xref: /openbmc/linux/sound/usb/pcm.c (revision b5f184fbdb03b4fcc1141de34dd5ec964ca5d99e)
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 	sync_pending_stops(subs);
274 	return 0;
275 }
276 
277 /* Set up sync endpoint */
278 int snd_usb_audioformat_set_sync_ep(struct snd_usb_audio *chip,
279 				    struct audioformat *fmt)
280 {
281 	struct usb_device *dev = chip->dev;
282 	struct usb_host_interface *alts;
283 	struct usb_interface_descriptor *altsd;
284 	unsigned int ep, attr, sync_attr;
285 	bool is_playback;
286 	int err;
287 
288 	alts = snd_usb_get_host_interface(chip, fmt->iface, fmt->altsetting);
289 	if (!alts)
290 		return 0;
291 	altsd = get_iface_desc(alts);
292 
293 	err = snd_usb_parse_implicit_fb_quirk(chip, fmt, alts);
294 	if (err > 0)
295 		return 0; /* matched */
296 
297 	/*
298 	 * Generic sync EP handling
299 	 */
300 
301 	if (altsd->bNumEndpoints < 2)
302 		return 0;
303 
304 	is_playback = !(get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN);
305 	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
306 	if ((is_playback && (attr == USB_ENDPOINT_SYNC_SYNC ||
307 			     attr == USB_ENDPOINT_SYNC_ADAPTIVE)) ||
308 	    (!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE))
309 		return 0;
310 
311 	sync_attr = get_endpoint(alts, 1)->bmAttributes;
312 
313 	/*
314 	 * In case of illegal SYNC_NONE for OUT endpoint, we keep going to see
315 	 * if we don't find a sync endpoint, as on M-Audio Transit. In case of
316 	 * error fall back to SYNC mode and don't create sync endpoint
317 	 */
318 
319 	/* check sync-pipe endpoint */
320 	/* ... and check descriptor size before accessing bSynchAddress
321 	   because there is a version of the SB Audigy 2 NX firmware lacking
322 	   the audio fields in the endpoint descriptors */
323 	if ((sync_attr & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC ||
324 	    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
325 	     get_endpoint(alts, 1)->bSynchAddress != 0)) {
326 		dev_err(&dev->dev,
327 			"%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
328 			   fmt->iface, fmt->altsetting,
329 			   get_endpoint(alts, 1)->bmAttributes,
330 			   get_endpoint(alts, 1)->bLength,
331 			   get_endpoint(alts, 1)->bSynchAddress);
332 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
333 			return 0;
334 		return -EINVAL;
335 	}
336 	ep = get_endpoint(alts, 1)->bEndpointAddress;
337 	if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
338 	    get_endpoint(alts, 0)->bSynchAddress != 0 &&
339 	    ((is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
340 	     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
341 		dev_err(&dev->dev,
342 			"%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
343 			   fmt->iface, fmt->altsetting,
344 			   is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
345 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
346 			return 0;
347 		return -EINVAL;
348 	}
349 
350 	fmt->sync_ep = ep;
351 	fmt->sync_iface = altsd->bInterfaceNumber;
352 	fmt->sync_altsetting = altsd->bAlternateSetting;
353 	fmt->sync_ep_idx = 1;
354 	if ((sync_attr & USB_ENDPOINT_USAGE_MASK) == USB_ENDPOINT_USAGE_IMPLICIT_FB)
355 		fmt->implicit_fb = 1;
356 
357 	dev_dbg(&dev->dev, "%d:%d: found sync_ep=0x%x, iface=%d, alt=%d, implicit_fb=%d\n",
358 		fmt->iface, fmt->altsetting, fmt->sync_ep, fmt->sync_iface,
359 		fmt->sync_altsetting, fmt->implicit_fb);
360 
361 	return 0;
362 }
363 
364 static int snd_usb_pcm_change_state(struct snd_usb_substream *subs, int state)
365 {
366 	int ret;
367 
368 	if (!subs->str_pd)
369 		return 0;
370 
371 	ret = snd_usb_power_domain_set(subs->stream->chip, subs->str_pd, state);
372 	if (ret < 0) {
373 		dev_err(&subs->dev->dev,
374 			"Cannot change Power Domain ID: %d to state: %d. Err: %d\n",
375 			subs->str_pd->pd_id, state, ret);
376 		return ret;
377 	}
378 
379 	return 0;
380 }
381 
382 int snd_usb_pcm_suspend(struct snd_usb_stream *as)
383 {
384 	int ret;
385 
386 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D2);
387 	if (ret < 0)
388 		return ret;
389 
390 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D2);
391 	if (ret < 0)
392 		return ret;
393 
394 	return 0;
395 }
396 
397 int snd_usb_pcm_resume(struct snd_usb_stream *as)
398 {
399 	int ret;
400 
401 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D1);
402 	if (ret < 0)
403 		return ret;
404 
405 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D1);
406 	if (ret < 0)
407 		return ret;
408 
409 	return 0;
410 }
411 
412 static void close_endpoints(struct snd_usb_audio *chip,
413 			    struct snd_usb_substream *subs)
414 {
415 	if (subs->data_endpoint) {
416 		snd_usb_endpoint_set_sync(chip, subs->data_endpoint, NULL);
417 		snd_usb_endpoint_close(chip, subs->data_endpoint);
418 		subs->data_endpoint = NULL;
419 	}
420 
421 	if (subs->sync_endpoint) {
422 		snd_usb_endpoint_close(chip, subs->sync_endpoint);
423 		subs->sync_endpoint = NULL;
424 	}
425 }
426 
427 static int configure_endpoints(struct snd_usb_audio *chip,
428 			       struct snd_usb_substream *subs)
429 {
430 	int err;
431 
432 	if (subs->data_endpoint->need_setup) {
433 		/* stop any running stream beforehand */
434 		if (stop_endpoints(subs))
435 			sync_pending_stops(subs);
436 		err = snd_usb_endpoint_configure(chip, subs->data_endpoint);
437 		if (err < 0)
438 			return err;
439 		snd_usb_set_format_quirk(subs, subs->cur_audiofmt);
440 	}
441 
442 	if (subs->sync_endpoint) {
443 		err = snd_usb_endpoint_configure(chip, subs->sync_endpoint);
444 		if (err < 0)
445 			return err;
446 	}
447 
448 	return 0;
449 }
450 
451 /*
452  * hw_params callback
453  *
454  * allocate a buffer and set the given audio format.
