Re: [PATCH RESEND v1 2/7] dt-bindings: can: mpfs: add missing required clock

On Thu, Dec 14, 2023 at 12:31:04PM +0100, Marc Kleine-Budde wrote:

On 13.12.2023 13:02:49, Conor Dooley wrote:

quoted

On Tue, Dec 12, 2023 at 09:49:41PM +0100, Marc Kleine-Budde wrote:

quoted

On 08.12.2023 17:12:24, Conor Dooley wrote:

quoted

From: Conor Dooley <conor.dooley@microchip.com>

The CAN controller on PolarFire SoC has an AHB peripheral clock _and_ a
CAN bus clock. The bus clock was omitted when the binding was written,
but is required for operation. Make up for lost time and add it.

Cautionary tale in adding bindings without having implemented a real
user for them perhaps.

Fixes: c878d518d7b6 ("dt-bindings: can: mpfs: document the mpfs CAN controller")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
 .../devicetree/bindings/net/can/microchip,mpfs-can.yaml    | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/can/microchip,mpfs-can.yaml b/Documentation/devicetree/bindings/net/can/microchip,mpfs-can.yaml
index 45aa3de7cf01..05f680f15b17 100644
--- a/Documentation/devicetree/bindings/net/can/microchip,mpfs-can.yaml
+++ b/Documentation/devicetree/bindings/net/can/microchip,mpfs-can.yaml

@@ -24,7 +24,10 @@ properties:
     maxItems: 1
 
   clocks:
-    maxItems: 1
+    maxItems: 2
+    items:
+      - description: AHB peripheral clock
+      - description: CAN bus clock

Do we we want to have a "clock-names" property, as we need the clock
rate of the CAN bus clock.

We should not need the clock-names property to be able to get both of
the clocks. clk_bulk_get_all() for example should be usable here.

ACK, but we need the clock rate of CAN clock. Does this binding check
that the CAN clock rate is the 2nd one?

The items list requires that the can clock be the second one, so drivers
etc can rely on that ordering.