diff --git a/drivers/st/pmic/stm32_i2c.c b/drivers/st/pmic/stm32_i2c.c
new file mode 100644
index 0000000..0980139
--- /dev/null
+++ b/drivers/st/pmic/stm32_i2c.c
@@ -0,0 +1,851 @@
+/*
+ * Copyright (c) 2016-2018, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch_helpers.h>
+#include <delay_timer.h>
+#include <errno.h>
+#include <mmio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stm32_i2c.h>
+
+/* STM32 I2C registers offsets */
+#define I2C_CR1			0x00U
+#define I2C_CR2			0x04U
+#define I2C_OAR1		0x08U
+#define I2C_OAR2		0x0CU
+#define I2C_TIMINGR		0x10U
+#define I2C_TIMEOUTR		0x14U
+#define I2C_ISR			0x18U
+#define I2C_ICR			0x1CU
+#define I2C_PECR		0x20U
+#define I2C_RXDR		0x24U
+#define I2C_TXDR		0x28U
+
+#define MAX_DELAY		0xFFFFFFFFU
+
+/* I2C TIMING clear register Mask */
+#define TIMING_CLEAR_MASK	0xF0FFFFFFU
+/* Timeout 25 ms */
+#define I2C_TIMEOUT_BUSY	25U
+
+#define MAX_NBYTE_SIZE		255U
+
+static int i2c_request_memory_write(struct i2c_handle_s *hi2c,
+				    uint16_t dev_addr, uint16_t mem_addr,
+				    uint16_t mem_add_size, uint32_t timeout,
+				    uint32_t tick_start);
+static int i2c_request_memory_read(struct i2c_handle_s *hi2c, uint16_t dev_addr,
+				   uint16_t mem_addr, uint16_t mem_add_size,
+				   uint32_t timeout, uint32_t tick_start);
+
+/* Private functions to handle flags during polling transfer */
+static int i2c_wait_flag(struct i2c_handle_s *hi2c, uint32_t flag,
+			 uint8_t awaited_value, uint32_t timeout,
+			 uint32_t tick_start);
+static int i2c_wait_txis(struct i2c_handle_s *hi2c, uint32_t timeout,
+			 uint32_t tick_start);
+static int i2c_wait_stop(struct i2c_handle_s *hi2c, uint32_t timeout,
+			 uint32_t tick_start);
+static int i2c_ack_failed(struct i2c_handle_s *hi2c, uint32_t timeout,
+			  uint32_t tick_start);
+
+/* Private function to flush TXDR register */
+static void i2c_flush_txdr(struct i2c_handle_s *hi2c);
+
+/* Private function to start, restart or stop a transfer */
+static void i2c_transfer_config(struct i2c_handle_s *hi2c, uint16_t dev_addr,
+				uint16_t size, uint32_t i2c_mode,
+				uint32_t request);
+
+/*
+ * @brief  Initialize the I2C device.
+ * @param  hi2c: Pointer to a struct i2c_handle_s structure that contains
+ *               the configuration information for the specified I2C.
+ * @retval 0 if OK, negative value else
+ */
+int stm32_i2c_init(struct i2c_handle_s *hi2c)
+{
+	if (hi2c == NULL) {
+		return -ENOENT;
+	}
+
+	if (hi2c->i2c_state == I2C_STATE_RESET) {
+		hi2c->lock = 0;
+	}
+
+	hi2c->i2c_state = I2C_STATE_BUSY;
+
+	/* Disable the selected I2C peripheral */
+	mmio_clrbits_32(hi2c->i2c_base_addr + I2C_CR1, I2C_CR1_PE);
+
+	/* Configure I2Cx: Frequency range */
+	mmio_write_32(hi2c->i2c_base_addr + I2C_TIMINGR,
+		      hi2c->i2c_init.timing & TIMING_CLEAR_MASK);
+
+	/* Disable Own Address1 before set the Own Address1 configuration */
+	mmio_clrbits_32(hi2c->i2c_base_addr + I2C_OAR1, I2C_OAR1_OA1EN);
+
+	/* Configure I2Cx: Own Address1 and ack own address1 mode */
+	if (hi2c->i2c_init.addressing_mode == I2C_ADDRESSINGMODE_7BIT) {
