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Date:   Tue, 30 Mar 2021 09:40:48 -0500
From:   Rob Herring <robh@kernel.org>
To:     nikitos.tr@gmail.com
Cc:     agross@kernel.org, bjorn.andersson@linaro.org,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] dt-bindings: soc: qcom: Add bindings for Qualcomm
 Memshare service
Message-ID: <20210330144048.GA264685@robh.at.kernel.org>
References: <20210319172321.22248-1-nikitos.tr@gmail.com>
 <20210319172321.22248-2-nikitos.tr@gmail.com>
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On Fri, Mar 19, 2021 at 10:23:20PM +0500, nikitos.tr@gmail.com wrote:
> From: Nikita Travkin <nikitos.tr@gmail.com>
> 
> Add DT bindings for memshare: QMI service that allocates
> memory per remote processor request.
> 
> Signed-off-by: Nikita Travkin <nikitos.tr@gmail.com>
> ---
>  .../bindings/soc/qcom/qcom,memshare.yaml      | 109 ++++++++++++++++++
>  include/dt-bindings/soc/qcom,memshare.h       |  10 ++
>  2 files changed, 119 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,memshare.yaml
>  create mode 100644 include/dt-bindings/soc/qcom,memshare.h
> 
> diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,memshare.yaml b/Documentation/devicetree/bindings/soc/qcom/qcom,memshare.yaml
> new file mode 100644
> index 000000000000..ebdf128b066c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,memshare.yaml
> @@ -0,0 +1,109 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/soc/qcom/qcom,memshare.yaml#"
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> +
> +title: Qualcomm QMI Shared Memory Service

How many shared memory interfaces does Qcom have...

> +
> +description: |
> +  This driver provides a QMI service that allows remote processors (like modem)
> +  to request additional memory. It is used for applications like GPS in modem.

If the memory region is defined in reserved-memory, how are you 
allocating additional memory? 

> +
> +maintainers:
> +  - Nikita Travkin <nikitos.tr@gmail.com>
> +
> +properties:
> +  compatible:
> +    const: qcom,memshare
> +
> +  qcom,legacy-client:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description: Phandle to a memshare client node used for legacy requests.
> +
> +  "#address-cells":
> +    const: 1
> +
> +  "#size-cells":
> +    const: 0
> +
> +patternProperties:
> +  "^.*@[0-9]+$":
> +    type: object
> +
> +    properties:
> +      reg:
> +        description: Proc-ID for clients in this node.

What's Proc-ID?

> +
> +      qcom,qrtr-node:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        description: Node from which the requests are expected.
> +
> +      "#address-cells":
> +        const: 1
> +
> +      "#size-cells":
> +        const: 0
> +
> +    patternProperties:
> +      "^.*@[0-9]+$":
> +        type: object
> +
> +        properties:
> +          reg:
> +            description: ID of this client.

How does one determine the ID?

> +
> +          memory-region:
> +            $ref: /schemas/types.yaml#/definitions/phandle
> +            description: |
> +              Reserved memory region that should be used for allocation.
> +
> +        required:
> +          - reg
> +
> +    required:
> +      - reg
> +      - qcom,qrtr-node
> +
> +required:
> +  - compatible
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/soc/qcom,memshare.h>
> +
> +    reserved-memory {
> +
> +      #address-cells = <2>;
> +      #size-cells = <2>;
> +
> +      gps_mem: gps@93c00000 {
> +        reg = <0x0 0x93c00000 0x0 0x200000>;
> +        no-map;

We support 'compatible' in reserved-memory nodes, can you simplify the 
binding and put everything in here?

> +      };
> +    };
> +
> +    memshare {
> +      compatible = "qcom,memshare";
> +      qcom,legacy-client = <&memshare_gps>;
> +
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      mpss@0 {
> +        reg = <MEMSHARE_PROC_MPSS_V01>;
> +        qcom,qrtr-node = <0>;
> +
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        memshare_gps: gps@0 {
> +          reg = <0>;
> +          memory-region = <&gps_mem>;
> +        };
> +      };
> +    };
> +
> +...
> diff --git a/include/dt-bindings/soc/qcom,memshare.h b/include/dt-bindings/soc/qcom,memshare.h
> new file mode 100644
> index 000000000000..4cef1ef75d09
> --- /dev/null
> +++ b/include/dt-bindings/soc/qcom,memshare.h
> @@ -0,0 +1,10 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef __DT_QCOM_MEMSHARE_H__
> +#define __DT_QCOM_MEMSHARE_H__
> +
> +#define MEMSHARE_PROC_MPSS_V01 0
> +#define MEMSHARE_PROC_ADSP_V01 1
> +#define MEMSHARE_PROC_WCNSS_V01 2
> +
> +#endif /* __DT_QCOM_MEMSHARE_H__ */
> -- 
> 2.27.0
>