[PATCH v4 03/11] dt-bindings: bus: document RIFSC

[Gatien Chevallier]

Document RIFSC (RIF security controller). RIFSC is a firewall controller
composed of different kinds of hardware resources.

Signed-off-by: Gatien Chevallier <gatien.chevallier@xxxxxxxxxxx>
---

Changes in V2: 
	- Corrected errors highlighted by Rob's robot
	- No longer define the maxItems for the "feature-domains"
	  property
	- Fix example (node name, status)
	- Declare "feature-domain-names" as an optional
	  property for child nodes
	- Fix description of "feature-domains" property

 .../bindings/bus/st,stm32mp25-rifsc.yaml      | 105 ++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/st,stm32mp25-rifsc.yaml

diff --git a/Documentation/devicetree/bindings/bus/st,stm32mp25-rifsc.yaml b/Documentation/devicetree/bindings/bus/st,stm32mp25-rifsc.yaml
new file mode 100644
index 000000000000..7aeb38296616
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/st,stm32mp25-rifsc.yaml
@@ -0,0 +1,105 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bus/st,stm32mp25-rifsc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: STM32 Resource isolation framework security controller
+
+maintainers:
+  - Gatien Chevallier <gatien.chevallier@xxxxxxxxxxx>
+
+description: |
+  Resource isolation framework (RIF) is a comprehensive set of hardware blocks
+  designed to enforce and manage isolation of STM32 hardware resources like
+  memory and peripherals.
+
+  The RIFSC (RIF security controller) is composed of three sets of registers,
+  each managing a specific set of hardware resources:
+    - RISC registers associated with RISUP logic (resource isolation device unit
+      for peripherals), assign all non-RIF aware peripherals to zero, one or
+      any security domains (secure, privilege, compartment).
+    - RIMC registers: associated with RIMU logic (resource isolation master
+      unit), assign all non RIF-aware bus master to one security domain by
+      setting secure, privileged and compartment information on the system bus.
+      Alternatively, the RISUP logic controlling the device port access to a
+      peripheral can assign target bus attributes to this peripheral master port
+      (supported attribute: CID).
+    - RISC registers associated with RISAL logic (resource isolation device unit
+      for address space - Lite version), assign address space subregions to one
+      security domains (secure, privilege, compartment).
+
+properties:
+  compatible:
+    contains:
+      const: st,stm32mp25-rifsc
+
+  reg:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 1
+
+  ranges: true
+
+  "#feature-domain-cells":
+    const: 1
+
+  feature-domain-controller: true
+
+patternProperties:
+  "^.*@[0-9a-f]+$":
+    description: Peripherals
+    type: object
+    properties:
+      feature-domains:
+        minItems: 1
+        description:
+          The phandle of the firewall controller of the peripheral and the
+          platform-specific firewall ID of the peripheral.
+
+      feature-domain-names:
+        minItems: 1
+
+    required:
+      - feature-domains
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+  - feature-domain-controller
+  - "#feature-domain-cells"
+  - ranges
+
+additionalProperties: false
+
+examples:
+  - |
+    // In this example, the usart2 device refers to rifsc as its domain
+    // controller.
+    // Access rights are verified before creating devices.
+
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    rifsc: bus@42080000 {
+        compatible = "st,stm32mp25-rifsc";
+        reg = <0x42080000 0x1000>;
+        #address-cells = <1>;
+        #size-cells = <1>;
+        feature-domain-controller;
+        #feature-domain-cells = <1>;
+        ranges;
+
+        usart2: serial@400e0000 {
+              compatible = "st,stm32h7-uart";
+              reg = <0x400e0000 0x400>;
+              interrupts = <GIC_SPI 115 IRQ_TYPE_LEVEL_HIGH>;
+              clocks = <&ck_flexgen_08>;
+              feature-domains = <&rifsc 32>;
+        };
+    };
-- 
2.25.1