+		mmio_write_32(hi2c->i2c_base_addr + I2C_OAR1,
+			      I2C_OAR1_OA1EN | hi2c->i2c_init.own_address1);
+	} else { /* I2C_ADDRESSINGMODE_10BIT */
+		mmio_write_32(hi2c->i2c_base_addr + I2C_OAR1,
+			      I2C_OAR1_OA1EN | I2C_OAR1_OA1MODE |
+			      hi2c->i2c_init.own_address1);
+	}
+
+	/* Configure I2Cx: Addressing Master mode */
+	if (hi2c->i2c_init.addressing_mode == I2C_ADDRESSINGMODE_10BIT) {
+		mmio_write_32(hi2c->i2c_base_addr + I2C_CR2, I2C_CR2_ADD10);
+	}
+
+	/*
+	 * Enable the AUTOEND by default, and enable NACK
+	 * (should be disable only during Slave process)
+	 */
+	mmio_setbits_32(hi2c->i2c_base_addr + I2C_CR2,
+			I2C_CR2_AUTOEND | I2C_CR2_NACK);
+
+	/* Disable Own Address2 before set the Own Address2 configuration */
+	mmio_clrbits_32(hi2c->i2c_base_addr + I2C_OAR2, I2C_DUALADDRESS_ENABLE);
+
+	/* Configure I2Cx: Dual mode and Own Address2 */
+	mmio_write_32(hi2c->i2c_base_addr + I2C_OAR2,
+		      hi2c->i2c_init.dual_address_mode |
+		      hi2c->i2c_init.own_address2 |
+		      (hi2c->i2c_init.own_address2_masks << 8));
+
+	/* Configure I2Cx: Generalcall and NoStretch mode */
+	mmio_write_32(hi2c->i2c_base_addr + I2C_CR1,
+		      hi2c->i2c_init.general_call_mode |
+		      hi2c->i2c_init.no_stretch_mode);
+
+	/* Enable the selected I2C peripheral */
+	mmio_setbits_32(hi2c->i2c_base_addr + I2C_CR1, I2C_CR1_PE);
+
+	hi2c->i2c_err = I2C_ERROR_NONE;
+	hi2c->i2c_state = I2C_STATE_READY;
+	hi2c->i2c_mode = I2C_MODE_NONE;
+
+	return 0;
+}
+
+/*
+ * @brief  Write an amount of data in blocking mode to a specific memory address
+ * @param  hi2c: Pointer to a struct i2c_handle_s structure that contains
+ *               the configuration information for the specified I2C.
+ * @param  dev_addr: Target device address
+ * @param  mem_addr: Internal memory address
+ * @param  mem_add_size: size of internal memory address
+ * @param  p_data: Pointer to data buffer
+ * @param  size: Amount of data to be sent
+ * @param  timeout: timeout duration
+ * @retval 0 if OK, negative value else
+ */
+int stm32_i2c_mem_write(struct i2c_handle_s *hi2c, uint16_t dev_addr,
+			uint16_t mem_addr, uint16_t mem_add_size,
+			uint8_t *p_data, uint16_t size, uint32_t timeout)
+{
+	uint32_t tickstart;
+
+	if ((hi2c->i2c_state != I2C_STATE_READY) || (hi2c->lock != 0U)) {
+		return -EBUSY;
+	}
+
+	if ((p_data == NULL) || (size == 0U)) {
+		return -EINVAL;
+	}
+
+	hi2c->lock = 1;
+
+	tickstart = (uint32_t)read_cntpct_el0();
+
+	if (i2c_wait_flag(hi2c, I2C_FLAG_BUSY, 1, I2C_TIMEOUT_BUSY,
+			  tickstart) != 0) {
+		return -EIO;
+	}
+
+	hi2c->i2c_state     = I2C_STATE_BUSY_TX;
+	hi2c->i2c_mode      = I2C_MODE_MEM;
+	hi2c->i2c_err = I2C_ERROR_NONE;
+
+	hi2c->p_buff  = p_data;
+	hi2c->xfer_count = size;
+
+	/* Send Slave Address and Memory Address */
+	if (i2c_request_memory_write(hi2c, dev_addr, mem_addr, mem_add_size,
+				     timeout, tickstart) != 0) {
+		hi2c->lock = 0;
+		return -EIO;
+	}
+
+	/*
+	 * Set NBYTES to write and reload
+	 * if hi2c->xfer_count > MAX_NBYTE_SIZE
+	 */
+	if (hi2c->xfer_count > MAX_NBYTE_SIZE) {
+		hi2c->xfer_size = MAX_NBYTE_SIZE;
