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

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Message-ID: <20191009140145.GE4254@piout.net>
Date:   Wed, 9 Oct 2019 16:01:45 +0200
From:   Alexandre Belloni <alexandre.belloni@...tlin.com>
To:     Kamel Bouhara <kamel.bouhara@...tlin.com>,
        Wolfram Sang <wsa@...-dreams.de>, linux-i2c@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Nicolas Ferre <nicolas.ferre@...rochip.com>,
        linux-arm-kernel@...ts.infradead.org, devicetree@...r.kernel.org,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>
Subject: Re: [PATCH 2/4] i2c: at91: implement i2c bus recovery

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?

> 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.

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com