1 // SPDX-License-Identifier: GPL-2.0-or-later
5 #include <linux/init.h>
6 #include <linux/slab.h>
7 #include <linux/bitrev.h>
8 #include <linux/ratelimit.h>
10 #include <linux/usb/audio.h>
11 #include <linux/usb/audio-v2.h>
13 #include <sound/core.h>
14 #include <sound/pcm.h>
15 #include <sound/pcm_params.h>
28 #define SUBSTREAM_FLAG_DATA_EP_STARTED 0
29 #define SUBSTREAM_FLAG_SYNC_EP_STARTED 1
31 /* return the estimated delay based on USB frame counters */
32 static snd_pcm_uframes_t snd_usb_pcm_delay(struct snd_usb_substream *subs,
33 struct snd_pcm_runtime *runtime)
35 unsigned int current_frame_number;
36 unsigned int frame_diff;
40 if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
41 queued = bytes_to_frames(runtime, subs->inflight_bytes);
44 } else if (!subs->running) {
48 current_frame_number = usb_get_current_frame_number(subs->dev);
50 * HCD implementations use different widths, use lower 8 bits.
51 * The delay will be managed up to 256ms, which is more than
54 frame_diff = (current_frame_number - subs->last_frame_number) & 0xff;
56 /* Approximation based on number of samples per USB frame (ms),
57 some truncation for 44.1 but the estimate is good enough */
58 est_delay = frame_diff * runtime->rate / 1000;
60 if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
61 est_delay = queued - est_delay;
70 * return the current pcm pointer. just based on the hwptr_done value.
72 static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream)
74 struct snd_pcm_runtime *runtime = substream->runtime;
75 struct snd_usb_substream *subs = runtime->private_data;
76 unsigned int hwptr_done;
78 if (atomic_read(&subs->stream->chip->shutdown))
79 return SNDRV_PCM_POS_XRUN;
80 spin_lock(&subs->lock);
81 hwptr_done = subs->hwptr_done;
82 runtime->delay = snd_usb_pcm_delay(subs, runtime);
83 spin_unlock(&subs->lock);
84 return bytes_to_frames(runtime, hwptr_done);
88 * find a matching audio format
90 static const struct audioformat *
91 find_format(struct list_head *fmt_list_head, snd_pcm_format_t format,
92 unsigned int rate, unsigned int channels, bool strict_match,
93 struct snd_usb_substream *subs)
95 const struct audioformat *fp;
96 const struct audioformat *found = NULL;
97 int cur_attr = 0, attr;
99 list_for_each_entry(fp, fmt_list_head, list) {
101 if (!(fp->formats & pcm_format_to_bits(format)))
103 if (fp->channels != channels)
106 if (rate < fp->rate_min || rate > fp->rate_max)
108 if (!(fp->rates & SNDRV_PCM_RATE_CONTINUOUS)) {
110 for (i = 0; i < fp->nr_rates; i++)
111 if (fp->rate_table[i] == rate)
113 if (i >= fp->nr_rates)
116 attr = fp->ep_attr & USB_ENDPOINT_SYNCTYPE;
122 /* avoid async out and adaptive in if the other method
123 * supports the same format.
124 * this is a workaround for the case like
125 * M-audio audiophile USB.
127 if (subs && attr != cur_attr) {
128 if ((attr == USB_ENDPOINT_SYNC_ASYNC &&
129 subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
130 (attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
131 subs->direction == SNDRV_PCM_STREAM_CAPTURE))
133 if ((cur_attr == USB_ENDPOINT_SYNC_ASYNC &&
134 subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
135 (cur_attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
136 subs->direction == SNDRV_PCM_STREAM_CAPTURE)) {
142 /* find the format with the largest max. packet size */
143 if (fp->maxpacksize > found->maxpacksize) {
151 static const struct audioformat *
152 find_substream_format(struct snd_usb_substream *subs,
153 const struct snd_pcm_hw_params *params)
155 return find_format(&subs->fmt_list, params_format(params),
156 params_rate(params), params_channels(params),
160 static int init_pitch_v1(struct snd_usb_audio *chip, int ep)
162 struct usb_device *dev = chip->dev;
163 unsigned char data[1];
167 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
168 USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
169 UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep,
174 static int init_pitch_v2(struct snd_usb_audio *chip, int ep)
176 struct usb_device *dev = chip->dev;
177 unsigned char data[1];
181 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
182 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
183 UAC2_EP_CS_PITCH << 8, 0,
189 * initialize the pitch control and sample rate
191 int snd_usb_init_pitch(struct snd_usb_audio *chip,
192 const struct audioformat *fmt)
196 /* if endpoint doesn't have pitch control, bail out */
197 if (!(fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL))
200 usb_audio_dbg(chip, "enable PITCH for EP 0x%x\n", fmt->endpoint);
202 switch (fmt->protocol) {
204 err = init_pitch_v1(chip, fmt->endpoint);
207 err = init_pitch_v2(chip, fmt->endpoint);
214 usb_audio_err(chip, "failed to enable PITCH for EP 0x%x\n",
222 static bool stop_endpoints(struct snd_usb_substream *subs)
226 if (test_and_clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) {
227 snd_usb_endpoint_stop(subs->sync_endpoint);
230 if (test_and_clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags)) {
231 snd_usb_endpoint_stop(subs->data_endpoint);
237 static int start_endpoints(struct snd_usb_substream *subs)
241 if (!subs->data_endpoint)
244 if (!test_and_set_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags)) {
