ALSA: usb-audio: automatically detect feedback format
[linux-2.6.git] / sound / usb / urb.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/usb.h>
21 #include <linux/usb/audio.h>
22
23 #include <sound/core.h>
24 #include <sound/pcm.h>
25
26 #include "usbaudio.h"
27 #include "helper.h"
28 #include "card.h"
29 #include "urb.h"
30 #include "pcm.h"
31
32 /*
33  * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
34  * this will overflow at approx 524 kHz
35  */
36 static inline unsigned get_usb_full_speed_rate(unsigned int rate)
37 {
38         return ((rate << 13) + 62) / 125;
39 }
40
41 /*
42  * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
43  * this will overflow at approx 4 MHz
44  */
45 static inline unsigned get_usb_high_speed_rate(unsigned int rate)
46 {
47         return ((rate << 10) + 62) / 125;
48 }
49
50 /*
51  * unlink active urbs.
52  */
53 static int deactivate_urbs(struct snd_usb_substream *subs, int force, int can_sleep)
54 {
55         struct snd_usb_audio *chip = subs->stream->chip;
56         unsigned int i;
57         int async;
58
59         subs->running = 0;
60
61         if (!force && subs->stream->chip->shutdown) /* to be sure... */
62                 return -EBADFD;
63
64         async = !can_sleep && chip->async_unlink;
65
66         if (!async && in_interrupt())
67                 return 0;
68
69         for (i = 0; i < subs->nurbs; i++) {
70                 if (test_bit(i, &subs->active_mask)) {
71                         if (!test_and_set_bit(i, &subs->unlink_mask)) {
72                                 struct urb *u = subs->dataurb[i].urb;
73                                 if (async)
74                                         usb_unlink_urb(u);
75                                 else
76                                         usb_kill_urb(u);
77                         }
78                 }
79         }
80         if (subs->syncpipe) {
81                 for (i = 0; i < SYNC_URBS; i++) {
82                         if (test_bit(i+16, &subs->active_mask)) {
83                                 if (!test_and_set_bit(i+16, &subs->unlink_mask)) {
84                                         struct urb *u = subs->syncurb[i].urb;
85                                         if (async)
86                                                 usb_unlink_urb(u);
87                                         else
88                                                 usb_kill_urb(u);
89                                 }
90                         }
91                 }
92         }
93         return 0;
94 }
95
96
97 /*
98  * release a urb data
99  */
100 static void release_urb_ctx(struct snd_urb_ctx *u)
101 {
102         if (u->urb) {
103                 if (u->buffer_size)
104                         usb_free_coherent(u->subs->dev, u->buffer_size,
105                                         u->urb->transfer_buffer,
106                                         u->urb->transfer_dma);
107                 usb_free_urb(u->urb);
108                 u->urb = NULL;
109         }
110 }
111
112 /*
113  *  wait until all urbs are processed.
114  */
115 static int wait_clear_urbs(struct snd_usb_substream *subs)
116 {
117         unsigned long end_time = jiffies + msecs_to_jiffies(1000);
118         unsigned int i;
119         int alive;
120
121         do {
122                 alive = 0;
123                 for (i = 0; i < subs->nurbs; i++) {
124                         if (test_bit(i, &subs->active_mask))
125                                 alive++;
126                 }
127                 if (subs->syncpipe) {
128                         for (i = 0; i < SYNC_URBS; i++) {
129                                 if (test_bit(i + 16, &subs->active_mask))
130                                         alive++;
131                         }
132                 }
133                 if (! alive)
134                         break;
135                 schedule_timeout_uninterruptible(1);
136         } while (time_before(jiffies, end_time));
137         if (alive)
138                 snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);
139         return 0;
140 }
141
142 /*
143  * release a substream
144  */
145 void snd_usb_release_substream_urbs(struct snd_usb_substream *subs, int force)
146 {
147         int i;
148
149         /* stop urbs (to be sure) */
150         deactivate_urbs(subs, force, 1);
151         wait_clear_urbs(subs);
152
153         for (i = 0; i < MAX_URBS; i++)
154                 release_urb_ctx(&subs->dataurb[i]);
155         for (i = 0; i < SYNC_URBS; i++)
156                 release_urb_ctx(&subs->syncurb[i]);
