Re: [PATCH v5 1/2] dt-bindings: i2c: pca954x: Add timeout reset property
From: Krzysztof Kozlowski
Date: Mon Oct 21 2024 - 03:29:40 EST
On Sat, Oct 19, 2024 at 11:09:43AM +0000, Wojciech Siudy (Nokia) wrote:
> Hi!
>
> > If you have a reset GPIO for the mux, then why wouldn't just use it
> > on timeout?
>
> Because we cannot do that on every board. The reset GPIO is provided to
> ensure, that we have reset signal de-asserted during initialisation.
> You might have connected other devices to the same reset line so this
> must be a configurable option.
>
> > What happens if you timeout and don't have this property? Just
> give up?
>
> This would be the case just like before introducting this change. Some
> aplications might do other attempt, the bus driver can try recovery.
> Unfortunately common reset line for multiple chips is not a rare
> situation.
And Linux handles it well now. This is reset of the I2C devices
(children), not the controller, right? If so, then:
1. It's not a property of the controller,
2. Linux already handles it - switch to reset controller framework.
Best regards,
Krzysztof