[PATCH v8 3/5] dt-bindings: remoteproc: Add compatibility for TEE support

Arnaud Pouliquen
2024-06-21T14:39:27Z

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
trees:
- In OP-TEE, a node is defined in the device tree with the
"st,stm32mp1-m4-tee" compatible to support signed remoteproc firmware.
Based on DT properties, the OP-TEE remoteproc framework is initiated to
expose a trusted application service to authenticate and load the remote
processor firmware provided by the Linux remoteproc framework, as well
as to start and stop the remote processor.
- In Linux, when the compatibility is set, the Cortex-M resets should not
be declared in the device tree. In such a configuration, the reset is
managed by the OP-TEE remoteproc driver and is no longer accessible from
the Linux kernel.

Associated with this new compatible, add the "st,proc-id" property to
identify the remote processor. This ID is used to define a unique ID,
common between Linux, U-Boot, and OP-TEE, to identify a coprocessor.
This ID will be used in requests to the OP-TEE remoteproc Trusted
Application to specify the remote processor.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
---
.../bindings/remoteproc/st,stm32-rproc.yaml | 58 ++++++++++++++++---
1 file changed, 50 insertions(+), 8 deletions(-)

diff --git a/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml
index 370af61d8f28..409123cd4667 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:
@@ -43,6 +48,10 @@ properties:
- description: The offset of the hold boot setting register
- description: The field mask of the hold boot

+ st,proc-id:
+ description: remote processor identifier
+ $ref: /schemas/types.yaml#/definitions/uint32
+
st,syscfg-tz:
deprecated: true
description:
@@ -142,21 +151,43 @@ 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
+ then:
+ required:
+ - st,syscfg-holdboot
+ else:
+ properties:
+ st,syscfg-holdboot: false
+ required:
+ - reset-names
required:
- - st,syscfg-holdboot
- else:
+ - resets
+
+ - if:
+ properties:
+ compatible:
+ contains:
+ const: st,stm32mp1-m4-tee
+ then:
properties:
st,syscfg-holdboot: false
+ reset-names: false
+ resets: false
+ required:
+ - st,proc-id

additionalProperties: false

@@ -188,5 +219,16 @@ 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,proc-id = <0>;
+ st,syscfg-rsc-tbl = <&tamp 0x144 0xFFFFFFFF>;
+ st,syscfg-m4-state = <&tamp 0x148 0xFFFFFFFF>;
+ };

...
--
2.25.1