1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 */
4
5 #include <linux/gfp.h>
6 #include <linux/init.h>
7 #include <linux/ratelimit.h>
8 #include <linux/usb.h>
9 #include <linux/usb/audio.h>
10 #include <linux/slab.h>
11
12 #include <sound/core.h>
13 #include <sound/pcm.h>
14 #include <sound/pcm_params.h>
15
16 #include "usbaudio.h"
17 #include "helper.h"
18 #include "card.h"
19 #include "endpoint.h"
20 #include "pcm.h"
21 #include "clock.h"
22 #include "quirks.h"
23
24 enum {
25 EP_STATE_STOPPED,
26 EP_STATE_RUNNING,
27 EP_STATE_STOPPING,
28 };
29
30 /* interface refcounting */
31 struct snd_usb_iface_ref {
32 unsigned char iface;
33 bool need_setup;
34 int opened;
35 int altset;
36 struct list_head list;
37 };
38
39 /* clock refcounting */
40 struct snd_usb_clock_ref {
41 unsigned char clock;
42 atomic_t locked;
43 int opened;
44 int rate;
45 bool need_setup;
46 struct list_head list;
47 };
48
49 /*
50 * snd_usb_endpoint is a model that abstracts everything related to an
51 * USB endpoint and its streaming.
52 *
53 * There are functions to activate and deactivate the streaming URBs and
54 * optional callbacks to let the pcm logic handle the actual content of the
55 * packets for playback and record. Thus, the bus streaming and the audio
56 * handlers are fully decoupled.
57 *
58 * There are two different types of endpoints in audio applications.
59 *
60 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both
61 * inbound and outbound traffic.
62 *
63 * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and
64 * expect the payload to carry Q10.14 / Q16.16 formatted sync information
65 * (3 or 4 bytes).
66 *
67 * Each endpoint has to be configured prior to being used by calling
68 * snd_usb_endpoint_set_params().
69 *
70 * The model incorporates a reference counting, so that multiple users
71 * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and
72 * only the first user will effectively start the URBs, and only the last
73 * one to stop it will tear the URBs down again.
74 */
75
76 /*
77 * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
78 * this will overflow at approx 524 kHz
79 */
get_usb_full_speed_rate(unsigned int rate)80 static inline unsigned get_usb_full_speed_rate(unsigned int rate)
81 {
82 return ((rate << 13) + 62) / 125;
83 }
84
85 /*
86 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
87 * this will overflow at approx 4 MHz
88 */
get_usb_high_speed_rate(unsigned int rate)89 static inline unsigned get_usb_high_speed_rate(unsigned int rate)
90 {
91 return ((rate << 10) + 62) / 125;
92 }
93
94 /*
95 * release a urb data
96 */
release_urb_ctx(struct snd_urb_ctx * u)97 static void release_urb_ctx(struct snd_urb_ctx *u)
98 {
99 if (u->urb && u->buffer_size)
100 usb_free_coherent(u->ep->chip->dev, u->buffer_size,
101 u->urb->transfer_buffer,
102 u->urb->transfer_dma);
103 usb_free_urb(u->urb);
104 u->urb = NULL;
105 u->buffer_size = 0;
106 }
107
usb_error_string(int err)108 static const char *usb_error_string(int err)
109 {
110 switch (err) {
111 case -ENODEV:
112 return "no device";
113 case -ENOENT:
114 return "endpoint not enabled";
115 case -EPIPE:
116 return "endpoint stalled";
117 case -ENOSPC:
118 return "not enough bandwidth";
119 case -ESHUTDOWN:
120 return "device disabled";
121 case -EHOSTUNREACH:
122 return "device suspended";
123 case -EINVAL:
124 case -EAGAIN:
125 case -EFBIG:
126 case -EMSGSIZE:
127 return "internal error";
128 default:
129 return "unknown error";
130 }
131 }
132
ep_state_running(struct snd_usb_endpoint * ep)133 static inline bool ep_state_running(struct snd_usb_endpoint *ep)
134 {
135 return atomic_read(&ep->state) == EP_STATE_RUNNING;
136 }
137
ep_state_update(struct snd_usb_endpoint * ep,int old,int new)138 static inline bool ep_state_update(struct snd_usb_endpoint *ep, int old, int new)
139 {
140 return atomic_try_cmpxchg(&ep->state, &old, new);
141 }
142
143 /**
144 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type
145 *
146 * @ep: The snd_usb_endpoint
147 *
148 * Determine whether an endpoint is driven by an implicit feedback
149 * data endpoint source.
150 */
snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint * ep)151 int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep)
152 {
153 return ep->implicit_fb_sync && usb_pipeout(ep->pipe);
154 }
155
156 /*
157 * Return the number of samples to be sent in the next packet
158 * for streaming based on information derived from sync endpoints
159 *
160 * This won't be used for implicit feedback which takes the packet size
161 * returned from the sync source
162 */
slave_next_packet_size(struct snd_usb_endpoint * ep,unsigned int avail)163 static int slave_next_packet_size(struct snd_usb_endpoint *ep,
164 unsigned int avail)
165 {
166 unsigned long flags;
167 unsigned int phase;
168 int ret;
169
170 if (ep->fill_max)
171 return ep->maxframesize;
172
173 spin_lock_irqsave(&ep->lock, flags);
174 phase = (ep->phase & 0xffff) + (ep->freqm << ep->datainterval);
175 ret = min(phase >> 16, ep->maxframesize);
176 if (avail && ret >= avail)
177 ret = -EAGAIN;
178 else
179 ep->phase = phase;
180 spin_unlock_irqrestore(&ep->lock, flags);
181
182 return ret;
183 }
184
185 /*
186 * Return the number of samples to be sent in the next packet
187 * for adaptive and synchronous endpoints
188 */
next_packet_size(struct snd_usb_endpoint * ep,unsigned int avail)189 static int next_packet_size(struct snd_usb_endpoint *ep, unsigned int avail)
190 {
191 unsigned int sample_accum;
192 int ret;
193
194 if (ep->fill_max)
195 return ep->maxframesize;
196
197 sample_accum = ep->sample_accum + ep->sample_rem;
198 if (sample_accum >= ep->pps) {
199 sample_accum -= ep->pps;
200 ret = ep->packsize[1];
201 } else {
202 ret = ep->packsize[0];
203 }
204 if (avail && ret >= avail)
205 ret = -EAGAIN;
206 else
207 ep->sample_accum = sample_accum;
208
209 return ret;
210 }
211
212 /*
213 * snd_usb_endpoint_next_packet_size: Return the number of samples to be sent
214 * in the next packet
215 *
216 * If the size is equal or exceeds @avail, don't proceed but return -EAGAIN
217 * Exception: @avail = 0 for skipping the check.
218 */
snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint * ep,struct snd_urb_ctx * ctx,int idx,unsigned int avail)219 int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep,
220 struct snd_urb_ctx *ctx, int idx,
221 unsigned int avail)
222 {
223 unsigned int packet;
224
225 packet = ctx->packet_size[idx];
226 if (packet) {
227 if (avail && packet >= avail)
228 return -EAGAIN;
229 return packet;
230 }
231
232 if (ep->sync_source)
233 return slave_next_packet_size(ep, avail);
234 else
235 return next_packet_size(ep, avail);
236 }
237
call_retire_callback(struct snd_usb_endpoint * ep,struct urb * urb)238 static void call_retire_callback(struct snd_usb_endpoint *ep,
239 struct urb *urb)
240 {
241 struct snd_usb_substream *data_subs;
242
243 data_subs = READ_ONCE(ep->data_subs);
244 if (data_subs && ep->retire_data_urb)
245 ep->retire_data_urb(data_subs, urb);
246 }
247
retire_outbound_urb(struct snd_usb_endpoint * ep,struct snd_urb_ctx * urb_ctx)248 static void retire_outbound_urb(struct snd_usb_endpoint *ep,
249 struct snd_urb_ctx *urb_ctx)
250 {
251 call_retire_callback(ep, urb_ctx->urb);
252 }
253
254 static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
255 struct snd_usb_endpoint *sender,
256 const struct urb *urb);
257
retire_inbound_urb(struct snd_usb_endpoint * ep,struct snd_urb_ctx * urb_ctx)258 static void retire_inbound_urb(struct snd_usb_endpoint *ep,
259 struct snd_urb_ctx *urb_ctx)
260 {
261 struct urb *urb = urb_ctx->urb;
262 struct snd_usb_endpoint *sync_sink;
263
264 if (unlikely(ep->skip_packets > 0)) {
265 ep->skip_packets--;
266 return;
267 }
268
269 sync_sink = READ_ONCE(ep->sync_sink);
270 if (sync_sink)
271 snd_usb_handle_sync_urb(sync_sink, ep, urb);
272
273 call_retire_callback(ep, urb);
274 }
275
has_tx_length_quirk(struct snd_usb_audio * chip)276 static inline bool has_tx_length_quirk(struct snd_usb_audio *chip)
277 {
278 return chip->quirk_flags & QUIRK_FLAG_TX_LENGTH;
279 }
280
prepare_silent_urb(struct snd_usb_endpoint * ep,struct snd_urb_ctx * ctx)281 static void prepare_silent_urb(struct snd_usb_endpoint *ep,
282 struct snd_urb_ctx *ctx)
283 {
284 struct urb *urb = ctx->urb;
285 unsigned int offs = 0;
286 unsigned int extra = 0;
287 __le32 packet_length;
288 int i;
289
290 /* For tx_length_quirk, put packet length at start of packet */
291 if (has_tx_length_quirk(ep->chip))
292 extra = sizeof(packet_length);
293
294 for (i = 0; i < ctx->packets; ++i) {
295 unsigned int offset;
296 unsigned int length;
297 int counts;
298
299 counts = snd_usb_endpoint_next_packet_size(ep, ctx, i, 0);
300 length = counts * ep->stride; /* number of silent bytes */
301 offset = offs * ep->stride + extra * i;
302 urb->iso_frame_desc[i].offset = offset;
303 urb->iso_frame_desc[i].length = length + extra;
304 if (extra) {
305 packet_length = cpu_to_le32(length);
306 memcpy(urb->transfer_buffer + offset,
307 &packet_length, sizeof(packet_length));
308 }
309 memset(urb->transfer_buffer + offset + extra,
310 ep->silence_value, length);
311 offs += counts;
312 }
313
314 urb->number_of_packets = ctx->packets;
315 urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra;
316 ctx->queued = 0;
317 }
318
319 /*
320 * Prepare a PLAYBACK urb for submission to the bus.
