gpioiic FDT overlays for sun8i-h3

[Ian Lepore]

On Fri, 2019-11-29 at 15:09 +0100, Emmanuel Vadot wrote:
> On Fri, 29 Nov 2019 15:54:31 +0200
> Nick Kostirya <nikolay.kostirya at i11.co> wrote:
> 
> > From: Nick Kostirya <nikolay.kostirya at i11.co>
> > To: Milan Obuch <milan at obuch.sk>
> > Subject: Re: gpioiic FDT overlays for sun8i-h3
> > Date: Fri, 29 Nov 2019 15:53:05 +0200
> > X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; i386-portbld-freebsd12.0)
> > 
> > On Fri, 29 Nov 2019 14:43:16 +0100
> > Milan Obuch <milan at obuch.sk> wrote:
> > 
> > > On Fri, 29 Nov 2019 15:37:54 +0200
> > > Nick Kostirya via freebsd-arm <freebsd-arm at freebsd.org> wrote:
> > >    
> > > > On Thu, 28 Nov 2019 06:21:49 +0100
> > > > Emmanuel Vadot <manu at bidouilliste.com> wrote:
> > > >      
> > > > >   Try this but I haven't even compiled it :
> > > > > 
> > > > > /dts-v1/;
> > > > > /plugin/;
> > > > > 
> > > > > / {
> > > > >      compatible = "allwinner,sun8i-h3";
> > > > > };
> > > > > 
> > > > > &{/soc/pinctrl at 1c20800} {
> > > > >          gpioiic0 {
> > > > >              compatible    = "gpioiic";
> > > > >              scl = <0>; /*    GPIO pin 00 (PA0) */
> > > > >              sda = <2>; /*    GPIO pin 02 (PA2) */
> > > > > 
> > > > >      };
> > > > > };      
> > > > 
> > > > Maybe I must rebuild all u-boot with this overlay?
> > > > 
> > > > Because the overlay do not help when it is in /boot/dtb/overlays/ and
> > > > /boot/msdos/dtb/overlays/.
> > > >     
> > > 
> > > Did you add in /boot/loader.conf line like
> > > 
> > > fdt_overlays="gpioiic"  
> > 
> > Yes.
> > I have 
> > fdt_overlays="sun8i-h3-sid,sun8i-h3-ths,sun8i-h3-opp,sun8i-h3-gpio-iic0"
> > 
> > where sun8i-h3-gpio-iic0 if gpioiic overlay.
> > 
> > I see gpioiic in ofwdump -a output. 
> 
>  Which means that the overlays was applied.
>  I've spent a few hours yesterday to find how to use this module and
> the result is we can't. The reason is that the driver is at an higher
> bus pass number than the parent (gpiobus) so the driver isn't probed
> and is removed from the child list of gpiobus, meaning that it's never
> added later.
>   ian@ and I agreed that it the driver would need to be rewritten
> because of this and because you cannot use gpio from different banks as
> it needs to be a children of one gpio controller.
>  So the TLDR is : right now this driver is useless (at least on FDT
> system).

I am working on this, though.  I'm thinking we should have something
usable later today, or at worst by the end of the weekend if it turns
complicated.

-- Ian