It's all right with me if people use my implementation of USB Power
Delivery in anything. This will make writing firmware for the PD Buddy
Dev a lot more reasonable, once it exists.
According to the USB Power Delivery Specification Revision 3.0, Version
1.1, section 7.2.3.1, we're not required to enter Sink Standby when
changing the negotiated voltage on a single PPS APDO. Now we don't.
This is done in the PE, so the DPM doesn't have to lift a finger to
avoid the unnecessary standby.
Now if we make a request for a PPS APDO, the SinkPPSPeriodicTimer is
run, forcing a new request to be made every 10 s. This is important
because without it, the Source Shall perform a Hard Reset 15 s after the
request is made.
The new tempate variable sets the data role, power role, and
specification revision in one fell swoop. It's used by the PE and DPM
alike for creating messages, and in the future it may have a part in
determining if we're doing PD 2.0 or 3.0.
This commit splits the old messages.h file into two, one private
(messages.h) and one public (pdb_msg.h). This new arrangement keeps the
old model of one message pool for all the PD Buddy firmware library, but
moves the macro for the number of objects it contains into a new file,
pdb_conf.h, placed at the project root. The pool itself is kept in the
new pdb_msg.h file, since the DPM may need to access it.
The new configuration file also contains the stack sizes for the PD
Buddy threads (some will be moved back to secrecy in the future once the
needed sizes are known, but the PE's stack size should be kept in
pdb_conf.h since user code needs that stack).
To do this, a couple of the events had to have their definitions moved
to lib/include/pdb_pe.h. This isn't a problem in and of itself, but if
more internal-use events are added to policy_engine.h there could be
trouble. To mitigate this, I added a comment as a reminder to make sure
any new events don't overlap the public ones defined elsewhere.
Not the static globals yet, just the public ones. I suppose this change
isn't technically necessary since the PD Buddy Sink is a single-port
device, but I want its firmware to be a shining example of how to use
the library.
/!\ BROKEN BUILD /!\
This commit moves the library code to the library directory. This
causes the firmware to not compile. A few changes were made to reduce
the nubmer of errors, but some errors just aren't going to go away until
I go ahead with the planned changes.
There are still a few things that the standard says we Shall do and we
don't, but it Works For Me™. I haven't implemented anything with
regards to GiveBack support, but that doesn't matter just yet. Our
handling of VDMs isn't quite right either. Anyway, it successfully
negotiates with so-called Split PDO power supplies, which is more than I
can say about some commercial products.
Clara Hobbs