/*
   * property.c - Unified device property interface.
   *
   * Copyright (C) 2014, Intel Corporation
   * Authors: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   *          Mika Westerberg <mika.westerberg@linux.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/export.h>
  #include <linux/kernel.h>

  #include <linux/of.h>

  #include <linux/of_address.h>

  #include <linux/property.h>

  #include <linux/etherdevice.h>
  #include <linux/phy.h>

  struct property_set {
  	struct fwnode_handle fwnode;
  	struct property_entry *properties;
  };

  static inline bool is_pset_node(struct fwnode_handle *fwnode)

  {

  	return !IS_ERR_OR_NULL(fwnode) && fwnode->type == FWNODE_PDATA;

  }

  static inline struct property_set *to_pset_node(struct fwnode_handle *fwnode)

  {

  	return is_pset_node(fwnode) ?

  		container_of(fwnode, struct property_set, fwnode) : NULL;
  }
  
  static struct property_entry *pset_prop_get(struct property_set *pset,
  					    const char *name)
  {
  	struct property_entry *prop;
  
  	if (!pset || !pset->properties)
  		return NULL;
  
  	for (prop = pset->properties; prop->name; prop++)
  		if (!strcmp(name, prop->name))
  			return prop;
  
  	return NULL;
  }

  static void *pset_prop_find(struct property_set *pset, const char *propname,
  			    size_t length)

  {
  	struct property_entry *prop;

  	void *pointer;

  	prop = pset_prop_get(pset, propname);
  	if (!prop)
  		return ERR_PTR(-EINVAL);

  	if (prop->is_array)
  		pointer = prop->pointer.raw_data;
  	else
  		pointer = &prop->value.raw_data;

  	if (!pointer)
  		return ERR_PTR(-ENODATA);
  	if (length > prop->length)
  		return ERR_PTR(-EOVERFLOW);
  	return pointer;
  }
  
  static int pset_prop_read_u8_array(struct property_set *pset,
  				   const char *propname,
  				   u8 *values, size_t nval)
  {
  	void *pointer;
  	size_t length = nval * sizeof(*values);
  
  	pointer = pset_prop_find(pset, propname, length);
  	if (IS_ERR(pointer))
  		return PTR_ERR(pointer);
  
  	memcpy(values, pointer, length);
  	return 0;
  }
  
  static int pset_prop_read_u16_array(struct property_set *pset,
  				    const char *propname,
  				    u16 *values, size_t nval)
  {
  	void *pointer;
  	size_t length = nval * sizeof(*values);
  
  	pointer = pset_prop_find(pset, propname, length);
  	if (IS_ERR(pointer))
  		return PTR_ERR(pointer);
  
  	memcpy(values, pointer, length);
  	return 0;
  }
  
  static int pset_prop_read_u32_array(struct property_set *pset,
  				    const char *propname,
  				    u32 *values, size_t nval)
  {
  	void *pointer;
  	size_t length = nval * sizeof(*values);
  
  	pointer = pset_prop_find(pset, propname, length);
  	if (IS_ERR(pointer))
  		return PTR_ERR(pointer);
  
  	memcpy(values, pointer, length);
  	return 0;
  }
  
  static int pset_prop_read_u64_array(struct property_set *pset,
  				    const char *propname,
  				    u64 *values, size_t nval)
  {
  	void *pointer;
  	size_t length = nval * sizeof(*values);
  
  	pointer = pset_prop_find(pset, propname, length);
  	if (IS_ERR(pointer))
  		return PTR_ERR(pointer);
  
  	memcpy(values, pointer, length);
  	return 0;
  }
  
  static int pset_prop_count_elems_of_size(struct property_set *pset,
  					 const char *propname, size_t length)
  {
  	struct property_entry *prop;
  
  	prop = pset_prop_get(pset, propname);

  	if (!prop)

  		return -EINVAL;

  
  	return prop->length / length;
  }
  
  static int pset_prop_read_string_array(struct property_set *pset,
  				       const char *propname,
  				       const char **strings, size_t nval)
  {
  	void *pointer;
  	size_t length = nval * sizeof(*strings);
  
  	pointer = pset_prop_find(pset, propname, length);
  	if (IS_ERR(pointer))
  		return PTR_ERR(pointer);
  
  	memcpy(strings, pointer, length);

  	return 0;
  }

  static int pset_prop_read_string(struct property_set *pset,
  				 const char *propname, const char **strings)
  {
  	struct property_entry *prop;
  	const char **pointer;
  
  	prop = pset_prop_get(pset, propname);
  	if (!prop)
  		return -EINVAL;
  	if (!prop->is_string)
  		return -EILSEQ;
  	if (prop->is_array) {
  		pointer = prop->pointer.str;
  		if (!pointer)
  			return -ENODATA;
  	} else {
  		pointer = &prop->value.str;
  		if (*pointer && strnlen(*pointer, prop->length) >= prop->length)
  			return -EILSEQ;
  	}
  
