path: root/drivers/base/swnode.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Software nodes for the firmware node framework.
 *
 * Copyright (C) 2018, Intel Corporation
 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
 */

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/property.h>
#include <linux/slab.h>

#include "base.h"

struct swnode {
	struct kobject kobj;
	struct fwnode_handle fwnode;
	const struct software_node *node;
	int id;

	/* hierarchy */
	struct ida child_ids;
	struct list_head entry;
	struct list_head children;
	struct swnode *parent;

	unsigned int allocated:1;
	unsigned int managed:1;
};

static DEFINE_IDA(swnode_root_ids);
static struct kset *swnode_kset;

#define kobj_to_swnode(_kobj_) container_of(_kobj_, struct swnode, kobj)

static const struct fwnode_operations software_node_ops;

bool is_software_node(const struct fwnode_handle *fwnode)
{
	return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &software_node_ops;
}
EXPORT_SYMBOL_GPL(is_software_node);

#define to_swnode(__fwnode)						\
	({								\
		typeof(__fwnode) __to_swnode_fwnode = __fwnode;		\
									\
		is_software_node(__to_swnode_fwnode) ?			\
			container_of(__to_swnode_fwnode,		\
				     struct swnode, fwnode) : NULL;	\
	})

static inline struct swnode *dev_to_swnode(struct device *dev)
{
	struct fwnode_handle *fwnode = dev_fwnode(dev);

	if (!fwnode)
		return NULL;

	if (!is_software_node(fwnode))
		fwnode = fwnode->secondary;

	return to_swnode(fwnode);
}

static struct swnode *
software_node_to_swnode(const struct software_node *node)
{
	struct swnode *swnode = NULL;
	struct kobject *k;

	if (!node)
		return NULL;

	spin_lock(&swnode_kset->list_lock);

	list_for_each_entry(k, &swnode_kset->list, entry) {
		swnode = kobj_to_swnode(k);
		if (swnode->node == node)
			break;
		swnode = NULL;
	}

	spin_unlock(&swnode_kset->list_lock);

	return swnode;
}

const struct software_node *to_software_node(const struct fwnode_handle *fwnode)
{
	const struct swnode *swnode = to_swnode(fwnode);

	return swnode ? swnode->node : NULL;
}
EXPORT_SYMBOL_GPL(to_software_node);

struct fwnode_handle *software_node_fwnode(const struct software_node *node)
{
	struct swnode *swnode = software_node_to_swnode(node);

	return swnode ? &swnode->fwnode : NULL;
}
EXPORT_SYMBOL_GPL(software_node_fwnode);

/* -------------------------------------------------------------------------- */
/* property_entry processing */

static const struct property_entry *
property_entry_get(const struct property_entry *prop, const char *name)
{
	if (!prop)
		return NULL;

	for (; prop->name; prop++)
		if (!strcmp(name, prop->name))
			return prop;

	return NULL;
}

static const void *property_get_pointer(const struct property_entry *prop)
{
	if (!prop->length)
		return NULL;

	return prop->is_inline ? &prop->value : prop->pointer;
}

static const void *property_entry_find(const struct property_entry *props,
				       const char *propname, size_t length)
{
	const struct property_entry *prop;
	const void *pointer;

	prop = property_entry_get(props, propname);
	if (!prop)
		return ERR_PTR(-EINVAL);
	pointer = property_get_pointer(prop);
	if (!pointer)
		return ERR_PTR(-ENODATA);
	if (length > prop->length)
		return ERR_PTR(-EOVERFLOW);
	return pointer;
}

static int
property_entry_count_elems_of_size(const struct property_entry *props,
				   const char *propname, size_t length)
{
	const struct property_entry *prop;

	prop = property_entry_get(props, propname