doc: Add binding document for fconf.
Complete the documentation with information on how to write a DTS for
fconf. This patch adds the bindings information for dynamic
configuration properties.
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>
Change-Id: Ic6d9f927df53bb87315c23ec5a8943d0c3258d45
diff --git a/docs/components/fconf/fconf_properties.rst b/docs/components/fconf/fconf_properties.rst
new file mode 100644
index 0000000..5c28a7a
--- /dev/null
+++ b/docs/components/fconf/fconf_properties.rst
@@ -0,0 +1,32 @@
+DTB binding for FCONF properties
+================================
+
+This document describes the device tree format of |FCONF| properties. These
+properties are not related to a specific platform and can be queried from
+common code.
+
+Dynamic configuration
+~~~~~~~~~~~~~~~~~~~~~
+
+The |FCONF| framework expects a *dtb-registry* node with the following field:
+
+- compatible [mandatory]
+ - value type: <string>
+ - Must be the string "fconf,dyn_cfg-dtb_registry".
+
+Then a list of subnodes representing a configuration |DTB|, which can be used
+by |FCONF|. Each subnode should be named according to the information it
+contains, and must be formed with the following fields:
+
+- load-address [mandatory]
+ - value type: <u64>
+ - Physical loading base address of the configuration.
+
+- max-size [mandatory]
+ - value type: <u32>
+ - Maximum size of the configuration.
+
+- id [mandatory]
+ - value type: <u32>
+ - Image ID of the configuration.
+
diff --git a/docs/components/fconf.rst b/docs/components/fconf/index.rst
similarity index 90%
rename from docs/components/fconf.rst
rename to docs/components/fconf/index.rst
index 7352ac3..0da56ec 100644
--- a/docs/components/fconf.rst
+++ b/docs/components/fconf/index.rst
@@ -81,6 +81,10 @@
This second level wrapper can be used to remap the ``FCONF_GET_PROPERTY()`` to
anything appropriate: structure, array, function, etc..
+To ensure a good interpretation of the properties, this documentation must
+explain how the properties are described for a specific backend. Refer to the
+:ref:`binding-document` section for more information and example.
+
Loading the property device tree
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -88,7 +92,7 @@
the properties' values. This must be done after the io layer is initialized, as
the |DTB| is stored on an external device (FIP).
-.. uml:: ../resources/diagrams/plantuml/fconf_bl1_load_config.puml
+.. uml:: ../../resources/diagrams/plantuml/fconf_bl1_load_config.puml
Populating the properties
~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -98,7 +102,7 @@
This function will call all the ``populate()`` callbacks which have been
registered with ``FCONF_REGISTER_POPULATOR()`` as described above.
-.. uml:: ../resources/diagrams/plantuml/fconf_bl2_populate.puml
+.. uml:: ../../resources/diagrams/plantuml/fconf_bl2_populate.puml
Namespace guidance
~~~~~~~~~~~~~~~~~~
@@ -129,3 +133,12 @@
Example:
- Arm io framework: arm.io_policies.bl31_id
+.. _binding-document:
+
+Properties binding information
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. toctree::
+ :maxdepth: 1
+
+ fconf_properties
diff --git a/docs/components/index.rst b/docs/components/index.rst
index 49986ca..e3ce614 100644
--- a/docs/components/index.rst
+++ b/docs/components/index.rst
@@ -10,7 +10,7 @@
arm-sip-service
debugfs-design
exception-handling
- fconf
+ fconf/index
firmware-update
platform-interrupt-controller-API
ras