path: root/drivers/acpi/property.c

/*
 * ACPI device specific properties support.
 *
 * Copyright (C) 2014, Intel Corporation
 * All rights reserved.
 *
 * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
 *          Darren Hart <dvhart@linux.intel.com>
 *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/export.h>

#include "internal.h"

static int acpi_data_get_property_array(struct acpi_device_data *data,
					const char *name,
					acpi_object_type type,
					const union acpi_object **obj);

/* ACPI _DSD device properties UUID: daffd814-6eba-4d8c-8a91-bc9bbf4aa301 */
static const u8 prp_uuid[16] = {
	0x14, 0xd8, 0xff, 0xda, 0xba, 0x6e, 0x8c, 0x4d,
	0x8a, 0x91, 0xbc, 0x9b, 0xbf, 0x4a, 0xa3, 0x01
};
/* ACPI _DSD data subnodes UUID: dbb8e3e6-5886-4ba6-8795-1319f52a966b */
static const u8 ads_uuid[16] = {
	0xe6, 0xe3, 0xb8, 0xdb, 0x86, 0x58, 0xa6, 0x4b,
	0x87, 0x95, 0x13, 0x19, 0xf5, 0x2a, 0x96, 0x6b
};

static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
					   const union acpi_object *desc,
					   struct acpi_device_data *data,
					   struct fwnode_handle *parent);
static bool acpi_extract_properties(const union acpi_object *desc,
				    struct acpi_device_data *data);

static bool acpi_nondev_subnode_extract(const union acpi_object *desc,
					acpi_handle handle,
					const union acpi_object *link,
					struct list_head *list,
					struct fwnode_handle *parent)
{
	struct acpi_data_node *dn;
	bool result;

	dn = kzalloc(sizeof(*dn), GFP_KERNEL);
	if (!dn)
		return false;

	dn->name = link->package.elements[0].string.pointer;
	dn->fwnode.type = FWNODE_ACPI_DATA;
	dn->fwnode.ops = &acpi_fwnode_ops;
	dn->parent = parent;
	INIT_LIST_HEAD(&dn->data.subnodes);

	result = acpi_extract_properties(desc, &dn->data);

	if (handle) {
		acpi_handle scope;
		acpi_status status;

		/*
		 * The scope for the subnode object lookup is the one of the
		 * namespace node (device) containing the object that has
		 * returned the package.  That is, it's the scope of that
		 * object's parent.
		 */
		status = acpi_get_parent(handle, &scope);
		if (ACPI_SUCCESS(status)
		    && acpi_enumerate_nondev_subnodes(scope, desc, &dn->data,
						      &dn->fwnode))
			result = true;
	} else if (acpi_enumerate_nondev_subnodes(NULL, desc, &dn->data,
						  &dn->fwnode)) {
		result = true;
	}

	if (result) {
		dn->handle = handle;
		dn->data.pointer = desc;
		list_add_tail(&dn->sibling, list);
		return true;
	}

	kfree(dn);
	acpi_handle_debug(handle, "Invalid properties/subnodes data, skipping\n");
	return false;
}

static bool acpi_nondev_subnode_data_ok(acpi_handle handle,
					const union acpi_object *link,
					struct list_head *list,
					struct fwnode_handle *parent)
{
	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
	acpi_status status;

	status = acpi_evaluate_object_typed(handle, NULL, NULL