mb/google/dedede: Add HPD GPIOs on dexi variant

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.

BUG=b:303533815
BRANCH=dedede
TEST=On dexi, 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: Ib4fc071cac98a542072ffbeb6943bff4c988554c
Signed-off-by: Kenneth Chan <kenneth.chan@quanta.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78450
Reviewed-by: Sheng-Liang Pan <sheng-liang.pan@quanta.corp-partner.google.com>
Reviewed-by: Ren Kuo <ren.kuo@quanta.corp-partner.google.com>
Reviewed-by: Eric Lai <ericllai@google.com>
Reviewed-by: David Wu <david_wu@quanta.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/src/mainboard/google/dedede/variants/dexi/gpio.c b/src/mainboard/google/dedede/variants/dexi/gpio.c
index 89a7a77feb..2998592756 100644
--- a/src/mainboard/google/dedede/variants/dexi/gpio.c
+++ b/src/mainboard/google/dedede/variants/dexi/gpio.c
@@ -91,3 +91,18 @@ const struct pad_config *variant_override_gpio_table(size_t *num)
 	*num = ARRAY_SIZE(gpio_table);
 	return gpio_table;
 }
+
+static const gpio_t hpd_gpios[] = {
+	/* HDMI1 */
+	GPP_A17,
+	/* HDMI2 */
+	GPP_A16,
+	/* USB C0 */
+	GPP_B23,
+};
+
+const gpio_t *variant_hpd_gpios(size_t *num)
+{
+	*num = ARRAY_SIZE(hpd_gpios);
+	return hpd_gpios;
+}