157         usb_free_coherent(subs->dev, SYNC_URBS * 4,
158                         subs->syncbuf, subs->sync_dma);
159         subs->syncbuf = NULL;
160         subs->nurbs = 0;
161 }
162
163 /*
164  * complete callback from data urb
165  */
166 static void snd_complete_urb(struct urb *urb)
167 {
168         struct snd_urb_ctx *ctx = urb->context;
169         struct snd_usb_substream *subs = ctx->subs;
170         struct snd_pcm_substream *substream = ctx->subs->pcm_substream;
171         int err = 0;
172
173         if ((subs->running && subs->ops.retire(subs, substream->runtime, urb)) ||
174             !subs->running || /* can be stopped during retire callback */
175             (err = subs->ops.prepare(subs, substream->runtime, urb)) < 0 ||
176             (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
177                 clear_bit(ctx->index, &subs->active_mask);
178                 if (err < 0) {
179                         snd_printd(KERN_ERR "cannot submit urb (err = %d)\n", err);
180                         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
181                 }
182         }
183 }
184
185
186 /*
187  * complete callback from sync urb
188  */
189 static void snd_complete_sync_urb(struct urb *urb)
190 {
191         struct snd_urb_ctx *ctx = urb->context;
192         struct snd_usb_substream *subs = ctx->subs;
193         struct snd_pcm_substream *substream = ctx->subs->pcm_substream;
194         int err = 0;
195
196         if ((subs->running && subs->ops.retire_sync(subs, substream->runtime, urb)) ||
197             !subs->running || /* can be stopped during retire callback */
198             (err = subs->ops.prepare_sync(subs, substream->runtime, urb)) < 0 ||
199             (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
200                 clear_bit(ctx->index + 16, &subs->active_mask);
201                 if (err < 0) {
202                         snd_printd(KERN_ERR "cannot submit sync urb (err = %d)\n", err);
203                         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
204                 }
205         }
206 }
207
208
209 /*
210  * initialize a substream for plaback/capture
211  */
212 int snd_usb_init_substream_urbs(struct snd_usb_substream *subs,
213                                 unsigned int period_bytes,
214                                 unsigned int rate,
215                                 unsigned int frame_bits)
216 {
217         unsigned int maxsize, i;
218         int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
219         unsigned int urb_packs, total_packs, packs_per_ms;
220         struct snd_usb_audio *chip = subs->stream->chip;
221
222         /* calculate the frequency in 16.16 format */
223         if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
224                 subs->freqn = get_usb_full_speed_rate(rate);
225         else
226                 subs->freqn = get_usb_high_speed_rate(rate);
227         subs->freqm = subs->freqn;
228         subs->freqshift = INT_MIN;
229         /* calculate max. frequency */
230         if (subs->maxpacksize) {
231                 /* whatever fits into a max. size packet */
232                 maxsize = subs->maxpacksize;
233                 subs->freqmax = (maxsize / (frame_bits >> 3))
234                                 << (16 - subs->datainterval);
235         } else {
236                 /* no max. packet size: just take 25% higher than nominal */
237                 subs->freqmax = subs->freqn + (subs->freqn >> 2);
238                 maxsize = ((subs->freqmax + 0xffff) * (frame_bits >> 3))
239                                 >> (16 - subs->datainterval);
240         }
241         subs->phase = 0;
242
243         if (subs->fill_max)
244                 subs->curpacksize = subs->maxpacksize;
245         else
246                 subs->curpacksize = maxsize;
247
248         if (snd_usb_get_speed(subs->dev) != USB_SPEED_FULL)
249                 packs_per_ms = 8 >> subs->datainterval;
250         else
251                 packs_per_ms = 1;
252
253         if (is_playback) {
254                 urb_packs = max(chip->nrpacks, 1);
255                 urb_packs = min(urb_packs, (unsigned int)MAX_PACKS);
256         } else
257                 urb_packs = 1;
258         urb_packs *= packs_per_ms;
259         if (subs->syncpipe)
260                 urb_packs = min(urb_packs, 1U << subs->syncinterval);
261
262         /* decide how many packets to be used */
263         if (is_playback) {
264                 unsigned int minsize, maxpacks;
265                 /* determine how small a packet can be */
266                 minsize = (subs->freqn >> (16 - subs->datainterval))
