2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 #include <linux/init.h>
18 #include <linux/slab.h>
19 #include <linux/ratelimit.h>
20 #include <linux/usb.h>
21 #include <linux/usb/audio.h>
22 #include <linux/usb/audio-v2.h>
24 #include <sound/core.h>
25 #include <sound/pcm.h>
26 #include <sound/pcm_params.h>
38 #define SUBSTREAM_FLAG_DATA_EP_STARTED 0
39 #define SUBSTREAM_FLAG_SYNC_EP_STARTED 1
41 /* return the estimated delay based on USB frame counters */
42 snd_pcm_uframes_t
snd_usb_pcm_delay(struct snd_usb_substream
*subs
,
45 int current_frame_number
;
49 if (!subs
->last_delay
)
50 return 0; /* short path */
52 current_frame_number
= usb_get_current_frame_number(subs
->dev
);
54 * HCD implementations use different widths, use lower 8 bits.
55 * The delay will be managed up to 256ms, which is more than
58 frame_diff
= (current_frame_number
- subs
->last_frame_number
) & 0xff;
60 /* Approximation based on number of samples per USB frame (ms),
61 some truncation for 44.1 but the estimate is good enough */
62 est_delay
= subs
->last_delay
- (frame_diff
* rate
/ 1000);
69 * return the current pcm pointer. just based on the hwptr_done value.
71 static snd_pcm_uframes_t
snd_usb_pcm_pointer(struct snd_pcm_substream
*substream
)
73 struct snd_usb_substream
*subs
;
74 unsigned int hwptr_done
;
76 subs
= (struct snd_usb_substream
*)substream
->runtime
->private_data
;
77 if (subs
->stream
->chip
->shutdown
)
78 return SNDRV_PCM_POS_XRUN
;
79 spin_lock(&subs
->lock
);
80 hwptr_done
= subs
->hwptr_done
;
81 if (substream
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
82 substream
->runtime
->delay
= snd_usb_pcm_delay(subs
,
83 substream
->runtime
->rate
);
84 spin_unlock(&subs
->lock
);
85 return hwptr_done
/ (substream
->runtime
->frame_bits
>> 3);
89 * find a matching audio format
91 static struct audioformat
*find_format(struct snd_usb_substream
*subs
)
94 struct audioformat
*found
= NULL
;
95 int cur_attr
= 0, attr
;
97 list_for_each(p
, &subs
->fmt_list
) {
98 struct audioformat
*fp
;
99 fp
= list_entry(p
, struct audioformat
, list
);
100 if (!(fp
->formats
& (1uLL << subs
->pcm_format
)))
102 if (fp
->channels
!= subs
->channels
)
104 if (subs
->cur_rate
< fp
->rate_min
||
105 subs
->cur_rate
> fp
->rate_max
)
107 if (! (fp
->rates
& SNDRV_PCM_RATE_CONTINUOUS
)) {
109 for (i
= 0; i
< fp
->nr_rates
; i
++)
110 if (fp
->rate_table
[i
] == subs
->cur_rate
)
112 if (i
>= fp
->nr_rates
)
115 attr
= fp
->ep_attr
& USB_ENDPOINT_SYNCTYPE
;
121 /* avoid async out and adaptive in if the other method
122 * supports the same format.
123 * this is a workaround for the case like
124 * M-audio audiophile USB.
126 if (attr
!= cur_attr
) {
127 if ((attr
== USB_ENDPOINT_SYNC_ASYNC
&&
128 subs
->direction
== SNDRV_PCM_STREAM_PLAYBACK
) ||
129 (attr
== USB_ENDPOINT_SYNC_ADAPTIVE
&&
130 subs
->direction
== SNDRV_PCM_STREAM_CAPTURE
))
132 if ((cur_attr
== USB_ENDPOINT_SYNC_ASYNC
&&
133 subs
->direction
== SNDRV_PCM_STREAM_PLAYBACK
) ||
134 (cur_attr
== USB_ENDPOINT_SYNC_ADAPTIVE
&&
135 subs
->direction
== SNDRV_PCM_STREAM_CAPTURE
)) {
141 /* find the format with the largest max. packet size */
142 if (fp
->maxpacksize
> found
->maxpacksize
) {
150 static int init_pitch_v1(struct snd_usb_audio
*chip
, int iface
,
151 struct usb_host_interface
*alts
,
152 struct audioformat
*fmt
)
154 struct usb_device
*dev
= chip
->dev
;
156 unsigned char data
[1];
159 ep
= get_endpoint(alts
, 0)->bEndpointAddress
;
162 if ((err
= snd_usb_ctl_msg(dev
, usb_sndctrlpipe(dev
, 0), UAC_SET_CUR
,
163 USB_TYPE_CLASS
|USB_RECIP_ENDPOINT
|USB_DIR_OUT
,
164 UAC_EP_CS_ATTR_PITCH_CONTROL
<< 8, ep
,
165 data
, sizeof(data
))) < 0) {
166 snd_printk(KERN_ERR
"%d:%d:%d: cannot set enable PITCH\n",
167 dev
->devnum
, iface
, ep
);
174 static int init_pitch_v2(struct snd_usb_audio
*chip
, int iface
,
175 struct usb_host_interface
*alts
,
176 struct audioformat
*fmt
)
178 struct usb_device
*dev
= chip
->dev
;
179 unsigned char data
[1];
183 if ((err
= snd_usb_ctl_msg(dev
, usb_sndctrlpipe(dev
, 0), UAC2_CS_CUR
,
184 USB_TYPE_CLASS
| USB_RECIP_ENDPOINT
| USB_DIR_OUT
,
185 UAC2_EP_CS_PITCH
<< 8, 0,
186 data
, sizeof(data
))) < 0) {
187 snd_printk(KERN_ERR
"%d:%d:%d: cannot set enable PITCH (v2)\n",
188 dev
->devnum
, iface
, fmt
->altsetting
);
196 * initialize the pitch control and sample rate
