// SPDX-License-Identifier: GPL-2.0-only

  /*
   * 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>

   */
  
  #include <linux/acpi.h>
  #include <linux/device.h>
  #include <linux/export.h>
  
  #include "internal.h"

  static int acpi_data_get_property_array(const struct acpi_device_data *data,

  					const char *name,
  					acpi_object_type type,
  					const union acpi_object **obj);

  /*
   * The GUIDs here are made equivalent to each other in order to avoid extra
   * complexity in the properties handling code, with the caveat that the
   * kernel will accept certain combinations of GUID and properties that are
   * not defined without a warning. For instance if any of the properties
   * from different GUID appear in a property list of another, it will be
   * accepted by the kernel. Firmware validation tools should catch these.
   */

  static const guid_t prp_guids[] = {
  	/* ACPI _DSD device properties GUID: daffd814-6eba-4d8c-8a91-bc9bbf4aa301 */

  	GUID_INIT(0xdaffd814, 0x6eba, 0x4d8c,

  		  0x8a, 0x91, 0xbc, 0x9b, 0xbf, 0x4a, 0xa3, 0x01),

  	/* Hotplug in D3 GUID: 6211e2c0-58a3-4af3-90e1-927a4e0c55a4 */
  	GUID_INIT(0x6211e2c0, 0x58a3, 0x4af3,
  		  0x90, 0xe1, 0x92, 0x7a, 0x4e, 0x0c, 0x55, 0xa4),

  	/* External facing port GUID: efcc06cc-73ac-4bc3-bff0-76143807c389 */
  	GUID_INIT(0xefcc06cc, 0x73ac, 0x4bc3,
  		  0xbf, 0xf0, 0x76, 0x14, 0x38, 0x07, 0xc3, 0x89),

  	/* Thunderbolt GUID for IMR_VALID: c44d002f-69f9-4e7d-a904-a7baabdf43f7 */
  	GUID_INIT(0xc44d002f, 0x69f9, 0x4e7d,
  		  0xa9, 0x04, 0xa7, 0xba, 0xab, 0xdf, 0x43, 0xf7),
  	/* Thunderbolt GUID for WAKE_SUPPORTED: 6c501103-c189-4296-ba72-9bf5a26ebe5d */
  	GUID_INIT(0x6c501103, 0xc189, 0x4296,
  		  0xba, 0x72, 0x9b, 0xf5, 0xa2, 0x6e, 0xbe, 0x5d),

  	/* Storage device needs D3 GUID: 5025030f-842f-4ab4-a561-99a5189762d0 */
  	GUID_INIT(0x5025030f, 0x842f, 0x4ab4,
  		  0xa5, 0x61, 0x99, 0xa5, 0x18, 0x97, 0x62, 0xd0),

  };

  /* ACPI _DSD data subnodes GUID: dbb8e3e6-5886-4ba6-8795-1319f52a966b */

  static const guid_t ads_guid =
  	GUID_INIT(0xdbb8e3e6, 0x5886, 0x4ba6,
  		  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.ops = &acpi_data_fwnode_ops;

  	dn->parent = parent;

  	INIT_LIST_HEAD(&dn->data.properties);

  	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
  ");

  	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, &buf,
  					    ACPI_TYPE_PACKAGE);
  	if (ACPI_FAILURE(status))
  		return false;

  	if (acpi_nondev_subnode_extract(buf.pointer, handle, link, list,
  					parent))

  		return true;

  	ACPI_FREE(buf.pointer);

  	return false;
  }

  static bool acpi_nondev_subnode_ok(acpi_handle scope,
  				   const union acpi_object *link,

  				   struct list_head *list,
  				   struct fwnode_handle *parent)

  {
  	acpi_handle handle;
  	acpi_status status;
  
  	if (!scope)
  		return false;
  
  	status = acpi_get_handle(scope, link->package.elements[1].string.pointer,
  				 &handle);
  	if (ACPI_FAILURE(status))
  		return false;

  	return acpi_nondev_subnode_data_ok(handle, link, list, parent);

  }

  static int acpi_add_nondev_subnodes(acpi_handle scope,
  				    const union acpi_object *links,

  				    struct list_head *list,
  				    struct fwnode_handle *parent)

  {
  	bool ret = false;
  	int i;
  
  	for (i = 0; i < links->package.count; i++) {

  		const union acpi_object *link, *desc;
  		acpi_handle handle;
  		bool result;

  
  		link = &links->package.elements[i];

  		/* Only two elements allowed. */
  		if (link->package.count != 2)
  			continue;
  
  		/* The first one must be a string. */
  		if (link->package.elements[0].type != ACPI_TYPE_STRING)
  			continue;
  
  		/* The second one may be a string, a reference or a package. */
  		switch (link->package.elements[1].type) {
  		case ACPI_TYPE_STRING:

  			result = acpi_nondev_subnode_ok(scope, link, list,
  							 parent);

  			break;
  		case ACPI_TYPE_LOCAL_REFERENCE:
  			handle = link->package.elements[1].reference.handle;

  			result = acpi_nondev_subnode_data_ok(handle, link, list,
  							     parent);

  			break;
  		case ACPI_TYPE_PACKAGE:
  			desc = &link->package.elements[1];

  			result = acpi_nondev_subnode_extract(desc, NULL, link,
  							     list, parent);

  			break;
  		default:
  			result = false;
  			break;
  		}
  		ret = ret || result;

  	}
  
  	return ret;
  }
  
  static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
  					   const union acpi_object *desc,

  					   struct acpi_device_data *data,
  					   struct fwnode_handle *parent)