+		i2c_transfer_config(hi2c, dev_addr, hi2c->xfer_size,
+				    I2C_RELOAD_MODE, I2C_NO_STARTSTOP);
+	} else {
+		hi2c->xfer_size = hi2c->xfer_count;
+		i2c_transfer_config(hi2c, dev_addr, hi2c->xfer_size,
+				    I2C_AUTOEND_MODE, I2C_NO_STARTSTOP);
+	}
+
+	do {
+		if (i2c_wait_txis(hi2c, timeout, tickstart) != 0) {
+			return -EIO;
+		}
+
+		mmio_write_8(hi2c->i2c_base_addr + I2C_TXDR, *hi2c->p_buff);
+		hi2c->p_buff++;
+		hi2c->xfer_count--;
+		hi2c->xfer_size--;
+
+		if ((hi2c->xfer_count != 0U) && (hi2c->xfer_size == 0U)) {
+			/* Wait until TCR flag is set */
+			if (i2c_wait_flag(hi2c, I2C_FLAG_TCR, 0, timeout,
+					  tickstart) != 0) {
+				return -EIO;
+		}
+
+			if (hi2c->xfer_count > MAX_NBYTE_SIZE) {
+				hi2c->xfer_size = MAX_NBYTE_SIZE;
+				i2c_transfer_config(hi2c, dev_addr,
+						    hi2c->xfer_size,
+						    I2C_RELOAD_MODE,
+						    I2C_NO_STARTSTOP);
+			} else {
+				hi2c->xfer_size = hi2c->xfer_count;
+				i2c_transfer_config(hi2c, dev_addr,
+						    hi2c->xfer_size,
+						    I2C_AUTOEND_MODE,
+						    I2C_NO_STARTSTOP);
+			}
+		}
+
+	} while (hi2c->xfer_count > 0U);
+
+	/*
+	 * No need to Check TC flag, with AUTOEND mode the stop
+	 * is automatically generated.
+	 * Wait until STOPF flag is reset.
+	 */
+	if (i2c_wait_stop(hi2c, timeout, tickstart) != 0) {
+		return -EIO;
+	}
+
+	mmio_write_32(hi2c->i2c_base_addr + I2C_ICR, I2C_FLAG_STOPF);
+
+	mmio_clrbits_32(hi2c->i2c_base_addr + I2C_CR2, I2C_RESET_CR2);
+
+	hi2c->i2c_state = I2C_STATE_READY;
+	hi2c->i2c_mode  = I2C_MODE_NONE;
+
+	hi2c->lock = 0;
+
+	return 0;
+}
+
+/*
+ * @brief  Read an amount of data in blocking mode from a specific memory
+ *	   address
+ * @param  hi2c: Pointer to a struct i2c_handle_s structure that contains
+ *               the configuration information for the specified I2C.
+ * @param  dev_addr: Target device address
+ * @param  mem_addr: Internal memory address
+ * @param  mem_add_size: size of internal memory address
+ * @param  p_data: Pointer to data buffer
+ * @param  size: Amount of data to be sent
+ * @param  timeout: timeout duration
+ * @retval 0 if OK, negative value else
+ */
+int stm32_i2c_mem_read(struct i2c_handle_s *hi2c, uint16_t dev_addr,
+		       uint16_t mem_addr, uint16_t mem_add_size,
+		       uint8_t *p_data, uint16_t size, uint32_t timeout)
+{
+	uint32_t tickstart;
+
+	if ((hi2c->i2c_state != I2C_STATE_READY) || (hi2c->lock != 0U)) {
+		return -EBUSY;
+	}
+
+	if ((p_data == NULL) || (size == 0U)) {
+		return  -EINVAL;
+	}
+
+	hi2c->lock = 1;
+
+	tickstart = (uint32_t)read_cntpct_el0();
+
+	if (i2c_wait_flag(hi2c, I2C_FLAG_BUSY, 1, I2C_TIMEOUT_BUSY,
+			  tickstart) != 0) {
+		return -EIO;
+	}
+
+	hi2c->i2c_state     = I2C_STATE_BUSY_RX;
+	hi2c->i2c_mode      = I2C_MODE_MEM;
+	hi2c->i2c_err = I2C_ERROR_NONE;
+
+	hi2c->p_buff  = p_data;
+	hi2c->xfer_count = size;
+
+	/* Send Slave Address and Memory Address */
+	if (i2c_request_memory_read(hi2c, dev_addr, mem_addr, mem_add_size,
+				    timeout, tickstart) != 0) {
+		hi2c->lock = 0;
+		return -EIO;
+	}
+
+	/*
+	 * Send Slave Address.
