HardwareTimer: Fix STM32F1 specific gpio configuration is case of input

On F1 family, input alternate function must configure GPIO in input mode
(not in alternate function like other STM32 families).

Fixes stm32duino#812

Author: ABOSTM

cores/arduino/HardwareTimer.cpp

@@ -651,8 +651,17 @@ void HardwareTimer::setMode(uint32_t channel, TimerModes_t mode, PinName pin)
 
   if (pin != NC) {
     if ((int)get_pwm_channel(pin) == timChannel) {
-      /* Configure PWM GPIO pins */
-      pinmap_pinout(pin, PinMap_PWM);
+#if defined(STM32F1xx)
+      if ((mode == TIMER_INPUT_CAPTURE_RISING) || (mode == TIMER_INPUT_CAPTURE_FALLING) \
+          || (mode == TIMER_INPUT_CAPTURE_BOTHEDGE) || (mode == TIMER_INPUT_FREQ_DUTY_MEASUREMENT)) {
+        // on F1 family, input alternate function must configure GPIO in input mode
+        pinMode(pin, INPUT);
+      } else
+#endif
+      {
+        /* Configure PWM GPIO pins */
+        pinmap_pinout(pin, PinMap_PWM);
+      }
     } else {
       // Pin doesn't match with timer output channels
       Error_Handler();