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
18 #include <linux/gfp.h>
19 #include <linux/init.h>
20 #include <linux/ratelimit.h>
21 #include <linux/usb.h>
22 #include <linux/usb/audio.h>
23 #include <linux/slab.h>
25 #include <sound/core.h>
26 #include <sound/pcm.h>
27 #include <sound/pcm_params.h>
36 #define EP_FLAG_RUNNING 1
37 #define EP_FLAG_STOPPING 2
40 * snd_usb_endpoint is a model that abstracts everything related to an
41 * USB endpoint and its streaming.
43 * There are functions to activate and deactivate the streaming URBs and
44 * optional callbacks to let the pcm logic handle the actual content of the
45 * packets for playback and record. Thus, the bus streaming and the audio
46 * handlers are fully decoupled.
48 * There are two different types of endpoints in audio applications.
50 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both
51 * inbound and outbound traffic.
53 * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and
54 * expect the payload to carry Q10.14 / Q16.16 formatted sync information
57 * Each endpoint has to be configured prior to being used by calling
58 * snd_usb_endpoint_set_params().
60 * The model incorporates a reference counting, so that multiple users
61 * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and
62 * only the first user will effectively start the URBs, and only the last
63 * one to stop it will tear the URBs down again.
67 * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
68 * this will overflow at approx 524 kHz
70 static inline unsigned get_usb_full_speed_rate(unsigned int rate
)
72 return ((rate
<< 13) + 62) / 125;
76 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
77 * this will overflow at approx 4 MHz
79 static inline unsigned get_usb_high_speed_rate(unsigned int rate
)
81 return ((rate
<< 10) + 62) / 125;
87 static void release_urb_ctx(struct snd_urb_ctx
*u
)
90 usb_free_coherent(u
->ep
->chip
->dev
, u
->buffer_size
,
91 u
->urb
->transfer_buffer
,
92 u
->urb
->transfer_dma
);
97 static const char *usb_error_string(int err
)
103 return "endpoint not enabled";
105 return "endpoint stalled";
107 return "not enough bandwidth";
109 return "device disabled";
111 return "device suspended";
116 return "internal error";
118 return "unknown error";
123 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type
125 * @ep: The snd_usb_endpoint
127 * Determine whether an endpoint is driven by an implicit feedback
128 * data endpoint source.
130 int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint
*ep
)
132 return ep
->sync_master
&&
133 ep
->sync_master
->type
== SND_USB_ENDPOINT_TYPE_DATA
&&
134 ep
->type
== SND_USB_ENDPOINT_TYPE_DATA
&&
135 usb_pipeout(ep
->pipe
);
139 * For streaming based on information derived from sync endpoints,
140 * prepare_outbound_urb_sizes() will call next_packet_size() to
141 * determine the number of samples to be sent in the next packet.
143 * For implicit feedback, next_packet_size() is unused.
145 int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint
*ep
)
151 return ep
->maxframesize
;
153 spin_lock_irqsave(&ep
->lock
, flags
);
154 ep
->phase
= (ep
->phase
& 0xffff)
155 + (ep
->freqm
<< ep
->datainterval
);
156 ret
= min(ep
->phase
>> 16, ep
->maxframesize
);
157 spin_unlock_irqrestore(&ep
->lock
, flags
);
162 static void retire_outbound_urb(struct snd_usb_endpoint
*ep
,
163 struct snd_urb_ctx
*urb_ctx
)
165 if (ep
->retire_data_urb
)
166 ep
->retire_data_urb(ep
->data_subs
, urb_ctx
->urb
);
169 static void retire_inbound_urb(struct snd_usb_endpoint
*ep
,
170 struct snd_urb_ctx
*urb_ctx
)
172 struct urb
*urb
= urb_ctx
->urb
;
174 if (unlikely(ep
->skip_packets
> 0)) {
180 snd_usb_handle_sync_urb(ep
->sync_slave
, ep
, urb
);
182 if (ep
->retire_data_urb
)
183 ep
->retire_data_urb(ep
->data_subs
, urb
);
187 * Prepare a PLAYBACK urb for submission to the bus.