267                           * (frame_bits >> 3);
268                 /* with sync from device, assume it can be 12% lower */
269                 if (subs->syncpipe)
270                         minsize -= minsize >> 3;
271                 minsize = max(minsize, 1u);
272                 total_packs = (period_bytes + minsize - 1) / minsize;
273                 /* we need at least two URBs for queueing */
274                 if (total_packs < 2) {
275                         total_packs = 2;
276                 } else {
277                         /* and we don't want too long a queue either */
278                         maxpacks = max(MAX_QUEUE * packs_per_ms, urb_packs * 2);
279                         total_packs = min(total_packs, maxpacks);
280                 }
281         } else {
282                 while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
283                         urb_packs >>= 1;
284                 total_packs = MAX_URBS * urb_packs;
285         }
286         subs->nurbs = (total_packs + urb_packs - 1) / urb_packs;
287         if (subs->nurbs > MAX_URBS) {
288                 /* too much... */
289                 subs->nurbs = MAX_URBS;
290                 total_packs = MAX_URBS * urb_packs;
291         } else if (subs->nurbs < 2) {
292                 /* too little - we need at least two packets
293                  * to ensure contiguous playback/capture
294                  */
295                 subs->nurbs = 2;
296         }
297
298         /* allocate and initialize data urbs */
299         for (i = 0; i < subs->nurbs; i++) {
300                 struct snd_urb_ctx *u = &subs->dataurb[i];
301                 u->index = i;
302                 u->subs = subs;
303                 u->packets = (i + 1) * total_packs / subs->nurbs
304                         - i * total_packs / subs->nurbs;
305                 u->buffer_size = maxsize * u->packets;
306                 if (subs->fmt_type == UAC_FORMAT_TYPE_II)
307                         u->packets++; /* for transfer delimiter */
308                 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
309                 if (!u->urb)
310                         goto out_of_memory;
311                 u->urb->transfer_buffer =
312                         usb_alloc_coherent(subs->dev, u->buffer_size,
313                                            GFP_KERNEL, &u->urb->transfer_dma);
314                 if (!u->urb->transfer_buffer)
315                         goto out_of_memory;
316                 u->urb->pipe = subs->datapipe;
317                 u->urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
318                 u->urb->interval = 1 << subs->datainterval;
319                 u->urb->context = u;
320                 u->urb->complete = snd_complete_urb;
321         }
322
323         if (subs->syncpipe) {
324                 /* allocate and initialize sync urbs */
325                 subs->syncbuf = usb_alloc_coherent(subs->dev, SYNC_URBS * 4,
326                                                  GFP_KERNEL, &subs->sync_dma);
327                 if (!subs->syncbuf)
328                         goto out_of_memory;
329                 for (i = 0; i < SYNC_URBS; i++) {
330                         struct snd_urb_ctx *u = &subs->syncurb[i];
331                         u->index = i;
332                         u->subs = subs;
333                         u->packets = 1;
334                         u->urb = usb_alloc_urb(1, GFP_KERNEL);
335                         if (!u->urb)
336                                 goto out_of_memory;
337                         u->urb->transfer_buffer = subs->syncbuf + i * 4;
338                         u->urb->transfer_dma = subs->sync_dma + i * 4;
339                         u->urb->transfer_buffer_length = 4;
340                         u->urb->pipe = subs->syncpipe;
341                         u->urb->transfer_flags = URB_ISO_ASAP |
342                                                  URB_NO_TRANSFER_DMA_MAP;
343                         u->urb->number_of_packets = 1;
344                         u->urb->interval = 1 << subs->syncinterval;
345                         u->urb->context = u;
346                         u->urb->complete = snd_complete_sync_urb;
347                 }
348         }
349         return 0;
350
351 out_of_memory:
352         snd_usb_release_substream_urbs(subs, 0);
353         return -ENOMEM;
354 }
355
356 /*
357  * prepare urb for full speed capture sync pipe
358  *
359  * fill the length and offset of each urb descriptor.
360  * the fixed 10.14 frequency is passed through the pipe.