455  *
456  * so far we use a physically linear buffer although packetize transfer
457  * doesn't need a continuous area.
458  * if sg buffer is supported on the later version of alsa, we'll follow
459  * that.
460  */
461 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
462 			     struct snd_pcm_hw_params *hw_params)
463 {
464 	struct snd_usb_substream *subs = substream->runtime->private_data;
465 	struct snd_usb_audio *chip = subs->stream->chip;
466 	const struct audioformat *fmt;
467 	const struct audioformat *sync_fmt;
468 	int ret;
469 
470 	ret = snd_media_start_pipeline(subs);
471 	if (ret)
472 		return ret;
473 
474 	fmt = find_substream_format(subs, hw_params);
475 	if (!fmt) {
476 		usb_audio_dbg(chip,
477 			      "cannot find format: format=%s, rate=%d, channels=%d\n",
478 			      snd_pcm_format_name(params_format(hw_params)),
479 			      params_rate(hw_params), params_channels(hw_params));
480 		ret = -EINVAL;
481 		goto stop_pipeline;
482 	}
483 
484 	if (fmt->implicit_fb) {
485 		sync_fmt = snd_usb_find_implicit_fb_sync_format(chip, fmt,
486 								hw_params,
487 								!substream->stream);
488 		if (!sync_fmt) {
489 			usb_audio_dbg(chip,
490 				      "cannot find sync format: ep=0x%x, iface=%d:%d, format=%s, rate=%d, channels=%d\n",
491 				      fmt->sync_ep, fmt->sync_iface,
492 				      fmt->sync_altsetting,
493 				      snd_pcm_format_name(params_format(hw_params)),
494 				      params_rate(hw_params), params_channels(hw_params));
495 			ret = -EINVAL;
496 			goto stop_pipeline;
497 		}
498 	} else {
499 		sync_fmt = fmt;
500 	}
501 
502 	ret = snd_usb_lock_shutdown(chip);
503 	if (ret < 0)
504 		goto stop_pipeline;
505 
506 	ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
507 	if (ret < 0)
508 		goto unlock;
509 
510 	if (subs->data_endpoint) {
511 		if (snd_usb_endpoint_compatible(chip, subs->data_endpoint,
512 						fmt, hw_params))
513 			goto unlock;
514 		close_endpoints(chip, subs);
515 	}
516 
517 	subs->data_endpoint = snd_usb_endpoint_open(chip, fmt, hw_params, false);
518 	if (!subs->data_endpoint) {
519 		ret = -EINVAL;
520 		goto unlock;
521 	}
522 
523 	if (fmt->sync_ep) {
524 		subs->sync_endpoint = snd_usb_endpoint_open(chip, sync_fmt,
525 							    hw_params,
526 							    fmt == sync_fmt);
527 		if (!subs->sync_endpoint) {
528 			ret = -EINVAL;
529 			goto unlock;
530 		}
531 
532 		snd_usb_endpoint_set_sync(chip, subs->data_endpoint,
533 					  subs->sync_endpoint);
534 	}
535 
536 	mutex_lock(&chip->mutex);
537 	subs->cur_audiofmt = fmt;
538 	mutex_unlock(&chip->mutex);
539 
540 	ret = configure_endpoints(chip, subs);
541 
542  unlock:
543 	if (ret < 0)
544 		close_endpoints(chip, subs);
545 
546 	snd_usb_unlock_shutdown(chip);
547  stop_pipeline:
548 	if (ret < 0)
549 		snd_media_stop_pipeline(subs);
550 
551 	return ret;
552 }
553 
554 /*
555  * hw_free callback
556  *
557  * reset the audio format and release the buffer
558  */
559 static int snd_usb_hw_free(struct snd_pcm_substream *substream)
560 {
561 	struct snd_usb_substream *subs = substream->runtime->private_data;
562 	struct snd_usb_audio *chip = subs->stream->chip;
563 
564 	snd_media_stop_pipeline(subs);
565 	mutex_lock(&chip->mutex);
566 	subs->cur_audiofmt = NULL;
567 	mutex_unlock(&chip->mutex);
568 	if (!snd_usb_lock_shutdown(chip)) {
569 		if (stop_endpoints(subs))
570 			sync_pending_stops(subs);
571 		close_endpoints(chip, subs);
572 		snd_usb_unlock_shutdown(chip);
573 	}
574 
575 	return 0;
576 }
577 
578 /*
579  * prepare callback
580  *
581  * only a few subtle things...