189 static void prepare_outbound_urb(struct snd_usb_endpoint
*ep
,
190 struct snd_urb_ctx
*ctx
)
193 struct urb
*urb
= ctx
->urb
;
194 unsigned char *cp
= urb
->transfer_buffer
;
196 urb
->dev
= ep
->chip
->dev
; /* we need to set this at each time */
199 case SND_USB_ENDPOINT_TYPE_DATA
:
200 if (ep
->prepare_data_urb
) {
201 ep
->prepare_data_urb(ep
->data_subs
, urb
);
203 /* no data provider, so send silence */
204 unsigned int offs
= 0;
205 for (i
= 0; i
< ctx
->packets
; ++i
) {
208 if (ctx
->packet_size
[i
])
209 counts
= ctx
->packet_size
[i
];
211 counts
= snd_usb_endpoint_next_packet_size(ep
);
213 urb
->iso_frame_desc
[i
].offset
= offs
* ep
->stride
;
214 urb
->iso_frame_desc
[i
].length
= counts
* ep
->stride
;
218 urb
->number_of_packets
= ctx
->packets
;
219 urb
->transfer_buffer_length
= offs
* ep
->stride
;
220 memset(urb
->transfer_buffer
, ep
->silence_value
,
225 case SND_USB_ENDPOINT_TYPE_SYNC
:
226 if (snd_usb_get_speed(ep
->chip
->dev
) >= USB_SPEED_HIGH
) {
228 * fill the length and offset of each urb descriptor.
229 * the fixed 12.13 frequency is passed as 16.16 through the pipe.
231 urb
->iso_frame_desc
[0].length
= 4;
232 urb
->iso_frame_desc
[0].offset
= 0;
234 cp
[1] = ep
->freqn
>> 8;
235 cp
[2] = ep
->freqn
>> 16;
236 cp
[3] = ep
->freqn
>> 24;
239 * fill the length and offset of each urb descriptor.
240 * the fixed 10.14 frequency is passed through the pipe.
242 urb
->iso_frame_desc
[0].length
= 3;
243 urb
->iso_frame_desc
[0].offset
= 0;
244 cp
[0] = ep
->freqn
>> 2;
245 cp
[1] = ep
->freqn
>> 10;
246 cp
[2] = ep
->freqn
>> 18;
254 * Prepare a CAPTURE or SYNC urb for submission to the bus.
256 static inline void prepare_inbound_urb(struct snd_usb_endpoint
*ep
,
257 struct snd_urb_ctx
*urb_ctx
)
260 struct urb
*urb
= urb_ctx
->urb
;
262 urb
->dev
= ep
->chip
->dev
; /* we need to set this at each time */
265 case SND_USB_ENDPOINT_TYPE_DATA
:
267 for (i
= 0; i
< urb_ctx
->packets
; i
++) {
268 urb
->iso_frame_desc
[i
].offset
= offs
;
269 urb
->iso_frame_desc
[i
].length
= ep
->curpacksize
;
270 offs
+= ep
->curpacksize
;
273 urb
->transfer_buffer_length
= offs
;
274 urb
->number_of_packets
= urb_ctx
->packets
;
277 case SND_USB_ENDPOINT_TYPE_SYNC
:
278 urb
->iso_frame_desc
[0].length
= min(4u, ep
->syncmaxsize
);
279 urb
->iso_frame_desc
[0].offset
= 0;
285 * Send output urbs that have been prepared previously. URBs are dequeued
286 * from ep->ready_playback_urbs and in case there there aren't any available
287 * or there are no packets that have been prepared, this function does
290 * The reason why the functionality of sending and preparing URBs is separated
291 * is that host controllers don't guarantee the order in which they return
292 * inbound and outbound packets to their submitters.
294 * This function is only used for implicit feedback endpoints. For endpoints
295 * driven by dedicated sync endpoints, URBs are immediately re-submitted
296 * from their completion handler.
