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mimxrt/machine_spi: Improve handling of busy SPI peripheral.

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This commit changes the method of waiting for SPI being not busy.  Instead
of the FIFO size, the TransferBusyFlag is probed.

Also, raise an error if the transfer failed.
This commit is contained in:
robert-hh 2022-03-20 13:20:10 +01:00 committed by Damien George
parent b70b8ce3e4
commit 752fe75910
1 changed files with 18 additions and 10 deletions
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28
ports/mimxrt/machine_spi.c
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@ -277,6 +277,10 @@ STATIC void machine_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint8
LPSPI_MasterTransferCreateHandleEDMA(self->spi_inst, &g_master_edma_handle, LPSPI_EDMAMasterCallback, self,
&lpspiEdmaMasterRxRegToRxDataHandle,
&lpspiEdmaMasterTxDataToTxRegHandle);
// Wait a short while for a previous transfer to finish, but not forever
for (volatile int j = 0; (j < 5000) && ((LPSPI_GetStatusFlags(self->spi_inst) & kLPSPI_ModuleBusyFlag) != 0); j++) {}
// Start master transfer
lpspi_transfer_t masterXfer;
masterXfer.txData = (uint8_t *)src;
@ -297,12 +301,15 @@ STATIC void machine_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint8
} else if (src) {
DCACHE_CleanByRange((uint32_t)src, len);
}
LPSPI_MasterTransferEDMA(self->spi_inst, &g_master_edma_handle, &masterXfer);
while (self->transfer_busy) {
MICROPY_EVENT_POLL_HOOK
if (LPSPI_MasterTransferEDMA(self->spi_inst, &g_master_edma_handle, &masterXfer) != kStatus_Success) {
L1CACHE_EnableDCache();
mp_raise_OSError(EIO);
} else {
while (self->transfer_busy) {
MICROPY_EVENT_POLL_HOOK
}
L1CACHE_EnableDCache();
}
L1CACHE_EnableDCache();
}
// Release DMA channels, even if never allocated.
if (chan_rx >= 0) {
@ -313,10 +320,9 @@ STATIC void machine_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint8
}
if (!use_dma) {
// Wait until a previous Transfer is finished
while (LPSPI_GetTxFifoCount(self->spi_inst) > 0) {
MICROPY_EVENT_POLL_HOOK
}
// Wait a short while for a previous transfer to finish, but not forever
for (volatile int j = 0; (j < 5000) && ((LPSPI_GetStatusFlags(self->spi_inst) & kLPSPI_ModuleBusyFlag) != 0); j++) {}
// Reconfigure the TCR, required after switch between DMA vs. non-DMA
LPSPI_Enable(self->spi_inst, false); // Disable first before new settings are applied
self->spi_inst->TCR = LPSPI_TCR_CPOL(self->master_config->cpol) | LPSPI_TCR_CPHA(self->master_config->cpha) |
@ -330,7 +336,9 @@ STATIC void machine_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint8
masterXfer.dataSize = len;
masterXfer.configFlags = (self->master_config->whichPcs << LPSPI_MASTER_PCS_SHIFT) | kLPSPI_MasterPcsContinuous | kLPSPI_MasterByteSwap;
LPSPI_MasterTransferBlocking(self->spi_inst, &masterXfer);
if (LPSPI_MasterTransferBlocking(self->spi_inst, &masterXfer) != kStatus_Success) {
mp_raise_OSError(EIO);
}
}
}