[PATCH 3/5] device property: Add a function to obtain a node's prefix

From: Sakari Ailus
Date: Fri Mar 22 2019 - 11:29:54 EST


The prefix is used for printing purpose before a node, and it also works
as a separator between two nodes.

Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
drivers/acpi/property.c | 22 ++++++++++++++++++++++
drivers/base/property.c | 13 +++++++++++++
drivers/of/property.c | 10 ++++++++++
include/linux/fwnode.h | 2 ++
include/linux/property.h | 1 +
5 files changed, 48 insertions(+)

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 8c9a4c02cde2..c167fd748f86 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -1314,6 +1314,27 @@ static const char *acpi_fwnode_get_name(const struct fwnode_handle *fwnode)
return adev ? acpi_device_bid(adev) : NULL;
}

+static const char *
+acpi_fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
+{
+ struct fwnode_handle *parent;
+
+ parent = fwnode_get_parent(fwnode);
+ /* Root node. */
+ if (!parent)
+ return "";
+
+ parent = fwnode_get_next_parent(parent);
+ /* Second node from the root; no prefix here either. */
+ if (!parent)
+ return "";
+
+ fwnode_handle_put(parent);
+
+ /* ACPI device or data node. */
+ return ".";
+}
+
static struct fwnode_handle *
acpi_fwnode_get_parent(struct fwnode_handle *fwnode)
{
@@ -1355,6 +1376,7 @@ acpi_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
.get_next_child_node = acpi_get_next_subnode, \
.get_named_child_node = acpi_fwnode_get_named_child_node, \
.get_name = acpi_fwnode_get_name, \
+ .get_name_prefix = acpi_fwnode_get_name_prefix, \
.get_reference_args = acpi_fwnode_get_reference_args, \
.graph_get_next_endpoint = \
acpi_graph_get_next_endpoint, \
diff --git a/drivers/base/property.c b/drivers/base/property.c
index 7ee3786bcde3..68b74e53864b 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -545,6 +545,19 @@ const char *fwnode_get_name(const struct fwnode_handle *fwnode)
}

/**
+ * fwnode_get_name_prefix - Return the prefix of node for printing purposes
+ *
+ * @fwnode: The firmware node
+ *
+ * Returns the prefix of a node, intended to be printed right before the node.
+ * The prefix works also as a separator between the nodes.
+ */
+const char *fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
+{
+ return fwnode_call_ptr_op(fwnode, get_name_prefix);
+}
+
+/**
* fwnode_get_parent - Return parent firwmare node
* @fwnode: Firmware whose parent is retrieved
*
diff --git a/drivers/of/property.c b/drivers/of/property.c
index f0a7b78f2d9f..8fed3b142b41 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -877,6 +877,15 @@ static const char *of_fwnode_get_name(const struct fwnode_handle *fwnode)
return kbasename(to_of_node(fwnode)->full_name);
}

+static const char *of_fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
+{
+ /* Root needs no prefix here (its name is "/"). */
+ if (!to_of_node(fwnode)->parent)
+ return "";
+
+ return "/";
+}
+
static struct fwnode_handle *
of_fwnode_get_parent(const struct fwnode_handle *fwnode)
{
@@ -999,6 +1008,7 @@ const struct fwnode_operations of_fwnode_ops = {
.property_read_int_array = of_fwnode_property_read_int_array,
.property_read_string_array = of_fwnode_property_read_string_array,
.get_name = of_fwnode_get_name,
+ .get_name_prefix = of_fwnode_get_name_prefix,
.get_parent = of_fwnode_get_parent,
.get_next_child_node = of_fwnode_get_next_child_node,
.get_named_child_node = of_fwnode_get_named_child_node,
diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index 85b7fa4dc727..592ac6936e14 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -60,6 +60,7 @@ struct fwnode_reference_args {
* @property_read_string_array: Read an array of string properties. Return zero
* on success, a negative error code otherwise.
* @get_name: Return the name of an fwnode.
+ * @get_name_prefix: Get a prefix for a node (for printing purposes).
* @get_parent: Return the parent of an fwnode.
* @get_next_child_node: Return the next child node in an iteration.
* @get_named_child_node: Return a child node with a given name.
@@ -87,6 +88,7 @@ struct fwnode_operations {
const char *propname, const char **val,
size_t nval);
const char *(*get_name)(const struct fwnode_handle *fwnode);
+ const char *(*get_name_prefix)(const struct fwnode_handle *fwnode);
struct fwnode_handle *(*get_parent)(const struct fwnode_handle *fwnode);
struct fwnode_handle *
(*get_next_child_node)(const struct fwnode_handle *fwnode,
diff --git a/include/linux/property.h b/include/linux/property.h
index 2f5df900e310..0ea466ee8c3d 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -79,6 +79,7 @@ int fwnode_property_get_reference_args(const struct fwnode_handle *fwnode,
struct fwnode_reference_args *args);

const char *fwnode_get_name(const struct fwnode_handle *fwnode);
+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);
--
2.11.0