Commit b5d3e2fb authored by Saravana Kannan's avatar Saravana Kannan Committed by Greg Kroah-Hartman
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device property: Add fwnode_is_ancestor_of() and fwnode_get_next_parent_dev() 



Add fwnode_is_ancestor_of() helper function to check if a fwnode is an
ancestor of another fwnode.

Add fwnode_get_next_parent_dev() helper function that take as input a
fwnode and finds the closest ancestor fwnode that has a corresponding
struct device and returns that struct device.

Signed-off-by: default avatarSaravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-11-saravanak@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ac66c5bb

drivers/base/property.c

+52 −0
Original line number Diff line number Diff line
@@ -614,6 +614,31 @@ struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode) 
}

EXPORT_SYMBOL_GPL(fwnode_get_next_parent);



/**

 * fwnode_get_next_parent_dev - Find device of closest ancestor fwnode

 * @fwnode: firmware node

 *

 * Given a firmware node (@fwnode), this function finds its closest ancestor

 * firmware node that has a corresponding struct device and returns that struct

 * device.

 *

 * The caller of this function is expected to call put_device() on the returned

 * device when they are done.

 */

struct device *fwnode_get_next_parent_dev(struct fwnode_handle *fwnode)

{

	struct device *dev = NULL;



	fwnode_handle_get(fwnode);

	do {

		fwnode = fwnode_get_next_parent(fwnode);

		if (fwnode)

			dev = get_dev_from_fwnode(fwnode);

	} while (fwnode && !dev);

	fwnode_handle_put(fwnode);

	return dev;

}



/**

 * fwnode_count_parents - Return the number of parents a node has

 * @fwnode: The node the parents of which are to be counted
@@ -660,6 +685,33 @@ struct fwnode_handle *fwnode_get_nth_parent(struct fwnode_handle *fwnode, 
}

EXPORT_SYMBOL_GPL(fwnode_get_nth_parent);



/**

 * fwnode_is_ancestor_of - Test if @test_ancestor is ancestor of @test_child

 * @test_ancestor: Firmware which is tested for being an ancestor

 * @test_child: Firmware which is tested for being the child

 *

 * A node is considered an ancestor of itself too.

 *

 * Returns true if @test_ancestor is an ancestor of @test_child.

 * Otherwise, returns false.

 */

bool fwnode_is_ancestor_of(struct fwnode_handle *test_ancestor,

				  struct fwnode_handle *test_child)

{

	if (!test_ancestor)

		return false;



	fwnode_handle_get(test_child);

	while (test_child) {

		if (test_child == test_ancestor) {

			fwnode_handle_put(test_child);

			return true;

		}

		test_child = fwnode_get_next_parent(test_child);

	}

	return false;

}



/**

 * 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
@@ -85,9 +85,12 @@ const char *fwnode_get_name_prefix(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);

struct device *fwnode_get_next_parent_dev(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);

bool fwnode_is_ancestor_of(struct fwnode_handle *test_ancestor,

				  struct fwnode_handle *test_child);

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(