[dma] Support double buffer (only stm32-stream-channel)

Author: rleh

src/modm/platform/dma/stm32/dma.hpp.in

@@ -137,10 +137,18 @@ public:
 				MemoryIncrementMode memoryIncrement,
 				PeripheralIncrementMode peripheralIncrement,
 				Priority priority = Priority::Medium,
-				CircularMode circularMode = CircularMode::Disabled)
+				CircularMode circularMode = CircularMode::Disabled
+%% if doubleBuffer
+				,DoubleBufferMode doubleBufferMode = DoubleBufferMode::Disabled
+%% endif
+				)
 		{
-			ChannelHal::configure(direction, memoryDataSize, peripheralDataSize,
-					memoryIncrement, peripheralIncrement, priority, circularMode);
+			ChannelHal::configure(direction, memoryDataSize, peripheralDataSize, memoryIncrement,
+								  peripheralIncrement, priority, circularMode
+%% if doubleBuffer
+								  , doubleBufferMode
+%% endif
+								  );
 		}
 
 		/**
@@ -183,6 +191,33 @@ public:
 		{
 			ChannelHal::setMemoryAddress(address);
 		}
+
+%% if doubleBuffer
+		/**
+		 * Set the secondary memory address of the DMA channel
+		 *
+		 * Only used in double buffer mode
+		 *
+		 * @param[in] address Source address
+		 */
+		static void
+		setMemoryAddress2(uintptr_t address)
+		{
+			ChannelHal::setMemoryAddress2(address);
+		}
+
+		/**
+		 * Detect which buffer is currently in use
+		 *
+		 * Only meaningful in double buffer mode
+		 */
+		static bool
+		isPrimaryBufferActive()
+		{
+			return ChannelHal::isPrimaryBufferActive();
+		}
+%% endif
+
 		/**
 		 * Set the peripheral address of the DMA channel
 		 *

src/modm/platform/dma/stm32/dma_base.hpp.in

@@ -196,6 +196,15 @@ public:
 		Enabled 	= {{ reg_prefix }}_CIRC, ///< circular mode
 	};
 
+%% if doubleBuffer
+	enum class
+	DoubleBufferMode : uint32_t
+	{
+		Disabled 	= 0,
+		Enabled 	= {{ reg_prefix }}_DBM, ///< double buffer mode
+	};
+%% endif
+
 	enum class
 	DataTransferDirection : uint32_t
 	{

src/modm/platform/dma/stm32/dma_hal.hpp.in

@@ -181,20 +181,29 @@ public:
 	 * @param[in] circularMode Transfer data in circular mode?
 	 */
 	static void
-	configure(DataTransferDirection direction, MemoryDataSize memoryDataSize,
-			PeripheralDataSize peripheralDataSize,
-			MemoryIncrementMode memoryIncrement,
-			PeripheralIncrementMode peripheralIncrement,
-			Priority priority = Priority::Medium,
-			CircularMode circularMode = CircularMode::Disabled)
+	configure(DataTransferDirection direction,
+			  MemoryDataSize memoryDataSize,
+			  PeripheralDataSize peripheralDataSize,
+			  MemoryIncrementMode memoryIncrement,
+			  PeripheralIncrementMode peripheralIncrement,
+			  Priority priority = Priority::Medium,
+			  CircularMode circularMode = CircularMode::Disabled
+%% if doubleBuffer
+			  , DoubleBufferMode doubleBufferMode = DoubleBufferMode::Disabled
+%% endif
+			  )
 	{
 		stop();
 
 		DMA_Channel_TypeDef *Base = (DMA_Channel_TypeDef *) CHANNEL_BASE;
 		Base->{{ cr }} = uint32_t(direction) | uint32_t(memoryDataSize) |
 				uint32_t(peripheralDataSize) | uint32_t(memoryIncrement) |
 				uint32_t(peripheralIncrement) | uint32_t(priority) |
-				uint32_t(circularMode);
+				uint32_t(circularMode)
+%% if doubleBuffer
+				| uint32_t(doubleBufferMode)
+%% endif
+				;
 	}
 
 	/**
@@ -236,6 +245,38 @@ public:
 %% endif
 	}
 
+%% if doubleBuffer
+	/**
+	 * Set the secondary memory address of the DMA channel
+	 *
+	 * Only used in double buffer mode
+	 *
+	 * @param[in] address Source address
+	 */
+	static void
+	setMemoryAddress2(uintptr_t address)
+	{
+		DMA_Channel_TypeDef *Base = (DMA_Channel_TypeDef *) CHANNEL_BASE;
+%% if dmaType in ["stm32-stream-channel"]
+		Base->M1AR = address;
+%% endif
+	}
+
+	/**
+	 * Detect which buffer is currently in use
+	 *
+	 * Only meaningful in double buffer mode
+	 */
+	static bool
+	isPrimaryBufferActive()
+	{
+		DMA_Channel_TypeDef *Base = (DMA_Channel_TypeDef *) CHANNEL_BASE;
+%% if dmaType in ["stm32-stream-channel"]
+		return (Base->CR & DMA_SxCR_CT);
+%% endif
+	}
+%% endif
+
 	/**
 	 * Set the peripheral address of the DMA channel
 	 *

src/modm/platform/dma/stm32/module.lb

@@ -186,6 +186,7 @@ def build(env):
     properties["dmaType"] = dma["type"]
     properties["dmaSignals"] = signal_names
     properties["dmaController"] = controller
+    properties["doubleBuffer"] = (dma["type"] in ["stm32-stream-channel"]) ## TODO: which other types support double buffer mode?
 
     properties['channel_count'] = {
         "min" : min(controller, key=lambda c: c["min_channel"])["min_channel"],