321 */
prepare_outbound_urb(struct snd_usb_endpoint * ep,struct snd_urb_ctx * ctx,bool in_stream_lock)322 static int prepare_outbound_urb(struct snd_usb_endpoint *ep,
323 struct snd_urb_ctx *ctx,
324 bool in_stream_lock)
325 {
326 struct urb *urb = ctx->urb;
327 unsigned char *cp = urb->transfer_buffer;
328 struct snd_usb_substream *data_subs;
329
330 urb->dev = ep->chip->dev; /* we need to set this at each time */
331
332 switch (ep->type) {
333 case SND_USB_ENDPOINT_TYPE_DATA:
334 data_subs = READ_ONCE(ep->data_subs);
335 if (data_subs && ep->prepare_data_urb)
336 return ep->prepare_data_urb(data_subs, urb, in_stream_lock);
337 /* no data provider, so send silence */
338 prepare_silent_urb(ep, ctx);
339 break;
340
341 case SND_USB_ENDPOINT_TYPE_SYNC:
342 if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) {
343 /*
344 * fill the length and offset of each urb descriptor.
345 * the fixed 12.13 frequency is passed as 16.16 through the pipe.
346 */
347 urb->iso_frame_desc[0].length = 4;
348 urb->iso_frame_desc[0].offset = 0;
349 cp[0] = ep->freqn;
350 cp[1] = ep->freqn >> 8;
351 cp[2] = ep->freqn >> 16;
352 cp[3] = ep->freqn >> 24;
353 } else {
354 /*
355 * fill the length and offset of each urb descriptor.
356 * the fixed 10.14 frequency is passed through the pipe.
357 */
358 urb->iso_frame_desc[0].length = 3;
359 urb->iso_frame_desc[0].offset = 0;
360 cp[0] = ep->freqn >> 2;
361 cp[1] = ep->freqn >> 10;
362 cp[2] = ep->freqn >> 18;
363 }
364
365 break;
366 }
367 return 0;
368 }
369
370 /*
371 * Prepare a CAPTURE or SYNC urb for submission to the bus.
372 */
prepare_inbound_urb(struct snd_usb_endpoint * ep,struct snd_urb_ctx * urb_ctx)373 static int prepare_inbound_urb(struct snd_usb_endpoint *ep,
374 struct snd_urb_ctx *urb_ctx)
375 {
376 int i, offs;
377 struct urb *urb = urb_ctx->urb;
378
379 urb->dev = ep->chip->dev; /* we need to set this at each time */
380
381 switch (ep->type) {
382 case SND_USB_ENDPOINT_TYPE_DATA:
383 offs = 0;
384 for (i = 0; i < urb_ctx->packets; i++) {
385 urb->iso_frame_desc[i].offset = offs;
386 urb->iso_frame_desc[i].length = ep->curpacksize;
387 offs += ep->curpacksize;
388 }
389
390 urb->transfer_buffer_length = offs;
391 urb->number_of_packets = urb_ctx->packets;
392 break;
393
394 case SND_USB_ENDPOINT_TYPE_SYNC:
395 urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize);
396 urb->iso_frame_desc[0].offset = 0;
397 break;
398 }
399 return 0;
400 }
401
402 /* notify an error as XRUN to the assigned PCM data substream */
notify_xrun(struct snd_usb_endpoint * ep)403 static void notify_xrun(struct snd_usb_endpoint *ep)
404 {
405 struct snd_usb_substream *data_subs;
406
407 data_subs = READ_ONCE(ep->data_subs);
408 if (data_subs && data_subs->pcm_substream)
409 snd_pcm_stop_xrun(data_subs->pcm_substream);
410 }
411
412 static struct snd_usb_packet_info *
next_packet_fifo_enqueue(struct snd_usb_endpoint * ep)413 next_packet_fifo_enqueue(struct snd_usb_endpoint *ep)
414 {
415 struct snd_usb_packet_info *p;
416
417 p = ep->next_packet + (ep->next_packet_head + ep->next_packet_queued) %
418 ARRAY_SIZE(ep->next_packet);
419 ep->next_packet_queued++;
420 return p;
421 }
422
423 static struct snd_usb_packet_info *
next_packet_fifo_dequeue(struct snd_usb_endpoint * ep)424 next_packet_fifo_dequeue(struct snd_usb_endpoint *ep)
425 {
426 struct snd_usb_packet_info *p;
427
428 p = ep->next_packet + ep->next_packet_head;
429 ep->next_packet_head++;
430 ep->next_packet_head %= ARRAY_SIZE(ep->next_packet);
431 ep->next_packet_queued--;
432 return p;
433 }
434
push_back_to_ready_list(struct snd_usb_endpoint * ep,struct snd_urb_ctx * ctx)435 static void push_back_to_ready_list(struct snd_usb_endpoint *ep,
436 struct snd_urb_ctx *ctx)
437 {
438 unsigned long flags;
439
440 spin_lock_irqsave(&ep->lock, flags);
441 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs);
442 spin_unlock_irqrestore(&ep->lock, flags);
443 }
444
445 /*
446 * Send output urbs that have been prepared previously. URBs are dequeued
447 * from ep->ready_playback_urbs and in case there aren't any available
448 * or there are no packets that have been prepared, this function does
449 * nothing.
450 *
451 * The reason why the functionality of sending and preparing URBs is separated
452 * is that host controllers don't guarantee the order in which they return
453 * inbound and outbound packets to their submitters.
454 *
455 * This function is used both for implicit feedback endpoints and in low-
456 * latency playback mode.
