Commit 1fcc67e3 authored by Chen-Yu Tsai's avatar Chen-Yu Tsai Committed by Wolfram Sang
Browse files

of: base: Add for_each_child_of_node_with_prefix() 



There are cases where drivers would go through child device nodes and
operate on only the ones whose node name starts with a given prefix.

Provide a helper for these users. This will mainly be used in a
subsequent patch that implements a hardware component prober for I2C
busses.

Signed-off-by: default avatarChen-Yu Tsai <wenst@chromium.org>
Reviewed-by: default avatarRob Herring (Arm) <robh@kernel.org>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
parent 81de291d

drivers/of/base.c

+35 −0
Original line number Diff line number Diff line
@@ -644,6 +644,41 @@ struct device_node *of_get_next_child(const struct device_node *node, 
}

EXPORT_SYMBOL(of_get_next_child);



/**

 * of_get_next_child_with_prefix - Find the next child node with prefix

 * @node:	parent node

 * @prev:	previous child of the parent node, or NULL to get first

 *

 * This function is like of_get_next_child(), except that it automatically

 * skips any nodes whose name doesn't have the given prefix.

 *

 * Return: A node pointer with refcount incremented, use

 * of_node_put() on it when done.

 */

struct device_node *of_get_next_child_with_prefix(const struct device_node *node,

						  struct device_node *prev,

						  const char *prefix)

{

	struct device_node *next;

	unsigned long flags;



	if (!node)

		return NULL;



	raw_spin_lock_irqsave(&devtree_lock, flags);

	next = prev ? prev->sibling : node->child;

	for (; next; next = next->sibling) {

		if (!of_node_name_prefix(next, prefix))

			continue;

		if (of_node_get(next))

			break;

	}

	of_node_put(prev);

	raw_spin_unlock_irqrestore(&devtree_lock, flags);

	return next;

}

EXPORT_SYMBOL(of_get_next_child_with_prefix);



static struct device_node *of_get_next_status_child(const struct device_node *node,

						    struct device_node *prev,

						    bool (*checker)(const struct device_node *))

include/linux/of.h

+9 −0
Original line number Diff line number Diff line
@@ -289,6 +289,9 @@ extern struct device_node *of_get_parent(const struct device_node *node); 
extern struct device_node *of_get_next_parent(struct device_node *node);

extern struct device_node *of_get_next_child(const struct device_node *node,

					     struct device_node *prev);

extern struct device_node *of_get_next_child_with_prefix(const struct device_node *node,

							 struct device_node *prev,

							 const char *prefix);

extern struct device_node *of_get_next_available_child(

	const struct device_node *node, struct device_node *prev);

extern struct device_node *of_get_next_reserved_child(
@@ -1468,6 +1471,12 @@ static inline int of_property_read_s32(const struct device_node *np, 
	     child != NULL;						\

	     child = of_get_next_child(parent, child))



#define for_each_child_of_node_with_prefix(parent, child, prefix)	\

	for (struct device_node *child __free(device_node) =		\

	     of_get_next_child_with_prefix(parent, NULL, prefix);	\

	     child != NULL;						\

	     child = of_get_next_child_with_prefix(parent, child, prefix))



#define for_each_available_child_of_node(parent, child) \

	for (child = of_get_next_available_child(parent, NULL); child != NULL; \

	     child = of_get_next_available_child(parent, child))