Re: [v5,1/7] QE: Add IC, SI and SIRAM document to device tree bindings.

From: Scott Wood
Date: Mon May 16 2016 - 21:42:09 EST


On Tue, 2016-05-17 at 01:18 +0000, Qiang Zhao wrote:
> On Tue, May 17, 2016 at 07:22AM, Scott Wood wrote:
> > -----Original Message-----
> > From: Scott Wood [mailto:oss@xxxxxxxxxxxx]
> > Sent: Tuesday, May 17, 2016 7:22 AM
> > To: Qiang Zhao <qiang.zhao@xxxxxxx>
> > Cc: robh+dt@xxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; Xiaobo Xie <xiaobo.xie@xxxxxxx>; Yang-Leo Li
> > <leoyang.li@xxxxxxx>; linuxppc-dev@xxxxxxxxxxxxxxxx
> > Subject: Re: [v5,1/7] QE: Add IC, SI and SIRAM document to device tree
> > bindings.
> >
> > On Wed, Mar 09, 2016 at 09:21:28AM +0800, Zhao Qiang wrote:
> > > Add IC, SI and SIRAM document of QE to
> > > Documentation/devicetree/bindings/powerpc/fsl/cpm_qe/qe.txt
> > >
> > > Signed-off-by: Zhao Qiang <qiang.zhao@xxxxxxx>
> > > Acked-by: Rob Herring <robh@xxxxxxxxxx>
> > > ---
> > > changes for v2
> > > - Add interrupt-controller in Required properties
> > > - delete address-cells and size-cells for qe-si and qe-siram Changes
> > > for v3
> > > - Add SoC specific caompatible strings to qe-si and qe-siram Changes
> > > for v4
> > > - NA
> > > Changes for v5
> > > - NA
> > >
> > > .../devicetree/bindings/powerpc/fsl/cpm_qe/qe.txt | 50
> > > ++++++++++++++++++++++
> > > 1 file changed, 50 insertions(+)
> > > +* Serial Interface Block (SI)
> > > +
> > > +The SI manages the routing of eight TDM lines to the QE block serial
> > > +drivers , the MCC and the UCCs, for receive and transmit.
> > > +
> > > +Required properties:
> > > +- compatible : should be "fsl,t1040-qe-si".
> > > +- reg : Address range of SI register set.
> >
> > Is t1040 the only chip that has or will ever have this?
>
> There also be t1024 and ls1043 supporting si.
> I thought to add them when adding their device node.
> If you think it is better to add them now, I will modify.

The binding is saying that the compatible "should" be "fsl,t1040-qe-si"
regardless of whether it's actually a t1040. Instead say that compatible must
include "fsl,<chip>-qe-si" and give t1040 as an example. If you intend
"fsl,t1040-qe-si" to be something that other compatible chips list, in
addition to their own <chip> compatibles, then also say that explicitly.

-Scott