Allow for checks on a specific USB audio device to see if a requested PCM format is supported. This is needed for support for when playback is initiated by the ASoC USB backend path.
Signed-off-by: Wesley Cheng quic_wcheng@quicinc.com --- sound/usb/card.c | 19 +++++++++++++++++++ sound/usb/card.h | 3 +++ 2 files changed, 22 insertions(+)
diff --git a/sound/usb/card.c b/sound/usb/card.c index 396e5a34e23b..9b8d2ed308c8 100644 --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -133,6 +133,25 @@ int snd_usb_unregister_vendor_ops(void) } EXPORT_SYMBOL_GPL(snd_usb_unregister_vendor_ops);
+struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx, + struct snd_pcm_hw_params *params, int direction) +{ + struct snd_usb_stream *as; + struct snd_usb_substream *subs = NULL; + const struct audioformat *fmt; + + if (usb_chip[card_idx] && enable[card_idx]) { + list_for_each_entry(as, &usb_chip[card_idx]->pcm_list, list) { + subs = &as->substream[direction]; + fmt = find_substream_format(subs, params); + if (fmt) + return as; + } + } + + return 0; +} + /* * disconnect streams * called from usb_audio_disconnect() diff --git a/sound/usb/card.h b/sound/usb/card.h index a785bb256b0d..d4936b6054fc 100644 --- a/sound/usb/card.h +++ b/sound/usb/card.h @@ -213,4 +213,7 @@ struct snd_usb_vendor_ops {
int snd_usb_register_vendor_ops(struct snd_usb_vendor_ops *ops); int snd_usb_unregister_vendor_ops(void); + +struct snd_usb_stream *snd_usb_find_suppported_substream(int card_idx, + struct snd_pcm_hw_params *params, int direction); #endif /* __USBAUDIO_CARD_H */