xref: /linux/sound/usb/pcm.c (revision 0bc1bd092af3c7c0b025ece93c3a86916f89f3ca)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  */
4 
5 #include <linux/init.h>
6 #include <linux/slab.h>
7 #include <linux/bitrev.h>
8 #include <linux/ratelimit.h>
9 #include <linux/usb.h>
10 #include <linux/usb/audio.h>
11 #include <linux/usb/audio-v2.h>
12 
13 #include <sound/core.h>
14 #include <sound/pcm.h>
15 #include <sound/pcm_params.h>
16 
17 #include "usbaudio.h"
18 #include "card.h"
19 #include "quirks.h"
20 #include "endpoint.h"
21 #include "helper.h"
22 #include "pcm.h"
23 #include "clock.h"
24 #include "power.h"
25 #include "media.h"
26 #include "implicit.h"
27 
28 #define SUBSTREAM_FLAG_DATA_EP_STARTED	0
29 #define SUBSTREAM_FLAG_SYNC_EP_STARTED	1
30 
31 /* return the estimated delay based on USB frame counters */
32 snd_pcm_uframes_t snd_usb_pcm_delay(struct snd_usb_substream *subs,
33 				    unsigned int rate)
34 {
35 	int current_frame_number;
36 	int frame_diff;
37 	int est_delay;
38 
39 	if (!subs->last_delay)
40 		return 0; /* short path */
41 
42 	current_frame_number = usb_get_current_frame_number(subs->dev);
43 	/*
44 	 * HCD implementations use different widths, use lower 8 bits.
45 	 * The delay will be managed up to 256ms, which is more than
46 	 * enough
47 	 */
48 	frame_diff = (current_frame_number - subs->last_frame_number) & 0xff;
49 
50 	/* Approximation based on number of samples per USB frame (ms),
51 	   some truncation for 44.1 but the estimate is good enough */
52 	est_delay =  frame_diff * rate / 1000;
53 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
54 		est_delay = subs->last_delay - est_delay;
55 	else
56 		est_delay = subs->last_delay + est_delay;
57 
58 	if (est_delay < 0)
59 		est_delay = 0;
60 	return est_delay;
61 }
62 
63 /*
64  * return the current pcm pointer.  just based on the hwptr_done value.
65  */
66 static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream)
67 {
68 	struct snd_usb_substream *subs = substream->runtime->private_data;
69 	unsigned int hwptr_done;
70 
71 	if (atomic_read(&subs->stream->chip->shutdown))
72 		return SNDRV_PCM_POS_XRUN;
73 	spin_lock(&subs->lock);
74 	hwptr_done = subs->hwptr_done;
75 	substream->runtime->delay = snd_usb_pcm_delay(subs,
76 						substream->runtime->rate);
77 	spin_unlock(&subs->lock);
78 	return hwptr_done / (substream->runtime->frame_bits >> 3);
79 }
80 
81 /*
82  * find a matching audio format
83  */
84 static const struct audioformat *
85 find_format(struct list_head *fmt_list_head, snd_pcm_format_t format,
86 	    unsigned int rate, unsigned int channels, bool strict_match,
87 	    struct snd_usb_substream *subs)
88 {
89 	const struct audioformat *fp;
90 	const struct audioformat *found = NULL;
91 	int cur_attr = 0, attr;
92 
93 	list_for_each_entry(fp, fmt_list_head, list) {
94 		if (strict_match) {
95 			if (!(fp->formats & pcm_format_to_bits(format)))
96 				continue;
97 			if (fp->channels != channels)
98 				continue;
99 		}
100 		if (rate < fp->rate_min || rate > fp->rate_max)
101 			continue;
102 		if (!(fp->rates & SNDRV_PCM_RATE_CONTINUOUS)) {
103 			unsigned int i;
104 			for (i = 0; i < fp->nr_rates; i++)
105 				if (fp->rate_table[i] == rate)
106 					break;
107 			if (i >= fp->nr_rates)
108 				continue;
109 		}
110 		attr = fp->ep_attr & USB_ENDPOINT_SYNCTYPE;
111 		if (!found) {
112 			found = fp;
113 			cur_attr = attr;
114 			continue;
115 		}
116 		/* avoid async out and adaptive in if the other method
117 		 * supports the same format.
118 		 * this is a workaround for the case like
119 		 * M-audio audiophile USB.
120 		 */
121 		if (subs && attr != cur_attr) {
122 			if ((attr == USB_ENDPOINT_SYNC_ASYNC &&
123 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
124 			    (attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
125 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE))
126 				continue;
127 			if ((cur_attr == USB_ENDPOINT_SYNC_ASYNC &&
128 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
129 			    (cur_attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
130 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE)) {
131 				found = fp;
132 				cur_attr = attr;
133 				continue;
134 			}
135 		}
136 		/* find the format with the largest max. packet size */
137 		if (fp->maxpacksize > found->maxpacksize) {
138 			found = fp;
139 			cur_attr = attr;
140 		}
141 	}
142 	return found;
143 }
144 
145 static const struct audioformat *
146 find_substream_format(struct snd_usb_substream *subs,
147 		      const struct snd_pcm_hw_params *params)
148 {
149 	return find_format(&subs->fmt_list, params_format(params),
150 			   params_rate(params), params_channels(params),
151 			   true, subs);
152 }
153 
154 static int init_pitch_v1(struct snd_usb_audio *chip, int ep)
155 {
156 	struct usb_device *dev = chip->dev;
157 	unsigned char data[1];
158 	int err;
159 
160 	data[0] = 1;
161 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
162 			      USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
163 			      UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep,
164 			      data, sizeof(data));
165 	return err;
166 }
167 
168 static int init_pitch_v2(struct snd_usb_audio *chip, int ep)
169 {
170 	struct usb_device *dev = chip->dev;
171 	unsigned char data[1];
172 	int err;
173 
174 	data[0] = 1;
175 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
176 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
177 			      UAC2_EP_CS_PITCH << 8, 0,
178 			      data, sizeof(data));
179 	return err;
180 }
181 
182 /*
183  * initialize the pitch control and sample rate
184  */
185 int snd_usb_init_pitch(struct snd_usb_audio *chip,
186 		       const struct audioformat *fmt)
187 {
188 	int err;
189 
190 	/* if endpoint doesn't have pitch control, bail out */
191 	if (!(fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL))
192 		return 0;
193 
194 	usb_audio_dbg(chip, "enable PITCH for EP 0x%x\n", fmt->endpoint);
195 
196 	switch (fmt->protocol) {
197 	case UAC_VERSION_1:
198 		err = init_pitch_v1(chip, fmt->endpoint);
199 		break;
200 	case UAC_VERSION_2:
201 		err = init_pitch_v2(chip, fmt->endpoint);
202 		break;
203 	default:
204 		return 0;
205 	}
206 
207 	if (err < 0) {
208 		usb_audio_err(chip, "failed to enable PITCH for EP 0x%x\n",
209 			      fmt->endpoint);
210 		return err;
211 	}
212 
213 	return 0;
214 }
215 
216 static bool stop_endpoints(struct snd_usb_substream *subs)
217 {
218 	bool stopped = 0;
219 
220 	if (test_and_clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) {
221 		snd_usb_endpoint_stop(subs->sync_endpoint);
222 		stopped = true;
223 	}
224 	if (test_and_clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags)) {
225 		snd_usb_endpoint_stop(subs->data_endpoint);
226 		stopped = true;
227 	}
228 	return stopped;
229 }
230 