457 */
snd_usb_queue_pending_output_urbs(struct snd_usb_endpoint * ep,bool in_stream_lock)458 int snd_usb_queue_pending_output_urbs(struct snd_usb_endpoint *ep,
459 bool in_stream_lock)
460 {
461 bool implicit_fb = snd_usb_endpoint_implicit_feedback_sink(ep);
462
463 while (ep_state_running(ep)) {
464
465 unsigned long flags;
466 struct snd_usb_packet_info *packet;
467 struct snd_urb_ctx *ctx = NULL;
468 int err, i;
469
470 spin_lock_irqsave(&ep->lock, flags);
471 if ((!implicit_fb || ep->next_packet_queued > 0) &&
472 !list_empty(&ep->ready_playback_urbs)) {
473 /* take URB out of FIFO */
474 ctx = list_first_entry(&ep->ready_playback_urbs,
475 struct snd_urb_ctx, ready_list);
476 list_del_init(&ctx->ready_list);
477 if (implicit_fb)
478 packet = next_packet_fifo_dequeue(ep);
479 }
480 spin_unlock_irqrestore(&ep->lock, flags);
481
482 if (ctx == NULL)
483 break;
484
485 /* copy over the length information */
486 if (implicit_fb) {
487 for (i = 0; i < packet->packets; i++)
488 ctx->packet_size[i] = packet->packet_size[i];
489 }
490
491 /* call the data handler to fill in playback data */
492 err = prepare_outbound_urb(ep, ctx, in_stream_lock);
493 /* can be stopped during prepare callback */
494 if (unlikely(!ep_state_running(ep)))
495 break;
496 if (err < 0) {
497 /* push back to ready list again for -EAGAIN */
498 if (err == -EAGAIN) {
499 push_back_to_ready_list(ep, ctx);
500 break;
501 }
502
503 if (!in_stream_lock)
504 notify_xrun(ep);
505 return -EPIPE;
506 }
507
508 if (!atomic_read(&ep->chip->shutdown))
509 err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
510 else
511 err = -ENODEV;
512 if (err < 0) {
513 if (!atomic_read(&ep->chip->shutdown)) {
514 usb_audio_err(ep->chip,
515 "Unable to submit urb #%d: %d at %s\n",
516 ctx->index, err, __func__);
517 if (!in_stream_lock)
518 notify_xrun(ep);
519 }
520 return -EPIPE;
521 }
522
523 set_bit(ctx->index, &ep->active_mask);
524 atomic_inc(&ep->submitted_urbs);
525 }
526
527 return 0;
528 }
529
530 /*
531 * complete callback for urbs
532 */
snd_complete_urb(struct urb * urb)533 static void snd_complete_urb(struct urb *urb)
534 {
535 struct snd_urb_ctx *ctx = urb->context;
536 struct snd_usb_endpoint *ep = ctx->ep;
537 int err;
538
539 if (unlikely(urb->status == -ENOENT || /* unlinked */
540 urb->status == -ENODEV || /* device removed */
541 urb->status == -ECONNRESET || /* unlinked */
542 urb->status == -ESHUTDOWN)) /* device disabled */
543 goto exit_clear;
544 /* device disconnected */
545 if (unlikely(atomic_read(&ep->chip->shutdown)))
546 goto exit_clear;
547
548 if (unlikely(!ep_state_running(ep)))
549 goto exit_clear;
550
551 if (usb_pipeout(ep->pipe)) {
552 retire_outbound_urb(ep, ctx);
553 /* can be stopped during retire callback */
554 if (unlikely(!ep_state_running(ep)))
555 goto exit_clear;
556
557 /* in low-latency and implicit-feedback modes, push back the
558 * URB to ready list at first, then process as much as possible
559 */
560 if (ep->lowlatency_playback ||
561 snd_usb_endpoint_implicit_feedback_sink(ep)) {
562 push_back_to_ready_list(ep, ctx);
563 clear_bit(ctx->index, &ep->active_mask);
564 snd_usb_queue_pending_output_urbs(ep, false);
565 atomic_dec(&ep->submitted_urbs); /* decrement at last */
566 return;
567 }
568
569 /* in non-lowlatency mode, no error handling for prepare */
570 prepare_outbound_urb(ep, ctx, false);
571 /* can be stopped during prepare callback */
572 if (unlikely(!ep_state_running(ep)))
573 goto exit_clear;
574 } else {
575 retire_inbound_urb(ep, ctx);
576 /* can be stopped during retire callback */
577 if (unlikely(!ep_state_running(ep)))
578 goto exit_clear;
579
580 prepare_inbound_urb(ep, ctx);
581 }
582
583 if (!atomic_read(&ep->chip->shutdown))
584 err = usb_submit_urb(urb, GFP_ATOMIC);
585 else
586 err = -ENODEV;
587 if (err == 0)
588 return;
589
590 if (!atomic_read(&ep->chip->shutdown)) {
591 usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err);
592 notify_xrun(ep);
593 }
594
595 exit_clear:
596 clear_bit(ctx->index, &ep->active_mask);
597 atomic_dec(&ep->submitted_urbs);
598 }
599
600 /*
601 * Find or create a refcount object for the given interface
602 *
603 * The objects are released altogether in snd_usb_endpoint_free_all()
604 */
605 static struct snd_usb_iface_ref *
iface_ref_find(struct snd_usb_audio * chip,int iface)606 iface_ref_find(struct snd_usb_audio *chip, int iface)
607 {
608 struct snd_usb_iface_ref *ip;
609
610 list_for_each_entry(ip, &chip->iface_ref_list, list)
611 if (ip->iface == iface)
612 return ip;
613
614 ip = kzalloc(sizeof(*ip), GFP_KERNEL);
615 if (!ip)
616 return NULL;
617 ip->iface = iface;
618 list_add_tail(&ip->list, &chip->iface_ref_list);
619 return ip;
620 }
621
622 /* Similarly, a refcount object for clock */
623 static struct snd_usb_clock_ref *
clock_ref_find(struct snd_usb_audio * chip,int clock)624 clock_ref_find(struct snd_usb_audio *chip, int clock)
625 {
626 struct snd_usb_clock_ref *ref;
627
628 list_for_each_entry(ref, &chip->clock_ref_list, list)
629 if (ref->clock == clock)
630 return ref;
631
632 ref = kzalloc(sizeof(*ref), GFP_KERNEL);
633 if (!ref)
634 return NULL;
635 ref->clock = clock;
636 atomic_set(&ref->locked, 0);
637 list_add_tail(&ref->list, &chip->clock_ref_list);
638 return ref;
639 }
640
641 /*
642 * Get the existing endpoint object corresponding EP
643 * Returns NULL if not present.
644 */
645 struct snd_usb_endpoint *
snd_usb_get_endpoint(struct snd_usb_audio * chip,int ep_num)646 snd_usb_get_endpoint(struct snd_usb_audio *chip, int ep_num)
647 {
648 struct snd_usb_endpoint *ep;
649
650 list_for_each_entry(ep, &chip->ep_list, list) {
651 if (ep->ep_num == ep_num)
652 return ep;
653 }
654
655 return NULL;
656 }
657
658 #define ep_type_name(type) \
659 (type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync")
660
661 /**
662 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip
663 *
664 * @chip: The chip
665 * @ep_num: The number of the endpoint to use
666 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC
667 *
668 * If the requested endpoint has not been added to the given chip before,
669 * a new instance is created.
670 *
671 * Returns zero on success or a negative error code.
672 *
673 * New endpoints will be added to chip->ep_list and freed by
674 * calling snd_usb_endpoint_free_all().
675 *
676 * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that
677 * bNumEndpoints > 1 beforehand.
678 */
snd_usb_add_endpoint(struct snd_usb_audio * chip,int ep_num,int type)679 int snd_usb_add_endpoint(struct snd_usb_audio *chip, int ep_num, int type)
680 {
681 struct snd_usb_endpoint *ep;
682 bool is_playback;
683
684 ep = snd_usb_get_endpoint(chip, ep_num);
685 if (ep)
686 return 0;
687
688 usb_audio_dbg(chip, "Creating new %s endpoint #%x\n",
689 ep_type_name(type),
690 ep_num);
691 ep = kzalloc(sizeof(*ep), GFP_KERNEL);
692 if (!ep)
693 return -ENOMEM;
694
695 ep->chip = chip;
696 spin_lock_init(&ep->lock);
697 ep->type = type;
698 ep->ep_num = ep_num;
699 INIT_LIST_HEAD(&ep->ready_playback_urbs);
700 atomic_set(&ep->submitted_urbs, 0);
701
702 is_playback = ((ep_num & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT);
703 ep_num &= USB_ENDPOINT_NUMBER_MASK;
704 if (is_playback)
705 ep->pipe = usb_sndisocpipe(chip->dev, ep_num);
706 else
707 ep->pipe = usb_rcvisocpipe(chip->dev, ep_num);
708
709 list_add_tail(&ep->list, &chip->ep_list);
710 return 0;
711 }
712
713 /* Set up syncinterval and maxsyncsize for a sync EP */
endpoint_set_syncinterval(struct snd_usb_audio * chip,struct snd_usb_endpoint * ep)714 static void endpoint_set_syncinterval(struct snd_usb_audio *chip,
715 struct snd_usb_endpoint *ep)
716 {
717 struct usb_host_interface *alts;
718 struct usb_endpoint_descriptor *desc;
719
720 alts = snd_usb_get_host_interface(chip, ep->iface, ep->altsetting);
721 if (!alts)
722 return;
723
724 desc = get_endpoint(alts, ep->ep_idx);
725 if (desc->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
726 desc->bRefresh >= 1 && desc->bRefresh <= 9)
727 ep->syncinterval = desc->bRefresh;
728 else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL)
729 ep->syncinterval = 1;
730 else if (desc->bInterval >= 1 && desc->bInterval <= 16)
731 ep->syncinterval = desc->bInterval - 1;
732 else
733 ep->syncinterval = 3;
734
735 ep->syncmaxsize = le16_to_cpu(desc->wMaxPacketSize);
736 }
737
endpoint_compatible(struct snd_usb_endpoint * ep,const struct audioformat * fp,const struct snd_pcm_hw_params * params)738 static bool endpoint_compatible(struct snd_usb_endpoint *ep,
739 const struct audioformat *fp,
740 const struct snd_pcm_hw_params *params)
741 {
742 if (!ep->opened)
743 return false;
744 if (ep->cur_audiofmt != fp)
745 return false;
746 if (ep->cur_rate != params_rate(params) ||
747 ep->cur_format != params_format(params) ||
748 ep->cur_period_frames != params_period_size(params) ||
749 ep->cur_buffer_periods != params_periods(params))
750 return false;
751 return true;
752 }
753
754 /*
755 * Check whether the given fp and hw params are compatible with the current
756 * setup of the target EP for implicit feedback sync
757 */
snd_usb_endpoint_compatible(struct snd_usb_audio * chip,struct snd_usb_endpoint * ep,const struct audioformat * fp,const struct snd_pcm_hw_params * params)758 bool snd_usb_endpoint_compatible(struct snd_usb_audio *chip,
759 struct snd_usb_endpoint *ep,
760 const struct audioformat *fp,
761 const struct snd_pcm_hw_params *params)
762 {
763 bool ret;
764
765 mutex_lock(&chip->mutex);
766 ret = endpoint_compatible(ep, fp, params);
767 mutex_unlock(&chip->mutex);
768 return ret;
769 }
770
771 /*
772 * snd_usb_endpoint_open: Open the endpoint
773 *
774 * Called from hw_params to assign the endpoint to the substream.
