[PATCH 00/10] ARM, arm64: dts: renesas: Use R-Car GPIO Gen[123] fallback compat strings

On Tue, Aug 08, 2017 at 07:29:28PM +0900, Magnus Damm wrote:

Hi Simon,

On Tue, Aug 8, 2017 at 5:39 PM, Simon Horman [off-list ref] wrote:

quoted

Use newly added R-Car GPIO Gen 1, 2 and 3 fallback compat strings in place
of now deprecated non-generation specific R-Car GPIO fallback compat string
in the DT of Renesas ARM and arm64 based SoCs.

This should have no run-time effect as the driver matches against the
per-SoC compat string before considering the fallback compat string.

Thanks for your efforts.I have no issue with your series (apart from
the GPIO and SATA mistake), but at the same time I believe the GPIO
hardware itself is backwards compatible between various generations.

In the nitpick department I would like to point out that the level of
hardware difference between say R-Car Gen1 GPIO and R-Car Gen2 GPIO is
similar to say good old uarts like 8250 and 16450 hardware. Basically
a couple of registers were added to the hardware in a
backwards-compatible way if I recall correctly.

So if we are going to use "compatible" to point out if hardware is
compatible or not then I would do this instead:

Thanks for your feedback.

When the generation specific compat strings were recently
added the renesas,gpio-rcar compat string was marked as deprecated
as I was under the understanding that it was only compatibile with gen 1 SoCs.

It now seems that was not the best thing to do and renesas,gpio-rcar should
be re-instated as being a generic fallback for all R-Car versions supported
in upstream.

Do you concur?