[PATCH v6 07/12] device property: Add a function to obtain a node's prefix

Sakari Ailus
2019-09-10T08:47:49Z

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@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org> (for OF)
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
drivers/acpi/property.c | 22 ++++++++++++++++++++++
drivers/base/property.c | 12 ++++++++++++
drivers/base/swnode.c | 22 ++++++++++++++++++++++
drivers/of/property.c | 10 ++++++++++
include/linux/fwnode.h | 2 ++
include/linux/property.h | 1 +
6 files changed, 69 insertions(+)

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index 5a9397a390f41..466239d3bb345 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -1336,6 +1336,27 @@ static const char *acpi_fwnode_get_name(const struct fwnode_handle *fwnode)
return acpi_device_bid(adev);
}

+static const char *
+acpi_fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
+{
+ struct fwnode_handle *parent;
+
+ /* Is this the root node? */
+ parent = fwnode_get_parent(fwnode);
+ if (!parent)
+ return "";
+
+ /* Is this 2nd node from the root? */
+ parent = fwnode_get_next_parent(parent);
+ 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)
{
@@ -1377,6 +1398,7 @@ 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 9b5ec88e72d8b..511f6d7acdfe4 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -567,6 +567,18 @@ const char *fwnode_get_name(const struct fwnode_handle *fwnode)
return fwnode_call_ptr_op(fwnode, get_name);
}

+/**
+ * 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/base/swnode.c b/drivers/base/swnode.c
index ccbc3d9d6c5f5..6a8c427355f8d 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -526,6 +526,27 @@ software_node_get_name(const struct fwnode_handle *fwnode)
return kobject_name(&swnode->kobj);
}

+static const char *
+software_node_get_name_prefix(const struct fwnode_handle *fwnode)
+{
+ struct fwnode_handle *parent;
+ const char *prefix;
+
+ parent = fwnode_get_parent(fwnode);
+ if (!parent)
+ return "";
+
+ /* Figure out the prefix from the parents. */
+ while (is_software_node(parent))
+ parent = fwnode_get_next_parent(parent);
+
+ prefix = fwnode_get_name_prefix(parent);
+ fwnode_handle_put(parent);
+
+ /* Guess something if prefix was NULL. */
+ return prefix ?: "/";
+}
+
static struct fwnode_handle *
software_node_get_parent(const struct fwnode_handle *fwnode)
{
@@ -627,6 +648,7 @@ static const struct fwnode_operations software_node_ops = {
.property_read_int_array = software_node_read_int_array,
.property_read_string_array = software_node_read_string_array,
.get_name = software_node_get_name,
+ .get_name_prefix = software_node_get_name_prefix,
.get_parent = software_node_get_parent,
.get_next_child_node = software_node_get_next_child,
.get_named_child_node = software_node_get_named_child_node,
diff --git a/drivers/of/property.c b/drivers/of/property.c
index 5bed634551ea6..e8202f61a5d93 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 c331e0ef31e80..755709703fe6f 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -57,6 +57,7 @@ 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.
@@ -84,6 +85,7 @@ 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 ebc5e2016bb66..c40fcfc5774a7 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -81,6 +81,7 @@ struct fwnode_handle *fwnode_find_reference(const struct fwnode_handle *fwnode,
unsigned int index);

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);
--
2.20.1