  {
  	int i;

  	/* Look for the ACPI data subnodes GUID. */

  	for (i = 0; i < desc->package.count; i += 2) {

  		const union acpi_object *guid, *links;

  		guid = &desc->package.elements[i];

  		links = &desc->package.elements[i + 1];
  
  		/*

  		 * The first element must be a GUID and the second one must be

  		 * a package.
  		 */

  		if (guid->type != ACPI_TYPE_BUFFER ||
  		    guid->buffer.length != 16 ||
  		    links->type != ACPI_TYPE_PACKAGE)

  			break;

  		if (!guid_equal((guid_t *)guid->buffer.pointer, &ads_guid))

  			continue;

  		return acpi_add_nondev_subnodes(scope, links, &data->subnodes,
  						parent);

  	}
  
  	return false;
  }

  
  static bool acpi_property_value_ok(const union acpi_object *value)
  {
  	int j;
  
  	/*
  	 * The value must be an integer, a string, a reference, or a package
  	 * whose every element must be an integer, a string, or a reference.
  	 */
  	switch (value->type) {
  	case ACPI_TYPE_INTEGER:
  	case ACPI_TYPE_STRING:
  	case ACPI_TYPE_LOCAL_REFERENCE:
  		return true;
  
  	case ACPI_TYPE_PACKAGE:
  		for (j = 0; j < value->package.count; j++)
  			switch (value->package.elements[j].type) {
  			case ACPI_TYPE_INTEGER:
  			case ACPI_TYPE_STRING:
  			case ACPI_TYPE_LOCAL_REFERENCE:
  				continue;
  
  			default:
  				return false;
  			}
  
  		return true;
  	}
  	return false;
  }
  
  static bool acpi_properties_format_valid(const union acpi_object *properties)
  {
  	int i;
  
  	for (i = 0; i < properties->package.count; i++) {
  		const union acpi_object *property;
  
  		property = &properties->package.elements[i];
  		/*
  		 * Only two elements allowed, the first one must be a string and
  		 * the second one has to satisfy certain conditions.
  		 */
  		if (property->package.count != 2
  		    || property->package.elements[0].type != ACPI_TYPE_STRING
  		    || !acpi_property_value_ok(&property->package.elements[1]))
  			return false;
  	}
  	return true;
  }

  static void acpi_init_of_compatible(struct acpi_device *adev)
  {
  	const union acpi_object *of_compatible;

  	int ret;

  	ret = acpi_data_get_property_array(&adev->data, "compatible",
  					   ACPI_TYPE_STRING, &of_compatible);

  	if (ret) {
  		ret = acpi_dev_get_property(adev, "compatible",
  					    ACPI_TYPE_STRING, &of_compatible);
  		if (ret) {

  			if (adev->parent
  			    && adev->parent->flags.of_compatible_ok)
  				goto out;

  			return;
  		}
  	}
  	adev->data.of_compatible = of_compatible;

  
   out:
  	adev->flags.of_compatible_ok = 1;

  }

  static bool acpi_is_property_guid(const guid_t *guid)
  {
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(prp_guids); i++) {
  		if (guid_equal(guid, &prp_guids[i]))
  			return true;
  	}
  
  	return false;
  }
  
  struct acpi_device_properties *
  acpi_data_add_props(struct acpi_device_data *data, const guid_t *guid,
  		    const union acpi_object *properties)
  {
  	struct acpi_device_properties *props;
  
  	props = kzalloc(sizeof(*props), GFP_KERNEL);
  	if (props) {
  		INIT_LIST_HEAD(&props->list);
  		props->guid = guid;
  		props->properties = properties;
  		list_add_tail(&props->list, &data->properties);
  	}
  
  	return props;
  }

  static bool acpi_extract_properties(const union acpi_object *desc,
  				    struct acpi_device_data *data)

  {

  	int i;

  	if (desc->package.count % 2)

  		return false;

  	/* Look for the device properties GUID. */

  	for (i = 0; i < desc->package.count; i += 2) {

  		const union acpi_object *guid, *properties;

  		guid = &desc->package.elements[i];

  		properties = &desc->package.elements[i + 1];
  
  		/*

  		 * The first element must be a GUID and the second one must be

  		 * a package.
  		 */

  		if (guid->type != ACPI_TYPE_BUFFER ||
  		    guid->buffer.length != 16 ||
  		    properties->type != ACPI_TYPE_PACKAGE)

  			break;

  		if (!acpi_is_property_guid((guid_t *)guid->buffer.pointer))

  			continue;
  
  		/*

  		 * We found the matching GUID. Now validate the format of the

  		 * package immediately following it.
  		 */
  		if (!acpi_properties_format_valid(properties))

  			continue;

  		acpi_data_add_props(data, (const guid_t *)guid->buffer.pointer,
  				    properties);

  	}

  	return !list_empty(&data->properties);

  }

  void acpi_init_properties(struct acpi_device *adev)
  {
  	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
  	struct acpi_hardware_id *hwid;
  	acpi_status status;
  	bool acpi_of = false;

  	INIT_LIST_HEAD(&adev->data.properties);

  	INIT_LIST_HEAD(&adev->data.subnodes);

  	if (!adev->handle)
  		return;

  	/*
  	 * Check if ACPI_DT_NAMESPACE_HID is present and inthat case we fill in
  	 * Device Tree compatible properties for this device.
  	 */
  	list_for_each_entry(hwid, &adev->pnp.ids, list) {
  		if (!strcmp(hwid->id, ACPI_DT_NAMESPACE_HID)) {
  			acpi_of = true;
  			break;
  		}