  	*strings = *pointer;
  	return 0;
  }

  static inline struct fwnode_handle *dev_fwnode(struct device *dev)
  {
  	return IS_ENABLED(CONFIG_OF) && dev->of_node ?
  		&dev->of_node->fwnode : dev->fwnode;
  }

  
  /**
   * device_property_present - check if a property of a device is present
   * @dev: Device whose property is being checked
   * @propname: Name of the property
   *
   * Check if property @propname is present in the device firmware description.
   */
  bool device_property_present(struct device *dev, const char *propname)
  {

  	return fwnode_property_present(dev_fwnode(dev), propname);

  }
  EXPORT_SYMBOL_GPL(device_property_present);

  static bool __fwnode_property_present(struct fwnode_handle *fwnode,
  				      const char *propname)

  {
  	if (is_of_node(fwnode))

  		return of_property_read_bool(to_of_node(fwnode), propname);

  	else if (is_acpi_node(fwnode))

  		return !acpi_node_prop_get(fwnode, propname, NULL);

  	else if (is_pset_node(fwnode))
  		return !!pset_prop_get(to_pset_node(fwnode), propname);

  	return false;

  }

  
  /**
   * fwnode_property_present - check if a property of a firmware node is present
   * @fwnode: Firmware node whose property to check
   * @propname: Name of the property
   */
  bool fwnode_property_present(struct fwnode_handle *fwnode, const char *propname)
  {
  	bool ret;
  
  	ret = __fwnode_property_present(fwnode, propname);

  	if (ret == false && !IS_ERR_OR_NULL(fwnode) &&
  	    !IS_ERR_OR_NULL(fwnode->secondary))

  		ret = __fwnode_property_present(fwnode->secondary, propname);
  	return ret;
  }

  EXPORT_SYMBOL_GPL(fwnode_property_present);

  /**
   * device_property_read_u8_array - return a u8 array property of a device
   * @dev: Device to get the property of
   * @propname: Name of the property

   * @val: The values are stored here or %NULL to return the number of values

   * @nval: Size of the @val array
   *
   * Function reads an array of u8 properties with @propname from the device
   * firmware description and stores them to @val if found.
   *

   * Return: number of values if @val was %NULL,
   *         %0 if the property was found (success),

   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO if the property is not an array of numbers,
   *	   %-EOVERFLOW if the size of the property is not as expected.

   *	   %-ENXIO if no suitable firmware interface is present.

   */
  int device_property_read_u8_array(struct device *dev, const char *propname,
  				  u8 *val, size_t nval)
  {

  	return fwnode_property_read_u8_array(dev_fwnode(dev), propname, val, nval);

  }
  EXPORT_SYMBOL_GPL(device_property_read_u8_array);
  
  /**
   * device_property_read_u16_array - return a u16 array property of a device
   * @dev: Device to get the property of
   * @propname: Name of the property

   * @val: The values are stored here or %NULL to return the number of values

   * @nval: Size of the @val array
   *
   * Function reads an array of u16 properties with @propname from the device
   * firmware description and stores them to @val if found.
   *

   * Return: number of values if @val was %NULL,
   *         %0 if the property was found (success),

   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO if the property is not an array of numbers,
   *	   %-EOVERFLOW if the size of the property is not as expected.

   *	   %-ENXIO if no suitable firmware interface is present.

   */
  int device_property_read_u16_array(struct device *dev, const char *propname,
  				   u16 *val, size_t nval)
  {

  	return fwnode_property_read_u16_array(dev_fwnode(dev), propname, val, nval);

  }
  EXPORT_SYMBOL_GPL(device_property_read_u16_array);
  
  /**
   * device_property_read_u32_array - return a u32 array property of a device
   * @dev: Device to get the property of
   * @propname: Name of the property

   * @val: The values are stored here or %NULL to return the number of values

   * @nval: Size of the @val array
   *
   * Function reads an array of u32 properties with @propname from the device
   * firmware description and stores them to @val if found.
   *

   * Return: number of values if @val was %NULL,
   *         %0 if the property was found (success),

   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO if the property is not an array of numbers,
   *	   %-EOVERFLOW if the size of the property is not as expected.