582  */
583 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
584 {
585 	struct snd_pcm_runtime *runtime = substream->runtime;
586 	struct snd_usb_substream *subs = runtime->private_data;
587 	struct snd_usb_audio *chip = subs->stream->chip;
588 	int ret;
589 
590 	ret = snd_usb_lock_shutdown(chip);
591 	if (ret < 0)
592 		return ret;
593 	if (snd_BUG_ON(!subs->data_endpoint)) {
594 		ret = -EIO;
595 		goto unlock;
596 	}
597 
598 	ret = configure_endpoints(chip, subs);
599 	if (ret < 0)
600 		goto unlock;
601 
602 	/* reset the pointer */
603 	subs->hwptr_done = 0;
604 	subs->transfer_done = 0;
605 	subs->last_delay = 0;
606 	subs->last_frame_number = 0;
607 	runtime->delay = 0;
608 
609 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
610 	 * updates for all URBs would happen at the same time when starting */
611 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
612 		ret = start_endpoints(subs);
613 
614  unlock:
615 	snd_usb_unlock_shutdown(chip);
616 	return ret;
617 }
618 
619 /*
620  * h/w constraints
621  */
622 
623 #ifdef HW_CONST_DEBUG
624 #define hwc_debug(fmt, args...) pr_debug(fmt, ##args)
625 #else
626 #define hwc_debug(fmt, args...) do { } while(0)
627 #endif
628 
629 static const struct snd_pcm_hardware snd_usb_hardware =
630 {
631 	.info =			SNDRV_PCM_INFO_MMAP |
632 				SNDRV_PCM_INFO_MMAP_VALID |
633 				SNDRV_PCM_INFO_BATCH |
634 				SNDRV_PCM_INFO_INTERLEAVED |
635 				SNDRV_PCM_INFO_BLOCK_TRANSFER |
636 				SNDRV_PCM_INFO_PAUSE,
637 	.channels_min =		1,
638 	.channels_max =		256,
639 	.buffer_bytes_max =	1024 * 1024,
640 	.period_bytes_min =	64,
641 	.period_bytes_max =	512 * 1024,
642 	.periods_min =		2,
643 	.periods_max =		1024,
644 };
645 
646 static int hw_check_valid_format(struct snd_usb_substream *subs,
647 				 struct snd_pcm_hw_params *params,
648 				 const struct audioformat *fp)
649 {
650 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
651 	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
652 	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
653 	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
654 	struct snd_mask check_fmts;
655 	unsigned int ptime;
656 
657 	/* check the format */
658 	snd_mask_none(&check_fmts);
659 	check_fmts.bits[0] = (u32)fp->formats;
660 	check_fmts.bits[1] = (u32)(fp->formats >> 32);
661 	snd_mask_intersect(&check_fmts, fmts);
662 	if (snd_mask_empty(&check_fmts)) {
663 		hwc_debug("   > check: no supported format 0x%llx\n", fp->formats);
664 		return 0;
665 	}
666 	/* check the channels */
667 	if (fp->channels < ct->min || fp->channels > ct->max) {
668 		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
669 		return 0;
670 	}
671 	/* check the rate is within the range */
672 	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
673 		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
674 		return 0;
675 	}
676 	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
677 		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
678 		return 0;
679 	}
680 	/* check whether the period time is >= the data packet interval */
681 	if (subs->speed != USB_SPEED_FULL) {
682 		ptime = 125 * (1 << fp->datainterval);
683 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
684 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
685 			return 0;
686 		}
687 	}
688 	return 1;
689 }
690 
691 static int apply_hw_params_minmax(struct snd_interval *it, unsigned int rmin,
692 				  unsigned int rmax)
693 {
694 	int changed;
695 
696 	if (rmin > rmax) {
697 		hwc_debug("  --> get empty\n");
698 		it->empty = 1;
699 		return -EINVAL;
700 	}
701 
702 	changed = 0;
703 	if (it->min < rmin) {
704 		it->min = rmin;
705 		it->openmin = 0;
706 		changed = 1;
707 	}
708 	if (it->max > rmax) {
709 		it->max = rmax;
710 		it->openmax = 0;
711 		changed = 1;
712 	}
713 	if (snd_interval_checkempty(it)) {
714 		it->empty = 1;
715 		return -EINVAL;
716 	}
717 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
718 	return changed;
719 }
720 
721 static int hw_rule_rate(struct snd_pcm_hw_params *params,
722 			struct snd_pcm_hw_rule *rule)
723 {
724 	struct snd_usb_substream *subs = rule->private;
725 	const struct audioformat *fp;
726 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
727 	unsigned int rmin, rmax, r;
728 	int i;
729 
730 	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
731 	rmin = UINT_MAX;
732 	rmax = 0;
733 	list_for_each_entry(fp, &subs->fmt_list, list) {
734 		if (!hw_check_valid_format(subs, params, fp))
735 			continue;
736 		if (fp->rate_table && fp->nr_rates) {
737 			for (i = 0; i < fp->nr_rates; i++) {
738 				r = fp->rate_table[i];
739 				if (!snd_interval_test(it, r))
740 					continue;
741 				rmin = min(rmin, r);
742 				rmax = max(rmax, r);
743 			}
744 		} else {
745 			rmin = min(rmin, fp->rate_min);
746 			rmax = max(rmax, fp->rate_max);
747 		}
748 	}
749 
750 	return apply_hw_params_minmax(it, rmin, rmax);
751 }
752 
753 
754 static int hw_rule_channels(struct snd_pcm_hw_params *params,
755 			    struct snd_pcm_hw_rule *rule)
756 {
757 	struct snd_usb_substream *subs = rule->private;
758 	const struct audioformat *fp;
759 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
760 	unsigned int rmin, rmax;
761 
762 	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
763 	rmin = UINT_MAX;
764 	rmax = 0;
765 	list_for_each_entry(fp, &subs->fmt_list, list) {
766 		if (!hw_check_valid_format(subs, params, fp))
