tests: drivers: memc: test full SDRAM on a few stm32 boards

Add an overlay for some STM32 boards that embed an SDRAM connected
through FMC interface to better cover their accessibility. Despite
each SDRAM is a few MByte large test are not too long lasting:
- stm32f429i_disc1 .... 8MByte: <1s
- stm32f469i_disco ... 16MByte: <1.5s
- stm32f746g_disco .... 8MByte: <1s
- stm32f7508_dk ......  8MByte: not tested
- stm32f769i_disco ... 16MByte: ~2s
- stm32h745i_disco .... 8MByte: <0.2s
- stm32h747i_disco ... 32MByte: <0.6s
- stm32h750b_dk ....... 8Mbyte: <0.2s
- stm32h757i_eval .... 32MByte: not tested
- stm32h7b31i_dk ..... 16MByte: not tested

Adding these test ensures non-regression on SDRAM support.

Signed-off-by: Etienne Carriere <[email protected]>

Author: etienne-lms

tests/drivers/memc/ram/boards/stm32f429i_disc1.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Test the full SDRAM accesses. Disable LTDC to prevent conflicts */
+
+ram0: &sdram2 {};
+
+&ltdc {
+	status = "disabled";
+};

tests/drivers/memc/ram/boards/stm32f469i_disco.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Test the full SDRAM accesses. Discable LTDC to prevent conflicts */
+
+ram0: &sdram1 {};
+
+&ltdc {
+	status = "disabled";
+};

tests/drivers/memc/ram/boards/stm32f746g_disco.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Test the full SDRAM accesses. Discable LTDC to prevent conflicts */
+
+ram0: &sdram1 {};
+
+&ltdc {
+	status = "disabled";
+};

tests/drivers/memc/ram/boards/stm32f7508_dk.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Test the full SDRAM accesses. Disable LTDC node to prevent conflicts */
+
+ram0: &sdram1 {};
+
+&ltdc {
+	status = "disabled";
+};

tests/drivers/memc/ram/boards/stm32f769i_disco.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Test the full SDRAM accesses. Disable LTDC to prevent conflicts */
+
+ram0: &sdram1 {};
+
+&ltdc {
+	status = "disabled";
+};

tests/drivers/memc/ram/boards/stm32h745i_disco_stm32h745xx_m7.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Test the full SDRAM accesses. Disable LTDC to prevent conflicts */
+
+ram0: &sdram2 {};
+
+&ltdc {
+	status = "disabled";
+};

tests/drivers/memc/ram/boards/stm32h747i_disco_stm32h747xx_m7.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Test the full SDRAM accesses. Disable LTDC to prevent conflicts */
+
+ram0: &sdram2 {};
+
+&ltdc {
+	status = "disabled";
+};

tests/drivers/memc/ram/boards/stm32h750b_dk.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Test the full SDRAM accesses. Disable LTDC to prevent conflicts */
+
+ram0: &sdram2 {};
+
+&ltdc {
+	status = "disabled";
+};

tests/drivers/memc/ram/boards/stm32h757i_eval_stm32h757xx_m7.overlay

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Test the full SDRAM accesses. Disable ethernet nodes to prevent conflicts */
+
+ram0: &sdram2 {};
+
+&mac {
+	status = "disabled";
+};
+
+&mdio {
+	status = "disabled";
+};

tests/drivers/memc/ram/boards/stm32h7b31i_dk.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Test the full SDRAM accesses. Discable LTDC to prevent conflicts */
+
+ram0: &sdram2 {};
+
+&ltdc {
+	status = "disabled";
+};