device property: Introduce firmware node type for platform data

Introduce data structures and code allowing "built-in" properties
to be associated with devices in such a way that they will be used
by the device_property_* API if no proper firmware node (neither DT
nor ACPI) is present for the given device.

Each property is to be represented by a property_entry structure.
An array of property_entry structures (terminated with a null
entry) can be pointed to by the properties field of struct
property_set that can be added as a firmware node to a struct
device using device_add_property_set().  That will cause the
device_property_* API to use that property_set as the source
of properties if the given device does not have a DT node or
an ACPI companion device object associated with it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 34 insertions, 0 deletions

diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index fc30b84b532a..0408545bce42 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -16,6 +16,7 @@ enum fwnode_type {
 	FWNODE_INVALID = 0,
 	FWNODE_OF,
 	FWNODE_ACPI,
+	FWNODE_PDATA,
 };
 
 struct fwnode_handle {
diff --git a/include/linux/property.h b/include/linux/property.h
index 31dfd3db35d6..de8bdf417a35 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -131,4 +131,37 @@ static inline int fwnode_property_read_u64(struct fwnode_handle *fwnode,
 	return fwnode_property_read_u64_array(fwnode, propname, val, 1);
 }
 
+/**
+ * struct property_entry - "Built-in" device property representation.
+ * @name: Name of the property.
+ * @type: Type of the property.
+ * @nval: Number of items of type @type making up the value.
+ * @value: Value of the property (an array of @nval items of type @type).
+ */
+struct property_entry {
+	const char *name;
+	enum dev_prop_type type;
+	size_t nval;
+	union {
+		void *raw_data;
+		u8 *u8_data;
+		u16 *u16_data;
+		u32 *u32_data;
+		u64 *u64_data;
+		const char **str;
+	} value;
+};
+
+/**
+ * struct property_set - Collection of "built-in" device properties.
+ * @fwnode: Handle to be pointed to by the fwnode field of struct device.
+ * @properties: Array of properties terminated with a null entry.
+ */
+struct property_set {
+	struct fwnode_handle fwnode;
+	struct property_entry *properties;
+};
+
+void device_add_property_set(struct device *dev, struct property_set *pset);
+
 #endif /* _LINUX_PROPERTY_H_ */