775 * It's reference-counted, and only the first opener is allowed to set up
776 * arbitrary parameters. The later opener must be compatible with the
777 * former opened parameters.
778 * The endpoint needs to be closed via snd_usb_endpoint_close() later.
779 *
780 * Note that this function doesn't configure the endpoint. The substream
781 * needs to set it up later via snd_usb_endpoint_set_params() and
782 * snd_usb_endpoint_prepare().
783 */
784 struct snd_usb_endpoint *
snd_usb_endpoint_open(struct snd_usb_audio * chip,const struct audioformat * fp,const struct snd_pcm_hw_params * params,bool is_sync_ep,bool fixed_rate)785 snd_usb_endpoint_open(struct snd_usb_audio *chip,
786 const struct audioformat *fp,
787 const struct snd_pcm_hw_params *params,
788 bool is_sync_ep,
789 bool fixed_rate)
790 {
791 struct snd_usb_endpoint *ep;
792 int ep_num = is_sync_ep ? fp->sync_ep : fp->endpoint;
793
794 mutex_lock(&chip->mutex);
795 ep = snd_usb_get_endpoint(chip, ep_num);
796 if (!ep) {
797 usb_audio_err(chip, "Cannot find EP 0x%x to open\n", ep_num);
798 goto unlock;
799 }
800
801 if (!ep->opened) {
802 if (is_sync_ep) {
803 ep->iface = fp->sync_iface;
804 ep->altsetting = fp->sync_altsetting;
805 ep->ep_idx = fp->sync_ep_idx;
806 } else {
807 ep->iface = fp->iface;
808 ep->altsetting = fp->altsetting;
809 ep->ep_idx = fp->ep_idx;
810 }
811 usb_audio_dbg(chip, "Open EP 0x%x, iface=%d:%d, idx=%d\n",
812 ep_num, ep->iface, ep->altsetting, ep->ep_idx);
813
814 ep->iface_ref = iface_ref_find(chip, ep->iface);
815 if (!ep->iface_ref) {
816 ep = NULL;
817 goto unlock;
818 }
819
820 if (fp->protocol != UAC_VERSION_1) {
821 ep->clock_ref = clock_ref_find(chip, fp->clock);
822 if (!ep->clock_ref) {
823 ep = NULL;
824 goto unlock;
825 }
826 ep->clock_ref->opened++;
827 }
828
829 ep->cur_audiofmt = fp;
830 ep->cur_channels = fp->channels;
831 ep->cur_rate = params_rate(params);
832 ep->cur_format = params_format(params);
833 ep->cur_frame_bytes = snd_pcm_format_physical_width(ep->cur_format) *
834 ep->cur_channels / 8;
835 ep->cur_period_frames = params_period_size(params);
836 ep->cur_period_bytes = ep->cur_period_frames * ep->cur_frame_bytes;
837 ep->cur_buffer_periods = params_periods(params);
838
839 if (ep->type == SND_USB_ENDPOINT_TYPE_SYNC)
840 endpoint_set_syncinterval(chip, ep);
841
842 ep->implicit_fb_sync = fp->implicit_fb;
843 ep->need_setup = true;
844 ep->need_prepare = true;
845 ep->fixed_rate = fixed_rate;
846
847 usb_audio_dbg(chip, " channels=%d, rate=%d, format=%s, period_bytes=%d, periods=%d, implicit_fb=%d\n",
848 ep->cur_channels, ep->cur_rate,
849 snd_pcm_format_name(ep->cur_format),
850 ep->cur_period_bytes, ep->cur_buffer_periods,
851 ep->implicit_fb_sync);
852
853 } else {
854 if (WARN_ON(!ep->iface_ref)) {
855 ep = NULL;
856 goto unlock;
857 }
858
859 if (!endpoint_compatible(ep, fp, params)) {
860 usb_audio_err(chip, "Incompatible EP setup for 0x%x\n",
861 ep_num);
862 ep = NULL;
863 goto unlock;
864 }
865
866 usb_audio_dbg(chip, "Reopened EP 0x%x (count %d)\n",
867 ep_num, ep->opened);
868 }
869
870 if (!ep->iface_ref->opened++)
871 ep->iface_ref->need_setup = true;
872
873 ep->opened++;
874
875 unlock:
876 mutex_unlock(&chip->mutex);
877 return ep;
878 }
879
880 /*
881 * snd_usb_endpoint_set_sync: Link data and sync endpoints
882 *
883 * Pass NULL to sync_ep to unlink again
884 */
snd_usb_endpoint_set_sync(struct snd_usb_audio * chip,struct snd_usb_endpoint * data_ep,struct snd_usb_endpoint * sync_ep)885 void snd_usb_endpoint_set_sync(struct snd_usb_audio *chip,
886 struct snd_usb_endpoint *data_ep,
887 struct snd_usb_endpoint *sync_ep)
888 {
889 data_ep->sync_source = sync_ep;
890 }
891
892 /*
893 * Set data endpoint callbacks and the assigned data stream
894 *
895 * Called at PCM trigger and cleanups.
896 * Pass NULL to deactivate each callback.
897 */
snd_usb_endpoint_set_callback(struct snd_usb_endpoint * ep,int (* prepare)(struct snd_usb_substream * subs,struct urb * urb,bool in_stream_lock),void (* retire)(struct snd_usb_substream * subs,struct urb * urb),struct snd_usb_substream * data_subs)898 void snd_usb_endpoint_set_callback(struct snd_usb_endpoint *ep,
899 int (*prepare)(struct snd_usb_substream *subs,
900 struct urb *urb,
901 bool in_stream_lock),
902 void (*retire)(struct snd_usb_substream *subs,
903 struct urb *urb),
904 struct snd_usb_substream *data_subs)
905 {
906 ep->prepare_data_urb = prepare;
907 ep->retire_data_urb = retire;
908 if (data_subs)
909 ep->lowlatency_playback = data_subs->lowlatency_playback;
910 else
911 ep->lowlatency_playback = false;
912 WRITE_ONCE(ep->data_subs, data_subs);
913 }
914
endpoint_set_interface(struct snd_usb_audio * chip,struct snd_usb_endpoint * ep,bool set)915 static int endpoint_set_interface(struct snd_usb_audio *chip,
916 struct snd_usb_endpoint *ep,
917 bool set)
918 {
919 int altset = set ? ep->altsetting : 0;
920 int err;
921
922 if (ep->iface_ref->altset == altset)
923 return 0;
924 /* already disconnected? */
925 if (unlikely(atomic_read(&chip->shutdown)))
926 return -ENODEV;
927
928 usb_audio_dbg(chip, "Setting usb interface %d:%d for EP 0x%x\n",
929 ep->iface, altset, ep->ep_num);
930 err = usb_set_interface(chip->dev, ep->iface, altset);
931 if (err < 0) {
932 usb_audio_err_ratelimited(
933 chip, "%d:%d: usb_set_interface failed (%d)\n",
934 ep->iface, altset, err);
935 return err;
936 }
937
938 if (chip->quirk_flags & QUIRK_FLAG_IFACE_DELAY)
939 msleep(50);
940 ep->iface_ref->altset = altset;
941 return 0;
942 }
943
944 /*
945 * snd_usb_endpoint_close: Close the endpoint
946 *
947 * Unreference the already opened endpoint via snd_usb_endpoint_open().
