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
;
351 struct snd_pcm_substream
*substream
;
355 if (unlikely(urb
->status
== -ENOENT
|| /* unlinked */
356 urb
->status
== -ENODEV
|| /* device removed */
357 urb
->status
== -ECONNRESET
|| /* unlinked */
358 urb
->status
== -ESHUTDOWN
)) /* device disabled */
360 /* device disconnected */
361 if (unlikely(atomic_read(&ep
->chip
->shutdown
)))
364 if (usb_pipeout(ep
->pipe
)) {
365 retire_outbound_urb(ep
, ctx
);
366 /* can be stopped during retire callback */
367 if (unlikely(!test_bit(EP_FLAG_RUNNING
, &ep
->flags
)))
370 if (snd_usb_endpoint_implicit_feedback_sink(ep
)) {
371 spin_lock_irqsave(&ep
->lock
, flags
);
372 list_add_tail(&ctx
->ready_list
, &ep
->ready_playback_urbs
);
373 spin_unlock_irqrestore(&ep
->lock
, flags
);
374 queue_pending_output_urbs(ep
);
379 prepare_outbound_urb(ep
, ctx
);
381 retire_inbound_urb(ep
, ctx
);
382 /* can be stopped during retire callback */
383 if (unlikely(!test_bit(EP_FLAG_RUNNING
, &ep
->flags
)))
386 prepare_inbound_urb(ep
, ctx
);
389 err
= usb_submit_urb(urb
, GFP_ATOMIC
);
393 usb_audio_err(ep
->chip
, "cannot submit urb (err = %d)\n", err
);
394 if (ep
->data_subs
&& ep
->data_subs
->pcm_substream
) {
395 substream
= ep
->data_subs
->pcm_substream
;
396 snd_pcm_stop_xrun(substream
);
400 clear_bit(ctx
->index
, &ep
->active_mask
);
404 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
407 * @alts: The USB host interface
408 * @ep_num: The number of the endpoint to use
409 * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE
410 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
412 * If the requested endpoint has not been added to the given chip before,
413 * a new instance is created. Otherwise, a pointer to the previoulsy
414 * created instance is returned. In case of any error, NULL is returned.
416 * New endpoints will be added to chip->ep_list and must be freed by
417 * calling snd_usb_endpoint_free().
419 struct snd_usb_endpoint
*snd_usb_add_endpoint(struct snd_usb_audio
*chip
,
420 struct usb_host_interface
*alts
,
421 int ep_num
, int direction
, int type
)
423 struct snd_usb_endpoint
*ep
;
424 int is_playback
= direction
== SNDRV_PCM_STREAM_PLAYBACK
;
429 mutex_lock(&chip
->mutex
);
431 list_for_each_entry(ep
, &chip
->ep_list
, list
) {
432 if (ep
->ep_num
== ep_num
&&
433 ep
->iface
== alts
->desc
.bInterfaceNumber
&&
434 ep
->altsetting
== alts
->desc
.bAlternateSetting
) {
435 usb_audio_dbg(ep
->chip
,
436 "Re-using EP %x in iface %d,%d @%p\n",
437 ep_num
, ep
->iface
, ep
->altsetting
, ep
);
442 usb_audio_dbg(chip
, "Creating new %s %s endpoint #%x\n",
443 is_playback
? "playback" : "capture",
444 type
== SND_USB_ENDPOINT_TYPE_DATA
? "data" : "sync",
447 ep
= kzalloc(sizeof(*ep
), GFP_KERNEL
);
452 spin_lock_init(&ep
->lock
);
455 ep
->iface
= alts
->desc
.bInterfaceNumber
;
456 ep
->altsetting
= alts
->desc
.bAlternateSetting
;
457 INIT_LIST_HEAD(&ep
->ready_playback_urbs
);
458 ep_num
&= USB_ENDPOINT_NUMBER_MASK
;
461 ep
->pipe
= usb_sndisocpipe(chip
->dev
, ep_num
);
463 ep
->pipe
= usb_rcvisocpipe(chip
->dev
, ep_num
);
465 if (type
== SND_USB_ENDPOINT_TYPE_SYNC
) {
466 if (get_endpoint(alts
, 1)->bLength
>= USB_DT_ENDPOINT_AUDIO_SIZE
&&
467 get_endpoint(alts
, 1)->bRefresh
>= 1 &&
468 get_endpoint(alts
, 1)->bRefresh
<= 9)
469 ep
->syncinterval
= get_endpoint(alts
, 1)->bRefresh
;
470 else if (snd_usb_get_speed(chip
->dev
) == USB_SPEED_FULL
)
471 ep
->syncinterval
= 1;
472 else if (get_endpoint(alts
, 1)->bInterval
>= 1 &&
473 get_endpoint(alts
, 1)->bInterval
<= 16)
474 ep
->syncinterval
= get_endpoint(alts
, 1)->bInterval
- 1;
476 ep
->syncinterval
= 3;
478 ep
->syncmaxsize
= le16_to_cpu(get_endpoint(alts
, 1)->wMaxPacketSize
);
480 if (chip
->usb_id
== USB_ID(0x0644, 0x8038) /* TEAC UD-H01 */ &&
481 ep
->syncmaxsize
== 4)
482 ep
->udh01_fb_quirk
= 1;
485 list_add_tail(&ep
->list
, &chip
->ep_list
);
488 mutex_unlock(&chip
->mutex
);
494 * wait until all urbs are processed.