298 static void queue_pending_output_urbs(struct snd_usb_endpoint
*ep
)
300 while (test_bit(EP_FLAG_RUNNING
, &ep
->flags
)) {
303 struct snd_usb_packet_info
*uninitialized_var(packet
);
304 struct snd_urb_ctx
*ctx
= NULL
;
308 spin_lock_irqsave(&ep
->lock
, flags
);
309 if (ep
->next_packet_read_pos
!= ep
->next_packet_write_pos
) {
310 packet
= ep
->next_packet
+ ep
->next_packet_read_pos
;
311 ep
->next_packet_read_pos
++;
312 ep
->next_packet_read_pos
%= MAX_URBS
;
314 /* take URB out of FIFO */
315 if (!list_empty(&ep
->ready_playback_urbs
))
316 ctx
= list_first_entry(&ep
->ready_playback_urbs
,
317 struct snd_urb_ctx
, ready_list
);
319 spin_unlock_irqrestore(&ep
->lock
, flags
);
324 list_del_init(&ctx
->ready_list
);
327 /* copy over the length information */
328 for (i
= 0; i
< packet
->packets
; i
++)
329 ctx
->packet_size
[i
] = packet
->packet_size
[i
];
331 /* call the data handler to fill in playback data */
332 prepare_outbound_urb(ep
, ctx
);
334 err
= usb_submit_urb(ctx
->urb
, GFP_ATOMIC
);
336 usb_audio_err(ep
->chip
,
337 "Unable to submit urb #%d: %d (urb %p)\n",
338 ctx
->index
, err
, ctx
->urb
);
340 set_bit(ctx
->index
, &ep
->active_mask
);
345 * complete callback for urbs
347 static void snd_complete_urb(struct urb
*urb
)
349 struct snd_urb_ctx
*ctx
= urb
->context
;
350 struct snd_usb_endpoint
*ep
= ctx
->ep
;
353 if (unlikely(urb
->status
== -ENOENT
|| /* unlinked */
354 urb
->status
== -ENODEV
|| /* device removed */
355 urb
->status
== -ECONNRESET
|| /* unlinked */
356 urb
->status
== -ESHUTDOWN
|| /* device disabled */
357 ep
->chip
->shutdown
)) /* device disconnected */
360 if (usb_pipeout(ep
->pipe
)) {
361 retire_outbound_urb(ep
, ctx
);
362 /* can be stopped during retire callback */
363 if (unlikely(!test_bit(EP_FLAG_RUNNING
, &ep
->flags
)))
366 if (snd_usb_endpoint_implicit_feedback_sink(ep
)) {
369 spin_lock_irqsave(&ep
->lock
, flags
);
370 list_add_tail(&ctx
->ready_list
, &ep
->ready_playback_urbs
);
371 spin_unlock_irqrestore(&ep
->lock
, flags
);
372 queue_pending_output_urbs(ep
);
377 prepare_outbound_urb(ep
, ctx
);
379 retire_inbound_urb(ep
, ctx
);
380 /* can be stopped during retire callback */
381 if (unlikely(!test_bit(EP_FLAG_RUNNING
, &ep
->flags
)))
384 prepare_inbound_urb(ep
, ctx
);
387 err
= usb_submit_urb(urb
, GFP_ATOMIC
);
391 usb_audio_err(ep
->chip
, "cannot submit urb (err = %d)\n", err
);
392 //snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
395 clear_bit(ctx
->index
, &ep
->active_mask
);
399 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
402 * @alts: The USB host interface
403 * @ep_num: The number of the endpoint to use
404 * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE
405 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
407 * If the requested endpoint has not been added to the given chip before,
408 * a new instance is created. Otherwise, a pointer to the previoulsy
409 * created instance is returned. In case of any error, NULL is returned.
411 * New endpoints will be added to chip->ep_list and must be freed by
412 * calling snd_usb_endpoint_free().
414 struct snd_usb_endpoint
*snd_usb_add_endpoint(struct snd_usb_audio
*chip
,
415 struct usb_host_interface
*alts
,
416 int ep_num
, int direction
, int type
)
418 struct snd_usb_endpoint
*ep
;
419 int is_playback
= direction
== SNDRV_PCM_STREAM_PLAYBACK
;
424 mutex_lock(&chip
->mutex
);
426 list_for_each_entry(ep
, &chip
->ep_list
, list
) {
427 if (ep
->ep_num
== ep_num
&&
428 ep
->iface
== alts
->desc
.bInterfaceNumber
&&
429 ep
->altsetting
== alts
->desc
.bAlternateSetting
) {
430 usb_audio_dbg(ep
->chip
,
431 "Re-using EP %x in iface %d,%d @%p\n",
432 ep_num
, ep
->iface
, ep
