/**
* Reset both TX and RX channels of a DMA engine.
*
* Any DMA transaction in progress aborts immediately. The DMA engine is in
* stop state after the reset.
*
* @param InstancePtr is a pointer to the DMA engine instance to be worked on.
*
* @return None.
*
* @note
* - If the hardware is not working properly, this function will enter
* infinite loop and never return.
* - After the reset, the Normal mode is enabled, and the overflow error
* for both TX/RX channels are disabled.
* - After the reset, the DMA engine is no longer in pausing state, if
* the DMA engine is paused before the reset operation.
* - After the reset, the coalescing count value and the delay timeout
* value are both set to 1 for TX and RX channels.
* - After the reset, all interrupts are disabled.
*
******************************************************************************/
void XLlDma_Reset(XLlDma * InstancePtr)
{
u32 IrqStatus;
XLlDma_BdRing *TxRingPtr, *RxRingPtr;
TxRingPtr = &XLlDma_mGetTxRing(InstancePtr);
RxRingPtr = &XLlDma_mGetRxRing(InstancePtr);
/* Save the locations of current BDs both rings are working on
* before the reset so later we can resume the rings smoothly.
*/
XLlDma_mBdRingSnapShotCurrBd(TxRingPtr);
XLlDma_mBdRingSnapShotCurrBd(RxRingPtr);
/* Start reset process then wait for completion */
XLlDma_mSetCr(InstancePtr, XLLDMA_DMACR_SW_RESET_MASK);
/* Loop until the reset is done */
while ((XLlDma_mGetCr(InstancePtr) & XLLDMA_DMACR_SW_RESET_MASK)) {
}
/* Disable all interrupts after issue software reset */
XLlDma_mBdRingIntDisable(TxRingPtr, XLLDMA_CR_IRQ_ALL_EN_MASK);
XLlDma_mBdRingIntDisable(RxRingPtr, XLLDMA_CR_IRQ_ALL_EN_MASK);
/* Clear Interrupt registers of both channels, as the software reset
* does not clear any register values. Not doing so will cause
* interrupts asserted after the software reset if there is any
* interrupt left over before.
*/
IrqStatus = XLlDma_mBdRingGetIrq(TxRingPtr);
XLlDma_mBdRingAckIrq(TxRingPtr, IrqStatus);
IrqStatus = XLlDma_mBdRingGetIrq(RxRingPtr);
XLlDma_mBdRingAckIrq(RxRingPtr, IrqStatus);
/* Enable Normal mode, and disable overflow errors for both channels */
XLlDma_mSetCr(InstancePtr, XLLDMA_DMACR_TAIL_PTR_EN_MASK |
XLLDMA_DMACR_RX_OVERFLOW_ERR_DIS_MASK |
XLLDMA_DMACR_TX_OVERFLOW_ERR_DIS_MASK);
/* Set TX/RX Channel coalescing setting */
XLlDma_BdRingSetCoalesce(TxRingPtr, 1, 1);
XLlDma_BdRingSetCoalesce(RxRingPtr, 1, 1);
TxRingPtr->RunState = XST_DMA_SG_IS_STOPPED;
RxRingPtr->RunState = XST_DMA_SG_IS_STOPPED;
}
/**
*
* This is the DMA TX callback function to be called by TX interrupt handler.
* This function handles BDs finished by hardware.
*
* @param TxRingPtr is a pointer to TX channel of the DMA engine.
*
* @return None.
*
* @note None.
*
******************************************************************************/
static void TxCallBack(XLlDma_BdRing * TxRingPtr)
{
/*
* Disable the transmit related interrupts
*/
XLlDma_mBdRingIntDisable(TxRingPtr, XLLDMA_CR_IRQ_ALL_EN_MASK);
/*
* Increment the counter so that main thread knows something happened
*/
FramesTx++;
}