198 int snd_usb_init_pitch(struct snd_usb_audio
*chip
, int iface
,
199 struct usb_host_interface
*alts
,
200 struct audioformat
*fmt
)
202 struct usb_interface_descriptor
*altsd
= get_iface_desc(alts
);
204 /* if endpoint doesn't have pitch control, bail out */
205 if (!(fmt
->attributes
& UAC_EP_CS_ATTR_PITCH_CONTROL
))
208 switch (altsd
->bInterfaceProtocol
) {
211 return init_pitch_v1(chip
, iface
, alts
, fmt
);
214 return init_pitch_v2(chip
, iface
, alts
, fmt
);
218 static int start_endpoints(struct snd_usb_substream
*subs
, bool can_sleep
)
222 if (!subs
->data_endpoint
)
225 if (!test_and_set_bit(SUBSTREAM_FLAG_DATA_EP_STARTED
, &subs
->flags
)) {
226 struct snd_usb_endpoint
*ep
= subs
->data_endpoint
;
228 snd_printdd(KERN_DEBUG
"Starting data EP @%p\n", ep
);
230 ep
->data_subs
= subs
;
231 err
= snd_usb_endpoint_start(ep
, can_sleep
);
233 clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED
, &subs
->flags
);
238 if (subs
->sync_endpoint
&&
239 !test_and_set_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED
, &subs
->flags
)) {
240 struct snd_usb_endpoint
*ep
= subs
->sync_endpoint
;
242 if (subs
->data_endpoint
->iface
!= subs
->sync_endpoint
->iface
||
243 subs
->data_endpoint
->alt_idx
!= subs
->sync_endpoint
->alt_idx
) {
244 err
= usb_set_interface(subs
->dev
,
245 subs
->sync_endpoint
->iface
,
246 subs
->sync_endpoint
->alt_idx
);
249 "%d:%d:%d: cannot set interface (%d)\n",
251 subs
->sync_endpoint
->iface
,
252 subs
->sync_endpoint
->alt_idx
, err
);
257 snd_printdd(KERN_DEBUG
"Starting sync EP @%p\n", ep
);
259 ep
->sync_slave
= subs
->data_endpoint
;
260 err
= snd_usb_endpoint_start(ep
, can_sleep
);
262 clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED
, &subs
->flags
);
270 static void stop_endpoints(struct snd_usb_substream
*subs
, bool wait
)
272 if (test_and_clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED
, &subs
->flags
))
273 snd_usb_endpoint_stop(subs
->sync_endpoint
);
275 if (test_and_clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED
, &subs
->flags
))
276 snd_usb_endpoint_stop(subs
->data_endpoint
);
279 snd_usb_endpoint_sync_pending_stop(subs
->sync_endpoint
);
280 snd_usb_endpoint_sync_pending_stop(subs
->data_endpoint
);
284 static int deactivate_endpoints(struct snd_usb_substream
*subs
)
288 reta
= snd_usb_endpoint_deactivate(subs
->sync_endpoint
);
289 retb
= snd_usb_endpoint_deactivate(subs
->data_endpoint
);
301 * find a matching format and set up the interface
303 static int set_format(struct snd_usb_substream
*subs
, struct audioformat
*fmt
)
305 struct usb_device
*dev
= subs
->dev
;
306 struct usb_host_interface
*alts
;
307 struct usb_interface_descriptor
*altsd
;
308 struct usb_interface
*iface
;
309 unsigned int ep
, attr
;
310 int is_playback
= subs
->direction
== SNDRV_PCM_STREAM_PLAYBACK
;
311 int err
, implicit_fb
= 0;
313 iface
= usb_ifnum_to_if(dev
, fmt
->iface
);
316 alts
= &iface
->altsetting
[fmt
->altset_idx
];
317 altsd
= get_iface_desc(alts
);
318 if (WARN_ON(altsd
->bAlternateSetting
!= fmt
->altsetting
))
321 if (fmt
== subs
->cur_audiofmt
)
324 /* close the old interface */
325 if (subs
->interface
>= 0 && subs
->interface
!= fmt
->iface
) {
326 err
= usb_set_interface(subs
->dev
, subs
->interface
, 0);
328 snd_printk(KERN_ERR
"%d:%d:%d: return to setting 0 failed (%d)\n",
329 dev
->devnum
, fmt
->iface
, fmt
->altsetting
, err
);
332 subs
->interface
= -1;
333 subs
->altset_idx
= 0;
337 if (subs
->interface
!= fmt
->iface
||
338 subs
->altset_idx
!= fmt
->altset_idx
) {
339 err
= usb_set_interface(dev
, fmt
->iface
, fmt
->altsetting
);
341 snd_printk(KERN_ERR
"%d:%d:%d: usb_set_interface failed (%d)\n",
342 dev
->devnum
, fmt
->iface
, fmt
->altsetting
, err
);
345 snd_printdd(KERN_INFO
"setting usb interface %d:%d\n",
346 fmt
->iface
, fmt
->altsetting
);
347 subs
->interface
= fmt
->iface
;
348 subs
->altset_idx
= fmt
->altset_idx
;
351 subs
->data_endpoint
= snd_usb_add_endpoint(subs
->stream
->chip
,
352 alts
, fmt
->endpoint
, subs
->direction
,
353 SND_USB_ENDPOINT_TYPE_DATA
);
354 if (!subs
->data_endpoint
)
357 /* we need a sync pipe in async OUT or adaptive IN mode */
358 /* check the number of EP, since some devices have broken
359 * descriptors which fool us. if it has only one EP,
360 * assume it as adaptive-out or sync-in.