245 err = snd_usb_endpoint_start(subs->data_endpoint);
247 clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags);
252 if (subs->sync_endpoint &&
253 !test_and_set_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) {
254 err = snd_usb_endpoint_start(subs->sync_endpoint);
256 clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
264 stop_endpoints(subs);
268 static void sync_pending_stops(struct snd_usb_substream *subs)
270 snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
271 snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
274 /* PCM sync_stop callback */
275 static int snd_usb_pcm_sync_stop(struct snd_pcm_substream *substream)
277 struct snd_usb_substream *subs = substream->runtime->private_data;
279 sync_pending_stops(subs);
283 /* Set up sync endpoint */
284 int snd_usb_audioformat_set_sync_ep(struct snd_usb_audio *chip,
285 struct audioformat *fmt)
287 struct usb_device *dev = chip->dev;
288 struct usb_host_interface *alts;
289 struct usb_interface_descriptor *altsd;
290 unsigned int ep, attr, sync_attr;
294 alts = snd_usb_get_host_interface(chip, fmt->iface, fmt->altsetting);
297 altsd = get_iface_desc(alts);
299 err = snd_usb_parse_implicit_fb_quirk(chip, fmt, alts);
301 return 0; /* matched */
304 * Generic sync EP handling
307 if (altsd->bNumEndpoints < 2)
310 is_playback = !(get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN);
311 attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
312 if ((is_playback && (attr == USB_ENDPOINT_SYNC_SYNC ||
313 attr == USB_ENDPOINT_SYNC_ADAPTIVE)) ||
314 (!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE))
317 sync_attr = get_endpoint(alts, 1)->bmAttributes;
320 * In case of illegal SYNC_NONE for OUT endpoint, we keep going to see
321 * if we don't find a sync endpoint, as on M-Audio Transit. In case of
322 * error fall back to SYNC mode and don't create sync endpoint
325 /* check sync-pipe endpoint */
326 /* ... and check descriptor size before accessing bSynchAddress
327 because there is a version of the SB Audigy 2 NX firmware lacking
328 the audio fields in the endpoint descriptors */
329 if ((sync_attr & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC ||
330 (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
331 get_endpoint(alts, 1)->bSynchAddress != 0)) {
333 "%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
334 fmt->iface, fmt->altsetting,
335 get_endpoint(alts, 1)->bmAttributes,
336 get_endpoint(alts, 1)->bLength,
337 get_endpoint(alts, 1)->bSynchAddress);
338 if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
342 ep = get_endpoint(alts, 1)->bEndpointAddress;
343 if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
344 get_endpoint(alts, 0)->bSynchAddress != 0 &&
345 ((is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
346 (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
348 "%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
349 fmt->iface, fmt->altsetting,
350 is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
351 if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
357 fmt->sync_iface = altsd->bInterfaceNumber;
358 fmt->sync_altsetting = altsd->bAlternateSetting;
359 fmt->sync_ep_idx = 1;
360 if ((sync_attr & USB_ENDPOINT_USAGE_MASK) == USB_ENDPOINT_USAGE_IMPLICIT_FB)
361 fmt->implicit_fb = 1;
363 dev_dbg(&dev->dev, "%d:%d: found sync_ep=0x%x, iface=%d, alt=%d, implicit_fb=%d\n",
364 fmt->iface, fmt->altsetting, fmt->sync_ep, fmt->sync_iface,
365 fmt->sync_altsetting, fmt->implicit_fb);
370 static int snd_usb_pcm_change_state(struct snd_usb_substream *subs, int state)
377 ret = snd_usb_power_domain_set(subs->stream->chip, subs->str_pd, state);
379 dev_err(&subs->dev->dev,
380 "Cannot change Power Domain ID: %d to state: %d. Err: %d\n",
381 subs->str_pd->pd_id, state, ret);
388 int snd_usb_pcm_suspend(struct snd_usb_stream *as)
392 ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D2);
396 ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D2);
403 int snd_usb_pcm_resume(struct snd_usb_stream *as)
407 ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D1);
411 ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D1);
418 static void close_endpoints(struct snd_usb_audio *chip,
419 struct snd_usb_substream *subs)
421 if (subs->data_endpoint) {
422 snd_usb_endpoint_set_sync(chip, subs->data_endpoint, NULL);
423 snd_usb_endpoint_close(chip, subs->data_endpoint);
424 subs->data_endpoint = NULL;
427 if (subs->sync_endpoint) {
428 snd_usb_endpoint_close(chip, subs->sync_endpoint);
429 subs->sync_endpoint = NULL;
433 static int configure_endpoints(struct snd_usb_audio *chip,
434 struct snd_usb_substream *subs)
438 if (subs->data_endpoint->need_setup) {
439 /* stop any running stream beforehand */
440 if (stop_endpoints(subs))
441 sync_pending_stops(subs);
442 err = snd_usb_endpoint_configure(chip, subs->data_endpoint);
445 snd_usb_set_format_quirk(subs, subs->cur_audiofmt);
448 if (subs->sync_endpoint) {
449 err = snd_usb_endpoint_configure(chip, subs->sync_endpoint);
460 * allocate a buffer and set the given audio format.
462 * so far we use a physically linear buffer although packetize transfer
463 * doesn't need a continuous area.
