Re: [PATCH v2 1/5] dt-bindings: net: can: renesas,rcar-canfd: Document RZ/G2L SoC

[Philipp Zabel]

Hi Prabhakar,

On Tue, 2021-07-20 at 15:31 +0100, Lad, Prabhakar wrote:
> Hi Philipp,
> 
> Thank you for the review.
> 
> On Tue, Jul 20, 2021 at 11:22 AM Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> wrote:
> > Hi Lad,

Sorry I mixed up your name.

> > On Mon, 2021-07-19 at 15:38 +0100, Lad Prabhakar wrote:
> > > Add CANFD binding documentation for Renesas RZ/G2L SoC.
> > > 
> > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > > Reviewed-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > > ---
> > >  .../bindings/net/can/renesas,rcar-canfd.yaml  | 66 +++++++++++++++++--
> > >  1 file changed, 60 insertions(+), 6 deletions(-)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml b/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
> > > index 0b33ba9ccb47..4fb6dd370904 100644
> > > --- a/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
> > > +++ b/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
> > > @@ -30,13 +30,15 @@ properties:
> > >                - renesas,r8a77995-canfd     # R-Car D3
> > >            - const: renesas,rcar-gen3-canfd # R-Car Gen3 and RZ/G2
> > > 
> > > +      - items:
> > > +          - enum:
> > > +              - renesas,r9a07g044-canfd    # RZ/G2{L,LC}
> > > +          - const: renesas,rzg2l-canfd     # RZ/G2L family
> > > +
> > >    reg:
> > >      maxItems: 1
> > > 
> > > -  interrupts:
> > > -    items:
> > > -      - description: Channel interrupt
> > > -      - description: Global interrupt
> > > +  interrupts: true
> > > 
> > >    clocks:
> > >      maxItems: 3
> > > @@ -50,8 +52,7 @@ properties:
> > >    power-domains:
> > >      maxItems: 1
> > > 
> > > -  resets:
> > > -    maxItems: 1
> > > +  resets: true
> > > 
> > >    renesas,no-can-fd:
> > >      $ref: /schemas/types.yaml#/definitions/flag
> > > @@ -91,6 +92,59 @@ required:
> > >    - channel0
> > >    - channel1
> > > 
> > > +if:
> > > +  properties:
> > > +    compatible:
> > > +      contains:
> > > +        enum:
> > > +          - renesas,rzg2l-canfd
> > > +then:
> > > +  properties:
> > > +    interrupts:
> > > +      items:
> > > +        - description: CAN global error interrupt
> > > +        - description: CAN receive FIFO interrupt
> > > +        - description: CAN0 error interrupt
> > > +        - description: CAN0 transmit interrupt
> > > +        - description: CAN0 transmit/receive FIFO receive completion interrupt
> > > +        - description: CAN1 error interrupt
> > > +        - description: CAN1 transmit interrupt
> > > +        - description: CAN1 transmit/receive FIFO receive completion interrupt
> > > +
> > > +    interrupt-names:
> > > +      items:
> > > +        - const: g_error
> > > +        - const: g_rx_fifo
> > > +        - const: can0_error
> > > +        - const: can0_tx
> > > +        - const: can0_tx_rx_fifo_receive_completion
> > > +        - const: can1_error
> > > +        - const: can1_tx
> > > +        - const: can1_tx_rx_fifo_receive_completion
> > > +
> > > +    resets:
> > > +      items:
> > > +        - description: CANFD_RSTP_N
> > > +        - description: CANFD_RSTC_N
> > 
> > Do you know what the "P" and "C" stands for? It would be nice if the
> > description could tell us what the reset lines are used for.
> > 
> unfortunately the HW manual does not mention  anything about "P" and "C" :(

Yes, unfortunately this is all too common.

> > I would prefer if you used these names (or shortened versions, for
> > example "rstp_n", "rstc_n") as "reset-names" and let the driver
> > reference the resets by name instead of by index.
> > 
> OK will do that and maxItems:2 for resets.
> 
> @Geert, for R-Car Gen3 does "canfd_rst" (as it's a module reset)
> sounds good for reset-names? Or do you have any other suggestions?

I agree with Geert here. Assuming no second reset will be discovered for
R-Car Gen3 later, there is no need to invent a name.

regards
Philipp