[S] Change in coreboot[main]: mb/google/dedede/var/taranza: Add wait for HPD function

[Sheng-Liang Pan (Code Review)]

Sheng-Liang Pan has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/78265?usp=email )

Change subject: mb/google/dedede/var/taranza: Add wait for HPD function
......................................................................

mb/google/dedede/var/taranza: Add wait for HPD function

Add delay to wait for HPD ready to continue boot in ramstage to
avoid no display in DEV screen and recovery screen.

BUG=b:303547403
TEST=type-c minitor can display in DEV screen and recovery screen

Signed-off-by: Sheng-Liang Pan 
Change-Id: Iefe3a819c94cd1e89c8e0a87fe221e4b5dbafe12
---
M src/mainboard/google/dedede/variants/taranza/ramstage.c
1 file changed, 40 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/65/78265/1

diff --git a/src/mainboard/google/dedede/variants/taranza/ramstage.c b/src/mainboard/google/dedede/variants/taranza/ramstage.c
index afb3fc7..c2b3629 100644
--- a/src/mainboard/google/dedede/variants/taranza/ramstage.c
+++ b/src/mainboard/google/dedede/variants/taranza/ramstage.c
@@ -1,6 +1,34 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */

+#include <bootmode.h>
+#include <baseboard/gpio.h>
 #include <baseboard/variants.h>
+#include <console/console.h>
+#include <delay.h>
+#include <ec/google/chromeec/ec.h>
+#include <gpio.h>
+#include <intelblocks/gpio.h>
+#include <timer.h>
+
+#define GPIO_USB_HPD GPP_A16
+
+static void wait_for_hpd(gpio_t gpio, long timeout)
+{
+	struct stopwatch sw;
+
+	printk(BIOS_INFO, "Waiting for HPD\n");
+	stopwatch_init_msecs_expire(&sw, timeout);
+	while (!gpio_get(gpio)) {
+		if (stopwatch_expired(&sw)) {
+			printk(BIOS_WARNING,
+			       "HPD not ready after %ldms. Abort.\n", timeout);
+			return;
+		}
+		mdelay(200);
+	}
+	printk(BIOS_INFO, "HPD ready after %lld ms\n",
+	       stopwatch_duration_msecs(&sw));
+}

/*
  * Psys_pmax considerations
@@ -33,3 +61,15 @@
 {
    variant_update_psys_power_limits(&psys_config);
 }
+
+void variant_display_init(void)
+{
+	static const long display_timeout_ms = 3000;
+
+	if (display_init_required()
+		&& !gpio_get(GPIO_USB_HPD)) {
+		/* This has to be done before FSP-S runs. */
+		if (google_chromeec_wait_for_displayport(display_timeout_ms))
+			wait_for_hpd(GPIO_USB_HPD, display_timeout_ms);
+		}
+}