feat(drivers/st/uart): add uart driver for STM32MP1

Add a UART/USART driver for STM32 with complete a hardware support;
it used for STM32CubeProgrammer support with even parity.

This driver is not used for console, which is already handle
by a simple driver (drivers/st/uart/aarch32/stm32_console.S).

Change-Id: Ia9266e5d177fe7fd09c8a15b81da1a05b1bc8b2d
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>
diff --git a/drivers/st/clk/stm32mp_clkfunc.c b/drivers/st/clk/stm32mp_clkfunc.c
index d57f120..0db0dee 100644
--- a/drivers/st/clk/stm32mp_clkfunc.c
+++ b/drivers/st/clk/stm32mp_clkfunc.c
@@ -14,6 +14,7 @@
 #include <drivers/st/stm32_gpio.h>
 #include <drivers/st/stm32mp_clkfunc.h>
 
+#define DT_UART_COMPAT		"st,stm32h7-uart"
 /*
  * Get the frequency of an oscillator from its name in device tree.
  * @param name: oscillator name
@@ -297,3 +298,32 @@
 	cuint++;
 	return (int)fdt32_to_cpu(*cuint);
 }
+
+/*
+ * Get the frequency of the specified UART instance.
+ * @param instance: UART interface registers base address.
+ * @return: clock frequency on success, 0 value on failure.
+ */
+unsigned long fdt_get_uart_clock_freq(uintptr_t instance)
+{
+	void *fdt;
+	int node;
+	int clk_id;
+
+	if (fdt_get_address(&fdt) == 0) {
+		return 0UL;
+	}
+
+	/* Check for UART nodes */
+	node = dt_match_instance_by_compatible(DT_UART_COMPAT, instance);
+	if (node < 0) {
+		return 0UL;
+	}
+
+	clk_id = fdt_get_clock_id(node);
+	if (clk_id < 0) {
+		return 0UL;
+	}
+
+	return stm32mp_clk_get_rate((unsigned long)clk_id);
+}
diff --git a/drivers/st/uart/stm32_uart.c b/drivers/st/uart/stm32_uart.c
new file mode 100644
index 0000000..e2e5405
--- /dev/null
+++ b/drivers/st/uart/stm32_uart.c
@@ -0,0 +1,404 @@
+/*
+ * Copyright (c) 2021, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+
+#include <common/bl_common.h>
+#include <drivers/delay_timer.h>
+#include <drivers/st/stm32_uart.h>
+#include <drivers/st/stm32_uart_regs.h>
+#include <drivers/st/stm32mp_clkfunc.h>
+#include <lib/mmio.h>
+
+#include <platform_def.h>
+
+/* UART time-out value */
+#define STM32_UART_TIMEOUT_US	20000U
+
+/* Mask to clear ALL the configuration registers */
+
+#define STM32_UART_CR1_FIELDS \
+		(USART_CR1_M | USART_CR1_PCE | USART_CR1_PS | USART_CR1_TE | \
+		 USART_CR1_RE | USART_CR1_OVER8 | USART_CR1_FIFOEN)
+
+#define STM32_UART_CR2_FIELDS \
+		(USART_CR2_SLVEN | USART_CR2_DIS_NSS | USART_CR2_ADDM7 | \
+		 USART_CR2_LBDL | USART_CR2_LBDIE | USART_CR2_LBCL | \
+		 USART_CR2_CPHA | USART_CR2_CPOL | USART_CR2_CLKEN | \
+		 USART_CR2_STOP | USART_CR2_LINEN | USART_CR2_SWAP | \
+		 USART_CR2_RXINV | USART_CR2_TXINV | USART_CR2_DATAINV | \
+		 USART_CR2_MSBFIRST | USART_CR2_ABREN | USART_CR2_ABRMODE | \
+		 USART_CR2_RTOEN | USART_CR2_ADD)
+
+#define STM32_UART_CR3_FIELDS \
+		(USART_CR3_EIE | USART_CR3_IREN | USART_CR3_IRLP | \
+		 USART_CR3_HDSEL | USART_CR3_NACK | USART_CR3_SCEN | \
+		 USART_CR3_DMAR | USART_CR3_DMAT | USART_CR3_RTSE | \
+		 USART_CR3_CTSE | USART_CR3_CTSIE | USART_CR3_ONEBIT | \
+		 USART_CR3_OVRDIS | USART_CR3_DDRE | USART_CR3_DEM | \
+		 USART_CR3_DEP | USART_CR3_SCARCNT | USART_CR3_WUS | \
+		 USART_CR3_WUFIE | USART_CR3_TXFTIE | USART_CR3_TCBGTIE | \
+		 USART_CR3_RXFTCFG | USART_CR3_RXFTIE | USART_CR3_TXFTCFG)
+
+#define STM32_UART_ISR_ERRORS	 \
+		(USART_ISR_ORE | USART_ISR_NE |  USART_ISR_FE | USART_ISR_PE)
+
+static const uint16_t presc_table[STM32_UART_PRESCALER_NB] = {
+	1U, 2U, 4U, 6U, 8U, 10U, 12U, 16U, 32U, 64U, 128U, 256U
+};
+
+/* @brief  BRR division operation to set BRR register in 8-bit oversampling
+ * mode.