361  */
362 static int prepare_capture_sync_urb(struct snd_usb_substream *subs,
363                                     struct snd_pcm_runtime *runtime,
364                                     struct urb *urb)
365 {
366         unsigned char *cp = urb->transfer_buffer;
367         struct snd_urb_ctx *ctx = urb->context;
368
369         urb->dev = ctx->subs->dev; /* we need to set this at each time */
370         urb->iso_frame_desc[0].length = 3;
371         urb->iso_frame_desc[0].offset = 0;
372         cp[0] = subs->freqn >> 2;
373         cp[1] = subs->freqn >> 10;
374         cp[2] = subs->freqn >> 18;
375         return 0;
376 }
377
378 /*
379  * prepare urb for high speed capture sync pipe
380  *
381  * fill the length and offset of each urb descriptor.
382  * the fixed 12.13 frequency is passed as 16.16 through the pipe.
383  */
384 static int prepare_capture_sync_urb_hs(struct snd_usb_substream *subs,
385                                        struct snd_pcm_runtime *runtime,
386                                        struct urb *urb)
387 {
388         unsigned char *cp = urb->transfer_buffer;
389         struct snd_urb_ctx *ctx = urb->context;
390
391         urb->dev = ctx->subs->dev; /* we need to set this at each time */
392         urb->iso_frame_desc[0].length = 4;
393         urb->iso_frame_desc[0].offset = 0;
394         cp[0] = subs->freqn;
395         cp[1] = subs->freqn >> 8;
396         cp[2] = subs->freqn >> 16;
397         cp[3] = subs->freqn >> 24;
398         return 0;
399 }
400
401 /*
402  * process after capture sync complete
403  * - nothing to do
404  */
405 static int retire_capture_sync_urb(struct snd_usb_substream *subs,
406                                    struct snd_pcm_runtime *runtime,
407                                    struct urb *urb)
408 {
409         return 0;
410 }
411
412 /*
413  * prepare urb for capture data pipe
414  *
415  * fill the offset and length of each descriptor.
416  *
417  * we use a temporary buffer to write the captured data.
418  * since the length of written data is determined by host, we cannot
419  * write onto the pcm buffer directly...  the data is thus copied
420  * later at complete callback to the global buffer.
421  */
422 static int prepare_capture_urb(struct snd_usb_substream *subs,
423                                struct snd_pcm_runtime *runtime,
424                                struct urb *urb)
425 {
426         int i, offs;
427         struct snd_urb_ctx *ctx = urb->context;
428
429         offs = 0;
430         urb->dev = ctx->subs->dev; /* we need to set this at each time */
431         for (i = 0; i < ctx->packets; i++) {
432                 urb->iso_frame_desc[i].offset = offs;
433                 urb->iso_frame_desc[i].length = subs->curpacksize;
434                 offs += subs->curpacksize;
435         }
436         urb->transfer_buffer_length = offs;
437         urb->number_of_packets = ctx->packets;
438         return 0;
439 }
440
441 /*
442  * process after capture complete
443  *
444  * copy the data from each desctiptor to the pcm buffer, and
445  * update the current position.
