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Code Issues Wiki Activity

Support dual gyros sharing a common SPI bus

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This commit is contained in:
Steve Evans 2021-10-03 01:14:58 +01:00
parent a1c6cda572
commit 7ef7795944
10 changed files with 114 additions and 45 deletions
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65
src/main/drivers/bus_spi.c
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@ -137,7 +137,7 @@ bool spiInit(SPIDevice device)
// Return true if DMA engine is busy
bool spiIsBusy(const extDevice_t *dev)
{
return (dev->bus->curSegment != (busSegment_t *)NULL);
return (dev->bus->curSegment != (busSegment_t *)BUS_SPI_FREE);
}
// Indicate that the bus on which this device resides may initiate DMA transfers from interrupt context
@ -156,15 +156,15 @@ void spiWaitClaim(const extDevice_t *dev)
if (dev->bus->useAtomicWait) {
// Prevent race condition where the bus appears free, but a gyro interrupt starts a transfer
do {
ATOMIC_BLOCK(NVIC_PRIO_MPU_INT_EXTI) {
if (dev->bus->curSegment == (busSegment_t *)NULL) {
dev->bus->curSegment = (busSegment_t *)0x04;
ATOMIC_BLOCK(NVIC_PRIO_MAX) {
if (dev->bus->curSegment == (busSegment_t *)BUS_SPI_FREE) {
dev->bus->curSegment = (busSegment_t *)BUS_SPI_LOCKED;
}
}
} while (dev->bus->curSegment != (busSegment_t *)0x04);
} while (dev->bus->curSegment != (busSegment_t *)BUS_SPI_LOCKED);
} else {
// Wait for completion
while (dev->bus->curSegment != (busSegment_t *)NULL);
while (dev->bus->curSegment != (busSegment_t *)BUS_SPI_FREE);
}
}
@ -172,7 +172,7 @@ void spiWaitClaim(const extDevice_t *dev)
void spiWait(const extDevice_t *dev)
{
// Wait for completion
while (dev->bus->curSegment != (busSegment_t *)NULL);
while (dev->bus->curSegment != (busSegment_t *)BUS_SPI_FREE);
}
// Wait for bus to become free, then read/write block of data
@ -407,6 +407,7 @@ static void spiRxIrqHandler(dmaChannelDescriptor_t* descriptor)
}
busDevice_t *bus = dev->bus;
busSegment_t *nextSegment;
if (bus->curSegment->negateCS) {
// Negate Chip Select
@ -451,12 +452,23 @@ static void spiRxIrqHandler(dmaChannelDescriptor_t* descriptor)
}
// Advance through the segment list
bus->curSegment++;
nextSegment = bus->curSegment + 1;
if (bus->curSegment->len == 0) {
// The end of the segment list has been reached, so mark transactions as complete
bus->curSegment = (busSegment_t *)NULL;
if (nextSegment->len == 0) {
// If a following transaction has been linked, start it
if (nextSegment->txData) {
const extDevice_t *nextDev = (const extDevice_t *)nextSegment->txData;
busSegment_t *nextSegments = (busSegment_t *)nextSegment->rxData;
nextSegment->txData = NULL;
// The end of the segment list has been reached
spiSequenceStart(nextDev, nextSegments);
} else {
// The end of the segment list has been reached, so mark transactions as complete
bus->curSegment = (busSegment_t *)NULL;
}
} else {
bus->curSegment = nextSegment;
// After the completion of the first segment setup the init structure for the subsequent segment
if (bus->initSegment) {
spiInternalInitStream(dev, false);
@ -479,6 +491,7 @@ bool spiSetBusInstance(extDevice_t *dev, uint32_t device)
}
dev->bus = &spiBusDevice[SPI_CFG_TO_DEV(device)];
dev->useDMA = true;
if (dev->bus->busType == BUS_TYPE_SPI) {
// This bus has already been initialised
@ -495,7 +508,6 @@ bool spiSetBusInstance(extDevice_t *dev, uint32_t device)
}
bus->busType = BUS_TYPE_SPI;
dev->useDMA = true;
bus->useDMA = false;
bus->useAtomicWait = false;
bus->deviceCount = 1;
@ -637,4 +649,33 @@ uint8_t spiGetExtDeviceCount(const extDevice_t *dev)
{
return dev->bus->deviceCount;
}
// DMA transfer setup and start
void spiSequence(const extDevice_t *dev, busSegment_t *segments)
{
busDevice_t *bus = dev->bus;
ATOMIC_BLOCK(NVIC_PRIO_MAX) {
if ((bus->curSegment != (busSegment_t *)BUS_SPI_LOCKED) && spiIsBusy(dev)) {
/* Defer this transfer to be triggered upon completion of the current transfer. Blocking calls
* and those from non-interrupt context will have already called spiWaitClaim() so this will
* only happen for non-blocking calls called from an ISR.
*/
busSegment_t *endSegment = bus->curSegment;
if (endSegment) {
// Find the last segment of the current transfer
for (; endSegment->len; endSegment++);
// Record the dev and segments parameters in the terminating segment entry
endSegment->txData = (uint8_t *)dev;
endSegment->rxData = (uint8_t *)segments;
return;
}
}
}
spiSequenceStart(dev, segments);
}
#endif