767 			continue;
768 		rmin = min(rmin, fp->channels);
769 		rmax = max(rmax, fp->channels);
770 	}
771 
772 	return apply_hw_params_minmax(it, rmin, rmax);
773 }
774 
775 static int apply_hw_params_format_bits(struct snd_mask *fmt, u64 fbits)
776 {
777 	u32 oldbits[2];
778 	int changed;
779 
780 	oldbits[0] = fmt->bits[0];
781 	oldbits[1] = fmt->bits[1];
782 	fmt->bits[0] &= (u32)fbits;
783 	fmt->bits[1] &= (u32)(fbits >> 32);
784 	if (!fmt->bits[0] && !fmt->bits[1]) {
785 		hwc_debug("  --> get empty\n");
786 		return -EINVAL;
787 	}
788 	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
789 	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
790 	return changed;
791 }
792 
793 static int hw_rule_format(struct snd_pcm_hw_params *params,
794 			  struct snd_pcm_hw_rule *rule)
795 {
796 	struct snd_usb_substream *subs = rule->private;
797 	const struct audioformat *fp;
798 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
799 	u64 fbits;
800 
801 	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
802 	fbits = 0;
803 	list_for_each_entry(fp, &subs->fmt_list, list) {
804 		if (!hw_check_valid_format(subs, params, fp))
805 			continue;
806 		fbits |= fp->formats;
807 	}
808 	return apply_hw_params_format_bits(fmt, fbits);
809 }
810 
811 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
812 			       struct snd_pcm_hw_rule *rule)
813 {
814 	struct snd_usb_substream *subs = rule->private;
815 	const struct audioformat *fp;
816 	struct snd_interval *it;
817 	unsigned char min_datainterval;
818 	unsigned int pmin;
819 
820 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
821 	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
822 	min_datainterval = 0xff;
823 	list_for_each_entry(fp, &subs->fmt_list, list) {
824 		if (!hw_check_valid_format(subs, params, fp))
825 			continue;
826 		min_datainterval = min(min_datainterval, fp->datainterval);
827 	}
828 	if (min_datainterval == 0xff) {
829 		hwc_debug("  --> get empty\n");
830 		it->empty = 1;
831 		return -EINVAL;
832 	}
833 	pmin = 125 * (1 << min_datainterval);
834 
835 	return apply_hw_params_minmax(it, pmin, UINT_MAX);
836 }
837 
838 /* get the EP or the sync EP for implicit fb when it's already set up */
839 static const struct snd_usb_endpoint *
840 get_sync_ep_from_substream(struct snd_usb_substream *subs)
841 {
842 	struct snd_usb_audio *chip = subs->stream->chip;
843 	const struct audioformat *fp;
844 	const struct snd_usb_endpoint *ep;
845 
846 	list_for_each_entry(fp, &subs->fmt_list, list) {
847 		ep = snd_usb_get_endpoint(chip, fp->endpoint);
848 		if (ep && ep->cur_rate)
849 			return ep;
850 		if (!fp->implicit_fb)
851 			continue;
852 		/* for the implicit fb, check the sync ep as well */
853 		ep = snd_usb_get_endpoint(chip, fp->sync_ep);
854 		if (ep && ep->cur_rate)
855 			return ep;
856 	}
857 	return NULL;
858 }
859 
860 /* additional hw constraints for implicit feedback mode */
861 static int hw_rule_format_implicit_fb(struct snd_pcm_hw_params *params,
862 				      struct snd_pcm_hw_rule *rule)
863 {
864 	struct snd_usb_substream *subs = rule->private;
865 	const struct snd_usb_endpoint *ep;
866 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
867 
868 	ep = get_sync_ep_from_substream(subs);
869 	if (!ep)
870 		return 0;
871 
872 	hwc_debug("applying %s\n", __func__);
873 	return apply_hw_params_format_bits(fmt, pcm_format_to_bits(ep->cur_format));
874 }
875 
876 static int hw_rule_rate_implicit_fb(struct snd_pcm_hw_params *params,
877 				    struct snd_pcm_hw_rule *rule)
878 {
879 	struct snd_usb_substream *subs = rule->private;
880 	const struct snd_usb_endpoint *ep;
881 	struct snd_interval *it;
882 
883 	ep = get_sync_ep_from_substream(subs);
884 	if (!ep)
885 		return 0;
886 
887 	hwc_debug("applying %s\n", __func__);
888 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
889 	return apply_hw_params_minmax(it, ep->cur_rate, ep->cur_rate);
890 }
891 
892 static int hw_rule_period_size_implicit_fb(struct snd_pcm_hw_params *params,
893 					   struct snd_pcm_hw_rule *rule)
894 {
895 	struct snd_usb_substream *subs = rule->private;
896 	const struct snd_usb_endpoint *ep;
897 	struct snd_interval *it;
898 
899 	ep = get_sync_ep_from_substream(subs);
900 	if (!ep)
901 		return 0;
902 
903 	hwc_debug("applying %s\n", __func__);
904 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
905 	return apply_hw_params_minmax(it, ep->cur_period_frames,
906 				      ep->cur_period_frames);
907 }
908 
909 static int hw_rule_periods_implicit_fb(struct snd_pcm_hw_params *params,
910 				       struct snd_pcm_hw_rule *rule)
911 {
912 	struct snd_usb_substream *subs = rule->private;
913 	const struct snd_usb_endpoint *ep;
914 	struct snd_interval *it;
915 
916 	ep = get_sync_ep_from_substream(subs);
917 	if (!ep)
918 		return 0;
919 
920 	hwc_debug("applying %s\n", __func__);
921 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIODS);
922 	return apply_hw_params_minmax(it, ep->cur_buffer_periods,
923 				      ep->cur_buffer_periods);
924 }
925 
926 /*
927  * set up the runtime hardware information.
928  */
929 
930 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
931 {
932 	const struct audioformat *fp;
933 	unsigned int pt, ptmin;
934 	int param_period_time_if_needed = -1;
935 	int err;
936 
937 	runtime->hw.formats = subs->formats;
938 
939 	runtime->hw.rate_min = 0x7fffffff;
940 	runtime->hw.rate_max = 0;
