Re: [PATCH v2 2/4] dt-bindings: remoteproc: Add compatibility for TEE support

Hello Rob,

On 1/30/24 18:51, Rob Herring wrote:

On Thu, Jan 18, 2024 at 11:04:31AM +0100, Arnaud Pouliquen wrote:

...

The "st,stm32mp1-m4-tee" compatible is utilized in a system configuration where the Cortex-M4 firmware is loaded by the Trusted execution Environment (TEE). For instance, this compatible is used in both the Linux and OP-TEE device-tree:

• In OP-TEE, a node is defined in the device tree with the st,stm32mp1-m4-tee to support signed remoteproc firmware. Based on DT properties, OP-TEE authenticates, loads, starts, and stops the firmware.
• On Linux, when the compatibility is set, the Cortex-M resets should not be declared in the device tree.

Signed-off-by: Arnaud Pouliquen arnaud.pouliquen@foss.st.com

V1 to V2 updates

• update "st,stm32mp1-m4" compatible description to generalize
• remove the 'reset-names' requirement in one conditional branch, as the property is already part of the condition test.

---

.../bindings/remoteproc/st,stm32-rproc.yaml | 52 +++++++++++++++---- 1 file changed, 43 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml index 370af61d8f28..6af821b15736 100644 --- a/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml +++ b/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml @@ -16,7 +16,12 @@ maintainers: properties: compatible:

• const: st,stm32mp1-m4

• enum:

•  - st,stm32mp1-m4
  

•  - st,stm32mp1-m4-tee
  

• description:

•  Use "st,stm32mp1-m4" for the Cortex-M4 coprocessor management by non-secure context
  

•  Use "st,stm32mp1-m4-tee" for the Cortex-M4 coprocessor management by secure context
  

reg: description: @@ -142,21 +147,40 @@ properties: required:

• compatible
• reg
• • resets

allOf:

• if: properties:

•    reset-names:
  

•      not:
  

•        contains:
  

•          const: hold_boot
  

•    compatible:
  

•      contains:
  

•        const: st,stm32mp1-m4
  

• then:

•  if:
  

•    properties:
  

•      reset-names:
  

•        not:
  

•          contains:
  

•            const: hold_boot
  

Note that this is true when 'reset-names' is not present. If that is not desired, then you need 'required: [reset-names]'. Not really a new issue though.

Yes that corresponds to my expectation, for compatibility with legacy DT. If the hold_boot reset was not used, reset-names was not mandatory I will add the 'required: [reset-names]' in the else

Thanks, Arnaud

...

•  then:
  

•    required:
  

•      - st,syscfg-holdboot
  

•      - resets
  

•  else:
  

•    properties:
  

•      st,syscfg-holdboot: false
  

•    required:
  

•      - resets
  

'resets' is always required within the outer 'then' schema, so you can move this up a level.

...

• • if:

•  properties:
  

•    compatible:
  

•      contains:
  

•        const: st,stm32mp1-m4-tee
  

  then:

•  required:
  

•    - st,syscfg-holdboot
  

• else: properties: st,syscfg-holdboot: false

•    reset-names: false
  

•    resets: false
  

additionalProperties: false @@ -188,5 +212,15 @@ examples: st,syscfg-rsc-tbl = <&tamp 0x144 0xFFFFFFFF>; st,syscfg-m4-state = <&tamp 0x148 0xFFFFFFFF>; };

• • |
• #include <dt-bindings/reset/stm32mp1-resets.h>
• m4@10000000 {

•  compatible = "st,stm32mp1-m4-tee";
  

•  reg = <0x10000000 0x40000>,
  

•        <0x30000000 0x40000>,
  

•        <0x38000000 0x10000>;
  

•  st,syscfg-rsc-tbl = <&tamp 0x144 0xFFFFFFFF>;
  

•  st,syscfg-m4-state = <&tamp 0x148 0xFFFFFFFF>;
  

• };

... -- 2.25.1