496 static int wait_clear_urbs(struct snd_usb_endpoint
*ep
)
498 unsigned long end_time
= jiffies
+ msecs_to_jiffies(1000);
502 alive
= bitmap_weight(&ep
->active_mask
, ep
->nurbs
);
506 schedule_timeout_uninterruptible(1);
507 } while (time_before(jiffies
, end_time
));
510 usb_audio_err(ep
->chip
,
511 "timeout: still %d active urbs on EP #%x\n",
513 clear_bit(EP_FLAG_STOPPING
, &ep
->flags
);
518 /* sync the pending stop operation;
519 * this function itself doesn't trigger the stop operation
521 void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint
*ep
)
523 if (ep
&& test_bit(EP_FLAG_STOPPING
, &ep
->flags
))
528 * unlink active urbs.
530 static int deactivate_urbs(struct snd_usb_endpoint
*ep
, bool force
)
534 if (!force
&& atomic_read(&ep
->chip
->shutdown
)) /* to be sure... */
537 clear_bit(EP_FLAG_RUNNING
, &ep
->flags
);
539 INIT_LIST_HEAD(&ep
->ready_playback_urbs
);
540 ep
->next_packet_read_pos
= 0;
541 ep
->next_packet_write_pos
= 0;
543 for (i
= 0; i
< ep
->nurbs
; i
++) {
544 if (test_bit(i
, &ep
->active_mask
)) {
545 if (!test_and_set_bit(i
, &ep
->unlink_mask
)) {
546 struct urb
*u
= ep
->urb
[i
].urb
;
556 * release an endpoint's urbs
558 static void release_urbs(struct snd_usb_endpoint
*ep
, int force
)
562 /* route incoming urbs to nirvana */
563 ep
->retire_data_urb
= NULL
;
564 ep
->prepare_data_urb
= NULL
;
567 deactivate_urbs(ep
, force
);
570 for (i
= 0; i
< ep
->nurbs
; i
++)
571 release_urb_ctx(&ep
->urb
[i
]);
574 usb_free_coherent(ep
->chip
->dev
, SYNC_URBS
* 4,
575 ep
->syncbuf
, ep
->sync_dma
);
582 * configure a data endpoint
584 static int data_ep_set_params(struct snd_usb_endpoint
*ep
,
585 snd_pcm_format_t pcm_format
,
586 unsigned int channels
,
587 unsigned int period_bytes
,
588 unsigned int frames_per_period
,
589 unsigned int periods_per_buffer
,
590 struct audioformat
*fmt
,
591 struct snd_usb_endpoint
*sync_ep
)
593 unsigned int maxsize
, minsize
, packs_per_ms
, max_packs_per_urb
;
594 unsigned int max_packs_per_period
, urbs_per_period
, urb_packs
;
595 unsigned int max_urbs
, i
;
596 int frame_bits
= snd_pcm_format_physical_width(pcm_format
) * channels
;
598 if (pcm_format
== SNDRV_PCM_FORMAT_DSD_U16_LE
&& fmt
->dsd_dop
) {
600 * When operating in DSD DOP mode, the size of a sample frame
601 * in hardware differs from the actual physical format width
602 * because we need to make room for the DOP markers.