+ * @param  clockfreq: UART clock.
+ * @param  baud_rate: Baud rate set by the user.
+ * @param  prescaler: UART prescaler value.
+ * @retval Division result.
+ */
+static uint32_t uart_div_sampling8(unsigned long clockfreq,
+				   uint32_t baud_rate,
+				   uint32_t prescaler)
+{
+	uint32_t scaled_freq = clockfreq / presc_table[prescaler];
+
+	return ((scaled_freq * 2) + (baud_rate / 2)) / baud_rate;
+
+}
+
+/* @brief  BRR division operation to set BRR register in 16-bit oversampling
+ * mode.
+ * @param  clockfreq: UART clock.
+ * @param  baud_rate: Baud rate set by the user.
+ * @param  prescaler: UART prescaler value.
+ * @retval Division result.
+ */
+static uint32_t uart_div_sampling16(unsigned long clockfreq,
+				    uint32_t baud_rate,
+				    uint32_t prescaler)
+{
+	uint32_t scaled_freq = clockfreq / presc_table[prescaler];
+
+	return (scaled_freq + (baud_rate / 2)) / baud_rate;
+
+}
+
+/*
+ * @brief  Return the UART clock frequency.
+ * @param  huart: UART handle.
+ * @retval Frequency value in Hz.
+ */
+static unsigned long uart_get_clock_freq(struct stm32_uart_handle_s *huart)
+{
+	return fdt_get_uart_clock_freq((uintptr_t)huart->base);
+}
+
+/*
+ * @brief  Configure the UART peripheral.
+ * @param  huart: UART handle.
+ * @retval UART status.
+ */
+static int uart_set_config(struct stm32_uart_handle_s *huart,
+			   const struct stm32_uart_init_s *init)
+{
+	uint32_t tmpreg;
+	unsigned long clockfreq;
+	uint32_t brrtemp;
+
+	/*
+	 * ---------------------- USART CR1 Configuration --------------------
+	 * Clear M, PCE, PS, TE, RE and OVER8 bits and configure
+	 * the UART word length, parity, mode and oversampling:
+	 * - set the M bits according to init->word_length value,
+	 * - set PCE and PS bits according to init->parity value,
+	 * - set TE and RE bits according to init->mode value,
+	 * - set OVER8 bit according to init->over_sampling value.
+	 */
+	tmpreg = init->word_length |
+		 init->parity |
+		 init->mode |
+		 init->over_sampling |
+		 init->fifo_mode;
+	mmio_clrsetbits_32(huart->base + USART_CR1, STM32_UART_CR1_FIELDS, tmpreg);
+
+	/*
+	 * --------------------- USART CR2 Configuration ---------------------
+	 * Configure the UART Stop Bits: Set STOP[13:12] bits according
+	 * to init->stop_bits value.
+	 */
+	mmio_clrsetbits_32(huart->base + USART_CR2, STM32_UART_CR2_FIELDS,
+			   init->stop_bits);
+
+	/*
+	 * --------------------- USART CR3 Configuration ---------------------
+	 * Configure:
+	 * - UART HardWare Flow Control: set CTSE and RTSE bits according
+	 *   to init->hw_flow_control value,
+	 * - one-bit sampling method versus three samples' majority rule
+	 *   according to init->one_bit_sampling (not applicable to
+	 *   LPUART),
+	 * - set TXFTCFG bit according to init->tx_fifo_threshold value,
+	 * - set RXFTCFG bit according to init->rx_fifo_threshold value.