362 attr
= fmt
->ep_attr
& USB_ENDPOINT_SYNCTYPE
;
364 switch (subs
->stream
->chip
->usb_id
) {
365 case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
369 iface
= usb_ifnum_to_if(dev
, 3);
371 if (!iface
|| iface
->num_altsetting
== 0)
374 alts
= &iface
->altsetting
[1];
378 case USB_ID(0x0763, 0x2080): /* M-Audio FastTrack Ultra */
379 case USB_ID(0x0763, 0x2081):
383 iface
= usb_ifnum_to_if(dev
, 2);
385 if (!iface
|| iface
->num_altsetting
== 0)
388 alts
= &iface
->altsetting
[1];
393 if (((is_playback
&& attr
== USB_ENDPOINT_SYNC_ASYNC
) ||
394 (!is_playback
&& attr
== USB_ENDPOINT_SYNC_ADAPTIVE
)) &&
395 altsd
->bNumEndpoints
>= 2) {
396 /* check sync-pipe endpoint */
397 /* ... and check descriptor size before accessing bSynchAddress
398 because there is a version of the SB Audigy 2 NX firmware lacking
399 the audio fields in the endpoint descriptors */
400 if ((get_endpoint(alts
, 1)->bmAttributes
& USB_ENDPOINT_XFERTYPE_MASK
) != USB_ENDPOINT_XFER_ISOC
||
401 (get_endpoint(alts
, 1)->bLength
>= USB_DT_ENDPOINT_AUDIO_SIZE
&&
402 get_endpoint(alts
, 1)->bSynchAddress
!= 0 &&
404 snd_printk(KERN_ERR
"%d:%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
405 dev
->devnum
, fmt
->iface
, fmt
->altsetting
,
406 get_endpoint(alts
, 1)->bmAttributes
,
407 get_endpoint(alts
, 1)->bLength
,
408 get_endpoint(alts
, 1)->bSynchAddress
);
411 ep
= get_endpoint(alts
, 1)->bEndpointAddress
;
413 get_endpoint(alts
, 0)->bLength
>= USB_DT_ENDPOINT_AUDIO_SIZE
&&
414 (( is_playback
&& ep
!= (unsigned int)(get_endpoint(alts
, 0)->bSynchAddress
| USB_DIR_IN
)) ||
415 (!is_playback
&& ep
!= (unsigned int)(get_endpoint(alts
, 0)->bSynchAddress
& ~USB_DIR_IN
)))) {
416 snd_printk(KERN_ERR
"%d:%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
417 dev
->devnum
, fmt
->iface
, fmt
->altsetting
,
418 is_playback
, ep
, get_endpoint(alts
, 0)->bSynchAddress
);
422 implicit_fb
= (get_endpoint(alts
, 1)->bmAttributes
& USB_ENDPOINT_USAGE_MASK
)
423 == USB_ENDPOINT_USAGE_IMPLICIT_FB
;
426 subs
->sync_endpoint
= snd_usb_add_endpoint(subs
->stream
->chip
,
427 alts
, ep
, !subs
->direction
,
429 SND_USB_ENDPOINT_TYPE_DATA
:
430 SND_USB_ENDPOINT_TYPE_SYNC
);
431 if (!subs
->sync_endpoint
)
434 subs
->data_endpoint
->sync_master
= subs
->sync_endpoint
;
437 if ((err
= snd_usb_init_pitch(subs
->stream
->chip
, fmt
->iface
, alts
, fmt
)) < 0)
440 subs
->cur_audiofmt
= fmt
;
442 snd_usb_set_format_quirk(subs
, fmt
);
446 "setting done: format = %d, rate = %d..%d, channels = %d\n",
447 fmt
->format
, fmt
->rate_min
, fmt
->rate_max
, fmt
->channels
);
449 " datapipe = 0x%0x, syncpipe = 0x%0x\n",
450 subs
->datapipe
, subs
->syncpipe
);
457 * Return the score of matching two audioformats.
458 * Veto the audioformat if:
459 * - It has no channels for some reason.
460 * - Requested PCM format is not supported.
461 * - Requested sample rate is not supported.
463 static int match_endpoint_audioformats(struct audioformat
*fp
,
464 struct audioformat
*match
, int rate
,
465 snd_pcm_format_t pcm_format
)
470 if (fp
->channels
< 1) {
471 snd_printdd("%s: (fmt @%p) no channels\n", __func__
, fp
);
475 if (!(fp
->formats
& (1ULL << pcm_format
))) {
476 snd_printdd("%s: (fmt @%p) no match for format %d\n", __func__
,
481 for (i
= 0; i
< fp
->nr_rates
; i
++) {
482 if (fp
->rate_table
[i
] == rate
) {
488 snd_printdd("%s: (fmt @%p) no match for rate %d\n", __func__
,
493 if (fp
->channels
== match
->channels
)
496 snd_printdd("%s: (fmt @%p) score %d\n", __func__
, fp
, score
);
502 * Configure the sync ep using the rate and pcm format of the data ep.
504 static int configure_sync_endpoint(struct snd_usb_substream
*subs
)
507 struct audioformat
*fp
;
508 struct audioformat
*sync_fp
= NULL
;
510 int sync_period_bytes
= subs
->period_bytes
;
511 struct snd_usb_substream
*sync_subs
=
512 &subs
->stream
->substream
[subs
->direction
^ 1];
514 if (subs
->sync_endpoint
->type
!= SND_USB_ENDPOINT_TYPE_DATA
||
516 return snd_usb_endpoint_set_params(subs
->sync_endpoint
,
524 /* Try to find the best matching audioformat. */
525 list_for_each_entry(fp
, &sync_subs
->fmt_list
, list
) {
526 int score
= match_endpoint_audioformats(fp
, subs
->cur_audiofmt
,
527 subs
->cur_rate
, subs
->pcm_format
);
529 if (score
> cur_score
) {
535 if (unlikely(sync_fp
== NULL
)) {
536 snd_printk(KERN_ERR
"%s: no valid audioformat for sync ep %x found\n",
537 __func__
, sync_subs
->ep_num
);
542 * Recalculate the period bytes if channel number differ between
543 * data and sync ep audioformat.
545 if (sync_fp
->channels
!= subs
->channels
) {
546 sync_period_bytes
= (subs
->period_bytes
/ subs
->channels
) *
548 snd_printdd("%s: adjusted sync ep period bytes (%d -> %d)\n",
549 __func__
, subs
->period_bytes
, sync_period_bytes
);
552 ret
= snd_usb_endpoint_set_params(subs
->sync_endpoint
,
564 * configure endpoint params
566 * called during initial setup and upon resume
568 static int configure_endpoint(struct snd_usb_substream
*subs
)
573 stop_endpoints(subs
, true);
574 ret
= snd_usb_endpoint_set_params(subs
->data_endpoint
,
580 subs
->sync_endpoint
);
584 if (subs
->sync_endpoint
)
585 ret
= configure_sync_endpoint(subs
);
593 * allocate a buffer and set the given audio format.
595 * so far we use a physically linear buffer although packetize transfer
596 * doesn't need a continuous area.
