[stm32] Add basic DMA support to F3 ADC driver

Author: chris-durand

src/modm/platform/adc/stm32f3/adc.hpp.in

@@ -290,6 +290,25 @@ public:
 %% endif
 	};
 
+	enum class DmaMode : uint32_t
+	{
+		Disabled = 0,
+%% if target["family"] in ["h7"] and resolution == 12:
+		OneShot = ADC3_CFGR_DMAEN,
+		Circular = ADC3_CFGR_DMACFG | ADC3_CFGR_DMAEN,
+		Mask = Circular
+%% elif target["family"] in ["h7"] and resolution == 16:
+		OneShot = ADC_CFGR_DMNGT_0,
+		Dfsdm = ADC_CFGR_DMNGT_1,
+		Circular = ADC_CFGR_DMNGT_1 | ADC_CFGR_DMNGT_0,
+		Mask = ADC_CFGR_DMNGT_Msk
+%% else
+		OneShot = ADC_CFGR_DMAEN,
+		Circular = ADC_CFGR_DMACFG | ADC_CFGR_DMAEN,
+		Mask = Circular
+%% endif
+	};
+
 	enum class Interrupt : uint32_t
 	{
 		Ready 								= ADC_IER_ADRDYIE,
@@ -581,6 +600,16 @@ public:
 	static inline void
 	acknowledgeInterruptFlags(const InterruptFlag_t flags);
 
+	/// @return ADC data register pointer, for DMA use only.
+	static inline volatile uint32_t*
+	dataRegister()
+	{
+		return &(ADC{{ id }}->DR);
+	}
+
+	static inline void
+	setDmaMode(DmaMode mode);
+
 private:
 	static inline bool
 	configureChannel(Channel channel, SampleTime sampleTime);

src/modm/platform/adc/stm32f3/adc_impl.hpp.in

@@ -357,6 +357,13 @@ modm::platform::Adc{{ id }}::isInjectedConversionFinished()
 	return static_cast<bool>(getInterruptFlags() & InterruptFlag::EndOfInjectedSequenceOfConversions);
 }
 
+void
+modm::platform::Adc{{ id }}::setDmaMode(DmaMode mode)
+{
+	constexpr uint32_t mask = std::to_underlying(DmaMode::Mask);
+	ADC{{ id }}->CFGR = (ADC{{ id }}->CFGR & ~mask) | std::to_underlying(mode);
+}
+
 // ----------------------------------------------------------------------------
 void
 modm::platform::Adc{{ id }}::enableInterruptVector(const uint32_t priority,