Re: [PATCH 3/3] dt-bindings: ddr: Add bindings for Samsung LPDDR3 memories

From: Rob Herring
Date: Fri Sep 13 2019 - 10:37:10 EST


On Fri, Sep 06, 2019 at 01:50:26PM +0200, Krzysztof Kozlowski wrote:
> On Fri, 6 Sep 2019 at 13:39, Lukasz Luba <l.luba@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > Hi Krzysztof,
> >
> > On 9/6/19 12:56 PM, Krzysztof Kozlowski wrote:
> > > On Fri, 6 Sep 2019 at 12:14, Lukasz Luba <l.luba@xxxxxxxxxxxxxxxxxxx> wrote:
> > >>
> > >> Add description of bindings for Samsung k3qf2f20db LPDDR3 memory.
> > >> Minor fixes in the old documentation.
> > >>
> > >> Signed-off-by: Lukasz Luba <l.luba@xxxxxxxxxxxxxxxxxxx>
> > >> ---
> > >> .../devicetree/bindings/ddr/lpddr3.txt | 29 +++++++++++++++++--
> > >> 1 file changed, 27 insertions(+), 2 deletions(-)
> > >>
> > >> diff --git a/Documentation/devicetree/bindings/ddr/lpddr3.txt b/Documentation/devicetree/bindings/ddr/lpddr3.txt
> > >> index 3b2485b84b3f..de0905239767 100644
> > >> --- a/Documentation/devicetree/bindings/ddr/lpddr3.txt
> > >> +++ b/Documentation/devicetree/bindings/ddr/lpddr3.txt
> > >> @@ -40,10 +40,34 @@ Child nodes:
> > >> a given speed-bin. Please see Documentation/devicetree/
> > >> bindings/ddr/lpddr3-timings.txt for more information on "lpddr3-timings"
> > >>
> > >> +Samsung K3QF2F20DB LPDDR3 memory
> > >> +------------------------------------------------------------
> > >> +
> > >> +This binding uses the LPDDR3 binding (described above)
> > >> +
> > >> +Required properties:
> > >> +- compatible: Should be:
> > >> + "samsung,K3QF2F20DB"
> > >> + followed by "jedec,lpddr3"
> > >> +- density : <u32> representing density in Mb (Mega bits)
> > >> +- io-width : <u32> representing bus width. Possible value 32
> > >> +- #address-cells: Must be set to 1
> > >> +- #size-cells: Must be set to 0
> > >
> > > If you decided to repeat all properties again, then it deserves its
> > > own bindings file. However I though about simpler solution - just
> > > document compatible. Exactly the same as AT24 or AT25 EEPROM bindings.
> > > There is not much benefit from copying all these properties.
> > OK, I see. I will add only 'compatible' and skip the rest then.
> > So the lpddr3.txt file will get this addition:
> >
> > +Samsung K3QF2F20DB LPDDR3 memory
> > +------------------------------------------------------------
> > +
> > +This binding uses the LPDDR3 binding (described above)
> > +
> > +Required properties:
> > +- compatible: Should be:
> > + "samsung,K3QF2F20DB"
> > + followed by "jedec,lpddr3"
> > +
> > +Optional properties:
> > +
> > +The optional properties are the same as in the LPDDR3 generic bindings and
> > +values should be taken from the data-sheet. Detailed bindings are described
> > +above.
> > +
> > +Child nodes:
> > +
> > +Detailed bindings are described in LPDDR3 generic bindings described above.
> > +
> >
> > Is it OK?
>
> To me it is still a lot of text just for one compatible and I can
> image more of such entries for other memories... However I do not mind
> and anyway, YAML will simplify it. If you're in doubt, wait for Rob's
> reply as this is his part.

We can't have multiple (top-level) schema in one file, so better to add
in where the existing compatible strings are.

Rob