   *	   %-ENXIO if no suitable firmware interface is present.

   */
  int device_property_read_u32_array(struct device *dev, const char *propname,
  				   u32 *val, size_t nval)
  {

  	return fwnode_property_read_u32_array(dev_fwnode(dev), propname, val, nval);

  }
  EXPORT_SYMBOL_GPL(device_property_read_u32_array);
  
  /**
   * device_property_read_u64_array - return a u64 array property of a device
   * @dev: Device to get the property of
   * @propname: Name of the property

   * @val: The values are stored here or %NULL to return the number of values

   * @nval: Size of the @val array
   *
   * Function reads an array of u64 properties with @propname from the device
   * firmware description and stores them to @val if found.
   *

   * Return: number of values if @val was %NULL,
   *         %0 if the property was found (success),

   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO if the property is not an array of numbers,
   *	   %-EOVERFLOW if the size of the property is not as expected.

   *	   %-ENXIO if no suitable firmware interface is present.

   */
  int device_property_read_u64_array(struct device *dev, const char *propname,
  				   u64 *val, size_t nval)
  {

  	return fwnode_property_read_u64_array(dev_fwnode(dev), propname, val, nval);

  }
  EXPORT_SYMBOL_GPL(device_property_read_u64_array);
  
  /**
   * device_property_read_string_array - return a string array property of device
   * @dev: Device to get the property of
   * @propname: Name of the property

   * @val: The values are stored here or %NULL to return the number of values

   * @nval: Size of the @val array
   *
   * Function reads an array of string properties with @propname from the device
   * firmware description and stores them to @val if found.
   *

   * Return: number of values if @val was %NULL,
   *         %0 if the property was found (success),

   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO or %-EILSEQ if the property is not an array of strings,
   *	   %-EOVERFLOW if the size of the property is not as expected.

   *	   %-ENXIO if no suitable firmware interface is present.

   */
  int device_property_read_string_array(struct device *dev, const char *propname,
  				      const char **val, size_t nval)
  {

  	return fwnode_property_read_string_array(dev_fwnode(dev), propname, val, nval);

  }
  EXPORT_SYMBOL_GPL(device_property_read_string_array);
  
  /**
   * device_property_read_string - return a string property of a device
   * @dev: Device to get the property of
   * @propname: Name of the property
   * @val: The value is stored here
   *
   * Function reads property @propname from the device firmware description and
   * stores the value into @val if found. The value is checked to be a string.
   *
   * Return: %0 if the property was found (success),
   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO or %-EILSEQ if the property type is not a string.

   *	   %-ENXIO if no suitable firmware interface is present.

   */
  int device_property_read_string(struct device *dev, const char *propname,
  				const char **val)
  {

  	return fwnode_property_read_string(dev_fwnode(dev), propname, val);

  }
  EXPORT_SYMBOL_GPL(device_property_read_string);

  /**
   * device_property_match_string - find a string in an array and return index
   * @dev: Device to get the property of
   * @propname: Name of the property holding the array
   * @string: String to look for
   *
   * Find a given string in a string array and if it is found return the
   * index back.
   *
   * Return: %0 if the property was found (success),
   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO if the property is not an array of strings,
   *	   %-ENXIO if no suitable firmware interface is present.
   */
  int device_property_match_string(struct device *dev, const char *propname,
  				 const char *string)
  {
  	return fwnode_property_match_string(dev_fwnode(dev), propname, string);
  }
  EXPORT_SYMBOL_GPL(device_property_match_string);

  #define OF_DEV_PROP_READ_ARRAY(node, propname, type, val, nval)				\
  	(val) ? of_property_read_##type##_array((node), (propname), (val), (nval))	\

  	      : of_property_count_elems_of_size((node), (propname), sizeof(type))

  #define PSET_PROP_READ_ARRAY(node, propname, type, val, nval)				\
  	(val) ? pset_prop_read_##type##_array((node), (propname), (val), (nval))	\
  	      : pset_prop_count_elems_of_size((node), (propname), sizeof(type))

  #define FWNODE_PROP_READ(_fwnode_, _propname_, _type_, _proptype_, _val_, _nval_)	\

