Merge pull request #2022 from whj4674672/master

[BSP]stm32f107 fix usart3

bsp/stm32f107/drivers/usart.c

@@ -59,19 +59,19 @@ static rt_err_t stm32_configure(struct rt_serial_device *serial, struct serial_c
 
     USART_InitStructure.USART_BaudRate = cfg->baud_rate;
 
-    if (cfg->data_bits == DATA_BITS_8){
+    if (cfg->data_bits == DATA_BITS_8) {
         USART_InitStructure.USART_WordLength = USART_WordLength_8b;
     } else if (cfg->data_bits == DATA_BITS_9) {
         USART_InitStructure.USART_WordLength = USART_WordLength_9b;
     }
 
-    if (cfg->stop_bits == STOP_BITS_1){
+    if (cfg->stop_bits == STOP_BITS_1) {
         USART_InitStructure.USART_StopBits = USART_StopBits_1;
-    } else if (cfg->stop_bits == STOP_BITS_2){
+    } else if (cfg->stop_bits == STOP_BITS_2) {
         USART_InitStructure.USART_StopBits = USART_StopBits_2;
     }
 
-    if (cfg->parity == PARITY_NONE){
+    if (cfg->parity == PARITY_NONE) {
         USART_InitStructure.USART_Parity = USART_Parity_No;
     } else if (cfg->parity == PARITY_ODD) {
         USART_InitStructure.USART_Parity = USART_Parity_Odd;
@@ -295,6 +295,7 @@ static void RCC_Configuration(void)
 
 #if defined(RT_USING_UART3)
     RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOC, ENABLE);
+    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3,ENABLE);
     GPIO_PinRemapConfig(GPIO_PartialRemap_USART3, ENABLE);
 #endif /* RT_USING_UART3 */
 }