Re: [PATCH v2 1/4] dt-bindings: firmware: qcom,scm: Add minidump SRAM property

[Mukesh Ojha]

On Wed, May 20, 2026 at 12:17:21PM +0200, Krzysztof Kozlowski wrote:
> On Tue, May 19, 2026 at 10:44:39PM +0530, Mukesh Ojha 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 a 'sram' property 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.
> > 
> > Signed-off-by: Mukesh Ojha <mukesh.ojha@xxxxxxxxxxxxxxxx>
> > ---
> >  .../devicetree/bindings/firmware/qcom,scm.yaml   | 16 ++++++++++++++++
> >  1 file changed, 16 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/firmware/qcom,scm.yaml b/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
> > index 25f62bacbc91..27422d00b8fc 100644
> > --- a/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
> > +++ b/Documentation/devicetree/bindings/firmware/qcom,scm.yaml
> > @@ -129,6 +129,13 @@ properties:
> >            - description: offset of the download mode control register
> >      description: TCSR hardware block
> >  
> > +  sram:
> > +    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
> > +
> >  allOf:
> >    # Clocks
> >    - if:
> > @@ -250,3 +257,12 @@ examples:
> >              clock-names = "core", "bus", "iface";
> >          };
> >      };
> > +
> > +  - |
> > +    firmware {
> > +        scm {
> > +            compatible = "qcom,scm-kaanapali", "qcom,scm";
> 
> Incomplete, missing interrupts.

Interrupt number comes from firmware and has not even been described
statically for SCM  for any SoC and so I am not sure to include it in
the example. Perhaps I took the wrong example here and should have taken
some pre-Gunyah Qualcomm SoC.

> 
> Best regards,
> Krzysztof
> 

-- 
-Mukesh Ojha