On 03/17/2016 12:06 PM, Rob Herring wrote:

On Wed, Mar 09, 2016 at 06:08:49PM +0800, Yangbo Lu wrote:

quoted

Move guts devicetree doc to Documentation/devicetree/bindings/soc/fsl/
since it's used by not only PowerPC but also ARM. And add a specification
for 'little-endian' property.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
---
Changes for v2:
	- None
Changes for v3:
	- None
Changes for v4:
	- Added this patch
Changes for v5:
	- Modified the description for little-endian property
Changes for v6:
	- None
---
 Documentation/devicetree/bindings/{powerpc => soc}/fsl/guts.txt | 3 +++
 1 file changed, 3 insertions(+)
 rename Documentation/devicetree/bindings/{powerpc => soc}/fsl/guts.txt (91%)

diff --git a/Documentation/devicetree/bindings/powerpc/fsl/guts.txt b/Documentation/devicetree/bindings/soc/fsl/guts.txt
similarity index 91%
rename from Documentation/devicetree/bindings/powerpc/fsl/guts.txt
rename to Documentation/devicetree/bindings/soc/fsl/guts.txt
index b71b203..07adca9 100644
--- a/Documentation/devicetree/bindings/powerpc/fsl/guts.txt
+++ b/Documentation/devicetree/bindings/soc/fsl/guts.txt

@@ -25,6 +25,9 @@ Recommended properties:
  - fsl,liodn-bits : Indicates the number of defined bits in the LIODN
    registers, for those SOCs that have a PAMU device.
 
+ - little-endian : Indicates that the global utilities block is little
+   endian. The default is big endian.

The default is "the native endianness of the system". So absence on an 
ARM system would be LE.

No.  For this binding, the default is big-endian, because that's what
existed for this device before an endian property was added.

"endianness of the system" is not a well-defined concept.

This property is valid for any simple-bus device, 

Since when does simple-bus mean anything more than that the nodes
underneath it can be used without bus-specific knowledge?

so it isn't really required to document per device. You can, but 
your description had better match the documented behaviour.

Documented where?

In fact, Documentation/devicetree/bindings/common-properties.txt
explicitly says of the endian properties, "If a binding supports these
properties, then the binding should also specify the default behavior if
none of these properties are present."

-Scott