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

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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

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