From 15416c86b494cd861d9f60d5a1940cfbf3bcc7f1 Mon Sep 17 00:00:00 2001 From: Tom Rini Date: Fri, 31 Aug 2018 11:59:11 -0400 Subject: [PATCH] dm: Update README.txt to clarify device tree usage In the section about Device Trees add a paragraph at the end that clarifies how we decide of a tree is valid or not. We say that all bindings must either be in the specification (link provided) or in our device-tree-bindings directory. We say that most of these come from the Linux Kernel and as such some design decisions are made for us already, but that in most cases we wish to retain compatibility. Cc: Simon Glass Cc: Bin Meng Signed-off-by: Tom Rini Reviewed-by: Simon Glass --- doc/driver-model/README.txt | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/doc/driver-model/README.txt b/doc/driver-model/README.txt index d6fa5c4..e949ff6 100644 --- a/doc/driver-model/README.txt +++ b/doc/driver-model/README.txt @@ -449,6 +449,15 @@ The driver model tree is intended to mirror that of the device tree. The root driver is at device tree offset 0 (the root node, '/'), and its children are the children of the root node. +In order for a device tree to be valid, the content must be correct with +respect to either device tree specification +(https://www.devicetree.org/specifications/) or the device tree bindings that +are found in the doc/device-tree-bindings directory. When not U-Boot specific +the bindings in this directory tend to come from the Linux Kernel. As such +certain design decisions may have been made already for us in terms of how +specific devices are described and bound. In most circumstances we wish to +retain compatibility without additional changes being made to the device tree +source files. Declaring Uclasses ------------------