->altsetting
, ep
);
437 usb_audio_dbg(chip
, "Creating new %s %s endpoint #%x\n",
438 is_playback
? "playback" : "capture",
439 type
== SND_USB_ENDPOINT_TYPE_DATA
? "data" : "sync",
442 ep
= kzalloc(sizeof(*ep
), GFP_KERNEL
);
447 spin_lock_init(&ep
->lock
);
450 ep
->iface
= alts
->desc
.bInterfaceNumber
;
451 ep
->altsetting
= alts
->desc
.bAlternateSetting
;
452 INIT_LIST_HEAD(&ep
->ready_playback_urbs
);
453 ep_num
&= USB_ENDPOINT_NUMBER_MASK
;
456 ep
->pipe
= usb_sndisocpipe(chip
->dev
, ep_num
);
458 ep
->pipe
= usb_rcvisocpipe(chip
->dev
, ep_num
);
460 if (type
== SND_USB_ENDPOINT_TYPE_SYNC
) {
461 if (get_endpoint(alts
, 1)->bLength
>= USB_DT_ENDPOINT_AUDIO_SIZE
&&
462 get_endpoint(alts
, 1)->bRefresh
>= 1 &&
463 get_endpoint(alts
, 1)->bRefresh
<= 9)
464 ep
->syncinterval
= get_endpoint(alts
, 1)->bRefresh
;
465 else if (snd_usb_get_speed(chip
->dev
) == USB_SPEED_FULL
)
466 ep
->syncinterval
= 1;
467 else if (get_endpoint(alts
, 1)->bInterval
>= 1 &&
468 get_endpoint(alts
, 1)->bInterval
<= 16)
469 ep
->syncinterval
= get_endpoint(alts
, 1)->bInterval
- 1;
471 ep
->syncinterval
= 3;
473 ep
->syncmaxsize
= le16_to_cpu(get_endpoint(alts
, 1)->wMaxPacketSize
);
476 list_add_tail(&ep
->list
, &chip
->ep_list
);
479 mutex_unlock(&chip
->mutex
);
485 * wait until all urbs are processed.
487 static int wait_clear_urbs(struct snd_usb_endpoint
*ep
)
489 unsigned long end_time
= jiffies
+ msecs_to_jiffies(1000);
493 alive
= bitmap_weight(&ep
->active_mask
, ep
->nurbs
);
497 schedule_timeout_uninterruptible(1);
498 } while (time_before(jiffies
, end_time
));
501 usb_audio_err(ep
->chip
,
502 "timeout: still %d active urbs on EP #%x\n",
504 clear_bit(EP_FLAG_STOPPING
, &ep
->flags
);
509 /* sync the pending stop operation;
510 * this function itself doesn't trigger the stop operation
512 void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint
*ep
)
514 if (ep
&& test_bit(EP_FLAG_STOPPING
, &ep
->flags
))
519 * unlink active urbs.
521 static int deactivate_urbs(struct snd_usb_endpoint
*ep
, bool force
)
525 if (!force
&& ep
->chip
->shutdown
) /* to be sure... */
528 clear_bit(EP_FLAG_RUNNING
, &ep
->flags
);
530 INIT_LIST_HEAD(&ep
->ready_playback_urbs
);
531 ep
->next_packet_read_pos
= 0;
532 ep
->next_packet_write_pos
= 0;
534 for (i
= 0; i
< ep
->nurbs
; i
++) {
535 if (test_bit(i
, &ep
->active_mask
)) {
536 if (!test_and_set_bit(i
, &ep
->unlink_mask
)) {
537 struct urb
*u
= ep
->urb
[i
].urb
;
547 * release an endpoint's urbs
549 static void release_urbs(struct snd_usb_endpoint
*ep
, int force
)
553 /* route incoming urbs to nirvana */
554 ep
->retire_data_urb
= NULL
;
555 ep
->prepare_data_urb
= NULL
;
558 deactivate_urbs(ep
, force
);
561 for (i
= 0; i
< ep
->nurbs
; i
++)
562 release_urb_ctx(&ep
->urb
[i
]);
565 usb_free_coherent(ep
->chip
->dev
, SYNC_URBS
* 4,
566 ep
->syncbuf
, ep
->sync_dma
);
573 * configure a data endpoint
575 static int data_ep_set_params(struct snd_usb_endpoint
*ep
,
576 snd_pcm_format_t pcm_format
,
577 unsigned int channels
,
578 unsigned int period_bytes
,
579 unsigned int frames_per_period
,
580 unsigned int periods_per_buffer
,
581 struct audioformat
*fmt
,
582 struct snd_usb_endpoint
*sync_ep
)
584 unsigned int maxsize
, minsize
, packs_per_ms
, max_packs_per_urb
;
585 unsigned int max_packs_per_period
, urbs_per_period
, urb_packs
;
586 unsigned int max_urbs
, i
;
587 int frame_bits
= snd_pcm_format_physical_width(pcm_format
) * channels
;
589 if (pcm_format
== SNDRV_PCM_FORMAT_DSD_U16_LE
&& fmt
->dsd_dop
) {
591 * When operating in DSD DOP mode, the size of a sample frame
592 * in hardware differs from the actual physical format width
593 * because we need to make room for the DOP markers.
