Re: [PATCH 2/3] dt-bindings: mtd: Add a property to declare secure regions in Qcom NANDc

[Rob Herring]

On Sun, Mar 7, 2021 at 10:31 PM Manivannan Sadhasivam
<manivannan.sadhasivam@xxxxxxxxxx> wrote:
>
> On Fri, Mar 05, 2021 at 05:36:57PM -0600, Rob Herring wrote:
> > On Mon, Feb 22, 2021 at 05:32:58PM +0530, Manivannan Sadhasivam wrote:
> > > On a typical end product, a vendor may choose to secure some regions in
> > > the NAND memory which are supposed to stay intact between FW upgrades.
> > > The access to those regions will be blocked by a secure element like
> > > Trustzone. So the normal world software like Linux kernel should not
> > > touch these regions (including reading).
> > >
> > > So let's add a property for declaring such secure regions so that the
> > > driver can skip touching them.
> > >
> > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > > ---
> > >  Documentation/devicetree/bindings/mtd/qcom,nandc.yaml | 7 +++++++
> > >  1 file changed, 7 insertions(+)
> > >
> > > diff --git a/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml b/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml
> > > index 84ad7ff30121..7500e20da9c1 100644
> > > --- a/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml
> > > +++ b/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml
> > > @@ -48,6 +48,13 @@ patternProperties:
> > >          enum:
> > >            - 512
> > >
> > > +      qcom,secure-regions:
> > > +        $ref: /schemas/types.yaml#/definitions/uint32-array
> >
> > Don't you need 64-bit regions potentially? Though 4GB should be enough
> > for anyone.
> >
>
> Yes, given the size of current NAND based systems around, I thought 32 bit is
> enough.

Huh!? I was joking. 4GB is small nowadays. Make this 64-bit.

Rob