  ({											\
  	int _ret_;									\
  	if (is_of_node(_fwnode_))							\
  		_ret_ = OF_DEV_PROP_READ_ARRAY(to_of_node(_fwnode_), _propname_,	\
  					       _type_, _val_, _nval_);			\
  	else if (is_acpi_node(_fwnode_))						\
  		_ret_ = acpi_node_prop_read(_fwnode_, _propname_, _proptype_,		\
  					    _val_, _nval_);				\

  	else if (is_pset_node(_fwnode_)) 						\

  		_ret_ = PSET_PROP_READ_ARRAY(to_pset_node(_fwnode_), _propname_,	\
  					     _type_, _val_, _nval_);			\

  	else										\
  		_ret_ = -ENXIO;								\
  	_ret_;										\

  })

  #define FWNODE_PROP_READ_ARRAY(_fwnode_, _propname_, _type_, _proptype_, _val_, _nval_)	\
  ({											\
  	int _ret_;									\
  	_ret_ = FWNODE_PROP_READ(_fwnode_, _propname_, _type_, _proptype_,		\
  				 _val_, _nval_);					\

  	if (_ret_ == -EINVAL && !IS_ERR_OR_NULL(_fwnode_) &&				\
  	    !IS_ERR_OR_NULL(_fwnode_->secondary))					\

  		_ret_ = FWNODE_PROP_READ(_fwnode_->secondary, _propname_, _type_,	\
  				_proptype_, _val_, _nval_);				\
  	_ret_;										\
  })

  /**
   * fwnode_property_read_u8_array - return a u8 array property of firmware node
   * @fwnode: Firmware node to get the property of
   * @propname: Name of the property

   * @val: The values are stored here or %NULL to return the number of values

   * @nval: Size of the @val array
   *
   * Read an array of u8 properties with @propname from @fwnode and stores them to
   * @val if found.
   *

   * Return: number of values if @val was %NULL,
   *         %0 if the property was found (success),

   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO if the property is not an array of numbers,
   *	   %-EOVERFLOW if the size of the property is not as expected,
   *	   %-ENXIO if no suitable firmware interface is present.
   */
  int fwnode_property_read_u8_array(struct fwnode_handle *fwnode,
  				  const char *propname, u8 *val, size_t nval)
  {
  	return FWNODE_PROP_READ_ARRAY(fwnode, propname, u8, DEV_PROP_U8,
  				      val, nval);
  }
  EXPORT_SYMBOL_GPL(fwnode_property_read_u8_array);
  
  /**
   * fwnode_property_read_u16_array - return a u16 array property of firmware node
   * @fwnode: Firmware node to get the property of
   * @propname: Name of the property

   * @val: The values are stored here or %NULL to return the number of values

   * @nval: Size of the @val array
   *
   * Read an array of u16 properties with @propname from @fwnode and store them to
   * @val if found.
   *

   * Return: number of values if @val was %NULL,
   *         %0 if the property was found (success),

   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO if the property is not an array of numbers,
   *	   %-EOVERFLOW if the size of the property is not as expected,
   *	   %-ENXIO if no suitable firmware interface is present.
   */
  int fwnode_property_read_u16_array(struct fwnode_handle *fwnode,
  				   const char *propname, u16 *val, size_t nval)
  {
  	return FWNODE_PROP_READ_ARRAY(fwnode, propname, u16, DEV_PROP_U16,
  				      val, nval);
  }
  EXPORT_SYMBOL_GPL(fwnode_property_read_u16_array);
  
  /**
   * fwnode_property_read_u32_array - return a u32 array property of firmware node
   * @fwnode: Firmware node to get the property of
   * @propname: Name of the property

   * @val: The values are stored here or %NULL to return the number of values

   * @nval: Size of the @val array
   *
   * Read an array of u32 properties with @propname from @fwnode store them to
   * @val if found.
   *

   * Return: number of values if @val was %NULL,
   *         %0 if the property was found (success),

   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO if the property is not an array of numbers,
   *	   %-EOVERFLOW if the size of the property is not as expected,
   *	   %-ENXIO if no suitable firmware interface is present.
   */
  int fwnode_property_read_u32_array(struct fwnode_handle *fwnode,
  				   const char *propname, u32 *val, size_t nval)
  {
  	return FWNODE_PROP_READ_ARRAY(fwnode, propname, u32, DEV_PROP_U32,
  				      val, nval);
  }
  EXPORT_SYMBOL_GPL(fwnode_property_read_u32_array);
  