604 frame_bits
+= channels
<< 3;
607 ep
->datainterval
= fmt
->datainterval
;
608 ep
->stride
= frame_bits
>> 3;
609 ep
->silence_value
= pcm_format
== SNDRV_PCM_FORMAT_U8
? 0x80 : 0;
611 /* assume max. frequency is 25% higher than nominal */
612 ep
->freqmax
= ep
->freqn
+ (ep
->freqn
>> 2);
613 maxsize
= ((ep
->freqmax
+ 0xffff) * (frame_bits
>> 3))
614 >> (16 - ep
->datainterval
);
615 /* but wMaxPacketSize might reduce this */
616 if (ep
->maxpacksize
&& ep
->maxpacksize
< maxsize
) {
617 /* whatever fits into a max. size packet */
618 maxsize
= ep
->maxpacksize
;
619 ep
->freqmax
= (maxsize
/ (frame_bits
>> 3))
620 << (16 - ep
->datainterval
);
624 ep
->curpacksize
= ep
->maxpacksize
;
626 ep
->curpacksize
= maxsize
;
628 if (snd_usb_get_speed(ep
->chip
->dev
) != USB_SPEED_FULL
) {
629 packs_per_ms
= 8 >> ep
->datainterval
;
630 max_packs_per_urb
= MAX_PACKS_HS
;
633 max_packs_per_urb
= MAX_PACKS
;
635 if (sync_ep
&& !snd_usb_endpoint_implicit_feedback_sink(ep
))
636 max_packs_per_urb
= min(max_packs_per_urb
,
637 1U << sync_ep
->syncinterval
);
638 max_packs_per_urb
= max(1u, max_packs_per_urb
>> ep
->datainterval
);
641 * Capture endpoints need to use small URBs because there's no way
642 * to tell in advance where the next period will end, and we don't
643 * want the next URB to complete much after the period ends.
645 * Playback endpoints with implicit sync much use the same parameters
646 * as their corresponding capture endpoint.
648 if (usb_pipein(ep
->pipe
) ||
649 snd_usb_endpoint_implicit_feedback_sink(ep
)) {
651 urb_packs
= packs_per_ms
;
653 * Wireless devices can poll at a max rate of once per 4ms.
654 * For dataintervals less than 5, increase the packet count to
655 * allow the host controller to use bursting to fill in the
658 if (snd_usb_get_speed(ep
->chip
->dev
) == USB_SPEED_WIRELESS
) {
659 int interval
= ep
->datainterval
;
660 while (interval
< 5) {
665 /* make capture URBs <= 1 ms and smaller than a period */
666 urb_packs
= min(max_packs_per_urb
, urb_packs
);
667 while (urb_packs
> 1 && urb_packs
* maxsize
>= period_bytes
)
669 ep
->nurbs
= MAX_URBS
;
672 * Playback endpoints without implicit sync are adjusted so that
673 * a period fits as evenly as possible in the smallest number of
674 * URBs. The total number of URBs is adjusted to the size of the
675 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
678 /* determine how small a packet can be */
679 minsize
= (ep
->freqn
>> (16 - ep
->datainterval
)) *
681 /* with sync from device, assume it can be 12% lower */
683 minsize
-= minsize
>> 3;
684 minsize
= max(minsize
, 1u);
686 /* how many packets will contain an entire ALSA period? */
687 max_packs_per_period
= DIV_ROUND_UP(period_bytes
, minsize
);
689 /* how many URBs will contain a period? */
690 urbs_per_period
= DIV_ROUND_UP(max_packs_per_period
,
692 /* how many packets are needed in each URB? */
693 urb_packs
= DIV_ROUND_UP(max_packs_per_period
, urbs_per_period
);
695 /* limit the number of frames in a single URB */
696 ep
->max_urb_frames
= DIV_ROUND_UP(frames_per_period
,
699 /* try to use enough URBs to contain an entire ALSA buffer */
700 max_urbs
= min((unsigned) MAX_URBS
,
701 MAX_QUEUE
* packs_per_ms
/ urb_packs
);
702 ep
->nurbs
= min(max_urbs
, urbs_per_period
* periods_per_buffer
);
705 /* allocate and initialize data urbs */
706 for (i
= 0; i
< ep
->nurbs
; i
++) {
707 struct snd_urb_ctx
*u
= &ep
->urb
[i
];
710 u
->packets
= urb_packs
;
711 u
->buffer_size
= maxsize