+	 */
+	tmpreg = init->hw_flow_control | init->one_bit_sampling;
+
+	if (init->fifo_mode == USART_CR1_FIFOEN) {
+		tmpreg |= init->tx_fifo_threshold |
+			  init->rx_fifo_threshold;
+	}
+
+	mmio_clrsetbits_32(huart->base + USART_CR3, STM32_UART_CR3_FIELDS, tmpreg);
+
+	/*
+	 * --------------------- USART PRESC Configuration -------------------
+	 * Configure UART Clock Prescaler : set PRESCALER according to
+	 * init->prescaler value.
+	 */
+	assert(init->prescaler < STM32_UART_PRESCALER_NB);
+	mmio_clrsetbits_32(huart->base + USART_PRESC, USART_PRESC_PRESCALER,
+			   init->prescaler);
+
+	/*---------------------- USART BRR configuration --------------------*/
+	clockfreq = uart_get_clock_freq(huart);
+	if (clockfreq == 0UL) {
+		return -ENODEV;
+	}
+
+	if (init->over_sampling == STM32_UART_OVERSAMPLING_8) {
+		uint32_t usartdiv = uart_div_sampling8(clockfreq,
+						       init->baud_rate,
+						       init->prescaler);
+
+		brrtemp = (usartdiv & USART_BRR_DIV_MANTISSA) |
+			  ((usartdiv & USART_BRR_DIV_FRACTION) >> 1);
+	} else {
+		brrtemp = uart_div_sampling16(clockfreq,
+					      init->baud_rate,
+					      init->prescaler) &
+			  (USART_BRR_DIV_FRACTION | USART_BRR_DIV_MANTISSA);
+	}
+	mmio_write_32(huart->base + USART_BRR, brrtemp);
+
+	return 0;
+}
+
+/*
+ * @brief  Handle UART communication timeout.
+ * @param  huart: UART handle.
+ * @param  flag: Specifies the UART flag to check.
+ * @retval UART status.
+ */
+static int stm32_uart_wait_flag(struct stm32_uart_handle_s *huart, uint32_t flag)
+{
+	uint64_t timeout_ref = timeout_init_us(STM32_UART_TIMEOUT_US);
+
+	while ((mmio_read_32(huart->base + USART_ISR) & flag) == 0U) {
+		if (timeout_elapsed(timeout_ref)) {
+			return -ETIMEDOUT;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * @brief  Check the UART idle State.
+ * @param  huart: UART handle.
+ * @retval UART status.
+ */
+static int stm32_uart_check_idle(struct stm32_uart_handle_s *huart)
+{
+	int ret;
+
+	/* Check if the transmitter is enabled */
+	if ((mmio_read_32(huart->base + USART_CR1) & USART_CR1_TE) == USART_CR1_TE) {
+		ret = stm32_uart_wait_flag(huart, USART_ISR_TEACK);
+		if (ret != 0) {
+			return ret;
+		}
+	}
+
+	/* Check if the receiver is enabled */
+	if ((mmio_read_32(huart->base + USART_CR1) & USART_CR1_RE) == USART_CR1_RE) {
+		ret = stm32_uart_wait_flag(huart, USART_ISR_REACK);
+		if (ret != 0) {
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * @brief  Compute RDR register mask depending on word length.
+ * @param  huart: UART handle.
+ * @retval Mask value.
+ */
+static unsigned int stm32_uart_rdr_mask(const struct stm32_uart_init_s *init)
+{
+	unsigned int mask = 0U;
+
+	switch (init->word_length) {
+	case STM32_UART_WORDLENGTH_9B:
+		mask = GENMASK(8, 0);
+		break;
+	case STM32_UART_WORDLENGTH_8B:
+		mask = GENMASK(7, 0);
+		break;
+	case STM32_UART_WORDLENGTH_7B:
+		mask = GENMASK(6, 0);
+		break;
+	default:
+		break; /* not reached */
+	}
+
+	if (init->parity != STM32_UART_PARITY_NONE) {
+		mask >>= 1;
+	}
+
+	return mask;
+}
+
+/*
+ * @brief  Check interrupt and status errors.
+ * @retval True if error detected, false otherwise.