464 * if sg buffer is supported on the later version of alsa, we'll follow
467 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
468 struct snd_pcm_hw_params *hw_params)
470 struct snd_usb_substream *subs = substream->runtime->private_data;
471 struct snd_usb_audio *chip = subs->stream->chip;
472 const struct audioformat *fmt;
473 const struct audioformat *sync_fmt;
476 ret = snd_media_start_pipeline(subs);
480 fmt = find_substream_format(subs, hw_params);
483 "cannot find format: format=%s, rate=%d, channels=%d\n",
484 snd_pcm_format_name(params_format(hw_params)),
485 params_rate(hw_params), params_channels(hw_params));
490 if (fmt->implicit_fb) {
491 sync_fmt = snd_usb_find_implicit_fb_sync_format(chip, fmt,
496 "cannot find sync format: ep=0x%x, iface=%d:%d, format=%s, rate=%d, channels=%d\n",
497 fmt->sync_ep, fmt->sync_iface,
498 fmt->sync_altsetting,
499 snd_pcm_format_name(params_format(hw_params)),
500 params_rate(hw_params), params_channels(hw_params));
508 ret = snd_usb_lock_shutdown(chip);
512 ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
516 if (subs->data_endpoint) {
517 if (snd_usb_endpoint_compatible(chip, subs->data_endpoint,
520 close_endpoints(chip, subs);
523 subs->data_endpoint = snd_usb_endpoint_open(chip, fmt, hw_params, false);
524 if (!subs->data_endpoint) {
530 subs->sync_endpoint = snd_usb_endpoint_open(chip, sync_fmt,
533 if (!subs->sync_endpoint) {
538 snd_usb_endpoint_set_sync(chip, subs->data_endpoint,
539 subs->sync_endpoint);
542 mutex_lock(&chip->mutex);
543 subs->cur_audiofmt = fmt;
544 mutex_unlock(&chip->mutex);
546 ret = configure_endpoints(chip, subs);
550 close_endpoints(chip, subs);
552 snd_usb_unlock_shutdown(chip);
555 snd_media_stop_pipeline(subs);
563 * reset the audio format and release the buffer
565 static int snd_usb_hw_free(struct snd_pcm_substream *substream)
567 struct snd_usb_substream *subs = substream->runtime->private_data;
568 struct snd_usb_audio *chip = subs->stream->chip;
570 snd_media_stop_pipeline(subs);
571 mutex_lock(&chip->mutex);
572 subs->cur_audiofmt = NULL;
573 mutex_unlock(&chip->mutex);
574 if (!snd_usb_lock_shutdown(chip)) {
575 if (stop_endpoints(subs))
576 sync_pending_stops(subs);
577 close_endpoints(chip, subs);
578 snd_usb_unlock_shutdown(chip);
587 * only a few subtle things...
589 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
591 struct snd_pcm_runtime *runtime = substream->runtime;
592 struct snd_usb_substream *subs = runtime->private_data;
593 struct snd_usb_audio *chip = subs->stream->chip;
596 ret = snd_usb_lock_shutdown(chip);
599 if (snd_BUG_ON(!subs->data_endpoint)) {
604 ret = configure_endpoints(chip, subs);
608 /* reset the pointer */
609 subs->buffer_bytes = frames_to_bytes(runtime, runtime->buffer_size);
610 subs->inflight_bytes = 0;
611 subs->hwptr_done = 0;
612 subs->transfer_done = 0;
613 subs->last_frame_number = 0;
617 snd_usb_unlock_shutdown(chip);
625 #ifdef HW_CONST_DEBUG
626 #define hwc_debug(fmt, args...) pr_debug(fmt, ##args)
628 #define hwc_debug(fmt, args...) do { } while(0)
631 static const struct snd_pcm_hardware snd_usb_hardware =
633 .info = SNDRV_PCM_INFO_MMAP |
634 SNDRV_PCM_INFO_MMAP_VALID |
635 SNDRV_PCM_INFO_BATCH |
636 SNDRV_PCM_INFO_INTERLEAVED |
637 SNDRV_PCM_INFO_BLOCK_TRANSFER |
638 SNDRV_PCM_INFO_PAUSE,
641 .buffer_bytes_max = 1024 * 1024,
642 .period_bytes_min = 64,
643 .period_bytes_max = 512 * 1024,
648 static int hw_check_valid_format(struct snd_usb_substream *subs,
649 struct snd_pcm_hw_params *params,
650 const struct audioformat *fp)
652 struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
653 struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
654 struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
655 struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
656 struct snd_mask check_fmts;
659 /* check the format */
660 snd_mask_none(&check_fmts);
661 check_fmts.bits[0] = (u32)fp->formats;
662 check_fmts.bits[1] = (u32)(fp->formats >> 32);
663 snd_mask_intersect(&check_fmts, fmts);
664 if (snd_mask_empty(&check_fmts)) {
665 hwc_debug(" > check: no supported format 0x%llx\n", fp->formats);
668 /* check the channels */
669 if (fp->channels < ct->min || fp->channels > ct->max) {
670 hwc_debug(" > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
673 /* check the rate is within the range */
674 if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
675 hwc_debug(" > check: rate_min %d > max %d\n", fp->rate_min, it->max);
678 if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
679 hwc_debug(" > check: rate_max %d < min %d\n", fp->rate_max, it->min);
682 /* check whether the period time is >= the data packet interval */
683 if (subs->speed != USB_SPEED_FULL) {
684 ptime = 125 * (1 << fp->datainterval);
685 if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
686 hwc_debug(" > check: ptime %u > max %u\n", ptime, pt->max);
693 static int apply_hw_params_minmax(struct snd_interval *it, unsigned int rmin,
699 hwc_debug(" --> get empty\n");
705 if (it->min < rmin) {
710 if (it->max > rmax) {
715 if (snd_interval_checkempty(it)) {
719 hwc_debug(" --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
723 static int hw_rule_rate(struct snd_pcm_hw_params *params,
724 struct snd_pcm_hw_rule *rule)
726 struct snd_usb_substream *subs = rule->private;
727 const struct audioformat *fp;
728 struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
