From 1f0216d9d141917b7c612b14f7948f5fa09aa87f Mon Sep 17 00:00:00 2001
From: Fabrizio Monti <fabrizio.monti@skywarder.eu>
Date: Tue, 4 Mar 2025 08:45:08 +0100
Subject: [PATCH] [DMA] Added documentation and small code refactoring (removed
unnecessary member variable and made DMAStreamId constant inside DMAStream).
---
src/shared/drivers/dma/DMA.cpp | 5 ++---
src/shared/drivers/dma/DMA.h | 39 ++++++++++++++++++++++++++++++----
2 files changed, 37 insertions(+), 7 deletions(-)
diff --git a/src/shared/drivers/dma/DMA.cpp b/src/shared/drivers/dma/DMA.cpp
index ecd258978..c23edfe84 100644
--- a/src/shared/drivers/dma/DMA.cpp
+++ b/src/shared/drivers/dma/DMA.cpp
@@ -507,6 +507,8 @@ void DMAStream::setup(DMATransaction& transaction)
enableInterrupt = true;
}
+ // Select the interrupt number
+ IRQn_Type irqNumber = DMADefs::irqNumberMapping[static_cast<uint8_t>(id)];
if (enableInterrupt)
{
NVIC_SetPriority(irqNumber, 8);
@@ -674,9 +676,6 @@ DMAStream::DMAStream(DMADefs::DMAStreamId id, DMADefs::Channel channel)
// Refer to reference manual for the register bits structure
int offset = static_cast<uint8_t>(id) % 4;
IFindex = (offset % 2) * 6 + (offset / 2) * 16;
-
- // Select the interrupt
- irqNumber = DMADefs::irqNumberMapping[static_cast<uint8_t>(id)];
}
DMAStream* DMAStreamGuard::operator->()
diff --git a/src/shared/drivers/dma/DMA.h b/src/shared/drivers/dma/DMA.h
index 1d78927b7..4234aa342 100644
--- a/src/shared/drivers/dma/DMA.h
+++ b/src/shared/drivers/dma/DMA.h
@@ -89,6 +89,9 @@ public:
static DMADriver& instance();
+ /**
+ * @return True if the stream is not already in use.
+ */
bool tryChannel(DMADefs::DMAStreamId id);
/**
@@ -123,6 +126,9 @@ public:
private:
DMADriver();
+ /**
+ * @brief Wakeup the sleeping thread associated to the stream.
+ */
void IRQwakeupThread(DMAStream& stream);
miosix::FastMutex mutex;
@@ -146,18 +152,44 @@ public:
/**
* @brief Activate the stream. As soon as the stream is enabled, it
- * can serve any DMA request from the peripheral connected to the stream.
+ * serves any DMA request from/to the peripheral connected to the stream.
*/
void enable();
void disable();
+ /**
+ * @brief Wait for the half transfer complete signal.
+ * The caller waits for the corresponding interrupt, if enabled.
+ * Otherwise it goes to polling mode on the flag.
+ */
void waitForHalfTransfer();
+ /**
+ * @brief Wait for the transfer complete signal.
+ * The caller waits for the corresponding interrupt, if enabled.
+ * Otherwise it goes to polling mode on the flag.
+ */
void waitForTransferComplete();
+ /**
+ * @brief Wait for the half transfer complete signal.
+ * The caller waits for the corresponding interrupt, if enabled.
+ * Otherwise it goes to polling mode on the flag.
+ * @param timeout_ns The maximum time that will be waited.
+ * @return True if the event is reached, false if the
+ * timeout expired.
+ */
bool timedWaitForHalfTransfer(std::chrono::nanoseconds timeout_ns);
+ /**
+ * @brief Wait for the transfer complete signal.
+ * The caller waits for the corresponding interrupt, if enabled.
+ * Otherwise it goes to polling mode on the flag.
+ * @param timeout_ns The maximum time that will be waited.
+ * @return True if the event is reached, false if the
+ * timeout expired.
+ */
bool timedWaitForTransferComplete(std::chrono::nanoseconds timeout_ns);
void setHalfTransferCallback(std::function<void()> callback);
@@ -278,7 +310,7 @@ private:
/**
* @brief Used to determine if the user thread is
- * waiting to be awaked by an interrupt.
+ * waiting to be awakened by an interrupt.
*/
miosix::Thread* waitingThread = nullptr;
@@ -294,9 +326,8 @@ private:
std::function<void()> transferCompleteCallback;
std::function<void()> errorCallback;
- DMADefs::DMAStreamId id;
+ const DMADefs::DMAStreamId id;
DMADefs::Channel currentChannel;
- IRQn_Type irqNumber;
DMA_Stream_TypeDef* registers;
volatile uint32_t* ISR; ///< Interrupt status register
--
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