231 static int start_endpoints(struct snd_usb_substream *subs)
232 {
233 	int err;
234 
235 	if (!subs->data_endpoint)
236 		return -EINVAL;
237 
238 	if (!test_and_set_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags)) {
239 		err = snd_usb_endpoint_start(subs->data_endpoint);
240 		if (err < 0) {
241 			clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags);
242 			goto error;
243 		}
244 	}
245 
246 	if (subs->sync_endpoint &&
247 	    !test_and_set_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) {
248 		err = snd_usb_endpoint_start(subs->sync_endpoint);
249 		if (err < 0) {
250 			clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
251 			goto error;
252 		}
253 	}
254 
255 	return 0;
256 
257  error:
258 	stop_endpoints(subs);
259 	return err;
260 }
261 
262 static void sync_pending_stops(struct snd_usb_substream *subs)
263 {
264 	snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
265 	snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
266 }
267 
268 /* PCM sync_stop callback */
269 static int snd_usb_pcm_sync_stop(struct snd_pcm_substream *substream)
270 {
271 	struct snd_usb_substream *subs = substream->runtime->private_data;
272 
273 	if (!snd_usb_lock_shutdown(subs->stream->chip)) {
274 		sync_pending_stops(subs);
275 		snd_usb_unlock_shutdown(subs->stream->chip);
276 	}
277 	return 0;
278 }
279 
280 /* Set up sync endpoint */
281 int snd_usb_audioformat_set_sync_ep(struct snd_usb_audio *chip,
282 				    struct audioformat *fmt)
283 {
284 	struct usb_device *dev = chip->dev;
285 	struct usb_host_interface *alts;
286 	struct usb_interface_descriptor *altsd;
287 	unsigned int ep, attr, sync_attr;
288 	bool is_playback;
289 	int err;
290 
291 	alts = snd_usb_get_host_interface(chip, fmt->iface, fmt->altsetting);
292 	if (!alts)
293 		return 0;
294 	altsd = get_iface_desc(alts);
295 
296 	err = snd_usb_parse_implicit_fb_quirk(chip, fmt, alts);
297 	if (err > 0)
298 		return 0; /* matched */
299 
300 	/*
301 	 * Generic sync EP handling
302 	 */
303 
304 	if (altsd->bNumEndpoints < 2)
305 		return 0;
306 
307 	is_playback = !(get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN);
308 	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
309 	if ((is_playback && (attr == USB_ENDPOINT_SYNC_SYNC ||
310 			     attr == USB_ENDPOINT_SYNC_ADAPTIVE)) ||
311 	    (!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE))
312 		return 0;
313 
314 	sync_attr = get_endpoint(alts, 1)->bmAttributes;
315 
316 	/*
317 	 * In case of illegal SYNC_NONE for OUT endpoint, we keep going to see
318 	 * if we don't find a sync endpoint, as on M-Audio Transit. In case of
319 	 * error fall back to SYNC mode and don't create sync endpoint
320 	 */
321 
322 	/* check sync-pipe endpoint */
323 	/* ... and check descriptor size before accessing bSynchAddress
324 	   because there is a version of the SB Audigy 2 NX firmware lacking
325 	   the audio fields in the endpoint descriptors */
326 	if ((sync_attr & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC ||
327 	    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
328 	     get_endpoint(alts, 1)->bSynchAddress != 0)) {
329 		dev_err(&dev->dev,
330 			"%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
331 			   fmt->iface, fmt->altsetting,
332 			   get_endpoint(alts, 1)->bmAttributes,
333 			   get_endpoint(alts, 1)->bLength,
334 			   get_endpoint(alts, 1)->bSynchAddress);
335 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
336 			return 0;
337 		return -EINVAL;
338 	}
339 	ep = get_endpoint(alts, 1)->bEndpointAddress;
340 	if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
341 	    get_endpoint(alts, 0)->bSynchAddress != 0 &&
342 	    ((is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
343 	     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
344 		dev_err(&dev->dev,
345 			"%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
346 			   fmt->iface, fmt->altsetting,
347 			   is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
348 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
349 			return 0;
350 		return -EINVAL;
351 	}
352 
353 	fmt->sync_ep = ep;
354 	fmt->sync_iface = altsd->bInterfaceNumber;
355 	fmt->sync_altsetting = altsd->bAlternateSetting;
356 	fmt->sync_ep_idx = 1;
357 	if ((sync_attr & USB_ENDPOINT_USAGE_MASK) == USB_ENDPOINT_USAGE_IMPLICIT_FB)
358 		fmt->implicit_fb = 1;
359 
360 	dev_dbg(&dev->dev, "%d:%d: found sync_ep=0x%x, iface=%d, alt=%d, implicit_fb=%d\n",
361 		fmt->iface, fmt->altsetting, fmt->sync_ep, fmt->sync_iface,
362 		fmt->sync_altsetting, fmt->implicit_fb);
363 
364 	return 0;
365 }
366 
367 static int snd_usb_pcm_change_state(struct snd_usb_substream *subs, int state)
368 {
369 	int ret;
370 
371 	if (!subs->str_pd)
372 		return 0;
373 
374 	ret = snd_usb_power_domain_set(subs->stream->chip, subs->str_pd, state);
375 	if (ret < 0) {
376 		dev_err(&subs->dev->dev,
377 			"Cannot change Power Domain ID: %d to state: %d. Err: %d\n",
378 			subs->str_pd->pd_id, state, ret);
379 		return ret;
380 	}
381 
382 	return 0;
383 }
384 
385 int snd_usb_pcm_suspend(struct snd_usb_stream *as)
386 {
387 	int ret;
388 
389 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D2);
390 	if (ret < 0)
391 		return ret;
392 
393 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D2);
394 	if (ret < 0)
395 		return ret;
396 
397 	return 0;
398 }
399 
400 int snd_usb_pcm_resume(struct snd_usb_stream *as)
401 {
402 	int ret;
403 
404 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D1);
405 	if (ret < 0)
406 		return ret;
407 
408 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D1);
409 	if (ret < 0)
410 		return ret;
411 
412 	return 0;
413 }
414 
415 static void close_endpoints(struct snd_usb_audio *chip,
416 			    struct snd_usb_substream *subs)
417 {
418 	if (subs->data_endpoint) {
419 		snd_usb_endpoint_set_sync(chip, subs->data_endpoint, NULL);
420 		snd_usb_endpoint_close(chip, subs->data_endpoint);
421 		subs->data_endpoint = NULL;
422 	}
423 
424 	if (subs->sync_endpoint) {
425 		snd_usb_endpoint_close(chip, subs->sync_endpoint);
426 		subs->sync_endpoint = NULL;
427 	}
428 }
429 
430 static int configure_endpoints(struct snd_usb_audio *chip,
431 			       struct snd_usb_substream *subs)
432 {
433 	int err;
434 
435 	if (subs->data_endpoint->need_setup) {
436 		/* stop any running stream beforehand */
437 		if (stop_endpoints(subs))
438 			sync_pending_stops(subs);
439 		err = snd_usb_endpoint_configure(chip, subs->data_endpoint);
440 		if (err < 0)
441 			return err;
442 		snd_usb_set_format_quirk(subs, subs->cur_audiofmt);
443 	}
444 
445 	if (subs->sync_endpoint) {
446 		err = snd_usb_endpoint_configure(chip, subs->sync_endpoint);
447 		if (err < 0)
448 			return err;
449 	}
450 
451 	return 0;
452 }
453 
454 /*
455  * hw_params callback
456  *
457  * allocate a buffer and set the given audio format.
