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

Sam Protsenko semen.protsenko at linaro.org
Wed Mar 8 15:38:17 PST 2023


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 at 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.
+
+      This property is optional.
+
 allOf:
   - if:
       properties:
-- 
2.39.2




More information about the linux-arm-kernel mailing list