[PATCH 3/8] doc: dt: Document the indirect overlay method.
From: Pantelis Antoniou
Date: Fri Jun 12 2015 - 15:57:21 EST
Add a description of the indirect overlay method to the overlay
documention file.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
---
Documentation/devicetree/overlay-notes.txt | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/Documentation/devicetree/overlay-notes.txt b/Documentation/devicetree/overlay-notes.txt
index d418a6c..dd595e6 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_indirect()
+method to select the target.
+
Overlay DTS Format
------------------
@@ -113,6 +117,11 @@ The DTS of an overlay should have the following format:
target=<phandle>; /* phandle target of the overlay */
or
target-path="/path"; /* target path of the overlay */
+ or
+ target-indirect { /* indirect target selector */
+ foo { target|target-path ... };
+ bar { .... };
+ };
__overlay__ {
property-a; /* add property-a to the target */
@@ -131,3 +140,7 @@ 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.
+
+The indirect target requires the use of a selector target on the call to
+of_overlay_create_indirect(). I.e. passing the "foo" id will select the target
+in the foo node, "bar" in bar node, etc.
--
1.7.12
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