diff --git a/plat/st/stm32mp1/stm32mp1_dt.c b/plat/st/stm32mp1/stm32mp1_dt.c
new file mode 100644
index 0000000..6098759
--- /dev/null
+++ b/plat/st/stm32mp1/stm32mp1_dt.c
@@ -0,0 +1,153 @@
+/*
+ * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <debug.h>
+#include <libfdt.h>
+#include <platform_def.h>
+#include <stm32mp1_clk.h>
+#include <stm32mp1_clkfunc.h>
+#include <stm32mp1_dt.h>
+
+#define DT_GPIO_BANK_SHIFT	12
+#define DT_GPIO_BANK_MASK	0x1F000U
+#define DT_GPIO_PIN_SHIFT	8
+#define DT_GPIO_PIN_MASK	0xF00U
+#define DT_GPIO_MODE_MASK	0xFFU
+
+static int fdt_checked;
+
+static void *fdt = (void *)(uintptr_t)STM32MP1_DTB_BASE;
+
+/*******************************************************************************
+ * This function checks device tree file with its header.
+ * Returns 0 if success, and a negative value else.
+ ******************************************************************************/
+int dt_open_and_check(void)
+{
+	int ret = fdt_check_header(fdt);
+
+	if (ret == 0) {
+		fdt_checked = 1;
+	}
+
+	return ret;
+}
+
+/*******************************************************************************
+ * This function gets the address of the DT.
+ * If DT is OK, fdt_addr is filled with DT address.
+ * Returns 1 if success, 0 otherwise.
+ ******************************************************************************/
+int fdt_get_address(void **fdt_addr)
+{
+	if (fdt_checked == 1) {
+		*fdt_addr = fdt;
+	}
+
+	return fdt_checked;
+}
+
+/*******************************************************************************
+ * This function check the presence of a node (generic use of fdt library).
+ * Returns true if present, false else.
+ ******************************************************************************/
+bool fdt_check_node(int node)
+{
+	int len;
+	const char *cchar;
+
+	cchar = fdt_get_name(fdt, node, &len);
+
+	return (cchar != NULL) && (len >= 0);
+}
+
+/*******************************************************************************
+ * This function check the status of a node (generic use of fdt library).
+ * Returns true if "okay" or missing, false else.
+ ******************************************************************************/
+bool fdt_check_status(int node)
+{
+	int len;
+	const char *cchar;
+
+	cchar = fdt_getprop(fdt, node, "status", &len);
+	if (cchar == NULL) {
+		return true;
+	}
+
+	return strncmp(cchar, "okay", (size_t)len) == 0;
+}
+
+/*******************************************************************************
+ * This function check the secure-status of a node (generic use of fdt library).
+ * Returns true if "okay" or missing, false else.
+ ******************************************************************************/
+bool fdt_check_secure_status(int node)
+{
+	int len;
+	const char *cchar;
+
+	cchar = fdt_getprop(fdt, node, "secure-status", &len);
+	if (cchar == NULL) {
+		return true;
+	}
+
+	return strncmp(cchar, "okay", (size_t)len) == 0;
+}
+
+/*******************************************************************************
+ * This function reads a value of a node property (generic use of fdt
+ * library).
+ * Returns value if success, and a default value if property not found.
+ * Default value is passed as parameter.
+ ******************************************************************************/
+uint32_t fdt_read_uint32_default(int node, const char *prop_name,
+				 uint32_t dflt_value)
+{
+	const fdt32_t *cuint;
+	int lenp;
+
+	cuint = fdt_getprop(fdt, node, prop_name, &lenp);
+	if (cuint == NULL) {
+		return dflt_value;
+	}
+
+	return fdt32_to_cpu(*cuint);
+}
+
+/*******************************************************************************
+ * This function reads a series of parameters in a node property
+ * (generic use of fdt library).
+ * It reads the values inside the device tree, from property name and node.
+ * The number of parameters is also indicated as entry parameter.
+ * Returns 0 if success, and a negative value else.
+ * If success, values are stored at the third parameter address.
+ ******************************************************************************/
+int fdt_read_uint32_array(int node, const char *prop_name, uint32_t *array,
+			  uint32_t count)
+{
+	const fdt32_t *cuint;
+	int len;
+	uint32_t i;
+
+	cuint = fdt_getprop(fdt, node, prop_name, &len);
+	if (cuint == NULL) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	if ((uint32_t)len != (count * sizeof(uint32_t))) {
+		return -FDT_ERR_BADLAYOUT;
+	}
+
+	for (i = 0; i < ((uint32_t)len / sizeof(uint32_t)); i++) {
+		*array = fdt32_to_cpu(*cuint);
+		array++;
+		cuint++;
+	}
+
+	return 0;
+}