Function spi_event

core/spi.c:92–125

}

static void spi_event(enum sched_item_id id) {
    uint8_t bitCount = spi.transferBits < spi.deviceBits ? spi.transferBits : spi.deviceBits;
    spi.rxFrame <<= bitCount;
    /* Handle loopback */
    if (unlikely(spi.cr0 >> 7 & 1)) {
        spi.rxFrame |= spi.txFrame >> (32 - bitCount);
    }
    /* For now, allow only receives from coprocessor */
    else if (spi.arm) {
        spi.rxFrame |= spi.deviceFrame >> (32 - bitCount);
    }
    spi.deviceFrame <<= bitCount;
    spi.deviceFrame |= spi.txFrame >> (32 - bitCount);
    spi.txFrame <<= bitCount;

    spi.deviceBits -= bitCount;
    if (spi.deviceBits == 0) {
        uint32_t rxData = 0;
        spi.deviceBits = spi.device_transfer(spi.deviceFrame, &rxData);
        spi.deviceFrame = rxData << (32 - spi.deviceBits);
    }

    spi.transferBits -= bitCount;
    if (spi.transferBits == 0 && unlikely(spi.cr2 >> 7 & 1)) {
        /* Note: rfve bound check was performed when starting the transfer */
        spi.rxFifo[(spi.rfvi + spi.rfve++) & (SPI_RXFIFO_DEPTH - 1)] = spi.rxFrame;
        spi_update_thresholds();
    }

    uint32_t ticks = spi_next_transfer();
    if (ticks) {
        sched_repeat(id, ticks);
    }
}

static void spi_update(void) {
    spi_update_thresholds();