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

On Fri, Feb 14, 2025 at 06:05:40AM +0100, Dimitri Fedrau wrote:

Am Thu, Feb 13, 2025 at 08:07:22PM +0000 schrieb Conor Dooley:

quoted

On Wed, Feb 12, 2025 at 08:52:04PM +0100, Dimitri Fedrau wrote:

quoted

Am Tue, Feb 11, 2025 at 04:38:48PM +0000 schrieb Conor Dooley:

quoted

On Tue, Feb 11, 2025 at 02:12:33PM +0100, Dimitri Fedrau via B4 Relay wrote:

quoted

From: Dimitri Fedrau <redacted>

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 <redacted>
---
 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

Acked-by: Conor Dooley <conor.dooley@microchip.com>

Thanks for the explanation,
Conor.