595 frame_bits
+= channels
<< 3;
598 ep
->datainterval
= fmt
->datainterval
;
599 ep
->stride
= frame_bits
>> 3;
600 ep
->silence_value
= pcm_format
== SNDRV_PCM_FORMAT_U8
? 0x80 : 0;
602 /* assume max. frequency is 25% higher than nominal */
603 ep
->freqmax
= ep
->freqn
+ (ep
->freqn
>> 2);
604 maxsize
= ((ep
->freqmax
+ 0xffff) * (frame_bits
>> 3))
605 >> (16 - ep
->datainterval
);
606 /* but wMaxPacketSize might reduce this */
607 if (ep
->maxpacksize
&& ep
->maxpacksize
< maxsize
) {
608 /* whatever fits into a max. size packet */
609 maxsize
= ep
->maxpacksize
;
610 ep
->freqmax
= (maxsize
/ (frame_bits
>> 3))
611 << (16 - ep
->datainterval
);
615 ep
->curpacksize
= ep
->maxpacksize
;
617 ep
->curpacksize
= maxsize
;
619 if (snd_usb_get_speed(ep
->chip
->dev
) != USB_SPEED_FULL
) {
620 packs_per_ms
= 8 >> ep
->datainterval
;
621 max_packs_per_urb
= MAX_PACKS_HS
;
624 max_packs_per_urb
= MAX_PACKS
;
626 if (sync_ep
&& !snd_usb_endpoint_implicit_feedback_sink(ep
))
627 max_packs_per_urb
= min(max_packs_per_urb
,
628 1U << sync_ep
->syncinterval
);
629 max_packs_per_urb
= max(1u, max_packs_per_urb
>> ep
->datainterval
);
632 * Capture endpoints need to use small URBs because there's no way
633 * to tell in advance where the next period will end, and we don't
634 * want the next URB to complete much after the period ends.
636 * Playback endpoints with implicit sync much use the same parameters
637 * as their corresponding capture endpoint.
639 if (usb_pipein(ep
->pipe
) ||
640 snd_usb_endpoint_implicit_feedback_sink(ep
)) {
642 urb_packs
= packs_per_ms
;
644 * Wireless devices can poll at a max rate of once per 4ms.
645 * For dataintervals less than 5, increase the packet count to
646 * allow the host controller to use bursting to fill in the
649 if (snd_usb_get_speed(ep
->chip
->dev
) == USB_SPEED_WIRELESS
) {
650 int interval
= ep
->datainterval
;
651 while (interval
< 5) {
656 /* make capture URBs <= 1 ms and smaller than a period */
657 urb_packs
= min(max_packs_per_urb
, urb_packs
);
658 while (urb_packs
> 1 && urb_packs
* maxsize
>= period_bytes
)
660 ep
->nurbs
= MAX_URBS
;
663 * Playback endpoints without implicit sync are adjusted so that
664 * a period fits as evenly as possible in the smallest number of
665 * URBs. The total number of URBs is adjusted to the size of the
666 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
669 /* determine how small a packet can be */
670 minsize
= (ep
->freqn
>> (16 - ep
->datainterval
)) *
672 /* with sync from device, assume it can be 12% lower */
674 minsize
-= minsize
>> 3;
675 minsize
= max(minsize
, 1u);
677 /* how many packets will contain an entire ALSA period? */
678 max_packs_per_period
= DIV_ROUND_UP(period_bytes
, minsize
);
680 /* how many URBs will contain a period? */
681 urbs_per_period
= DIV_ROUND_UP(max_packs_per_period
,
683 /* how many packets are needed in each URB? */
684 urb_packs
= DIV_ROUND_UP(max_packs_per_period
, urbs_per_period
);
686 /* limit the number of frames in a single URB */
687 ep
->max_urb_frames
= DIV_ROUND_UP(frames_per_period
,
690 /* try to use enough URBs to contain an entire ALSA buffer */
691 max_urbs
= min((unsigned) MAX_URBS
,
692 MAX_QUEUE
* packs_per_ms
/ urb_packs
);
693 ep
->nurbs
= min(max_urbs
, urbs_per_period
* periods_per_buffer
);
696 /* allocate and initialize data urbs */
697 for (i
= 0; i
< ep
->nurbs
; i
++) {
698 struct snd_urb_ctx
*u
= &ep
->urb
[i
];
701 u
->packets
= urb_packs
;
702 u
->buffer_size
= maxsize