+	 * Set NBYTES to write and reload if hi2c->xfer_count > MAX_NBYTE_SIZE
+	 * and generate RESTART.
+	 */
+	if (hi2c->xfer_count > MAX_NBYTE_SIZE) {
+		hi2c->xfer_size = MAX_NBYTE_SIZE;
+		i2c_transfer_config(hi2c, dev_addr, hi2c->xfer_size,
+				    I2C_RELOAD_MODE, I2C_GENERATE_START_READ);
+	} else {
+		hi2c->xfer_size = hi2c->xfer_count;
+		i2c_transfer_config(hi2c, dev_addr, hi2c->xfer_size,
+				    I2C_AUTOEND_MODE, I2C_GENERATE_START_READ);
+	}
+
+	do {
+		if (i2c_wait_flag(hi2c, I2C_FLAG_RXNE, 0, timeout,
+				  tickstart) != 0) {
+			return -EIO;
+		}
+
+		*hi2c->p_buff = mmio_read_8(hi2c->i2c_base_addr + I2C_RXDR);
+		hi2c->p_buff++;
+		hi2c->xfer_size--;
+		hi2c->xfer_count--;
+
+		if ((hi2c->xfer_count != 0U) && (hi2c->xfer_size == 0U)) {
+			if (i2c_wait_flag(hi2c, I2C_FLAG_TCR, 0, timeout,
+					  tickstart) != 0) {
+				return -EIO;
+			}
+
+			if (hi2c->xfer_count > MAX_NBYTE_SIZE) {
+				hi2c->xfer_size = MAX_NBYTE_SIZE;
+				i2c_transfer_config(hi2c, dev_addr,
+						    hi2c->xfer_size,
+						    I2C_RELOAD_MODE,
+						    I2C_NO_STARTSTOP);
+			} else {
+				hi2c->xfer_size = hi2c->xfer_count;
+				i2c_transfer_config(hi2c, dev_addr,
+						    hi2c->xfer_size,
+						    I2C_AUTOEND_MODE,
+						    I2C_NO_STARTSTOP);
+			}
+		}
+	} while (hi2c->xfer_count > 0U);
+
+	/*
+	 * No need to Check TC flag, with AUTOEND mode the stop
+	 * is automatically generated
+	 * Wait until STOPF flag is reset
+	 */
+	if (i2c_wait_stop(hi2c, timeout, tickstart) != 0) {
+		return -EIO;
+	}
+
+	mmio_write_32(hi2c->i2c_base_addr + I2C_ICR, I2C_FLAG_STOPF);
+
+	mmio_clrbits_32(hi2c->i2c_base_addr + I2C_CR2, I2C_RESET_CR2);
+
+	hi2c->i2c_state = I2C_STATE_READY;
+	hi2c->i2c_mode  = I2C_MODE_NONE;
+
+	hi2c->lock = 0;
+
+	return 0;
+}
+
+/*
+ * @brief  Checks if target device is ready for communication.
+ * @note   This function is used with Memory devices
+ * @param  hi2c: Pointer to a struct i2c_handle_s structure that contains
+ *               the configuration information for the specified I2C.
+ * @param  dev_addr: Target device address
+ * @param  trials: Number of trials
+ * @param  timeout: timeout duration
+ * @retval 0 if OK, negative value else
+ */
+int stm32_i2c_is_device_ready(struct i2c_handle_s *hi2c,
+			      uint16_t dev_addr, uint32_t trials,
+			      uint32_t timeout)
+{
+	uint32_t i2c_trials = 0U;
+
+	if ((hi2c->i2c_state != I2C_STATE_READY) || (hi2c->lock != 0U)) {
+		return -EBUSY;
+	}
+
+	if ((mmio_read_32(hi2c->i2c_base_addr + I2C_ISR) & I2C_FLAG_BUSY) !=
+	    0U) {
+		return -EBUSY;
+	}
+
+	hi2c->lock = 1;
+
+	hi2c->i2c_state = I2C_STATE_BUSY;
+	hi2c->i2c_err = I2C_ERROR_NONE;
+
+	do {
+		uint32_t tickstart;
+
+		/* Generate Start */
+		if (hi2c->i2c_init.addressing_mode == I2C_ADDRESSINGMODE_7BIT) {
+			mmio_write_32(hi2c->i2c_base_addr + I2C_CR2,
+				      (((uint32_t)dev_addr & I2C_CR2_SADD) |
+				       I2C_CR2_START | I2C_CR2_AUTOEND) &
+				       ~I2C_CR2_RD_WRN);
+		} else {
+			mmio_write_32(hi2c->i2c_base_addr + I2C_CR2,
+				      (((uint32_t)dev_addr & I2C_CR2_SADD) |
+				       I2C_CR2_START | I2C_CR2_ADD10) &
+				      ~I2C_CR2_RD_WRN);
+		}
+
+		/*
+		 * No need to Check TC flag, with AUTOEND mode the stop
+		 * is automatically generated
+		 * Wait until STOPF flag is set or a NACK flag is set