  /**
   * fwnode_property_read_u64_array - return a u64 array property firmware node
   * @fwnode: Firmware node to get the property of
   * @propname: Name of the property

   * @val: The values are stored here or %NULL to return the number of values

   * @nval: Size of the @val array
   *
   * Read an array of u64 properties with @propname from @fwnode and store them to
   * @val if found.
   *

   * Return: number of values if @val was %NULL,
   *         %0 if the property was found (success),

   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO if the property is not an array of numbers,
   *	   %-EOVERFLOW if the size of the property is not as expected,
   *	   %-ENXIO if no suitable firmware interface is present.
   */
  int fwnode_property_read_u64_array(struct fwnode_handle *fwnode,
  				   const char *propname, u64 *val, size_t nval)
  {
  	return FWNODE_PROP_READ_ARRAY(fwnode, propname, u64, DEV_PROP_U64,
  				      val, nval);
  }
  EXPORT_SYMBOL_GPL(fwnode_property_read_u64_array);

  static int __fwnode_property_read_string_array(struct fwnode_handle *fwnode,
  					       const char *propname,
  					       const char **val, size_t nval)
  {
  	if (is_of_node(fwnode))
  		return val ?
  			of_property_read_string_array(to_of_node(fwnode),
  						      propname, val, nval) :
  			of_property_count_strings(to_of_node(fwnode), propname);
  	else if (is_acpi_node(fwnode))
  		return acpi_node_prop_read(fwnode, propname, DEV_PROP_STRING,
  					   val, nval);
  	else if (is_pset_node(fwnode))
  		return val ?
  			pset_prop_read_string_array(to_pset_node(fwnode),
  						    propname, val, nval) :
  			pset_prop_count_elems_of_size(to_pset_node(fwnode),
  						      propname,
  						      sizeof(const char *));
  	return -ENXIO;
  }
  
  static int __fwnode_property_read_string(struct fwnode_handle *fwnode,
  					 const char *propname, const char **val)
  {
  	if (is_of_node(fwnode))
  		return of_property_read_string(to_of_node(fwnode), propname, val);
  	else if (is_acpi_node(fwnode))
  		return acpi_node_prop_read(fwnode, propname, DEV_PROP_STRING,
  					   val, 1);
  	else if (is_pset_node(fwnode))
  		return pset_prop_read_string(to_pset_node(fwnode), propname, val);
  	return -ENXIO;
  }

  /**
   * fwnode_property_read_string_array - return string array property of a node
   * @fwnode: Firmware node to get the property of
   * @propname: Name of the property

   * @val: The values are stored here or %NULL to return the number of values

   * @nval: Size of the @val array
   *
   * Read an string list property @propname from the given firmware node and store
   * them to @val if found.
   *

   * Return: number of values if @val was %NULL,
   *         %0 if the property was found (success),

   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO if the property is not an array of strings,
   *	   %-EOVERFLOW if the size of the property is not as expected,
   *	   %-ENXIO if no suitable firmware interface is present.
   */
  int fwnode_property_read_string_array(struct fwnode_handle *fwnode,
  				      const char *propname, const char **val,
  				      size_t nval)
  {

  	int ret;
  
  	ret = __fwnode_property_read_string_array(fwnode, propname, val, nval);

  	if (ret == -EINVAL && !IS_ERR_OR_NULL(fwnode) &&
  	    !IS_ERR_OR_NULL(fwnode->secondary))

  		ret = __fwnode_property_read_string_array(fwnode->secondary,
  							  propname, val, nval);
  	return ret;

  }
  EXPORT_SYMBOL_GPL(fwnode_property_read_string_array);
  
  /**
   * fwnode_property_read_string - return a string property of a firmware node
   * @fwnode: Firmware node to get the property of
   * @propname: Name of the property
   * @val: The value is stored here
   *
   * Read property @propname from the given firmware node and store the value into
   * @val if found.  The value is checked to be a string.
   *
   * Return: %0 if the property was found (success),
   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO or %-EILSEQ if the property is not a string,
   *	   %-ENXIO if no suitable firmware interface is present.
   */
  int fwnode_property_read_string(struct fwnode_handle *fwnode,
  				const char *propname, const char **val)
  {

  	int ret;
  
  	ret = __fwnode_property_read_string(fwnode, propname, val);

  	if (ret == -EINVAL && !IS_ERR_OR_NULL(fwnode) &&
  	    !IS_ERR_OR_NULL(fwnode->secondary))

  		ret = __fwnode_property_read_string(fwnode->secondary,
  						    propname, val);
  	return ret;

