diff --git a/drivers/st/clk/stm32mp1_clkfunc.c b/drivers/st/clk/stm32mp1_clkfunc.c
new file mode 100644
index 0000000..d4c69cb
--- /dev/null
+++ b/drivers/st/clk/stm32mp1_clkfunc.c
@@ -0,0 +1,365 @@
+/*
+ * Copyright (c) 2017-2018, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <dt-bindings/clock/stm32mp1-clksrc.h>
+#include <errno.h>
+#include <libfdt.h>
+#include <stm32mp1_clk.h>
+#include <stm32mp1_clkfunc.h>
+#include <stm32mp1_dt.h>
+
+#define DT_RCC_NODE_NAME	"rcc@50000000"
+#define DT_RCC_CLK_COMPAT	"st,stm32mp1-rcc"
+#define DT_RCC_COMPAT		"syscon"
+#define DT_STGEN_COMPAT		"st,stm32-stgen"
+#define DT_UART_COMPAT		"st,stm32h7-uart"
+#define DT_USART_COMPAT		"st,stm32h7-usart"
+
+const char *stm32mp_osc_node_label[NB_OSC] = {
+	[_LSI] = "clk-lsi",
+	[_LSE] = "clk-lse",
+	[_HSI] = "clk-hsi",
+	[_HSE] = "clk-hse",
+	[_CSI] = "clk-csi",
+	[_I2S_CKIN] = "i2s_ckin",
+	[_USB_PHY_48] = "ck_usbo_48m"
+};
+
+/*******************************************************************************
+ * This function reads the frequency of an oscillator from its name.
+ * It reads the value indicated inside the device tree.
+ * Returns 0 if success, and a negative value else.
+ * If success, value is stored in the second parameter.
+ ******************************************************************************/
+int fdt_osc_read_freq(const char *name, uint32_t *freq)
+{
+	int node, subnode;
+	void *fdt;
+
+	if (fdt_get_address(&fdt) == 0) {
+		return -ENOENT;
+	}
+
+	node = fdt_path_offset(fdt, "/clocks");
+	if (node < 0) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	fdt_for_each_subnode(subnode, fdt, node) {
+		const char *cchar;
+		int ret;
+
+		cchar = fdt_get_name(fdt, subnode, &ret);
+		if (cchar == NULL) {
+			return ret;
+		}
+
+		if (strncmp(cchar, name, (size_t)ret) == 0) {
+			const fdt32_t *cuint;
+
+			cuint = fdt_getprop(fdt, subnode, "clock-frequency",
+					    &ret);
+			if (cuint == NULL) {
+				return ret;
+			}
+
+			*freq = fdt32_to_cpu(*cuint);
+
+			return 0;
+		}
+	}
+
+	/* Oscillator not found, freq=0 */
+	*freq = 0;
+	return 0;
+}
+
+/*******************************************************************************
+ * This function checks the presence of an oscillator property from its id.
+ * The search is done inside the device tree.
+ * Returns true/false regarding search result.
+ ******************************************************************************/
+bool fdt_osc_read_bool(enum stm32mp_osc_id osc_id, const char *prop_name)
+{
+	int node, subnode;
+	void *fdt;
+
+	if (fdt_get_address(&fdt) == 0) {
+		return false;
+	}
+
+	if (osc_id >= NB_OSC) {
+		return false;
+	}
+
+	node = fdt_path_offset(fdt, "/clocks");
+	if (node < 0) {
+		return false;
+	}
+
+	fdt_for_each_subnode(subnode, fdt, node) {
+		const char *cchar;
+		int ret;
+
+		cchar = fdt_get_name(fdt, subnode, &ret);
+		if (cchar == NULL) {
+			return false;
+		}
+
+		if (strncmp(cchar, stm32mp_osc_node_label[osc_id],
+			    (size_t)ret) != 0) {
+			continue;
+		}
+
+		if (fdt_getprop(fdt, subnode, prop_name, NULL) != NULL) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/*******************************************************************************
+ * This function reads a value of a oscillator property from its id.
+ * Returns value if success, and a default value if property not found.
+ * Default value is passed as parameter.
+ ******************************************************************************/
+uint32_t fdt_osc_read_uint32_default(enum stm32mp_osc_id osc_id,
+				     const char *prop_name, uint32_t dflt_value)
+{
+	int node, subnode;
+	void *fdt;
+
+	if (fdt_get_address(&fdt) == 0) {
+		return dflt_value;
+	}
+
+	if (osc_id >= NB_OSC) {
+		return dflt_value;
+	}
+
+	node = fdt_path_offset(fdt, "/clocks");
+	if (node < 0) {
+		return dflt_value;
+	}
+
+	fdt_for_each_subnode(subnode, fdt, node) {
+		const char *cchar;
+		int ret;
+
+		cchar = fdt_get_name(fdt, subnode, &ret);
+		if (cchar == NULL) {
+			return dflt_value;
+		}
+
+		if (strncmp(cchar, stm32mp_osc_node_label[osc_id],
+			    (size_t)ret) != 0) {
+			continue;
+		}
+
+		return fdt_read_uint32_default(subnode, prop_name, dflt_value);
+	}
+
+	return dflt_value;
+}
+
+/*******************************************************************************
+ * This function reads the rcc base address.
+ * It reads the value indicated inside the device tree.
+ * Returns address if success, and 0 value else.
