Re: [PATCH 1/4] dt-bindings: firmware: qcom,scm: Add minidump SRAM property

[Rob Herring]

On Thu, May 7, 2026 at 3:07 AM Mukesh Ojha <mukesh.ojha@xxxxxxxxxxxxxxxx> wrote:
>
> On most Qualcomm SoCs where minidump is supported, a word in always-on
> SRAM is shared between the kernel and boot firmware. Before DDR is
> initialised on the warm reset following a crash, firmware reads this
> word to decide if minidump is enabled and collect a minidump and where
>  to deliver it (USB upload to a host, or save to local storage).
>
> Add 'sram' and 'sram-names' properties to the SCM binding to describe
> a region in always-on SRAM where the minidump download destination
> value could be written. Boot firmware reads it before DDR is initialised
> on a warm reset to decide where to store the minidump either to host
> PC or to on device storage.
>
> Most of the Qualcomm SoC supporting minidump supports this, added the
> kaanapali SoC for now.
>
> Suggested-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
> Signed-off-by: Mukesh Ojha <mukesh.ojha@xxxxxxxxxxxxxxxx>
> ---
>  .../bindings/firmware/qcom,scm.yaml           | 57 +++++++++++++++++++
>  1 file changed, 57 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/firmware/qcom,scm.yaml b/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
> index 7918d31f58b4..6813081fd74a 100644
> --- a/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
> +++ b/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
> @@ -127,6 +127,22 @@ properties:
>            - description: offset of the download mode control register
>      description: TCSR hardware block
>
> +  sram:
> +    $ref: /schemas/types.yaml#/definitions/phandle-array

Drop. This is a common property though we need to create a common definition.

> +    description:
> +      Phandle to a region in always-on SRAM used to store the download
> +      mode value for boot firmware to read before DDR is initialised on
> +      the next warm reset.
> +    maxItems: 1
> +
> +  sram-names:
> +    items:
> +      - const: minidump

You don't need -names with 1 entry and sram-names is not a common property.

> +
> +dependencies:
> +  sram: [ sram-names ]
> +  sram-names: [ sram ]
> +
>  allOf:
>    # Clocks
>    - if:
> @@ -229,6 +245,18 @@ allOf:
>        properties:
>          memory-region: false
>
> +  - if:
> +      not:
> +        properties:
> +          compatible:
> +            contains:
> +              enum:
> +                - qcom,scm-kaanapali
> +    then:
> +      properties:
> +        sram: false
> +        sram-names: false
> +
>  required:
>    - compatible
>
> @@ -247,3 +275,32 @@ examples:
>              clock-names = "core", "bus", "iface";
>          };
>      };
> +
> +  - |
> +    /* kaanapali — minidump SRAM */
> +    / {
> +        #address-cells = <2>;
> +        #size-cells = <2>;
> +
> +        sram@14680000 {
> +            compatible = "qcom,kaanapali-imem", "mmio-sram";
> +            reg = <0x0 0x14680000 0x0 0x1000>;
> +            ranges = <0x0 0x0 0x14680000 0x1000>;
> +            no-memory-wc;
> +            #address-cells = <1>;
> +            #size-cells = <1>;
> +
> +            minidump_config: minidump-config@1c {
> +                reg = <0x1c 0x4>;
> +            };
> +        };

You don't need providers in examples. Really, don't need a whole other
example for 1 added property.

> +
> +        firmware {
> +            scm {
> +                compatible = "qcom,scm-kaanapali", "qcom,scm";
> +                sram = <&minidump_config>;
> +                sram-names = "minidump";
> +                #reset-cells = <1>;
> +            };
> +        };
> +    };
> --
> 2.53.0
>