Diff: targets/TARGET_STM/TARGET_STM32F2/serial_api.c

Revision:

149:156823d33999

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_STM/TARGET_STM32F2/serial_api.c	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,1029 @@
+/* mbed Microcontroller Library
+ *******************************************************************************
+ * Copyright (c) 2016, STMicroelectronics
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of STMicroelectronics nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *******************************************************************************
+ */
+#include "mbed_assert.h"
+#include "serial_api.h"
+
+#if DEVICE_SERIAL
+
+#include "cmsis.h"
+#include "pinmap.h"
+#include <string.h>
+#include "PeripheralPins.h"
+#include "mbed_error.h"
+
+#define UART_NUM (8)
+
+static uint32_t serial_irq_ids[UART_NUM] = {0};
+static UART_HandleTypeDef uart_handlers[UART_NUM];
+
+static uart_irq_handler irq_handler;
+
+int stdio_uart_inited = 0;
+serial_t stdio_uart;
+
+#if DEVICE_SERIAL_ASYNCH
+    #define SERIAL_S(obj) (&((obj)->serial))
+#else
+    #define SERIAL_S(obj) (obj)
+#endif
+
+static void init_uart(serial_t *obj)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+    huart->Instance = (USART_TypeDef *)(obj_s->uart);
+
+    huart->Init.BaudRate     = obj_s->baudrate;
+    huart->Init.WordLength   = obj_s->databits;
+    huart->Init.StopBits     = obj_s->stopbits;
+    huart->Init.Parity       = obj_s->parity;
+#if DEVICE_SERIAL_FC
+    huart->Init.HwFlowCtl    = obj_s->hw_flow_ctl;
+#else
+    huart->Init.HwFlowCtl    = UART_HWCONTROL_NONE;
+#endif
+    huart->TxXferCount       = 0;
+    huart->TxXferSize        = 0;
+    huart->RxXferCount       = 0;
+    huart->RxXferSize        = 0;
+
+    if (obj_s->pin_rx == NC) {
+        huart->Init.Mode = UART_MODE_TX;
+    } else if (obj_s->pin_tx == NC) {
+        huart->Init.Mode = UART_MODE_RX;
+    } else {
+        huart->Init.Mode = UART_MODE_TX_RX;
+    }
+
+    if (HAL_UART_Init(huart) != HAL_OK) {
+        error("Cannot initialize UART\n");
+    }
+}
+
+void serial_init(serial_t *obj, PinName tx, PinName rx)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    
+    // Determine the UART to use (UART_1, UART_2, ...)
+    UARTName uart_tx = (UARTName)pinmap_peripheral(tx, PinMap_UART_TX);
+    UARTName uart_rx = (UARTName)pinmap_peripheral(rx, PinMap_UART_RX);
+
+    // Get the peripheral name (UART_1, UART_2, ...) from the pin and assign it to the object
+    obj_s->uart = (UARTName)pinmap_merge(uart_tx, uart_rx);
+    MBED_ASSERT(obj_s->uart != (UARTName)NC);
+
+    // Enable USART clock
+    switch (obj_s->uart) {
+        case UART_1:
+            __HAL_RCC_USART1_FORCE_RESET();
+            __HAL_RCC_USART1_RELEASE_RESET();
+            __HAL_RCC_USART1_CLK_ENABLE();
+            obj_s->index = 0;
+            break;
+
+        case UART_2:
+            __HAL_RCC_USART2_FORCE_RESET();
+            __HAL_RCC_USART2_RELEASE_RESET();
+            __HAL_RCC_USART2_CLK_ENABLE();
+            obj_s->index = 1;
+            break;
+
+#if defined(USART3_BASE)
+        case UART_3:
+            __HAL_RCC_USART3_FORCE_RESET();
+            __HAL_RCC_USART3_RELEASE_RESET();
+            __HAL_RCC_USART3_CLK_ENABLE();
+            obj_s->index = 2;
+            break;
+#endif
+#if defined(UART4_BASE)
+        case UART_4:
+            __HAL_RCC_UART4_FORCE_RESET();
+            __HAL_RCC_UART4_RELEASE_RESET();
+            __HAL_RCC_UART4_CLK_ENABLE();
+            obj_s->index = 3;
+            break;
+#endif
+#if defined(UART5_BASE)
+        case UART_5:
+            __HAL_RCC_UART5_FORCE_RESET();
+            __HAL_RCC_UART5_RELEASE_RESET();
+            __HAL_RCC_UART5_CLK_ENABLE();
+            obj_s->index = 4;
+            break;
+#endif
+#if defined(USART6_BASE)
+        case UART_6:
+            __HAL_RCC_USART6_FORCE_RESET();
