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authorMauro Carvalho Chehab <mchehab+huawei@kernel.org>2020-04-15 16:45:22 +0200
committerRob Herring <robh@kernel.org>2020-05-04 17:09:52 -0500
commit642e6e5ce03e5b02d658e87d6c21d881b1ce8f62 (patch)
tree0367f0da7d89483797d3af6522ad5acbf278be23 /Documentation
parent218e1b3d10f1face9f1684f713346072fea3d3ec (diff)
docs: dt: convert overlay-notes.txt to ReST format
- Add a SPDX header; - Adjust document title; - Some whitespace fixes and new line breaks; - Mark literal blocks as such; - Add it to devicetree/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/index.rst1
-rw-r--r--Documentation/devicetree/overlay-notes.rst (renamed from Documentation/devicetree/overlay-notes.txt)38
2 files changed, 22 insertions, 17 deletions
diff --git a/Documentation/devicetree/index.rst b/Documentation/devicetree/index.rst
index 8b78e2c25e5a..1c36bc19969b 100644
--- a/Documentation/devicetree/index.rst
+++ b/Documentation/devicetree/index.rst
@@ -12,3 +12,4 @@ Open Firmware and Device Tree
changesets
dynamic-resolution-notes
of_unittest
+ overlay-notes
diff --git a/Documentation/devicetree/overlay-notes.txt b/Documentation/devicetree/overlay-notes.rst
index b06ffcb8f0f8..c67cc676bbd2 100644
--- a/Documentation/devicetree/overlay-notes.txt
+++ b/Documentation/devicetree/overlay-notes.rst
@@ -1,5 +1,8 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=========================
Device Tree Overlay Notes
--------------------------
+=========================
This document describes the implementation of the in-kernel
device tree overlay functionality residing in drivers/of/overlay.c and is a
@@ -15,9 +18,9 @@ Since the kernel mainly deals with devices, any new device node that result
in an active device should have it created while if the device node is either
disabled or removed all together, the affected device should be deregistered.
-Lets take an example where we have a foo board with the following base tree:
+Lets take an example where we have a foo board with the following base tree::
----- foo.dts -----------------------------------------------------------------
+ ---- foo.dts ---------------------------------------------------------------
/* FOO platform */
/dts-v1/;
/ {
@@ -33,11 +36,12 @@ Lets take an example where we have a foo board with the following base tree:
peripheral1 { ... };
};
};
----- foo.dts -----------------------------------------------------------------
+ ---- foo.dts ---------------------------------------------------------------
The overlay bar.dts,
+::
----- bar.dts - overlay target location by label ------------------------------
+ ---- bar.dts - overlay target location by label ----------------------------
/dts-v1/;
/plugin/;
&ocp {
@@ -47,11 +51,11 @@ The overlay bar.dts,
... /* various properties and child nodes */
};
};
----- bar.dts -----------------------------------------------------------------
+ ---- bar.dts ---------------------------------------------------------------
-when loaded (and resolved as described in [1]) should result in foo+bar.dts
+when loaded (and resolved as described in [1]) should result in foo+bar.dts::
----- foo+bar.dts -------------------------------------------------------------
+ ---- foo+bar.dts -----------------------------------------------------------
/* FOO platform + bar peripheral */
/ {
compatible = "corp,foo";
@@ -72,7 +76,7 @@ when loaded (and resolved as described in [1]) should result in foo+bar.dts
};
};
};
----- foo+bar.dts -------------------------------------------------------------
+ ---- foo+bar.dts -----------------------------------------------------------
As a result of the overlay, a new device node (bar) has been created
so a bar platform device will be registered and if a matching device driver
@@ -84,9 +88,9 @@ in the base DT. In this case, the target path can be provided. The target
location by label syntax is preferred because the overlay can be applied to
any base DT containing the label, no matter where the label occurs in the DT.
-The above bar.dts example modified to use target path syntax is:
+The above bar.dts example modified to use target path syntax is::
----- bar.dts - overlay target location by explicit path ----------------------
+ ---- bar.dts - overlay target location by explicit path --------------------
/dts-v1/;
/plugin/;
&{/ocp} {
@@ -96,7 +100,7 @@ The above bar.dts example modified to use target path syntax is:
... /* various properties and child nodes */
}
};
----- bar.dts -----------------------------------------------------------------
+ ---- bar.dts ---------------------------------------------------------------
Overlay in-kernel API
@@ -104,12 +108,12 @@ Overlay in-kernel API
The API is quite easy to use.
-1. Call of_overlay_fdt_apply() to create and apply an overlay changeset. The
-return value is an error or a cookie identifying this overlay.
+1) Call of_overlay_fdt_apply() to create and apply an overlay changeset. The
+ return value is an error or a cookie identifying this overlay.
-2. Call of_overlay_remove() to remove and cleanup the overlay changeset
-previously created via the call to of_overlay_fdt_apply(). Removal of an
-overlay changeset that is stacked by another will not be permitted.
+2) Call of_overlay_remove() to remove and cleanup the overlay changeset
+ previously created via the call to of_overlay_fdt_apply(). Removal of an
+ overlay changeset that is stacked by another will not be permitted.
Finally, if you need to remove all overlays in one-go, just call
of_overlay_remove_all() which will remove every single one in the correct