diff options
Diffstat (limited to 'nuttx/arch/arm/src/stm32/stm32f10xxx_dma.c')
-rw-r--r-- | nuttx/arch/arm/src/stm32/stm32f10xxx_dma.c | 56 |
1 files changed, 47 insertions, 9 deletions
diff --git a/nuttx/arch/arm/src/stm32/stm32f10xxx_dma.c b/nuttx/arch/arm/src/stm32/stm32f10xxx_dma.c index 89b279bea..13324b8ac 100644 --- a/nuttx/arch/arm/src/stm32/stm32f10xxx_dma.c +++ b/nuttx/arch/arm/src/stm32/stm32f10xxx_dma.c @@ -303,13 +303,13 @@ static int stm32_dmainterrupt(int irq, void *context) } dmach = &g_dma[chndx]; - /* Get the interrupt status (for this channel only) -- not currently used */ + /* Get the interrupt status (for this channel only) */ isr = dmabase_getreg(dmach, STM32_DMA_ISR_OFFSET) & DMA_ISR_CHAN_MASK(dmach->chan); - /* Disable the DMA channel */ + /* Clear the interrupts we are handling */ - stm32_dmachandisable(dmach); + dmabase_putreg(dmach, STM32_DMA_IFCR_OFFSET, isr); /* Invoke the callback */ @@ -528,14 +528,34 @@ void stm32_dmastart(DMA_HANDLE handle, dma_callback_t callback, void *arg, bool ccr = dmachan_getreg(dmach, STM32_DMACHAN_CCR_OFFSET); ccr |= DMA_CCR_EN; - /* Once half of the bytes are transferred, the half-transfer flag (HTIF) is - * set and an interrupt is generated if the Half-Transfer Interrupt Enable - * bit (HTIE) is set. At the end of the transfer, the Transfer Complete Flag - * (TCIF) is set and an interrupt is generated if the Transfer Complete - * Interrupt Enable bit (TCIE) is set. + /* In normal mode, interrupt at either half or full completion. In circular mode, + * always interrupt on buffer wrap, and optionally interrupt at the halfway point. */ - ccr |= (half ? (DMA_CCR_HTIE|DMA_CCR_TEIE) : (DMA_CCR_TCIE|DMA_CCR_TEIE)); + if ((ccr & DMA_CCR_CIRC) == 0) + { + /* Once half of the bytes are transferred, the half-transfer flag (HTIF) is + * set and an interrupt is generated if the Half-Transfer Interrupt Enable + * bit (HTIE) is set. At the end of the transfer, the Transfer Complete Flag + * (TCIF) is set and an interrupt is generated if the Transfer Complete + * Interrupt Enable bit (TCIE) is set. + */ + + ccr |= (half ? (DMA_CCR_HTIE|DMA_CCR_TEIE) : (DMA_CCR_TCIE|DMA_CCR_TEIE)); + + } + else + { + /* In nonstop mode, when the transfer completes it immediately resets + * and starts again. The transfer-complete interrupt is thus always + * enabled, and the half-complete interrupt can be used in circular + * mode to determine when the buffer is half-full, or in double-buffered + * mode to determine when one of the two buffers is full. + */ + + ccr |= (half ? DMA_CCR_HTIE : 0) | DMA_CCR_TCIE | DMA_CCR_TEIE; + } + dmachan_putreg(dmach, STM32_DMACHAN_CCR_OFFSET, ccr); } @@ -559,6 +579,24 @@ void stm32_dmastop(DMA_HANDLE handle) } /**************************************************************************** + * Name: stm32_dmaresidual + * + * Description: + * Returns the number of bytes remaining to be transferred + * + * Assumptions: + * - DMA handle allocated by stm32_dmachannel() + * + ****************************************************************************/ + +size_t stm32_dmaresidual(DMA_HANDLE handle) +{ + struct stm32_dma_s *dmach = (struct stm32_dma_s *)handle; + + return dmachan_getreg(dmach, STM32_DMACHAN_CNDTR_OFFSET); +} + +/**************************************************************************** * Name: stm32_dmasample * * Description: |