[PATCH v4 1/4] device property: Introduce fwnode_get_name()

From: Heikki Krogerus
Date: Tue Nov 27 2018 - 09:29:03 EST


This helper returns the name of the node. The name is
primarily expected to be returned from a new fwnode
operation meant for this purpose, but when no name is
returned, the helper will also attempt to read a device
property "name".

Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
---
drivers/base/property.c | 36 ++++++++++++++++++++++++++++++++++++
include/linux/fwnode.h | 3 +++
include/linux/property.h | 2 ++
3 files changed, 41 insertions(+)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 240ab5230ff6..8bd35b44d9ec 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -1156,6 +1156,42 @@ void fwnode_handle_put(struct fwnode_handle *fwnode)
}
EXPORT_SYMBOL_GPL(fwnode_handle_put);

+/**
+ * fwnode_get_name - Copy the name of an fwnode to a buffer
+ * @fwnode: Pointer to the node
+ * @buf: Buffer where the name is copied to
+ * @len: Size of the buffer
+ *
+ * Copies the node name of @fwnode to @buf. The routine attempts to first use
+ * the get_name fwnode op of @fwnode, and if it fails, the routine attempts to
+ * read a property "name".
+ *
+ * NOTE: @buf must be large enough to accommodate the name and trailing '\0'.
+ *
+ * Returns 0 on success or errno in case of an error.
+ */
+int fwnode_get_name(const struct fwnode_handle *fwnode, char *buf, size_t len)
+{
+ const char *name;
+ int ret;
+
+ ret = fwnode_call_int_op(fwnode, get_name, buf, len);
+ if (ret == 0 || ret == -EOVERFLOW)
+ return ret;
+
+ ret = fwnode_call_int_op(fwnode, property_read_string_array,
+ "name", &name, 1);
+ if (ret)
+ return ret;
+
+ if (len < strlen(name) + 1)
+ return -EOVERFLOW;
+
+ sprintf(buf, "%s", name);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fwnode_get_name);
+
/**
* fwnode_device_is_available - check if a device is available for use
* @fwnode: Pointer to the fwnode of the device.
diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index faebf0ca0686..a211b55a5da1 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -52,6 +52,7 @@ struct fwnode_reference_args {
* struct fwnode_operations - Operations for fwnode interface
* @get: Get a reference to an fwnode.
* @put: Put a reference to an fwnode.
+ * @get_name: Get the name of an fwnode
* @device_get_match_data: Return the device driver match data.
* @property_present: Return true if a property is present.
* @property_read_integer_array: Read an array of integer properties. Return
@@ -72,6 +73,8 @@ struct fwnode_reference_args {
struct fwnode_operations {
struct fwnode_handle *(*get)(struct fwnode_handle *fwnode);
void (*put)(struct fwnode_handle *fwnode);
+ int (*get_name)(const struct fwnode_handle *fwnode, char *buf,
+ size_t len);
bool (*device_is_available)(const struct fwnode_handle *fwnode);
const void *(*device_get_match_data)(const struct fwnode_handle *fwnode,
const struct device *dev);
diff --git a/include/linux/property.h b/include/linux/property.h
index ac8a1ebc4c1b..e77f08f49c48 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -109,6 +109,8 @@ struct fwnode_handle *device_get_named_child_node(struct device *dev,
struct fwnode_handle *fwnode_handle_get(struct fwnode_handle *fwnode);
void fwnode_handle_put(struct fwnode_handle *fwnode);

+int fwnode_get_name(const struct fwnode_handle *fwnode, char *name, size_t len);
+
int fwnode_irq_get(struct fwnode_handle *fwnode, unsigned int index);

unsigned int device_get_child_node_count(struct device *dev);
--
2.19.2