  	}

  	status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL, &buf,
  					    ACPI_TYPE_PACKAGE);
  	if (ACPI_FAILURE(status))
  		goto out;
  
  	if (acpi_extract_properties(buf.pointer, &adev->data)) {
  		adev->data.pointer = buf.pointer;
  		if (acpi_of)
  			acpi_init_of_compatible(adev);

  	}

  	if (acpi_enumerate_nondev_subnodes(adev->handle, buf.pointer,
  					&adev->data, acpi_fwnode_handle(adev)))

  		adev->data.pointer = buf.pointer;
  
  	if (!adev->data.pointer) {

  		acpi_handle_debug(adev->handle, "Invalid _DSD data, skipping
  ");
  		ACPI_FREE(buf.pointer);
  	}

  
   out:
  	if (acpi_of && !adev->flags.of_compatible_ok)
  		acpi_handle_info(adev->handle,

  			 ACPI_DT_NAMESPACE_HID " requires 'compatible' property
  ");

  
  	if (!adev->data.pointer)
  		acpi_extract_apple_properties(adev);

  }

  static void acpi_destroy_nondev_subnodes(struct list_head *list)
  {
  	struct acpi_data_node *dn, *next;
  
  	if (list_empty(list))
  		return;
  
  	list_for_each_entry_safe_reverse(dn, next, list, sibling) {
  		acpi_destroy_nondev_subnodes(&dn->data.subnodes);

  		wait_for_completion(&dn->kobj_done);

  		list_del(&dn->sibling);
  		ACPI_FREE((void *)dn->data.pointer);
  		kfree(dn);
  	}
  }

  void acpi_free_properties(struct acpi_device *adev)
  {

  	struct acpi_device_properties *props, *tmp;

  	acpi_destroy_nondev_subnodes(&adev->data.subnodes);

  	ACPI_FREE((void *)adev->data.pointer);

  	adev->data.of_compatible = NULL;

  	adev->data.pointer = NULL;

  	list_for_each_entry_safe(props, tmp, &adev->data.properties, list) {
  		list_del(&props->list);
  		kfree(props);
  	}

  }
  
  /**

   * acpi_data_get_property - return an ACPI property with given name
   * @data: ACPI device deta object to get the property from

   * @name: Name of the property
   * @type: Expected property type
   * @obj: Location to store the property value (if not %NULL)
   *
   * Look up a property with @name and store a pointer to the resulting ACPI
   * object at the location pointed to by @obj if found.
   *
   * Callers must not attempt to free the returned objects.  These objects will be

   * freed by the ACPI core automatically during the removal of @data.

   *
   * Return: %0 if property with @name has been found (success),
   *         %-EINVAL if the arguments are invalid,

   *         %-EINVAL if the property doesn't exist,

   *         %-EPROTO if the property value type doesn't match @type.
   */

  static int acpi_data_get_property(const struct acpi_device_data *data,

  				  const char *name, acpi_object_type type,
  				  const union acpi_object **obj)

  {

  	const struct acpi_device_properties *props;

  	if (!data || !name)

  		return -EINVAL;

  	if (!data->pointer || list_empty(&data->properties))

  		return -EINVAL;

  	list_for_each_entry(props, &data->properties, list) {
  		const union acpi_object *properties;
  		unsigned int i;

  		properties = props->properties;
  		for (i = 0; i < properties->package.count; i++) {
  			const union acpi_object *propname, *propvalue;
  			const union acpi_object *property;
  
  			property = &properties->package.elements[i];

  			propname = &property->package.elements[0];
  			propvalue = &property->package.elements[1];

  			if (!strcmp(name, propname->string.pointer)) {
  				if (type != ACPI_TYPE_ANY &&
  				    propvalue->type != type)
  					return -EPROTO;
  				if (obj)
  					*obj = propvalue;

  				return 0;
  			}

  		}
  	}

  	return -EINVAL;

  }

  
  /**
   * acpi_dev_get_property - return an ACPI property with given name.
   * @adev: ACPI device to get the property from.
   * @name: Name of the property.
   * @type: Expected property type.
   * @obj: Location to store the property value (if not %NULL).
   */

  int acpi_dev_get_property(const struct acpi_device *adev, const char *name,

  			  acpi_object_type type, const union acpi_object **obj)
  {
  	return adev ? acpi_data_get_property(&adev->data, name, type, obj) : -EINVAL;
  }

  EXPORT_SYMBOL_GPL(acpi_dev_get_property);

  static const struct acpi_device_data *
  acpi_device_data_of_node(const struct fwnode_handle *fwnode)

  {

  	if (is_acpi_device_node(fwnode)) {

  		const struct acpi_device *adev = to_acpi_device_node(fwnode);

  		return &adev->data;

  	} else if (is_acpi_data_node(fwnode)) {

  		const struct acpi_data_node *dn = to_acpi_data_node(fwnode);

  		return &dn->data;
  	}
  	return NULL;
  }

  /**

   * acpi_node_prop_get - return an ACPI property with given name.
   * @fwnode: Firmware node to get the property from.
   * @propname: Name of the property.
   * @valptr: Location to store a pointer to the property value (if not %NULL).
   */

  int acpi_node_prop_get(const struct fwnode_handle *fwnode,
  		       const char *propname, void **valptr)

  {
  	return acpi_data_get_property(acpi_device_data_of_node(fwnode),
  				      propname, ACPI_TYPE_ANY,
  				      (const union acpi_object **)valptr);
  }
  
  /**
   * acpi_data_get_property_array - return an ACPI array property with given name
   * @adev: ACPI data object to get the property from

   * @name: Name of the property
   * @type: Expected type of array elements
   * @obj: Location to store a pointer to the property value (if not NULL)
   *
   * Look up an array property with @name and store a pointer to the resulting
   * ACPI object at the location pointed to by @obj if found.
   *
   * Callers must not attempt to free the returned objects.  Those objects will be

   * freed by the ACPI core automatically during the removal of @data.