941 	runtime->hw.channels_min = 256;
942 	runtime->hw.channels_max = 0;
943 	runtime->hw.rates = 0;
944 	ptmin = UINT_MAX;
945 	/* check min/max rates and channels */
946 	list_for_each_entry(fp, &subs->fmt_list, list) {
947 		runtime->hw.rates |= fp->rates;
948 		if (runtime->hw.rate_min > fp->rate_min)
949 			runtime->hw.rate_min = fp->rate_min;
950 		if (runtime->hw.rate_max < fp->rate_max)
951 			runtime->hw.rate_max = fp->rate_max;
952 		if (runtime->hw.channels_min > fp->channels)
953 			runtime->hw.channels_min = fp->channels;
954 		if (runtime->hw.channels_max < fp->channels)
955 			runtime->hw.channels_max = fp->channels;
956 		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
957 			/* FIXME: there might be more than one audio formats... */
958 			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
959 				fp->frame_size;
960 		}
961 		pt = 125 * (1 << fp->datainterval);
962 		ptmin = min(ptmin, pt);
963 	}
964 
965 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
966 	if (subs->speed == USB_SPEED_FULL)
967 		/* full speed devices have fixed data packet interval */
968 		ptmin = 1000;
969 	if (ptmin == 1000)
970 		/* if period time doesn't go below 1 ms, no rules needed */
971 		param_period_time_if_needed = -1;
972 
973 	err = snd_pcm_hw_constraint_minmax(runtime,
974 					   SNDRV_PCM_HW_PARAM_PERIOD_TIME,
975 					   ptmin, UINT_MAX);
976 	if (err < 0)
977 		return err;
978 
979 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
980 				  hw_rule_rate, subs,
981 				  SNDRV_PCM_HW_PARAM_RATE,
982 				  SNDRV_PCM_HW_PARAM_FORMAT,
983 				  SNDRV_PCM_HW_PARAM_CHANNELS,
984 				  param_period_time_if_needed,
985 				  -1);
986 	if (err < 0)
987 		return err;
988 
989 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
990 				  hw_rule_channels, subs,
991 				  SNDRV_PCM_HW_PARAM_CHANNELS,
992 				  SNDRV_PCM_HW_PARAM_FORMAT,
993 				  SNDRV_PCM_HW_PARAM_RATE,
994 				  param_period_time_if_needed,
995 				  -1);
996 	if (err < 0)
997 		return err;
998 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
999 				  hw_rule_format, subs,
1000 				  SNDRV_PCM_HW_PARAM_FORMAT,
1001 				  SNDRV_PCM_HW_PARAM_RATE,
1002 				  SNDRV_PCM_HW_PARAM_CHANNELS,
1003 				  param_period_time_if_needed,
1004 				  -1);
1005 	if (err < 0)
1006 		return err;
1007 	if (param_period_time_if_needed >= 0) {
1008 		err = snd_pcm_hw_rule_add(runtime, 0,
1009 					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1010 					  hw_rule_period_time, subs,
1011 					  SNDRV_PCM_HW_PARAM_FORMAT,
1012 					  SNDRV_PCM_HW_PARAM_CHANNELS,
1013 					  SNDRV_PCM_HW_PARAM_RATE,
1014 					  -1);
1015 		if (err < 0)
1016 			return err;
1017 	}
1018 
1019 	/* additional hw constraints for implicit fb */
1020 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
1021 				  hw_rule_format_implicit_fb, subs,
1022 				  SNDRV_PCM_HW_PARAM_FORMAT, -1);
1023 	if (err < 0)
1024 		return err;
1025 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1026 				  hw_rule_rate_implicit_fb, subs,
1027 				  SNDRV_PCM_HW_PARAM_RATE, -1);
1028 	if (err < 0)
1029 		return err;
1030 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
1031 				  hw_rule_period_size_implicit_fb, subs,
1032 				  SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
1033 	if (err < 0)
1034 		return err;
1035 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIODS,
1036 				  hw_rule_periods_implicit_fb, subs,
1037 				  SNDRV_PCM_HW_PARAM_PERIODS, -1);
1038 	if (err < 0)
1039 		return err;
1040 
1041 	return 0;
1042 }
1043 
1044 static int snd_usb_pcm_open(struct snd_pcm_substream *substream)
1045 {
1046 	int direction = substream->stream;
1047 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1048 	struct snd_pcm_runtime *runtime = substream->runtime;
1049 	struct snd_usb_substream *subs = &as->substream[direction];
1050 	int ret;
1051 
1052 	runtime->hw = snd_usb_hardware;
1053 	runtime->private_data = subs;
1054 	subs->pcm_substream = substream;
1055 	/* runtime PM is also done there */
1056 
1057 	/* initialize DSD/DOP context */
1058 	subs->dsd_dop.byte_idx = 0;
1059 	subs->dsd_dop.channel = 0;
1060 	subs->dsd_dop.marker = 1;
1061 
1062 	ret = setup_hw_info(runtime, subs);
1063 	if (ret < 0)
1064 		return ret;
1065 	ret = snd_usb_autoresume(subs->stream->chip);
1066 	if (ret < 0)
1067 		return ret;
1068 	ret = snd_media_stream_init(subs, as->pcm, direction);
1069 	if (ret < 0)
1070 		snd_usb_autosuspend(subs->stream->chip);
1071 	return ret;
1072 }
1073 
1074 static int snd_usb_pcm_close(struct snd_pcm_substream *substream)
1075 {
1076 	int direction = substream->stream;
1077 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1078 	struct snd_usb_substream *subs = &as->substream[direction];
1079 	int ret;
1080 
1081 	snd_media_stop_pipeline(subs);
1082 
1083 	if (!snd_usb_lock_shutdown(subs->stream->chip)) {
1084 		ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D1);
1085 		snd_usb_unlock_shutdown(subs->stream->chip);
1086 		if (ret < 0)
1087 			return ret;
1088 	}
1089 
1090 	subs->pcm_substream = NULL;
1091 	snd_usb_autosuspend(subs->stream->chip);
1092 
1093 	return 0;
1094 }
1095 
1096 /* Since a URB can handle only a single linear buffer, we must use double
1097  * buffering when the data to be transferred overflows the buffer boundary.
1098  * To avoid inconsistencies when updating hwptr_done, we use double buffering
1099  * for all URBs.
