STM32: RESET GPIO during init is configurable

Default value is disabled

targets/TARGET_STM/mbed_overrides.c

@@ -94,6 +94,7 @@ MBED_WEAK void TargetBSP_Init(void) {
     /** Do nothing */
 }
 
+#if MBED_CONF_TARGET_GPIO_RESET_AT_INIT
 void GPIO_Full_Init(void) {
     GPIO_InitTypeDef GPIO_InitStruct;
 
@@ -160,6 +161,7 @@ void GPIO_Full_Init(void) {
     __HAL_RCC_GPIOK_CLK_DISABLE();
 #endif
 }
+#endif
 
 // This function is called after RAM initialization and before main.
 void mbed_sdk_init()
@@ -309,8 +311,10 @@ void mbed_sdk_init()
 #endif /* ! MBED_CONF_TARGET_LSE_AVAILABLE */
 #endif /* DEVICE_RTC */
 
+#if MBED_CONF_TARGET_GPIO_RESET_AT_INIT
     /* Reset all GPIO */
     GPIO_Full_Init();
+#endif
 
     /* BSP initialization hook (external RAM, etc) */
     TargetBSP_Init();

targets/targets.json

@@ -1157,6 +1157,10 @@
             "lpticker_lptim_clock": {
                 "help": "Default value for LPTIM clock (lpticker_lptim == 1). Value is the dividing factor. Choose 1, 2 or 4",
                 "value": 1
+            },
+            "gpio_reset_at_init": {
+                "help": "if value set, all GPIO are reset during init",
+                "value": false
             }
         },
         "overrides": {
@@ -3200,6 +3204,9 @@
                 "macro_name": "CLOCK_SOURCE"
             }
         },
+        "overrides": {
+            "gpio_reset_at_init": true
+        },
         "device_has_add": [
             "ANALOGOUT",
             "SERIAL_ASYNCH",