597 * if sg buffer is supported on the later version of alsa, we'll follow
600 static int snd_usb_hw_params(struct snd_pcm_substream
*substream
,
601 struct snd_pcm_hw_params
*hw_params
)
603 struct snd_usb_substream
*subs
= substream
->runtime
->private_data
;
604 struct audioformat
*fmt
;
607 ret
= snd_pcm_lib_alloc_vmalloc_buffer(substream
,
608 params_buffer_bytes(hw_params
));
612 subs
->pcm_format
= params_format(hw_params
);
613 subs
->period_bytes
= params_period_bytes(hw_params
);
614 subs
->channels
= params_channels(hw_params
);
615 subs
->cur_rate
= params_rate(hw_params
);
617 fmt
= find_format(subs
);
619 snd_printd(KERN_DEBUG
"cannot set format: format = %#x, rate = %d, channels = %d\n",
620 subs
->pcm_format
, subs
->cur_rate
, subs
->channels
);
624 down_read(&subs
->stream
->chip
->shutdown_rwsem
);
625 if (subs
->stream
->chip
->shutdown
)
628 ret
= set_format(subs
, fmt
);
629 up_read(&subs
->stream
->chip
->shutdown_rwsem
);
633 subs
->interface
= fmt
->iface
;
634 subs
->altset_idx
= fmt
->altset_idx
;
635 subs
->need_setup_ep
= true;
643 * reset the audio format and release the buffer
645 static int snd_usb_hw_free(struct snd_pcm_substream
*substream
)
647 struct snd_usb_substream
*subs
= substream
->runtime
->private_data
;
649 subs
->cur_audiofmt
= NULL
;
651 subs
->period_bytes
= 0;
652 down_read(&subs
->stream
->chip
->shutdown_rwsem
);
653 if (!subs
->stream
->chip
->shutdown
) {
654 stop_endpoints(subs
, true);
655 deactivate_endpoints(subs
);
657 up_read(&subs
->stream
->chip
->shutdown_rwsem
);
658 return snd_pcm_lib_free_vmalloc_buffer(substream
);
664 * only a few subtle things...
666 static int snd_usb_pcm_prepare(struct snd_pcm_substream
*substream
)
668 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
669 struct snd_usb_substream
*subs
= runtime
->private_data
;
670 struct usb_host_interface
*alts
;
671 struct usb_interface
*iface
;
674 if (! subs
->cur_audiofmt
) {
675 snd_printk(KERN_ERR
"usbaudio: no format is specified!\n");
679 down_read(&subs
->stream
->chip
->shutdown_rwsem
);
680 if (subs
->stream
->chip
->shutdown
) {
684 if (snd_BUG_ON(!subs
->data_endpoint
)) {
689 snd_usb_endpoint_sync_pending_stop(subs
->sync_endpoint
);
690 snd_usb_endpoint_sync_pending_stop(subs
->data_endpoint
);
692 ret
= set_format(subs
, subs
->cur_audiofmt
);
696 iface
= usb_ifnum_to_if(subs
->dev
, subs
->cur_audiofmt
->iface
);
697 alts
= &iface
->altsetting
[subs
->cur_audiofmt
->altset_idx
];
698 ret
= snd_usb_init_sample_rate(subs
->stream
->chip
,
699 subs
->cur_audiofmt
->iface
,
706 if (subs
->need_setup_ep
) {
707 ret
= configure_endpoint(subs
);
710 subs
->need_setup_ep
= false;
713 /* some unit conversions in runtime */
714 subs
->data_endpoint
->maxframesize
=
715 bytes_to_frames(runtime
, subs
->data_endpoint
->maxpacksize
);
716 subs
->data_endpoint
->curframesize
=
717 bytes_to_frames(runtime
, subs
->data_endpoint
->curpacksize
);
719 /* reset the pointer */
720 subs
->hwptr_done
= 0;
721 subs
->transfer_done
= 0;
722 subs
->last_delay
= 0;
723 subs
->last_frame_number
= 0;
726 /* for playback, submit the URBs now; otherwise, the first hwptr_done
727 * updates for all URBs would happen at the same time when starting */
728 if (subs
->direction
== SNDRV_PCM_STREAM_PLAYBACK
)
729 ret
= start_endpoints(subs
, true);
732 up_read(&subs
->stream
->chip
->shutdown_rwsem
);
736 static struct snd_pcm_hardware snd_usb_hardware
=
738 .info
= SNDRV_PCM_INFO_MMAP
|
739 SNDRV_PCM_INFO_MMAP_VALID
|
740 SNDRV_PCM_INFO_BATCH
|
741 SNDRV_PCM_INFO_INTERLEAVED
|
742 SNDRV_PCM_INFO_BLOCK_TRANSFER
|
743 SNDRV_PCM_INFO_PAUSE
,
744 .buffer_bytes_max
= 1024 * 1024,
745 .period_bytes_min
= 64,
746 .period_bytes_max
= 512 * 1024,
751 static int hw_check_valid_format(struct snd_usb_substream
*subs
,
752 struct snd_pcm_hw_params
*params
,
753 struct audioformat
*fp
)
755 struct snd_interval
*it
= hw_param_interval(params
, SNDRV_PCM_HW_PARAM_RATE
);
756 struct snd_interval
*ct
= hw_param_interval(params
, SNDRV_PCM_HW_PARAM_CHANNELS
);
757 struct snd_mask
*fmts
= hw_param_mask(params
, SNDRV_PCM_HW_PARAM_FORMAT
);
758 struct snd_interval
*pt
= hw_param_interval(params
, SNDRV_PCM_HW_PARAM_PERIOD_TIME
);
759 struct snd_mask check_fmts
;
762 /* check the format */
763 snd_mask_none(&check_fmts
);
764 check_fmts
.bits
[0] = (u32
)fp
->formats
;
765 check_fmts
.bits
[1] = (u32
)(fp
->formats
>> 32);
766 snd_mask_intersect(&check_fmts
