Re: [PATCH] dt-bindings: mailbox: add Versal IPI bindings

[Tanmay Shah <tanmay.shah@amd.com>]

On 12/6/23 9:09 AM, Rob Herring wrote:
> On Wed, Nov 29, 2023 at 05:19:36PM -0800, Tanmay Shah wrote:
> > Add documentation for AMD-Xilinx Versal platform Inter Processor Interrupt
> > controller. These bindings are different from previous
> > xlnx,zynqmp-ipi-mailbox bindings and hence introduced in separate file.
> > However, same existing driver will be extended for devices that are based
> > on Versal bindings.
>
> Looks to me like the binding doc could be shared.

Hi Rob,

Thanks for reviews.

Next revision I will share bindings doc.

>
> > 
> > Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
> > ---
> >  .../mailbox/xlnx,versal-ipi-mailbox.yaml      | 174 ++++++++++++++++++
> >  1 file changed, 174 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/mailbox/xlnx,versal-ipi-mailbox.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/mailbox/xlnx,versal-ipi-mailbox.yaml b/Documentation/devicetree/bindings/mailbox/xlnx,versal-ipi-mailbox.yaml
> > new file mode 100644
> > index 000000000000..4408b59d392d
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mailbox/xlnx,versal-ipi-mailbox.yaml
> > @@ -0,0 +1,174 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/mailbox/xlnx,versal-ipi-mailbox.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Xilinx IPI(Inter Processor Interrupt) mailbox controller
> > +
> > +description: |
> > +  The Xilinx IPI(Inter Processor Interrupt) mailbox controller is to manage
> > +  messaging between two IPI agents. Each IPI agent owns registers used for
> > +  notification and buffers for message.
> > +
> > +               +-------------------------------------+
> > +               | Xilinx IPI Controller               |
> > +               +-------------------------------------+
> > +    +--------------------------------------------------+
> > +  TF-A                   |                     |
> > +                         |                     |
> > +                         |                     |
> > +    +--------------------------+               |
> > +                         |                     |
> > +                         |                     |
> > +    +--------------------------------------------------+
> > +              +------------------------------------------+
> > +              |  +----------------+   +----------------+ |
> > +  Hardware    |  |  IPI Agent     |   |  IPI Buffers   | |
> > +              |  |  Registers     |   |  (optional)    | |
> > +              |  |                |   |                | |
> > +              |  +----------------+   +----------------+ |
> > +              |                                          |
> > +              | Xilinx IPI Agent Block                   |
> > +              +------------------------------------------+
> > +
> > +maintainers:
> > +  - Shubhrajyoti Datta <shubhrajyoti.datta@amd.com>
> > +
> > +properties:
> > +  compatible:
> > +    const: xlnx,versal-ipi-mailbox
> > +
> > +  method:
> > +    description: |
> > +      The method of calling the PM-API firmware layer.
> > +      Permitted values are.
> > +      - "smc" : SMC
> > +      - "hvc" : HVC
>
> The schema already says this, no need to do so twice.

Ok I will remove from description.


>
> > +
> > +    $ref: /schemas/types.yaml#/definitions/string
> > +    enum:
> > +      - smc
> > +      - hvc
> > +    default: smc
> > +
> > +  '#address-cells':
> > +    const: 2
> > +
> > +  '#size-cells':
> > +    const: 2
> > +
> > +  reg:
> > +    minItems: 1
> > +    items:
> > +      - description: Host IPI agent control registers
> > +      - description: Host IPI agent optional message buffers
> > +
> > +  reg-names:
> > +    minItems: 1
> > +    items:
> > +      - const: ctrl
> > +      - const: msg
> > +
> > +  xlnx,ipi-id:
> > +    description: |
> > +      Remote Xilinx IPI agent ID of which the mailbox is connected to.
> > +    $ref: /schemas/types.yaml#/definitions/uint32
>
> Any value 0-2^32 is valid?

No there are some limit on what is valid IPI ID. I will put valid range.


>
> Place vendor properties last.
Ack.
>
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  ranges: true
> > +
> > +patternProperties:
> > +  '^mailbox@[0-9a-f]+$':
> > +    description: Internal ipi mailbox node
> > +    type: object
> > +
> > +    properties:
> > +
> > +      compatible:
> > +        const: xlnx,versal-ipi-dest-mailbox
> > +
> > +      xlnx,ipi-id:
> > +        description:
> > +          Remote Xilinx IPI agent ID of which the mailbox is connected to.
> > +        $ref: /schemas/types.yaml#/definitions/uint32
>
> Any value 0-2^32 is valid?

Here as well. I will put valid range.


>
> > +
> > +      '#mbox-cells':
> > +        const: 1
> > +        description:
> > +          It contains tx(0) or rx(1) channel IPI id number.
> > +
> > +      reg:
> > +        minItems: 1
> > +        items:
> > +          - description: Host IPI agent control registers
> > +          - description: Host IPI agent optional message buffers
>
> Same description as the parent? But the parent is not a mailbox (No 
> #mbox-cells)? 

Thanks. Yes it should say Remote IPI agent. I will fix this in next revision.


>
> > +
> > +      reg-names:
> > +        minItems: 1
> > +        items:
> > +          - const: ctrl
> > +          - const: msg
> > +
> > +    additionalProperties: false
> > +
> > +    required:
> > +      - compatible
> > +      - reg
> > +      - reg-names
> > +      - xlnx,ipi-id
> > +      - "#mbox-cells"
> > +
> > +additionalProperties: false
> > +
> > +required:
> > +  - compatible
> > +  - interrupts
> > +  - '#address-cells'
> > +  - '#size-cells'
> > +  - reg
> > +  - reg-names
> > +  - xlnx,ipi-id
>
> Same order as 'properties'.

Ack.


>
> > +
> > +examples:
> > +  - |
> > +    #include<dt-bindings/interrupt-controller/arm-gic.h>
> > +
> > +    amba {
>
> bus {

Ack.


> > +      #address-cells = <0x2>;
> > +      #size-cells = <0x2>;
> > +      zynqmp-mailbox@ff300000 {
> > +        compatible = "xlnx,versal-ipi-mailbox";
> > +        interrupts = <GIC_SPI 29 IRQ_TYPE_LEVEL_HIGH>;
> > +        xlnx,ipi-id = <0>;
> > +        #address-cells = <2>;
> > +        #size-cells = <2>;
> > +        reg = <0x0 0xff300000 0x0 0x1000>,
> > +              <0x0 0xff990000 0x0 0x1ff>;
> > +        reg-names = "ctrl", "msg";
> > +        ranges;
> > +
> > +        /* buffered IPI */
> > +        mailbox@ff340000 {
> > +          compatible = "xlnx,versal-ipi-dest-mailbox";
> > +          reg = <0x0 0xff340000 0x0 0x1000>,
> > +                <0x0 0xff990400 0x0 0x1ff>;
> > +          reg-names = "ctrl", "msg";
> > +          #mbox-cells = <1>;
> > +          xlnx,ipi-id = <4>;
> > +        };
> > +
> > +        /* bufferless IPI */
> > +        mailbox@ff370000 {
> > +          compatible = "xlnx,versal-ipi-dest-mailbox";
> > +          reg = <0x0 0xff370000 0x0 0x1000>;
> > +          reg-names = "ctrl";
> > +          #mbox-cells = <1>;
> > +          xlnx,ipi-id = <7>;
> > +        };
> > +      };
> > +    };
> > +
> > +...
> > 
> > base-commit: 2cc14f52aeb78ce3f29677c2de1f06c0e91471ab
> > -- 
> > 2.25.1
> >