458  *
459  * so far we use a physically linear buffer although packetize transfer
460  * doesn't need a continuous area.
461  * if sg buffer is supported on the later version of alsa, we'll follow
462  * that.
463  */
464 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
465 			     struct snd_pcm_hw_params *hw_params)
466 {
467 	struct snd_usb_substream *subs = substream->runtime->private_data;
468 	struct snd_usb_audio *chip = subs->stream->chip;
469 	const struct audioformat *fmt;
470 	const struct audioformat *sync_fmt;
471 	int ret;
472 
473 	ret = snd_media_start_pipeline(subs);
474 	if (ret)
475 		return ret;
476 
477 	fmt = find_substream_format(subs, hw_params);
478 	if (!fmt) {
479 		usb_audio_dbg(chip,
480 			      "cannot find format: format=%s, rate=%d, channels=%d\n",
481 			      snd_pcm_format_name(params_format(hw_params)),
482 			      params_rate(hw_params), params_channels(hw_params));
483 		ret = -EINVAL;
484 		goto stop_pipeline;
485 	}
486 
487 	if (fmt->implicit_fb) {
488 		sync_fmt = snd_usb_find_implicit_fb_sync_format(chip, fmt,
489 								hw_params,
490 								!substream->stream);
491 		if (!sync_fmt) {
492 			usb_audio_dbg(chip,
493 				      "cannot find sync format: ep=0x%x, iface=%d:%d, format=%s, rate=%d, channels=%d\n",
494 				      fmt->sync_ep, fmt->sync_iface,
495 				      fmt->sync_altsetting,
496 				      snd_pcm_format_name(params_format(hw_params)),
497 				      params_rate(hw_params), params_channels(hw_params));
498 			ret = -EINVAL;
499 			goto stop_pipeline;
500 		}
501 	} else {
502 		sync_fmt = fmt;
503 	}
504 
505 	ret = snd_usb_lock_shutdown(chip);
506 	if (ret < 0)
507 		goto stop_pipeline;
508 
509 	ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
510 	if (ret < 0)
511 		goto unlock;
512 
513 	if (subs->data_endpoint) {
514 		if (snd_usb_endpoint_compatible(chip, subs->data_endpoint,
515 						fmt, hw_params))
516 			goto unlock;
517 		close_endpoints(chip, subs);
518 	}
519 
520 	subs->data_endpoint = snd_usb_endpoint_open(chip, fmt, hw_params, false);
521 	if (!subs->data_endpoint) {
522 		ret = -EINVAL;
523 		goto unlock;
524 	}
525 
526 	if (fmt->sync_ep) {
527 		subs->sync_endpoint = snd_usb_endpoint_open(chip, sync_fmt,
528 							    hw_params,
529 							    fmt == sync_fmt);
530 		if (!subs->sync_endpoint) {
531 			ret = -EINVAL;
532 			goto unlock;
533 		}
534 
535 		snd_usb_endpoint_set_sync(chip, subs->data_endpoint,
536 					  subs->sync_endpoint);
537 	}
538 
539 	mutex_lock(&chip->mutex);
540 	subs->cur_audiofmt = fmt;
541 	mutex_unlock(&chip->mutex);
542 
543 	ret = configure_endpoints(chip, subs);
544 
545  unlock:
546 	if (ret < 0)
547 		close_endpoints(chip, subs);
548 
549 	snd_usb_unlock_shutdown(chip);
550  stop_pipeline:
551 	if (ret < 0)
552 		snd_media_stop_pipeline(subs);
553 
554 	return ret;
555 }
556 
557 /*
558  * hw_free callback
559  *
560  * reset the audio format and release the buffer
561  */
562 static int snd_usb_hw_free(struct snd_pcm_substream *substream)
563 {
564 	struct snd_usb_substream *subs = substream->runtime->private_data;
565 	struct snd_usb_audio *chip = subs->stream->chip;
566 
567 	snd_media_stop_pipeline(subs);
568 	mutex_lock(&chip->mutex);
569 	subs->cur_audiofmt = NULL;
570 	mutex_unlock(&chip->mutex);
571 	if (!snd_usb_lock_shutdown(chip)) {
572 		if (stop_endpoints(subs))
573 			sync_pending_stops(subs);
574 		close_endpoints(chip, subs);
575 		snd_usb_unlock_shutdown(chip);
576 	}
577 
578 	return 0;
579 }
580 
581 /*
582  * prepare callback
583  *
584  * only a few subtle things...