+		 */
+		tickstart = (uint32_t)read_cntpct_el0();
+		while (((mmio_read_32(hi2c->i2c_base_addr + I2C_ISR) &
+			 (I2C_FLAG_STOPF | I2C_FLAG_AF)) == 0U) &&
+		       (hi2c->i2c_state != I2C_STATE_TIMEOUT)) {
+			if (timeout != MAX_DELAY) {
+				if ((((uint32_t)read_cntpct_el0() - tickstart) >
+				     timeout) || (timeout == 0U)) {
+					hi2c->i2c_state = I2C_STATE_READY;
+
+					hi2c->i2c_err |=
+						I2C_ERROR_TIMEOUT;
+
+					hi2c->lock = 0;
+
+					return -EIO;
+				}
+			}
+		}
+
+		/* Check if the NACKF flag has not been set */
+		if ((mmio_read_32(hi2c->i2c_base_addr + I2C_ISR) &
+		     I2C_FLAG_AF) == 0U) {
+			if (i2c_wait_flag(hi2c, I2C_FLAG_STOPF, 0, timeout,
+					  tickstart) != 0) {
+				return -EIO;
+			}
+
+			mmio_write_32(hi2c->i2c_base_addr + I2C_ICR,
+				      I2C_FLAG_STOPF);
+
+			hi2c->i2c_state = I2C_STATE_READY;
+
+			hi2c->lock = 0;
+
+			return 0;
+		}
+
+		if (i2c_wait_flag(hi2c, I2C_FLAG_STOPF, 0, timeout,
+				  tickstart) != 0) {
+			return -EIO;
+		}
+
+		mmio_write_32(hi2c->i2c_base_addr + I2C_ICR, I2C_FLAG_AF);
+
+		mmio_write_32(hi2c->i2c_base_addr + I2C_ICR, I2C_FLAG_STOPF);
+
+		if (i2c_trials == trials) {
+			mmio_setbits_32(hi2c->i2c_base_addr + I2C_CR2,
+					I2C_CR2_STOP);
+
+			if (i2c_wait_flag(hi2c, I2C_FLAG_STOPF, 0, timeout,
+					  tickstart) != 0) {
+				return -EIO;
+			}
+
+			mmio_write_32(hi2c->i2c_base_addr + I2C_ICR,
+				      I2C_FLAG_STOPF);
+		}
+
+		i2c_trials++;
+	} while (i2c_trials < trials);
+
+	hi2c->i2c_state = I2C_STATE_READY;
+
+	hi2c->i2c_err |= I2C_ERROR_TIMEOUT;
+
+	hi2c->lock = 0;
+
+	return -EIO;
+}
+
+/*
+ * @brief  Master sends target device address followed by internal memory
+ *	   address for write request.
+ * @param  hi2c: Pointer to a struct i2c_handle_s structure that contains
+ *               the configuration information for the specified I2C.
+ * @param  dev_addr: Target device address
+ * @param  mem_addr: Internal memory address
+ * @param  mem_add_size: size of internal memory address
+ * @param  timeout: timeout duration
+ * @param  tick_start Tick start value
+ * @retval 0 if OK, negative value else
+ */
+static int i2c_request_memory_write(struct i2c_handle_s *hi2c,
+				    uint16_t dev_addr, uint16_t mem_addr,
+				    uint16_t mem_add_size, uint32_t timeout,
+				    uint32_t tick_start)
+{
+	i2c_transfer_config(hi2c, dev_addr, mem_add_size, I2C_RELOAD_MODE,
+			    I2C_GENERATE_START_WRITE);
+
+	if (i2c_wait_txis(hi2c, timeout, tick_start) != 0) {
+		return -EIO;
+	}
+
+	if (mem_add_size == I2C_MEMADD_SIZE_8BIT) {
+		/* Send Memory Address */
+		mmio_write_8(hi2c->i2c_base_addr + I2C_TXDR,
+			     (uint8_t)(mem_addr & 0x00FFU));
+	} else {
+		/* Send MSB of Memory Address */
+		mmio_write_8(hi2c->i2c_base_addr + I2C_TXDR,
+			     (uint8_t)((mem_addr & 0xFF00U) >> 8));
+
+		/* Wait until TXIS flag is set */
+		if (i2c_wait_txis(hi2c, timeout, tick_start) != 0) {
+			return -EIO;
+		}
+
+		/* Send LSB of Memory Address */
+		mmio_write_8(hi2c->i2c_base_addr + I2C_TXDR,
+			     (uint8_t)(mem_addr & 0x00FFU));
+	}
+
+	if (i2c_wait_flag(hi2c, I2C_FLAG_TCR, 0, timeout, tick_start) !=
+	    0) {
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/*
+ * @brief  Master sends target device address followed by internal memory
+ *	   address for read request.
