src/soc/intel/common/acpi_wake_source.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2015 Google Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <arch/acpi.h>
#include <bootstate.h>
#include <cbmem.h>
#include <console/console.h>
#include <soc/nvs.h>
#include <stdint.h>
#include <stdlib.h>
#include "acpi.h"

__attribute__((weak)) int soc_fill_acpi_wake(uint32_t *pm1, uint32_t **gpe0)
{
	return -1;
}

/* Save wake source data for ACPI _SWS methods in NVS */
static void acpi_save_wake_source(void *unused)
{
	global_nvs_t *gnvs = cbmem_find(CBMEM_ID_ACPI_GNVS);
	uint32_t pm1, *gpe0;
	int gpe_reg, gpe_reg_count;
	int reg_size = sizeof(uint32_t) * 8;

	if (!gnvs)
		return;

	gnvs->pm1i = -1;
	gnvs->gpei = -1;

	gpe_reg_count = soc_fill_acpi_wake(&pm1, &gpe0);
	if (gpe_reg_count < 0)
		return;

	/* Scan for first set bit in PM1 */
	for (gnvs->pm1i = 0; gnvs->pm1i < reg_size; gnvs->pm1i++) {
		if (pm1 & 1)
			break;
		pm1 >>= 1;
	}

	/* If unable to determine then return -1 */
	if (gnvs->pm1i >= 16)
		gnvs->pm1i = -1;

	/* Scan for first set bit in GPE registers */
	for (gpe_reg = 0; gpe_reg < gpe_reg_count; gpe_reg++) {
		uint32_t gpe = gpe0[gpe_reg];
		int start = gpe_reg * reg_size;
		int end = start + reg_size;

		if (gpe == 0) {
			if (!gnvs->gpei)
				gnvs->gpei = end;
			continue;
		}

		for (gnvs->gpei = start; gnvs->gpei < end; gnvs->gpei++) {
			if (gpe & 1)
				break;
			gpe >>= 1;
		}
	}

	/* If unable to determine then return -1 */
	if (gnvs->gpei >= gpe_reg_count * reg_size)
		gnvs->gpei = -1;

	printk(BIOS_DEBUG, "ACPI _SWS is PM1 Index %lld GPE Index %lld\n",
	       (long long)gnvs->pm1i, (long long)gnvs->gpei);
}

BOOT_STATE_INIT_ENTRY(BS_OS_RESUME, BS_ON_ENTRY, acpi_save_wake_source, NULL);