Re: [PATCH v3] dt-bindings: net: can: c_can: convert to json-schema

[Dario Binacchi <dariobin@libero.it>]

Hi Rob,

> Il 31/07/2021 02:55 Rob Herring <robh+dt@kernel.org> ha scritto:
> 
>  
> On Fri, Jul 30, 2021 at 11:16 AM Dario Binacchi <dariobin@libero.it> wrote:
> >
> > Convert the Bosch C_CAN/D_CAN controller device tree binding
> > documentation to json-schema.
> >
> > Document missing properties.
> > Remove "ti,hwmods" as it is no longer used in TI dts.
> > Make "clocks" required as it is used in all dts.
> > Correct nodename in the example.
> >
> > Signed-off-by: Dario Binacchi <dariobin@libero.it>
> >
> > ---
> >
> > Changes in v3:
> >  - Add type (phandle-array) and size (maxItems: 2) to syscon-raminit
> >    property.
> >
> > Changes in v2:
> >  - Drop Documentation references.
> >
> >  .../bindings/net/can/bosch,c_can.yaml         | 85 +++++++++++++++++++
> >  .../devicetree/bindings/net/can/c_can.txt     | 65 --------------
> >  2 files changed, 85 insertions(+), 65 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/net/can/bosch,c_can.yaml
> >  delete mode 100644 Documentation/devicetree/bindings/net/can/c_can.txt
> >
> > diff --git a/Documentation/devicetree/bindings/net/can/bosch,c_can.yaml b/Documentation/devicetree/bindings/net/can/bosch,c_can.yaml
> > new file mode 100644
> > index 000000000000..416db97fbf9d
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/net/can/bosch,c_can.yaml
> > @@ -0,0 +1,85 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/net/can/bosch,c_can.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Bosch C_CAN/D_CAN controller Device Tree Bindings
> > +
> > +description: Bosch C_CAN/D_CAN controller for CAN bus
> > +
> > +maintainers:
> > +  - Dario Binacchi <dariobin@libero.it>
> > +
> > +allOf:
> > +  - $ref: can-controller.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
> > +      - enum:
> > +          - bosch,c_can
> > +          - bosch,d_can
> > +          - ti,dra7-d_can
> > +          - ti,am3352-d_can
> > +      - items:
> > +          - enum:
> > +              - ti,am4372-d_can
> > +          - const: ti,am3352-d_can
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  power-domains:
> > +    description: |
> > +      Should contain a phandle to a PM domain provider node and an args
> > +      specifier containing the DCAN device id value. It's mandatory for
> > +      Keystone 2 66AK2G SoCs only.
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    description: |
> > +      CAN functional clock phandle.
> > +    maxItems: 1
> > +
> > +  clock-names:
> > +    maxItems: 1
> > +
> > +  syscon-raminit:
> > +    description: |
> > +      Handle to system control region that contains the RAMINIT register,
> > +      register offset to the RAMINIT register and the CAN instance number (0
> > +      offset).
> > +    $ref: /schemas/types.yaml#/definitions/phandle-array
> > +    maxItems: 2
> 
> Sorry, I misread that and counted 2, not 3 items. But you should have
> run the checks.

Checks fail with both value 2 and value 3. Looking at other kernel bindings I think 
2 is correct. Looking through the kernel bindings I only saw examples of phandle-array 
type with maxItems: 1, which is not our case. For maxItems other than 1 I have not 
found examples. Is it possible that there is a bug in the checks on phandle-array 
with maxItems > 1?
Eventually I took inspiration from how the 'fsl,stop-mode' property is described in 
Documentation/devicetree/bindings/net/can/fsl,flexcan.yaml to describe 'syscon-raminit'.

> 
> > +
> > +required:
> > + - compatible
> > + - reg
> > + - interrupts
> > + - clocks
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    can@481d0000 {
> > +        compatible = "bosch,d_can";
> > +        reg = <0x481d0000 0x2000>;
> > +        interrupts = <55>;
> > +        interrupt-parent = <&intc>;
> > +        status = "disabled";
> 
> Don't show 'status' in examples. Why would one want an example disabled?

I'll remove it in version 4.

Thanks and regards,
Dario

> 
> > +    };
> > +  - |
> > +    can@0 {
> > +        compatible = "ti,am3352-d_can";
> > +        reg = <0x0 0x2000>;
> > +        clocks = <&dcan1_fck>;
> > +        clock-names = "fck";
> > +        syscon-raminit = <&scm_conf 0x644 1>;
> > +        interrupts = <55>;
> > +        status = "disabled";
> > +    };
> > diff --git a/Documentation/devicetree/bindings/net/can/c_can.txt b/Documentation/devicetree/bindings/net/can/c_can.txt
> > deleted file mode 100644
> > index 366479806acb..000000000000
> > --- a/Documentation/devicetree/bindings/net/can/c_can.txt
> > +++ /dev/null
> > @@ -1,65 +0,0 @@
> > -Bosch C_CAN/D_CAN controller Device Tree Bindings
> > --------------------------------------------------
> > -
> > -Required properties:
> > -- compatible           : Should be "bosch,c_can" for C_CAN controllers and
> > -                         "bosch,d_can" for D_CAN controllers.
> > -                         Can be "ti,dra7-d_can", "ti,am3352-d_can" or
> > -                         "ti,am4372-d_can".
> > -- reg                  : physical base address and size of the C_CAN/D_CAN
> > -                         registers map
> > -- interrupts           : property with a value describing the interrupt
> > -                         number
> > -
> > -The following are mandatory properties for DRA7x, AM33xx and AM43xx SoCs only:
> > -- ti,hwmods            : Must be "d_can<n>" or "c_can<n>", n being the
> > -                         instance number
> > -
> > -The following are mandatory properties for Keystone 2 66AK2G SoCs only:
> > -- power-domains                : Should contain a phandle to a PM domain provider node
> > -                         and an args specifier containing the DCAN device id
> > -                         value. This property is as per the binding,
> > -                         Documentation/devicetree/bindings/soc/ti/sci-pm-domain.yaml
> > -- clocks               : CAN functional clock phandle. This property is as per the
> > -                         binding,
> > -                         Documentation/devicetree/bindings/clock/ti,sci-clk.yaml
> > -
> > -Optional properties:
> > -- syscon-raminit       : Handle to system control region that contains the
> > -                         RAMINIT register, register offset to the RAMINIT
> > -                         register and the CAN instance number (0 offset).
> > -
> > -Note: "ti,hwmods" field is used to fetch the base address and irq
> > -resources from TI, omap hwmod data base during device registration.
> > -Future plan is to migrate hwmod data base contents into device tree
> > -blob so that, all the required data will be used from device tree dts
> > -file.
> > -
> > -Example:
> > -
> > -Step1: SoC common .dtsi file
> > -
> > -       dcan1: d_can@481d0000 {
> > -               compatible = "bosch,d_can";
> > -               reg = <0x481d0000 0x2000>;
> > -               interrupts = <55>;
> > -               interrupt-parent = <&intc>;
> > -               status = "disabled";
> > -       };
> > -
> > -(or)
> > -
> > -       dcan1: d_can@481d0000 {
> > -               compatible = "bosch,d_can";
> > -               ti,hwmods = "d_can1";
> > -               reg = <0x481d0000 0x2000>;
> > -               interrupts = <55>;
> > -               interrupt-parent = <&intc>;
> > -               status = "disabled";
> > -       };
> > -
> > -Step 2: board specific .dts file
> > -
> > -       &dcan1 {
> > -               status = "okay";
> > -       };
> > --
> > 2.17.1
> >