  }
  EXPORT_SYMBOL_GPL(fwnode_property_read_string);
  
  /**

   * fwnode_property_match_string - find a string in an array and return index
   * @fwnode: Firmware node to get the property of
   * @propname: Name of the property holding the array
   * @string: String to look for
   *
   * Find a given string in a string array and if it is found return the
   * index back.
   *
   * Return: %0 if the property was found (success),
   *	   %-EINVAL if given arguments are not valid,
   *	   %-ENODATA if the property does not have a value,
   *	   %-EPROTO if the property is not an array of strings,
   *	   %-ENXIO if no suitable firmware interface is present.
   */
  int fwnode_property_match_string(struct fwnode_handle *fwnode,
  	const char *propname, const char *string)
  {
  	const char **values;

  	int nval, ret;

  
  	nval = fwnode_property_read_string_array(fwnode, propname, NULL, 0);
  	if (nval < 0)
  		return nval;

  	if (nval == 0)
  		return -ENODATA;

  	values = kcalloc(nval, sizeof(*values), GFP_KERNEL);
  	if (!values)
  		return -ENOMEM;
  
  	ret = fwnode_property_read_string_array(fwnode, propname, values, nval);
  	if (ret < 0)
  		goto out;

  	ret = match_string(values, nval, string);
  	if (ret < 0)
  		ret = -ENODATA;

  out:
  	kfree(values);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(fwnode_property_match_string);
  
  /**

   * pset_free_set - releases memory allocated for copied property set
   * @pset: Property set to release
   *
   * Function takes previously copied property set and releases all the
   * memory allocated to it.
   */
  static void pset_free_set(struct property_set *pset)
  {
  	const struct property_entry *prop;
  	size_t i, nval;
  
  	if (!pset)
  		return;
  
  	for (prop = pset->properties; prop->name; prop++) {
  		if (prop->is_array) {
  			if (prop->is_string && prop->pointer.str) {
  				nval = prop->length / sizeof(const char *);
  				for (i = 0; i < nval; i++)
  					kfree(prop->pointer.str[i]);
  			}
  			kfree(prop->pointer.raw_data);
  		} else if (prop->is_string) {
  			kfree(prop->value.str);
  		}
  		kfree(prop->name);
  	}
  
  	kfree(pset->properties);
  	kfree(pset);
  }
  
  static int pset_copy_entry(struct property_entry *dst,
  			   const struct property_entry *src)
  {
  	const char **d, **s;
  	size_t i, nval;
  
  	dst->name = kstrdup(src->name, GFP_KERNEL);
  	if (!dst->name)
  		return -ENOMEM;
  
  	if (src->is_array) {

  		if (!src->length)
  			return -ENODATA;

  		if (src->is_string) {
  			nval = src->length / sizeof(const char *);
  			dst->pointer.str = kcalloc(nval, sizeof(const char *),
  						   GFP_KERNEL);
  			if (!dst->pointer.str)
  				return -ENOMEM;
  
  			d = dst->pointer.str;
  			s = src->pointer.str;
  			for (i = 0; i < nval; i++) {
  				d[i] = kstrdup(s[i], GFP_KERNEL);
  				if (!d[i] && s[i])
  					return -ENOMEM;
  			}
  		} else {
  			dst->pointer.raw_data = kmemdup(src->pointer.raw_data,
  							src->length, GFP_KERNEL);
  			if (!dst->pointer.raw_data)
  				return -ENOMEM;
  		}
  	} else if (src->is_string) {
  		dst->value.str = kstrdup(src->value.str, GFP_KERNEL);
  		if (!dst->value.str && src->value.str)
  			return -ENOMEM;
  	} else {
  		dst->value.raw_data = src->value.raw_data;
  	}
  
  	dst->length = src->length;
  	dst->is_array = src->is_array;
  	dst->is_string = src->is_string;
  
  	return 0;
  }
  
  /**
   * pset_copy_set - copies property set
   * @pset: Property set to copy
   *
   * This function takes a deep copy of the given property set and returns
   * pointer to the copy. Call device_free_property_set() to free resources
   * allocated in this function.
   *
   * Return: Pointer to the new property set or error pointer.
   */
  static struct property_set *pset_copy_set(const struct property_set *pset)
  {
  	const struct property_entry *entry;
  	struct property_set *p;
  	size_t i, n = 0;
  