* u
->packets
;
713 if (fmt
->fmt_type
== UAC_FORMAT_TYPE_II
)
714 u
->packets
++; /* for transfer delimiter */
715 u
->urb
= usb_alloc_urb(u
->packets
, GFP_KERNEL
);
719 u
->urb
->transfer_buffer
=
720 usb_alloc_coherent(ep
->chip
->dev
, u
->buffer_size
,
721 GFP_KERNEL
, &u
->urb
->transfer_dma
);
722 if (!u
->urb
->transfer_buffer
)
724 u
->urb
->pipe
= ep
->pipe
;
725 u
->urb
->transfer_flags
= URB_NO_TRANSFER_DMA_MAP
;
726 u
->urb
->interval
= 1 << ep
->datainterval
;
728 u
->urb
->complete
= snd_complete_urb
;
729 INIT_LIST_HEAD(&u
->ready_list
);
740 * configure a sync endpoint
742 static int sync_ep_set_params(struct snd_usb_endpoint
*ep
)
746 ep
->syncbuf
= usb_alloc_coherent(ep
->chip
->dev
, SYNC_URBS
* 4,
747 GFP_KERNEL
, &ep
->sync_dma
);
751 for (i
= 0; i
< SYNC_URBS
; i
++) {
752 struct snd_urb_ctx
*u
= &ep
->urb
[i
];
756 u
->urb
= usb_alloc_urb(1, GFP_KERNEL
);
759 u
->urb
->transfer_buffer
= ep
->syncbuf
+ i
* 4;
760 u
->urb
->transfer_dma
= ep
->sync_dma
+ i
* 4;
761 u
->urb
->transfer_buffer_length
= 4;
762 u
->urb
->pipe
= ep
->pipe
;
763 u
->urb
->transfer_flags
= URB_NO_TRANSFER_DMA_MAP
;
764 u
->urb
->number_of_packets
= 1;
765 u
->urb
->interval
= 1 << ep
->syncinterval
;
767 u
->urb
->complete
= snd_complete_urb
;
770 ep
->nurbs
= SYNC_URBS
;
780 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
782 * @ep: the snd_usb_endpoint to configure
783 * @pcm_format: the audio fomat.
784 * @channels: the number of audio channels.
785 * @period_bytes: the number of bytes in one alsa period.
786 * @period_frames: the number of frames in one alsa period.
787 * @buffer_periods: the number of periods in one alsa buffer.
788 * @rate: the frame rate.
789 * @fmt: the USB audio format information
790 * @sync_ep: the sync endpoint to use, if any
792 * Determine the number of URBs to be used on this endpoint.
793 * An endpoint must be configured before it can be started.
794 * An endpoint that is already running can not be reconfigured.
796 int snd_usb_endpoint_set_params(struct snd_usb_endpoint
*ep
,
797 snd_pcm_format_t pcm_format
,
798 unsigned int channels
,
799 unsigned int period_bytes
,
800 unsigned int period_frames
,
801 unsigned int buffer_periods
,
803 struct audioformat
*fmt
,
804 struct snd_usb_endpoint
*sync_ep
)
808 if (ep
->use_count
!= 0) {
809 usb_audio_warn(ep
->chip
,
810 "Unable to change format on ep #%x: already in use\n",
815 /* release old buffers, if any */
818 ep
->datainterval
= fmt
->datainterval
;
819 ep
->maxpacksize
= fmt
->maxpacksize
;
820 ep
->fill_max
= !!(fmt
->attributes
& UAC_EP_CS_ATTR_FILL_MAX
);
822 if (snd_usb_get_speed(ep
->chip
->dev
) == USB_SPEED_FULL
)
823 ep
->freqn
= get_usb_full_speed_rate(rate
);
825 ep
->freqn
= get_usb_high_speed_rate(rate
);
827 /* calculate the frequency in 16.16 format */
828 ep
->freqm
= ep
->freqn
;
829 ep
->freqshift
= INT_MIN
;
834 case SND_USB_ENDPOINT_TYPE_DATA
:
835 err
= data_ep_set_params(ep
, pcm_format
, channels
,
836 period_bytes
, period_frames
,
837 buffer_periods
, fmt
, sync_ep
);
839 case SND_USB_ENDPOINT_TYPE_SYNC
:
840 err
= sync_ep_set_params(ep
);
846 usb_audio_dbg(ep
->chip
,
847 "Setting params for ep #%x (type %d, %d urbs), ret=%d\n",
848 ep
->ep_num
, ep
->type
, ep
->nurbs
, err
);
854 * snd_usb_endpoint_start: start an snd_usb_endpoint
856 * @ep: the endpoint to start
857 * @can_sleep: flag indicating whether the operation is executed in
860 * A call to this function will increment the use count of the endpoint.