   *
   * Return: %0 if array property (package) with @name has been found (success),
   *         %-EINVAL if the arguments are invalid,

   *         %-EINVAL if the property doesn't exist,

   *         %-EPROTO if the property is not a package or the type of its elements
   *           doesn't match @type.
   */

  static int acpi_data_get_property_array(const struct acpi_device_data *data,

  					const char *name,
  					acpi_object_type type,
  					const union acpi_object **obj)

  {
  	const union acpi_object *prop;
  	int ret, i;

  	ret = acpi_data_get_property(data, name, ACPI_TYPE_PACKAGE, &prop);

  	if (ret)
  		return ret;
  
  	if (type != ACPI_TYPE_ANY) {
  		/* Check that all elements are of correct type. */
  		for (i = 0; i < prop->package.count; i++)
  			if (prop->package.elements[i].type != type)
  				return -EPROTO;
  	}
  	if (obj)
  		*obj = prop;
  
  	return 0;
  }

  static struct fwnode_handle *
  acpi_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
  				 const char *childname)
  {
  	struct fwnode_handle *child;

  
  	fwnode_for_each_child_node(fwnode, child) {
  		if (is_acpi_data_node(child)) {
  			if (acpi_data_node_match(child, childname))
  				return child;
  			continue;
  		}

  		if (!strncmp(acpi_device_bid(to_acpi_device_node(child)),
  			     childname, ACPI_NAMESEG_SIZE))

  			return child;

  	}

  
  	return NULL;
  }

  /**

   * __acpi_node_get_property_reference - returns handle to the referenced object
   * @fwnode: Firmware node to get the property from

   * @propname: Name of the property

   * @index: Index of the reference to return

   * @num_args: Maximum number of arguments after each reference

   * @args: Location to store the returned reference with optional arguments
   *
   * Find property with @name, verifify that it is a package containing at least
   * one object reference and if so, store the ACPI device object pointer to the

   * target object in @args->adev.  If the reference includes arguments, store
   * them in the @args->args[] array.

   *

   * If there's more than one reference in the property value package, @index is
   * used to select the one to return.

   *

   * It is possible to leave holes in the property value set like in the
   * example below:
   *
   * Package () {
   *     "cs-gpios",
   *     Package () {
   *        ^GPIO, 19, 0, 0,
   *        ^GPIO, 20, 0, 0,
   *        0,
   *        ^GPIO, 21, 0, 0,
   *     }
   * }
   *

   * Calling this function with index %2 or index %3 return %-ENOENT. If the
   * property does not contain any more values %-ENOENT is returned. The NULL
   * entry must be single integer and preferably contain value %0.

   *

   * Return: %0 on success, negative error code on failure.
   */

  int __acpi_node_get_property_reference(const struct fwnode_handle *fwnode,

  	const char *propname, size_t index, size_t num_args,

  	struct fwnode_reference_args *args)

  {
  	const union acpi_object *element, *end;
  	const union acpi_object *obj;

  	const struct acpi_device_data *data;

  	struct acpi_device *device;
  	int ret, idx = 0;

  	data = acpi_device_data_of_node(fwnode);
  	if (!data)

  		return -ENOENT;

  	ret = acpi_data_get_property(data, propname, ACPI_TYPE_ANY, &obj);

  	if (ret)

  		return ret == -EINVAL ? -ENOENT : -EINVAL;

  
  	/*
  	 * The simplest case is when the value is a single reference.  Just
  	 * return that reference then.
  	 */
  	if (obj->type == ACPI_TYPE_LOCAL_REFERENCE) {

  		if (index)

  			return -EINVAL;
  
  		ret = acpi_bus_get_device(obj->reference.handle, &device);
  		if (ret)

  			return ret == -ENODEV ? -EINVAL : ret;

  		args->fwnode = acpi_fwnode_handle(device);

  		args->nargs = 0;
  		return 0;
  	}
  
  	/*
  	 * If it is not a single reference, then it is a package of
  	 * references followed by number of ints as follows:
  	 *
  	 *  Package () { REF, INT, REF, INT, INT }
  	 *
  	 * The index argument is then used to determine which reference
  	 * the caller wants (along with the arguments).
  	 */

  	if (obj->type != ACPI_TYPE_PACKAGE)
  		return -EINVAL;
  	if (index >= obj->package.count)
  		return -ENOENT;

  
  	element = obj->package.elements;
  	end = element + obj->package.count;
  
  	while (element < end) {
  		u32 nargs, i;

  		if (element->type == ACPI_TYPE_LOCAL_REFERENCE) {

  			struct fwnode_handle *ref_fwnode;

  			ret = acpi_bus_get_device(element->reference.handle,
  						  &device);
  			if (ret)

  				return -EINVAL;

  
  			nargs = 0;
  			element++;

