The upcoming SDCA (SoundWire Device Class Audio) specification defines a hiearchical encoding to interface with Class-defined capabilities,
typo hiearchical
ok
based on which audio function, entity, control and channel being used.
Can you please elaborate on what do these terms refer to?
Also can we have some documentation for this and how Linux is going to use it..
These are concepts in the SDCA draft spec, and that should be the reference. We worked with MIPI so that this spec will be available with a click-through agreement when ratified, for now it's only available to contributors per MIPI bylaws.
If you do not have access to this specification, then that's a real problem. Maybe you need to let Bard take care of this part as a co-maintainer?
The goal with this macro is to enable a first set of codecs drivers using these concepts to be released upstream. All you need to know at this point is that controls are defined in a hierarchical way and accessed with a read/write transaction from/to the address created with the following macro.
+/* v1.2 device - SDCA address mapping */ +#define SDW_SDCA_CTL(fun, ent, ctl, ch) (BIT(30) | \
(((fun) & 0x7) << 22) | \(((ent) & 0x40) << 15) | \(((ent) & 0x3f) << 7) | \(((ctl) & 0x30) << 15) | \(((ctl) & 0x0f) << 3) | \(((ch) & 0x38) << 12) | \((ch) & 0x07))how about adding an underscore to the arguments here:
#define SDW_SDCA_CTL(_fun, _ent, _ctl, _ch) and so on..
I checked the SoundWire defines and the vast majority of the macros don't use underscores, and when they do there's no consistency between 1 or 2 underscores.