Re: [PATCH 2/3] dt-bindings: mtd: Add a property to declare secure regions in Qcom NANDc
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: 2021-02-23 16:50:40
Also in:
linux-arm-msm, lkml
Hi Manivannan, Manivannan Sadhasivam [off-list ref] wrote on Mon, 22 Feb 2021 17:32:58 +0530:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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 + 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).
What does this "(optional)" means? If you mean the property is optional then it should be described accordingly in the yaml file, or am I missing something? I wonder if it wouldn't be better to make this a NAND chip node property. I don't think a qcom prefix is needed as potentially many other SoCs might have the same "feature". I'm fine adding support for it in the qcom driver only though.
+ allOf: - $ref: "nand-controller.yaml#"
Thanks, Miquèl