  			/*
  			 * Find the referred data extension node under the
  			 * referred device node.
  			 */
  			for (ref_fwnode = acpi_fwnode_handle(device);
  			     element < end && element->type == ACPI_TYPE_STRING;
  			     element++) {
  				ref_fwnode = acpi_fwnode_get_named_child_node(
  					ref_fwnode, element->string.pointer);
  				if (!ref_fwnode)
  					return -EINVAL;
  			}

  			/* assume following integer elements are all args */
  			for (i = 0; element + i < end && i < num_args; i++) {
  				int type = element[i].type;
  
  				if (type == ACPI_TYPE_INTEGER)
  					nargs++;
  				else if (type == ACPI_TYPE_LOCAL_REFERENCE)
  					break;
  				else

  					return -EINVAL;

  			}

  			if (nargs > NR_FWNODE_REFERENCE_ARGS)

  				return -EINVAL;

  			if (idx == index) {

  				args->fwnode = ref_fwnode;

  				args->nargs = nargs;
  				for (i = 0; i < nargs; i++)
  					args->args[i] = element[i].integer.value;

  				return 0;
  			}
  
  			element += nargs;
  		} else if (element->type == ACPI_TYPE_INTEGER) {
  			if (idx == index)
  				return -ENOENT;
  			element++;
  		} else {

  			return -EINVAL;

  		}

  		idx++;

  	}

  	return -ENOENT;

  }

  EXPORT_SYMBOL_GPL(__acpi_node_get_property_reference);

  static int acpi_data_prop_read_single(const struct acpi_device_data *data,

  				      const char *propname,
  				      enum dev_prop_type proptype, void *val)

  {
  	const union acpi_object *obj;
  	int ret;
  
  	if (!val)
  		return -EINVAL;
  
  	if (proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64) {

  		ret = acpi_data_get_property(data, propname, ACPI_TYPE_INTEGER, &obj);

  		if (ret)
  			return ret;
  
  		switch (proptype) {
  		case DEV_PROP_U8:
  			if (obj->integer.value > U8_MAX)
  				return -EOVERFLOW;
  			*(u8 *)val = obj->integer.value;
  			break;
  		case DEV_PROP_U16:
  			if (obj->integer.value > U16_MAX)
  				return -EOVERFLOW;
  			*(u16 *)val = obj->integer.value;
  			break;
  		case DEV_PROP_U32:
  			if (obj->integer.value > U32_MAX)
  				return -EOVERFLOW;
  			*(u32 *)val = obj->integer.value;
  			break;
  		default:
  			*(u64 *)val = obj->integer.value;
  			break;
  		}
  	} else if (proptype == DEV_PROP_STRING) {

  		ret = acpi_data_get_property(data, propname, ACPI_TYPE_STRING, &obj);

  		if (ret)
  			return ret;
  
  		*(char **)val = obj->string.pointer;

  
  		return 1;

  	} else {
  		ret = -EINVAL;
  	}
  	return ret;
  }

  int acpi_dev_prop_read_single(struct acpi_device *adev, const char *propname,
  			      enum dev_prop_type proptype, void *val)
  {

  	int ret;
  
  	if (!adev)
  		return -EINVAL;
  
  	ret = acpi_data_prop_read_single(&adev->data, propname, proptype, val);
  	if (ret < 0 || proptype != ACPI_TYPE_STRING)
  		return ret;
  	return 0;

  }

  static int acpi_copy_property_array_u8(const union acpi_object *items, u8 *val,
  				       size_t nval)
  {
  	int i;
  
  	for (i = 0; i < nval; i++) {
  		if (items[i].type != ACPI_TYPE_INTEGER)
  			return -EPROTO;
  		if (items[i].integer.value > U8_MAX)
  			return -EOVERFLOW;
  
  		val[i] = items[i].integer.value;
  	}
  	return 0;
  }
  
  static int acpi_copy_property_array_u16(const union acpi_object *items,
  					u16 *val, size_t nval)
  {
  	int i;
  
  	for (i = 0; i < nval; i++) {
  		if (items[i].type != ACPI_TYPE_INTEGER)
  			return -EPROTO;
  		if (items[i].integer.value > U16_MAX)
  			return -EOVERFLOW;
  
  		val[i] = items[i].integer.value;
  	}
  	return 0;
  }
  
  static int acpi_copy_property_array_u32(const union acpi_object *items,
  					u32 *val, size_t nval)
  {
  	int i;
  
  	for (i = 0; i < nval; i++) {
  		if (items[i].type != ACPI_TYPE_INTEGER)
  			return -EPROTO;
  		if (items[i].integer.value > U32_MAX)
  			return -EOVERFLOW;
  
  		val[i] = items[i].integer.value;
  	}
  	return 0;
  }
  
  static int acpi_copy_property_array_u64(const union acpi_object *items,
  					u64 *val, size_t nval)
  {
  	int i;
  
  	for (i = 0; i < nval; i++) {
  		if (items[i].type != ACPI_TYPE_INTEGER)
  			return -EPROTO;
  
  		val[i] = items[i].integer.value;
  	}
  	return 0;
  }
  
  static int acpi_copy_property_array_string(const union acpi_object *items,
  					   char **val, size_t nval)
  {
  	int i;
  
  	for (i = 0; i < nval; i++) {
  		if (items[i].type != ACPI_TYPE_STRING)
  			return -EPROTO;
  
  		val[i] = items[i].string.pointer;
  	}

  	return nval;

  }

  static int acpi_data_prop_read(const struct acpi_device_data *data,

  			       const char *propname,
  			       enum dev_prop_type proptype,
  			       void *val, size_t nval)