861 * In case it is not already running, the URBs for this endpoint will be
862 * submitted. Otherwise, this function does nothing.
864 * Must be balanced to calls of snd_usb_endpoint_stop().
866 * Returns an error if the URB submission failed, 0 in all other cases.
868 int snd_usb_endpoint_start(struct snd_usb_endpoint
*ep
, bool can_sleep
)
873 if (atomic_read(&ep
->chip
->shutdown
))
876 /* already running? */
877 if (++ep
->use_count
!= 1)
880 /* just to be sure */
881 deactivate_urbs(ep
, false);
889 snd_usb_endpoint_start_quirk(ep
);
892 * If this endpoint has a data endpoint as implicit feedback source,
893 * don't start the urbs here. Instead, mark them all as available,
894 * wait for the record urbs to return and queue the playback urbs
898 set_bit(EP_FLAG_RUNNING
, &ep
->flags
);
900 if (snd_usb_endpoint_implicit_feedback_sink(ep
)) {
901 for (i
= 0; i
< ep
->nurbs
; i
++) {
902 struct snd_urb_ctx
*ctx
= ep
->urb
+ i
;
903 list_add_tail(&ctx
->ready_list
, &ep
->ready_playback_urbs
);
909 for (i
= 0; i
< ep
->nurbs
; i
++) {
910 struct urb
*urb
= ep
->urb
[i
].urb
;
912 if (snd_BUG_ON(!urb
))
915 if (usb_pipeout(ep
->pipe
)) {
916 prepare_outbound_urb(ep
, urb
->context
);
918 prepare_inbound_urb(ep
, urb
->context
);
921 err
= usb_submit_urb(urb
, GFP_ATOMIC
);
923 usb_audio_err(ep
->chip
,
924 "cannot submit urb %d, error %d: %s\n",
925 i
, err
, usb_error_string(err
));
928 set_bit(i
, &ep
->active_mask
);
934 clear_bit(EP_FLAG_RUNNING
, &ep
->flags
);
936 deactivate_urbs(ep
, false);
941 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
943 * @ep: the endpoint to stop (may be NULL)
945 * A call to this function will decrement the use count of the endpoint.
946 * In case the last user has requested the endpoint stop, the URBs will
947 * actually be deactivated.
949 * Must be balanced to calls of snd_usb_endpoint_start().
951 * The caller needs to synchronize the pending stop operation via
952 * snd_usb_endpoint_sync_pending_stop().
954 void snd_usb_endpoint_stop(struct snd_usb_endpoint
*ep
)
959 if (snd_BUG_ON(ep
->use_count
== 0))
962 if (--ep
->use_count
== 0) {
963 deactivate_urbs(ep
, false);
964 ep
->data_subs
= NULL
;
965 ep
->sync_slave
= NULL
;
966 ep
->retire_data_urb
= NULL
;
967 ep
->prepare_data_urb
= NULL
;
968 set_bit(EP_FLAG_STOPPING
, &ep
->flags
);
973 * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint
975 * @ep: the endpoint to deactivate
977 * If the endpoint is not currently in use, this functions will
978 * deactivate its associated URBs.
980 * In case of any active users, this functions does nothing.
982 void snd_usb_endpoint_deactivate(struct snd_usb_endpoint
*ep
)
987 if (ep
->use_count
!= 0)
990 deactivate_urbs(ep
, true);
995 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
997 * @ep: the endpoint to release
999 * This function does not care for the endpoint's use count but will tear
1000 * down all the streaming URBs immediately.
1002 void snd_usb_endpoint_release(struct snd_usb_endpoint
*ep
)
1004 release_urbs(ep
, 1);
1008 * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint
1010 * @ep: the endpoint to free
1012 * This free all resources of the given ep.
1014 void snd_usb_endpoint_free(struct snd_usb_endpoint
*ep
)
1020 * snd_usb_handle_sync_urb: parse an USB sync packet
1022 * @ep: the endpoint to handle the packet
1023 * @sender: the sending endpoint
1024 * @urb: the received packet
1026 * This function is called from the context of an endpoint that received
1027 * the packet and is used to let another endpoint object handle the payload.
