From e503b95358f84eaf587565bd612a0872f453739a Mon Sep 17 00:00:00 2001
From: Fabrizio Monti <fabrizio.monti@skywarder.eu>
Date: Thu, 6 Feb 2025 20:13:40 +0100
Subject: [PATCH] [DMA] Added method to change the transaction size without the
need to rerun the entire setup.
---
src/shared/drivers/dma/DMA.cpp | 10 +++++++++-
src/shared/drivers/dma/DMA.h | 7 +++++++
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/src/shared/drivers/dma/DMA.cpp b/src/shared/drivers/dma/DMA.cpp
index 5ee1dc131..07679e4f9 100644
--- a/src/shared/drivers/dma/DMA.cpp
+++ b/src/shared/drivers/dma/DMA.cpp
@@ -370,7 +370,8 @@ void DMAStream::setup(DMATransaction transaction)
registers->CR |= static_cast<uint32_t>(transaction.priority);
if (transaction.circularMode)
registers->CR |= DMA_SxCR_CIRC;
- registers->NDTR = transaction.numberOfDataItems;
+
+ setNumberOfDataItems(transaction.numberOfDataItems);
if (transaction.direction == DMATransaction::Direction::MEM_TO_PER)
{
@@ -551,6 +552,13 @@ void DMAStream::readFlags()
directModeErrorFlag = flags & DMA_LISR_DMEIF0;
}
+void DMAStream::setNumberOfDataItems(const uint16_t nBytes)
+{
+ // TODO: assert that the stream is disabled while doing it
+ currentSetup.numberOfDataItems = nBytes;
+ registers->NDTR = nBytes;
+}
+
int DMAStream::getCurrentBufferNumber()
{
return (registers->CR & DMA_SxCR_CT) != 0 ? 2 : 1;
diff --git a/src/shared/drivers/dma/DMA.h b/src/shared/drivers/dma/DMA.h
index e36a70d90..8fda416db 100644
--- a/src/shared/drivers/dma/DMA.h
+++ b/src/shared/drivers/dma/DMA.h
@@ -210,6 +210,13 @@ public:
*/
void readFlags();
+ /**
+ * @brief Set the number of bytes to be exchanged during a
+ * dma transaction. Useful in case you don't want to change
+ * the entire configuration.
+ */
+ void setNumberOfDataItems(const uint16_t nBytes);
+
/**
* @brief Returns the last read status of the half transfer flag.
*
--
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