static void
rx_dma_callback(DMA_HANDLE handle, uint8_t status, void *arg)
{
/*
* We are here because DMA completed, or UART reception stopped and
* we think we have a packet in the buffer.
*/
perf_begin(pc_txns);
/* disable UART DMA */
rCR3 &= ~(USART_CR3_DMAT | USART_CR3_DMAR);
/* handle the received packet */
rx_handle_packet();
/* re-set DMA for reception first, so we are ready to receive before we start sending */
dma_reset();
/* send the reply to the just-processed request */
dma_packet.crc = 0;
dma_packet.crc = crc_packet(&dma_packet);
stm32_dmasetup(
tx_dma,
(uint32_t)&rDR,
(uint32_t)&dma_packet,
PKT_SIZE(dma_packet),
DMA_CCR_DIR |
DMA_CCR_MINC |
DMA_CCR_PSIZE_8BITS |
DMA_CCR_MSIZE_8BITS);
stm32_dmastart(tx_dma, NULL, NULL, false);
rCR3 |= USART_CR3_DMAT;
perf_end(pc_txns);
}
static void
rx_dma_callback(DMA_HANDLE handle, uint8_t status, void *arg)
{
uint16_t sr = rSR;
stm32_dmastop(rx_dma);
stm32_dmastop(tx_dma);
/* handle the received packet */
rx_handle_packet();
/* re-set DMA for reception first, so we are ready to receive before we start sending */
if (!(sr & SPI_SR_BSY)) {
dma_reset();
}
/* send the reply to the just-processed request */
dma_packet.crc = 0;
dma_packet.crc = crc_packet(&dma_packet);
stm32_dmasetup(
tx_dma,
(uint32_t)&rDR,
(uint32_t)&dma_packet,
PKT_SIZE(dma_packet),
DMA_CCR_DIR |
DMA_CCR_MINC |
DMA_CCR_PSIZE_8BITS |
DMA_CCR_MSIZE_8BITS |
DMA_CCR_PRIMED);
stm32_dmastart(tx_dma, NULL, NULL, false);
perf_end(pc_txns);
}