+            __HAL_RCC_USART6_RELEASE_RESET();
+            __HAL_RCC_USART6_CLK_ENABLE();
+            obj_s->index = 5;
+            break;
+#endif
+#if defined(UART7_BASE)
+        case UART_7:
+            __HAL_RCC_UART7_FORCE_RESET();
+            __HAL_RCC_UART7_RELEASE_RESET();
+            __HAL_RCC_UART7_CLK_ENABLE();
+            obj_s->index = 6;
+            break;
+#endif
+#if defined(UART8_BASE)
+        case UART_8:
+            __HAL_RCC_UART8_FORCE_RESET();
+            __HAL_RCC_UART8_RELEASE_RESET();
+            __HAL_RCC_UART8_CLK_ENABLE();
+            obj_s->index = 7;
+            break;
+#endif
+    }
+
+    // Configure the UART pins
+    pinmap_pinout(tx, PinMap_UART_TX);
+    pinmap_pinout(rx, PinMap_UART_RX);
+
+    if (tx != NC) {
+        pin_mode(tx, PullUp);
+    }
+    if (rx != NC) {
+        pin_mode(rx, PullUp);
+    }
+
+    // Configure UART
+    obj_s->baudrate = 9600;
+    obj_s->databits = UART_WORDLENGTH_8B;
+    obj_s->stopbits = UART_STOPBITS_1;
+    obj_s->parity   = UART_PARITY_NONE;
+    
+#if DEVICE_SERIAL_FC
+    obj_s->hw_flow_ctl = UART_HWCONTROL_NONE;
+#endif
+
+    obj_s->pin_tx = tx;
+    obj_s->pin_rx = rx;
+
+    init_uart(obj);
+
+    // For stdio management
+    if (obj_s->uart == STDIO_UART) {
+        stdio_uart_inited = 1;
+        memcpy(&stdio_uart, obj, sizeof(serial_t));
+    }
+}
+
+void serial_free(serial_t *obj)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+      
+    // Reset UART and disable clock
+    switch (obj_s->index) {
+        case 0:
+            __USART1_FORCE_RESET();
+            __USART1_RELEASE_RESET();
+            __USART1_CLK_DISABLE();
+            break;
+
+        case 1:
+            __USART2_FORCE_RESET();
+            __USART2_RELEASE_RESET();
+            __USART2_CLK_DISABLE();
+            break;
+
+#if defined(USART3_BASE)
+        case 2:
+            __USART3_FORCE_RESET();
+            __USART3_RELEASE_RESET();
+            __USART3_CLK_DISABLE();
+            break;
+#endif
+#if defined(UART4_BASE)
+        case 3:
+            __UART4_FORCE_RESET();
+            __UART4_RELEASE_RESET();
+            __UART4_CLK_DISABLE();
+            break;
+#endif
+#if defined(UART5_BASE)
+        case 4:
+            __UART5_FORCE_RESET();
+            __UART5_RELEASE_RESET();
+            __UART5_CLK_DISABLE();
+            break;
+#endif
+#if defined(USART6_BASE)
+        case 5:
+            __USART6_FORCE_RESET();
+            __USART6_RELEASE_RESET();
+            __USART6_CLK_DISABLE();
+            break;
+#endif
+#if defined(UART7_BASE)
+        case 6:
+            __UART7_FORCE_RESET();
+            __UART7_RELEASE_RESET();
+            __UART7_CLK_DISABLE();
+            break;
+#endif
+#if defined(UART8_BASE)
+        case 7:
+            __UART8_FORCE_RESET();
+            __UART8_RELEASE_RESET();
+            __UART8_CLK_DISABLE();
+            break;
+#endif
+    }
+
+    // Configure GPIOs
+    pin_function(obj_s->pin_tx, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
+    pin_function(obj_s->pin_rx, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
+
+    serial_irq_ids[obj_s->index] = 0;
+}
+
+void serial_baud(serial_t *obj, int baudrate)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+
+    obj_s->baudrate = baudrate;
+    init_uart(obj);
+}
+
+void serial_format(serial_t *obj, int data_bits, SerialParity parity, int stop_bits)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+
+    if (data_bits == 9) {
+        obj_s->databits = UART_WORDLENGTH_9B;
+    } else {
+        obj_s->databits = UART_WORDLENGTH_8B;
+    }
+
+    switch (parity) {
+        case ParityOdd:
+            obj_s->parity = UART_PARITY_ODD;
+            break;
+        case ParityEven:
+            obj_s->parity = UART_PARITY_EVEN;
+            break;
+        default: // ParityNone
+        case ParityForced0: // unsupported!