729 unsigned int rmin, rmax, r;
732 hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
735 list_for_each_entry(fp, &subs->fmt_list, list) {
736 if (!hw_check_valid_format(subs, params, fp))
738 if (fp->rate_table && fp->nr_rates) {
739 for (i = 0; i < fp->nr_rates; i++) {
740 r = fp->rate_table[i];
741 if (!snd_interval_test(it, r))
747 rmin = min(rmin, fp->rate_min);
748 rmax = max(rmax, fp->rate_max);
752 return apply_hw_params_minmax(it, rmin, rmax);
756 static int hw_rule_channels(struct snd_pcm_hw_params *params,
757 struct snd_pcm_hw_rule *rule)
759 struct snd_usb_substream *subs = rule->private;
760 const struct audioformat *fp;
761 struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
762 unsigned int rmin, rmax;
764 hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
767 list_for_each_entry(fp, &subs->fmt_list, list) {
768 if (!hw_check_valid_format(subs, params, fp))
770 rmin = min(rmin, fp->channels);
771 rmax = max(rmax, fp->channels);
774 return apply_hw_params_minmax(it, rmin, rmax);
777 static int apply_hw_params_format_bits(struct snd_mask *fmt, u64 fbits)
782 oldbits[0] = fmt->bits[0];
783 oldbits[1] = fmt->bits[1];
784 fmt->bits[0] &= (u32)fbits;
785 fmt->bits[1] &= (u32)(fbits >> 32);
786 if (!fmt->bits[0] && !fmt->bits[1]) {
787 hwc_debug(" --> get empty\n");
790 changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
791 hwc_debug(" --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
795 static int hw_rule_format(struct snd_pcm_hw_params *params,
796 struct snd_pcm_hw_rule *rule)
798 struct snd_usb_substream *subs = rule->private;
799 const struct audioformat *fp;
800 struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
803 hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
805 list_for_each_entry(fp, &subs->fmt_list, list) {
806 if (!hw_check_valid_format(subs, params, fp))
808 fbits |= fp->formats;
810 return apply_hw_params_format_bits(fmt, fbits);
813 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
814 struct snd_pcm_hw_rule *rule)
816 struct snd_usb_substream *subs = rule->private;
817 const struct audioformat *fp;
818 struct snd_interval *it;
819 unsigned char min_datainterval;
822 it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
823 hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
824 min_datainterval = 0xff;
825 list_for_each_entry(fp, &subs->fmt_list, list) {
826 if (!hw_check_valid_format(subs, params, fp))
828 min_datainterval = min(min_datainterval, fp->datainterval);
830 if (min_datainterval == 0xff) {
831 hwc_debug(" --> get empty\n");
835 pmin = 125 * (1 << min_datainterval);
837 return apply_hw_params_minmax(it, pmin, UINT_MAX);
840 /* get the EP or the sync EP for implicit fb when it's already set up */
841 static const struct snd_usb_endpoint *
842 get_sync_ep_from_substream(struct snd_usb_substream *subs)
844 struct snd_usb_audio *chip = subs->stream->chip;
845 const struct audioformat *fp;
846 const struct snd_usb_endpoint *ep;
848 list_for_each_entry(fp, &subs->fmt_list, list) {
849 ep = snd_usb_get_endpoint(chip, fp->endpoint);
850 if (ep && ep->cur_audiofmt) {
851 /* if EP is already opened solely for this substream,
852 * we still allow us to change the parameter; otherwise
853 * this substream has to follow the existing parameter
855 if (ep->cur_audiofmt != subs->cur_audiofmt || ep->opened > 1)
858 if (!fp->implicit_fb)
860 /* for the implicit fb, check the sync ep as well */
861 ep = snd_usb_get_endpoint(chip, fp->sync_ep);
862 if (ep && ep->cur_audiofmt)
868 /* additional hw constraints for implicit feedback mode */
869 static int hw_rule_format_implicit_fb(struct snd_pcm_hw_params *params,
870 struct snd_pcm_hw_rule *rule)
872 struct snd_usb_substream *subs = rule->private;
873 const struct snd_usb_endpoint *ep;
874 struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
876 ep = get_sync_ep_from_substream(subs);
880 hwc_debug("applying %s\n", __func__);
881 return apply_hw_params_format_bits(fmt, pcm_format_to_bits(ep->cur_format));
884 static int hw_rule_rate_implicit_fb(struct snd_pcm_hw_params *params,
885 struct snd_pcm_hw_rule *rule)
887 struct snd_usb_substream *subs = rule->private;
888 const struct snd_usb_endpoint *ep;
889 struct snd_interval *it;
891 ep = get_sync_ep_from_substream(subs);
895 hwc_debug("applying %s\n", __func__);
896 it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
897 return apply_hw_params_minmax(it, ep->cur_rate, ep->cur_rate);
900 static int hw_rule_period_size_implicit_fb(struct snd_pcm_hw_params *params,
901 struct snd_pcm_hw_rule *rule)
903 struct snd_usb_substream *subs = rule->private;
904 const struct snd_usb_endpoint *ep;
905 struct snd_interval *it;
907 ep = get_sync_ep_from_substream(subs);
911 hwc_debug("applying %s\n", __func__);
912 it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE);
913 return apply_hw_params_minmax(it, ep->cur_period_frames,
914 ep->cur_period_frames);
917 static int hw_rule_periods_implicit_fb(struct snd_pcm_hw_params *params,
918 struct snd_pcm_hw_rule *rule)
920 struct snd_usb_substream *subs = rule->private;
921 const struct snd_usb_endpoint *ep;
922 struct snd_interval *it;
924 ep = get_sync_ep_from_substream(subs);
928 hwc_debug("applying %s\n", __func__);
929 it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIODS);
930 return apply_hw_params_minmax(it, ep->cur_buffer_periods,
931 ep->cur_buffer_periods);
935 * set up the runtime hardware information.