* u
->packets
;
704 if (fmt
->fmt_type
== UAC_FORMAT_TYPE_II
)
705 u
->packets
++; /* for transfer delimiter */
706 u
->urb
= usb_alloc_urb(u
->packets
, GFP_KERNEL
);
710 u
->urb
->transfer_buffer
=
711 usb_alloc_coherent(ep
->chip
->dev
, u
->buffer_size
,
712 GFP_KERNEL
, &u
->urb
->transfer_dma
);
713 if (!u
->urb
->transfer_buffer
)
715 u
->urb
->pipe
= ep
->pipe
;
716 u
->urb
->transfer_flags
= URB_NO_TRANSFER_DMA_MAP
;
717 u
->urb
->interval
= 1 << ep
->datainterval
;
719 u
->urb
->complete
= snd_complete_urb
;
720 INIT_LIST_HEAD(&u
->ready_list
);
731 * configure a sync endpoint
733 static int sync_ep_set_params(struct snd_usb_endpoint
*ep
)
737 ep
->syncbuf
= usb_alloc_coherent(ep
->chip
->dev
, SYNC_URBS
* 4,
738 GFP_KERNEL
, &ep
->sync_dma
);
742 for (i
= 0; i
< SYNC_URBS
; i
++) {
743 struct snd_urb_ctx
*u
= &ep
->urb
[i
];
747 u
->urb
= usb_alloc_urb(1, GFP_KERNEL
);
750 u
->urb
->transfer_buffer
= ep
->syncbuf
+ i
* 4;
751 u
->urb
->transfer_dma
= ep
->sync_dma
+ i
* 4;
752 u
->urb
->transfer_buffer_length
= 4;
753 u
->urb
->pipe
= ep
->pipe
;
754 u
->urb
->transfer_flags
= URB_NO_TRANSFER_DMA_MAP
;
755 u
->urb
->number_of_packets
= 1;
756 u
->urb
->interval
= 1 << ep
->syncinterval
;
758 u
->urb
->complete
= snd_complete_urb
;
761 ep
->nurbs
= SYNC_URBS
;
771 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
773 * @ep: the snd_usb_endpoint to configure
774 * @pcm_format: the audio fomat.
775 * @channels: the number of audio channels.
776 * @period_bytes: the number of bytes in one alsa period.
777 * @period_frames: the number of frames in one alsa period.
778 * @buffer_periods: the number of periods in one alsa buffer.
779 * @rate: the frame rate.
780 * @fmt: the USB audio format information
781 * @sync_ep: the sync endpoint to use, if any
783 * Determine the number of URBs to be used on this endpoint.
784 * An endpoint must be configured before it can be started.
785 * An endpoint that is already running can not be reconfigured.
787 int snd_usb_endpoint_set_params(struct snd_usb_endpoint
*ep
,
788 snd_pcm_format_t pcm_format
,
789 unsigned int channels
,
790 unsigned int period_bytes
,
791 unsigned int period_frames
,
792 unsigned int buffer_periods
,
794 struct audioformat
*fmt
,
795 struct snd_usb_endpoint
*sync_ep
)
799 if (ep
->use_count
!= 0) {
800 usb_audio_warn(ep
->chip
,
801 "Unable to change format on ep #%x: already in use\n",
806 /* release old buffers, if any */
809 ep
->datainterval
= fmt
->datainterval
;
810 ep
->maxpacksize
= fmt
->maxpacksize
;
811 ep
->fill_max
= !!(fmt
->attributes
& UAC_EP_CS_ATTR_FILL_MAX
);
813 if (snd_usb_get_speed(ep
->chip
->dev
) == USB_SPEED_FULL
)
814 ep
->freqn
= get_usb_full_speed_rate(rate
);
816 ep
->freqn
= get_usb_high_speed_rate(rate
);
818 /* calculate the frequency in 16.16 format */
819 ep
->freqm
= ep
->freqn
;
820 ep
->freqshift
= INT_MIN
;
825 case SND_USB_ENDPOINT_TYPE_DATA
:
826 err
= data_ep_set_params(ep
, pcm_format
, channels
,
827 period_bytes
, period_frames
,
828 buffer_periods
, fmt
, sync_ep
);
830 case SND_USB_ENDPOINT_TYPE_SYNC
:
831 err
= sync_ep_set_params(ep
);
837 usb_audio_dbg(ep
->chip
,
838 "Setting params for ep #%x (type %d, %d urbs), ret=%d\n",
839 ep
->ep_num
, ep
->type
, ep
->nurbs
, err
);
845 * snd_usb_endpoint_start: start an snd_usb_endpoint
847 * @ep: the endpoint to start
848 * @can_sleep: flag indicating whether the operation is executed in
851 * A call to this function will increment the use count of the endpoint.
