Commit 1e291b14 authored by Michael Ellerman's avatar Michael Ellerman Committed by Paul Mackerras
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of: Add helpers for finding device nodes which have a given property 



This commit adds a routine for finding a device node which has a
certain property.  The contents of the property are not taken into
account, merely the presence or absence of the property.

Based on that routine, we add a for_each_ macro for iterating over all
nodes that have a certain property.

Signed-off-by: default avatarMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent ae564c63

drivers/of/base.c

+35 −0
Original line number Diff line number Diff line
@@ -328,6 +328,41 @@ struct device_node *of_find_compatible_node(struct device_node *from, 
}

EXPORT_SYMBOL(of_find_compatible_node);



/**

 *	of_find_node_with_property - Find a node which has a property with

 *                                   the given name.

 *	@from:		The node to start searching from or NULL, the node

 *			you pass will not be searched, only the next one

 *			will; typically, you pass what the previous call

 *			returned. of_node_put() will be called on it

 *	@prop_name:	The name of the property to look for.

 *

 *	Returns a node pointer with refcount incremented, use

 *	of_node_put() on it when done.

 */

struct device_node *of_find_node_with_property(struct device_node *from,

	const char *prop_name)

{

	struct device_node *np;

	struct property *pp;



	read_lock(&devtree_lock);

	np = from ? from->allnext : allnodes;

	for (; np; np = np->allnext) {

		for (pp = np->properties; pp != 0; pp = pp->next) {

			if (of_prop_cmp(pp->name, prop_name) == 0) {

				of_node_get(np);

				goto out;

			}

		}

	}

out:

	of_node_put(from);

	read_unlock(&devtree_lock);

	return np;

}

EXPORT_SYMBOL(of_find_node_with_property);



/**

 * of_match_node - Tell if an device_node has a matching of_match structure

 *	@matches:	array of of device match structures to search in

include/linux/of.h

+6 −0
Original line number Diff line number Diff line
@@ -57,6 +57,12 @@ extern struct device_node *of_get_next_child(const struct device_node *node, 
	for (child = of_get_next_child(parent, NULL); child != NULL; \

	     child = of_get_next_child(parent, child))



extern struct device_node *of_find_node_with_property(

	struct device_node *from, const char *prop_name);

#define for_each_node_with_property(dn, prop_name) \

	for (dn = of_find_node_with_property(NULL, prop_name); dn; \

	     dn = of_find_node_with_property(dn, prop_name))



extern struct property *of_find_property(const struct device_node *np,

					 const char *name,

					 int *lenp);