From c476c4d5b9f53f01c0f0b9673d3b9f0a29a6ae64 Mon Sep 17 00:00:00 2001
From: Hope Wang <hope.wang@mediatek.corp-partner.google.com>
Date: Thu, 26 Dec 2024 17:50:55 +0800
Subject: [PATCH] soc/mediatek/mt8196: Delay 0.5ms after enabling PMIF SPMI SW
 interface

The initialization process of SPMI requires a certain amount of time
(0.5ms) to ensure all components are correctly configured and
synchronized. Otherwise, if the SPMI calibration fails, it will result
in the non-serial firmware failing to boot.

TEST=Build pass, non-serial firmware boot ok.
BUG=b:341054056

Change-Id: I63df384061e4ed2629238f1843decd18d1ad1ac4
Signed-off-by: Hope Wang <hope.wang@mediatek.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/85799
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Reviewed-by: Yidi Lin <yidilin@google.com>
---
 src/soc/mediatek/mt8196/pmif_spmi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/soc/mediatek/mt8196/pmif_spmi.c b/src/soc/mediatek/mt8196/pmif_spmi.c
index d00afe115d..e646816774 100644
--- a/src/soc/mediatek/mt8196/pmif_spmi.c
+++ b/src/soc/mediatek/mt8196/pmif_spmi.c
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only OR MIT */
 
 #include <console/console.h>
+#include <delay.h>
 #include <device/mmio.h>
 #include <gpio.h>
 #include <soc/addressmap.h>
@@ -285,6 +286,7 @@ static void pmif_spmi_enable_swinf(struct pmif *arb)
 {
 	write32(&arb->mtk_pmif->inf_en, PMIF_SPMI_SW_CHAN);
 	write32(&arb->mtk_pmif->arb_en, PMIF_SPMI_SW_CHAN);
+	udelay(500);
 	printk(BIOS_INFO, "%s done\n", __func__);
 }