[stm32] [timer] Add getClockFrequency()

When using the timer as a template parameter, there is no other way to
get the clock frequency at which a timer is running. This is required
for some userspace calculations for prescaler and overflow.

Author: strongly-typed

src/modm/platform/timer/stm32/advanced.hpp.in

@@ -170,6 +170,13 @@ public:
 		return TIM{{ id }}->ARR;
 	}
 
+	template<class SystemClock>
+	static constexpr uint32_t
+	getClockFrequency()
+	{
+		return SystemClock::Timer{{ id }};
+	}
+
 	template<class SystemClock, class Rep, class Period>
 	static Value
 	setPeriod(std::chrono::duration<Rep, Period> duration, bool autoApply = true)

src/modm/platform/timer/stm32/basic.hpp.in

@@ -111,6 +111,13 @@ public:
 		return TIM{{ id }}->ARR;
 	}
 
+	template<class SystemClock>
+	static constexpr uint32_t
+	getClockFrequency()
+	{
+		return SystemClock::Timer{{ id }};
+	}
+
 	template<class SystemClock, class Rep, class Period>
 	static Value
 	setPeriod(std::chrono::duration<Rep, Period> duration, bool autoApply = true)

src/modm/platform/timer/stm32/general_purpose.hpp.in

@@ -184,6 +184,13 @@ public:
 		return TIM{{ id }}->ARR;
 	}
 
+	template<class SystemClock>
+	static constexpr uint32_t
+	getClockFrequency()
+	{
+		return SystemClock::Timer{{ id }};
+	}
+
 	template<class SystemClock, class Rep, class Period>
 	static Value
 	setPeriod(std::chrono::duration<Rep, Period> duration, bool autoApply = true)