446  */
447 static int retire_capture_urb(struct snd_usb_substream *subs,
448                               struct snd_pcm_runtime *runtime,
449                               struct urb *urb)
450 {
451         unsigned long flags;
452         unsigned char *cp;
453         int i;
454         unsigned int stride, frames, bytes, oldptr;
455         int period_elapsed = 0;
456
457         stride = runtime->frame_bits >> 3;
458
459         for (i = 0; i < urb->number_of_packets; i++) {
460                 cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
461                 if (urb->iso_frame_desc[i].status) {
462                         snd_printd(KERN_ERR "frame %d active: %d\n", i, urb->iso_frame_desc[i].status);
463                         // continue;
464                 }
465                 bytes = urb->iso_frame_desc[i].actual_length;
466                 frames = bytes / stride;
467                 if (!subs->txfr_quirk)
468                         bytes = frames * stride;
469                 if (bytes % (runtime->sample_bits >> 3) != 0) {
470 #ifdef CONFIG_SND_DEBUG_VERBOSE
471                         int oldbytes = bytes;
472 #endif
473                         bytes = frames * stride;
474                         snd_printdd(KERN_ERR "Corrected urb data len. %d->%d\n",
475                                                         oldbytes, bytes);
476                 }
477                 /* update the current pointer */
478                 spin_lock_irqsave(&subs->lock, flags);
479                 oldptr = subs->hwptr_done;
480                 subs->hwptr_done += bytes;
481                 if (subs->hwptr_done >= runtime->buffer_size * stride)
482                         subs->hwptr_done -= runtime->buffer_size * stride;
483                 frames = (bytes + (oldptr % stride)) / stride;
484                 subs->transfer_done += frames;
485                 if (subs->transfer_done >= runtime->period_size) {
486                         subs->transfer_done -= runtime->period_size;
487                         period_elapsed = 1;
488                 }
489                 spin_unlock_irqrestore(&subs->lock, flags);
490                 /* copy a data chunk */
491                 if (oldptr + bytes > runtime->buffer_size * stride) {
492                         unsigned int bytes1 =
493                                         runtime->buffer_size * stride - oldptr;
494                         memcpy(runtime->dma_area + oldptr, cp, bytes1);
495                         memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
496                 } else {
497                         memcpy(runtime->dma_area + oldptr, cp, bytes);
498                 }
499         }
500         if (period_elapsed)
501                 snd_pcm_period_elapsed(subs->pcm_substream);
502         return 0;
503 }
504
505 /*
506  * Process after capture complete when paused.  Nothing to do.
507  */
508 static int retire_paused_capture_urb(struct snd_usb_substream *subs,
509                                      struct snd_pcm_runtime *runtime,
510                                      struct urb *urb)
511 {
512         return 0;
513 }
514
515
516 /*
517  * prepare urb for playback sync pipe
518  *
519  * set up the offset and length to receive the current frequency.
520  */
521 static int prepare_playback_sync_urb(struct snd_usb_substream *subs,
522                                      struct snd_pcm_runtime *runtime,
523                                      struct urb *urb)
524 {
525         struct snd_urb_ctx *ctx = urb->context;
526
527         urb->dev = ctx->subs->dev; /* we need to set this at each time */
528         urb->iso_frame_desc[0].length = min(4u, ctx->subs->syncmaxsize);
529         urb->iso_frame_desc[0].offset = 0;
530         return 0;
531 }
532
533 /*
534  * process after playback sync complete
535  *
536  * Full speed devices report feedback values in 10.14 format as samples per
537  * frame, high speed devices in 16.16 format as samples per microframe.
538  * Because the Audio Class 1 spec was written before USB 2.0, many high speed
539  * devices use a wrong interpretation, some others use an entirely different
540  * format.  Therefore, we cannot predict what format any particular device uses
541  * and must detect it automatically.
542  */
543 static int retire_playback_sync_urb(struct snd_usb_substream *subs,
544                                     struct snd_pcm_runtime *runtime,
545                                     struct urb *urb)
546 {
547         unsigned int f;
548         int shift;
549         unsigned long flags;
550
551         if (urb->iso_frame_desc[0].status != 0 ||
552             urb->iso_frame_desc[0].actual_length < 3)
553                 return 0;
554
555         f = le32_to_cpup(urb->transfer_buffer);
556         if (urb->iso_frame_desc[0].actual_length == 3)
557                 f &= 0x00ffffff;
558         else
559                 f &= 0x0fffffff;
560         if (f == 0)
561                 return 0;
562
563         if (unlikely(subs->freqshift == INT_MIN)) {
564                 /*
565                  * The first time we see a feedback value, determine its format
566                  * by shifting it left or right until it matches the nominal
567                  * frequency value.  This assumes that the feedback does not
568                  * differ from the nominal value more than +50% or -25%.
569                  */
570                 shift = 0;
571                 while (f < subs->freqn - subs->freqn / 4) {
572                         f <<= 1;
573                         shift++;
574                 }
575                 while (f > subs->freqn + subs->freqn / 2) {
576                         f >>= 1;
577                         shift--;
578                 }
579                 subs->freqshift = shift;
580         }
581         else if (subs->freqshift >= 0)
582                 f <<= subs->freqshift;
583         else
584                 f >>= -subs->freqshift;
585
586         if (likely(f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax)) {
587                 /*
588                  * If the frequency looks valid, set it.
