tests: nvmem: api: Add test suite for NVMEM devicetree API

Add basic testing to validate devictree macros for the NVMEM subsystem.
Add testing with an EEPROM backend.

Signed-off-by: Pieter De Gendt <[email protected]>

Author: pdgendt

dts/bindings/test/vnd,nvmem-consumer.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2025 Basalte bv
+# SPDX-License-Identifier: Apache-2.0
+
+description: Test NVMEM consumer node
+
+compatible: "vnd,nvmem-consumer"
+
+include: [nvmem-consumer.yaml]

dts/bindings/test/vnd,nvmem-provider.yaml

@@ -0,0 +1,8 @@
+# Copyright (c) 2025 Basalte bv
+# SPDX-License-Identifier: Apache-2.0
+
+description: Test NVMEM provider node
+
+compatible: "vnd,nvmem-provider"
+
+include: [nvmem-provider.yaml]

tests/subsys/nvmem/api/CMakeLists.txt

@@ -0,0 +1,8 @@
+# Copyright (c) 2025 Basalte bv
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(nvmem_eeprom)
+
+target_sources(app PRIVATE src/main.c)

tests/subsys/nvmem/api/eeprom.overlay

@@ -0,0 +1,32 @@
+/**
+ * Copyright (c) 2025, Basalte bv
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	aliases {
+		nvmem0 = &eeprom0;
+	};
+
+	test_consumer0: test-consumer0 {
+		compatible = "vnd,nvmem-consumer";
+		nvmem-cells = <&cell0>, <&cell10>;
+		nvmem-cell-names = "cell0", "cell10";
+	};
+};
+
+&eeprom0 {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	cell0: cell@0 {
+		reg = <0x0 0x10>;
+		#nvmem-cell-cells = <0>;
+	};
+
+	cell10: cell@10 {
+		reg = <0x10 0x10>;
+		read-only;
+		#nvmem-cell-cells = <0>;
+	};
+};

tests/subsys/nvmem/api/prj.conf

@@ -0,0 +1,2 @@
+CONFIG_ZTEST=y
+CONFIG_NVMEM=y

tests/subsys/nvmem/api/src/main.c

@@ -0,0 +1,50 @@
+/**
+ * Copyright (c) 2025 Basalte bv
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/ztest.h>
+#include <zephyr/nvmem.h>
+
+#define consumer0 DT_NODELABEL(test_consumer0)
+#define nvmem0    DT_ALIAS(nvmem0)
+
+static const struct nvmem_cell cell0 = NVMEM_CELL_GET_BY_IDX(consumer0, 0);
+static const struct nvmem_cell cell10 = NVMEM_CELL_GET_BY_NAME(consumer0, cell10);
+
+ZTEST(nvmem_api, test_nvmem_api)
+{
+	uint8_t buf[0x10];
+	int ret;
+
+	zexpect_equal_ptr(cell0.dev, DEVICE_DT_GET(nvmem0));
+	zexpect_equal(cell0.offset, 0);
+	zexpect_equal(cell0.size, 0x10);
+	zexpect_false(cell0.read_only);
+
+	zexpect_equal_ptr(cell10.dev, DEVICE_DT_GET(nvmem0));
+	zexpect_equal(cell10.offset, 0x10);
+	zexpect_equal(cell10.size, 0x10);
+	zexpect_true(cell10.read_only);
+
+	for (size_t i = 0; i < sizeof(buf); ++i) {
+		buf[i] = 2 * i;
+	}
+
+	ret = nvmem_cell_write(&cell0, buf, 0, sizeof(buf));
+	zassert_ok(ret, "Failed to write NVMEM");
+
+	memset(buf, 0, sizeof(buf));
+
+	ret = nvmem_cell_read(&cell0, buf, 0, sizeof(buf));
+	zassert_ok(ret, "Failed to read NVMEM");
+
+	for (size_t i = 0; i < sizeof(buf); ++i) {
+		zexpect_equal(buf[i], 2 * i);
+	}
+
+	ret = nvmem_cell_write(&cell10, buf, 0, sizeof(buf));
+	zassert_equal(ret, -EROFS, "Expected read-only NVMEM");
+}
+
+ZTEST_SUITE(nvmem_api, NULL, NULL, NULL, NULL, NULL);

tests/subsys/nvmem/api/testcase.yaml

@@ -0,0 +1,13 @@
+common:
+  platform_allow:
+    - native_sim
+  integration_platforms:
+    - native_sim
+  tags:
+    - nvmem
+tests:
+  subsys.nvmem.eeprom:
+    extra_configs:
+      - CONFIG_EEPROM=y
+    extra_dtc_overlay_files:
+      - eeprom.overlay

tests/subsys/nvmem/devicetree/CMakeLists.txt

@@ -0,0 +1,8 @@
+# Copyright (c) 2025 Basalte bv
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(nvmem_devictree)
+
+target_sources(app PRIVATE src/main.c)

tests/subsys/nvmem/devicetree/app.overlay

@@ -0,0 +1,29 @@
+/**
+ * Copyright (c) 2025, Basalte bv
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	test_consumer0: test-consumer0 {
+		compatible = "vnd,nvmem-consumer";
+		nvmem-cells = <&cell0>, <&cell10>;
+		nvmem-cell-names = "cell0", "cell10";
+	};
+
+	test_provider0: test-provider0 {
+		compatible = "vnd,nvmem-provider";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		cell0: cell@0 {
+			reg = <0x0 0x10>;
+			#nvmem-cell-cells = <0>;
+		};
+
+		cell10: cell@10 {
+			reg = <0x10 0x10>;
+			read-only;
+			#nvmem-cell-cells = <0>;
+		};
+	};
+};

tests/subsys/nvmem/devicetree/prj.conf

@@ -0,0 +1,2 @@
+CONFIG_ZTEST=y
+CONFIG_NVMEM=y