585  */
586 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
587 {
588 	struct snd_pcm_runtime *runtime = substream->runtime;
589 	struct snd_usb_substream *subs = runtime->private_data;
590 	struct snd_usb_audio *chip = subs->stream->chip;
591 	int ret;
592 
593 	ret = snd_usb_lock_shutdown(chip);
594 	if (ret < 0)
595 		return ret;
596 	if (snd_BUG_ON(!subs->data_endpoint)) {
597 		ret = -EIO;
598 		goto unlock;
599 	}
600 
601 	ret = configure_endpoints(chip, subs);
602 	if (ret < 0)
603 		goto unlock;
604 
605 	/* reset the pointer */
606 	subs->hwptr_done = 0;
607 	subs->transfer_done = 0;
608 	subs->last_delay = 0;
609 	subs->last_frame_number = 0;
610 	runtime->delay = 0;
611 
612 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
613 	 * updates for all URBs would happen at the same time when starting */
614 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
615 		ret = start_endpoints(subs);
616 
617  unlock:
618 	snd_usb_unlock_shutdown(chip);
619 	return ret;
620 }
621 
622 /*
623  * h/w constraints
624  */
625 
626 #ifdef HW_CONST_DEBUG
627 #define hwc_debug(fmt, args...) pr_debug(fmt, ##args)
628 #else
629 #define hwc_debug(fmt, args...) do { } while(0)
630 #endif
631 
632 static const struct snd_pcm_hardware snd_usb_hardware =
633 {
634 	.info =			SNDRV_PCM_INFO_MMAP |
635 				SNDRV_PCM_INFO_MMAP_VALID |
636 				SNDRV_PCM_INFO_BATCH |
637 				SNDRV_PCM_INFO_INTERLEAVED |
638 				SNDRV_PCM_INFO_BLOCK_TRANSFER |
639 				SNDRV_PCM_INFO_PAUSE,
640 	.channels_min =		1,
641 	.channels_max =		256,
642 	.buffer_bytes_max =	1024 * 1024,
643 	.period_bytes_min =	64,
644 	.period_bytes_max =	512 * 1024,
645 	.periods_min =		2,
646 	.periods_max =		1024,
647 };
648 
649 static int hw_check_valid_format(struct snd_usb_substream *subs,
650 				 struct snd_pcm_hw_params *params,
651 				 const struct audioformat *fp)
652 {
653 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
654 	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
655 	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
656 	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
657 	struct snd_mask check_fmts;
658 	unsigned int ptime;
659 
660 	/* check the format */
661 	snd_mask_none(&check_fmts);
662 	check_fmts.bits[0] = (u32)fp->formats;
663 	check_fmts.bits[1] = (u32)(fp->formats >> 32);
664 	snd_mask_intersect(&check_fmts, fmts);
665 	if (snd_mask_empty(&check_fmts)) {
666 		hwc_debug("   > check: no supported format %d\n", fp->format);
667 		return 0;
668 	}
669 	/* check the channels */
670 	if (fp->channels < ct->min || fp->channels > ct->max) {
671 		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
672 		return 0;
673 	}
674 	/* check the rate is within the range */
675 	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
676 		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
677 		return 0;
678 	}
679 	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
680 		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
681 		return 0;
682 	}
683 	/* check whether the period time is >= the data packet interval */
684 	if (subs->speed != USB_SPEED_FULL) {
685 		ptime = 125 * (1 << fp->datainterval);
686 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
687 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
688 			return 0;
689 		}
690 	}
691 	return 1;
692 }
693 
694 static int apply_hw_params_minmax(struct snd_interval *it, unsigned int rmin,
695 				  unsigned int rmax)
696 {
697 	int changed;
698 
699 	if (rmin > rmax) {
700 		hwc_debug("  --> get empty\n");
701 		it->empty = 1;
702 		return -EINVAL;
703 	}
704 
705 	changed = 0;
706 	if (it->min < rmin) {
707 		it->min = rmin;
708 		it->openmin = 0;
709 		changed = 1;
710 	}
711 	if (it->max > rmax) {
712 		it->max = rmax;
713 		it->openmax = 0;
714 		changed = 1;
715 	}
716 	if (snd_interval_checkempty(it)) {
717 		it->empty = 1;
718 		return -EINVAL;
719 	}
720 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
721 	return changed;
722 }
723 
724 static int hw_rule_rate(struct snd_pcm_hw_params *params,
725 			struct snd_pcm_hw_rule *rule)
726 {
727 	struct snd_usb_substream *subs = rule->private;
728 	const struct audioformat *fp;
729 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
730 	unsigned int rmin, rmax, r;
731 	int i;
732 
733 	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
734 	rmin = UINT_MAX;
735 	rmax = 0;
736 	list_for_each_entry(fp, &subs->fmt_list, list) {
737 		if (!hw_check_valid_format(subs, params, fp))
738 			continue;
739 		if (fp->rate_table && fp->nr_rates) {
740 			for (i = 0; i < fp->nr_rates; i++) {
741 				r = fp->rate_table[i];
742 				if (!snd_interval_test(it, r))
743 					continue;
744 				rmin = min(rmin, r);
745 				rmax = max(rmax, r);
746 			}
747 		} else {
748 			rmin = min(rmin, fp->rate_min);
749 			rmax = max(rmax, fp->rate_max);
750 		}
751 	}
752 
753 	return apply_hw_params_minmax(it, rmin, rmax);
754 }
755 
756 
757 static int hw_rule_channels(struct snd_pcm_hw_params *params,
758 			    struct snd_pcm_hw_rule *rule)
759 {
760 	struct snd_usb_substream *subs = rule->private;
761 	const struct audioformat *fp;
762 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
763 	unsigned int rmin, rmax;
764 
765 	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
766 	rmin = UINT_MAX;
767 	rmax = 0;
768 	list_for_each_entry(fp, &subs->fmt_list, list) {
769 		if (!hw_check_valid_format(subs, params, fp))
770 			continue;
771 		rmin = min(rmin, fp->channels);
772 		rmax = max(rmax, fp->channels);
773 	}
774 
775 	return apply_hw_params_minmax(it, rmin, rmax);
776 }
777 
778 static int hw_rule_format(struct snd_pcm_hw_params *params,
779 			  struct snd_pcm_hw_rule *rule)
780 {
781 	struct snd_usb_substream *subs = rule->private;
782 	const struct audioformat *fp;
783 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
784 	u64 fbits;
785 	u32 oldbits[2];
786 	int changed;
787 
788 	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
789 	fbits = 0;
790 	list_for_each_entry(fp, &subs->fmt_list, list) {
791 		if (!hw_check_valid_format(subs, params, fp))
792 			continue;
793 		fbits |= fp->formats;
794 	}
795 
796 	oldbits[0] = fmt->bits[0];
797 	oldbits[1] = fmt->bits[1];
798 	fmt->bits[0] &= (u32)fbits;
799 	fmt->bits[1] &= (u32)(fbits >> 32);
800 	if (!fmt->bits[0] && !fmt->bits[1]) {
801 		hwc_debug("  --> get empty\n");
802 		return -EINVAL;
803 	}
804 	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
805 	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
806 	return changed;
807 }
808 
809 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
810 			       struct snd_pcm_hw_rule *rule)
811 {
812 	struct snd_usb_substream *subs = rule->private;
813 	const struct audioformat *fp;
814 	struct snd_interval *it;
815 	unsigned char min_datainterval;
816 	unsigned int pmin;
817 
818 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
819 	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
820 	min_datainterval = 0xff;
821 	list_for_each_entry(fp, &subs->fmt_list, list) {
822 		if (!hw_check_valid_format(subs, params, fp))
823 			continue;
824 		min_datainterval = min(min_datainterval, fp->datainterval);
825 	}
826 	if (min_datainterval == 0xff) {