938 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
940 const struct audioformat *fp;
941 unsigned int pt, ptmin;
942 int param_period_time_if_needed = -1;
945 runtime->hw.formats = subs->formats;
947 runtime->hw.rate_min = 0x7fffffff;
948 runtime->hw.rate_max = 0;
949 runtime->hw.channels_min = 256;
950 runtime->hw.channels_max = 0;
951 runtime->hw.rates = 0;
953 /* check min/max rates and channels */
954 list_for_each_entry(fp, &subs->fmt_list, list) {
955 runtime->hw.rates |= fp->rates;
956 if (runtime->hw.rate_min > fp->rate_min)
957 runtime->hw.rate_min = fp->rate_min;
958 if (runtime->hw.rate_max < fp->rate_max)
959 runtime->hw.rate_max = fp->rate_max;
960 if (runtime->hw.channels_min > fp->channels)
961 runtime->hw.channels_min = fp->channels;
962 if (runtime->hw.channels_max < fp->channels)
963 runtime->hw.channels_max = fp->channels;
964 if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
965 /* FIXME: there might be more than one audio formats... */
966 runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
969 pt = 125 * (1 << fp->datainterval);
970 ptmin = min(ptmin, pt);
973 param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
974 if (subs->speed == USB_SPEED_FULL)
975 /* full speed devices have fixed data packet interval */
978 /* if period time doesn't go below 1 ms, no rules needed */
979 param_period_time_if_needed = -1;
981 err = snd_pcm_hw_constraint_minmax(runtime,
982 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
987 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
989 SNDRV_PCM_HW_PARAM_RATE,
990 SNDRV_PCM_HW_PARAM_FORMAT,
991 SNDRV_PCM_HW_PARAM_CHANNELS,
992 param_period_time_if_needed,
997 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
998 hw_rule_channels, subs,
999 SNDRV_PCM_HW_PARAM_CHANNELS,
1000 SNDRV_PCM_HW_PARAM_FORMAT,
1001 SNDRV_PCM_HW_PARAM_RATE,
1002 param_period_time_if_needed,
1006 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
1007 hw_rule_format, subs,
1008 SNDRV_PCM_HW_PARAM_FORMAT,
1009 SNDRV_PCM_HW_PARAM_RATE,
1010 SNDRV_PCM_HW_PARAM_CHANNELS,
1011 param_period_time_if_needed,
1015 if (param_period_time_if_needed >= 0) {
1016 err = snd_pcm_hw_rule_add(runtime, 0,
1017 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1018 hw_rule_period_time, subs,
1019 SNDRV_PCM_HW_PARAM_FORMAT,
1020 SNDRV_PCM_HW_PARAM_CHANNELS,
1021 SNDRV_PCM_HW_PARAM_RATE,
1027 /* additional hw constraints for implicit fb */
1028 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
1029 hw_rule_format_implicit_fb, subs,
1030 SNDRV_PCM_HW_PARAM_FORMAT, -1);
1033 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1034 hw_rule_rate_implicit_fb, subs,
1035 SNDRV_PCM_HW_PARAM_RATE, -1);
1038 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
1039 hw_rule_period_size_implicit_fb, subs,
1040 SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
1043 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIODS,
1044 hw_rule_periods_implicit_fb, subs,
1045 SNDRV_PCM_HW_PARAM_PERIODS, -1);
1052 static int snd_usb_pcm_open(struct snd_pcm_substream *substream)
1054 int direction = substream->stream;
1055 struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1056 struct snd_pcm_runtime *runtime = substream->runtime;
1057 struct snd_usb_substream *subs = &as->substream[direction];
1060 runtime->hw = snd_usb_hardware;
1061 runtime->private_data = subs;
1062 subs->pcm_substream = substream;
1063 /* runtime PM is also done there */
1065 /* initialize DSD/DOP context */
1066 subs->dsd_dop.byte_idx = 0;
1067 subs->dsd_dop.channel = 0;
1068 subs->dsd_dop.marker = 1;
1070 ret = setup_hw_info(runtime, subs);
1073 ret = snd_usb_autoresume(subs->stream->chip);
1076 ret = snd_media_stream_init(subs, as->pcm, direction);
1078 snd_usb_autosuspend(subs->stream->chip);
1082 static int snd_usb_pcm_close(struct snd_pcm_substream *substream)
1084 int direction = substream->stream;
1085 struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1086 struct snd_usb_substream *subs = &as->substream[direction];
1089 snd_media_stop_pipeline(subs);
1091 if (!snd_usb_lock_shutdown(subs->stream->chip)) {
1092 ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D1);
1093 snd_usb_unlock_shutdown(subs->stream->chip);
1098 subs->pcm_substream = NULL;
1099 snd_usb_autosuspend(subs->stream->chip);
1104 /* Since a URB can handle only a single linear buffer, we must use double
1105 * buffering when the data to be transferred overflows the buffer boundary.
