Hi Manivannan, Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> wrote on Tue, 23 Feb 2021 23:15:46 +0530: > Hi Miquel, > > On Tue, Feb 23, 2021 at 05:49:22PM +0100, Miquel Raynal wrote: > > Hi Manivannan, > > > > Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> wrote on Mon, > > 22 Feb 2021 17:32:58 +0530: > > > > > 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 > > > + 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? > > > > IIUC, if a property is not listed under "required" section then it is > optional. But I've added the quote here to just make it explicit. Absolutely, I was just wondering why you mentioned it here. I don't think it's useful, you can drop it. > > > 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. > > > > Hmm, sounds good to me. > > Thanks, > Mani > > > > + > > > allOf: > > > - $ref: "nand-controller.yaml#" > > > > > > > Thanks, > > Miquèl Thanks, Miquèl