948 */
snd_usb_endpoint_close(struct snd_usb_audio * chip,struct snd_usb_endpoint * ep)949 void snd_usb_endpoint_close(struct snd_usb_audio *chip,
950 struct snd_usb_endpoint *ep)
951 {
952 mutex_lock(&chip->mutex);
953 usb_audio_dbg(chip, "Closing EP 0x%x (count %d)\n",
954 ep->ep_num, ep->opened);
955
956 if (!--ep->iface_ref->opened &&
957 !(chip->quirk_flags & QUIRK_FLAG_IFACE_SKIP_CLOSE))
958 endpoint_set_interface(chip, ep, false);
959
960 if (!--ep->opened) {
961 if (ep->clock_ref) {
962 if (!--ep->clock_ref->opened)
963 ep->clock_ref->rate = 0;
964 }
965 ep->iface = 0;
966 ep->altsetting = 0;
967 ep->cur_audiofmt = NULL;
968 ep->cur_rate = 0;
969 ep->iface_ref = NULL;
970 ep->clock_ref = NULL;
971 usb_audio_dbg(chip, "EP 0x%x closed\n", ep->ep_num);
972 }
973 mutex_unlock(&chip->mutex);
974 }
975
976 /* Prepare for suspening EP, called from the main suspend handler */
snd_usb_endpoint_suspend(struct snd_usb_endpoint * ep)977 void snd_usb_endpoint_suspend(struct snd_usb_endpoint *ep)
978 {
979 ep->need_prepare = true;
980 if (ep->iface_ref)
981 ep->iface_ref->need_setup = true;
982 if (ep->clock_ref)
983 ep->clock_ref->rate = 0;
984 }
985
986 /*
987 * wait until all urbs are processed.
988 */
wait_clear_urbs(struct snd_usb_endpoint * ep)989 static int wait_clear_urbs(struct snd_usb_endpoint *ep)
990 {
991 unsigned long end_time = jiffies + msecs_to_jiffies(1000);
992 int alive;
993
994 if (atomic_read(&ep->state) != EP_STATE_STOPPING)
995 return 0;
996
997 do {
998 alive = atomic_read(&ep->submitted_urbs);
999 if (!alive)
1000 break;
1001
1002 schedule_timeout_uninterruptible(1);
1003 } while (time_before(jiffies, end_time));
1004
1005 if (alive)
1006 usb_audio_err(ep->chip,
1007 "timeout: still %d active urbs on EP #%x\n",
1008 alive, ep->ep_num);
1009
1010 if (ep_state_update(ep, EP_STATE_STOPPING, EP_STATE_STOPPED)) {
1011 ep->sync_sink = NULL;
1012 snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
1013 }
1014
1015 return 0;
1016 }
1017
1018 /* sync the pending stop operation;
1019 * this function itself doesn't trigger the stop operation
1020 */
snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint * ep)1021 void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
1022 {
1023 if (ep)
1024 wait_clear_urbs(ep);
1025 }
1026
1027 /*
1028 * Stop active urbs
1029 *
1030 * This function moves the EP to STOPPING state if it's being RUNNING.
1031 */
stop_urbs(struct snd_usb_endpoint * ep,bool force,bool keep_pending)1032 static int stop_urbs(struct snd_usb_endpoint *ep, bool force, bool keep_pending)
1033 {
1034 unsigned int i;
1035 unsigned long flags;
1036
1037 if (!force && atomic_read(&ep->running))
1038 return -EBUSY;
1039
1040 if (!ep_state_update(ep, EP_STATE_RUNNING, EP_STATE_STOPPING))
1041 return 0;
1042
1043 spin_lock_irqsave(&ep->lock, flags);
1044 INIT_LIST_HEAD(&ep->ready_playback_urbs);
1045 ep->next_packet_head = 0;
1046 ep->next_packet_queued = 0;
1047 spin_unlock_irqrestore(&ep->lock, flags);
1048
1049 if (keep_pending)
1050 return 0;
1051
1052 for (i = 0; i < ep->nurbs; i++) {
1053 if (test_bit(i, &ep->active_mask)) {
1054 if (!test_and_set_bit(i, &ep->unlink_mask)) {
1055 struct urb *u = ep->urb[i].urb;
1056 usb_unlink_urb(u);
1057 }
1058 }
1059 }
1060
1061 return 0;
1062 }
1063
1064 /*
1065 * release an endpoint's urbs
1066 */
release_urbs(struct snd_usb_endpoint * ep,bool force)1067 static int release_urbs(struct snd_usb_endpoint *ep, bool force)
1068 {
1069 int i, err;
1070
1071 /* route incoming urbs to nirvana */
1072 snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL);
1073
1074 /* stop and unlink urbs */
1075 err = stop_urbs(ep, force, false);
1076 if (err)
1077 return err;
1078
1079 wait_clear_urbs(ep);
1080
1081 for (i = 0; i < ep->nurbs; i++)
1082 release_urb_ctx(&ep->urb[i]);
1083
1084 usb_free_coherent(ep->chip->dev, SYNC_URBS * 4,
1085 ep->syncbuf, ep->sync_dma);
1086
1087 ep->syncbuf = NULL;
1088 ep->nurbs = 0;
1089 return 0;
1090 }
1091
1092 /*
1093 * configure a data endpoint
1094 */
data_ep_set_params(struct snd_usb_endpoint * ep)1095 static int data_ep_set_params(struct snd_usb_endpoint *ep)
1096 {
1097 struct snd_usb_audio *chip = ep->chip;
1098 unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb;
1099 unsigned int max_packs_per_period, urbs_per_period, urb_packs;
1100 unsigned int max_urbs, i;
1101 const struct audioformat *fmt = ep->cur_audiofmt;
1102 int frame_bits = ep->cur_frame_bytes * 8;
1103 int tx_length_quirk = (has_tx_length_quirk(chip) &&
1104 usb_pipeout(ep->pipe));
1105
1106 usb_audio_dbg(chip, "Setting params for data EP 0x%x, pipe 0x%x\n",
1107 ep->ep_num, ep->pipe);
1108
1109 if (ep->cur_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) {
1110 /*
1111 * When operating in DSD DOP mode, the size of a sample frame
1112 * in hardware differs from the actual physical format width
1113 * because we need to make room for the DOP markers.
1114 */
1115 frame_bits += ep->cur_channels << 3;
1116 }
1117
1118 ep->datainterval = fmt->datainterval;
1119 ep->stride = frame_bits >> 3;
1120
1121 switch (ep->cur_format) {
1122 case SNDRV_PCM_FORMAT_U8:
1123 ep->silence_value = 0x80;
1124 break;
1125 case SNDRV_PCM_FORMAT_DSD_U8:
1126 case SNDRV_PCM_FORMAT_DSD_U16_LE:
1127 case SNDRV_PCM_FORMAT_DSD_U32_LE:
1128 case SNDRV_PCM_FORMAT_DSD_U16_BE:
1129 case SNDRV_PCM_FORMAT_DSD_U32_BE:
1130 ep->silence_value = 0x69;
1131 break;
1132 default:
1133 ep->silence_value = 0;
1134 }
1135
1136 /* assume max. frequency is 50% higher than nominal */
1137 ep->freqmax = ep->freqn + (ep->freqn >> 1);
1138 /* Round up freqmax to nearest integer in order to calculate maximum
1139 * packet size, which must represent a whole number of frames.
1140 * This is accomplished by adding 0x0.ffff before converting the
1141 * Q16.16 format into integer.
1142 * In order to accurately calculate the maximum packet size when
1143 * the data interval is more than 1 (i.e. ep->datainterval > 0),
1144 * multiply by the data interval prior to rounding. For instance,
1145 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
1146 * frames with a data interval of 1, but 11 (10.25) frames with a
1147 * data interval of 2.
1148 * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the
1149 * maximum datainterval value of 3, at USB full speed, higher for
1150 * USB high speed, noting that ep->freqmax is in units of
1151 * frames per packet in Q16.16 format.)
1152 */
1153 maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) *
1154 (frame_bits >> 3);
1155 if (tx_length_quirk)
1156 maxsize += sizeof(__le32); /* Space for length descriptor */
1157 /* but wMaxPacketSize might reduce this */
1158 if (ep->maxpacksize && ep->maxpacksize < maxsize) {
1159 /* whatever fits into a max. size packet */
1160 unsigned int data_maxsize = maxsize = ep->maxpacksize;
1161
1162 if (tx_length_quirk)
1163 /* Need to remove the length descriptor to calc freq */
1164 data_maxsize -= sizeof(__le32);
1165 ep->freqmax = (data_maxsize / (frame_bits >> 3))
1166 << (16 - ep->datainterval);
1167 }
1168
1169 if (ep->fill_max)
1170 ep->curpacksize = ep->maxpacksize;
1171 else
1172 ep->curpacksize = maxsize;
1173
1174 if (snd_usb_get_speed(chip->dev) != USB_SPEED_FULL) {
1175 packs_per_ms = 8 >> ep->datainterval;
1176 max_packs_per_urb = MAX_PACKS_HS;
1177 } else {
1178 packs_per_ms = 1;
1179 max_packs_per_urb = MAX_PACKS;
1180 }
1181 if (ep->sync_source && !ep->implicit_fb_sync)
1182 max_packs_per_urb = min(max_packs_per_urb,
1183 1U << ep->sync_source->syncinterval);
1184 max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval);
1185
1186 /*
1187 * Capture endpoints need to use small URBs because there's no way
1188 * to tell in advance where the next period will end, and we don't
1189 * want the next URB to complete much after the period ends.