+ * @param  hi2c: Pointer to a struct i2c_handle_s structure that contains
+ *               the configuration information for the specified I2C.
+ * @param  dev_addr: Target device address
+ * @param  mem_addr: Internal memory address
+ * @param  mem_add_size: size of internal memory address
+ * @param  timeout: timeout duration
+ * @param  tick_start Tick start value
+ * @retval 0 if OK, negative value else
+ */
+static int i2c_request_memory_read(struct i2c_handle_s *hi2c, uint16_t dev_addr,
+				   uint16_t mem_addr, uint16_t mem_add_size,
+				   uint32_t timeout, uint32_t tick_start)
+{
+	i2c_transfer_config(hi2c, dev_addr, mem_add_size, I2C_SOFTEND_MODE,
+			    I2C_GENERATE_START_WRITE);
+
+	if (i2c_wait_txis(hi2c, timeout, tick_start) != 0) {
+		return -EIO;
+	}
+
+	if (mem_add_size == I2C_MEMADD_SIZE_8BIT) {
+		/* Send Memory Address */
+		mmio_write_8(hi2c->i2c_base_addr + I2C_TXDR,
+			     (uint8_t)(mem_addr & 0x00FFU));
+	} else {
+		/* Send MSB of Memory Address */
+		mmio_write_8(hi2c->i2c_base_addr + I2C_TXDR,
+			     (uint8_t)((mem_addr & 0xFF00U) >> 8));
+
+		/* Wait until TXIS flag is set */
+		if (i2c_wait_txis(hi2c, timeout, tick_start) != 0) {
+			return -EIO;
+		}
+
+		/* Send LSB of Memory Address */
+		mmio_write_8(hi2c->i2c_base_addr + I2C_TXDR,
+			     (uint8_t)(mem_addr & 0x00FFU));
+	}
+
+	if (i2c_wait_flag(hi2c, I2C_FLAG_TC, 0, timeout, tick_start) != 0) {
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/*
+ * @brief  I2C Tx data register flush process.
+ * @param  hi2c: I2C handle.
+ * @retval None
+ */
+static void i2c_flush_txdr(struct i2c_handle_s *hi2c)
+{
+	/*
+	 * If a pending TXIS flag is set,
+	 * write a dummy data in TXDR to clear it.
+	 */
+	if ((mmio_read_32(hi2c->i2c_base_addr + I2C_ISR) & I2C_FLAG_TXIS) !=
+	    0U) {
+		mmio_write_32(hi2c->i2c_base_addr + I2C_TXDR, 0);
+	}
+
+	/* Flush TX register if not empty */
+	if ((mmio_read_32(hi2c->i2c_base_addr + I2C_ISR) & I2C_FLAG_TXE) ==
+	    0U) {
+		mmio_setbits_32(hi2c->i2c_base_addr + I2C_ISR,
+				I2C_FLAG_TXE);
+	}
+}
+
+/*
+ * @brief  This function handles I2C Communication timeout.
+ * @param  hi2c: Pointer to a struct i2c_handle_s structure that contains
+ *               the configuration information for the specified I2C.
+ * @param  flag: Specifies the I2C flag to check.
+ * @param  awaited_value: The awaited bit value for the flag (0 or 1).