589                  * This value is referred to in prepare_playback_urb().
590                  */
591                 spin_lock_irqsave(&subs->lock, flags);
592                 subs->freqm = f;
593                 spin_unlock_irqrestore(&subs->lock, flags);
594         } else {
595                 /*
596                  * Out of range; maybe the shift value is wrong.
597                  * Reset it so that we autodetect again the next time.
598                  */
599                 subs->freqshift = INT_MIN;
600         }
601
602         return 0;
603 }
604
605 /* determine the number of frames in the next packet */
606 static int snd_usb_audio_next_packet_size(struct snd_usb_substream *subs)
607 {
608         if (subs->fill_max)
609                 return subs->maxframesize;
610         else {
611                 subs->phase = (subs->phase & 0xffff)
612                         + (subs->freqm << subs->datainterval);
613                 return min(subs->phase >> 16, subs->maxframesize);
614         }
615 }
616
617 /*
618  * Prepare urb for streaming before playback starts or when paused.
619  *
620  * We don't have any data, so we send silence.
621  */
622 static int prepare_nodata_playback_urb(struct snd_usb_substream *subs,
623                                        struct snd_pcm_runtime *runtime,
624                                        struct urb *urb)
625 {
626         unsigned int i, offs, counts;
627         struct snd_urb_ctx *ctx = urb->context;
628         int stride = runtime->frame_bits >> 3;
629
630         offs = 0;
631         urb->dev = ctx->subs->dev;
632         for (i = 0; i < ctx->packets; ++i) {
633                 counts = snd_usb_audio_next_packet_size(subs);
634                 urb->iso_frame_desc[i].offset = offs * stride;
635                 urb->iso_frame_desc[i].length = counts * stride;
636                 offs += counts;
637         }
638         urb->number_of_packets = ctx->packets;
639         urb->transfer_buffer_length = offs * stride;
640         memset(urb->transfer_buffer,
641                runtime->format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0,
642                offs * stride);
643         return 0;
644 }
645
646 /*
647  * prepare urb for playback data pipe
648  *
649  * Since a URB can handle only a single linear buffer, we must use double
650  * buffering when the data to be transferred overflows the buffer boundary.
651  * To avoid inconsistencies when updating hwptr_done, we use double buffering
652  * for all URBs.
653  */
654 static int prepare_playback_urb(struct snd_usb_substream *subs,
655                                 struct snd_pcm_runtime *runtime,
656                                 struct urb *urb)
657 {
658         int i, stride;
659         unsigned int counts, frames, bytes;
660         unsigned long flags;
661         int period_elapsed = 0;
662         struct snd_urb_ctx *ctx = urb->context;
663
664         stride = runtime->frame_bits >> 3;
665
666         frames = 0;
667         urb->dev = ctx->subs->dev; /* we need to set this at each time */
668         urb->number_of_packets = 0;
669         spin_lock_irqsave(&subs->lock, flags);
670         for (i = 0; i < ctx->packets; i++) {
671                 counts = snd_usb_audio_next_packet_size(subs);
672                 /* set up descriptor */
673                 urb->iso_frame_desc[i].offset = frames * stride;
674                 urb->iso_frame_desc[i].length = counts * stride;
675                 frames += counts;
676                 urb->number_of_packets++;
677                 subs->transfer_done += counts;
678                 if (subs->transfer_done >= runtime->period_size) {
679                         subs->transfer_done -= runtime->period_size;
680                         period_elapsed = 1;
681                         if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
682                                 if (subs->transfer_done > 0) {
683                                         /* FIXME: fill-max mode is not
684                                          * supported yet */
685                                         frames -= subs->transfer_done;
686                                         counts -= subs->transfer_done;
687                                         urb->iso_frame_desc[i].length =
688                                                 counts * stride;
689                                         subs->transfer_done = 0;
690                                 }
691                                 i++;
692                                 if (i < ctx->packets) {
693                                         /* add a transfer delimiter */
694                                         urb->iso_frame_desc[i].offset =
