Hi! > Thanks for the review. > > On Tue, Jan 03, 2017 at 02:38:54PM -0600, Rob Herring wrote: > > On Wed, Dec 28, 2016 at 07:30:36PM +0100, Pavel Machek wrote: > > > From: Sakari Ailus <[email protected]> > > > > > > In the vast majority of cases the bus type is known to the driver(s) > > > since a receiver or transmitter can only support a single one. There > > > are cases however where different options are possible. > > > > What cases specifically? > > The existing V4L2 OF support tries to figure out the bus type and parse the > bus parameters based on that. This does not scale too well as there are > multiple serial busses that share common properties. > > Some hardware also supports multiple types of busses on the same interfaces.
Ok, I'll include that in the changelog.
> > As in MIPI CSI2?
>
> Yeah, I guess it'd make sense to make this explicit.
Ok.
> > > should be the combined length of data-lanes and clock-lanes properties.
> > > - If the lane-polarities property is omitted, the value must be
> > > interpreted
> > > - as 0 (normal). This property is valid for serial busses only.
> >
> > Why is this removed?
>
> Must have been by mistake. :-)
Fixed.
> > > -
> > > +- clock-inv: Clock or strobe signal inversion.
> > > + Possible values: 0 -- not inverted; 1 -- inverted
> >
> > "invert" assumes I know what is normal and I do not. Define what is
> > "normal" and name the property the opposite of that. If normal is data
> > shifted on clock rising edge, then call the the property
> > "clock-shift-falling-edge" for example..
>
> The hardware documentation says this is the "strobe/clock inversion control
> signal". I'm not entirely sure whether this is just signal polarity (it's a
> differential signal) or inversion of an internal signal of the CCP2 block.
>
> It might make sense to make this a private property for the OMAP 3 ISP
> instead. If it's seen elsewhere, then think about it again. I doubt it
> would, as CCP2 is an old bus that's used on Nokia N9, N950 and N900.
>
> As strobe is included, I'd add that to the name. Say,
> "ti,clock-strobe-inv".
Hmm. N900 does not use inversion. Would it make sense to simply
hardcode it to "not-inverted" for now?
Device tree changes are PITA :-(.
Pavel
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