cheza: Mux the 1st-plugged UFP port which is not a charger

There are 2 USB-C ports. A user may plug a USB-C to USB-A male
cable to one of the ports; then EC should mux the port from USB
hub to AP's primary USB controller, which is configured to do USB
peripheral mode only.

The policy is to mux the first-plugged UFP port to AP, with the
following exception:
* If the partner port does PD and it advertises the USB communications
  capable bit unset in the fixed-supply PDO, we believe the partner
  port is a pure charger.
* If the BC1.2 chip detects the partner is not a SDP or CDP , we
  believe the partner port is not a workstation.

Check the design doc at:
  http://go/cheza-hs-mux

BRANCH=none
BUG=b:74395451, b:110803836
TEST=Check the following scenario:
* Plug charger w/ PD to P0, plug C-to-A to P1, check P1 mux to AP.
* Plug charger through hub to P0, plug C-to-A to P1, check P1 mux to AP.
* Continue the above case, boot into kernel and check USB peripheral mode.
* Plug BC1.2 charger to P0, plug C-to-A to P1, check P1 mux to AP.
* Plug charger w/o PD to P0, plug C-to-A to P1, check P0 mux to AP.
* Swap P0 and P1 for the above cases and check the results.

Change-Id: I4034fa66c0b27cc48d0959bb3f1750690ad5e3f7
Signed-off-by: Wai-Hong Tam <waihong@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1105404
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>

0 files changed, 0 insertions, 0 deletions