+ */
+static bool stm32_uart_error_detected(struct stm32_uart_handle_s *huart)
+{
+	return (mmio_read_32(huart->base + USART_ISR) & STM32_UART_ISR_ERRORS) != 0U;
+}
+
+/*
+ * @brief  Clear status errors.
+ */
+static void stm32_uart_error_clear(struct stm32_uart_handle_s *huart)
+{
+	mmio_write_32(huart->base + USART_ICR, STM32_UART_ISR_ERRORS);
+}
+
+/*
+ * @brief  Stop the UART.
+ * @param  base: UART base address.
+ */
+void stm32_uart_stop(uintptr_t base)
+{
+	mmio_clrbits_32(base + USART_CR1, USART_CR1_UE);
+}
+
+/*
+ * @brief  Initialize UART.
+ * @param  huart: UART handle.
+ * @param  base_addr: base address of UART.
+ * @param  init: UART initialization parameter.
+ * @retval UART status.
+ */
+
+int stm32_uart_init(struct stm32_uart_handle_s *huart,
+		    uintptr_t base_addr,
+		    const struct stm32_uart_init_s *init)
+{
+	int ret;
+
+	if (huart == NULL || init == NULL || base_addr == 0U) {
+		return -EINVAL;
+	}
+
+	huart->base = base_addr;
+
+	/* Disable the peripheral */
+	stm32_uart_stop(huart->base);
+
+	/* Computation of UART mask to apply to RDR register */
+	huart->rdr_mask = stm32_uart_rdr_mask(init);
+
+	/* Init the peripheral */
+	ret = uart_set_config(huart, init);
+	if (ret != 0) {
+		return ret;
+	}
+
+	/* Enable the peripheral */
+	mmio_setbits_32(huart->base + USART_CR1, USART_CR1_UE);
+
+	/* TEACK and/or REACK to check */
+	return stm32_uart_check_idle(huart);
+}
+
+/*
+ * @brief  Transmit one data in no blocking mode.
+ * @param  huart: UART handle.
+ * @param  c: data to sent.
+ * @retval UART status.
+ */
+int stm32_uart_putc(struct stm32_uart_handle_s *huart, int c)
+{
+	int ret;
+
+	if (huart == NULL) {
+		return -EINVAL;
+	}
+
+	ret = stm32_uart_wait_flag(huart, USART_ISR_TXE);
+	if (ret != 0) {
+		return ret;
+	}
+
+	mmio_write_32(huart->base + USART_TDR, c);
+	if (stm32_uart_error_detected(huart)) {
+		stm32_uart_error_clear(huart);
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+/*
+ * @brief  Flush TX Transmit fifo
+ * @param  huart: UART handle.
+ * @retval UART status.
+ */
+int stm32_uart_flush(struct stm32_uart_handle_s *huart)
+{
+	int ret;
+
+	if (huart == NULL) {
+		return -EINVAL;
+	}
+
+	ret = stm32_uart_wait_flag(huart, USART_ISR_TXE);
+	if (ret != 0) {
+		return ret;
+	}
+
+	return stm32_uart_wait_flag(huart, USART_ISR_TC);
+}
+
+/*
+ * @brief  Receive a data in no blocking mode.
+ * @retval value if >0 or UART status.
