bool result;
int result_i;
void dma_callback_test(void * args) {
*((uint8_t *)args) = 0;
}
msp430x_dma_req_t test_1_req = {
instring, /* source address */
outstring, /* destination address */
9, /* number of words */
MSP430X_DMA_SRCINCR | MSP430X_DMA_DSTINCR, /* address mode - dual increment */
MSP430X_DMA_SRCWORD | MSP430X_DMA_DSTWORD, /* word transfer */
MSP430X_DMA_BLOCK, /* block (and blocking) transfer */
DMA_TRIGGER_MNEM(DMAREQ), /* software-requested trigger */
{
NULL, /* no callback */
NULL /* no arguments */
}
};
msp430x_dma_req_t test_2_req = {
instring, /* source address */
outstring, /* destination address */
18, /* number of bytes */
MSP430X_DMA_SRCINCR | MSP430X_DMA_DSTINCR, /* address mode - dual increment */
MSP430X_DMA_SRCBYTE | MSP430X_DMA_DSTBYTE, /* byte transfer */
MSP430X_DMA_BLOCK, /* block (and blocking) transfer */
DMA_TRIGGER_MNEM(DMAREQ), /* software-requested trigger */
{
/**
* @brief Requests a DMA transfer operation from the DMA engine.
* @note The DMA engine uses unclaimed DMA channels to provide DMA services
* for one-off or infrequent uses. If all channels are busy, and
* semaphores are enabled, the calling thread will sleep until a
* channel is available or the request times out. If semaphores are
* disabled, the calling thread will busy-wait instead of sleeping.
*/
bool dmaRequest(msp430x_dma_req_t * request, systime_t timeout) {
/* Check if a DMA channel is available */
#if CH_CFG_USE_SEMAPHORES
msg_t semresult = chSemWaitTimeout(&dma_lock, timeout);
if (semresult != MSG_OK)
return true;
#endif
#if !(CH_CFG_USE_SEMAPHORES)
systime_t start = chVTGetSystemTimeX();
do {
#endif
/* Grab the correct DMA channel to use */
int i = 0;
for (i = 0; i < MSP430X_DMA_CHANNELS; i++) {
if (!(dma_channels[i].ctl & DMAEN)) {
break;
}
}
#if !(CH_CFG_USE_SEMAPHORES)
while (chVTTimeElapsedSinceX(start) < timeout)
;
#endif
#if !(CH_CFG_USE_SEMAPHORES)
if (i == MSP430X_DMA_CHANNELS) {
return true;
}
#endif
/* Make the request */
init_request(request, i);
return false;
}
/**
* @brief Acquires exclusive control of a DMA channel.
* @pre The channel must not be already acquired or an error is returned.
* @note If the channel is in use by the DMA engine, blocks until acquired.
* @post This channel must be interacted with using only the functions
* defined in this module.
*
* @param[out] channel The channel handle. Must be pre-allocated.
* @param[in] index The index of the channel (< MSP430X_DMA_CHANNELS).
* @return The operation status.
* @retval false no error, channel acquired.
* @retval true error, channel already acquired.
*/
bool dmaAcquire(msp430x_dma_ch_t * channel, uint8_t index) {
/* Acquire the channel in an idle mode */
/* Is the channel already acquired? */
osalDbgAssert(index < MSP430X_DMA_CHANNELS, "invalid channel index");
if (dma_channels[index].ctl & DMADT_4) {
return true;
}
/* Increment the DMA counter */
#if CH_CFG_USE_SEMAPHORES
msg_t semresult = chSemWait(&dma_lock);
if (semresult != MSG_OK)
return true;
#endif
while (dma_channels[index].ctl & DMAEN)
;
dma_trigger_set(index, DMA_TRIGGER_MNEM(DMAREQ));
dma_channels[index].sz = 0;
dma_channels[index].ctl = DMAEN | DMAABORT | DMADT_4;
channel->registers = dma_channels + index;
channel->index = index;
channel->cb = callbacks + index;
return false;
}