// TODO: not yet thread safe
void spiTransaction(spiClient_t *client, volatile void *rxBuf, void *txBuf, uint16_t size) {
spiStruct_t *interface = &spiData[client->interface];
uint8_t head = interface->head;
spiSlot_t *slot = &interface->slots[head];
slot->size = size;
slot->rxBuf = (uint32_t)rxBuf;
slot->txBuf = (uint32_t)txBuf;
slot->client = client;
interface->head = (head + 1) % SPI_SLOTS;
spiTriggerSchedule(client->interface);
}
static void spiEndTxn(spiStruct_t *interface) {
uint8_t tail = interface->tail;
spiClient_t *client = interface->slots[tail].client;
uint32_t tmp;
spiDisableSPI(interface);
spiDisableDMA(interface);
spiDeselect(client);
// record longest txn
tmp = timerMicros() - interface->txnStart;
if (tmp > interface->txnMaxTime)
interface->txnMaxTime = tmp;
spiNotify(client);
tail = (tail + 1) % SPI_SLOTS;
interface->tail = tail;
interface->txRunning = 0;
spiTriggerSchedule(client->interface);
}