1190 *
1191 * Playback endpoints with implicit sync much use the same parameters
1192 * as their corresponding capture endpoint.
1193 */
1194 if (usb_pipein(ep->pipe) || ep->implicit_fb_sync) {
1195
1196 /* make capture URBs <= 1 ms and smaller than a period */
1197 urb_packs = min(max_packs_per_urb, packs_per_ms);
1198 while (urb_packs > 1 && urb_packs * maxsize >= ep->cur_period_bytes)
1199 urb_packs >>= 1;
1200 ep->nurbs = MAX_URBS;
1201
1202 /*
1203 * Playback endpoints without implicit sync are adjusted so that
1204 * a period fits as evenly as possible in the smallest number of
1205 * URBs. The total number of URBs is adjusted to the size of the
1206 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits.
1207 */
1208 } else {
1209 /* determine how small a packet can be */
1210 minsize = (ep->freqn >> (16 - ep->datainterval)) *
1211 (frame_bits >> 3);
1212 /* with sync from device, assume it can be 12% lower */
1213 if (ep->sync_source)
1214 minsize -= minsize >> 3;
1215 minsize = max(minsize, 1u);
1216
1217 /* how many packets will contain an entire ALSA period? */
1218 max_packs_per_period = DIV_ROUND_UP(ep->cur_period_bytes, minsize);
1219
1220 /* how many URBs will contain a period? */
1221 urbs_per_period = DIV_ROUND_UP(max_packs_per_period,
1222 max_packs_per_urb);
1223 /* how many packets are needed in each URB? */
1224 urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period);
1225
1226 /* limit the number of frames in a single URB */
1227 ep->max_urb_frames = DIV_ROUND_UP(ep->cur_period_frames,
1228 urbs_per_period);
1229
1230 /* try to use enough URBs to contain an entire ALSA buffer */
1231 max_urbs = min((unsigned) MAX_URBS,
1232 MAX_QUEUE * packs_per_ms / urb_packs);
1233 ep->nurbs = min(max_urbs, urbs_per_period * ep->cur_buffer_periods);
1234 }
1235
1236 /* allocate and initialize data urbs */
1237 for (i = 0; i < ep->nurbs; i++) {
1238 struct snd_urb_ctx *u = &ep->urb[i];
1239 u->index = i;
1240 u->ep = ep;
1241 u->packets = urb_packs;
1242 u->buffer_size = maxsize * u->packets;
1243
1244 if (fmt->fmt_type == UAC_FORMAT_TYPE_II)
1245 u->packets++; /* for transfer delimiter */
1246 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
1247 if (!u->urb)
1248 goto out_of_memory;
1249
1250 u->urb->transfer_buffer =
1251 usb_alloc_coherent(chip->dev, u->buffer_size,
1252 GFP_KERNEL, &u->urb->transfer_dma);
1253 if (!u->urb->transfer_buffer)
1254 goto out_of_memory;
1255 u->urb->pipe = ep->pipe;
1256 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
1257 u->urb->interval = 1 << ep->datainterval;
1258 u->urb->context = u;
1259 u->urb->complete = snd_complete_urb;
1260 INIT_LIST_HEAD(&u->ready_list);
1261 }
1262
1263 return 0;
1264
1265 out_of_memory:
1266 release_urbs(ep, false);
1267 return -ENOMEM;
1268 }
1269
1270 /*
1271 * configure a sync endpoint
1272 */
sync_ep_set_params(struct snd_usb_endpoint * ep)1273 static int sync_ep_set_params(struct snd_usb_endpoint *ep)
1274 {
1275 struct snd_usb_audio *chip = ep->chip;
1276 int i;
1277
1278 usb_audio_dbg(chip, "Setting params for sync EP 0x%x, pipe 0x%x\n",
1279 ep->ep_num, ep->pipe);
1280
1281 ep->syncbuf = usb_alloc_coherent(chip->dev, SYNC_URBS * 4,
1282 GFP_KERNEL, &ep->sync_dma);
1283 if (!ep->syncbuf)
1284 return -ENOMEM;
1285
1286 ep->nurbs = SYNC_URBS;
1287 for (i = 0; i < SYNC_URBS; i++) {
1288 struct snd_urb_ctx *u = &ep->urb[i];
1289 u->index = i;
1290 u->ep = ep;
1291 u->packets = 1;
1292 u->urb = usb_alloc_urb(1, GFP_KERNEL);
1293 if (!u->urb)
1294 goto out_of_memory;
1295 u->urb->transfer_buffer = ep->syncbuf + i * 4;
1296 u->urb->transfer_dma = ep->sync_dma + i * 4;
1297 u->urb->transfer_buffer_length = 4;
1298 u->urb->pipe = ep->pipe;
1299 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
1300 u->urb->number_of_packets = 1;
1301 u->urb->interval = 1 << ep->syncinterval;
1302 u->urb->context = u;
1303 u->urb->complete = snd_complete_urb;
1304 }
1305
1306 return 0;
1307
1308 out_of_memory:
1309 release_urbs(ep, false);
1310 return -ENOMEM;
1311 }
1312
1313 /* update the rate of the referred clock; return the actual rate */
update_clock_ref_rate(struct snd_usb_audio * chip,struct snd_usb_endpoint * ep)1314 static int update_clock_ref_rate(struct snd_usb_audio *chip,
1315 struct snd_usb_endpoint *ep)
1316 {
1317 struct snd_usb_clock_ref *clock = ep->clock_ref;
1318 int rate = ep->cur_rate;
1319
1320 if (!clock || clock->rate == rate)
1321 return rate;
1322 if (clock->rate) {
1323 if (atomic_read(&clock->locked))
1324 return clock->rate;
1325 if (clock->rate != rate) {
1326 usb_audio_err(chip, "Mismatched sample rate %d vs %d for EP 0x%x\n",
1327 clock->rate, rate, ep->ep_num);
1328 return clock->rate;
1329 }
1330 }
1331 clock->rate = rate;
1332 clock->need_setup = true;
1333 return rate;
1334 }
1335
1336 /*
1337 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
1338 *
1339 * It's called either from hw_params callback.
1340 * Determine the number of URBs to be used on this endpoint.
1341 * An endpoint must be configured before it can be started.
1342 * An endpoint that is already running can not be reconfigured.
1343 */
snd_usb_endpoint_set_params(struct snd_usb_audio * chip,struct snd_usb_endpoint * ep)1344 int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
1345 struct snd_usb_endpoint *ep)
1346 {
1347 const struct audioformat *fmt = ep->cur_audiofmt;
1348 int err = 0;
1349
1350 mutex_lock(&chip->mutex);
1351 if (!ep->need_setup)
1352 goto unlock;
1353
1354 /* release old buffers, if any */
1355 err = release_urbs(ep, false);
1356 if (err < 0)
1357 goto unlock;
1358
1359 ep->datainterval = fmt->datainterval;
1360 ep->maxpacksize = fmt->maxpacksize;
1361 ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX);
1362
1363 if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL) {
1364 ep->freqn = get_usb_full_speed_rate(ep->cur_rate);
1365 ep->pps = 1000 >> ep->datainterval;
1366 } else {
1367 ep->freqn = get_usb_high_speed_rate(ep->cur_rate);
1368 ep->pps = 8000 >> ep->datainterval;
1369 }
1370
1371 ep->sample_rem = ep->cur_rate % ep->pps;
1372 ep->packsize[0] = ep->cur_rate / ep->pps;
1373 ep->packsize[1] = (ep->cur_rate + (ep->pps - 1)) / ep->pps;
1374
1375 /* calculate the frequency in 16.16 format */
1376 ep->freqm = ep->freqn;
1377 ep->freqshift = INT_MIN;
1378
1379 ep->phase = 0;
1380
1381 switch (ep->type) {
1382 case SND_USB_ENDPOINT_TYPE_DATA:
1383 err = data_ep_set_params(ep);
1384 break;
1385 case SND_USB_ENDPOINT_TYPE_SYNC:
1386 err = sync_ep_set_params(ep);
1387 break;
1388 default:
1389 err = -EINVAL;
1390 }
1391
1392 usb_audio_dbg(chip, "Set up %d URBS, ret=%d\n", ep->nurbs, err);
1393
1394 if (err < 0)
1395 goto unlock;
1396
1397 /* some unit conversions in runtime */
1398 ep->maxframesize = ep->maxpacksize / ep->cur_frame_bytes;
1399 ep->curframesize = ep->curpacksize / ep->cur_frame_bytes;
1400
1401 err = update_clock_ref_rate(chip, ep);
1402 if (err >= 0) {
1403 ep->need_setup = false;
1404 err = 0;
1405 }
1406
1407 unlock:
1408 mutex_unlock(&chip->mutex);
1409 return err;
1410 }
1411
init_sample_rate(struct snd_usb_audio * chip,struct snd_usb_endpoint * ep)1412 static int init_sample_rate(struct snd_usb_audio *chip,
1413 struct snd_usb_endpoint *ep)
1414 {
1415 struct snd_usb_clock_ref *clock = ep->clock_ref;
1416 int rate, err;
1417
1418 rate = update_clock_ref_rate(chip, ep);
1419 if (rate < 0)
1420 return rate;
1421 if (clock && !clock->need_setup)
1422 return 0;
1423
1424 if (!ep->fixed_rate) {
1425 err = snd_usb_init_sample_rate(chip, ep->cur_audiofmt, rate);
1426 if (err < 0) {
1427 if (clock)
1428 clock->rate = 0; /* reset rate */
1429 return err;
1430 }
1431 }
1432
1433 if (clock)
1434 clock->need_setup = false;
1435 return 0;
1436 }
1437
1438 /*
1439 * snd_usb_endpoint_prepare: Prepare the endpoint
1440 *
1441 * This function sets up the EP to be fully usable state.