1100  */
1101 static void retire_capture_urb(struct snd_usb_substream *subs,
1102 			       struct urb *urb)
1103 {
1104 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1105 	unsigned int stride, frames, bytes, oldptr;
1106 	int i, period_elapsed = 0;
1107 	unsigned long flags;
1108 	unsigned char *cp;
1109 	int current_frame_number;
1110 
1111 	/* read frame number here, update pointer in critical section */
1112 	current_frame_number = usb_get_current_frame_number(subs->dev);
1113 
1114 	stride = runtime->frame_bits >> 3;
1115 
1116 	for (i = 0; i < urb->number_of_packets; i++) {
1117 		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset + subs->pkt_offset_adj;
1118 		if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
1119 			dev_dbg(&subs->dev->dev, "frame %d active: %d\n",
1120 				i, urb->iso_frame_desc[i].status);
1121 			// continue;
1122 		}
1123 		bytes = urb->iso_frame_desc[i].actual_length;
1124 		if (subs->stream_offset_adj > 0) {
1125 			unsigned int adj = min(subs->stream_offset_adj, bytes);
1126 			cp += adj;
1127 			bytes -= adj;
1128 			subs->stream_offset_adj -= adj;
1129 		}
1130 		frames = bytes / stride;
1131 		if (!subs->txfr_quirk)
1132 			bytes = frames * stride;
1133 		if (bytes % (runtime->sample_bits >> 3) != 0) {
1134 			int oldbytes = bytes;
1135 			bytes = frames * stride;
1136 			dev_warn_ratelimited(&subs->dev->dev,
1137 				 "Corrected urb data len. %d->%d\n",
1138 							oldbytes, bytes);
1139 		}
1140 		/* update the current pointer */
1141 		spin_lock_irqsave(&subs->lock, flags);
1142 		oldptr = subs->hwptr_done;
1143 		subs->hwptr_done += bytes;
1144 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1145 			subs->hwptr_done -= runtime->buffer_size * stride;
1146 		frames = (bytes + (oldptr % stride)) / stride;
1147 		subs->transfer_done += frames;
1148 		if (subs->transfer_done >= runtime->period_size) {
1149 			subs->transfer_done -= runtime->period_size;
1150 			period_elapsed = 1;
1151 		}
1152 		/* capture delay is by construction limited to one URB,
1153 		 * reset delays here
1154 		 */
1155 		runtime->delay = subs->last_delay = 0;
1156 
1157 		/* realign last_frame_number */
1158 		subs->last_frame_number = current_frame_number;
1159 		subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1160 
1161 		spin_unlock_irqrestore(&subs->lock, flags);
1162 		/* copy a data chunk */
1163 		if (oldptr + bytes > runtime->buffer_size * stride) {
1164 			unsigned int bytes1 =
1165 					runtime->buffer_size * stride - oldptr;
1166 			memcpy(runtime->dma_area + oldptr, cp, bytes1);
1167 			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
1168 		} else {
1169 			memcpy(runtime->dma_area + oldptr, cp, bytes);
1170 		}
1171 	}
1172 
1173 	if (period_elapsed)
1174 		snd_pcm_period_elapsed(subs->pcm_substream);
1175 }
1176 
1177 static inline void fill_playback_urb_dsd_dop(struct snd_usb_substream *subs,
1178 					     struct urb *urb, unsigned int bytes)
1179 {
1180 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1181 	unsigned int stride = runtime->frame_bits >> 3;
1182 	unsigned int dst_idx = 0;
1183 	unsigned int src_idx = subs->hwptr_done;
1184 	unsigned int wrap = runtime->buffer_size * stride;
1185 	u8 *dst = urb->transfer_buffer;
1186 	u8 *src = runtime->dma_area;
1187 	u8 marker[] = { 0x05, 0xfa };
1188 
1189 	/*
1190 	 * The DSP DOP format defines a way to transport DSD samples over
1191 	 * normal PCM data endpoints. It requires stuffing of marker bytes
1192 	 * (0x05 and 0xfa, alternating per sample frame), and then expects
1193 	 * 2 additional bytes of actual payload. The whole frame is stored
1194 	 * LSB.
1195 	 *
1196 	 * Hence, for a stereo transport, the buffer layout looks like this,
1197 	 * where L refers to left channel samples and R to right.
1198 	 *
1199 	 *   L1 L2 0x05   R1 R2 0x05   L3 L4 0xfa  R3 R4 0xfa
1200 	 *   L5 L6 0x05   R5 R6 0x05   L7 L8 0xfa  R7 R8 0xfa
1201 	 *   .....
1202 	 *
1203 	 */
1204 
1205 	while (bytes--) {
1206 		if (++subs->dsd_dop.byte_idx == 3) {
1207 			/* frame boundary? */
1208 			dst[dst_idx++] = marker[subs->dsd_dop.marker];
1209 			src_idx += 2;
1210 			subs->dsd_dop.byte_idx = 0;
1211 
1212 			if (++subs->dsd_dop.channel % runtime->channels == 0) {
1213 				/* alternate the marker */
1214 				subs->dsd_dop.marker++;
1215 				subs->dsd_dop.marker %= ARRAY_SIZE(marker);
1216 				subs->dsd_dop.channel = 0;
1217 			}
1218 		} else {
1219 			/* stuff the DSD payload */
1220 			int idx = (src_idx + subs->dsd_dop.byte_idx - 1) % wrap;
1221 
1222 			if (subs->cur_audiofmt->dsd_bitrev)
1223 				dst[dst_idx++] = bitrev8(src[idx]);
1224 			else
1225 				dst[dst_idx++] = src[idx];
1226 
1227 			subs->hwptr_done++;
1228 		}
1229 	}
1230 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1231 		subs->hwptr_done -= runtime->buffer_size * stride;
1232 }
1233 
1234 static void copy_to_urb(struct snd_usb_substream *subs, struct urb *urb,
1235 			int offset, int stride, unsigned int bytes)
1236 {
1237 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1238 
1239 	if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
1240 		/* err, the transferred area goes over buffer boundary. */
1241 		unsigned int bytes1 =
1242 			runtime->buffer_size * stride - subs->hwptr_done;
1243 		memcpy(urb->transfer_buffer + offset,
1244 		       runtime->dma_area + subs->hwptr_done, bytes1);
1245 		memcpy(urb->transfer_buffer + offset + bytes1,
1246 		       runtime->dma_area, bytes - bytes1);
1247 	} else {
1248 		memcpy(urb->transfer_buffer + offset,
1249 		       runtime->dma_area + subs->hwptr_done, bytes);
1250 	}
1251 	subs->hwptr_done += bytes;
1252 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1253 		subs->hwptr_done -= runtime->buffer_size * stride;
1254 }
1255 
1256 static unsigned int copy_to_urb_quirk(struct snd_usb_substream *subs,
1257 				      struct urb *urb, int stride,
1258 				      unsigned int bytes)