+        case ParityForced1: // unsupported!
+            obj_s->parity = UART_PARITY_NONE;
+            break;
+    }
+
+    if (stop_bits == 2) {
+        obj_s->stopbits = UART_STOPBITS_2;
+    } else {
+        obj_s->stopbits = UART_STOPBITS_1;
+    }
+
+    init_uart(obj);
+}
+
+/******************************************************************************
+ * INTERRUPTS HANDLING
+ ******************************************************************************/
+
+static void uart_irq(int id)
+{
+    UART_HandleTypeDef * huart = &uart_handlers[id];
+    
+    if (serial_irq_ids[id] != 0) {
+        if (__HAL_UART_GET_FLAG(huart, UART_FLAG_TC) != RESET) {
+            if (__HAL_UART_GET_IT_SOURCE(huart, UART_IT_TC) != RESET) {
+                irq_handler(serial_irq_ids[id], TxIrq);
+                __HAL_UART_CLEAR_FLAG(huart, UART_FLAG_TC);
+            }
+        }
+        if (__HAL_UART_GET_FLAG(huart, UART_FLAG_RXNE) != RESET) {
+            if (__HAL_UART_GET_IT_SOURCE(huart, UART_IT_RXNE) != RESET) {
+                irq_handler(serial_irq_ids[id], RxIrq);
+                __HAL_UART_CLEAR_FLAG(huart, UART_FLAG_RXNE);
+            }
+        }
+        if (__HAL_UART_GET_FLAG(huart, UART_FLAG_ORE) != RESET) {
+            if (__HAL_UART_GET_IT_SOURCE(huart, USART_IT_ERR) != RESET) {
+                volatile uint32_t tmpval = huart->Instance->DR; // Clear ORE flag
+            }
+        }
+    }
+}
+
+static void uart1_irq(void)
+{
+    uart_irq(0);
+}
+
+static void uart2_irq(void)
+{
+    uart_irq(1);
+}
+
+#if defined(USART3_BASE)
+static void uart3_irq(void)
+{
+    uart_irq(2);
+}
+#endif
+
+#if defined(UART4_BASE)
+static void uart4_irq(void)
+{
+    uart_irq(3);
+}
+#endif
+
+#if defined(UART5_BASE)
+static void uart5_irq(void)
+{
+    uart_irq(4);
+}
+#endif
+
+#if defined(USART6_BASE)
+static void uart6_irq(void)
+{
+    uart_irq(5);
+}
+#endif
+
+#if defined(UART7_BASE)
+static void uart7_irq(void)
+{
+    uart_irq(6);
+}
+#endif
+
+#if defined(UART8_BASE)
+static void uart8_irq(void)
+{
+    uart_irq(7);
+}
+#endif
+
+void serial_irq_handler(serial_t *obj, uart_irq_handler handler, uint32_t id)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+  
+    irq_handler = handler;
+    serial_irq_ids[obj_s->index] = id;
+}
+
+void serial_irq_set(serial_t *obj, SerialIrq irq, uint32_t enable)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+    IRQn_Type irq_n = (IRQn_Type)0;
+    uint32_t vector = 0;
+
+    switch (obj_s->index) {
+        case 0:
+            irq_n = USART1_IRQn;
+            vector = (uint32_t)&uart1_irq;
+            break;
+
+        case 1:
+            irq_n = USART2_IRQn;
+            vector = (uint32_t)&uart2_irq;
+            break;
+#if defined(USART3_BASE)
+        case 2:
+            irq_n = USART3_IRQn;
+            vector = (uint32_t)&uart3_irq;
+            break;
+#endif
+#if defined(UART4_BASE)
+        case 3:
+            irq_n = UART4_IRQn;
+            vector = (uint32_t)&uart4_irq;
+            break;
+#endif
+#if defined(UART5_BASE)
+        case 4:
+            irq_n = UART5_IRQn;
+            vector = (uint32_t)&uart5_irq;
+            break;
+#endif
+#if defined(USART6_BASE)
+        case 5:
+            irq_n = USART6_IRQn;
+            vector = (uint32_t)&uart6_irq;
+            break;
+#endif
+#if defined(UART7_BASE)
+        case 6:
+            irq_n = UART7_IRQn;
+            vector = (uint32_t)&uart7_irq;