1442 * It's called either from prepare callback.
1443 * The function checks need_setup flag, and performs nothing unless needed,
1444 * so it's safe to call this multiple times.
1445 *
1446 * This returns zero if unchanged, 1 if the configuration has changed,
1447 * or a negative error code.
1448 */
snd_usb_endpoint_prepare(struct snd_usb_audio * chip,struct snd_usb_endpoint * ep)1449 int snd_usb_endpoint_prepare(struct snd_usb_audio *chip,
1450 struct snd_usb_endpoint *ep)
1451 {
1452 bool iface_first;
1453 int err = 0;
1454
1455 mutex_lock(&chip->mutex);
1456 if (WARN_ON(!ep->iface_ref))
1457 goto unlock;
1458 if (!ep->need_prepare)
1459 goto unlock;
1460
1461 /* If the interface has been already set up, just set EP parameters */
1462 if (!ep->iface_ref->need_setup) {
1463 /* sample rate setup of UAC1 is per endpoint, and we need
1464 * to update at each EP configuration
1465 */
1466 if (ep->cur_audiofmt->protocol == UAC_VERSION_1) {
1467 err = init_sample_rate(chip, ep);
1468 if (err < 0)
1469 goto unlock;
1470 }
1471 goto done;
1472 }
1473
1474 /* Need to deselect altsetting at first */
1475 endpoint_set_interface(chip, ep, false);
1476
1477 /* Some UAC1 devices (e.g. Yamaha THR10) need the host interface
1478 * to be set up before parameter setups
1479 */
1480 iface_first = ep->cur_audiofmt->protocol == UAC_VERSION_1;
1481 /* Workaround for devices that require the interface setup at first like UAC1 */
1482 if (chip->quirk_flags & QUIRK_FLAG_SET_IFACE_FIRST)
1483 iface_first = true;
1484 if (iface_first) {
1485 err = endpoint_set_interface(chip, ep, true);
1486 if (err < 0)
1487 goto unlock;
1488 }
1489
1490 err = snd_usb_init_pitch(chip, ep->cur_audiofmt);
1491 if (err < 0)
1492 goto unlock;
1493
1494 err = init_sample_rate(chip, ep);
1495 if (err < 0)
1496 goto unlock;
1497
1498 err = snd_usb_select_mode_quirk(chip, ep->cur_audiofmt);
1499 if (err < 0)
1500 goto unlock;
1501
1502 /* for UAC2/3, enable the interface altset here at last */
1503 if (!iface_first) {
1504 err = endpoint_set_interface(chip, ep, true);
1505 if (err < 0)
1506 goto unlock;
1507 }
1508
1509 ep->iface_ref->need_setup = false;
1510
1511 done:
1512 ep->need_prepare = false;
1513 err = 1;
1514
1515 unlock:
1516 mutex_unlock(&chip->mutex);
1517 return err;
1518 }
1519
1520 /* get the current rate set to the given clock by any endpoint */
snd_usb_endpoint_get_clock_rate(struct snd_usb_audio * chip,int clock)1521 int snd_usb_endpoint_get_clock_rate(struct snd_usb_audio *chip, int clock)
1522 {
1523 struct snd_usb_clock_ref *ref;
1524 int rate = 0;
1525
1526 if (!clock)
1527 return 0;
1528 mutex_lock(&chip->mutex);
1529 list_for_each_entry(ref, &chip->clock_ref_list, list) {
1530 if (ref->clock == clock) {
1531 rate = ref->rate;
1532 break;
1533 }
1534 }
1535 mutex_unlock(&chip->mutex);
1536 return rate;
1537 }
1538
1539 /**
1540 * snd_usb_endpoint_start: start an snd_usb_endpoint
1541 *
1542 * @ep: the endpoint to start
1543 *
1544 * A call to this function will increment the running count of the endpoint.
1545 * In case it is not already running, the URBs for this endpoint will be
1546 * submitted. Otherwise, this function does nothing.
1547 *
1548 * Must be balanced to calls of snd_usb_endpoint_stop().
1549 *
1550 * Returns an error if the URB submission failed, 0 in all other cases.
1551 */
snd_usb_endpoint_start(struct snd_usb_endpoint * ep)1552 int snd_usb_endpoint_start(struct snd_usb_endpoint *ep)
1553 {
1554 bool is_playback = usb_pipeout(ep->pipe);
1555 int err;
1556 unsigned int i;
1557
1558 if (atomic_read(&ep->chip->shutdown))
1559 return -EBADFD;
1560
1561 if (ep->sync_source)
1562 WRITE_ONCE(ep->sync_source->sync_sink, ep);
1563
1564 usb_audio_dbg(ep->chip, "Starting %s EP 0x%x (running %d)\n",
1565 ep_type_name(ep->type), ep->ep_num,
1566 atomic_read(&ep->running));
1567
1568 /* already running? */
1569 if (atomic_inc_return(&ep->running) != 1)
1570 return 0;
1571
1572 if (ep->clock_ref)
1573 atomic_inc(&ep->clock_ref->locked);
1574
1575 ep->active_mask = 0;
1576 ep->unlink_mask = 0;
1577 ep->phase = 0;
1578 ep->sample_accum = 0;
1579
1580 snd_usb_endpoint_start_quirk(ep);
1581
1582 /*
1583 * If this endpoint has a data endpoint as implicit feedback source,
1584 * don't start the urbs here. Instead, mark them all as available,
1585 * wait for the record urbs to return and queue the playback urbs
1586 * from that context.
1587 */
1588
1589 if (!ep_state_update(ep, EP_STATE_STOPPED, EP_STATE_RUNNING))
1590 goto __error;
1591
1592 if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1593 !(ep->chip->quirk_flags & QUIRK_FLAG_PLAYBACK_FIRST)) {
1594 usb_audio_dbg(ep->chip, "No URB submission due to implicit fb sync\n");
1595 i = 0;
1596 goto fill_rest;
1597 }
1598
1599 for (i = 0; i < ep->nurbs; i++) {
1600 struct urb *urb = ep->urb[i].urb;
1601
1602 if (snd_BUG_ON(!urb))
1603 goto __error;
1604
1605 if (is_playback)
1606 err = prepare_outbound_urb(ep, urb->context, true);
1607 else
1608 err = prepare_inbound_urb(ep, urb->context);
1609 if (err < 0) {
1610 /* stop filling at applptr */
1611 if (err == -EAGAIN)
1612 break;
1613 usb_audio_dbg(ep->chip,
1614 "EP 0x%x: failed to prepare urb: %d\n",
1615 ep->ep_num, err);
1616 goto __error;
1617 }
1618
1619 if (!atomic_read(&ep->chip->shutdown))
1620 err = usb_submit_urb(urb, GFP_ATOMIC);
1621 else
1622 err = -ENODEV;
1623 if (err < 0) {
1624 if (!atomic_read(&ep->chip->shutdown))
1625 usb_audio_err(ep->chip,
1626 "cannot submit urb %d, error %d: %s\n",
1627 i, err, usb_error_string(err));
1628 goto __error;
1629 }
1630 set_bit(i, &ep->active_mask);
1631 atomic_inc(&ep->submitted_urbs);
1632 }
1633
1634 if (!i) {
1635 usb_audio_dbg(ep->chip, "XRUN at starting EP 0x%x\n",
1636 ep->ep_num);
1637 goto __error;
1638 }
1639
1640 usb_audio_dbg(ep->chip, "%d URBs submitted for EP 0x%x\n",
1641 i, ep->ep_num);
1642
1643 fill_rest:
1644 /* put the remaining URBs to ready list */
1645 if (is_playback) {
1646 for (; i < ep->nurbs; i++)
1647 push_back_to_ready_list(ep, ep->urb + i);
1648 }
1649
1650 return 0;
1651
1652 __error:
1653 snd_usb_endpoint_stop(ep, false);
1654 return -EPIPE;
1655 }
1656
1657 /**
1658 * snd_usb_endpoint_stop: stop an snd_usb_endpoint
1659 *
1660 * @ep: the endpoint to stop (may be NULL)
1661 * @keep_pending: keep in-flight URBs
1662 *
1663 * A call to this function will decrement the running count of the endpoint.