  {
  	const union acpi_object *obj;
  	const union acpi_object *items;
  	int ret;
  
  	if (val && nval == 1) {

  		ret = acpi_data_prop_read_single(data, propname, proptype, val);

  		if (ret >= 0)

  			return ret;
  	}

  	ret = acpi_data_get_property_array(data, propname, ACPI_TYPE_ANY, &obj);

  	if (ret)
  		return ret;
  
  	if (!val)
  		return obj->package.count;

  	if (proptype != DEV_PROP_STRING && nval > obj->package.count)

  		return -EOVERFLOW;

  	else if (nval <= 0)
  		return -EINVAL;

  
  	items = obj->package.elements;

  	switch (proptype) {
  	case DEV_PROP_U8:
  		ret = acpi_copy_property_array_u8(items, (u8 *)val, nval);
  		break;
  	case DEV_PROP_U16:
  		ret = acpi_copy_property_array_u16(items, (u16 *)val, nval);
  		break;
  	case DEV_PROP_U32:
  		ret = acpi_copy_property_array_u32(items, (u32 *)val, nval);
  		break;
  	case DEV_PROP_U64:
  		ret = acpi_copy_property_array_u64(items, (u64 *)val, nval);
  		break;
  	case DEV_PROP_STRING:

  		ret = acpi_copy_property_array_string(
  			items, (char **)val,
  			min_t(u32, nval, obj->package.count));

  		break;
  	default:
  		ret = -EINVAL;
  		break;
  	}
  	return ret;
  }

  int acpi_dev_prop_read(const struct acpi_device *adev, const char *propname,

  		       enum dev_prop_type proptype, void *val, size_t nval)
  {
  	return adev ? acpi_data_prop_read(&adev->data, propname, proptype, val, nval) : -EINVAL;
  }
  
  /**
   * acpi_node_prop_read - retrieve the value of an ACPI property with given name.
   * @fwnode: Firmware node to get the property from.
   * @propname: Name of the property.
   * @proptype: Expected property type.
   * @val: Location to store the property value (if not %NULL).
   * @nval: Size of the array pointed to by @val.
   *
   * If @val is %NULL, return the number of array elements comprising the value
   * of the property.  Otherwise, read at most @nval values to the array at the
   * location pointed to by @val.
   */

  int acpi_node_prop_read(const struct fwnode_handle *fwnode,
  			const char *propname, enum dev_prop_type proptype,
  			void *val, size_t nval)

  {
  	return acpi_data_prop_read(acpi_device_data_of_node(fwnode),
  				   propname, proptype, val, nval);
  }

  
  /**

   * acpi_get_next_subnode - Return the next child node handle for a fwnode
   * @fwnode: Firmware node to find the next child node for.

   * @child: Handle to one of the device's child nodes or a null handle.
   */

  struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode,

  					    struct fwnode_handle *child)
  {

  	const struct acpi_device *adev = to_acpi_device_node(fwnode);

  	const struct list_head *head;
  	struct list_head *next;

  	if (!child || is_acpi_device_node(child)) {

  		struct acpi_device *child_adev;

  		if (adev)
  			head = &adev->children;
  		else
  			goto nondev;

  		if (list_empty(head))
  			goto nondev;
  
  		if (child) {

  			adev = to_acpi_device_node(child);
  			next = adev->node.next;

  			if (next == head) {
  				child = NULL;
  				goto nondev;
  			}

  			child_adev = list_entry(next, struct acpi_device, node);

  		} else {

  			child_adev = list_first_entry(head, struct acpi_device,
  						      node);

  		}

  		return acpi_fwnode_handle(child_adev);

  	}
  
   nondev:

  	if (!child || is_acpi_data_node(child)) {

  		const struct acpi_data_node *data = to_acpi_data_node(fwnode);

  		struct acpi_data_node *dn;

  		/*
  		 * We can have a combination of device and data nodes, e.g. with
  		 * hierarchical _DSD properties. Make sure the adev pointer is
  		 * restored before going through data nodes, otherwise we will
  		 * be looking for data_nodes below the last device found instead
  		 * of the common fwnode shared by device_nodes and data_nodes.
  		 */
  		adev = to_acpi_device_node(fwnode);

  		if (adev)
  			head = &adev->data.subnodes;

  		else if (data)
  			head = &data->data.subnodes;
  		else
  			return NULL;

  		if (list_empty(head))
  			return NULL;
  
  		if (child) {
  			dn = to_acpi_data_node(child);
  			next = dn->sibling.next;
  			if (next == head)
  				return NULL;
  
  			dn = list_entry(next, struct acpi_data_node, sibling);
  		} else {
  			dn = list_first_entry(head, struct acpi_data_node, sibling);
  		}
  		return &dn->fwnode;
  	}
  	return NULL;
  }

  
  /**
   * acpi_node_get_parent - Return parent fwnode of this fwnode
   * @fwnode: Firmware node whose parent to get
   *
   * Returns parent node of an ACPI device or data firmware node or %NULL if
   * not available.
   */

  struct fwnode_handle *acpi_node_get_parent(const struct fwnode_handle *fwnode)