+            break;
+#endif
+#if defined(UART8_BASE)
+        case 7:
+            irq_n = UART8_IRQn;
+            vector = (uint32_t)&uart8_irq;
+            break;
+#endif
+    }
+
+    if (enable) {
+        if (irq == RxIrq) {
+            __HAL_UART_ENABLE_IT(huart, UART_IT_RXNE);
+        } else { // TxIrq
+            __HAL_UART_ENABLE_IT(huart, UART_IT_TC);
+        }
+            NVIC_SetVector(irq_n, vector);
+            NVIC_EnableIRQ(irq_n);
+
+    } else { // disable
+        int all_disabled = 0;
+        if (irq == RxIrq) {
+            __HAL_UART_DISABLE_IT(huart, UART_IT_RXNE);
+            // Check if TxIrq is disabled too
+            if ((huart->Instance->CR1 & USART_CR1_TXEIE) == 0) {
+                all_disabled = 1;
+            }
+        } else { // TxIrq
+            __HAL_UART_DISABLE_IT(huart, UART_IT_TC);
+            // Check if RxIrq is disabled too
+            if ((huart->Instance->CR1 & USART_CR1_RXNEIE) == 0) {
+                all_disabled = 1;
+            }
+        }
+
+        if (all_disabled) {
+            NVIC_DisableIRQ(irq_n);
+        }
+    }
+}
+
+/******************************************************************************
+ * READ/WRITE
+ ******************************************************************************/
+
+int serial_getc(serial_t *obj)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+
+    while (!serial_readable(obj));
+    return (int)(huart->Instance->DR & (uint16_t)0x1FF);
+}
+
+void serial_putc(serial_t *obj, int c)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+
+    while (!serial_writable(obj));
+    huart->Instance->DR = (uint32_t)(c & (uint16_t)0x1FF);
+}
+
+int serial_readable(serial_t *obj)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+    
+    // Check if data is received
+    return (__HAL_UART_GET_FLAG(huart, UART_FLAG_RXNE) != RESET) ? 1 : 0;
+}
+
+int serial_writable(serial_t *obj)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+    
+    // Check if data is transmitted
+    return (__HAL_UART_GET_FLAG(huart, UART_FLAG_TXE) != RESET) ? 1 : 0;
+}
+
+void serial_clear(serial_t *obj)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+    
+    huart->TxXferCount = 0;
+    huart->RxXferCount = 0;
+}
+
+void serial_pinout_tx(PinName tx)
+{
+    pinmap_pinout(tx, PinMap_UART_TX);
+}
+
+void serial_break_set(serial_t *obj)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+    
+    HAL_LIN_SendBreak(huart);
+}
+
+void serial_break_clear(serial_t *obj)
+{
+    (void)obj;
+}
+
+#if DEVICE_SERIAL_ASYNCH
+
+/******************************************************************************
+ * LOCAL HELPER FUNCTIONS
+ ******************************************************************************/
+
+/** 
+ * Configure the TX buffer for an asynchronous write serial transaction
+ *
+ * @param obj       The serial object.
+ * @param tx        The buffer for sending.
+ * @param tx_length The number of words to transmit.
+ */
+static void serial_tx_buffer_set(serial_t *obj, void *tx, int tx_length, uint8_t width)
+{
+    (void)width;
+
+    // Exit if a transmit is already on-going
+    if (serial_tx_active(obj)) {
+        return;
+    }
+
+    obj->tx_buff.buffer = tx;
+    obj->tx_buff.length = tx_length;
+    obj->tx_buff.pos = 0;
+}
+  
+/**
+ * Configure the RX buffer for an asynchronous write serial transaction
+ *
+ * @param obj       The serial object.
+ * @param tx        The buffer for sending.
+ * @param tx_length The number of words to transmit.
+ */
+static void serial_rx_buffer_set(serial_t *obj, void *rx, int rx_length, uint8_t width)
+{
+    (void)width;
+
+    // Exit if a reception is already on-going
+    if (serial_rx_active(obj)) {
+        return;
+    }
+
+    obj->rx_buff.buffer = rx;
+    obj->rx_buff.length = rx_length;
+    obj->rx_buff.pos = 0;
+}
+
+/** 
+ * Configure events
+ *
+ * @param obj    The serial object
+ * @param event  The logical OR of the events to configure
+ * @param enable Set to non-zero to enable events, or zero to disable them
+ */
+static void serial_enable_event(serial_t *obj, int event, uint8_t enable)
+{  
+    struct serial_s *obj_s = SERIAL_S(obj);
+    
+    // Shouldn't have to enable interrupt here, just need to keep track of the requested events.
+    if (enable) {
+        obj_s->events |= event;
+    } else {
+        obj_s->events &= ~event;
+    }
+}
+
+
+/**
+* Get index of serial object TX IRQ, relating it to the physical peripheral.
+*
+* @param obj pointer to serial object
+* @return internal NVIC TX IRQ index of U(S)ART peripheral
+*/
+static IRQn_Type serial_get_irq_n(serial_t *obj)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    IRQn_Type irq_n;
+
+    switch (obj_s->index) {
+#if defined(USART1_BASE)
+        case 0:
+            irq_n = USART1_IRQn;
+            break;
+#endif
+#if defined(USART2_BASE)
+        case 1:
+            irq_n = USART2_IRQn;
+            break;
+#endif
+#if defined(USART3_BASE)
+        case 2:
+            irq_n = USART3_IRQn;
+            break;
+#endif
+#if defined(UART4_BASE)
+        case 3:
+            irq_n = UART4_IRQn;
+            break;
+#endif
+#if defined(UART5_BASE)
+        case 4:
+            irq_n = UART5_IRQn;
+            break;
+#endif
+#if defined(USART6_BASE)
+        case 5:
+            irq_n = USART6_IRQn;
+            break;
+#endif
+#if defined(UART7_BASE)
+        case 6:
+            irq_n = UART7_IRQn;
+            break;
+#endif
+#if defined(UART8_BASE)
+        case 7:
+            irq_n = UART8_IRQn;
+            break;
+#endif      
+        default:
+            irq_n = (IRQn_Type)0;
+    }
+
+    return irq_n;
+}
+
+
+/******************************************************************************
+ * MBED API FUNCTIONS
+ ******************************************************************************/
+
+/** 
+ * Begin asynchronous TX transfer. The used buffer is specified in the serial
+ * object, tx_buff
+ *
+ * @param obj       The serial object
+ * @param tx        The buffer for sending
+ * @param tx_length The number of words to transmit
+ * @param tx_width  The bit width of buffer word
+ * @param handler   The serial handler
+ * @param event     The logical OR of events to be registered
+ * @param hint      A suggestion for how to use DMA with this transfer
+ * @return Returns number of data transfered, or 0 otherwise
+ */
+int serial_tx_asynch(serial_t *obj, const void *tx, size_t tx_length, uint8_t tx_width, uint32_t handler, uint32_t event, DMAUsage hint)
+{    
+    // TODO: DMA usage is currently ignored
+    (void) hint;
+    
+    // Check buffer is ok
+    MBED_ASSERT(tx != (void*)0);
+    MBED_ASSERT(tx_width == 8); // support only 8b width
+    
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef * huart = &uart_handlers[obj_s->index];
+
+    if (tx_length == 0) {
+        return 0;
+    }
+  
+    // Set up buffer
+    serial_tx_buffer_set(obj, (void *)tx, tx_length, tx_width);
+  
+    // Set up events
+    serial_enable_event(obj, SERIAL_EVENT_TX_ALL, 0); // Clear all events
+    serial_enable_event(obj, event, 1); // Set only the wanted events
+    
+    // Enable interrupt
+    IRQn_Type irq_n = serial_get_irq_n(obj);
+    NVIC_ClearPendingIRQ(irq_n);
+    NVIC_DisableIRQ(irq_n);
+    NVIC_SetPriority(irq_n, 1);
+    NVIC_SetVector(irq_n, (uint32_t)handler);
+    NVIC_EnableIRQ(irq_n);
+
+    // the following function will enable UART_IT_TXE and error interrupts
+    if (HAL_UART_Transmit_IT(huart, (uint8_t*)tx, tx_length) != HAL_OK) {
+        return 0;
+    }
+    
+    return tx_length;
+}
+
+/** 
+ * Begin asynchronous RX transfer (enable interrupt for data collecting)
+ * The used buffer is specified in the serial object, rx_buff
+ *
+ * @param obj        The serial object
+ * @param rx         The buffer for sending
+ * @param rx_length  The number of words to transmit
+ * @param rx_width   The bit width of buffer word
+ * @param handler    The serial handler
+ * @param event      The logical OR of events to be registered
+ * @param handler    The serial handler
+ * @param char_match A character in range 0-254 to be matched
+ * @param hint       A suggestion for how to use DMA with this transfer
+ */
+void serial_rx_asynch(serial_t *obj, void *rx, size_t rx_length, uint8_t rx_width, uint32_t handler, uint32_t event, uint8_t char_match, DMAUsage hint)
+{
+    // TODO: DMA usage is currently ignored
+    (void) hint;
+
+    /* Sanity check arguments */
+    MBED_ASSERT(obj);
+    MBED_ASSERT(rx != (void*)0);
+    MBED_ASSERT(rx_width == 8); // support only 8b width
+    
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+
+    serial_enable_event(obj, SERIAL_EVENT_RX_ALL, 0);
+    serial_enable_event(obj, event, 1);
+    
+    // set CharMatch
+    obj->char_match = char_match;
+    
+    serial_rx_buffer_set(obj, rx, rx_length, rx_width);
+
+    IRQn_Type irq_n = serial_get_irq_n(obj);
+    NVIC_ClearPendingIRQ(irq_n);
+    NVIC_DisableIRQ(irq_n);
+    NVIC_SetPriority(irq_n, 0);
+    NVIC_SetVector(irq_n, (uint32_t)handler);
+    NVIC_EnableIRQ(irq_n);
+
+    // following HAL function will enable the RXNE interrupt + error interrupts    
+    HAL_UART_Receive_IT(huart, (uint8_t*)rx, rx_length);
+}
+
+/**
+ * Attempts to determine if the serial peripheral is already in use for TX
+ *
+ * @param obj The serial object
+ * @return Non-zero if the TX transaction is ongoing, 0 otherwise
+ */
+uint8_t serial_tx_active(serial_t *obj)
+{
+    MBED_ASSERT(obj);
+    
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+    
+    return ((HAL_UART_GetState(huart) == HAL_UART_STATE_BUSY_TX) ? 1 : 0);
+}
+
+/**
+ * Attempts to determine if the serial peripheral is already in use for RX
+ *
+ * @param obj The serial object
+ * @return Non-zero if the RX transaction is ongoing, 0 otherwise
+ */
+uint8_t serial_rx_active(serial_t *obj)
+{
+    MBED_ASSERT(obj);
+    
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+    
+    return ((HAL_UART_GetState(huart) == HAL_UART_STATE_BUSY_RX) ? 1 : 0);
+}
+
+void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart) {
+    if (__HAL_UART_GET_FLAG(huart, UART_FLAG_TC) != RESET) {
+        __HAL_UART_CLEAR_FLAG(huart, UART_FLAG_TC);
+    }
+}
+
+void HAL_UART_ErrorCallback(UART_HandleTypeDef *huart) {
+    if (__HAL_UART_GET_FLAG(huart, UART_FLAG_PE) != RESET) {
+        volatile uint32_t tmpval = huart->Instance->DR; // Clear PE flag
+    } else if (__HAL_UART_GET_FLAG(huart, UART_FLAG_FE) != RESET) {
+        volatile uint32_t tmpval = huart->Instance->DR; // Clear FE flag
+    } else if (__HAL_UART_GET_FLAG(huart, UART_FLAG_NE) != RESET) {
+        volatile uint32_t tmpval = huart->Instance->DR; // Clear NE flag
+    } else if (__HAL_UART_GET_FLAG(huart, UART_FLAG_ORE) != RESET) {
+        volatile uint32_t tmpval = huart->Instance->DR; // Clear ORE flag
+    }
+}
+
+/**
+ * The asynchronous TX and RX handler.
+ *
+ * @param obj The serial object
+ * @return Returns event flags if a TX/RX transfer termination condition was met or 0 otherwise
+ */
+int serial_irq_handler_asynch(serial_t *obj)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+    
+    volatile int return_event = 0;
+    uint8_t *buf = (uint8_t*)(obj->rx_buff.buffer);
+    uint8_t i = 0;
+    
+    // TX PART:
+    if (__HAL_UART_GET_FLAG(huart, UART_FLAG_TC) != RESET) {
+        if (__HAL_UART_GET_IT_SOURCE(huart, UART_IT_TC) != RESET) {
+            // Return event SERIAL_EVENT_TX_COMPLETE if requested
+            if ((obj_s->events & SERIAL_EVENT_TX_COMPLETE ) != 0) {
+                return_event |= (SERIAL_EVENT_TX_COMPLETE & obj_s->events);
+            }
+        }
+    }
+    
+    // Handle error events
+    if (__HAL_UART_GET_FLAG(huart, UART_FLAG_PE) != RESET) {
+        if (__HAL_UART_GET_IT_SOURCE(huart, USART_IT_ERR) != RESET) {
+            return_event |= (SERIAL_EVENT_RX_PARITY_ERROR & obj_s->events);
+        }
+    }
+    
+    if (__HAL_UART_GET_FLAG(huart, UART_FLAG_FE) != RESET) {
+        if (__HAL_UART_GET_IT_SOURCE(huart, USART_IT_ERR) != RESET) {
+            return_event |= (SERIAL_EVENT_RX_FRAMING_ERROR & obj_s->events);
+        }
+    }
+    
+    if (__HAL_UART_GET_FLAG(huart, UART_FLAG_ORE) != RESET) {
+        if (__HAL_UART_GET_IT_SOURCE(huart, USART_IT_ERR) != RESET) {
+            return_event |= (SERIAL_EVENT_RX_OVERRUN_ERROR & obj_s->events);
+        }
+    }
+    
+    HAL_UART_IRQHandler(huart);
+    
+    // Abort if an error occurs
+    if (return_event & SERIAL_EVENT_RX_PARITY_ERROR ||
+            return_event & SERIAL_EVENT_RX_FRAMING_ERROR ||
+            return_event & SERIAL_EVENT_RX_OVERRUN_ERROR) {
+        return return_event;
+    }
+    
+    //RX PART
+    if (huart->RxXferSize != 0) {
+        obj->rx_buff.pos = huart->RxXferSize - huart->RxXferCount;
+    }
+    if ((huart->RxXferCount == 0) && (obj->rx_buff.pos >= (obj->rx_buff.length - 1))) {
+        return_event |= (SERIAL_EVENT_RX_COMPLETE & obj_s->events);
+    }
+    
+    // Check if char_match is present
+    if (obj_s->events & SERIAL_EVENT_RX_CHARACTER_MATCH) {
+        if (buf != NULL) {
+            for (i = 0; i < obj->rx_buff.pos; i++) {
+                if (buf[i] == obj->char_match) {
+                    obj->rx_buff.pos = i;
+                    return_event |= (SERIAL_EVENT_RX_CHARACTER_MATCH & obj_s->events);
+                    serial_rx_abort_asynch(obj);
+                    break;
+                }
+            }
+        }
+    }
+    
+    return return_event;  
+}
+
+/** 
+ * Abort the ongoing TX transaction. It disables the enabled interupt for TX and
+ * flush TX hardware buffer if TX FIFO is used
+ *
+ * @param obj The serial object
+ */
+void serial_tx_abort_asynch(serial_t *obj)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+    
+    __HAL_UART_DISABLE_IT(huart, UART_IT_TC);
+    __HAL_UART_DISABLE_IT(huart, UART_IT_TXE);
+    
+    // clear flags
+    __HAL_UART_CLEAR_FLAG(huart, UART_FLAG_TC);
+    
+    // reset states
+    huart->TxXferCount = 0;
+    // update handle state
+    if(huart->gState == HAL_UART_STATE_BUSY_TX_RX) {
+        huart->gState = HAL_UART_STATE_BUSY_RX;
+    } else {
+        huart->gState = HAL_UART_STATE_READY;
+    }
+}
+
+/**
+ * Abort the ongoing RX transaction It disables the enabled interrupt for RX and
+ * flush RX hardware buffer if RX FIFO is used
+ *
+ * @param obj The serial object
+ */
+void serial_rx_abort_asynch(serial_t *obj)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+    UART_HandleTypeDef *huart = &uart_handlers[obj_s->index];
+    
+    // disable interrupts
+    __HAL_UART_DISABLE_IT(huart, UART_IT_RXNE);
+    __HAL_UART_DISABLE_IT(huart, UART_IT_PE);
+    __HAL_UART_DISABLE_IT(huart, UART_IT_ERR);
+    
+    // clear flags
+    __HAL_UART_CLEAR_FLAG(huart, UART_FLAG_RXNE);
+    volatile uint32_t tmpval = huart->Instance->DR; // Clear error flags
+    
+    // reset states
+    huart->RxXferCount = 0;
+    // update handle state
+    if(huart->RxState == HAL_UART_STATE_BUSY_TX_RX) {
+        huart->RxState = HAL_UART_STATE_BUSY_TX;
+    } else {
+        huart->RxState = HAL_UART_STATE_READY;
+    }
+}
+
+#endif
+
+#if DEVICE_SERIAL_FC
+
+/**
+ * Set HW Control Flow
+ * @param obj    The serial object
+ * @param type   The Control Flow type (FlowControlNone, FlowControlRTS, FlowControlCTS, FlowControlRTSCTS)
+ * @param rxflow Pin for the rxflow
+ * @param txflow Pin for the txflow
+ */
+void serial_set_flow_control(serial_t *obj, FlowControl type, PinName rxflow, PinName txflow)
+{
+    struct serial_s *obj_s = SERIAL_S(obj);
+
+    // Determine the UART to use (UART_1, UART_2, ...)
+    UARTName uart_rts = (UARTName)pinmap_peripheral(rxflow, PinMap_UART_RTS);
+    UARTName uart_cts = (UARTName)pinmap_peripheral(txflow, PinMap_UART_CTS);
+
+    // Get the peripheral name (UART_1, UART_2, ...) from the pin and assign it to the object
+    obj_s->uart = (UARTName)pinmap_merge(uart_cts, uart_rts);
+    MBED_ASSERT(obj_s->uart != (UARTName)NC);
+
+    if(type == FlowControlNone) {
+        // Disable hardware flow control
+      obj_s->hw_flow_ctl = UART_HWCONTROL_NONE;
+    }
+    if (type == FlowControlRTS) {
+        // Enable RTS
+        MBED_ASSERT(uart_rts != (UARTName)NC);
+        obj_s->hw_flow_ctl = UART_HWCONTROL_RTS;
+        obj_s->pin_rts = rxflow;
+        // Enable the pin for RTS function
+        pinmap_pinout(rxflow, PinMap_UART_RTS);
+    }
+    if (type == FlowControlCTS) {
+        // Enable CTS
+        MBED_ASSERT(uart_cts != (UARTName)NC);
+        obj_s->hw_flow_ctl = UART_HWCONTROL_CTS;
+        obj_s->pin_cts = txflow;
+        // Enable the pin for CTS function
+        pinmap_pinout(txflow, PinMap_UART_CTS);
+    }
+    if (type == FlowControlRTSCTS) {
+        // Enable CTS & RTS
+        MBED_ASSERT(uart_rts != (UARTName)NC);
+        MBED_ASSERT(uart_cts != (UARTName)NC);
+        obj_s->hw_flow_ctl = UART_HWCONTROL_RTS_CTS;
+        obj_s->pin_rts = rxflow;
+        obj_s->pin_cts = txflow;
+        // Enable the pin for CTS function
+        pinmap_pinout(txflow, PinMap_UART_CTS);
+        // Enable the pin for RTS function
+        pinmap_pinout(rxflow, PinMap_UART_RTS);
+    }
+    
+    init_uart(obj);
+}
+
+#endif
+
+#endif