Re: [PATCH 1/4] arm64: dts: qcom: sc8280xp: rename i2c5 to i2c21

From: Johan Hovold
Date: Tue Dec 13 2022 - 10:42:53 EST


On Tue, Dec 13, 2022 at 04:39:54PM +0100, Johan Hovold wrote:
> On Tue, Dec 13, 2022 at 09:04:39PM +0530, Shazad Hussain wrote:
> > On 12/13/2022 8:58 PM, Johan Hovold wrote:

> > >> So qup2_i2c18 becomes qup2_i2c2. Would I use the flat naming scheme for
> > >> the alias like so?
> > >>
> > >> aliases {
> > >> i2c18 = &qup2_i2c2;
> > >> }
> > >
> > > Or perhaps the i2c controllers should use a zero-based index instead of
> > > being named after the serial engines (e.g. as we do for the console
> > > uart).
> > >
> > > How are they named in the schematics?
> >
> > We should use from 0 to N.
>
> With N being 23 after the number of serial engines, or the number of
> available i2c buses on a particular board minus one?

Looks like the more recent Qualcomm platforms use aliases that reflect
the engine number (i.e. 0 to 23) for i2c and spi.

Johan