827 		hwc_debug("  --> get empty\n");
828 		it->empty = 1;
829 		return -EINVAL;
830 	}
831 	pmin = 125 * (1 << min_datainterval);
832 
833 	return apply_hw_params_minmax(it, pmin, UINT_MAX);
834 }
835 
836 /* apply PCM hw constraints from the concurrent sync EP */
837 static int apply_hw_constraint_from_sync(struct snd_pcm_runtime *runtime,
838 					 struct snd_usb_substream *subs)
839 {
840 	struct snd_usb_audio *chip = subs->stream->chip;
841 	struct snd_usb_endpoint *ep;
842 	const struct audioformat *fp;
843 	int err;
844 
845 	list_for_each_entry(fp, &subs->fmt_list, list) {
846 		ep = snd_usb_get_endpoint(chip, fp->endpoint);
847 		if (ep && ep->cur_rate)
848 			goto found;
849 		if (!fp->implicit_fb)
850 			continue;
851 		/* for the implicit fb, check the sync ep as well */
852 		ep = snd_usb_get_endpoint(chip, fp->sync_ep);
853 		if (ep && ep->cur_rate)
854 			goto found;
855 	}
856 	return 0;
857 
858  found:
859 	if (!find_format(&subs->fmt_list, ep->cur_format, ep->cur_rate,
860 			 ep->cur_channels, false, NULL)) {
861 		usb_audio_dbg(chip, "EP 0x%x being used, but not applicable\n",
862 			      ep->ep_num);
863 		return 0;
864 	}
865 
866 	usb_audio_dbg(chip, "EP 0x%x being used, using fixed params:\n",
867 		      ep->ep_num);
868 	usb_audio_dbg(chip, "rate=%d, period_size=%d, periods=%d\n",
869 		      ep->cur_rate, ep->cur_period_frames,
870 		      ep->cur_buffer_periods);
871 
872 	runtime->hw.formats = subs->formats;
873 	runtime->hw.rate_min = runtime->hw.rate_max = ep->cur_rate;
874 	runtime->hw.rates = SNDRV_PCM_RATE_KNOT;
875 	runtime->hw.periods_min = runtime->hw.periods_max =
876 		ep->cur_buffer_periods;
877 
878 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
879 				  hw_rule_channels, subs,
880 				  SNDRV_PCM_HW_PARAM_FORMAT,
881 				  SNDRV_PCM_HW_PARAM_RATE,
882 				  -1);
883 	if (err < 0)
884 		return err;
885 
886 	err = snd_pcm_hw_constraint_minmax(runtime,
887 					   SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
888 					   ep->cur_period_frames,
889 					   ep->cur_period_frames);
890 	if (err < 0)
891 		return err;
892 
893 	return 1; /* notify the finding */
894 }
895 
896 /*
897  * set up the runtime hardware information.
898  */
899 
900 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
901 {
902 	struct snd_usb_audio *chip = subs->stream->chip;
903 	const struct audioformat *fp;
904 	unsigned int pt, ptmin;
905 	int param_period_time_if_needed = -1;
906 	int err;
907 
908 	mutex_lock(&chip->mutex);
909 	err = apply_hw_constraint_from_sync(runtime, subs);
910 	mutex_unlock(&chip->mutex);
911 	if (err < 0)
912 		return err;
913 	if (err > 0) /* found the matching? */
914 		goto add_extra_rules;
915 
916 	runtime->hw.formats = subs->formats;
917 
918 	runtime->hw.rate_min = 0x7fffffff;
919 	runtime->hw.rate_max = 0;
920 	runtime->hw.channels_min = 256;
921 	runtime->hw.channels_max = 0;
922 	runtime->hw.rates = 0;
923 	ptmin = UINT_MAX;
924 	/* check min/max rates and channels */
925 	list_for_each_entry(fp, &subs->fmt_list, list) {
926 		runtime->hw.rates |= fp->rates;
927 		if (runtime->hw.rate_min > fp->rate_min)
928 			runtime->hw.rate_min = fp->rate_min;
929 		if (runtime->hw.rate_max < fp->rate_max)
930 			runtime->hw.rate_max = fp->rate_max;
931 		if (runtime->hw.channels_min > fp->channels)
932 			runtime->hw.channels_min = fp->channels;
933 		if (runtime->hw.channels_max < fp->channels)
934 			runtime->hw.channels_max = fp->channels;
935 		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
936 			/* FIXME: there might be more than one audio formats... */
937 			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
938 				fp->frame_size;
939 		}
940 		pt = 125 * (1 << fp->datainterval);
941 		ptmin = min(ptmin, pt);
942 	}
943 
944 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
945 	if (subs->speed == USB_SPEED_FULL)
946 		/* full speed devices have fixed data packet interval */
947 		ptmin = 1000;
948 	if (ptmin == 1000)
949 		/* if period time doesn't go below 1 ms, no rules needed */
950 		param_period_time_if_needed = -1;
951 
952 	err = snd_pcm_hw_constraint_minmax(runtime,
953 					   SNDRV_PCM_HW_PARAM_PERIOD_TIME,
954 					   ptmin, UINT_MAX);
955 	if (err < 0)
956 		return err;
957 
958 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
959 				  hw_rule_rate, subs,
960 				  SNDRV_PCM_HW_PARAM_FORMAT,
961 				  SNDRV_PCM_HW_PARAM_CHANNELS,
962 				  param_period_time_if_needed,
963 				  -1);
964 	if (err < 0)
965 		return err;
966 
967 add_extra_rules:
968 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
969 				  hw_rule_channels, subs,
970 				  SNDRV_PCM_HW_PARAM_FORMAT,
971 				  SNDRV_PCM_HW_PARAM_RATE,
972 				  param_period_time_if_needed,
973 				  -1);
974 	if (err < 0)
975 		return err;
976 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
977 				  hw_rule_format, subs,
978 				  SNDRV_PCM_HW_PARAM_RATE,
979 				  SNDRV_PCM_HW_PARAM_CHANNELS,
980 				  param_period_time_if_needed,
981 				  -1);
982 	if (err < 0)
983 		return err;
984 	if (param_period_time_if_needed >= 0) {
985 		err = snd_pcm_hw_rule_add(runtime, 0,
986 					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
987 					  hw_rule_period_time, subs,
988 					  SNDRV_PCM_HW_PARAM_FORMAT,
989 					  SNDRV_PCM_HW_PARAM_CHANNELS,
990 					  SNDRV_PCM_HW_PARAM_RATE,
991 					  -1);
992 		if (err < 0)
993 			return err;
994 	}
995 
996 	return 0;
997 }
998 
999 static int snd_usb_pcm_open(struct snd_pcm_substream *substream)
1000 {
1001 	int direction = substream->stream;
1002 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1003 	struct snd_pcm_runtime *runtime = substream->runtime;
1004 	struct snd_usb_substream *subs = &as->substream[direction];
1005 	int ret;
1006 
1007 	runtime->hw = snd_usb_hardware;
1008 	runtime->private_data = subs;
1009 	subs->pcm_substream = substream;
1010 	/* runtime PM is also done there */
1011 
1012 	/* initialize DSD/DOP context */
1013 	subs->dsd_dop.byte_idx = 0;
1014 	subs->dsd_dop.channel = 0;
1015 	subs->dsd_dop.marker = 1;
1016 
1017 	ret = setup_hw_info(runtime, subs);
1018 	if (ret < 0)
1019 		return ret;
1020 	ret = snd_usb_autoresume(subs->stream->chip);
1021 	if (ret < 0)
1022 		return ret;
1023 	ret = snd_media_stream_init(subs, as->pcm, direction);
1024 	if (ret < 0)
1025 		snd_usb_autosuspend(subs->stream->chip);
1026 	return ret;
1027 }
1028 
1029 static int snd_usb_pcm_close(struct snd_pcm_substream *substream)
1030 {
1031 	int direction = substream->stream;
1032 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1033 	struct snd_usb_substream *subs = &as->substream[direction];
1034 	int ret;
1035 
1036 	snd_media_stop_pipeline(subs);
1037 
1038 	if (!snd_usb_lock_shutdown(subs->stream->chip)) {
1039 		ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D1);
1040 		snd_usb_unlock_shutdown(subs->stream->chip);
1041 		if (ret < 0)
1042 			return ret;
1043 	}
1044 
1045 	subs->pcm_substream = NULL;
1046 	snd_usb_autosuspend(subs->stream->chip);
1047 
1048 	return 0;
1049 }
1050 
1051 /* Since a URB can handle only a single linear buffer, we must use double
1052  * buffering when the data to be transferred overflows the buffer boundary.
