TGL boards using the Type-C subsystem for USB Type-C ports without a
retimer attached may require a DC bias on the aux lines for certain
modes to work. This patch adds native coreboot support for programming
the IOM to handle this DC bias via a simple devicetree
setting. Previously a UPD was required to tell the FSP which GPIOs were
used for the pullup and pulldown biases, but the API for this UPD was
effectively undocumented.
BUG=b:174116646
TEST=Verified on volteer2 that a Type-C flash drive is enumerated
succesfully on all ports. Verified all major power flows (boot, reboot,
powerdown and S0ix/suspend) still work as expected.
Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: I70e36a41e760f4a435511c147cc5744a77dbccc0
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51649
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
59a621abc7