/**
* @brief Sets the number of transfers to be performed.
* @note This function can be invoked in both ISR or thread context.
*
* @pre The channel must have been allocated using @p dmaChannelAllocate().
* @post After use the channel can be released using @p dmaChannelRelease().
*
* @param[in] dmastp pointer to a sama_dma_channel_t structure
* @param[in] size value to be written in the XDMAC_CUBC register
*
* @special
*
*/
void dmaChannelSetTransactionSize(sama_dma_channel_t *dmachp, size_t n) {
uint32_t i;
uint32_t divisor;
/* Single block single microblock */
if (n <= XDMAC_MAX_BT_SIZE) {
(dmachp)->xdmac->XDMAC_CHID[(dmachp)->chid].XDMAC_CUBC = XDMAC_CUBC_UBLEN(n);
}
/* Single block multiple microblocks */
else {
/* If n exceeds XDMAC_MAX_BT_SIZE, split the transfer in microblocks */
for (i = 2; i < XDMAC_MAX_BT_SIZE; i++) {
divisor = XDMAC_MAX_BT_SIZE / i;
if (n % divisor)
continue;
if ((n / divisor) <= (XDMAC_MAX_BLOCK_LEN + 1)) {
(dmachp)->xdmac->XDMAC_CHID[(dmachp)->chid].XDMAC_CUBC = XDMAC_CUBC_UBLEN(i);
(dmachp)->xdmac->XDMAC_CHID[(dmachp)->chid].XDMAC_CBC =
XDMAC_CBC_BLEN((n / divisor) - 1);
break;
}
}
osalDbgAssert(i != XDMAC_MAX_BT_SIZE, "unsupported DMA transfer size");
}
}
/**
* \brief Set block length for the relevant channel of given XDMA.
*
* \param pXdmac Pointer to the XDMAC peripheral.
* \param channel Particular channel number.
* \param blen Block length.
*/
void XDMAC_SetBlockControl(Xdmac *pXdmac, uint8_t channel, uint16_t blen)
{
assert(pXdmac);
assert(channel < XDMAC_CHANNEL_NUM);
pXdmac->XDMAC_CHID[channel].XDMAC_CBC = XDMAC_CBC_BLEN(blen);
}
