Re: [PATCH v6 00/8] Renesas RZ/A1 pin and gpio controller

[Simon Horman]

On Wed, Jun 28, 2017 at 07:36:15PM +0200, Geert Uytterhoeven wrote:
> Hi Linus,
> 
> On Mon, Jun 26, 2017 at 10:45 AM, Geert Uytterhoeven
> <geert@xxxxxxxxxxxxxx> wrote:
> > On Thu, Jun 22, 2017 at 4:54 PM, Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> wrote:
> >>    this is 6th round of RZ/A1 pin controller patch series.
> >>
> >> Where did we stop: discussion from pin controller driver shifted toward two
> >> new generic pin configuration properties I added to the previous series
> >> (bi-directional and output-enable).
> >>
> >> After a really long discussion, we decided to go for handling internally all
> >> bi-directional use cases, making the generic property not a requirement for the
> >> series. Interestingly, we recently found out the number of pins actually
> >> requiring this flag is less (~half) than what reported by the processor manual,
> >> so we could have handled these internally from day one :(
> >>
> >> We also now manage internally pins requiring IO direction specified in software
> >> even when configured in alternate function mode (SWIO mode). Most of them are
> >> handled by the driver, some of them have to come from DTS as the user can freely
> >> select if they have to be inputs or outputs. For those pins, and after another
> >> discussion involving NXP developers, we decided to use input-enable and
> >> output-enable properties. I have just sent a patch to add output-enable to the
> >> generic pin configuration properties, but it is currently under discussion.
> >>
> >> However, none of the pins currently configured by mainline DTS require those
> >> properties to be specified, so I have dropped in this driver any dependency on
> >> output-enable property, and I'm using instead the already in place
> >> PIN_CONFIG_OUTPUT one. Once output-enable will eventually be accepted, we can
> >> update the driver to make use of it, but since there are no use cases for that
> >> at the moment, it makes not too much sense holding this series back for that.
> >>
> >> The total memory occupation we were so worried about of bi-directional and swio
> >> pin tables is now around 100 bytes, because of how the number of pins actually
> >> needing those flags has  reduced and because of how we have arranged the
> >> tables using bitfield structures (credits to Geert here).
> >>
> >> Having cleared out dependencies on new pin configuration properties and having
> >> made configuration flags a driver specific issue, I hope this version can be
> >> accepted and land in forthcoming pull request for Renesas PFC updates from
> >> Geert, pending some feedback from the linux-gpio community.
> >
> > If this is OK for you, I'd like to include the first 3 patches (plus a small
> > fix I received offline from Chris Brandt[*]) in my final pull request of
> > sh-pfc for v4.13 (which I have been postponing in anticipation of this driver).
> 
> And so I did. Queued in sh-pfc-for-v4.13, pull request sent.

I have applied up the dts changes on top of v4.13-rc1.