1259 {
1260 	__le32 packet_length;
1261 	int i;
1262 
1263 	/* Put __le32 length descriptor at start of each packet. */
1264 	for (i = 0; i < urb->number_of_packets; i++) {
1265 		unsigned int length = urb->iso_frame_desc[i].length;
1266 		unsigned int offset = urb->iso_frame_desc[i].offset;
1267 
1268 		packet_length = cpu_to_le32(length);
1269 		offset += i * sizeof(packet_length);
1270 		urb->iso_frame_desc[i].offset = offset;
1271 		urb->iso_frame_desc[i].length += sizeof(packet_length);
1272 		memcpy(urb->transfer_buffer + offset,
1273 		       &packet_length, sizeof(packet_length));
1274 		copy_to_urb(subs, urb, offset + sizeof(packet_length),
1275 			    stride, length);
1276 	}
1277 	/* Adjust transfer size accordingly. */
1278 	bytes += urb->number_of_packets * sizeof(packet_length);
1279 	return bytes;
1280 }
1281 
1282 static void prepare_playback_urb(struct snd_usb_substream *subs,
1283 				 struct urb *urb)
1284 {
1285 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1286 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1287 	struct snd_urb_ctx *ctx = urb->context;
1288 	unsigned int counts, frames, bytes;
1289 	int i, stride, period_elapsed = 0;
1290 	unsigned long flags;
1291 
1292 	stride = runtime->frame_bits >> 3;
1293 
1294 	frames = 0;
1295 	urb->number_of_packets = 0;
1296 	spin_lock_irqsave(&subs->lock, flags);
1297 	subs->frame_limit += ep->max_urb_frames;
1298 	for (i = 0; i < ctx->packets; i++) {
1299 		counts = snd_usb_endpoint_next_packet_size(ep, ctx, i);
1300 		/* set up descriptor */
1301 		urb->iso_frame_desc[i].offset = frames * ep->stride;
1302 		urb->iso_frame_desc[i].length = counts * ep->stride;
1303 		frames += counts;
1304 		urb->number_of_packets++;
1305 		subs->transfer_done += counts;
1306 		if (subs->transfer_done >= runtime->period_size) {
1307 			subs->transfer_done -= runtime->period_size;
1308 			subs->frame_limit = 0;
1309 			period_elapsed = 1;
1310 			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
1311 				if (subs->transfer_done > 0) {
1312 					/* FIXME: fill-max mode is not
1313 					 * supported yet */
1314 					frames -= subs->transfer_done;
1315 					counts -= subs->transfer_done;
1316 					urb->iso_frame_desc[i].length =
1317 						counts * ep->stride;
1318 					subs->transfer_done = 0;
1319 				}
1320 				i++;
1321 				if (i < ctx->packets) {
1322 					/* add a transfer delimiter */
1323 					urb->iso_frame_desc[i].offset =
1324 						frames * ep->stride;
1325 					urb->iso_frame_desc[i].length = 0;
1326 					urb->number_of_packets++;
1327 				}
1328 				break;
1329 			}
1330 		}
1331 		/* finish at the period boundary or after enough frames */
1332 		if ((period_elapsed ||
1333 				subs->transfer_done >= subs->frame_limit) &&
1334 		    !snd_usb_endpoint_implicit_feedback_sink(ep))
1335 			break;
1336 	}
1337 	bytes = frames * ep->stride;
1338 
1339 	if (unlikely(ep->cur_format == SNDRV_PCM_FORMAT_DSD_U16_LE &&
1340 		     subs->cur_audiofmt->dsd_dop)) {
1341 		fill_playback_urb_dsd_dop(subs, urb, bytes);
1342 	} else if (unlikely(ep->cur_format == SNDRV_PCM_FORMAT_DSD_U8 &&
1343 			   subs->cur_audiofmt->dsd_bitrev)) {
1344 		/* bit-reverse the bytes */
1345 		u8 *buf = urb->transfer_buffer;
1346 		for (i = 0; i < bytes; i++) {
1347 			int idx = (subs->hwptr_done + i)
1348 				% (runtime->buffer_size * stride);
1349 			buf[i] = bitrev8(runtime->dma_area[idx]);
1350 		}
1351 
1352 		subs->hwptr_done += bytes;
1353 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1354 			subs->hwptr_done -= runtime->buffer_size * stride;
1355 	} else {
1356 		/* usual PCM */
1357 		if (!subs->tx_length_quirk)
1358 			copy_to_urb(subs, urb, 0, stride, bytes);
1359 		else
1360 			bytes = copy_to_urb_quirk(subs, urb, stride, bytes);
1361 			/* bytes is now amount of outgoing data */
1362 	}
1363 
1364 	/* update delay with exact number of samples queued */
1365 	runtime->delay = subs->last_delay;
1366 	runtime->delay += frames;
1367 	subs->last_delay = runtime->delay;
1368 
1369 	/* realign last_frame_number */
1370 	subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1371 	subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1372 
1373 	if (subs->trigger_tstamp_pending_update) {
1374 		/* this is the first actual URB submitted,
1375 		 * update trigger timestamp to reflect actual start time
1376 		 */
1377 		snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
1378 		subs->trigger_tstamp_pending_update = false;
1379 	}
1380 
1381 	spin_unlock_irqrestore(&subs->lock, flags);
1382 	urb->transfer_buffer_length = bytes;
1383 	if (period_elapsed)
1384 		snd_pcm_period_elapsed(subs->pcm_substream);
1385 }
1386 
1387 /*
1388  * process after playback data complete
1389  * - decrease the delay count again
1390  */
1391 static void retire_playback_urb(struct snd_usb_substream *subs,
1392 			       struct urb *urb)
1393 {
1394 	unsigned long flags;
1395 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1396 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1397 	int processed = urb->transfer_buffer_length / ep->stride;
1398 	int est_delay;
1399 
1400 	/* ignore the delay accounting when processed=0 is given, i.e.
1401 	 * silent payloads are processed before handling the actual data
1402 	 */
1403 	if (!processed)
1404 		return;
1405 
1406 	spin_lock_irqsave(&subs->lock, flags);
1407 	if (!subs->last_delay)
1408 		goto out; /* short path */
1409 
1410 	est_delay = snd_usb_pcm_delay(subs, runtime->rate);
1411 	/* update delay with exact number of samples played */
1412 	if (processed > subs->last_delay)
1413 		subs->last_delay = 0;
1414 	else
1415 		subs->last_delay -= processed;
1416 	runtime->delay = subs->last_delay;
1417 
1418 	/*
1419 	 * Report when delay estimate is off by more than 2ms.
1420 	 * The error should be lower than 2ms since the estimate relies
1421 	 * on two reads of a counter updated every ms.
