From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sakari Ailus Subject: [PATCH 1/5] device property: Add functions for accessing node's parents Date: Fri, 22 Mar 2019 17:29:26 +0200 Message-ID: <20190322152930.16642-2-sakari.ailus@linux.intel.com> References: <20190322152930.16642-1-sakari.ailus@linux.intel.com> Return-path: In-Reply-To: <20190322152930.16642-1-sakari.ailus@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Petr Mladek , linux-kernel@vger.kernel.org, rafael@kernel.org Cc: Andy Shevchenko , linux-acpi@vger.kernel.org, devicetree@vger.kernel.org List-Id: linux-acpi@vger.kernel.org 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. Also reorder fwnode_get_parent() in property.c according to the same order as in property.h. Signed-off-by: Sakari Ailus --- drivers/base/property.c | 61 ++++++++++++++++++++++++++++++++++++++++++------ include/linux/property.h | 3 +++ 2 files changed, 57 insertions(+), 7 deletions(-) diff --git a/drivers/base/property.c b/drivers/base/property.c index 8b91ab380d14..3f5ff6b23ae4 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -533,6 +533,19 @@ int device_add_properties(struct device *dev, EXPORT_SYMBOL_GPL(device_add_properties); /** + * fwnode_get_parent - Return parent firwmare node + * @fwnode: Firmware whose parent is retrieved + * + * Return parent firmware node of the given node if possible or %NULL if no + * parent was available. + */ +struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode) +{ + return fwnode_call_ptr_op(fwnode, get_parent); +} +EXPORT_SYMBOL_GPL(fwnode_get_parent); + +/** * fwnode_get_next_parent - Iterate to the node's parent * @fwnode: Firmware whose parent is retrieved * @@ -554,17 +567,51 @@ struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode) EXPORT_SYMBOL_GPL(fwnode_get_next_parent); /** - * fwnode_get_parent - Return parent firwmare node - * @fwnode: Firmware whose parent is retrieved + * fwnode_count_parents - Return the number of parents a node has * - * Return parent firmware node of the given node if possible or %NULL if no - * parent was available. + * @fwnode: The node the parents of which are to be counted + * + * Returns the number of parents a node has. */ -struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode) +unsigned int fwnode_count_parents(struct fwnode_handle *fwnode) { - return fwnode_call_ptr_op(fwnode, get_parent); + unsigned int count; + + fwnode_handle_get(fwnode); + + for (count = 0; fwnode; count++) + fwnode = fwnode_get_next_parent(fwnode); + + return count - 1; } -EXPORT_SYMBOL_GPL(fwnode_get_parent); +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 @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 diff --git a/include/linux/property.h b/include/linux/property.h index 65d3420dd5d1..1164ac974ee8 100644 --- a/include/linux/property.h +++ b/include/linux/property.h @@ -81,6 +81,9 @@ int fwnode_property_get_reference_args(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(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( -- 2.11.0