mb/google/dedede: Generate MS0X entry and provide variant hook

BUG=b:245426120
BRANCH=firmware-dedede-13606.B
TEST=emerge-dedede coreboot
     check SSDT table has MS0X entry
     Scope (\_SB)
    {
        Method (MS0X, 1, Serialized)
        {
            If ((Arg0 == One)) {}
            Else
            {
            }
        }
    }

Change-Id: Id01089531503e62231c5ab19e4cd8056198b9acb
Signed-off-by: Tony Huang <tony-huang@quanta.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67373
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>

src/mainboard/google/dedede/mainboard.c

@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */
 
 #include <acpi/acpi.h>
+#include <acpi/acpigen.h>
 #include <baseboard/variants.h>
 #include <console/console.h>
 #include <device/device.h>
@@ -63,10 +64,46 @@ static unsigned long mainboard_write_acpi_tables(
 	return current;
 }
 
+static void mainboard_generate_s0ix_hook(void)
+{
+	acpigen_write_if_lequal_op_int(ARG0_OP, 1);
+	variant_generate_s0ix_hook(S0IX_ENTRY);
+	acpigen_write_else();
+	variant_generate_s0ix_hook(S0IX_EXIT);
+	acpigen_write_if_end();
+}
+
+static void mainboard_fill_ssdt(const struct device *dev)
+{
+
+	acpigen_write_scope("\\_SB");
+	acpigen_write_method_serialized("MS0X", 1);
+	mainboard_generate_s0ix_hook();
+	acpigen_write_method_end(); /* Method */
+	acpigen_write_scope_end(); /* Scope */
+
+}
+
+void __weak variant_generate_s0ix_hook(enum s0ix_entry entry)
+{
+
+	/* Add board-specific MS0X entries */
+	/*
+	if (s0ix_entry == S0IX_ENTRY) {
+		implement variant operations here
+	}
+	if (s0ix_entry == S0IX_EXIT) {
+		implement variant operations here
+	}
+	*/
+}
+
+
 static void mainboard_enable(struct device *dev)
 {
 	dev->ops->init = mainboard_dev_init;
 	dev->ops->write_acpi_tables = mainboard_write_acpi_tables;
+	dev->ops->acpi_fill_ssdt = mainboard_fill_ssdt;
 }
 
 struct chip_operations mainboard_ops = {

src/mainboard/google/dedede/variants/baseboard/include/baseboard/variants.h

@@ -15,6 +15,11 @@ const struct pad_config *variant_early_gpio_table(size_t *num);
 const struct pad_config *variant_sleep_gpio_table(size_t *num);
 const struct pad_config *variant_override_gpio_table(size_t *num);
 
+enum s0ix_entry {
+	S0IX_EXIT,
+	S0IX_ENTRY,
+};
+
 /**
  * Get board's Hardware features as defined in FW_CONFIG
  *
@@ -44,4 +49,6 @@ void variant_devtree_update(void);
 
 /* Modify LTE devictree settings during ramstage. */
 void update_lte_device(struct acpi_gpio *lte_reset_gpio, struct acpi_gpio *lte_enable_gpio);
+
+void variant_generate_s0ix_hook(enum s0ix_entry);
 #endif /*__BASEBOARD_VARIANTS_H__ */