RE: [PATCH 1/4] dt-bindings: firmware: secvio: Add device tree bindings

[Vabhav Sharma]

> -----Original Message-----
> From: Frank Li <frank.li@xxxxxxx>
> Sent: Thursday, May 9, 2024 8:37 AM
> To: Vabhav Sharma <vabhav.sharma@xxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>; Krzysztof Kozlowski
> <krzk+dt@xxxxxxxxxx>; Conor Dooley <conor+dt@xxxxxxxxxx>; Franck
> Lenormand <franck.lenormand@xxxxxxx>; Aisheng Dong
> <aisheng.dong@xxxxxxx>; Shawn Guo <shawnguo@xxxxxxxxxx>; Sascha
> Hauer <s.hauer@xxxxxxxxxxxxxx>; Pengutronix Kernel Team
> <kernel@xxxxxxxxxxxxxx>; Fabio Estevam <festevam@xxxxxxxxx>; Peng Fan
> <peng.fan@xxxxxxx>; devicetree@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; imx@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; Varun Sethi <V.Sethi@xxxxxxx>; Silvano Di Ninno
> <silvano.dininno@xxxxxxx>; Pankaj Gupta <pankaj.gupta@xxxxxxx>; Daniel
> Baluta <daniel.baluta@xxxxxxx>
> Subject: Re: [PATCH 1/4] dt-bindings: firmware: secvio: Add device tree
> bindings
> 
> On Thu, May 09, 2024 at 02:45:32AM +0200, Vabhav Sharma wrote:
> > Document the secvio device tree bindings.
> 
> reduntant sentence.
Ok, I am removing in v3.
> >
> > The tampers are security feature available on i.MX products and
> > managed by SNVS block.The tamper goal is to detect the variation
>                         ^^ space here
> 
> > of hardware or physical parameters, which can indicate an attack.
> >
> > The SNVS, which provides secure non-volatile storage, allows to detect
> > some hardware attacks against the SoC.They are connected
>                                                ^^ space here
> > to the security-violation ports, which send an alert when an
> > out-of-range value is detected.
> >
> > The "imx-secvio-sc" module is designed to report security violations
> > and tamper triggering via SCU firmware to the user.
> >
> > Add the imx-scu secvio sub node and secvio sub node description.
> >
> > Signed-off-by: Franck LENORMAND <franck.lenormand@xxxxxxx>
> > Signed-off-by: Vabhav Sharma <vabhav.sharma@xxxxxxx>
> > ---
> >  .../bindings/arm/freescale/fsl,scu-secvio.yaml     | 35
> ++++++++++++++++++++++
> >  .../devicetree/bindings/firmware/fsl,scu.yaml      | 10 +++++++
> >  2 files changed, 45 insertions(+)
> >
> > diff --git
> > a/Documentation/devicetree/bindings/arm/freescale/fsl,scu-secvio.yaml
> > b/Documentation/devicetree/bindings/arm/freescale/fsl,scu-secvio.yaml
> > new file mode 100644
> > index 000000000000..30dc1e21f903
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/arm/freescale/fsl,scu-secvio.y
> > +++ aml
> > @@ -0,0 +1,35 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) %YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/arm/freescale/fsl,scu-secvio.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: NXP i.MX Security Violation driver
> 
> Violation detect driver
Ok
> 
> > +
> > +maintainers:
> > +  - Franck LENORMAND <franck.lenormand@xxxxxxx>
> > +
> > +description: |
> 
> Needn't "|"
Ok
> 
> > +  Receive security violation from the SNVS via the SCU firmware.
> > + Allow to  register notifier for additional processing
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - fsl,imx-sc-secvio
> > +
> > +  nvmem:
> > +    maxItems: 1
> > +
> 
> any interrupt defined? how do you notify such violation event?
Yes, there is security violation interrupt bit in register map of SECVIO HW block with uses RPC call to notify/enable/disable this bit using RPC API exported through SCU firmware
> 
> > +required:
> > +  - compatible
> > +  - nvmem
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    secvio {
> > +        compatible = "fsl,imx-sc-secvio";
> > +        nvmem = <&ocotp>;
> > +    };
> > diff --git a/Documentation/devicetree/bindings/firmware/fsl,scu.yaml
> > b/Documentation/devicetree/bindings/firmware/fsl,scu.yaml
> > index 557e524786c2..b40e127fdc88 100644
> > --- a/Documentation/devicetree/bindings/firmware/fsl,scu.yaml
> > +++ b/Documentation/devicetree/bindings/firmware/fsl,scu.yaml
> > @@ -129,6 +129,11 @@ properties:
> >        RTC controller provided by the SCU
> >      $ref: /schemas/rtc/fsl,scu-rtc.yaml
> >
> > +  secvio:
> > +    description:
> > +      Receive security violation from the SNVS via the SCU firmware
> > +    $ref: /schemas/arm/freescale/fsl,scu-secvio.yaml
> > +
> >    thermal-sensor:
> >      description:
> >        Thermal sensor provided by the SCU @@ -197,6 +202,11 @@
> > examples:
> >                  compatible = "fsl,imx8qxp-sc-rtc";
> >              };
> >
> > +            secvio {
> > +                compatible = "fsl,imx-sc-secvio";
> > +                nvmem = <&ocotp>;
> > +            };
> > +
> >              keys {
> >                  compatible = "fsl,imx8qxp-sc-key", "fsl,imx-sc-key";
> >                  linux,keycodes = <KEY_POWER>;
> >
> > --
> > 2.25.1
> >