  	p = kzalloc(sizeof(*p), GFP_KERNEL);
  	if (!p)
  		return ERR_PTR(-ENOMEM);
  
  	while (pset->properties[n].name)
  		n++;
  
  	p->properties = kcalloc(n + 1, sizeof(*entry), GFP_KERNEL);
  	if (!p->properties) {
  		kfree(p);
  		return ERR_PTR(-ENOMEM);
  	}
  
  	for (i = 0; i < n; i++) {
  		int ret = pset_copy_entry(&p->properties[i],
  					  &pset->properties[i]);
  		if (ret) {
  			pset_free_set(p);
  			return ERR_PTR(ret);
  		}
  	}
  
  	return p;
  }
  
  /**

   * device_remove_properties - Remove properties from a device object.

   * @dev: Device whose properties to remove.
   *
   * The function removes properties previously associated to the device

   * secondary firmware node with device_add_properties(). Memory allocated

   * to the properties will also be released.
   */

  void device_remove_properties(struct device *dev)

  {
  	struct fwnode_handle *fwnode;
  
  	fwnode = dev_fwnode(dev);
  	if (!fwnode)
  		return;
  	/*
  	 * Pick either primary or secondary node depending which one holds
  	 * the pset. If there is no real firmware node (ACPI/DT) primary
  	 * will hold the pset.
  	 */

  	if (is_pset_node(fwnode)) {
  		set_primary_fwnode(dev, NULL);

  		pset_free_set(to_pset_node(fwnode));

  	} else {
  		fwnode = fwnode->secondary;
  		if (!IS_ERR(fwnode) && is_pset_node(fwnode)) {
  			set_secondary_fwnode(dev, NULL);
  			pset_free_set(to_pset_node(fwnode));
  		}
  	}

  }

  EXPORT_SYMBOL_GPL(device_remove_properties);

  
  /**

   * device_add_properties - Add a collection of properties to a device object.

   * @dev: Device to add properties to.

   * @properties: Collection of properties to add.

   *

   * Associate a collection of device properties represented by @properties with
   * @dev as its secondary firmware node. The function takes a copy of
   * @properties.

   */

  int device_add_properties(struct device *dev, struct property_entry *properties)

  {

  	struct property_set *p, pset;

  	if (!properties)

  		return -EINVAL;

  	pset.properties = properties;
  
  	p = pset_copy_set(&pset);

  	if (IS_ERR(p))
  		return PTR_ERR(p);
  
  	p->fwnode.type = FWNODE_PDATA;
  	set_secondary_fwnode(dev, &p->fwnode);
  	return 0;
  }

  EXPORT_SYMBOL_GPL(device_add_properties);

  
  /**

   * device_get_next_child_node - Return the next child node handle for a device
   * @dev: Device to find the next child node for.
   * @child: Handle to one of the device's child nodes or a null handle.
   */
  struct fwnode_handle *device_get_next_child_node(struct device *dev,
  						 struct fwnode_handle *child)
  {
  	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
  		struct device_node *node;

  		node = of_get_next_available_child(dev->of_node, to_of_node(child));

  		if (node)
  			return &node->fwnode;
  	} else if (IS_ENABLED(CONFIG_ACPI)) {

  		return acpi_get_next_subnode(dev, child);

  	}
  	return NULL;
  }
  EXPORT_SYMBOL_GPL(device_get_next_child_node);
  
  /**

   * device_get_named_child_node - Return first matching named child node handle
   * @dev: Device to find the named child node for.
   * @childname: String to match child node name against.
   */
  struct fwnode_handle *device_get_named_child_node(struct device *dev,
  						  const char *childname)
  {
  	struct fwnode_handle *child;
  
  	/*
  	 * Find first matching named child node of this device.
  	 * For ACPI this will be a data only sub-node.
  	 */
  	device_for_each_child_node(dev, child) {
  		if (is_of_node(child)) {
  			if (!of_node_cmp(to_of_node(child)->name, childname))
  				return child;
  		} else if (is_acpi_data_node(child)) {
  			if (acpi_data_node_match(child, childname))
  				return child;
  		}
  	}
  
  	return NULL;
  }
  EXPORT_SYMBOL_GPL(device_get_named_child_node);
  
  /**

   * fwnode_handle_put - Drop reference to a device node
   * @fwnode: Pointer to the device node to drop the reference to.
   *
   * This has to be used when terminating device_for_each_child_node() iteration
   * with break or return to prevent stale device node references from being left
   * behind.
   */
  void fwnode_handle_put(struct fwnode_handle *fwnode)
  {
  	if (is_of_node(fwnode))

  		of_node_put(to_of_node(fwnode));

