dt-bindings: microchip-otpc: document Microchip OTPC

Document Microchip OTP controller.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220706100627.6534-2-srinivas.kandagatla@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/nvmem/microchip,sama7g5-otpc.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/nvmem/microchip,sama7g5-otpc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip SAMA7G5 OTP Controller (OTPC)
+
+maintainers:
+  - Claudiu Beznea <claudiu.beznea@microchip.com>
+
+description: |
+  OTP controller drives a NVMEM memory where system specific data
+  (e.g. calibration data for analog cells, hardware configuration
+  settings, chip identifiers) or user specific data could be stored.
+
+allOf:
+  - $ref: "nvmem.yaml#"
+
+properties:
+  compatible:
+    items:
+      - const: microchip,sama7g5-otpc
+      - const: syscon
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/nvmem/microchip,sama7g5-otpc.h>
+
+    otpc: efuse@e8c00000 {
+        compatible = "microchip,sama7g5-otpc", "syscon";
+        reg = <0xe8c00000 0xec>;
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        temperature_calib: calib@1 {
+            reg = <OTP_PKT(1) 76>;
+        };
+    };
+
+...

include/dt-bindings/nvmem/microchip,sama7g5-otpc.h

+/* SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause */
+
+#ifndef _DT_BINDINGS_NVMEM_MICROCHIP_OTPC_H
+#define _DT_BINDINGS_NVMEM_MICROCHIP_OTPC_H
+
+/*
+ * Need to have it as a multiple of 4 as NVMEM memory is registered with
+ * stride = 4.
+ */
+#define OTP_PKT(id)			((id) * 4)
+
+#endif