1029 void snd_usb_handle_sync_urb(struct snd_usb_endpoint
*ep
,
1030 struct snd_usb_endpoint
*sender
,
1031 const struct urb
*urb
)
1035 unsigned long flags
;
1037 snd_BUG_ON(ep
== sender
);
1040 * In case the endpoint is operating in implicit feedback mode, prepare
1041 * a new outbound URB that has the same layout as the received packet
1042 * and add it to the list of pending urbs. queue_pending_output_urbs()
1043 * will take care of them later.
1045 if (snd_usb_endpoint_implicit_feedback_sink(ep
) &&
1046 ep
->use_count
!= 0) {
1048 /* implicit feedback case */
1050 struct snd_urb_ctx
*in_ctx
;
1051 struct snd_usb_packet_info
*out_packet
;
1053 in_ctx
= urb
->context
;
1055 /* Count overall packet size */
1056 for (i
= 0; i
< in_ctx
->packets
; i
++)
1057 if (urb
->iso_frame_desc
[i
].status
== 0)
1058 bytes
+= urb
->iso_frame_desc
[i
].actual_length
;
1061 * skip empty packets. At least M-Audio's Fast Track Ultra stops
1062 * streaming once it received a 0-byte OUT URB
1067 spin_lock_irqsave(&ep
->lock
, flags
);
1068 out_packet
= ep
->next_packet
+ ep
->next_packet_write_pos
;
1071 * Iterate through the inbound packet and prepare the lengths
1072 * for the output packet. The OUT packet we are about to send
1073 * will have the same amount of payload bytes per stride as the
1074 * IN packet we just received. Since the actual size is scaled
1075 * by the stride, use the sender stride to calculate the length
1076 * in case the number of channels differ between the implicitly
1077 * fed-back endpoint and the synchronizing endpoint.
1080 out_packet
->packets
= in_ctx
->packets
;
1081 for (i
= 0; i
< in_ctx
->packets
; i
++) {
1082 if (urb
->iso_frame_desc
[i
].status
== 0)
1083 out_packet
->packet_size
[i
] =
1084 urb
->iso_frame_desc
[i
].actual_length
/ sender
->stride
;
1086 out_packet
->packet_size
[i
] = 0;
1089 ep
->next_packet_write_pos
++;
1090 ep
->next_packet_write_pos
%= MAX_URBS
;
1091 spin_unlock_irqrestore(&ep
->lock
, flags
);
1092 queue_pending_output_urbs(ep
);
1098 * process after playback sync complete
1100 * Full speed devices report feedback values in 10.14 format as samples
1101 * per frame, high speed devices in 16.16 format as samples per
1104 * Because the Audio Class 1 spec was written before USB 2.0, many high
1105 * speed devices use a wrong interpretation, some others use an
1106 * entirely different format.
1108 * Therefore, we cannot predict what format any particular device uses
1109 * and must detect it automatically.
1112 if (urb
->iso_frame_desc
[0].status
!= 0 ||
1113 urb
->iso_frame_desc
[0].actual_length
< 3)
1116 f
= le32_to_cpup(urb
->transfer_buffer
);
1117 if (urb
->iso_frame_desc
[0].actual_length
== 3)
1125 if (unlikely(sender
->udh01_fb_quirk
)) {
1127 * The TEAC UD-H01 firmware sometimes changes the feedback value
1130 if (f
< ep
->freqn
- 0x8000)
1132 else if (f
> ep
->freqn
+ 0x8000)
1134 } else if (unlikely(ep
->freqshift
== INT_MIN
)) {
1136 * The first time we see a feedback value, determine its format
1137 * by shifting it left or right until it matches the nominal
1138 * frequency value. This assumes that the feedback does not
1139 * differ from the nominal value more than +50% or -25%.
1142 while (f
< ep
->freqn
- ep
->freqn
/ 4) {
1146 while (f
> ep
->freqn
+ ep
->freqn
/ 2) {
1150 ep
->freqshift
= shift
;
1151 } else if (ep
->freqshift
>= 0)
1152 f
<<= ep
->freqshift
;
1154 f
>>= -ep
->freqshift
;
1156 if (likely(f
>= ep
->freqn
- ep
->freqn
/ 8 && f
<= ep
->freqmax
)) {
1158 * If the frequency looks valid, set it.
1159 * This value is referred to in prepare_playback_urb().
1161 spin_lock_irqsave(&ep
->lock
, flags
);
1163 spin_unlock_irqrestore(&ep
->lock
, flags
);
1166 * Out of range; maybe the shift value is wrong.
1167 * Reset it so that we autodetect again the next time.
1169 ep
->freqshift
= INT_MIN
;