+ */
+int stm32_uart_getc(struct stm32_uart_handle_s *huart)
+{
+	uint32_t data;
+
+	if (huart == NULL) {
+		return -EINVAL;
+	}
+
+	/* Check if data is available */
+	if ((mmio_read_32(huart->base + USART_ISR) & USART_ISR_RXNE) == 0U) {
+		return -EAGAIN;
+	}
+
+	data = mmio_read_32(huart->base + USART_RDR) & huart->rdr_mask;
+
+	if (stm32_uart_error_detected(huart)) {
+		stm32_uart_error_clear(huart);
+		return -EFAULT;
+	}
+
+	return (int)data;
+}
diff --git a/include/drivers/st/stm32_uart.h b/include/drivers/st/stm32_uart.h
new file mode 100644
index 0000000..212968f
--- /dev/null
+++ b/include/drivers/st/stm32_uart.h
@@ -0,0 +1,170 @@
+/*
+ * Copyright (c) 2021, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef STM32_UART_H
+#define STM32_UART_H
+
+/* UART word length */
+#define STM32_UART_WORDLENGTH_7B		USART_CR1_M1
+#define STM32_UART_WORDLENGTH_8B		0x00000000U
+#define STM32_UART_WORDLENGTH_9B		USART_CR1_M0
+
+/* UART number of stop bits */
+#define STM32_UART_STOPBITS_0_5			USART_CR2_STOP_0
+#define STM32_UART_STOPBITS_1			0x00000000U
+#define STM32_UART_STOPBITS_1_5			(USART_CR2_STOP_0 | USART_CR2_STOP_1)
+#define STM32_UART_STOPBITS_2			USART_CR2_STOP_1
+
+/* UART parity */
+#define STM32_UART_PARITY_NONE			0x00000000U
+#define STM32_UART_PARITY_EVEN			USART_CR1_PCE
+#define STM32_UART_PARITY_ODD			(USART_CR1_PCE | USART_CR1_PS)
+
+/* UART transfer mode */
+#define STM32_UART_MODE_RX			USART_CR1_RE
+#define STM32_UART_MODE_TX			USART_CR1_TE
+#define STM32_UART_MODE_TX_RX			(USART_CR1_TE | USART_CR1_RE)
+
+/* UART hardware flow control */
+#define STM32_UART_HWCONTROL_NONE		0x00000000U
+#define STM32_UART_HWCONTROL_RTS		USART_CR3_RTSE
+#define STM32_UART_HWCONTROL_CTS		USART_CR3_CTSE
+#define STM32_UART_HWCONTROL_RTS_CTS		(USART_CR3_RTSE | USART_CR3_CTSE)
+
+/* UART over sampling */
+#define STM32_UART_OVERSAMPLING_16		0x00000000U
+#define STM32_UART_OVERSAMPLING_8		USART_CR1_OVER8
+
+/* UART prescaler */
+#define STM32_UART_PRESCALER_DIV1		0x00000000U
+#define STM32_UART_PRESCALER_DIV2		0x00000001U
+#define STM32_UART_PRESCALER_DIV4		0x00000002U
+#define STM32_UART_PRESCALER_DIV6		0x00000003U
+#define STM32_UART_PRESCALER_DIV8		0x00000004U
+#define STM32_UART_PRESCALER_DIV10		0x00000005U
+#define STM32_UART_PRESCALER_DIV12		0x00000006U
+#define STM32_UART_PRESCALER_DIV16		0x00000007U
+#define STM32_UART_PRESCALER_DIV32		0x00000008U
+#define STM32_UART_PRESCALER_DIV64		0x00000009U
+#define STM32_UART_PRESCALER_DIV128		0x0000000AU
+#define STM32_UART_PRESCALER_DIV256		0x0000000BU
+#define STM32_UART_PRESCALER_NB			0x0000000CU
+
+/* UART fifo mode */
+#define STM32_UART_FIFOMODE_EN			USART_CR1_FIFOEN
+#define STM32_UART_FIFOMODE_DIS			0x00000000U
+
+/* UART TXFIFO threshold level */
+#define STM32_UART_TXFIFO_THRESHOLD_1EIGHTHFULL		0x00000000U
+#define STM32_UART_TXFIFO_THRESHOLD_1QUARTERFUL		USART_CR3_TXFTCFG_0
+#define STM32_UART_TXFIFO_THRESHOLD_HALFFULL		USART_CR3_TXFTCFG_1
+#define STM32_UART_TXFIFO_THRESHOLD_3QUARTERSFULL	(USART_CR3_TXFTCFG_0 | USART_CR3_TXFTCFG_1)
+#define STM32_UART_TXFIFO_THRESHOLD_7EIGHTHFULL		USART_CR3_TXFTCFG_2
+#define STM32_UART_TXFIFO_THRESHOLD_EMPTY		(USART_CR3_TXFTCFG_2 | USART_CR3_TXFTCFG_0)
+
+/* UART RXFIFO threshold level */
+#define STM32_UART_RXFIFO_THRESHOLD_1EIGHTHFULL		0x00000000U
+#define STM32_UART_RXFIFO_THRESHOLD_1QUARTERFULL	USART_CR3_RXFTCFG_0
+#define STM32_UART_RXFIFO_THRESHOLD_HALFFULL		USART_CR3_RXFTCFG_1
+#define STM32_UART_RXFIFO_THRESHOLD_3QUARTERSFULL	(USART_CR3_RXFTCFG_0 | USART_CR3_RXFTCFG_1)
+#define STM32_UART_RXFIFO_THRESHOLD_7EIGHTHFULL		USART_CR3_RXFTCFG_2
+#define STM32_UART_RXFIFO_THRESHOLD_FULL		(USART_CR3_RXFTCFG_2 | USART_CR3_RXFTCFG_0)
+
+struct stm32_uart_init_s {
+	uint32_t baud_rate;		/*
+					 * Configures the UART communication
+					 * baud rate.
