Re: [PATCH 5/6] gpio: mvebu: Add support for the Armada 7K/8K SoCs

Russell King - ARM Linux
2017-05-19T16:27:54Z

On Fri, May 19, 2017 at 05:24:10PM +0100, Russell King - ARM Linux wrote:
> On Fri, May 19, 2017 at 06:09:24PM +0200, Gregory CLEMENT wrote:
> > The Armada 7K and 8K SoCs use the same gpio controller as most of the
> > other mvebu SoCs. However, the main difference is that the GPIO
> > controller is part of a bigger system controller, and a syscon is used to
> > control the overall system controller. Therefore, the driver needs to be
> > adjusted to retrieve the regmap of the syscon to access registers, and
> > account for the fact that registers are located at a certain offset
> > within the regmap.
> >
> > This commit add the support of the syscon and introduce a new variant for
> > this case.
>
> Do you really need all this complexity of merging what seems to be two
> GPIO devices into one for DT purposes? The device itself appears to be
> two instances of the orion-gpio controller, one at 0x100 into the
> system controller and a second one at 0x140.
>
> If you instantiate two orion-gpio controllers, then you don't need to
> add the "mvchip->offset" stuff.
>
> I'd also say that it was the more correct approach, rather than adding
> more complexity to GPIO drivers to support whatever incarnation comes
> next.

Hmm, in fact, mvebu->offset always appears to be zero in this driver,
so I think the changes that add this member are entirely rendundant to
the function of this patch.

--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.