Re: [PATCH v3 2/4] dt-bindings: can: fixed-transceiver: Add new CAN fixed transceiver bindings

[Sergei Shtylyov]

On 08/03/2017 12:48 PM, Franklin S Cooper Jr wrote:

> > > Add documentation to describe usage of the new fixed transceiver binding.
> > > This new binding is applicable for any CAN device therefore it exists as
> > > its own document.
> > >
> > > Signed-off-by: Franklin S Cooper Jr <fcooper@xxxxxx>
> > > ---
> > >    .../bindings/net/can/fixed-transceiver.txt         | 24
> > > ++++++++++++++++++++++
> > >    1 file changed, 24 insertions(+)
> > >    create mode 100644
> > > Documentation/devicetree/bindings/net/can/fixed-transceiver.txt
> > >
> > > diff --git
> > > a/Documentation/devicetree/bindings/net/can/fixed-transceiver.txt
> > > b/Documentation/devicetree/bindings/net/can/fixed-transceiver.txt
> > > new file mode 100644
> > > index 0000000..2f58838b
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/net/can/fixed-transceiver.txt
> > > @@ -0,0 +1,24 @@
> > > +Fixed transceiver Device Tree binding
> > > +------------------------------
> > > +
> > > +CAN transceiver typically limits the max speed in standard CAN and
> > > CAN FD
> > > +modes. Typically these limitations are static and the transceivers
> > > themselves
> > > +provide no way to detect this limitation at runtime. For this situation,
> > > +the "fixed-transceiver" node can be used.
> > > +
> > > +Required Properties:
> > > + max-bitrate:    a positive non 0 value that determines the max
> > > +        speed that CAN/CAN-FD can run. Any other value
> > > +        will be ignored.
> > > +
> > > +Examples:
> > > +
> > > +Based on Texas Instrument's TCAN1042HGV CAN Transceiver
> > > +
> > > +m_can0 {
> > > +    ....
> > > +    fixed-transceiver@0 {
> >
> >     The <unit-address> (after @) must only be specified if there's "reg"
>
> Sorry. Fixed this in my v2 and some how it came back. Will fix.
>
> > prop in the device node. Also, please name the node "can-transceiver@"
> > to be more in line with the DT spec. which requires generic node names.
>
> Its possible for future can transceivers drivers to be created. So I

   So what? Ah, you are using the node name to match in the CAN drivers...

> thought including fixed was important to indicate that this is a "dumb"
> transceiver similar to "fixed-link".

   I'm not sure the "fixed-link" MAC subnode assumed any transceiver at all...

> So would "fixed-can-transceiver" be
> ok or do you want to go with can-transceiver?

   I'm somewhat perplexed at this point...

MBR, Sergei