+ ******************************************************************************/
+uint32_t fdt_rcc_read_addr(void)
+{
+	int node, subnode;
+	void *fdt;
+
+	if (fdt_get_address(&fdt) == 0) {
+		return 0;
+	}
+
+	node = fdt_path_offset(fdt, "/soc");
+	if (node < 0) {
+		return 0;
+	}
+
+	fdt_for_each_subnode(subnode, fdt, node) {
+		const char *cchar;
+		int ret;
+
+		cchar = fdt_get_name(fdt, subnode, &ret);
+		if (cchar == NULL) {
+			return 0;
+		}
+
+		if (strncmp(cchar, DT_RCC_NODE_NAME, (size_t)ret) == 0) {
+			const fdt32_t *cuint;
+
+			cuint = fdt_getprop(fdt, subnode, "reg", NULL);
+			if (cuint == NULL) {
+				return 0;
+			}
+
+			return fdt32_to_cpu(*cuint);
+		}
+	}
+
+	return 0;
+}
+
+/*******************************************************************************
+ * This function reads a series of parameters in rcc-clk section.
+ * It reads the values indicated inside the device tree, from property name.
+ * 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 second parameter address.
+ ******************************************************************************/
+int fdt_rcc_read_uint32_array(const char *prop_name,
+			      uint32_t *array, uint32_t count)
+{
+	int node;
+	void *fdt;
+
+	if (fdt_get_address(&fdt) == 0) {
+		return -ENOENT;
+	}
+
+	node = fdt_node_offset_by_compatible(fdt, -1, DT_RCC_CLK_COMPAT);
+	if (node < 0) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	return fdt_read_uint32_array(node, prop_name, array, count);
+}
+
+/*******************************************************************************
+ * This function gets the subnode offset in rcc-clk section from its name.
+ * It reads the values indicated inside the device tree.
+ * Returns offset if success, and a negative value else.
+ ******************************************************************************/
+int fdt_rcc_subnode_offset(const char *name)
+{
+	int node, subnode;
+	void *fdt;
+
+	if (fdt_get_address(&fdt) == 0) {
+		return -ENOENT;
+	}
+
+	node = fdt_node_offset_by_compatible(fdt, -1, DT_RCC_CLK_COMPAT);
+	if (node < 0) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	subnode = fdt_subnode_offset(fdt, node, name);
+	if (subnode <= 0) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	return subnode;
+}
+
+/*******************************************************************************
+ * This function gets the pointer to a rcc-clk property from its name.
+ * It reads the values indicated inside the device tree.
+ * Length of the property is stored in the second parameter.
+ * Returns pointer if success, and NULL value else.
+ ******************************************************************************/
+const uint32_t *fdt_rcc_read_prop(const char *prop_name, int *lenp)
+{
+	const uint32_t *cuint;
+	int node, len;
+	void *fdt;
+
+	if (fdt_get_address(&fdt) == 0) {
+		return NULL;
+	}
+
+	node = fdt_node_offset_by_compatible(fdt, -1, DT_RCC_CLK_COMPAT);
+	if (node < 0) {
+		return NULL;
+	}
+
+	cuint = fdt_getprop(fdt, node, prop_name, &len);
+	if (cuint == NULL) {
+		return NULL;
+	}
+
+	*lenp = len;
+	return cuint;
+}
+
+/*******************************************************************************
+ * This function gets the secure status for rcc node.
+ * It reads secure-status in device tree.
+ * Returns 1 if rcc is available from secure world, 0 else.
+ ******************************************************************************/
+bool fdt_get_rcc_secure_status(void)
+{
+	int node;
+	void *fdt;
+
+	if (fdt_get_address(&fdt) == 0) {
+		return false;
+	}
+
+	node = fdt_node_offset_by_compatible(fdt, -1, DT_RCC_COMPAT);
+	if (node < 0) {
+		return false;
+	}
+
+	return fdt_check_secure_status(node);
+}
+
+/*******************************************************************************
+ * This function reads the stgen base address.
+ * It reads the value indicated inside the device tree.
+ * Returns address if success, and NULL value else.
+ ******************************************************************************/
+uintptr_t fdt_get_stgen_base(void)
+{
+	int node;
+	const fdt32_t *cuint;
+	void *fdt;
+
+	if (fdt_get_address(&fdt) == 0) {
+		return 0;
+	}
+
+	node = fdt_node_offset_by_compatible(fdt, -1, DT_STGEN_COMPAT);
+	if (node < 0) {
+		return 0;
+	}
+
+	cuint = fdt_getprop(fdt, node, "reg", NULL);
+	if (cuint == NULL) {
+		return 0;
+	}
+
+	return fdt32_to_cpu(*cuint);
+}
+
+/*******************************************************************************
+ * This function gets the clock ID of the given node.
+ * It reads the value indicated inside the device tree.
+ * Returns ID if success, and a negative value else.
+ ******************************************************************************/
+int fdt_get_clock_id(int node)
+{
+	const fdt32_t *cuint;
+	void *fdt;
+
+	if (fdt_get_address(&fdt) == 0) {
+		return -ENOENT;
+	}
+
+	cuint = fdt_getprop(fdt, node, "clocks", NULL);
+	if (cuint == NULL) {
+		return -FDT_ERR_NOTFOUND;
+	}
+
+	cuint++;
+	return (int)fdt32_to_cpu(*cuint);
+}