bandwidth";
788         case -ESHUTDOWN:
789                 return "device disabled";
790         case -EHOSTUNREACH:
791                 return "device suspended";
792         case -EINVAL:
793         case -EAGAIN:
794         case -EFBIG:
795         case -EMSGSIZE:
796                 return "internal error";
797         default:
798                 return "unknown error";
799         }
800 }
801
802 /*
803  * set up and start data/sync urbs
804  */
805 static int start_urbs(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime)
806 {
807         unsigned int i;
808         int err;
809
810         if (subs->stream->chip->shutdown)
811                 return -EBADFD;
812
813         for (i = 0; i < subs->nurbs; i++) {
814                 if (snd_BUG_ON(!subs->dataurb[i].urb))
815                         return -EINVAL;
816                 if (subs->ops.prepare(subs, runtime, subs->dataurb[i].urb) < 0) {
817                         snd_printk(KERN_ERR "cannot prepare datapipe for urb %d\n", i);
818                         goto __error;
819                 }
820         }
821         if (subs->syncpipe) {
822                 for (i = 0; i < SYNC_URBS; i++) {
823                         if (snd_BUG_ON(!subs->syncurb[i].urb))
824                                 return -EINVAL;
825                         if (subs->ops.prepare_sync(subs, runtime, subs->syncurb[i].urb) < 0) {
826                                 snd_printk(KERN_ERR "cannot prepare syncpipe for urb %d\n", i);
827                                 goto __error;
828                         }
829                 }
830         }
831
832         subs->active_mask = 0;
833         subs->unlink_mask = 0;
834         subs->running = 1;
835         for (i = 0; i < subs->nurbs; i++) {
836                 err = usb_submit_urb(subs->dataurb[i].urb, GFP_ATOMIC);
837                 if (err < 0) {
838                         snd_printk(KERN_ERR "cannot submit datapipe "
839                                    "for urb %d, error %d: %s\n",
840                                    i, err, usb_error_string(err));
841                         goto __error;
842                 }
843                 set_bit(i, &subs->active_mask);
844         }
845         if (subs->syncpipe) {
846                 for (i = 0; i < SYNC_URBS; i++) {
847                         err = usb_submit_urb(subs->syncurb[i].urb, GFP_ATOMIC);
848                         if (err < 0) {
849                                 snd_printk(KERN_ERR "cannot submit syncpipe "
850                                            "for urb %d, error %d: %s\n",
851                                            i, err, usb_error_string(err));
852                                 goto __error;
853                         }
854                         set_bit(i + 16, &subs->active_mask);
855                 }
856         }
857         return 0;
858
859  __error:
860         // snd_pcm_stop(subs->pcm_substream, SNDRV_PCM_STATE_XRUN);
861         deactivate_urbs(subs, 0, 0);
862         return -EPIPE;
863 }
864
865
866 /*
867  */
868 static struct snd_urb_ops audio_urb_ops[2] = {
869         {
870                 .prepare =      prepare_nodata_playback_urb,
871                 .retire =       retire_playback_urb,
872                 .prepare_sync = prepare_playback_sync_urb,
873                 .retire_sync =  retire_playback_sync_urb,
874         },
875         {
876                 .prepare =      prepare_capture_urb,
877                 .retire =       retire_capture_urb,
878                 .prepare_sync = prepare_capture_sync_urb,
879                 .retire_sync =  retire_capture_sync_urb,
880         },
881 };
882
883 /*
884  * initialize the substream instance.
885  */
886
887 void snd_usb_init_substream(struct snd_usb_stream *as,
888                             int stream, struct audioformat *fp)
889 {
890         struct snd_usb_substream *subs = &as->substream[stream];
891
892         INIT_LIST_HEAD(&subs->fmt_list);
893         spin_lock_init(&subs->lock);
894
895         subs->stream = as;
896         subs->direction = stream;
897         subs->dev = as->chip->dev;
898         subs->txfr_quirk = as->chip->txfr_quirk;
899         subs->ops = audio_urb_ops[stream];
900         subs->speed = snd_usb_get_speed(subs->dev);
901         if (subs->speed >= USB_SPEED_HIGH)
902                 subs->ops.prepare_sync = prepare_capture_sync_urb_hs;
903
904         snd_usb_set_pcm_ops(as->pcm, stream);
905
906         list_add_tail(&fp->list, &subs->fmt_list);
907         subs->formats |= fp->formats;
908         subs->endpoint = fp->endpoint;
909         subs->num_formats++;
910         subs->fmt_type = fp->fmt_type;
911 }
912
913 int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream, int cmd)
914 {
915         struct snd_usb_substream *subs = substream->runtime->private_data;
916
917         switch (cmd) {
918         case SNDRV_PCM_TRIGGER_START:
919         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
920                 subs->ops.prepare = prepare_playback_urb;
921                 return 0;
922         case SNDRV_PCM_TRIGGER_STOP:
923                 return deactivate_urbs(subs, 0, 0);
924         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
925                 subs->ops.prepare = prepare_nodata_playback_urb;
926                 return 0;
927         }
928
929         return -EINVAL;
930 }
931
932 int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream, int cmd)
933 {
934         struct snd_usb_substream *subs = substream->runtime->private_data;
935
936         switch (cmd) {
937         case SNDRV_PCM_TRIGGER_START:
938                 subs->ops.retire = retire_capture_urb;
939                 return start_urbs(subs, substream->runtime);
940         case SNDRV_PCM_TRIGGER_STOP:
941                 return deactivate_urbs(subs, 0, 0);
942         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
943                 subs->ops.retire = retire_paused_capture_urb;
944                 return 0;
945         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
946                 subs->ops.retire = retire_capture_urb;
947                 return 0;
948         }
949
950         return -EINVAL;
951 }
952
953 int snd_usb_substream_prepare(struct snd_usb_substream *subs,
954                               struct snd_pcm_runtime *runtime)
955 {
956         /* clear urbs (to be sure) */
957         deactivate_urbs(subs, 0, 1);
958         wait_clear_urbs(subs);
959
960         /* for playback, submit the URBs now; otherwise, the first hwptr_done
961          * updates for all URBs would happen at the same time when starting */
962         if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
963                 subs->ops.prepare = prepare_nodata_playback_urb;
964                 return start_urbs(subs, runtime);
965         }
966
967         return 0;
968 }
969