+ * @param  timeout: timeout duration
+ * @param  tick_start: Tick start value
+ * @retval 0 if OK, negative value else
+ */
+static int i2c_wait_flag(struct i2c_handle_s *hi2c, uint32_t flag,
+			 uint8_t awaited_value, uint32_t timeout,
+			 uint32_t tick_start)
+{
+	uint8_t flag_check;
+
+	do {
+		flag_check = ((mmio_read_32(hi2c->i2c_base_addr + I2C_ISR) &
+			       flag) == flag) ? 1U : 0U;
+
+		if (timeout != MAX_DELAY) {
+			if ((((uint32_t)read_cntpct_el0() - tick_start) >
+			     timeout) || (timeout == 0U)) {
+				hi2c->i2c_err |= I2C_ERROR_TIMEOUT;
+				hi2c->i2c_state = I2C_STATE_READY;
+				hi2c->i2c_mode = I2C_MODE_NONE;
+
+				hi2c->lock = 0;
+				return -EIO;
+			}
+		}
+	} while (flag_check == awaited_value);
+
+	return 0;
+}
+
+/*
+ * @brief  This function handles I2C Communication timeout for specific usage
+ *	   of TXIS flag.
+ * @param  hi2c: Pointer to a struct i2c_handle_s structure that contains
+ *               the configuration information for the specified I2C.
+ * @param  timeout: timeout duration
+ * @param  tick_start: Tick start value
+ * @retval 0 if OK, negative value else
+ */
+static int i2c_wait_txis(struct i2c_handle_s *hi2c, uint32_t timeout,
+			 uint32_t tick_start)
+{
+	while ((mmio_read_32(hi2c->i2c_base_addr + I2C_ISR) &
+		I2C_FLAG_TXIS) == 0U) {
+		if (i2c_ack_failed(hi2c, timeout, tick_start) != 0) {
+			return -EIO;
+		}
+
+		if (timeout != MAX_DELAY) {
+			if ((((uint32_t)read_cntpct_el0() - tick_start) >
+			     timeout) || (timeout == 0U)) {
+				hi2c->i2c_err |= I2C_ERROR_TIMEOUT;
+				hi2c->i2c_state = I2C_STATE_READY;
+				hi2c->i2c_mode = I2C_MODE_NONE;
+
+				hi2c->lock = 0;
+
+				return -EIO;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * @brief  This function handles I2C Communication timeout for specific
+ *	   usage of STOP flag.
+ * @param  hi2c: Pointer to a struct i2c_handle_s structure that contains
+ *               the configuration information for the specified I2C.
+ * @param  timeout: timeout duration
+ * @param  tick_start: Tick start value
+ * @retval 0 if OK, negative value else
+ */
+static int i2c_wait_stop(struct i2c_handle_s *hi2c, uint32_t timeout,
+			 uint32_t tick_start)
+{
+	while ((mmio_read_32(hi2c->i2c_base_addr + I2C_ISR) &
+		 I2C_FLAG_STOPF) == 0U) {
+		if (i2c_ack_failed(hi2c, timeout, tick_start) != 0) {
+			return -EIO;
+		}
+
+		if ((((uint32_t)read_cntpct_el0() - tick_start) > timeout) ||
+		    (timeout == 0U)) {
+			hi2c->i2c_err |= I2C_ERROR_TIMEOUT;
+			hi2c->i2c_state = I2C_STATE_READY;
+			hi2c->i2c_mode = I2C_MODE_NONE;
+
+			hi2c->lock = 0;
+
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * @brief  This function handles Acknowledge failed detection during
+ *	   an I2C Communication.
+ * @param  hi2c: Pointer to a struct i2c_handle_s structure that contains
+ *               the configuration information for the specified I2C.
+ * @param  timeout: timeout duration
+ * @param  tick_start: Tick start value
+ * @retval 0 if OK, negative value else
+ */
+static int i2c_ack_failed(struct i2c_handle_s *hi2c, uint32_t timeout,
+			  uint32_t tick_start)
+{
+	if ((mmio_read_32(hi2c->i2c_base_addr + I2C_ISR) & I2C_FLAG_AF) == 0U) {
+		return 0;
+	}
+
+	/*
+	 * Wait until STOP Flag is reset.
+	 * AutoEnd should be initiate after AF.
