Re: [PATCH 4/6] ARM: DTS: tegra: add the DFLL IP block to the T114 SoC file

[Paul Walmsley <pwalmsley-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>]

On 01/15/2014 11:50 AM, Gerhard Sittig wrote:
> On Mon, Jan 13, 2014 at 22:27 -0800, Paul Walmsley wrote:
>> On Thu, 19 Dec 2013, Stephen Warren wrote:
>>
>>> On 12/19/2013 05:49 AM, Paul Walmsley wrote:
>>>> Add basic DT bindings for the DFLL IP block for the NVIDIA Tegra114 SoC.
>>>> diff --git a/Documentation/devicetree/bindings/clock/nvidia,tegra114-dfll.txt b/Documentation/devicetree/bindings/clock/nvidia,tegra114-dfll.txt
>>>> +- clocks : Must contain an array of two-cell arrays, one per clock.
>>>> +           DFLL source clocks.  At minimum this should include the
>>>> +           reference clock source and the IP block's main clock
>>>> +           source.  Also it should contain the DFLL's I2C controller
>>>> +           clock source.  The format is <&clock-provider-phandle
>>>> +           clock-id>.
>>> Entries in "clocks" aren't two cells, they're a phandle plus as many
>>> cells as the node referenced by the phandle specifies.
>> It's worth noting that the clock binding documentation itself refers
>> to pairs:
>>
>> ----
>>
>> clocks:		List of phandle and clock specifier pairs, one pair
>> 		for each clock input to the device.  Note: if the
>> 		clock provider specifies '0' for #clock-cells, then
>> 		only the phandle portion of the pair will appear.
>>
>> ----
>>
>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/clock/clock-bindings.txt#n50
>>
>> But given the ambiguity of that documentation, I basically agree, so
>> have changed it to:
> Please note that there neither is an ambiguity nor a conflict
> here, and that you actually acknowledge what Stephen said:

I do not agree that the Documentation is unambiguous.

It is not correct to refer to a "pair" without a second item as a "pair."

> This is exactly what Stephen said:  A "clocks" item does not need
> to have two cells.  The pair of phandle and clock specifier don't
> necessarily translate into two cells, instead the number of cells
> depends on the clock provider.

I do agree with this, and have updated the documentation accordingly.


- Paul