SPI DMA cleanup

Author: stevstrong

STM32F4/libraries/SPI/src/SPI.cpp

@@ -428,14 +428,13 @@ uint8 SPIClass::dmaTransfer(void * transmitBuf, void * receiveBuf, uint16 length
 	);
 	dma_set_num_transfers(_currentSetting->spiDmaDev, _currentSetting->spiRxDmaStream, length);
 	dma_set_fifo_flags(_currentSetting->spiDmaDev, _currentSetting->spiRxDmaStream, 0);
-	dma_clear_isr_bits(_currentSetting->spiDmaDev, _currentSetting->spiRxDmaStream);
 
 	// TX
-	uint32 flags = (DMA_MINC_MODE | DMA_FROM_MEM); // | DMA_TRNS_CMPLT);
+	uint32 flags = (DMA_MINC_MODE | DMA_FROM_MEM);
 	if ( transmitBuf==0 ) {
-		static uint8_t ff = 0XFF;
+		static uint16_t ff = 0XFFFF;
 		transmitBuf = &ff;
-		flags &= ~((uint32)DMA_MINC_MODE); // remove increment mode
+		flags ^= DMA_MINC_MODE; // remove increment mode
 	}
 	dma_setup_transfer(	_currentSetting->spiDmaDev,
 						_currentSetting->spiTxDmaStream,
@@ -457,19 +456,18 @@ uint8 SPIClass::dmaTransfer(void * transmitBuf, void * receiveBuf, uint16 length
 	spi_tx_dma_enable(_currentSetting->spi_d);	// must be the last enable to avoid DMA error flag
 
     uint32_t m = millis();
-	while ((b = dma_get_isr_bits(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaStream) & DMA_ISR_TCIF)==0 ) {// wait for completion flag to be set
-		if ( b&(DMA_ISR_TEIF|DMA_ISR_DMEIF|DMA_ISR_FEIF) ) { b = 1; break; } // break on any error flag
+	while ((dma_get_isr_bits(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaStream) & DMA_ISR_TCIF)==0 ) {// wait for completion flag to be set
 		if ((millis() - m) > DMA_TIMEOUT) { b = 2; break; }
     }
-	if (b & DMA_ISR_TCIF) b = 0;
 
 	while (spi_is_tx_empty(_currentSetting->spi_d) == 0); // "5. Wait until TXE=1 ..."
 	while (spi_is_busy(_currentSetting->spi_d) != 0); // "... and then wait until BSY=0 before disabling the SPI." 
 	// software disable sequence, see AN4031, chapter 4.1
 	spi_tx_dma_disable(_currentSetting->spi_d);
 	spi_rx_dma_disable(_currentSetting->spi_d);
+	dma_disable(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaStream);
 	dma_disable(_currentSetting->spiDmaDev, _currentSetting->spiRxDmaStream);
-    dma_disable(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaStream);
+
     return b;
 }
 
@@ -502,11 +500,9 @@ uint8 SPIClass::dmaSend(void * transmitBuf, uint16 length, bool minc)
 	spi_tx_dma_enable(_currentSetting->spi_d);
 
 	uint32_t m = millis();
-	while ((b = dma_get_isr_bits(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaStream) & DMA_ISR_TCIF)==0 ) {// wait for completion flag to be set
-		if ( b&(DMA_ISR_TEIF|DMA_ISR_DMEIF|DMA_ISR_FEIF) ) { b = 1; break; } // break on any error flag
+	while ((dma_get_isr_bits(_currentSetting->spiDmaDev, _currentSetting->spiTxDmaStream) & DMA_ISR_TCIF)==0 ) {// wait for completion flag to be set
 		if ((millis() - m) > DMA_TIMEOUT) { b = 2; break; }
     }
-	if (b & DMA_ISR_TCIF) b = 0;
 
 	while (spi_is_tx_empty(_currentSetting->spi_d) == 0); // "5. Wait until TXE=1 ..."
 	while (spi_is_busy(_currentSetting->spi_d) != 0); // "... and then wait until BSY=0 before disabling the SPI."