1053  * To avoid inconsistencies when updating hwptr_done, we use double buffering
1054  * for all URBs.
1055  */
1056 static void retire_capture_urb(struct snd_usb_substream *subs,
1057 			       struct urb *urb)
1058 {
1059 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1060 	unsigned int stride, frames, bytes, oldptr;
1061 	int i, period_elapsed = 0;
1062 	unsigned long flags;
1063 	unsigned char *cp;
1064 	int current_frame_number;
1065 
1066 	/* read frame number here, update pointer in critical section */
1067 	current_frame_number = usb_get_current_frame_number(subs->dev);
1068 
1069 	stride = runtime->frame_bits >> 3;
1070 
1071 	for (i = 0; i < urb->number_of_packets; i++) {
1072 		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset + subs->pkt_offset_adj;
1073 		if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
1074 			dev_dbg(&subs->dev->dev, "frame %d active: %d\n",
1075 				i, urb->iso_frame_desc[i].status);
1076 			// continue;
1077 		}
1078 		bytes = urb->iso_frame_desc[i].actual_length;
1079 		if (subs->stream_offset_adj > 0) {
1080 			unsigned int adj = min(subs->stream_offset_adj, bytes);
1081 			cp += adj;
1082 			bytes -= adj;
1083 			subs->stream_offset_adj -= adj;
1084 		}
1085 		frames = bytes / stride;
1086 		if (!subs->txfr_quirk)
1087 			bytes = frames * stride;
1088 		if (bytes % (runtime->sample_bits >> 3) != 0) {
1089 			int oldbytes = bytes;
1090 			bytes = frames * stride;
1091 			dev_warn_ratelimited(&subs->dev->dev,
1092 				 "Corrected urb data len. %d->%d\n",
1093 							oldbytes, bytes);
1094 		}
1095 		/* update the current pointer */
1096 		spin_lock_irqsave(&subs->lock, flags);
1097 		oldptr = subs->hwptr_done;
1098 		subs->hwptr_done += bytes;
1099 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1100 			subs->hwptr_done -= runtime->buffer_size * stride;
1101 		frames = (bytes + (oldptr % stride)) / stride;
1102 		subs->transfer_done += frames;
1103 		if (subs->transfer_done >= runtime->period_size) {
1104 			subs->transfer_done -= runtime->period_size;
1105 			period_elapsed = 1;
1106 		}
1107 		/* capture delay is by construction limited to one URB,
1108 		 * reset delays here
1109 		 */
1110 		runtime->delay = subs->last_delay = 0;
1111 
1112 		/* realign last_frame_number */
1113 		subs->last_frame_number = current_frame_number;
1114 		subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1115 
1116 		spin_unlock_irqrestore(&subs->lock, flags);
1117 		/* copy a data chunk */
1118 		if (oldptr + bytes > runtime->buffer_size * stride) {
1119 			unsigned int bytes1 =
1120 					runtime->buffer_size * stride - oldptr;
1121 			memcpy(runtime->dma_area + oldptr, cp, bytes1);
1122 			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
1123 		} else {
1124 			memcpy(runtime->dma_area + oldptr, cp, bytes);
1125 		}
1126 	}
1127 
1128 	if (period_elapsed)
1129 		snd_pcm_period_elapsed(subs->pcm_substream);
1130 }
1131 
1132 static inline void fill_playback_urb_dsd_dop(struct snd_usb_substream *subs,
1133 					     struct urb *urb, unsigned int bytes)
1134 {
1135 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1136 	unsigned int stride = runtime->frame_bits >> 3;
1137 	unsigned int dst_idx = 0;
1138 	unsigned int src_idx = subs->hwptr_done;
1139 	unsigned int wrap = runtime->buffer_size * stride;
1140 	u8 *dst = urb->transfer_buffer;
1141 	u8 *src = runtime->dma_area;
1142 	u8 marker[] = { 0x05, 0xfa };
1143 
1144 	/*
1145 	 * The DSP DOP format defines a way to transport DSD samples over
1146 	 * normal PCM data endpoints. It requires stuffing of marker bytes
1147 	 * (0x05 and 0xfa, alternating per sample frame), and then expects
1148 	 * 2 additional bytes of actual payload. The whole frame is stored
1149 	 * LSB.
1150 	 *
1151 	 * Hence, for a stereo transport, the buffer layout looks like this,
1152 	 * where L refers to left channel samples and R to right.
1153 	 *
1154 	 *   L1 L2 0x05   R1 R2 0x05   L3 L4 0xfa  R3 R4 0xfa
1155 	 *   L5 L6 0x05   R5 R6 0x05   L7 L8 0xfa  R7 R8 0xfa
1156 	 *   .....
