[RFC PATCH 2/2] dt-bindings: arm: Add secure-resets binding description

From: Etienne Carriere
Date: Thu Apr 23 2020 - 02:49:11 EST


Describe how resets property can leverage secure- property prefix
for reset controller assigned to secure or non-secure world.

Signed-off-by: Etienne Carriere <etienne.carriere@xxxxxxxxxx>
---
.../devicetree/bindings/arm/secure.txt | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/secure.txt b/Documentation/devicetree/bindings/arm/secure.txt
index 9bc94921f2a6..f0aa6a5fb436 100644
--- a/Documentation/devicetree/bindings/arm/secure.txt
+++ b/Documentation/devicetree/bindings/arm/secure.txt
@@ -72,6 +72,24 @@ Valid Secure world properties
clocks = <&scmi_clk 2>; /* NS relies on SCMI resources */
secure-clocks= <&clk 5>; /* S accesses the SoC reset interfaces */

+- secure-resets : specifies the Phandle list secure world shall use
+ for the related reset controller(s) whereas property "resets" specifies
+ the reset controller Phandle list non-secure shall use. This
+ configuration can apply for example when a hardware reset controller can
+ only be accessed by secure world and this one opens a software service,
+ as a SCMI reset domain, for non-secure world to access the resource when
+ platform assigns the reset control to non-secure world, i.e.:
+
+ resets = <&scmi_rst 0>, <&scmi_rst 1>;
+ secure-resets = <&rst 5>, <&rst 7>;
+ reset-names = "int", "ext";
+
+ Such device description relaxes constraints on device tree modifications
+ when one, a user or a bootloader, needs to assign a resource to secure
+ or non-secure worlds. Indeed, this allows only "status" and "secure-status"
+ to be set while the rest of the device description in the node remains
+ unchanged.
+
The secure-chosen node
----------------------

--
2.17.1