Commit 87e5e95d authored by Sakari Ailus's avatar Sakari Ailus Committed by Rafael J. Wysocki
Browse files

device property: Add functions for accessing node's parents 



Add two convenience functions for accessing node's parents:

fwnode_count_parents() returns the number of parent nodes a given node
has. fwnode_get_nth_parent() returns node's parent at a given distance
from the node itself.

Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent a57b7fb7

drivers/base/property.c

+46 −0
Original line number Diff line number Diff line
@@ -590,6 +590,52 @@ struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode) 
}

EXPORT_SYMBOL_GPL(fwnode_get_next_parent);



/**

 * fwnode_count_parents - Return the number of parents a node has

 * @fwnode: The node the parents of which are to be counted

 *

 * Returns the number of parents a node has.

 */

unsigned int fwnode_count_parents(const struct fwnode_handle *fwnode)

{

	struct fwnode_handle *__fwnode;

	unsigned int count;



	__fwnode = fwnode_get_parent(fwnode);



	for (count = 0; __fwnode; count++)

		__fwnode = fwnode_get_next_parent(__fwnode);



	return count;

}

EXPORT_SYMBOL_GPL(fwnode_count_parents);



/**

 * fwnode_get_nth_parent - Return an nth parent of a node

 * @fwnode: The node the parent of which is requested

 * @depth: Distance of the parent from the node

 *

 * Returns the nth parent of a node. If there is no parent at the requested

 * @depth, %NULL is returned. If @depth is 0, the functionality is equivalent to

 * fwnode_handle_get(). For @depth == 1, it is fwnode_get_parent() and so on.

 *

 * The caller is responsible for calling fwnode_handle_put() for the returned

 * node.

 */

struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwnode,

					    unsigned int depth)

{

	unsigned int i;



	fwnode_handle_get(fwnode);



	for (i = 0; i < depth && fwnode; i++)

		fwnode = fwnode_get_next_parent(fwnode);



	return fwnode;

}

EXPORT_SYMBOL_GPL(fwnode_get_nth_parent);



/**

 * fwnode_get_next_child_node - Return the next child node handle for a node

 * @fwnode: Firmware node to find the next child node for.

include/linux/property.h

+3 −0
Original line number Diff line number Diff line
@@ -83,6 +83,9 @@ struct fwnode_handle *fwnode_find_reference(const struct fwnode_handle *fwnode, 
struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode);

struct fwnode_handle *fwnode_get_next_parent(

	struct fwnode_handle *fwnode);

unsigned int fwnode_count_parents(const struct fwnode_handle *fwn);

struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwn,

					    unsigned int depth);

struct fwnode_handle *fwnode_get_next_child_node(

	const struct fwnode_handle *fwnode, struct fwnode_handle *child);

struct fwnode_handle *fwnode_get_next_available_child_node(

CRA Git | Maintained and supported by SUSTech CRA and CCSE