[M] Change in coreboot[main]: mb/google/dedede: Wait for HPD on dibbi variants

[Reka Norman (Code Review)]

Attention is currently required from: Reka Norman.

Hello Sam McNally,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/78294?usp=email

to look at the new patch set (#2).

Change subject: mb/google/dedede: Wait for HPD on dibbi variants
......................................................................

mb/google/dedede: Wait for HPD on dibbi variants

Some Type-C monitors do not immediately assert HPD. If we enter FSP-S
before HDP is asserted, display initialisation may fail. So wait for
HPD.

This is similar to commit b40c6009141e ("mainboard/hatch: Fix puff DP
output on cold boots") on puff, except we don't use
google_chromeec_wait_for_displayport() since that EC command was removed
for TCPMv2 (https://crrev.com/c/4221975). Instead we use the HPD signals
only. By waiting for any HPD signal (Type-C or HDMI), we skip waiting if
HDMI is connected, which is the same behaviour as puff and fizz.

TEST=On dibbi, connect a display via a Type-C to HDMI dongle and check
the dev and recovery screens are now displayed correctly. Also check the
logs in the following cases:

Cold reboot in dev mode, Type-C to HDMI dongle:
HPD ready after 800 ms

Warm reboot in dev mode, Type-C to HDMI dongle:
HPD ready after 0 ms

Cold/warm reboot in dev mode, direct Type-C:
HPD ready after 0 ms

Cold/warm reboot in dev mode, direct HDMI:
HPD ready after 0 ms

Cold/warm reboot in dev mode, no display:
HPD not ready after 3000 ms. Abort.

Change-Id: Id4657b5d5a95a68ecbd9efcf3585cf96ad1e13e1
Signed-off-by: Reka Norman 
---
M src/mainboard/google/dedede/mainboard.c
M src/mainboard/google/dedede/variants/baseboard/gpio.c
M src/mainboard/google/dedede/variants/baseboard/include/baseboard/variants.h
M src/mainboard/google/dedede/variants/boxy/gpio.c
M src/mainboard/google/dedede/variants/dibbi/gpio.c
M src/mainboard/google/dedede/variants/taranza/gpio.c
6 files changed, 105 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/94/78294/2