Re: [PATCH v2] docs: dt-bindings: add DTS Coding Style document

From: Dragan Simic
Date: Wed Nov 22 2023 - 03:29:56 EST


On 2023-11-22 09:21, Krzysztof Kozlowski wrote:
On 22/11/2023 09:09, Chen-Yu Tsai wrote:
On Wed, Nov 22, 2023 at 4:05 PM Krzysztof Kozlowski
<krzysztof.kozlowski@xxxxxxxxxx> wrote:

On 21/11/2023 14:50, Rafał Miłecki wrote:
+Order of Properties in Device Node
+----------------------------------
+
+Following order of properties in device nodes is preferred:
+
+1. compatible
+2. reg
+3. ranges
+4. Standard/common properties (defined by common bindings, e.g. without
+ vendor-prefixes)
+5. Vendor-specific properties
+6. status (if applicable)
+7. Child nodes, where each node is preceded with a blank line
+
+The "status" property is by default "okay", thus it can be omitted.

I think it would really help to include position of #address-cells and
#size-cells here. In some files I saw them above "compatible" that seems
unintuitive. Some prefer putting them at end which I think makes sense
as they affect children nodes.

Whatever you choose it'd be just nice to have things consistent.

This is a standard/common property, thus it goes to (4) above.

It's probably a mix, but AFAIK a lot of the device trees in tree have
#*-cells after "status". In some cases they are added in the board
.dts files, not the chip/module .dtsi files.

Existing DTS is not a good example :)


+1 that it makes sense at the end as they affect child nodes.

I still insist that status must be the last, because:
1. Many SoC nodes have address/size cells but do not have any children
(I2C, SPI), so we put useless information at the end.
2. Status should be the final information to say whether the node is
ready or is not. I read the node, check properties and then look at the end:
a. Lack of status means it is ready.
b. status=disabled means device still needs board resources/customization

I agree with the "status" belonging to the very end, because it's both logical and much more readable. Also, "status" is expected to be modified in the dependent DT files, which makes it kind of volatile and even more deserving to be placed last.