1106 * To avoid inconsistencies when updating hwptr_done, we use double buffering
1109 static void retire_capture_urb(struct snd_usb_substream *subs,
1112 struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1113 unsigned int stride, frames, bytes, oldptr;
1114 int i, period_elapsed = 0;
1115 unsigned long flags;
1117 int current_frame_number;
1119 /* read frame number here, update pointer in critical section */
1120 current_frame_number = usb_get_current_frame_number(subs->dev);
1122 stride = runtime->frame_bits >> 3;
1124 for (i = 0; i < urb->number_of_packets; i++) {
1125 cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset + subs->pkt_offset_adj;
1126 if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
1127 dev_dbg(&subs->dev->dev, "frame %d active: %d\n",
1128 i, urb->iso_frame_desc[i].status);
1131 bytes = urb->iso_frame_desc[i].actual_length;
1132 if (subs->stream_offset_adj > 0) {
1133 unsigned int adj = min(subs->stream_offset_adj, bytes);
1136 subs->stream_offset_adj -= adj;
1138 frames = bytes / stride;
1139 if (!subs->txfr_quirk)
1140 bytes = frames * stride;
1141 if (bytes % (runtime->sample_bits >> 3) != 0) {
1142 int oldbytes = bytes;
1143 bytes = frames * stride;
1144 dev_warn_ratelimited(&subs->dev->dev,
1145 "Corrected urb data len. %d->%d\n",
1148 /* update the current pointer */
1149 spin_lock_irqsave(&subs->lock, flags);
1150 oldptr = subs->hwptr_done;
1151 subs->hwptr_done += bytes;
1152 if (subs->hwptr_done >= subs->buffer_bytes)
1153 subs->hwptr_done -= subs->buffer_bytes;
1154 frames = (bytes + (oldptr % stride)) / stride;
1155 subs->transfer_done += frames;
1156 if (subs->transfer_done >= runtime->period_size) {
1157 subs->transfer_done -= runtime->period_size;
1161 /* realign last_frame_number */
1162 subs->last_frame_number = current_frame_number;
1164 spin_unlock_irqrestore(&subs->lock, flags);
1165 /* copy a data chunk */
1166 if (oldptr + bytes > subs->buffer_bytes) {
1167 unsigned int bytes1 = subs->buffer_bytes - oldptr;
1169 memcpy(runtime->dma_area + oldptr, cp, bytes1);
1170 memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
1172 memcpy(runtime->dma_area + oldptr, cp, bytes);
1177 snd_pcm_period_elapsed(subs->pcm_substream);
1180 static void urb_ctx_queue_advance(struct snd_usb_substream *subs,
1181 struct urb *urb, unsigned int bytes)
1183 struct snd_urb_ctx *ctx = urb->context;
1185 ctx->queued += bytes;
1186 subs->inflight_bytes += bytes;
1187 subs->hwptr_done += bytes;
1188 if (subs->hwptr_done >= subs->buffer_bytes)
1189 subs->hwptr_done -= subs->buffer_bytes;
1192 static inline void fill_playback_urb_dsd_dop(struct snd_usb_substream *subs,
1193 struct urb *urb, unsigned int bytes)
1195 struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1196 unsigned int dst_idx = 0;
1197 unsigned int src_idx = subs->hwptr_done;
1198 unsigned int wrap = subs->buffer_bytes;
1199 u8 *dst = urb->transfer_buffer;
1200 u8 *src = runtime->dma_area;
1201 u8 marker[] = { 0x05, 0xfa };
1202 unsigned int queued = 0;
1205 * The DSP DOP format defines a way to transport DSD samples over
1206 * normal PCM data endpoints. It requires stuffing of marker bytes
1207 * (0x05 and 0xfa, alternating per sample frame), and then expects
1208 * 2 additional bytes of actual payload. The whole frame is stored
1211 * Hence, for a stereo transport, the buffer layout looks like this,
1212 * where L refers to left channel samples and R to right.
