ALSA: usb-audio: parse clock topology of UAC2 devices
Audio devices which comply to the UAC2 standard can export complex clock
topologies in its descriptors and set up links between them.
The entities that are defined are
- clock sources, which define the end-leafs.
- clock selectors, which act as switch to select one out of many
possible clocks sources.
- clock multipliers, which have an input clock source, and act as clock
source again. They can be used to derive one clock from another.
All sample rate changes, clock validity queries and the like must go to
clock source elements, while clock selectors and multipliers can be used
as terminal clock source.
The following patch adds a parser for these elements and functions to
iterate over the tree and find the leaf nodes (clock sources).
The samplerate set functions were moved to the new clock.c file.
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index 06ebf24..24d3319 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -40,9 +40,6 @@
int num_interfaces;
int num_suspended_intf;
- /* for audio class v2 */
- int clock_id;
-
struct list_head pcm_list; /* list of pcm streams */
int pcm_devs;
@@ -53,6 +50,8 @@
int setup; /* from the 'device_setup' module param */
int nrpacks; /* from the 'nrpacks' module param */
int async_unlink; /* from the 'async_unlink' module param */
+
+ struct usb_host_interface *ctrl_intf; /* the audio control interface */
};
/*