, fmts
);
767 if (snd_mask_empty(&check_fmts
)) {
768 hwc_debug(" > check: no supported format %d\n", fp
->format
);
771 /* check the channels */
772 if (fp
->channels
< ct
->min
|| fp
->channels
> ct
->max
) {
773 hwc_debug(" > check: no valid channels %d (%d/%d)\n", fp
->channels
, ct
->min
, ct
->max
);
776 /* check the rate is within the range */
777 if (fp
->rate_min
> it
->max
|| (fp
->rate_min
== it
->max
&& it
->openmax
)) {
778 hwc_debug(" > check: rate_min %d > max %d\n", fp
->rate_min
, it
->max
);
781 if (fp
->rate_max
< it
->min
|| (fp
->rate_max
== it
->min
&& it
->openmin
)) {
782 hwc_debug(" > check: rate_max %d < min %d\n", fp
->rate_max
, it
->min
);
785 /* check whether the period time is >= the data packet interval */
786 if (subs
->speed
!= USB_SPEED_FULL
) {
787 ptime
= 125 * (1 << fp
->datainterval
);
788 if (ptime
> pt
->max
|| (ptime
== pt
->max
&& pt
->openmax
)) {
789 hwc_debug(" > check: ptime %u > max %u\n", ptime
, pt
->max
);
796 static int hw_rule_rate(struct snd_pcm_hw_params
*params
,
797 struct snd_pcm_hw_rule
*rule
)
799 struct snd_usb_substream
*subs
= rule
->private;
801 struct snd_interval
*it
= hw_param_interval(params
, SNDRV_PCM_HW_PARAM_RATE
);
802 unsigned int rmin
, rmax
;
805 hwc_debug("hw_rule_rate: (%d,%d)\n", it
->min
, it
->max
);
808 list_for_each(p
, &subs
->fmt_list
) {
809 struct audioformat
*fp
;
810 fp
= list_entry(p
, struct audioformat
, list
);
811 if (!hw_check_valid_format(subs
, params
, fp
))
814 if (rmin
> fp
->rate_min
)
816 if (rmax
< fp
->rate_max
)
825 hwc_debug(" --> get empty\n");
831 if (it
->min
< rmin
) {
836 if (it
->max
> rmax
) {
841 if (snd_interval_checkempty(it
)) {
845 hwc_debug(" --> (%d, %d) (changed = %d)\n", it
->min
, it
->max
, changed
);
850 static int hw_rule_channels(struct snd_pcm_hw_params
*params
,
851 struct snd_pcm_hw_rule
*rule
)
853 struct snd_usb_substream
*subs
= rule
->private;
855 struct snd_interval
*it
= hw_param_interval(params
, SNDRV_PCM_HW_PARAM_CHANNELS
);
856 unsigned int rmin
, rmax
;
859 hwc_debug("hw_rule_channels: (%d,%d)\n", it
->min
, it
->max
);
862 list_for_each(p
, &subs
->fmt_list
) {
863 struct audioformat
*fp
;
864 fp
= list_entry(p
, struct audioformat
, list
);
865 if (!hw_check_valid_format(subs
, params
, fp
))
868 if (rmin
> fp
->channels
)
870 if (rmax
< fp
->channels
)
879 hwc_debug(" --> get empty\n");
885 if (it
->min
< rmin
) {
890 if (it
->max
> rmax
) {
895 if (snd_interval_checkempty(it
)) {
899 hwc_debug(" --> (%d, %d) (changed = %d)\n", it
->min
, it
->max
, changed
);
903 static int hw_rule_format(struct snd_pcm_hw_params
*params
,
904 struct snd_pcm_hw_rule
*rule
)
906 struct snd_usb_substream
*subs
= rule
->private;
908 struct snd_mask
*fmt
= hw_param_mask(params
, SNDRV_PCM_HW_PARAM_FORMAT
);
913 hwc_debug("hw_rule_format: %x:%x\n", fmt
->bits
[0], fmt
->bits
[1]);
915 list_for_each(p
, &subs
->fmt_list
) {
916 struct audioformat
*fp
;
917 fp
= list_entry(p
, struct audioformat
, list
);
918 if (!hw_check_valid_format(subs
, params
, fp
))
920 fbits
|= fp
->formats
;
923 oldbits
[0] = fmt
->bits
[0];
924 oldbits
[1] = fmt
->bits
[1];
925 fmt
->bits
[0] &= (u32
)fbits
;
926 fmt
->bits
[1] &= (u32
)(fbits
>> 32);
927 if (!fmt
->bits
[0] && !fmt
->bits
[1]) {
928 hwc_debug(" --> get empty\n");
931 changed
= (oldbits
[0] != fmt
->bits
[0] || oldbits
[1] != fmt
->bits
[1]);
932 hwc_debug(" --> %x:%x (changed = %d)\n", fmt
->bits
[0], fmt
->bits
[1], changed
);
936 static int hw_rule_period_time(struct snd_pcm_hw_params
*params
,
937 struct snd_pcm_hw_rule
*rule
)
939 struct snd_usb_substream
*subs
= rule
->private;
940 struct audioformat
*fp
;
941 struct snd_interval
*it
;
942 unsigned char min_datainterval
;
946 it
= hw_param_interval(params
, SNDRV_PCM_HW_PARAM_PERIOD_TIME
);
947 hwc_debug("hw_rule_period_time: (%u,%u)\n", it
->min
, it
->max
);
948 min_datainterval
= 0xff;
949 list_for_each_entry(fp
, &subs
->fmt_list
, list
) {
950 if (!hw_check_valid_format(subs
, params
, fp
))
952 min_datainterval
= min(min_datainterval
, fp
->datainterval
);
954 if (min_datainterval
== 0xff) {
955 hwc_debug(" --> get empty\n");
959 pmin
= 125 * (1 << min_datainterval
);
961 if (it
->min
< pmin
) {
966 if (snd_interval_checkempty(it
)) {
970 hwc_debug(" --> (%u,%u) (changed = %d)\n", it
->min
, it
->max
, changed
);
975 * If the device supports unusual bit rates, does the request meet these?
