Hello Krzysztof, On 1/26/24 12:03, Krzysztof Kozlowski wrote: > On 18/01/2024 11:04, 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@xxxxxxxxxxx> >> --- >> 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 > > The patch looks good to me, but I wonder about this choice of two > compatibles. > > Basically this is the same hardware with the same interface, but two > compatibles to differentiate a bit different firmware setup. We have > already such cases for Qualcomm [1] [2] and new ones will be coming. [3] > > I wonder whether this should be rather the same compatible with > additional property, e.g. "st,tee-control" or "remote-control". Yes the point is valid, I asked myself the question. I proposed a compatibility solution for one main reason. On the STM32MP15, if the firmware is loaded by Linux, no driver is probed in OP-TEE. But if the firmware is authenticated and loaded by OP-TEE, a Op-TEE driver is probed to manage memory access rights. The drawback of a property is that we would need to probe the OP-TEE driver for the STM32MP1 platform even if it is not used, just to check this property. Thanks, Arnaud > > [1] > https://elixir.bootlin.com/linux/v6.7.1/source/Documentation/devicetree/bindings/dma/qcom,bam-dma.yaml#L54 > > [2] > https://elixir.bootlin.com/linux/v6.7.1/source/Documentation/devicetree/bindings/net/qcom,ipa.yaml#L129 > (that's a bit different) > > [3] https://lore.kernel.org/linux-devicetree/20240124103623.GJ4906@thinkpad/ > > @Rob, > Any general guidance for this and Qualcomm? > > Best regards, > Krzysztof >
