Re: [PATCH 1/2] dt-bindings: can: fsl,flexcan: add transceiver capabilities

[Dimitri Fedrau <dima.fedrau@gmail.com>]

Am Thu, Feb 13, 2025 at 08:07:22PM +0000 schrieb Conor Dooley:
> On Wed, Feb 12, 2025 at 08:52:04PM +0100, Dimitri Fedrau wrote:
> > Am Tue, Feb 11, 2025 at 04:38:48PM +0000 schrieb Conor Dooley:
> > > On Tue, Feb 11, 2025 at 02:12:33PM +0100, Dimitri Fedrau via B4 Relay wrote:
> > > > From: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
> > > > 
> > > > Currently the flexcan driver does not support adding PHYs. Add the
> > > > capability to ensure that the PHY is in operational state when the link
> > > > is set to an "up" state.
> > > > 
> > > > Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
> > > > ---
> > > >  Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml | 3 +++
> > > >  1 file changed, 3 insertions(+)
> > > > 
> > > > diff --git a/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml b/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
> > > > index 97dd1a7c5ed26bb7f1b2f78c326d91e2c299938a..397957569588a61111a313cf9107e29dacc9e667 100644
> > > > --- a/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
> > > > +++ b/Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml
> > > > @@ -70,6 +70,9 @@ properties:
> > > >    xceiver-supply:
> > > >      description: Regulator that powers the CAN transceiver.
> > > >  
> > > > +  phys:
> > > > +    maxItems: 1
> > > 
> > > Can all devices in this binding support external phy? Are all devices
> > > limited to a single external phy?
> > > 
> > As far as I know, these devices are controllers without integrated PHY.
> > So they need a single external PHY. Transceivers can be very simple like
> > xceiver-supply in the binding, but I want to use "ti,tcan1043" in 
> > drivers/phy/phy-can-transceiver.
> 
> I'm not quite following, do all of these devices need to have an
> external phy but the property did not exist until now? How did any of
> them work, if that's the case?

The property xceiver-supply is used to describe connected transceiver
which do only rely on corresponding regulator configuration.
For example here:
https://elixir.bootlin.com/linux/v6.14-rc2/source/arch/arm/boot/dts/nxp/imx/imx6qdl-sabreauto.dtsi#L105

But I want to enable support for these:
https://elixir.bootlin.com/linux/v6.14-rc2/source/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml

Best regards,
Dimitri Fedrau