  }
  EXPORT_SYMBOL_GPL(fwnode_handle_put);
  
  /**
   * device_get_child_node_count - return the number of child nodes for device
   * @dev: Device to cound the child nodes for
   */
  unsigned int device_get_child_node_count(struct device *dev)
  {
  	struct fwnode_handle *child;
  	unsigned int count = 0;
  
  	device_for_each_child_node(dev, child)
  		count++;
  
  	return count;
  }
  EXPORT_SYMBOL_GPL(device_get_child_node_count);

  bool device_dma_supported(struct device *dev)
  {
  	/* For DT, this is always supported.
  	 * For ACPI, this depends on CCA, which
  	 * is determined by the acpi_dma_supported().
  	 */
  	if (IS_ENABLED(CONFIG_OF) && dev->of_node)
  		return true;
  
  	return acpi_dma_supported(ACPI_COMPANION(dev));
  }
  EXPORT_SYMBOL_GPL(device_dma_supported);
  
  enum dev_dma_attr device_get_dma_attr(struct device *dev)
  {
  	enum dev_dma_attr attr = DEV_DMA_NOT_SUPPORTED;
  
  	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
  		if (of_dma_is_coherent(dev->of_node))
  			attr = DEV_DMA_COHERENT;
  		else
  			attr = DEV_DMA_NON_COHERENT;
  	} else
  		attr = acpi_get_dma_attr(ACPI_COMPANION(dev));
  
  	return attr;
  }
  EXPORT_SYMBOL_GPL(device_get_dma_attr);

  /**

   * device_get_phy_mode - Get phy mode for given device

   * @dev:	Pointer to the given device
   *
   * The function gets phy interface string from property 'phy-mode' or
   * 'phy-connection-type', and return its index in phy_modes table, or errno in
   * error case.
   */
  int device_get_phy_mode(struct device *dev)
  {
  	const char *pm;
  	int err, i;
  
  	err = device_property_read_string(dev, "phy-mode", &pm);
  	if (err < 0)
  		err = device_property_read_string(dev,
  						  "phy-connection-type", &pm);
  	if (err < 0)
  		return err;
  
  	for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
  		if (!strcasecmp(pm, phy_modes(i)))
  			return i;
  
  	return -ENODEV;
  }
  EXPORT_SYMBOL_GPL(device_get_phy_mode);
  
  static void *device_get_mac_addr(struct device *dev,
  				 const char *name, char *addr,
  				 int alen)
  {
  	int ret = device_property_read_u8_array(dev, name, addr, alen);

  	if (ret == 0 && alen == ETH_ALEN && is_valid_ether_addr(addr))

  		return addr;
  	return NULL;
  }
  
  /**

   * device_get_mac_address - Get the MAC for a given device
   * @dev:	Pointer to the device
   * @addr:	Address of buffer to store the MAC in
   * @alen:	Length of the buffer pointed to by addr, should be ETH_ALEN
   *
   * Search the firmware node for the best MAC address to use.  'mac-address' is

   * checked first, because that is supposed to contain to "most recent" MAC
   * address. If that isn't set, then 'local-mac-address' is checked next,
   * because that is the default address.  If that isn't set, then the obsolete
   * 'address' is checked, just in case we're using an old device tree.
   *
   * Note that the 'address' property is supposed to contain a virtual address of
   * the register set, but some DTS files have redefined that property to be the
   * MAC address.
   *
   * All-zero MAC addresses are rejected, because those could be properties that

   * exist in the firmware tables, but were not updated by the firmware.  For
   * example, the DTS could define 'mac-address' and 'local-mac-address', with
   * zero MAC addresses.  Some older U-Boots only initialized 'local-mac-address'.
   * In this case, the real MAC is in 'local-mac-address', and 'mac-address'
   * exists but is all zeros.

  */
  void *device_get_mac_address(struct device *dev, char *addr, int alen)
  {

  	char *res;

  	res = device_get_mac_addr(dev, "mac-address", addr, alen);
  	if (res)
  		return res;
  
  	res = device_get_mac_addr(dev, "local-mac-address", addr, alen);
  	if (res)
  		return res;

  
  	return device_get_mac_addr(dev, "address", addr, alen);
  }
  EXPORT_SYMBOL(device_get_mac_address);