852 * In case it is not already running, the URBs for this endpoint will be
853 * submitted. Otherwise, this function does nothing.
855 * Must be balanced to calls of snd_usb_endpoint_stop().
857 * Returns an error if the URB submission failed, 0 in all other cases.
859 int snd_usb_endpoint_start(struct snd_usb_endpoint
*ep
, bool can_sleep
)
864 if (ep
->chip
->shutdown
)
867 /* already running? */
868 if (++ep
->use_count
!= 1)
871 /* just to be sure */
872 deactivate_urbs(ep
, false);
880 snd_usb_endpoint_start_quirk(ep
);
883 * If this endpoint has a data endpoint as implicit feedback source,
884 * don't start the urbs here. Instead, mark them all as available,
885 * wait for the record urbs to return and queue the playback urbs
889 set_bit(EP_FLAG_RUNNING
, &ep
->flags
);
891 if (snd_usb_endpoint_implicit_feedback_sink(ep
)) {
892 for (i
= 0; i
< ep
->nurbs
; i
++) {
893 struct snd_urb_ctx
*ctx
= ep
->urb
+ i
;
894 list_add_tail(&ctx
->ready_list
, &ep
->ready_playback_urbs
);
900 for (i
= 0; i
< ep
->nurbs
; i
++) {
901 struct urb
*urb
= ep
->urb
[i
].urb
;
903 if (snd_BUG_ON(!urb
))
906 if (usb_pipeout(ep
->pipe
)) {
907 prepare_outbound_urb(ep
, urb
->context
);
909 prepare_inbound_urb(ep
, urb
->context
);
912 err
= usb_submit_urb(urb
, GFP_ATOMIC
);
914 usb_audio_err(ep
->chip
,
915 "cannot submit urb %d, error %d: %s\n",
916 i
, err
, usb_error_string(err
));
919 set_bit(i
, &ep
->active_mask
);
925 clear_bit(EP_FLAG_RUNNING
, &ep
->flags
);
927 deactivate_urbs(ep
, false);
932 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
934 * @ep: the endpoint to stop (may be NULL)
936 * A call to this function will decrement the use count of the endpoint.
937 * In case the last user has requested the endpoint stop, the URBs will
938 * actually be deactivated.
940 * Must be balanced to calls of snd_usb_endpoint_start().
942 * The caller needs to synchronize the pending stop operation via
943 * snd_usb_endpoint_sync_pending_stop().
945 void snd_usb_endpoint_stop(struct snd_usb_endpoint
*ep
)
950 if (snd_BUG_ON(ep
->use_count
== 0))
953 if (--ep
->use_count
== 0) {
954 deactivate_urbs(ep
, false);
955 ep
->data_subs
= NULL
;
956 ep
->sync_slave
= NULL
;
957 ep
->retire_data_urb
= NULL
;
958 ep
->prepare_data_urb
= NULL
;
959 set_bit(EP_FLAG_STOPPING
, &ep
->flags
);
964 * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint
966 * @ep: the endpoint to deactivate
968 * If the endpoint is not currently in use, this functions will
969 * deactivate its associated URBs.
971 * In case of any active users, this functions does nothing.
973 void snd_usb_endpoint_deactivate(struct snd_usb_endpoint
*ep
)
978 if (ep
->use_count
!= 0)
981 deactivate_urbs(ep
, true);
986 * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint
988 * @ep: the list header of the endpoint to free
990 * This function does not care for the endpoint's use count but will tear
991 * down all the streaming URBs immediately and free all resources.
993 void snd_usb_endpoint_free(struct list_head
*head
)
995 struct snd_usb_endpoint
*ep
;
997 ep
= list_entry(head
, struct snd_usb_endpoint
, list
);
1003 * snd_usb_handle_sync_urb: parse an USB sync packet
1005 * @ep: the endpoint to handle the packet
1006 * @sender: the sending endpoint
1007 * @urb: the received packet
1009 * This function is called from the context of an endpoint that received
1010 * the packet and is used to let another endpoint object handle the payload.