695                                                 frames * stride;
696                                         urb->iso_frame_desc[i].length = 0;
697                                         urb->number_of_packets++;
698                                 }
699                                 break;
700                         }
701                 }
702                 if (period_elapsed) /* finish at the period boundary */
703                         break;
704         }
705         bytes = frames * stride;
706         if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
707                 /* err, the transferred area goes over buffer boundary. */
708                 unsigned int bytes1 =
709                         runtime->buffer_size * stride - subs->hwptr_done;
710                 memcpy(urb->transfer_buffer,
711                        runtime->dma_area + subs->hwptr_done, bytes1);
712                 memcpy(urb->transfer_buffer + bytes1,
713                        runtime->dma_area, bytes - bytes1);
714         } else {
715                 memcpy(urb->transfer_buffer,
716                        runtime->dma_area + subs->hwptr_done, bytes);
717         }
718         subs->hwptr_done += bytes;
719         if (subs->hwptr_done >= runtime->buffer_size * stride)
720                 subs->hwptr_done -= runtime->buffer_size * stride;
721         runtime->delay += frames;
722         spin_unlock_irqrestore(&subs->lock, flags);
723         urb->transfer_buffer_length = bytes;
724         if (period_elapsed)
725                 snd_pcm_period_elapsed(subs->pcm_substream);
726         return 0;
727 }
728
729 /*
730  * process after playback data complete
731  * - decrease the delay count again
732  */
733 static int retire_playback_urb(struct snd_usb_substream *subs,
734                                struct snd_pcm_runtime *runtime,
735                                struct urb *urb)
736 {
737         unsigned long flags;
738         int stride = runtime->frame_bits >> 3;
739         int processed = urb->transfer_buffer_length / stride;
740
741         spin_lock_irqsave(&subs->lock, flags);
742         if (processed > runtime->delay)
743                 runtime->delay = 0;
744         else
745                 runtime->delay -= processed;
746         spin_unlock_irqrestore(&subs->lock, flags);
747         return 0;
748 }
749
750 static const char *usb_error_string(int err)
751 {
752         switch (err) {
753         case -ENODEV:
754                 return "no device";
755         case -ENOENT:
756                 return "endpoint not enabled";
757         case -EPIPE:
758                 return "endpoint stalled";
759         case -ENOSPC:
760                 return "not enough bandwidth";
761         case -ESHUTDOWN:
762                 return "device disabled";
763         case -EHOSTUNREACH:
764                 return "device suspended";
765         case -EINVAL:
766         case -EAGAIN:
767         case -EFBIG:
768         case -EMSGSIZE:
769                 return "internal error";
770         default:
771                 return "unknown error";
772         }
773 }
774
775 /*
776  * set up and start data/sync urbs
777  */
778 static int start_urbs(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime)
779 {
780         unsigned int i;
781         int err;
782
783         if (subs->stream->chip->shutdown)
784                 return -EBADFD;
785
786         for (i = 0; i < subs->nurbs; i++) {
787                 if (snd_BUG_ON(!subs->dataurb[i].urb))
788                         return -EINVAL;
789                 if (subs->ops.prepare(subs, runtime, subs->dataurb[i].urb) < 0) {
790                         snd_printk(KERN_ERR "cannot prepare datapipe for urb %d\n", i);
791                         goto __error;
792                 }
793         }
794         if (subs->syncpipe) {
795                 for (i = 0; i < SYNC_URBS; i++) {
796                         if (snd_BUG_ON(!subs->syncurb[i].urb))
797                                 return -EINVAL;
798                         if (subs->ops.prepare_sync(subs, runtime, subs->syncurb[i].urb) < 0) {
799                                 snd_printk(KERN_ERR "cannot prepare syncpipe for urb %d\n", i);
800                                 goto __error;
801                         }
802                 }
803         }
804
805         subs->active_mask = 0;
806         subs->unlink_mask = 0;
807         subs->running = 1;
808         for (i = 0; i < subs->nurbs; i++) {
809                 err = usb_submit_urb(subs->dataurb[i].urb, GFP_ATOMIC);
810                 if (err < 0) {
811                         snd_printk(KERN_ERR "cannot submit datapipe "
812                                    "for urb %d, error %d: %s\n",
813                                    i, err, usb_error_string(err));
