Re: [PATCH v2 3/4] dt-bindings: can: renesas,rcar-canfd: Document RZ/T2H and RZ/N2H SoCs

Hi Krzysztof,

Thank you for the review.

On Fri, Jan 2, 2026 at 11:20 AM Krzysztof Kozlowski [off-list ref] wrote:

On Tue, Dec 30, 2025 at 11:58:13AM +0000, Prabhakar wrote:

quoted

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Document the CAN-FD controller used on the RZ/T2H and RZ/N2H SoCs. The
CAN-FD IP is largely compatible with the R-Car Gen4 block, but differs
in that AFLPN and CFTML are different, there is no reset line for the IP,
and it only supports two channels.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
v1->v2:
- No changes made.
---
 .../bindings/net/can/renesas,rcar-canfd.yaml  | 26 ++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml b/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
index fb709cfd26d7..4a83e9e34d67 100644
--- a/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
+++ b/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml

@@ -50,6 +50,12 @@ properties:
               - renesas,r9a09g057-canfd     # RZ/V2H(P)
           - const: renesas,r9a09g047-canfd

+      - const: renesas,r9a09g077-canfd      # RZ/T2H

That's part of other enum with single compatibles.

There is no enum with single compatibles as of in next [0], there is
only one compatible `renesas,r9a09g047-canfd`. I can club this with
RZ/T2H one.

[0] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml?h=next-20260106

quoted

+
+      - items:
+          - const: renesas,r9a09g087-canfd  # RZ/N2H
+          - const: renesas,r9a09g077-canfd
+
   reg:
     maxItems: 1

@@ -179,7 +185,6 @@ required:
   - clocks
   - clock-names
   - power-domains
-  - resets
   - assigned-clocks
   - assigned-clock-rates
   - channel0

@@ -243,11 +248,30 @@ allOf:
           minItems: 2
           maxItems: 2

+  - if:
+      properties:
+        compatible:
+          contains:
+            const: renesas,r9a09g077-canfd
+    then:
+      properties:
+        interrupts:
+          maxItems: 8
+
+        interrupt-names:
+          maxItems: 8
+
+        resets: false
+    else:
+      required:
+        - resets

Why is this de-synced with reset-names? Properties are supposed to
behave the same way, not once requiring resets other time requiring
reset-names.

There are SoCs that have a single reset and others that require two
resets. For SoCs that require two resets, the reset-names property is
marked as required, while for SoCs with a single reset it is not.
Apart from the RZ/T2H SoC, all SoCs have either one or two resets.
This difference is why the properties became de-synced. Let me know if
this can be handled differently.

Cheers,
Prabhakar