1157 	 *
1158 	 */
1159 
1160 	while (bytes--) {
1161 		if (++subs->dsd_dop.byte_idx == 3) {
1162 			/* frame boundary? */
1163 			dst[dst_idx++] = marker[subs->dsd_dop.marker];
1164 			src_idx += 2;
1165 			subs->dsd_dop.byte_idx = 0;
1166 
1167 			if (++subs->dsd_dop.channel % runtime->channels == 0) {
1168 				/* alternate the marker */
1169 				subs->dsd_dop.marker++;
1170 				subs->dsd_dop.marker %= ARRAY_SIZE(marker);
1171 				subs->dsd_dop.channel = 0;
1172 			}
1173 		} else {
1174 			/* stuff the DSD payload */
1175 			int idx = (src_idx + subs->dsd_dop.byte_idx - 1) % wrap;
1176 
1177 			if (subs->cur_audiofmt->dsd_bitrev)
1178 				dst[dst_idx++] = bitrev8(src[idx]);
1179 			else
1180 				dst[dst_idx++] = src[idx];
1181 
1182 			subs->hwptr_done++;
1183 		}
1184 	}
1185 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1186 		subs->hwptr_done -= runtime->buffer_size * stride;
1187 }
1188 
1189 static void copy_to_urb(struct snd_usb_substream *subs, struct urb *urb,
1190 			int offset, int stride, unsigned int bytes)
1191 {
1192 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1193 
1194 	if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
1195 		/* err, the transferred area goes over buffer boundary. */
1196 		unsigned int bytes1 =
1197 			runtime->buffer_size * stride - subs->hwptr_done;
1198 		memcpy(urb->transfer_buffer + offset,
1199 		       runtime->dma_area + subs->hwptr_done, bytes1);
1200 		memcpy(urb->transfer_buffer + offset + bytes1,
1201 		       runtime->dma_area, bytes - bytes1);
1202 	} else {
1203 		memcpy(urb->transfer_buffer + offset,
1204 		       runtime->dma_area + subs->hwptr_done, bytes);
1205 	}
1206 	subs->hwptr_done += bytes;
1207 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1208 		subs->hwptr_done -= runtime->buffer_size * stride;
1209 }
1210 
1211 static unsigned int copy_to_urb_quirk(struct snd_usb_substream *subs,
1212 				      struct urb *urb, int stride,
1213 				      unsigned int bytes)
1214 {
1215 	__le32 packet_length;
1216 	int i;
1217 
1218 	/* Put __le32 length descriptor at start of each packet. */
1219 	for (i = 0; i < urb->number_of_packets; i++) {
1220 		unsigned int length = urb->iso_frame_desc[i].length;
1221 		unsigned int offset = urb->iso_frame_desc[i].offset;
1222 
1223 		packet_length = cpu_to_le32(length);
1224 		offset += i * sizeof(packet_length);
1225 		urb->iso_frame_desc[i].offset = offset;
1226 		urb->iso_frame_desc[i].length += sizeof(packet_length);
1227 		memcpy(urb->transfer_buffer + offset,
1228 		       &packet_length, sizeof(packet_length));
1229 		copy_to_urb(subs, urb, offset + sizeof(packet_length),
1230 			    stride, length);
1231 	}
1232 	/* Adjust transfer size accordingly. */
1233 	bytes += urb->number_of_packets * sizeof(packet_length);
1234 	return bytes;
1235 }
1236 
1237 static void prepare_playback_urb(struct snd_usb_substream *subs,
1238 				 struct urb *urb)
1239 {
1240 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1241 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1242 	struct snd_urb_ctx *ctx = urb->context;
1243 	unsigned int counts, frames, bytes;
1244 	int i, stride, period_elapsed = 0;
1245 	unsigned long flags;
1246 
1247 	stride = runtime->frame_bits >> 3;
1248 
1249 	frames = 0;
1250 	urb->number_of_packets = 0;
1251 	spin_lock_irqsave(&subs->lock, flags);
1252 	subs->frame_limit += ep->max_urb_frames;
1253 	for (i = 0; i < ctx->packets; i++) {
1254 		counts = snd_usb_endpoint_next_packet_size(ep, ctx, i);
1255 		/* set up descriptor */
1256 		urb->iso_frame_desc[i].offset = frames * ep->stride;
1257 		urb->iso_frame_desc[i].length = counts * ep->stride;
1258 		frames += counts;
1259 		urb->number_of_packets++;
1260 		subs->transfer_done += counts;
1261 		if (subs->transfer_done >= runtime->period_size) {
1262 			subs->transfer_done -= runtime->period_size;
1263 			subs->frame_limit = 0;
1264 			period_elapsed = 1;
1265 			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
1266 				if (subs->transfer_done > 0) {
1267 					/* FIXME: fill-max mode is not
1268 					 * supported yet */
1269 					frames -= subs->transfer_done;
1270 					counts -= subs->transfer_done;
1271 					urb->iso_frame_desc[i].length =
1272 						counts * ep->stride;
1273 					subs->transfer_done = 0;
1274 				}
1275 				i++;
1276 				if (i < ctx->packets) {
1277 					/* add a transfer delimiter */
1278 					urb->iso_frame_desc[i].offset =
1279 						frames * ep->stride;
1280 					urb->iso_frame_desc[i].length = 0;
1281 					urb->number_of_packets++;
1282 				}
1283 				break;
1284 			}
1285 		}
1286 		/* finish at the period boundary or after enough frames */
1287 		if ((period_elapsed ||
1288 				subs->transfer_done >= subs->frame_limit) &&
1289 		    !snd_usb_endpoint_implicit_feedback_sink(ep))
1290 			break;
1291 	}
1292 	bytes = frames * ep->stride;
1293 
1294 	if (unlikely(ep->cur_format == SNDRV_PCM_FORMAT_DSD_U16_LE &&
1295 		     subs->cur_audiofmt->dsd_dop)) {
1296 		fill_playback_urb_dsd_dop(subs, urb, bytes);
1297 	} else if (unlikely(ep->cur_format == SNDRV_PCM_FORMAT_DSD_U8 &&
1298 			   subs->cur_audiofmt->dsd_bitrev)) {
1299 		/* bit-reverse the bytes */
1300 		u8 *buf = urb->transfer_buffer;
1301 		for (i = 0; i < bytes; i++) {
1302 			int idx = (subs->hwptr_done + i)
1303 				% (runtime->buffer_size * stride);
1304 			buf[i] = bitrev8(runtime->dma_area[idx]);
1305 		}
1306 
1307 		subs->hwptr_done += bytes;
1308 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1309 			subs->hwptr_done -= runtime->buffer_size * stride;
1310 	} else {
1311 		/* usual PCM */
1312 		if (!subs->tx_length_quirk)
1313 			copy_to_urb(subs, urb, 0, stride, bytes);
1314 		else
1315 			bytes = copy_to_urb_quirk(subs, urb, stride, bytes);
1316 			/* bytes is now amount of outgoing data */
1317 	}
1318 
1319 	/* update delay with exact number of samples queued */
1320 	runtime->delay = subs->last_delay;
1321 	runtime->delay += frames;
1322 	subs->last_delay = runtime->delay;
1323 
1324 	/* realign last_frame_number */
1325 	subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1326 	subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1327 
1328 	if (subs->trigger_tstamp_pending_update) {
1329 		/* this is the first actual URB submitted,
1330 		 * update trigger timestamp to reflect actual start time
1331 		 */
1332 		snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
1333 		subs->trigger_tstamp_pending_update = false;
1334 	}
1335 
1336 	spin_unlock_irqrestore(&subs->lock, flags);
1337 	urb->transfer_buffer_length = bytes;
1338 	if (period_elapsed)
1339 		snd_pcm_period_elapsed(subs->pcm_substream);
1340 }
1341 
1342 /*
1343  * process after playback data complete
1344  * - decrease the delay count again
1345  */
1346 static void retire_playback_urb(struct snd_usb_substream *subs,
1347 			       struct urb *urb)
1348 {
1349 	unsigned long flags;
1350 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1351 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1352 	int processed = urb->transfer_buffer_length / ep->stride;
1353 	int est_delay;
1354 
1355 	/* ignore the delay accounting when processed=0 is given, i.e.
