| Message ID | 20230410182058.8949-2-quic_nkela@quicinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Allow parameter in smc/hvc calls | expand |
On Mon, Apr 10, 2023 at 11:20:57AM -0700, Nikunj Kela wrote: > Currently, smc/hvc calls are made with smc-id only. The parameters are > all set to zeros. This patch defines two optional device tree bindings, > that can be used to pass parameters in smc/hvc calls. > Why 2 values ? > This is useful when multiple scmi instances are used with common smc-id. > I really would like to avoid this binding. Because of lack of standard SMC/HVC FID for SCMI we had to add this binding. Extending for newer use case like this in a vendor specific way is something I would like to avoid. > Signed-off-by: Nikunj Kela <quic_nkela@quicinc.com> > --- > .../devicetree/bindings/firmware/arm,scmi.yaml | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml > index 5824c43e9893..ecf76b763c8c 100644 > --- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml > +++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml > @@ -115,6 +115,23 @@ properties: > description: > SMC id required when using smc or hvc transports > > + arm,smc32-params: > + $ref: /schemas/types.yaml#/definitions/uint32-array > + description: > + An optional parameter list passed in smc32 or hvc32 calls > + default: 0 > + minItems: 1 > + maxItems: 6 > + > + arm,smc64-params: > + $ref: /schemas/types.yaml#/definitions/uint64-array > + description: > + An optional parameter list passed in smc64 or hvc64 calls. > + This is valid only on ARM64 machines. > + default: 0 > + minItems: 1 > + maxItems: 6 > + Even if we end up adding(which I would very much like to avoid), I don't see the need for 32 and 64 bit params like this. There must be ways to avoid that used by some property in some other binding(I will look for one if we choose this path)
On 4/11/2023 5:54 AM, Sudeep Holla wrote: > On Mon, Apr 10, 2023 at 11:20:57AM -0700, Nikunj Kela wrote: >> Currently, smc/hvc calls are made with smc-id only. The parameters are >> all set to zeros. This patch defines two optional device tree bindings, >> that can be used to pass parameters in smc/hvc calls. >> > Why 2 values ? I can do with one property if you prefer that. Its just I wanted to ensure that whosoever is setting the parameter list, is mindful of 32bit vs 64bit convention. If we use one property, do you propose to add a new property like width to specify if the parameter list is for 32bit vs 64bit? >> This is useful when multiple scmi instances are used with common smc-id. >> > I really would like to avoid this binding. Because of lack of standard > SMC/HVC FID for SCMI we had to add this binding. Extending for newer use > case like this in a vendor specific way is something I would like to avoid. If you have a solution to get rid of FID from DTB node, I will follow the same however until that happens, my view is that we put the parameters in dtb. > >> Signed-off-by: Nikunj Kela <quic_nkela@quicinc.com> >> --- >> .../devicetree/bindings/firmware/arm,scmi.yaml | 18 ++++++++++++++++++ >> 1 file changed, 18 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml >> index 5824c43e9893..ecf76b763c8c 100644 >> --- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml >> +++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml >> @@ -115,6 +115,23 @@ properties: >> description: >> SMC id required when using smc or hvc transports >> >> + arm,smc32-params: >> + $ref: /schemas/types.yaml#/definitions/uint32-array >> + description: >> + An optional parameter list passed in smc32 or hvc32 calls >> + default: 0 >> + minItems: 1 >> + maxItems: 6 >> + >> + arm,smc64-params: >> + $ref: /schemas/types.yaml#/definitions/uint64-array >> + description: >> + An optional parameter list passed in smc64 or hvc64 calls. >> + This is valid only on ARM64 machines. >> + default: 0 >> + minItems: 1 >> + maxItems: 6 >> + > Even if we end up adding(which I would very much like to avoid), I don't see > the need for 32 and 64 bit params like this. There must be ways to avoid that > used by some property in some other binding(I will look for one if we choose > this path) >
On 10/04/2023 20:20, Nikunj Kela wrote: > Currently, smc/hvc calls are made with smc-id only. The parameters are > all set to zeros. This patch defines two optional device tree bindings, > that can be used to pass parameters in smc/hvc calls. > > This is useful when multiple scmi instances are used with common smc-id. > > Signed-off-by: Nikunj Kela <quic_nkela@quicinc.com> Since you sent v2 before our discussion finished, let me answer here: this does not look like property for DT. Do not send new patches without giving reviewers chance to respond. Best regards, Krzysztof
On 4/11/2023 10:18 AM, Krzysztof Kozlowski wrote: > On 10/04/2023 20:20, Nikunj Kela wrote: >> Currently, smc/hvc calls are made with smc-id only. The parameters are >> all set to zeros. This patch defines two optional device tree bindings, >> that can be used to pass parameters in smc/hvc calls. >> >> This is useful when multiple scmi instances are used with common smc-id. >> >> Signed-off-by: Nikunj Kela <quic_nkela@quicinc.com> > Since you sent v2 before our discussion finished, let me answer here: > this does not look like property for DT. Do not send new patches without > giving reviewers chance to respond. Ok. My rationale on that is, if we allow smc-id which goes in r0/w0/x0 registers in smc/hvc call to be part of dtb, then we should allow parameters which go in r1/w1/x1 to r6/w6/x6 register to be part of dtb. If you have an alternative suggestion, I am all ears! > Best regards, > Krzysztof >
diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml index 5824c43e9893..ecf76b763c8c 100644 --- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml +++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml @@ -115,6 +115,23 @@ properties: description: SMC id required when using smc or hvc transports + arm,smc32-params: + $ref: /schemas/types.yaml#/definitions/uint32-array + description: + An optional parameter list passed in smc32 or hvc32 calls + default: 0 + minItems: 1 + maxItems: 6 + + arm,smc64-params: + $ref: /schemas/types.yaml#/definitions/uint64-array + description: + An optional parameter list passed in smc64 or hvc64 calls. + This is valid only on ARM64 machines. + default: 0 + minItems: 1 + maxItems: 6 + linaro,optee-channel-id: $ref: /schemas/types.yaml#/definitions/uint32 description: @@ -427,6 +444,7 @@ examples: compatible = "arm,scmi-smc"; shmem = <&cpu_scp_lpri0>, <&cpu_scp_lpri1>; arm,smc-id = <0xc3000001>; + arm,smc64-params = <0xcd974d6c 0x5ed97289>; #address-cells = <1>; #size-cells = <0>;
Currently, smc/hvc calls are made with smc-id only. The parameters are all set to zeros. This patch defines two optional device tree bindings, that can be used to pass parameters in smc/hvc calls. This is useful when multiple scmi instances are used with common smc-id. Signed-off-by: Nikunj Kela <quic_nkela@quicinc.com> --- .../devicetree/bindings/firmware/arm,scmi.yaml | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)