977 static int snd_usb_pcm_check_knot(struct snd_pcm_runtime
*runtime
,
978 struct snd_usb_substream
*subs
)
980 struct audioformat
*fp
;
982 int count
= 0, needs_knot
= 0;
985 kfree(subs
->rate_list
.list
);
986 subs
->rate_list
.list
= NULL
;
988 list_for_each_entry(fp
, &subs
->fmt_list
, list
) {
989 if (fp
->rates
& SNDRV_PCM_RATE_CONTINUOUS
)
991 count
+= fp
->nr_rates
;
992 if (fp
->rates
& SNDRV_PCM_RATE_KNOT
)
998 subs
->rate_list
.list
= rate_list
=
999 kmalloc(sizeof(int) * count
, GFP_KERNEL
);
1000 if (!subs
->rate_list
.list
)
1002 subs
->rate_list
.count
= count
;
1003 subs
->rate_list
.mask
= 0;
1005 list_for_each_entry(fp
, &subs
->fmt_list
, list
) {
1007 for (i
= 0; i
< fp
->nr_rates
; i
++)
1008 rate_list
[count
++] = fp
->rate_table
[i
];
1010 err
= snd_pcm_hw_constraint_list(runtime
, 0, SNDRV_PCM_HW_PARAM_RATE
,
1020 * set up the runtime hardware information.
1023 static int setup_hw_info(struct snd_pcm_runtime
*runtime
, struct snd_usb_substream
*subs
)
1025 struct list_head
*p
;
1026 unsigned int pt
, ptmin
;
1027 int param_period_time_if_needed
;
1030 runtime
->hw
.formats
= subs
->formats
;
1032 runtime
->hw
.rate_min
= 0x7fffffff;
1033 runtime
->hw
.rate_max
= 0;
1034 runtime
->hw
.channels_min
= 256;
1035 runtime
->hw
.channels_max
= 0;
1036 runtime
->hw
.rates
= 0;
1038 /* check min/max rates and channels */
1039 list_for_each(p
, &subs
->fmt_list
) {
1040 struct audioformat
*fp
;
1041 fp
= list_entry(p
, struct audioformat
, list
);
1042 runtime
->hw
.rates
|= fp
->rates
;
1043 if (runtime
->hw
.rate_min
> fp
->rate_min
)
1044 runtime
->hw
.rate_min
= fp
->rate_min
;
1045 if (runtime
->hw
.rate_max
< fp
->rate_max
)
1046 runtime
->hw
.rate_max
= fp
->rate_max
;
1047 if (runtime
->hw
.channels_min
> fp
->channels
)
1048 runtime
->hw
.channels_min
= fp
->channels
;
1049 if (runtime
->hw
.channels_max
< fp
->channels
)
1050 runtime
->hw
.channels_max
= fp
->channels
;
1051 if (fp
->fmt_type
== UAC_FORMAT_TYPE_II
&& fp
->frame_size
> 0) {
1052 /* FIXME: there might be more than one audio formats... */
1053 runtime
->hw
.period_bytes_min
= runtime
->hw
.period_bytes_max
=
1056 pt
= 125 * (1 << fp
->datainterval
);
1057 ptmin
= min(ptmin
, pt
);
1059 err
= snd_usb_autoresume(subs
->stream
->chip
);
1063 param_period_time_if_needed
= SNDRV_PCM_HW_PARAM_PERIOD_TIME
;
1064 if (subs
->speed
== USB_SPEED_FULL
)
1065 /* full speed devices have fixed data packet interval */
1068 /* if period time doesn't go below 1 ms, no rules needed */
1069 param_period_time_if_needed
= -1;
1070 snd_pcm_hw_constraint_minmax(runtime
, SNDRV_PCM_HW_PARAM_PERIOD_TIME
,
1073 if ((err
= snd_pcm_hw_rule_add(runtime
, 0, SNDRV_PCM_HW_PARAM_RATE
,
1075 SNDRV_PCM_HW_PARAM_FORMAT
,
1076 SNDRV_PCM_HW_PARAM_CHANNELS
,
1077 param_period_time_if_needed
,
1080 if ((err
= snd_pcm_hw_rule_add(runtime
, 0, SNDRV_PCM_HW_PARAM_CHANNELS
,
1081 hw_rule_channels
, subs
,
1082 SNDRV_PCM_HW_PARAM_FORMAT
,
1083 SNDRV_PCM_HW_PARAM_RATE
,
1084 param_period_time_if_needed
,
1087 if ((err
= snd_pcm_hw_rule_add(runtime
, 0, SNDRV_PCM_HW_PARAM_FORMAT
,
1088 hw_rule_format
, subs
,
1089 SNDRV_PCM_HW_PARAM_RATE
,
1090 SNDRV_PCM_HW_PARAM_CHANNELS
,
1091 param_period_time_if_needed
,
1094 if (param_period_time_if_needed
>= 0) {
1095 err
= snd_pcm_hw_rule_add(runtime
, 0,
1096 SNDRV_PCM_HW_PARAM_PERIOD_TIME
,
1097 hw_rule_period_time
, subs
,
1098 SNDRV_PCM_HW_PARAM_FORMAT
,
1099 SNDRV_PCM_HW_PARAM_CHANNELS
,
1100 SNDRV_PCM_HW_PARAM_RATE
,
1105 if ((err
= snd_usb_pcm_check_knot(runtime
, subs
)) < 0)
1110 snd_usb_autosuspend(subs
->stream
->chip
);
1114 static int snd_usb_pcm_open(struct snd_pcm_substream
*substream
, int direction
)
1116 struct snd_usb_stream
*as
= snd_pcm_substream_chip(substream
);
1117 struct snd_pcm_runtime
*runtime
= substream
->runtime
;
1118 struct snd_usb_substream
*subs
= &as
->substream
[direction
];
1120 subs
->interface
= -1;
1121 subs
->altset_idx
= 0;
1122 runtime
->hw
= snd_usb_hardware
;
1123 runtime
->private_data
= subs
;
1124 subs
->pcm_substream
= substream
;
1125 /* runtime PM is also done there */
1126 return setup_hw_info(runtime
, subs
);
1129 static int snd_usb_pcm_close(struct snd_pcm_substream
*substream
, int direction
)
1131 struct snd_usb_stream
*as
= snd_pcm_substream_chip(substream
);
1132 struct snd_usb_substream
*subs
= &as
->substream
[direction
];
1134 stop_endpoints(subs
, true);
1136 if (!as
->chip
->shutdown
&& subs
->interface
>= 0) {
1137 usb_set_interface(subs
->dev
, subs
->interface
, 0);
1138 subs
->interface
= -1;
1141 subs
->pcm_substream
= NULL
;
1142 snd_usb_autosuspend(subs
->stream
->chip
);
1147 /* Since a URB can handle only a single linear buffer, we must use double
1148 * buffering when the data to be transferred overflows the buffer boundary.
