From 69b054137502008c09d499d0d4773cf2d9388304 Mon Sep 17 00:00:00 2001
From: Keith Hui <buurin@gmail.com>
Date: Sat, 26 Jul 2025 23:57:51 -0400
Subject: [PATCH] sio/nuvoton/nct6779d: Add power loss resume support

Adds long overdue power loss resume support to nct6779d using
code from nct5572d.

Change-Id: I91bf01a176716b97c6ca6a841c68cd3d4a39d23d
Signed-off-by: Keith Hui <buurin@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/88701
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
---
 src/superio/nuvoton/nct6779d/Kconfig   |  1 +
 src/superio/nuvoton/nct6779d/superio.c | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/src/superio/nuvoton/nct6779d/Kconfig b/src/superio/nuvoton/nct6779d/Kconfig
index ce2af16627..9f20f7b936 100644
--- a/src/superio/nuvoton/nct6779d/Kconfig
+++ b/src/superio/nuvoton/nct6779d/Kconfig
@@ -3,3 +3,4 @@
 config SUPERIO_NUVOTON_NCT6779D
 	bool
 	select SUPERIO_NUVOTON_COMMON_PRE_RAM
+	select HAVE_POWER_STATE_AFTER_FAILURE
diff --git a/src/superio/nuvoton/nct6779d/superio.c b/src/superio/nuvoton/nct6779d/superio.c
index 13604769ab..0381be2beb 100644
--- a/src/superio/nuvoton/nct6779d/superio.c
+++ b/src/superio/nuvoton/nct6779d/superio.c
@@ -2,13 +2,20 @@
 
 #include <device/device.h>
 #include <device/pnp.h>
+#include <option.h>
 #include <pc80/keyboard.h>
 #include <superio/conf_mode.h>
 
 #include "nct6779d.h"
 
+#define MAINBOARD_POWER_OFF	0
+#define MAINBOARD_POWER_ON	1
+#define MAINBOARD_POWER_KEEP	2
+
 static void nct6779d_init(struct device *dev)
 {
+	uint8_t byte, power_status;
+
 	if (!dev->enabled)
 		return;
 
@@ -17,6 +24,21 @@ static void nct6779d_init(struct device *dev)
 	case NCT6779D_KBC:
 		pc_keyboard_init(NO_AUX_DEVICE);
 		break;
+	case NCT6779D_ACPI:
+		/* Set power state after power fail */
+		power_status = get_uint_option("power_on_after_fail",
+				CONFIG_MAINBOARD_POWER_FAILURE_STATE);
+		pnp_enter_conf_mode(dev);
+		pnp_set_logical_device(dev);
+		byte = pnp_read_config(dev, 0xe4) & ~0x60;
+		if (power_status == MAINBOARD_POWER_ON)
+			byte |= (MAINBOARD_POWER_ON << 5);
+		else if (power_status == MAINBOARD_POWER_KEEP)
+			byte |= (MAINBOARD_POWER_KEEP << 5);
+		pnp_write_config(dev, 0xe4, byte);
+		pnp_exit_conf_mode(dev);
+		printk(BIOS_INFO, "set power %s after power fail\n", power_status ? "on" : "off");
+		break;
 	}
 }