1214 * L1 L2 0x05 R1 R2 0x05 L3 L4 0xfa R3 R4 0xfa
1215 * L5 L6 0x05 R5 R6 0x05 L7 L8 0xfa R7 R8 0xfa
1221 if (++subs->dsd_dop.byte_idx == 3) {
1222 /* frame boundary? */
1223 dst[dst_idx++] = marker[subs->dsd_dop.marker];
1225 subs->dsd_dop.byte_idx = 0;
1227 if (++subs->dsd_dop.channel % runtime->channels == 0) {
1228 /* alternate the marker */
1229 subs->dsd_dop.marker++;
1230 subs->dsd_dop.marker %= ARRAY_SIZE(marker);
1231 subs->dsd_dop.channel = 0;
1234 /* stuff the DSD payload */
1235 int idx = (src_idx + subs->dsd_dop.byte_idx - 1) % wrap;
1237 if (subs->cur_audiofmt->dsd_bitrev)
1238 dst[dst_idx++] = bitrev8(src[idx]);
1240 dst[dst_idx++] = src[idx];
1245 urb_ctx_queue_advance(subs, urb, queued);
1248 /* copy bit-reversed bytes onto transfer buffer */
1249 static void fill_playback_urb_dsd_bitrev(struct snd_usb_substream *subs,
1250 struct urb *urb, unsigned int bytes)
1252 struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1253 const u8 *src = runtime->dma_area;
1254 u8 *buf = urb->transfer_buffer;
1255 int i, ofs = subs->hwptr_done;
1257 for (i = 0; i < bytes; i++) {
1258 *buf++ = bitrev8(src[ofs]);
1259 if (++ofs >= subs->buffer_bytes)
1263 urb_ctx_queue_advance(subs, urb, bytes);
1266 static void copy_to_urb(struct snd_usb_substream *subs, struct urb *urb,
1267 int offset, int stride, unsigned int bytes)
1269 struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1271 if (subs->hwptr_done + bytes > subs->buffer_bytes) {
1272 /* err, the transferred area goes over buffer boundary. */
1273 unsigned int bytes1 = subs->buffer_bytes - subs->hwptr_done;
1275 memcpy(urb->transfer_buffer + offset,
1276 runtime->dma_area + subs->hwptr_done, bytes1);
1277 memcpy(urb->transfer_buffer + offset + bytes1,
1278 runtime->dma_area, bytes - bytes1);
1280 memcpy(urb->transfer_buffer + offset,
1281 runtime->dma_area + subs->hwptr_done, bytes);
1284 urb_ctx_queue_advance(subs, urb, bytes);
1287 static unsigned int copy_to_urb_quirk(struct snd_usb_substream *subs,
1288 struct urb *urb, int stride,
1291 __le32 packet_length;
1294 /* Put __le32 length descriptor at start of each packet. */
1295 for (i = 0; i < urb->number_of_packets; i++) {
1296 unsigned int length = urb->iso_frame_desc[i].length;
1297 unsigned int offset = urb->iso_frame_desc[i].offset;
1299 packet_length = cpu_to_le32(length);
1300 offset += i * sizeof(packet_length);
1301 urb->iso_frame_desc[i].offset = offset;
1302 urb->iso_frame_desc[i].length += sizeof(packet_length);
1303 memcpy(urb->transfer_buffer + offset,
1304 &packet_length, sizeof(packet_length));
1305 copy_to_urb(subs, urb, offset + sizeof(packet_length),
1308 /* Adjust transfer size accordingly. */
1309 bytes += urb->number_of_packets * sizeof(packet_length);
1313 static void prepare_playback_urb(struct snd_usb_substream *subs,
1316 struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1317 struct snd_usb_endpoint *ep = subs->data_endpoint;
1318 struct snd_urb_ctx *ctx = urb->context;
1319 unsigned int counts, frames, bytes;
1320 int i, stride, period_elapsed = 0;
1321 unsigned long flags;
1323 stride = ep->stride;
1327 urb->number_of_packets = 0;
1328 spin_lock_irqsave(&subs->lock, flags);
1329 subs->frame_limit += ep->max_urb_frames;
1330 for (i = 0; i < ctx->packets; i++) {
1331 counts = snd_usb_endpoint_next_packet_size(ep, ctx, i);
1332 /* set up descriptor */
1333 urb->iso_frame_desc[i].offset = frames * stride;
1334 urb->iso_frame_desc[i].length = counts * stride;
1336 urb->number_of_packets++;
1337 subs->transfer_done += counts;
1338 if (subs->transfer_done >= runtime->period_size) {
1339 subs->transfer_done -= runtime->period_size;
1340 subs->frame_limit = 0;
1342 if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
1343 if (subs->transfer_done > 0) {
1344 /* FIXME: fill-max mode is not
1346 frames -= subs->transfer_done;
1347 counts -= subs->transfer_done;
1348 urb->iso_frame_desc[i].length =
1350 subs->transfer_done = 0;
1353 if (i < ctx->packets) {
1354 /* add a transfer delimiter */
1355 urb->iso_frame_desc[i].offset =
1357 urb->iso_frame_desc[i].length = 0;
1358 urb->number_of_packets++;
1363 /* finish at the period boundary or after enough frames */
1364 if ((period_elapsed ||
1365 subs->transfer_done >= subs->frame_limit) &&
1366 !snd_usb_endpoint_implicit_feedback_sink(ep))
1369 bytes = frames * stride;
1371 if (unlikely(ep->cur_format == SNDRV_PCM_FORMAT_DSD_U16_LE &&
1372 subs->cur_audiofmt->dsd_dop)) {
1373 fill_playback_urb_dsd_dop(subs, urb, bytes);
1374 } else if (unlikely(ep->cur_format == SNDRV_PCM_FORMAT_DSD_U8 &&
1375 subs->cur_audiofmt->dsd_bitrev)) {
1376 fill_playback_urb_dsd_bitrev(subs, urb, bytes);
