Re: [PATCH 2/4] i2c: at91: implement i2c bus recovery

From: Ludovic Desroches
Date: Thu Oct 10 2019 - 02:54:12 EST


On Wed, Oct 09, 2019 at 04:01:47PM +0200, Alexandre Belloni wrote:
>
> On 09/10/2019 15:55:00+0200, Ludovic Desroches wrote:
> > On Wed, Oct 02, 2019 at 04:46:56PM +0200, Kamel Bouhara wrote:
> > > External E-Mail
> > >
> > >
> > > Implement i2c bus recovery when slaves devices might hold SDA low.
> > > In this case re-assign SCL/SDA to gpios and issue 9 dummy clock pulses
> > > until the slave release SDA.
> > >
> >
> > Hi Kamel,
> >
> > Thanks for adding this new feature. As I see patches only for sama5d3 and
> > sama5d4, I assume it has not been tested with a sama5d2, isn't it?
> >
>
> I there a point having it on sama5d2 as the controller already supports
> this feature?
>

Right, I was focused on pinctrl and forget we have this feature
supported by the IP.

> > I doubt it works with a sama5d2 because of the pinctrl. I also wonder if it can
> > work if we add .strict = true to pinmux_ops which is something plan for the
> > future...
> >
>
> I don't see why it wouldn't work with strict as this is switching muxing
> properly instead of using the pins for two functions at the same time.
>

Not sure devm_gpiod_get won't fail with strict.

Ludovic