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

Rob Herring
2021-03-05T23:37:34Z

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@linaro.org>
> ---
> 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.

If more than one addr+size, then you need a matrix.

> + description:
> + Regions in the NAND memory which are protected using a secure element
> + like Trustzone. This property contains the start address and size of
> + the secure regions present (optional).
> +
> allOf:
> - $ref: "nand-controller.yaml#"
>
> --
> 2.25.1
>