RE: [PATCH 0/3] Renesas RZ PFC and GPIO driver

[Chris Brandt <Chris.Brandt@xxxxxxxxxxx>]

Hi Laurent,

On Monday, January 09, 2017, Laurent Pinchart wrote:
> From a user point of view, option A looks better to me. However, it has
> two
> drawbacks:
> 
> - Through deciding what pin groups we make available we create a DT ABI
> that will make it difficult to fix mistakes in case the groups are not
> fine-grained enough.
> 
> - The data tables in C code are large, and we end up compiling many of
> them in multi-platform kernel, significantly increasing the kernel size.
> 
> I would thus favour option B.

I'm going to have a good read through the pinctrl documentation in the kernel
and have a look at the pinctrl-single driver and see if I can come up with
something that looks like option B.

Also, there are lots of drivers in the pinctrl directory, so I'll have a look
at what other SoCs vendors are doing to see if there are any good ideas there.

I can tell you that some of the other Renesas SoCs in pinctrl/sh-pfc like sh7757
and sh7724 are also per pin function type parts and might have worked better
with an option B type driver.
NOTE: I'm not saying we update those old crusty parts, but rather the R-Car
      PFC might be more non-standard.

Regards,
Chris

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