STM32 I2C manage STOP specific case

In case the user applicaiton makes a mixed usage of unitary function
(start, stop, byte write & read) with SYNC operation (write and read of
data buffers with start and stop management), we need to reset the
STM32 HAL state as it is by-passed by a direct call to STOP

Author: LMESTM

targets/TARGET_STM/i2c_api.c

@@ -483,10 +483,18 @@ int i2c_start(i2c_t *obj) {
 int i2c_stop(i2c_t *obj) {
     struct i2c_s *obj_s = I2C_S(obj);
     I2C_TypeDef *i2c = (I2C_TypeDef *)obj_s->i2c;
+    I2C_HandleTypeDef *handle = &(obj_s->handle);
+    int timeout;
 
     // Generate the STOP condition
     i2c->CR1 |= I2C_CR1_STOP;
 
+    /*  In case of mixed usage of the APIs (unitary + SYNC)
+     *  re-inti HAL state
+     */
+    if(obj_s->XferOperation != I2C_FIRST_AND_LAST_FRAME)
+            i2c_init(obj, obj_s->sda, obj_s->scl);
+
     return 0;
 }