1356 	 * silent payloads are processed before handling the actual data
1357 	 */
1358 	if (!processed)
1359 		return;
1360 
1361 	spin_lock_irqsave(&subs->lock, flags);
1362 	if (!subs->last_delay)
1363 		goto out; /* short path */
1364 
1365 	est_delay = snd_usb_pcm_delay(subs, runtime->rate);
1366 	/* update delay with exact number of samples played */
1367 	if (processed > subs->last_delay)
1368 		subs->last_delay = 0;
1369 	else
1370 		subs->last_delay -= processed;
1371 	runtime->delay = subs->last_delay;
1372 
1373 	/*
1374 	 * Report when delay estimate is off by more than 2ms.
1375 	 * The error should be lower than 2ms since the estimate relies
1376 	 * on two reads of a counter updated every ms.
1377 	 */
1378 	if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
1379 		dev_dbg_ratelimited(&subs->dev->dev,
1380 			"delay: estimated %d, actual %d\n",
1381 			est_delay, subs->last_delay);
1382 
1383 	if (!subs->running) {
1384 		/* update last_frame_number for delay counting here since
1385 		 * prepare_playback_urb won't be called during pause
1386 		 */
1387 		subs->last_frame_number =
1388 			usb_get_current_frame_number(subs->dev) & 0xff;
1389 	}
1390 
1391  out:
1392 	spin_unlock_irqrestore(&subs->lock, flags);
1393 }
1394 
1395 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream,
1396 					      int cmd)
1397 {
1398 	struct snd_usb_substream *subs = substream->runtime->private_data;
1399 
1400 	switch (cmd) {
1401 	case SNDRV_PCM_TRIGGER_START:
1402 		subs->trigger_tstamp_pending_update = true;
1403 		fallthrough;
1404 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1405 		snd_usb_endpoint_set_callback(subs->data_endpoint,
1406 					      prepare_playback_urb,
1407 					      retire_playback_urb,
1408 					      subs);
1409 		subs->running = 1;
1410 		dev_dbg(&subs->dev->dev, "%d:%d Start Playback PCM\n",
1411 			subs->cur_audiofmt->iface,
1412 			subs->cur_audiofmt->altsetting);
1413 		return 0;
1414 	case SNDRV_PCM_TRIGGER_SUSPEND:
1415 	case SNDRV_PCM_TRIGGER_STOP:
1416 		stop_endpoints(subs);
1417 		snd_usb_endpoint_set_callback(subs->data_endpoint,
1418 					      NULL, NULL, NULL);
1419 		subs->running = 0;
1420 		dev_dbg(&subs->dev->dev, "%d:%d Stop Playback PCM\n",
1421 			subs->cur_audiofmt->iface,
1422 			subs->cur_audiofmt->altsetting);
1423 		return 0;
1424 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1425 		/* keep retire_data_urb for delay calculation */
1426 		snd_usb_endpoint_set_callback(subs->data_endpoint,
1427 					      NULL,
1428 					      retire_playback_urb,
1429 					      subs);
1430 		subs->running = 0;
1431 		dev_dbg(&subs->dev->dev, "%d:%d Pause Playback PCM\n",
1432 			subs->cur_audiofmt->iface,
1433 			subs->cur_audiofmt->altsetting);
1434 		return 0;
1435 	}
1436 
1437 	return -EINVAL;
1438 }
1439 
1440 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream,
1441 					     int cmd)
1442 {
1443 	int err;
1444 	struct snd_usb_substream *subs = substream->runtime->private_data;
1445 
1446 	switch (cmd) {
1447 	case SNDRV_PCM_TRIGGER_START:
1448 		err = start_endpoints(subs);
1449 		if (err < 0)
1450 			return err;
1451 		fallthrough;
1452 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1453 		snd_usb_endpoint_set_callback(subs->data_endpoint,
1454 					      NULL, retire_capture_urb,
1455 					      subs);
1456 		subs->running = 1;
1457 		dev_dbg(&subs->dev->dev, "%d:%d Start Capture PCM\n",
1458 			subs->cur_audiofmt->iface,
1459 			subs->cur_audiofmt->altsetting);
1460 		return 0;
1461 	case SNDRV_PCM_TRIGGER_SUSPEND:
1462 	case SNDRV_PCM_TRIGGER_STOP:
1463 		stop_endpoints(subs);
1464 		fallthrough;
1465 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1466 		snd_usb_endpoint_set_callback(subs->data_endpoint,
1467 					      NULL, NULL, NULL);
1468 		subs->running = 0;
1469 		dev_dbg(&subs->dev->dev, "%d:%d Stop Capture PCM\n",
1470 			subs->cur_audiofmt->iface,
1471 			subs->cur_audiofmt->altsetting);
1472 		return 0;
1473 	}
1474 
1475 	return -EINVAL;
1476 }
1477 
1478 static const struct snd_pcm_ops snd_usb_playback_ops = {
1479 	.open =		snd_usb_pcm_open,
1480 	.close =	snd_usb_pcm_close,
1481 	.hw_params =	snd_usb_hw_params,
1482 	.hw_free =	snd_usb_hw_free,
1483 	.prepare =	snd_usb_pcm_prepare,
1484 	.trigger =	snd_usb_substream_playback_trigger,
1485 	.sync_stop =	snd_usb_pcm_sync_stop,
1486 	.pointer =	snd_usb_pcm_pointer,
1487 };
1488 
1489 static const struct snd_pcm_ops snd_usb_capture_ops = {
1490 	.open =		snd_usb_pcm_open,
1491 	.close =	snd_usb_pcm_close,
1492 	.hw_params =	snd_usb_hw_params,
1493 	.hw_free =	snd_usb_hw_free,
1494 	.prepare =	snd_usb_pcm_prepare,
1495 	.trigger =	snd_usb_substream_capture_trigger,
1496 	.sync_stop =	snd_usb_pcm_sync_stop,
1497 	.pointer =	snd_usb_pcm_pointer,
1498 };
1499 
1500 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
1501 {
1502 	const struct snd_pcm_ops *ops;
1503 
1504 	ops = stream == SNDRV_PCM_STREAM_PLAYBACK ?
1505 			&snd_usb_playback_ops : &snd_usb_capture_ops;
1506 	snd_pcm_set_ops(pcm, stream, ops);
1507 }
1508 
1509 void snd_usb_preallocate_buffer(struct snd_usb_substream *subs)
1510 {
1511 	struct snd_pcm *pcm = subs->stream->pcm;
1512 	struct snd_pcm_substream *s = pcm->streams[subs->direction].substream;
1513 	struct device *dev = subs->dev->bus->controller;
1514 
1515 	if (snd_usb_use_vmalloc)
1516 		snd_pcm_set_managed_buffer(s, SNDRV_DMA_TYPE_VMALLOC,
1517 					   NULL, 0, 0);
1518 	else
1519 		snd_pcm_set_managed_buffer(s, SNDRV_DMA_TYPE_DEV_SG,
1520 					   dev, 64*1024, 512*1024);
1521 }
1522