[PATCH v2 3/6] doc: dt: Document the indirect overlay method.

From: Pantelis Antoniou
Date: Mon May 16 2016 - 16:18:36 EST


Add a description of the target index overlay method to the overlay
documention file.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
---
Documentation/devicetree/overlay-notes.txt | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/overlay-notes.txt b/Documentation/devicetree/overlay-notes.txt
index d418a6c..6995fc1 100644
--- a/Documentation/devicetree/overlay-notes.txt
+++ b/Documentation/devicetree/overlay-notes.txt
@@ -100,6 +100,10 @@ Finally, if you need to remove all overlays in one-go, just call
of_overlay_destroy_all() which will remove every single one in the correct
order.

+If your board has multiple slots/places where a single overlay can work
+and each slot is defined by a node, you can use the
+of_overlay_create_target_index() method to select the target.
+
Overlay DTS Format
------------------

@@ -110,9 +114,11 @@ The DTS of an overlay should have the following format:

fragment@0 { /* first child node */

- target=<phandle>; /* phandle target of the overlay */
+ /* phandle target of the overlay */
+ target=<phandle> [, <phandle>, ...];
or
- target-path="/path"; /* target path of the overlay */
+ /* target path of the overlay */
+ target-path="/path" [ , "/path", ...];

__overlay__ {
property-a; /* add property-a to the target */
@@ -131,3 +137,7 @@ Using the non-phandle based target method allows one to use a base DT which does
not contain a __symbols__ node, i.e. it was not compiled with the -@ option.
The __symbols__ node is only required for the target=<phandle> method, since it
contains the information required to map from a phandle to a tree location.
+
+Using a target index requires the use of a selector target on the call to
+of_overlay_create_target_index(). I.e. passing an index of 0 will select the
+target in the foo node, an index of 1 the bar node, etc.
--
1.7.12