  {
  	if (is_acpi_data_node(fwnode)) {
  		/* All data nodes have parent pointer so just return that */
  		return to_acpi_data_node(fwnode)->parent;
  	} else if (is_acpi_device_node(fwnode)) {
  		acpi_handle handle, parent_handle;
  
  		handle = to_acpi_device_node(fwnode)->handle;
  		if (ACPI_SUCCESS(acpi_get_parent(handle, &parent_handle))) {
  			struct acpi_device *adev;
  
  			if (!acpi_bus_get_device(parent_handle, &adev))
  				return acpi_fwnode_handle(adev);
  		}
  	}
  
  	return NULL;
  }

  /*
   * Return true if the node is an ACPI graph node. Called on either ports
   * or endpoints.
   */
  static bool is_acpi_graph_node(struct fwnode_handle *fwnode,
  			       const char *str)
  {
  	unsigned int len = strlen(str);
  	const char *name;
  
  	if (!len || !is_acpi_data_node(fwnode))
  		return false;
  
  	name = to_acpi_data_node(fwnode)->name;
  
  	return (fwnode_property_present(fwnode, "reg") &&
  		!strncmp(name, str, len) && name[len] == '@') ||
  		fwnode_property_present(fwnode, str);
  }

  /**
   * acpi_graph_get_next_endpoint - Get next endpoint ACPI firmware node
   * @fwnode: Pointer to the parent firmware node
   * @prev: Previous endpoint node or %NULL to get the first
   *
   * Looks up next endpoint ACPI firmware node below a given @fwnode. Returns

   * %NULL if there is no next endpoint or in case of error. In case of success
   * the next endpoint is returned.

   */

  static struct fwnode_handle *acpi_graph_get_next_endpoint(

  	const struct fwnode_handle *fwnode, struct fwnode_handle *prev)

  {
  	struct fwnode_handle *port = NULL;
  	struct fwnode_handle *endpoint;
  
  	if (!prev) {
  		do {
  			port = fwnode_get_next_child_node(fwnode, port);

  			/*
  			 * The names of the port nodes begin with "port@"
  			 * followed by the number of the port node and they also
  			 * have a "reg" property that also has the number of the
  			 * port node. For compatibility reasons a node is also
  			 * recognised as a port node from the "port" property.
  			 */
  			if (is_acpi_graph_node(port, "port"))

  				break;
  		} while (port);
  	} else {
  		port = fwnode_get_parent(prev);
  	}
  
  	if (!port)
  		return NULL;
  
  	endpoint = fwnode_get_next_child_node(port, prev);
  	while (!endpoint) {
  		port = fwnode_get_next_child_node(fwnode, port);
  		if (!port)
  			break;

  		if (is_acpi_graph_node(port, "port"))

  			endpoint = fwnode_get_next_child_node(port, NULL);
  	}

  	/*
  	 * The names of the endpoint nodes begin with "endpoint@" followed by
  	 * the number of the endpoint node and they also have a "reg" property
  	 * that also has the number of the endpoint node. For compatibility
  	 * reasons a node is also recognised as an endpoint node from the
  	 * "endpoint" property.
  	 */
  	if (!is_acpi_graph_node(endpoint, "endpoint"))

  		return NULL;

  
  	return endpoint;
  }
  
  /**
   * acpi_graph_get_child_prop_value - Return a child with a given property value
   * @fwnode: device fwnode
   * @prop_name: The name of the property to look for
   * @val: the desired property value
   *
   * Return the port node corresponding to a given port number. Returns
   * the child node on success, NULL otherwise.
   */
  static struct fwnode_handle *acpi_graph_get_child_prop_value(

  	const struct fwnode_handle *fwnode, const char *prop_name,
  	unsigned int val)

  {
  	struct fwnode_handle *child;
  
  	fwnode_for_each_child_node(fwnode, child) {
  		u32 nr;

  		if (fwnode_property_read_u32(child, prop_name, &nr))

  			continue;
  
  		if (val == nr)
  			return child;
  	}
  
  	return NULL;
  }
  
  
  /**

   * acpi_graph_get_remote_endpoint - Parses and returns remote end of an endpoint

   * @fwnode: Endpoint firmware node pointing to a remote device

   * @endpoint: Firmware node of remote endpoint is filled here if not %NULL
   *

   * Returns the remote endpoint corresponding to @__fwnode. NULL on error.

   */

  static struct fwnode_handle *
  acpi_graph_get_remote_endpoint(const struct fwnode_handle *__fwnode)

  {

  	struct fwnode_handle *fwnode;

  	unsigned int port_nr, endpoint_nr;

  	struct fwnode_reference_args args;

  	int ret;
  
  	memset(&args, 0, sizeof(args));

  	ret = acpi_node_get_property_reference(__fwnode, "remote-endpoint", 0,

  					       &args);
  	if (ret)

  		return NULL;

  	/* Direct endpoint reference? */

  	if (!is_acpi_device_node(args.fwnode))

  		return args.nargs ? NULL : args.fwnode;

  	/*
  	 * Always require two arguments with the reference: port and
  	 * endpoint indices.
  	 */
  	if (args.nargs != 2)

  		return NULL;

  	fwnode = args.fwnode;

  	port_nr = args.args[0];
  	endpoint_nr = args.args[1];

  	fwnode = acpi_graph_get_child_prop_value(fwnode, "port", port_nr);

  	return acpi_graph_get_child_prop_value(fwnode, "endpoint", endpoint_nr);

  }

  static bool acpi_fwnode_device_is_available(const struct fwnode_handle *fwnode)

