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authorAdam Thomson <Adam.Thomson.Opensource@diasemi.com>2016-06-21 20:50:20 +0300
committerMark Brown <broonie@kernel.org>2016-06-26 14:39:03 +0300
commit613e97218ccbd7f33895cad4525d861810a9d5d5 (patch)
tree2e13158ccc751520e2f69f030c3c98814e318768 /drivers/base
parent1a695a905c18548062509178b98bc91e67510864 (diff)
downloadlinux-613e97218ccbd7f33895cad4525d861810a9d5d5.tar.xz
device property: Add function to search for named child of device
For device nodes in both DT and ACPI, it possible to have named child nodes which contain properties (an existing example being gpio-leds). This adds a function to find a named child node for a device which can be used by drivers for property retrieval. For DT data node name matching, of_node_cmp() and similar functions are made available outside of CONFIG_OF block so the new function can reference these for DT and non-DT builds. For ACPI data node name matching, a helper function is also added which returns false if CONFIG_ACPI is not set, otherwise it performs a string comparison on the data node name. This avoids using the acpi_data_node struct for non CONFIG_ACPI builds, which would otherwise cause a build failure. Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com> Acked-by: Sathyanarayana Nujella <sathyanarayana.nujella@intel.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/property.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/base/property.c b/drivers/base/property.c
index f38c21de29b7..43a36d68c3fd 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -888,6 +888,34 @@ struct fwnode_handle *device_get_next_child_node(struct device *dev,
EXPORT_SYMBOL_GPL(device_get_next_child_node);
/**
+ * device_get_named_child_node - Return first matching named child node handle
+ * @dev: Device to find the named child node for.
+ * @childname: String to match child node name against.
+ */
+struct fwnode_handle *device_get_named_child_node(struct device *dev,
+ const char *childname)
+{
+ struct fwnode_handle *child;
+
+ /*
+ * Find first matching named child node of this device.
+ * For ACPI this will be a data only sub-node.
+ */
+ device_for_each_child_node(dev, child) {
+ if (is_of_node(child)) {
+ if (!of_node_cmp(to_of_node(child)->name, childname))
+ return child;
+ } else if (is_acpi_data_node(child)) {
+ if (acpi_data_node_match(child, childname))
+ return child;
+ }
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(device_get_named_child_node);
+
+/**
* fwnode_handle_put - Drop reference to a device node
* @fwnode: Pointer to the device node to drop the reference to.
*