[PATCH v2 1/4] dt-bindings: power: reset: add PSCRR NVMEM recorder binding

[Faruque Ansari]

Add binding for the PSCRR NVMEM recorder. Records the power state
change reason into a small NVMEM cell, such as a PMIC SDAM byte or
RTC scratch register — so the cause survives a power cycle and can be
read back on the next boot.

Signed-off-by: Faruque Ansari <faruque.ansari@xxxxxxxxxxxxxxxx>
---
 .../bindings/power/reset/pscrr-nvmem.yaml          | 59 ++++++++++++++++++++++
 MAINTAINERS                                        |  1 +
 2 files changed, 60 insertions(+)

diff --git a/Documentation/devicetree/bindings/power/reset/pscrr-nvmem.yaml b/Documentation/devicetree/bindings/power/reset/pscrr-nvmem.yaml
new file mode 100644
index 000000000000..5334c923d644
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/reset/pscrr-nvmem.yaml
@@ -0,0 +1,59 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/reset/pscrr-nvmem.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NVMEM Power State Change Reason recorder
+
+maintainers:
+  - Faruque Ansari <faruque.ansari@xxxxxxxxxxxxxxxx>
+  - Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
+
+description:
+  An NVMEM-backed recorder for Power State Change Reasons (PSCRR). Persists
+  the reboot or shutdown cause into a small NVMEM cell, such as an RTC
+  scratch register, a PMIC SDAM (Scratch Data Access Memory) byte, or an
+  EEPROM — so the reason survives a power cycle and can be read back on the
+  next boot. The cell is referenced via the standard nvmem-cells consumer
+  binding.
+
+allOf:
+  - $ref: /schemas/nvmem/nvmem-consumer.yaml#
+
+properties:
+  compatible:
+    const: pscrr-nvmem
+
+  nvmem-cells:
+    maxItems: 1
+
+  nvmem-cell-names:
+    items:
+      - const: pscr
+
+required:
+  - compatible
+  - nvmem-cells
+  - nvmem-cell-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    nvmem-layout {
+        compatible = "fixed-layout";
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        reboot_reason_persist: reboot-reason-persist@49 {
+            reg = <0x49 0x1>;
+        };
+    };
+
+    reboot-reason {
+        compatible = "pscrr-nvmem";
+        nvmem-cells = <&reboot_reason_persist>;
+        nvmem-cell-names = "pscr";
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 19b9f6605d98..f329cd9d0491 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21693,6 +21693,7 @@ R:	Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
 L:	linux-pm@xxxxxxxxxxxxxxx
 S:	Maintained
 F:	Documentation/ABI/testing/sysfs-kernel-pscrr
+F:	Documentation/devicetree/bindings/power/reset/pscrr-nvmem.yaml
 F:	drivers/power/reset/pscrr/
 F:	include/linux/pscrr.h
 F:	tools/testing/selftests/pscrr/

-- 
2.34.1