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

[Mukesh Ojha]

On Fri, May 08, 2026 at 07:07:14AM -0500, Rob Herring wrote:
> 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.

Did you mean to just drop ref for now? And common definition could be followed later or
create one as part of the series.

> 
> > +    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.

Will drop it.

> > +
> > +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.

Sure, will drop it.

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

-- 
-Mukesh Ojha