+					 */
+
+	uint32_t word_length;		/*
+					 * Specifies the number of data bits
+					 * transmitted or received in a frame.
+					 * This parameter can be a value of
+					 * @ref STM32_UART_WORDLENGTH_*.
+					 */
+
+	uint32_t stop_bits;		/*
+					 * Specifies the number of stop bits
+					 * transmitted. This parameter can be
+					 * a value of @ref STM32_UART_STOPBITS_*.
+					 */
+
+	uint32_t parity;		/*
+					 * Specifies the parity mode.
+					 * This parameter can be a value of
+					 * @ref STM32_UART_PARITY_*.
+					 */
+
+	uint32_t mode;			/*
+					 * Specifies whether the receive or
+					 * transmit mode is enabled or
+					 * disabled. This parameter can be a
+					 * value of @ref @ref STM32_UART_MODE_*.
+					 */
+
+	uint32_t hw_flow_control;	/*
+					 * Specifies whether the hardware flow
+					 * control mode is enabled or
+					 * disabled. This parameter can be a
+					 * value of @ref STM32_UARTHWCONTROL_*.
+					 */
+
+	uint32_t over_sampling;		/*
+					 * Specifies whether the over sampling
+					 * 8 is enabled or disabled.
+					 * This parameter can be a value of
+					 * @ref STM32_UART_OVERSAMPLING_*.
+					 */
+
+	uint32_t one_bit_sampling;	/*
+					 * Specifies whether a single sample
+					 * or three samples' majority vote is
+					 * selected. This parameter can be 0
+					 * or USART_CR3_ONEBIT.
+					 */
+
+	uint32_t prescaler;		/*
+					 * Specifies the prescaler value used
+					 * to divide the UART clock source.
+					 * This parameter can be a value of
+					 * @ref STM32_UART_PRESCALER_*.
+					 */
+
+	uint32_t fifo_mode;		/*
+					 * Specifies if the FIFO mode will be
+					 * used. This parameter can be a value
+					 * of @ref STM32_UART_FIFOMODE_*.
+					 */
+
+	uint32_t tx_fifo_threshold;	/*
+					 * Specifies the TXFIFO threshold
+					 * level. This parameter can be a
+					 * value of @ref
+					 * STM32_UART_TXFIFO_THRESHOLD_*.
+					 */
+
+	uint32_t rx_fifo_threshold;	/*
+					 * Specifies the RXFIFO threshold
+					 * level. This parameter can be a
+					 * value of @ref
+					 * STM32_UART_RXFIFO_THRESHOLD_*.
+					 */
+};
+
+struct stm32_uart_handle_s {
+	uint32_t base;
+	uint32_t rdr_mask;
+};
+
+int stm32_uart_init(struct stm32_uart_handle_s *huart,
+		    uintptr_t base_addr,
+		    const struct stm32_uart_init_s *init);
+void stm32_uart_stop(uintptr_t base_addr);
+int stm32_uart_putc(struct stm32_uart_handle_s *huart, int c);
+int stm32_uart_flush(struct stm32_uart_handle_s *huart);
+int stm32_uart_getc(struct stm32_uart_handle_s *huart);
+
+#endif /* STM32_UART_H */
diff --git a/include/drivers/st/stm32mp_clkfunc.h b/include/drivers/st/stm32mp_clkfunc.h
index c3329cc..a282035 100644
--- a/include/drivers/st/stm32mp_clkfunc.h
+++ b/include/drivers/st/stm32mp_clkfunc.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2020, STMicroelectronics - All Rights Reserved
+ * Copyright (c) 2017-2021, STMicroelectronics - All Rights Reserved
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -26,5 +26,6 @@
 bool fdt_get_rcc_secure_status(void);
 
 int fdt_get_clock_id(int node);
+unsigned long fdt_get_uart_clock_freq(uintptr_t instance);
 
 #endif /* STM32MP_CLKFUNC_H */