+	 */
+	while ((mmio_read_32(hi2c->i2c_base_addr + I2C_ISR) &
+		I2C_FLAG_STOPF) == 0U) {
+		if (timeout != MAX_DELAY) {
+			if ((((uint32_t)read_cntpct_el0() - tick_start) >
+			     timeout) || (timeout == 0U)) {
+				hi2c->i2c_err |= I2C_ERROR_TIMEOUT;
+				hi2c->i2c_state = I2C_STATE_READY;
+				hi2c->i2c_mode = I2C_MODE_NONE;
+
+				hi2c->lock = 0;
+
+				return -EIO;
+			}
+		}
+	}
+
+	mmio_write_32(hi2c->i2c_base_addr + I2C_ICR, I2C_FLAG_AF);
+
+	mmio_write_32(hi2c->i2c_base_addr + I2C_ICR, I2C_FLAG_STOPF);
+
+	i2c_flush_txdr(hi2c);
+
+	mmio_clrbits_32(hi2c->i2c_base_addr + I2C_CR2, I2C_RESET_CR2);
+
+	hi2c->i2c_err |= I2C_ERROR_AF;
+	hi2c->i2c_state = I2C_STATE_READY;
+	hi2c->i2c_mode = I2C_MODE_NONE;
+
+	hi2c->lock = 0;
+
+	return -EIO;
+}
+
+/*
+ * @brief  Handles I2Cx communication when starting transfer or during transfer
+ *	   (TC or TCR flag are set).
+ * @param  hi2c: I2C handle.
+ * @param  dev_addr: Specifies the slave address to be programmed.
+ * @param  size: Specifies the number of bytes to be programmed.
+ *   This parameter must be a value between 0 and 255.
+ * @param  i2c_mode: New state of the I2C START condition generation.
+ *   This parameter can be one of the following values:
+ *     @arg @ref I2C_RELOAD_MODE: Enable Reload mode .
+ *     @arg @ref I2C_AUTOEND_MODE: Enable Automatic end mode.
+ *     @arg @ref I2C_SOFTEND_MODE: Enable Software end mode.
+ * @param  request: New state of the I2C START condition generation.
+ *   This parameter can be one of the following values:
+ *     @arg @ref I2C_NO_STARTSTOP: Don't Generate stop and start condition.
+ *     @arg @ref I2C_GENERATE_STOP: Generate stop condition
+ *                                  (size should be set to 0).
+ *     @arg @ref I2C_GENERATE_START_READ: Generate Restart for read request.
+ *     @arg @ref I2C_GENERATE_START_WRITE: Generate Restart for write request.
+ * @retval None
+ */
+static void i2c_transfer_config(struct i2c_handle_s *hi2c, uint16_t dev_addr,
+				uint16_t size, uint32_t i2c_mode,
+				uint32_t request)
+{
+	uint32_t clr_value, set_value;
+
+	clr_value = (I2C_CR2_SADD | I2C_CR2_NBYTES | I2C_CR2_RELOAD |
+		     I2C_CR2_AUTOEND | I2C_CR2_START | I2C_CR2_STOP) |
+		(I2C_CR2_RD_WRN & (request >> (31U - I2C_CR2_RD_WRN_OFFSET)));
+
+	set_value = ((uint32_t)dev_addr & I2C_CR2_SADD) |
+		(((uint32_t)size << I2C_CR2_NBYTES_OFFSET) & I2C_CR2_NBYTES) |
+		i2c_mode | request;
+
+	mmio_clrsetbits_32(hi2c->i2c_base_addr + I2C_CR2, clr_value, set_value);
+}
+
+/*
+ * @brief  Configure I2C Analog noise filter.
+ * @param  hi2c: Pointer to a struct i2c_handle_s structure that contains
+ *               the configuration information for the specified I2Cx peripheral
+ * @param  analog_filter: New state of the Analog filter.
+ * @retval 0 if OK, negative value else
+ */
+int stm32_i2c_config_analog_filter(struct i2c_handle_s *hi2c,
+				   uint32_t analog_filter)
+{
+	if ((hi2c->i2c_state != I2C_STATE_READY) || (hi2c->lock != 0U)) {
+		return -EBUSY;
+	}
+
+	hi2c->lock = 1;
+
+	hi2c->i2c_state = I2C_STATE_BUSY;
+
+	/* Disable the selected I2C peripheral */
+	mmio_clrbits_32(hi2c->i2c_base_addr + I2C_CR1, I2C_CR1_PE);
+
+	/* Reset I2Cx ANOFF bit */
+	mmio_clrbits_32(hi2c->i2c_base_addr + I2C_CR1, I2C_CR1_ANFOFF);
+
+	/* Set analog filter bit*/
+	mmio_setbits_32(hi2c->i2c_base_addr + I2C_CR1, analog_filter);
+
+	/* Enable the selected I2C peripheral */
+	mmio_setbits_32(hi2c->i2c_base_addr + I2C_CR1, I2C_CR1_PE);
+
+	hi2c->i2c_state = I2C_STATE_READY;
+
+	hi2c->lock = 0;
+
+	return 0;
+}