dt-bindings: nvmem: Add apple,efuses

Apple SoCs come with eFuses used to store factory-programmed data
such as calibration settings for the PCIe and Type-C PHY.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220429162701.2222-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/devicetree/bindings/nvmem/apple,efuses.yaml b/Documentation/devicetree/bindings/nvmem/apple,efuses.yaml
new file mode 100644 (file)
index 0000000..5ec8f2b
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/apple,efuses.yaml
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/nvmem/apple,efuses.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple SoC eFuse-based NVMEM
+
+description: |
+  Apple SoCs such as the M1 contain factory-programmed eFuses used to e.g. store
+  calibration data for the PCIe and the Type-C PHY or unique chip identifiers
+  such as the ECID.
+
+maintainers:
+  - Sven Peter <sven@svenpeter.dev>
+
+allOf:
+  - $ref: "nvmem.yaml#"
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - apple,t8103-efuses
+          - apple,t6000-efuses
+      - const: apple,efuses
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    efuse@3d2bc000 {
+        compatible = "apple,t8103-efuses", "apple,efuses";
+        reg = <0x3d2bc000 0x1000>;
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        ecid: efuse@500 {
+            reg = <0x500 0x8>;
+        };
+    };
+
+...