diff mbox series

[2/7] dt-bindings: clock: exynos850: Add tzpc property

Message ID 20230308233822.31180-3-semen.protsenko@linaro.org (mailing list archive)
State New
Headers show
Series clk: samsung: Enable PM in Exynos850 clk driver | expand

Commit Message

Sam Protsenko March 8, 2023, 11:38 p.m. UTC
Exynos850 requires extra TZPC handling to keep CMU registers non-secure
(accessible from the kernel) after PM resume. It's done using a specific
SMC call to the EL3 monitor.

Describe "samsung,tzpc" property for Exynos850 clock controller which
allows one to specify the SMC call address for PD capable CMUs.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
---
 .../bindings/clock/samsung,exynos850-clock.yaml        | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Krzysztof Kozlowski March 10, 2023, 2:51 p.m. UTC | #1
On 09/03/2023 00:38, Sam Protsenko wrote:
> Exynos850 requires extra TZPC handling to keep CMU registers non-secure
> (accessible from the kernel) after PM resume. It's done using a specific
> SMC call to the EL3 monitor.
> 
> Describe "samsung,tzpc" property for Exynos850 clock controller which
> allows one to specify the SMC call address for PD capable CMUs.
> 
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> ---
>  .../bindings/clock/samsung,exynos850-clock.yaml        | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml b/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
> index cc1e9173b272..5098dce5caf6 100644
> --- a/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
> +++ b/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
> @@ -60,6 +60,16 @@ properties:
>    reg:
>      maxItems: 1
>  
> +  samsung,tzpc:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      The register address in corresponding Trust Zone Protection Control block
> +      for setting the CMU registers access to non-secure. If provided, it'll be
> +      used for issuing SMC calls to EL3 monitor during CMU's PM suspend and
> +      resume operations, ensuring CMU registers are unprotected after waking up.

Do not store register addresses of MMIO in some fields. If this is part
of clock MMIO, then it could be address space in reg. If it is not, you
cannot store someone's else address space here. If this is someone's
else address space, then you either need syscon or phandle to dedicated
device (something like qcom,scm or other secure monitor channel).

> +
> +      This property is optional.

Drop, It's already optional if not required.

Best regards,
Krzysztof
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml b/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
index cc1e9173b272..5098dce5caf6 100644
--- a/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
+++ b/Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
@@ -60,6 +60,16 @@  properties:
   reg:
     maxItems: 1
 
+  samsung,tzpc:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      The register address in corresponding Trust Zone Protection Control block
+      for setting the CMU registers access to non-secure. If provided, it'll be
+      used for issuing SMC calls to EL3 monitor during CMU's PM suspend and
+      resume operations, ensuring CMU registers are unprotected after waking up.
+
+      This property is optional.
+
 allOf:
   - if:
       properties: