From ec36ce72c8a0a8bacfa5657ad2507be463e6ee41 Mon Sep 17 00:00:00 2001
From: bcostm <bco.stm@gmail.com>
Date: Fri, 10 Jun 2016 11:26:15 +0200
Subject: [PATCH] Add force/release reset during Serial init phase

---
 .../hal/TARGET_STM/TARGET_STM32F3/serial_api.c       | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/hal/targets/hal/TARGET_STM/TARGET_STM32F3/serial_api.c b/hal/targets/hal/TARGET_STM/TARGET_STM32F3/serial_api.c
index a035b33ad0..381aae3837 100644
--- a/hal/targets/hal/TARGET_STM/TARGET_STM32F3/serial_api.c
+++ b/hal/targets/hal/TARGET_STM/TARGET_STM32F3/serial_api.c
@@ -85,17 +85,25 @@ void serial_init(serial_t *obj, PinName tx, PinName rx)
 
     // Enable USART clock + switch to SystemClock
     if (obj->uart == UART_1) {
+        __USART1_FORCE_RESET();
+        __USART1_RELEASE_RESET();
         __USART1_CLK_ENABLE();
         __HAL_RCC_USART1_CONFIG(RCC_USART1CLKSOURCE_SYSCLK);
         obj->index = 0;
     }
+#if defined(USART2_BASE)
     if (obj->uart == UART_2) {
+        __USART2_FORCE_RESET();
+        __USART2_RELEASE_RESET();
         __USART2_CLK_ENABLE();
         __HAL_RCC_USART2_CONFIG(RCC_USART2CLKSOURCE_SYSCLK);
         obj->index = 1;
     }
+#endif
 #if defined(USART3_BASE)
     if (obj->uart == UART_3) {
+        __USART3_FORCE_RESET();
+        __USART3_RELEASE_RESET();
         __USART3_CLK_ENABLE();
         __HAL_RCC_USART3_CONFIG(RCC_USART3CLKSOURCE_SYSCLK);
         obj->index = 2;
@@ -103,6 +111,8 @@ void serial_init(serial_t *obj, PinName tx, PinName rx)
 #endif
 #if defined(UART4_BASE)
     if (obj->uart == UART_4) {
+        __UART4_FORCE_RESET();
+        __UART4_RELEASE_RESET();
         __UART4_CLK_ENABLE();
         __HAL_RCC_UART4_CONFIG(RCC_UART4CLKSOURCE_SYSCLK);
         obj->index = 3;
@@ -110,6 +120,8 @@ void serial_init(serial_t *obj, PinName tx, PinName rx)
 #endif
 #if defined(UART5_BASE)
     if (obj->uart == UART_5) {
+        __HAL_RCC_UART5_FORCE_RESET();
+        __HAL_RCC_UART5_RELEASE_RESET();
         __UART5_CLK_ENABLE();
         __HAL_RCC_UART5_CONFIG(RCC_UART5CLKSOURCE_SYSCLK);
         obj->index = 4;