1149 * To avoid inconsistencies when updating hwptr_done, we use double buffering
1152 static void retire_capture_urb(struct snd_usb_substream
*subs
,
1155 struct snd_pcm_runtime
*runtime
= subs
->pcm_substream
->runtime
;
1156 unsigned int stride
, frames
, bytes
, oldptr
;
1157 int i
, period_elapsed
= 0;
1158 unsigned long flags
;
1161 stride
= runtime
->frame_bits
>> 3;
1163 for (i
= 0; i
< urb
->number_of_packets
; i
++) {
1164 cp
= (unsigned char *)urb
->transfer_buffer
+ urb
->iso_frame_desc
[i
].offset
;
1165 if (urb
->iso_frame_desc
[i
].status
&& printk_ratelimit()) {
1166 snd_printdd(KERN_ERR
"frame %d active: %d\n", i
, urb
->iso_frame_desc
[i
].status
);
1169 bytes
= urb
->iso_frame_desc
[i
].actual_length
;
1170 frames
= bytes
/ stride
;
1171 if (!subs
->txfr_quirk
)
1172 bytes
= frames
* stride
;
1173 if (bytes
% (runtime
->sample_bits
>> 3) != 0) {
1174 #ifdef CONFIG_SND_DEBUG_VERBOSE
1175 int oldbytes
= bytes
;
1177 bytes
= frames
* stride
;
1178 snd_printdd(KERN_ERR
"Corrected urb data len. %d->%d\n",
1181 /* update the current pointer */
1182 spin_lock_irqsave(&subs
->lock
, flags
);
1183 oldptr
= subs
->hwptr_done
;
1184 subs
->hwptr_done
+= bytes
;
1185 if (subs
->hwptr_done
>= runtime
->buffer_size
* stride
)
1186 subs
->hwptr_done
-= runtime
->buffer_size
* stride
;
1187 frames
= (bytes
+ (oldptr
% stride
)) / stride
;
1188 subs
->transfer_done
+= frames
;
1189 if (subs
->transfer_done
>= runtime
->period_size
) {
1190 subs
->transfer_done
-= runtime
->period_size
;
1193 spin_unlock_irqrestore(&subs
->lock
, flags
);
1194 /* copy a data chunk */
1195 if (oldptr
+ bytes
> runtime
->buffer_size
* stride
) {
1196 unsigned int bytes1
=
1197 runtime
->buffer_size
* stride
- oldptr
;
1198 memcpy(runtime
->dma_area
+ oldptr
, cp
, bytes1
);
1199 memcpy(runtime
->dma_area
, cp
+ bytes1
, bytes
- bytes1
);
1201 memcpy(runtime
->dma_area
+ oldptr
, cp
, bytes
);
1206 snd_pcm_period_elapsed(subs
->pcm_substream
);
1209 static void prepare_playback_urb(struct snd_usb_substream
*subs
,
1212 struct snd_pcm_runtime
*runtime
= subs
->pcm_substream
->runtime
;
1213 struct snd_usb_endpoint
*ep
= subs
->data_endpoint
;
1214 struct snd_urb_ctx
*ctx
= urb
->context
;
1215 unsigned int counts
, frames
, bytes
;
1216 int i
, stride
, period_elapsed
= 0;
1217 unsigned long flags
;
1219 stride
= runtime
->frame_bits
>> 3;
1222 urb
->number_of_packets
= 0;
1223 spin_lock_irqsave(&subs
->lock
, flags
);
1224 for (i
= 0; i
< ctx
->packets
; i
++) {
1225 if (ctx
->packet_size
[i
])
1226 counts
= ctx
->packet_size
[i
];
1228 counts
= snd_usb_endpoint_next_packet_size(ep
);
1230 /* set up descriptor */
1231 urb
->iso_frame_desc
[i
].offset
= frames
* stride
;
1232 urb
->iso_frame_desc
[i
].length
= counts
* stride
;
1234 urb
->number_of_packets
++;
1235 subs
->transfer_done
+= counts
;
1236 if (subs
->transfer_done
>= runtime
->period_size
) {
1237 subs
->transfer_done
-= runtime
->period_size
;
1239 if (subs
->fmt_type
== UAC_FORMAT_TYPE_II
) {
1240 if (subs
->transfer_done
> 0) {
1241 /* FIXME: fill-max mode is not
1243 frames
-= subs
->transfer_done
;
1244 counts
-= subs
->transfer_done
;
1245 urb
->iso_frame_desc
[i
].length
=
1247 subs
->transfer_done
= 0;
1250 if (i
< ctx
->packets
) {
1251 /* add a transfer delimiter */
1252 urb
->iso_frame_desc
[i
].offset
=
1254 urb
->iso_frame_desc
[i
].length
= 0;
1255 urb
->number_of_packets
++;
1260 if (period_elapsed
&&
1261 !snd_usb_endpoint_implict_feedback_sink(subs
->data_endpoint
)) /* finish at the period boundary */
1264 bytes
= frames
* stride
;
1265 if (subs
->hwptr_done
+ bytes
> runtime
->buffer_size
* stride
) {
1266 /* err, the transferred area goes over buffer boundary. */
1267 unsigned int bytes1
=
1268 runtime
->buffer_size
* stride
- subs
->hwptr_done
;
1269 memcpy(urb
->transfer_buffer
,
1270 runtime
->dma_area
+ subs
->hwptr_done
, bytes1
);
1271 memcpy(urb
->transfer_buffer
+ bytes1
,
1272 runtime
->dma_area
, bytes
- bytes1
);
1274 memcpy(urb
->transfer_buffer
,
1275 runtime
->dma_area
+ subs
->hwptr_done
, bytes
);
1277 subs
->hwptr_done
+= bytes
;
1278 if (subs
->hwptr_done
>= runtime
->buffer_size
* stride
)
1279 subs
->hwptr_done
-= runtime
->buffer_size
* stride
;
1281 /* update delay with exact number of samples queued */
1282 runtime
->delay
= subs
->last_delay
;
1283 runtime
->delay
+= frames
;
1284 subs
->last_delay
= runtime
->delay
;
1286 /* realign last_frame_number */
1287 subs
->last_frame_number
= usb_get_current_frame_number(subs
->dev
);
1288 subs
->last_frame_number
&= 0xFF; /* keep 8 LSBs */
1290 spin_unlock_irqrestore(&subs
->lock
, flags
);
1291 urb
->transfer_buffer_length
= bytes
;
1293 snd_pcm_period_elapsed(subs
->pcm_substream
);
1297 * process after playback data complete
1298 * - decrease the delay count again
1300 static void retire_playback_urb(struct snd_usb_substream
*subs
,
1303 unsigned long flags
;
1304 struct snd_pcm_runtime
*runtime
= subs
->pcm_substream
->runtime
;
1305 int stride
= runtime
->frame_bits
>> 3;
1306 int processed
= urb
->transfer_buffer_length
/ stride
;
1309 /* ignore the delay accounting when procssed=0 is given, i.e.