1012 void snd_usb_handle_sync_urb(struct snd_usb_endpoint
*ep
,
1013 struct snd_usb_endpoint
*sender
,
1014 const struct urb
*urb
)
1018 unsigned long flags
;
1020 snd_BUG_ON(ep
== sender
);
1023 * In case the endpoint is operating in implicit feedback mode, prepare
1024 * a new outbound URB that has the same layout as the received packet
1025 * and add it to the list of pending urbs. queue_pending_output_urbs()
1026 * will take care of them later.
1028 if (snd_usb_endpoint_implicit_feedback_sink(ep
) &&
1029 ep
->use_count
!= 0) {
1031 /* implicit feedback case */
1033 struct snd_urb_ctx
*in_ctx
;
1034 struct snd_usb_packet_info
*out_packet
;
1036 in_ctx
= urb
->context
;
1038 /* Count overall packet size */
1039 for (i
= 0; i
< in_ctx
->packets
; i
++)
1040 if (urb
->iso_frame_desc
[i
].status
== 0)
1041 bytes
+= urb
->iso_frame_desc
[i
].actual_length
;
1044 * skip empty packets. At least M-Audio's Fast Track Ultra stops
1045 * streaming once it received a 0-byte OUT URB
1050 spin_lock_irqsave(&ep
->lock
, flags
);
1051 out_packet
= ep
->next_packet
+ ep
->next_packet_write_pos
;
1054 * Iterate through the inbound packet and prepare the lengths
1055 * for the output packet. The OUT packet we are about to send
1056 * will have the same amount of payload bytes per stride as the
1057 * IN packet we just received. Since the actual size is scaled
1058 * by the stride, use the sender stride to calculate the length
1059 * in case the number of channels differ between the implicitly
1060 * fed-back endpoint and the synchronizing endpoint.
1063 out_packet
->packets
= in_ctx
->packets
;
1064 for (i
= 0; i
< in_ctx
->packets
; i
++) {
1065 if (urb
->iso_frame_desc
[i
].status
== 0)
1066 out_packet
->packet_size
[i
] =
1067 urb
->iso_frame_desc
[i
].actual_length
/ sender
->stride
;
1069 out_packet
->packet_size
[i
] = 0;
1072 ep
->next_packet_write_pos
++;
1073 ep
->next_packet_write_pos
%= MAX_URBS
;
1074 spin_unlock_irqrestore(&ep
->lock
, flags
);
1075 queue_pending_output_urbs(ep
);
1081 * process after playback sync complete
1083 * Full speed devices report feedback values in 10.14 format as samples
1084 * per frame, high speed devices in 16.16 format as samples per
1087 * Because the Audio Class 1 spec was written before USB 2.0, many high
1088 * speed devices use a wrong interpretation, some others use an
1089 * entirely different format.
1091 * Therefore, we cannot predict what format any particular device uses
1092 * and must detect it automatically.
1095 if (urb
->iso_frame_desc
[0].status
!= 0 ||
1096 urb
->iso_frame_desc
[0].actual_length
< 3)
1099 f
= le32_to_cpup(urb
->transfer_buffer
);
1100 if (urb
->iso_frame_desc
[0].actual_length
== 3)
1108 if (unlikely(ep
->freqshift
== INT_MIN
)) {
1110 * The first time we see a feedback value, determine its format
1111 * by shifting it left or right until it matches the nominal
1112 * frequency value. This assumes that the feedback does not
1113 * differ from the nominal value more than +50% or -25%.
1116 while (f
< ep
->freqn
- ep
->freqn
/ 4) {
1120 while (f
> ep
->freqn
+ ep
->freqn
/ 2) {
1124 ep
->freqshift
= shift
;
1125 } else if (ep
->freqshift
>= 0)
1126 f
<<= ep
->freqshift
;
1128 f
>>= -ep
->freqshift
;
1130 if (likely(f
>= ep
->freqn
- ep
->freqn
/ 8 && f
<= ep
->freqmax
)) {
1132 * If the frequency looks valid, set it.
1133 * This value is referred to in prepare_playback_urb().
1135 spin_lock_irqsave(&ep
->lock
, flags
);
1137 spin_unlock_irqrestore(&ep
->lock
, flags
);
1140 * Out of range; maybe the shift value is wrong.
1141 * Reset it so that we autodetect again the next time.
1143 ep
->freqshift
= INT_MIN
;