1422 	 */
1423 	if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
1424 		dev_dbg_ratelimited(&subs->dev->dev,
1425 			"delay: estimated %d, actual %d\n",
1426 			est_delay, subs->last_delay);
1427 
1428 	if (!subs->running) {
1429 		/* update last_frame_number for delay counting here since
1430 		 * prepare_playback_urb won't be called during pause
1431 		 */
1432 		subs->last_frame_number =
1433 			usb_get_current_frame_number(subs->dev) & 0xff;
1434 	}
1435 
1436  out:
1437 	spin_unlock_irqrestore(&subs->lock, flags);
1438 }
1439 
1440 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream,
1441 					      int cmd)
1442 {
1443 	struct snd_usb_substream *subs = substream->runtime->private_data;
1444 
1445 	switch (cmd) {
1446 	case SNDRV_PCM_TRIGGER_START:
1447 		subs->trigger_tstamp_pending_update = true;
1448 		fallthrough;
1449 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1450 		snd_usb_endpoint_set_callback(subs->data_endpoint,
1451 					      prepare_playback_urb,
1452 					      retire_playback_urb,
1453 					      subs);
1454 		subs->running = 1;
1455 		dev_dbg(&subs->dev->dev, "%d:%d Start Playback PCM\n",
1456 			subs->cur_audiofmt->iface,
1457 			subs->cur_audiofmt->altsetting);
1458 		return 0;
1459 	case SNDRV_PCM_TRIGGER_SUSPEND:
1460 	case SNDRV_PCM_TRIGGER_STOP:
1461 		stop_endpoints(subs);
1462 		snd_usb_endpoint_set_callback(subs->data_endpoint,
1463 					      NULL, NULL, NULL);
1464 		subs->running = 0;
1465 		dev_dbg(&subs->dev->dev, "%d:%d Stop Playback PCM\n",
1466 			subs->cur_audiofmt->iface,
1467 			subs->cur_audiofmt->altsetting);
1468 		return 0;
1469 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1470 		/* keep retire_data_urb for delay calculation */
1471 		snd_usb_endpoint_set_callback(subs->data_endpoint,
1472 					      NULL,
1473 					      retire_playback_urb,
1474 					      subs);
1475 		subs->running = 0;
1476 		dev_dbg(&subs->dev->dev, "%d:%d Pause Playback PCM\n",
1477 			subs->cur_audiofmt->iface,
1478 			subs->cur_audiofmt->altsetting);
1479 		return 0;
1480 	}
1481 
1482 	return -EINVAL;
1483 }
1484 
1485 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream,
1486 					     int cmd)
1487 {
1488 	int err;
1489 	struct snd_usb_substream *subs = substream->runtime->private_data;
1490 
1491 	switch (cmd) {
1492 	case SNDRV_PCM_TRIGGER_START:
1493 		err = start_endpoints(subs);
1494 		if (err < 0)
1495 			return err;
1496 		fallthrough;
1497 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1498 		snd_usb_endpoint_set_callback(subs->data_endpoint,
1499 					      NULL, retire_capture_urb,
1500 					      subs);
1501 		subs->running = 1;
1502 		dev_dbg(&subs->dev->dev, "%d:%d Start Capture PCM\n",
1503 			subs->cur_audiofmt->iface,
1504 			subs->cur_audiofmt->altsetting);
1505 		return 0;
1506 	case SNDRV_PCM_TRIGGER_SUSPEND:
1507 	case SNDRV_PCM_TRIGGER_STOP:
1508 		stop_endpoints(subs);
1509 		fallthrough;
1510 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1511 		snd_usb_endpoint_set_callback(subs->data_endpoint,
1512 					      NULL, NULL, NULL);
1513 		subs->running = 0;
1514 		dev_dbg(&subs->dev->dev, "%d:%d Stop Capture PCM\n",
1515 			subs->cur_audiofmt->iface,
1516 			subs->cur_audiofmt->altsetting);
1517 		return 0;
1518 	}
1519 
1520 	return -EINVAL;
1521 }
1522 
1523 static const struct snd_pcm_ops snd_usb_playback_ops = {
1524 	.open =		snd_usb_pcm_open,
1525 	.close =	snd_usb_pcm_close,
1526 	.hw_params =	snd_usb_hw_params,
1527 	.hw_free =	snd_usb_hw_free,
1528 	.prepare =	snd_usb_pcm_prepare,
1529 	.trigger =	snd_usb_substream_playback_trigger,
1530 	.sync_stop =	snd_usb_pcm_sync_stop,
1531 	.pointer =	snd_usb_pcm_pointer,
1532 };
1533 
1534 static const struct snd_pcm_ops snd_usb_capture_ops = {
1535 	.open =		snd_usb_pcm_open,
1536 	.close =	snd_usb_pcm_close,
1537 	.hw_params =	snd_usb_hw_params,
1538 	.hw_free =	snd_usb_hw_free,
1539 	.prepare =	snd_usb_pcm_prepare,
1540 	.trigger =	snd_usb_substream_capture_trigger,
1541 	.sync_stop =	snd_usb_pcm_sync_stop,
1542 	.pointer =	snd_usb_pcm_pointer,
1543 };
1544 
1545 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
1546 {
1547 	const struct snd_pcm_ops *ops;
1548 
1549 	ops = stream == SNDRV_PCM_STREAM_PLAYBACK ?
1550 			&snd_usb_playback_ops : &snd_usb_capture_ops;
1551 	snd_pcm_set_ops(pcm, stream, ops);
1552 }
1553 
1554 void snd_usb_preallocate_buffer(struct snd_usb_substream *subs)
1555 {
1556 	struct snd_pcm *pcm = subs->stream->pcm;
1557 	struct snd_pcm_substream *s = pcm->streams[subs->direction].substream;
1558 	struct device *dev = subs->dev->bus->sysdev;
1559 
1560 	if (snd_usb_use_vmalloc)
1561 		snd_pcm_set_managed_buffer(s, SNDRV_DMA_TYPE_VMALLOC,
1562 					   NULL, 0, 0);
1563 	else
1564 		snd_pcm_set_managed_buffer(s, SNDRV_DMA_TYPE_DEV_SG,
1565 					   dev, 64*1024, 512*1024);
1566 }
1567