1310 * silent payloads are procssed before handling the actual data
1315 spin_lock_irqsave(&subs
->lock
, flags
);
1316 if (!subs
->last_delay
)
1317 goto out
; /* short path */
1319 est_delay
= snd_usb_pcm_delay(subs
, runtime
->rate
);
1320 /* update delay with exact number of samples played */
1321 if (processed
> subs
->last_delay
)
1322 subs
->last_delay
= 0;
1324 subs
->last_delay
-= processed
;
1325 runtime
->delay
= subs
->last_delay
;
1328 * Report when delay estimate is off by more than 2ms.
1329 * The error should be lower than 2ms since the estimate relies
1330 * on two reads of a counter updated every ms.
1332 if (abs(est_delay
- subs
->last_delay
) * 1000 > runtime
->rate
* 2)
1333 snd_printk(KERN_DEBUG
"delay: estimated %d, actual %d\n",
1334 est_delay
, subs
->last_delay
);
1336 if (!subs
->running
) {
1337 /* update last_frame_number for delay counting here since
1338 * prepare_playback_urb won't be called during pause
1340 subs
->last_frame_number
=
1341 usb_get_current_frame_number(subs
->dev
) & 0xff;
1345 spin_unlock_irqrestore(&subs
->lock
, flags
);
1348 static int snd_usb_playback_open(struct snd_pcm_substream
*substream
)
1350 return snd_usb_pcm_open(substream
, SNDRV_PCM_STREAM_PLAYBACK
);
1353 static int snd_usb_playback_close(struct snd_pcm_substream
*substream
)
1355 return snd_usb_pcm_close(substream
, SNDRV_PCM_STREAM_PLAYBACK
);
1358 static int snd_usb_capture_open(struct snd_pcm_substream
*substream
)
1360 return snd_usb_pcm_open(substream
, SNDRV_PCM_STREAM_CAPTURE
);
1363 static int snd_usb_capture_close(struct snd_pcm_substream
*substream
)
1365 return snd_usb_pcm_close(substream
, SNDRV_PCM_STREAM_CAPTURE
);
1368 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream
*substream
,
1371 struct snd_usb_substream
*subs
= substream
->runtime
->private_data
;
1374 case SNDRV_PCM_TRIGGER_START
:
1375 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE
:
1376 subs
->data_endpoint
->prepare_data_urb
= prepare_playback_urb
;
1377 subs
->data_endpoint
->retire_data_urb
= retire_playback_urb
;
1380 case SNDRV_PCM_TRIGGER_STOP
:
1381 stop_endpoints(subs
, false);
1384 case SNDRV_PCM_TRIGGER_PAUSE_PUSH
:
1385 subs
->data_endpoint
->prepare_data_urb
= NULL
;
1386 /* keep retire_data_urb for delay calculation */
1387 subs
->data_endpoint
->retire_data_urb
= retire_playback_urb
;
1395 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream
*substream
,
1399 struct snd_usb_substream
*subs
= substream
->runtime
->private_data
;
1402 case SNDRV_PCM_TRIGGER_START
:
1403 err
= start_endpoints(subs
, false);
1407 subs
->data_endpoint
->retire_data_urb
= retire_capture_urb
;
1410 case SNDRV_PCM_TRIGGER_STOP
:
1411 stop_endpoints(subs
, false);
1414 case SNDRV_PCM_TRIGGER_PAUSE_PUSH
:
1415 subs
->data_endpoint
->retire_data_urb
= NULL
;
1418 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE
:
1419 subs
->data_endpoint
->retire_data_urb
= retire_capture_urb
;
1427 static struct snd_pcm_ops snd_usb_playback_ops
= {
1428 .open
= snd_usb_playback_open
,
1429 .close
= snd_usb_playback_close
,
1430 .ioctl
= snd_pcm_lib_ioctl
,
1431 .hw_params
= snd_usb_hw_params
,
1432 .hw_free
= snd_usb_hw_free
,
1433 .prepare
= snd_usb_pcm_prepare
,
1434 .trigger
= snd_usb_substream_playback_trigger
,
1435 .pointer
= snd_usb_pcm_pointer
,
1436 .page
= snd_pcm_lib_get_vmalloc_page
,
1437 .mmap
= snd_pcm_lib_mmap_vmalloc
,
1440 static struct snd_pcm_ops snd_usb_capture_ops
= {
1441 .open
= snd_usb_capture_open
,
1442 .close
= snd_usb_capture_close
,
1443 .ioctl
= snd_pcm_lib_ioctl
,
1444 .hw_params
= snd_usb_hw_params
,
1445 .hw_free
= snd_usb_hw_free
,
1446 .prepare
= snd_usb_pcm_prepare
,
1447 .trigger
= snd_usb_substream_capture_trigger
,
1448 .pointer
= snd_usb_pcm_pointer
,
1449 .page
= snd_pcm_lib_get_vmalloc_page
,
1450 .mmap
= snd_pcm_lib_mmap_vmalloc
,
1453 void snd_usb_set_pcm_ops(struct snd_pcm
*pcm
, int stream
)
1455 snd_pcm_set_ops(pcm
, stream
,
1456 stream
== SNDRV_PCM_STREAM_PLAYBACK
?
1457 &snd_usb_playback_ops
: &snd_usb_capture_ops
);