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: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-11-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Saravana Kannan 2020-11-20 18:02:25 -08:00 committed by Greg Kroah-Hartman
parent ac66c5bbb4
commit b5d3e2fbcb
2 changed files with 55 additions and 0 deletions

View file

@ -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.

View file

@ -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(