  {
  	if (!is_acpi_device_node(fwnode))
  		return false;
  
  	return acpi_device_is_present(to_acpi_device_node(fwnode));
  }

  static bool acpi_fwnode_property_present(const struct fwnode_handle *fwnode,

  					 const char *propname)
  {
  	return !acpi_node_prop_get(fwnode, propname, NULL);
  }

  static int
  acpi_fwnode_property_read_int_array(const struct fwnode_handle *fwnode,
  				    const char *propname,
  				    unsigned int elem_size, void *val,
  				    size_t nval)

  {
  	enum dev_prop_type type;
  
  	switch (elem_size) {
  	case sizeof(u8):
  		type = DEV_PROP_U8;
  		break;
  	case sizeof(u16):
  		type = DEV_PROP_U16;
  		break;
  	case sizeof(u32):
  		type = DEV_PROP_U32;
  		break;
  	case sizeof(u64):
  		type = DEV_PROP_U64;
  		break;
  	default:
  		return -ENXIO;
  	}
  
  	return acpi_node_prop_read(fwnode, propname, type, val, nval);
  }

  static int
  acpi_fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
  				       const char *propname, const char **val,
  				       size_t nval)

  {
  	return acpi_node_prop_read(fwnode, propname, DEV_PROP_STRING,
  				   val, nval);
  }

  static int
  acpi_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
  			       const char *prop, const char *nargs_prop,
  			       unsigned int args_count, unsigned int index,
  			       struct fwnode_reference_args *args)
  {

  	return __acpi_node_get_property_reference(fwnode, prop, index,
  						  args_count, args);

  }

  static const char *acpi_fwnode_get_name(const struct fwnode_handle *fwnode)
  {
  	const struct acpi_device *adev;
  	struct fwnode_handle *parent;
  
  	/* Is this the root node? */
  	parent = fwnode_get_parent(fwnode);
  	if (!parent)
  		return "\\";
  
  	fwnode_handle_put(parent);
  
  	if (is_acpi_data_node(fwnode)) {
  		const struct acpi_data_node *dn = to_acpi_data_node(fwnode);
  
  		return dn->name;
  	}
  
  	adev = to_acpi_device_node(fwnode);
  	if (WARN_ON(!adev))
  		return NULL;
  
  	return acpi_device_bid(adev);
  }

  static const char *
  acpi_fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
  {
  	struct fwnode_handle *parent;
  
  	/* Is this the root node? */
  	parent = fwnode_get_parent(fwnode);
  	if (!parent)
  		return "";
  
  	/* Is this 2nd node from the root? */
  	parent = fwnode_get_next_parent(parent);
  	if (!parent)
  		return "";
  
  	fwnode_handle_put(parent);
  
  	/* ACPI device or data node. */
  	return ".";
  }

  static struct fwnode_handle *

  acpi_fwnode_get_parent(struct fwnode_handle *fwnode)
  {
  	return acpi_node_get_parent(fwnode);
  }
  
  static int acpi_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,

  					    struct fwnode_endpoint *endpoint)
  {
  	struct fwnode_handle *port_fwnode = fwnode_get_parent(fwnode);
  
  	endpoint->local_fwnode = fwnode;

  	if (fwnode_property_read_u32(port_fwnode, "reg", &endpoint->port))
  		fwnode_property_read_u32(port_fwnode, "port", &endpoint->port);
  	if (fwnode_property_read_u32(fwnode, "reg", &endpoint->id))
  		fwnode_property_read_u32(fwnode, "endpoint", &endpoint->id);

  
  	return 0;
  }

  static const void *

  acpi_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
  				  const struct device *dev)
  {

  	return acpi_device_get_match_data(dev);

  }

  #define DECLARE_ACPI_FWNODE_OPS(ops) \
  	const struct fwnode_operations ops = {				\
  		.device_is_available = acpi_fwnode_device_is_available, \

  		.device_get_match_data = acpi_fwnode_device_get_match_data, \

  		.property_present = acpi_fwnode_property_present,	\
  		.property_read_int_array =				\
  			acpi_fwnode_property_read_int_array,		\
  		.property_read_string_array =				\
  			acpi_fwnode_property_read_string_array,		\
  		.get_parent = acpi_node_get_parent,			\
  		.get_next_child_node = acpi_get_next_subnode,		\
  		.get_named_child_node = acpi_fwnode_get_named_child_node, \

  		.get_name = acpi_fwnode_get_name,			\

  		.get_name_prefix = acpi_fwnode_get_name_prefix,		\

  		.get_reference_args = acpi_fwnode_get_reference_args,	\

  		.graph_get_next_endpoint =				\

  			acpi_graph_get_next_endpoint,			\

  		.graph_get_remote_endpoint =				\

  			acpi_graph_get_remote_endpoint,			\

  		.graph_get_port_parent = acpi_fwnode_get_parent,	\

  		.graph_parse_endpoint = acpi_fwnode_graph_parse_endpoint, \
  	};								\
  	EXPORT_SYMBOL_GPL(ops)
  
  DECLARE_ACPI_FWNODE_OPS(acpi_device_fwnode_ops);
  DECLARE_ACPI_FWNODE_OPS(acpi_data_fwnode_ops);
  const struct fwnode_operations acpi_static_fwnode_ops;

  
  bool is_acpi_device_node(const struct fwnode_handle *fwnode)
  {
  	return !IS_ERR_OR_NULL(fwnode) &&
  		fwnode->ops == &acpi_device_fwnode_ops;
  }
  EXPORT_SYMBOL(is_acpi_device_node);
  
  bool is_acpi_data_node(const struct fwnode_handle *fwnode)
  {
  	return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &acpi_data_fwnode_ops;
  }
  EXPORT_SYMBOL(is_acpi_data_node);