1664 * In case the last user has requested the endpoint stop, the URBs will
1665 * actually be deactivated.
1666 *
1667 * Must be balanced to calls of snd_usb_endpoint_start().
1668 *
1669 * The caller needs to synchronize the pending stop operation via
1670 * snd_usb_endpoint_sync_pending_stop().
1671 */
snd_usb_endpoint_stop(struct snd_usb_endpoint * ep,bool keep_pending)1672 void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep, bool keep_pending)
1673 {
1674 if (!ep)
1675 return;
1676
1677 usb_audio_dbg(ep->chip, "Stopping %s EP 0x%x (running %d)\n",
1678 ep_type_name(ep->type), ep->ep_num,
1679 atomic_read(&ep->running));
1680
1681 if (snd_BUG_ON(!atomic_read(&ep->running)))
1682 return;
1683
1684 if (!atomic_dec_return(&ep->running)) {
1685 if (ep->sync_source)
1686 WRITE_ONCE(ep->sync_source->sync_sink, NULL);
1687 stop_urbs(ep, false, keep_pending);
1688 if (ep->clock_ref)
1689 atomic_dec(&ep->clock_ref->locked);
1690
1691 if (ep->chip->quirk_flags & QUIRK_FLAG_FORCE_IFACE_RESET &&
1692 usb_pipeout(ep->pipe)) {
1693 ep->need_prepare = true;
1694 if (ep->iface_ref)
1695 ep->iface_ref->need_setup = true;
1696 }
1697 }
1698 }
1699
1700 /**
1701 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint
1702 *
1703 * @ep: the endpoint to release
1704 *
1705 * This function does not care for the endpoint's running count but will tear
1706 * down all the streaming URBs immediately.
1707 */
snd_usb_endpoint_release(struct snd_usb_endpoint * ep)1708 void snd_usb_endpoint_release(struct snd_usb_endpoint *ep)
1709 {
1710 release_urbs(ep, true);
1711 }
1712
1713 /**
1714 * snd_usb_endpoint_free_all: Free the resources of an snd_usb_endpoint
1715 * @chip: The chip
1716 *
1717 * This free all endpoints and those resources
1718 */
snd_usb_endpoint_free_all(struct snd_usb_audio * chip)1719 void snd_usb_endpoint_free_all(struct snd_usb_audio *chip)
1720 {
1721 struct snd_usb_endpoint *ep, *en;
1722 struct snd_usb_iface_ref *ip, *in;
1723 struct snd_usb_clock_ref *cp, *cn;
1724
1725 list_for_each_entry_safe(ep, en, &chip->ep_list, list)
1726 kfree(ep);
1727
1728 list_for_each_entry_safe(ip, in, &chip->iface_ref_list, list)
1729 kfree(ip);
1730
1731 list_for_each_entry_safe(cp, cn, &chip->clock_ref_list, list)
1732 kfree(cp);
1733 }
1734
1735 /*
1736 * snd_usb_handle_sync_urb: parse an USB sync packet
1737 *
1738 * @ep: the endpoint to handle the packet
1739 * @sender: the sending endpoint
1740 * @urb: the received packet
1741 *
1742 * This function is called from the context of an endpoint that received
1743 * the packet and is used to let another endpoint object handle the payload.
1744 */
snd_usb_handle_sync_urb(struct snd_usb_endpoint * ep,struct snd_usb_endpoint * sender,const struct urb * urb)1745 static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
1746 struct snd_usb_endpoint *sender,
1747 const struct urb *urb)
1748 {
1749 int shift;
1750 unsigned int f;
1751 unsigned long flags;
1752
1753 snd_BUG_ON(ep == sender);
1754
1755 /*
1756 * In case the endpoint is operating in implicit feedback mode, prepare
1757 * a new outbound URB that has the same layout as the received packet
1758 * and add it to the list of pending urbs. queue_pending_output_urbs()
1759 * will take care of them later.
1760 */
1761 if (snd_usb_endpoint_implicit_feedback_sink(ep) &&
1762 atomic_read(&ep->running)) {
1763
1764 /* implicit feedback case */
1765 int i, bytes = 0;
1766 struct snd_urb_ctx *in_ctx;
1767 struct snd_usb_packet_info *out_packet;
1768
1769 in_ctx = urb->context;
1770
1771 /* Count overall packet size */
1772 for (i = 0; i < in_ctx->packets; i++)
1773 if (urb->iso_frame_desc[i].status == 0)
1774 bytes += urb->iso_frame_desc[i].actual_length;
1775
1776 /*
1777 * skip empty packets. At least M-Audio's Fast Track Ultra stops
1778 * streaming once it received a 0-byte OUT URB
1779 */
1780 if (bytes == 0)
1781 return;
1782
1783 spin_lock_irqsave(&ep->lock, flags);
1784 if (ep->next_packet_queued >= ARRAY_SIZE(ep->next_packet)) {
1785 spin_unlock_irqrestore(&ep->lock, flags);
1786 usb_audio_err(ep->chip,
1787 "next package FIFO overflow EP 0x%x\n",
1788 ep->ep_num);
1789 notify_xrun(ep);
1790 return;
1791 }
1792
1793 out_packet = next_packet_fifo_enqueue(ep);
1794
1795 /*
1796 * Iterate through the inbound packet and prepare the lengths
1797 * for the output packet. The OUT packet we are about to send
1798 * will have the same amount of payload bytes per stride as the
1799 * IN packet we just received. Since the actual size is scaled
1800 * by the stride, use the sender stride to calculate the length
1801 * in case the number of channels differ between the implicitly
1802 * fed-back endpoint and the synchronizing endpoint.
1803 */
1804
1805 out_packet->packets = in_ctx->packets;
1806 for (i = 0; i < in_ctx->packets; i++) {
1807 if (urb->iso_frame_desc[i].status == 0)
1808 out_packet->packet_size[i] =
1809 urb->iso_frame_desc[i].actual_length / sender->stride;
1810 else
1811 out_packet->packet_size[i] = 0;
1812 }
1813
1814 spin_unlock_irqrestore(&ep->lock, flags);
1815 snd_usb_queue_pending_output_urbs(ep, false);
1816
1817 return;
1818 }
1819
1820 /*
1821 * process after playback sync complete
1822 *
1823 * Full speed devices report feedback values in 10.14 format as samples
1824 * per frame, high speed devices in 16.16 format as samples per
1825 * microframe.
1826 *
1827 * Because the Audio Class 1 spec was written before USB 2.0, many high
1828 * speed devices use a wrong interpretation, some others use an
1829 * entirely different format.
1830 *
1831 * Therefore, we cannot predict what format any particular device uses
1832 * and must detect it automatically.
1833 */
1834
1835 if (urb->iso_frame_desc[0].status != 0 ||
1836 urb->iso_frame_desc[0].actual_length < 3)
1837 return;
1838
1839 f = le32_to_cpup(urb->transfer_buffer);
1840 if (urb->iso_frame_desc[0].actual_length == 3)
1841 f &= 0x00ffffff;
1842 else
1843 f &= 0x0fffffff;
1844
1845 if (f == 0)
1846 return;
1847
1848 if (unlikely(sender->tenor_fb_quirk)) {
1849 /*
1850 * Devices based on Tenor 8802 chipsets (TEAC UD-H01
1851 * and others) sometimes change the feedback value
1852 * by +/- 0x1.0000.
1853 */
1854 if (f < ep->freqn - 0x8000)
1855 f += 0xf000;
1856 else if (f > ep->freqn + 0x8000)
1857 f -= 0xf000;
1858 } else if (unlikely(ep->freqshift == INT_MIN)) {
1859 /*
1860 * The first time we see a feedback value, determine its format
1861 * by shifting it left or right until it matches the nominal
1862 * frequency value. This assumes that the feedback does not
1863 * differ from the nominal value more than +50% or -25%.
1864 */
1865 shift = 0;
1866 while (f < ep->freqn - ep->freqn / 4) {
1867 f <<= 1;
1868 shift++;
1869 }
1870 while (f > ep->freqn + ep->freqn / 2) {
1871 f >>= 1;
1872 shift--;
1873 }
1874 ep->freqshift = shift;
1875 } else if (ep->freqshift >= 0)
1876 f <<= ep->freqshift;
1877 else
1878 f >>= -ep->freqshift;
1879
1880 if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) {
1881 /*
1882 * If the frequency looks valid, set it.
1883 * This value is referred to in prepare_playback_urb().
1884 */
1885 spin_lock_irqsave(&ep->lock, flags);
1886 ep->freqm = f;
1887 spin_unlock_irqrestore(&ep->lock, flags);
1888 } else {
1889 /*
1890 * Out of range; maybe the shift value is wrong.
1891 * Reset it so that we autodetect again the next time.
1892 */
1893 ep->freqshift = INT_MIN;
1894 }
1895 }
1896
1897