Re: [PATCH v5 02/10] property: Add functions to count named child nodes

Heikki Krogerus
2025-03-03T11:50:21Z

Hi,

> +/**
> + * fwnode_get_child_node_count_named - number of child nodes with given name
> + * @fwnode: Node which child nodes are counted.
> + * @name: String to match child node name against.
> + *
> + * Scan child nodes and count all the nodes with a specific name. Return the
> + * number of found nodes. Potential '@number' -ending for scanned names is
> + * ignored. Eg,
> + * device_get_child_node_count(dev, "channel");
> + * would match all the nodes:
> + * channel { }, channel@0 {}, channel@0xabba {}...
> + *
> + * Return: the number of child nodes with a matching name for a given device.
> + */
> +unsigned int fwnode_get_child_node_count_named(const struct fwnode_handle *fwnode,
> + const char *name)
> +{
> + struct fwnode_handle *child;
> + unsigned int count = 0;
> +
> + fwnode_for_each_child_node(fwnode, child)
> + if (fwnode_name_eq(child, name))
> + count++;
> +
> + return count;
> +}
> +EXPORT_SYMBOL_GPL(fwnode_get_child_node_count_named);
> +
> +/**
> + * device_get_child_node_count_named - number of child nodes with given name
> + * @dev: Device to count the child nodes for.
> + * @name: String to match child node name against.
> + *
> + * Scan device's child nodes and find all the nodes with a specific name and
> + * return the number of found nodes. Potential '@number' -ending for scanned
> + * names is ignored. Eg,
> + * device_get_child_node_count(dev, "channel");
> + * would match all the nodes:
> + * channel { }, channel@0 {}, channel@0xabba {}...
> + *
> + * Return: the number of child nodes with a matching name for a given device.
> + */
> +unsigned int device_get_child_node_count_named(const struct device *dev,
> + const char *name)
> +{
> + const struct fwnode_handle *fwnode = dev_fwnode(dev);
> +
> + if (!fwnode)
> + return -EINVAL;
> +
> + if (IS_ERR(fwnode))
> + return PTR_ERR(fwnode);
> +
> + return fwnode_get_child_node_count_named(fwnode, name);
> +}
> +EXPORT_SYMBOL_GPL(device_get_child_node_count_named);

Sorry if I missed something in the v4 thread, but why not do all the
checks in fwnode_get_child_node_count_named(), and make this an inline
function?

static inline unsigned int
device_get_child_node_count_named(const struct device *dev, const char *name)
{
return fwnode_get_child_node_count_named(dev_fwnode(fwnode), name);
}

thanks,

--
heikki