sound/usb/endpoint.c

58  * There are two different types of endpoints in audio applications.
77  * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
86  * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
157  * Return the number of samples to be sent in the next packet
186  * Return the number of samples to be sent in the next packet
214  * in the next packet
447  * from ep->ready_playback_urbs and in case there aren't any available
452  * is that host controllers don't guarantee the order in which they return
455  * This function is used both for implicit feedback endpoints and in low-
491 		/* call the data handler to fill in playback data */
557 		/* in low-latency and implicit-feedback modes, push back the
569 		/* in non-lowlatency mode, no error handling for prepare */
603  * The objects are released altogether in snd_usb_endpoint_free_all()
1108 		 * When operating in DSD DOP mode, the size of a sample frame
1109 		 * in hardware differs from the actual physical format width
1135 	/* Round up freqmax to nearest integer in order to calculate maximum
1142 	 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125)
1147 	 * USB high speed, noting that ep->freqmax is in units of
1148 	 * frames per packet in Q16.16 format.)
1185 	 * to tell in advance where the next period will end, and we don't
1201 	 * a period fits as evenly as possible in the smallest number of
1220 		/* how many packets are needed in each URB? */
1223 		/* limit the number of frames in a single URB */
1372 	/* calculate the frequency in 16.16 format */
1394 	/* some unit conversions in runtime */
1547  * Returns an error if the URB submission failed, 0 in all other cases.
1658  * @keep_pending: keep in-flight URBs
1719 	struct snd_usb_iface_ref *ip, *in;
1725 	list_for_each_entry_safe(ip, in, &chip->iface_ref_list, list)
1753 	 * In case the endpoint is operating in implicit feedback mode, prepare
1798 		 * in case the number of channels differ between the implicitly
1820 	 * Full speed devices report feedback values in 10.14 format as samples
1821 	 * per frame, high speed devices in 16.16 format as samples per
1880 		 * This value is referred to in prepare_playback_urb().