814                         goto __error;
815                 }
816                 set_bit(i, &subs->active_mask);
817         }
818         if (subs->syncpipe) {
819                 for (i = 0; i < SYNC_URBS; i++) {
820                         err = usb_submit_urb(subs->syncurb[i].urb, GFP_ATOMIC);
821                         if (err < 0) {
822                                 snd_printk(KERN_ERR "cannot submit syncpipe "
823                                            "for urb %d, error %d: %s\n",
824                                            i, err, usb_error_string(err));
825                                 goto __error;
826                         }
827                         set_bit(i + 16, &subs->active_mask);
828                 }
829         }
830         return 0;
831
832  __error:
833         // snd_pcm_stop(subs->pcm_substream, SNDRV_PCM_STATE_XRUN);
834         deactivate_urbs(subs, 0, 0);
835         return -EPIPE;
836 }
837
838
839 /*
840  */
841 static struct snd_urb_ops audio_urb_ops[2] = {
842         {
843                 .prepare =      prepare_nodata_playback_urb,
844                 .retire =       retire_playback_urb,
845                 .prepare_sync = prepare_playback_sync_urb,
846                 .retire_sync =  retire_playback_sync_urb,
847         },
848         {
849                 .prepare =      prepare_capture_urb,
850                 .retire =       retire_capture_urb,
851                 .prepare_sync = prepare_capture_sync_urb,
852                 .retire_sync =  retire_capture_sync_urb,
853         },
854 };
855
856 /*
857  * initialize the substream instance.
858  */
859
860 void snd_usb_init_substream(struct snd_usb_stream *as,
861                             int stream, struct audioformat *fp)
862 {
863         struct snd_usb_substream *subs = &as->substream[stream];
864
865         INIT_LIST_HEAD(&subs->fmt_list);
866         spin_lock_init(&subs->lock);
867
868         subs->stream = as;
869         subs->direction = stream;
870         subs->dev = as->chip->dev;
871         subs->txfr_quirk = as->chip->txfr_quirk;
872         subs->ops = audio_urb_ops[stream];
873         if (snd_usb_get_speed(subs->dev) >= USB_SPEED_HIGH)
874                 subs->ops.prepare_sync = prepare_capture_sync_urb_hs;
875
876         snd_usb_set_pcm_ops(as->pcm, stream);
877
878         list_add_tail(&fp->list, &subs->fmt_list);
879         subs->formats |= fp->formats;
880         subs->endpoint = fp->endpoint;
881         subs->num_formats++;
882         subs->fmt_type = fp->fmt_type;
883 }
884
885 int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream, int cmd)
886 {
887         struct snd_usb_substream *subs = substream->runtime->private_data;
888
889         switch (cmd) {
890         case SNDRV_PCM_TRIGGER_START:
891         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
892                 subs->ops.prepare = prepare_playback_urb;
893                 return 0;
894         case SNDRV_PCM_TRIGGER_STOP:
895                 return deactivate_urbs(subs, 0, 0);
896         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
897                 subs->ops.prepare = prepare_nodata_playback_urb;
898                 return 0;
899         }
900
901         return -EINVAL;
902 }
903
904 int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream, int cmd)
905 {
906         struct snd_usb_substream *subs = substream->runtime->private_data;
907
908         switch (cmd) {
909         case SNDRV_PCM_TRIGGER_START:
910                 subs->ops.retire = retire_capture_urb;
911                 return start_urbs(subs, substream->runtime);
912         case SNDRV_PCM_TRIGGER_STOP:
913                 return deactivate_urbs(subs, 0, 0);
914         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
915                 subs->ops.retire = retire_paused_capture_urb;
916                 return 0;
917         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
918                 subs->ops.retire = retire_capture_urb;
919                 return 0;
920         }
921
922         return -EINVAL;
923 }
924
925 int snd_usb_substream_prepare(struct snd_usb_substream *subs,
926                               struct snd_pcm_runtime *runtime)
927 {
928         /* clear urbs (to be sure) */
929         deactivate_urbs(subs, 0, 1);
930         wait_clear_urbs(subs);
931
932         /* for playback, submit the URBs now; otherwise, the first hwptr_done
933          * updates for all URBs would happen at the same time when starting */
934         if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
935                 subs->ops.prepare = prepare_nodata_playback_urb;
936                 return start_urbs(subs, runtime);
937         }
938
939         return 0;
940 }
941