mb/google/brya/var/nereid: Configure descriptor for either Type-C or HDMI

Some bytes in the descriptor need to be set differently for Type-C and
HDMI. To allow using a single firmware variant for both cases, update
the descriptor at runtime based on fw_config. This is a temporary
workaround while we find a better solution.

The byte values were determined by changing the following CSE strap and
comparing the generated descriptors:
Type-C: TypeCPort2Config = "No Thunderbolt"
HDMI:   TypeCPort2Config = "DP Fixed Connection"

The default value before updating the descriptor is Type-C, but this was
chosen arbitrarily.

BUG=b:226848617
TEST=Type-C and HDMI both work on nereid with fw_config set correctly.

Change-Id: I2cc230e3bd35816c81989ae7e01df5d2c152062e
Signed-off-by: Reka Norman <rekanorman@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63366
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Sam McNally <sammc@google.com>

0 files changed, 0 insertions, 0 deletions