1379 if (!subs->tx_length_quirk)
1380 copy_to_urb(subs, urb, 0, stride, bytes);
1382 bytes = copy_to_urb_quirk(subs, urb, stride, bytes);
1383 /* bytes is now amount of outgoing data */
1386 subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1388 if (subs->trigger_tstamp_pending_update) {
1389 /* this is the first actual URB submitted,
1390 * update trigger timestamp to reflect actual start time
1392 snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
1393 subs->trigger_tstamp_pending_update = false;
1396 spin_unlock_irqrestore(&subs->lock, flags);
1397 urb->transfer_buffer_length = bytes;
1399 snd_pcm_period_elapsed(subs->pcm_substream);
1403 * process after playback data complete
1404 * - decrease the delay count again
1406 static void retire_playback_urb(struct snd_usb_substream *subs,
1409 unsigned long flags;
1410 struct snd_urb_ctx *ctx = urb->context;
1412 spin_lock_irqsave(&subs->lock, flags);
1414 if (subs->inflight_bytes >= ctx->queued)
1415 subs->inflight_bytes -= ctx->queued;
1417 subs->inflight_bytes = 0;
1420 subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1421 spin_unlock_irqrestore(&subs->lock, flags);
1424 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream,
1427 struct snd_usb_substream *subs = substream->runtime->private_data;
1431 case SNDRV_PCM_TRIGGER_START:
1432 subs->trigger_tstamp_pending_update = true;
1434 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1435 snd_usb_endpoint_set_callback(subs->data_endpoint,
1436 prepare_playback_urb,
1437 retire_playback_urb,
1439 if (cmd == SNDRV_PCM_TRIGGER_START) {
1440 err = start_endpoints(subs);
1442 snd_usb_endpoint_set_callback(subs->data_endpoint,
1448 dev_dbg(&subs->dev->dev, "%d:%d Start Playback PCM\n",
1449 subs->cur_audiofmt->iface,
1450 subs->cur_audiofmt->altsetting);
1452 case SNDRV_PCM_TRIGGER_SUSPEND:
1453 case SNDRV_PCM_TRIGGER_STOP:
1454 stop_endpoints(subs);
1455 snd_usb_endpoint_set_callback(subs->data_endpoint,
1458 dev_dbg(&subs->dev->dev, "%d:%d Stop Playback PCM\n",
1459 subs->cur_audiofmt->iface,
1460 subs->cur_audiofmt->altsetting);
1462 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1463 /* keep retire_data_urb for delay calculation */
1464 snd_usb_endpoint_set_callback(subs->data_endpoint,
1466 retire_playback_urb,
1469 dev_dbg(&subs->dev->dev, "%d:%d Pause Playback PCM\n",
1470 subs->cur_audiofmt->iface,
1471 subs->cur_audiofmt->altsetting);
1478 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream,
1482 struct snd_usb_substream *subs = substream->runtime->private_data;
1485 case SNDRV_PCM_TRIGGER_START:
1486 err = start_endpoints(subs);
1490 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1491 snd_usb_endpoint_set_callback(subs->data_endpoint,
1492 NULL, retire_capture_urb,
1494 subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1496 dev_dbg(&subs->dev->dev, "%d:%d Start Capture PCM\n",
1497 subs->cur_audiofmt->iface,
1498 subs->cur_audiofmt->altsetting);
1500 case SNDRV_PCM_TRIGGER_SUSPEND:
1501 case SNDRV_PCM_TRIGGER_STOP:
1502 stop_endpoints(subs);
1504 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1505 snd_usb_endpoint_set_callback(subs->data_endpoint,
1508 dev_dbg(&subs->dev->dev, "%d:%d Stop Capture PCM\n",
1509 subs->cur_audiofmt->iface,
1510 subs->cur_audiofmt->altsetting);
1517 static const struct snd_pcm_ops snd_usb_playback_ops = {
1518 .open = snd_usb_pcm_open,
1519 .close = snd_usb_pcm_close,
1520 .hw_params = snd_usb_hw_params,
1521 .hw_free = snd_usb_hw_free,
1522 .prepare = snd_usb_pcm_prepare,
1523 .trigger = snd_usb_substream_playback_trigger,
1524 .sync_stop = snd_usb_pcm_sync_stop,
1525 .pointer = snd_usb_pcm_pointer,
1528 static const struct snd_pcm_ops snd_usb_capture_ops = {
1529 .open = snd_usb_pcm_open,
1530 .close = snd_usb_pcm_close,
1531 .hw_params = snd_usb_hw_params,
1532 .hw_free = snd_usb_hw_free,
1533 .prepare = snd_usb_pcm_prepare,
1534 .trigger = snd_usb_substream_capture_trigger,
1535 .sync_stop = snd_usb_pcm_sync_stop,
1536 .pointer = snd_usb_pcm_pointer,
1539 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
1541 const struct snd_pcm_ops *ops;
1543 ops = stream == SNDRV_PCM_STREAM_PLAYBACK ?
1544 &snd_usb_playback_ops : &snd_usb_capture_ops;
1545 snd_pcm_set_ops(pcm, stream, ops);
1548 void snd_usb_preallocate_buffer(struct snd_usb_substream *subs)
1550 struct snd_pcm *pcm = subs->stream->pcm;
1551 struct snd_pcm_substream *s = pcm->streams[subs->direction].substream;
1552 struct device *dev = subs->dev->bus->sysdev;
1554 if (snd_usb_use_vmalloc)
1555 snd_pcm_set_managed_buffer(s, SNDRV_DMA_TYPE_VMALLOC,
1558 snd_pcm_set_managed_buffer(s, SNDRV_DMA_TYPE_DEV_SG,
1559 dev, 64*1024, 512*1024);