Method test_clock_freq

libraries/AP_HAL_ChibiOS/SPIDevice.cpp:511–560

test clock frequencies. This measures the actual SPI clock frequencies on all configured SPI buses. Used during board bringup to validate clock configuration */

  to validate clock configuration
 */
void SPIDevice::test_clock_freq(void)
{
    // delay for USB to come up
    DEV_PRINTF("Waiting for USB\n");
    for (uint8_t i=0; i<3; i++) {
        hal.scheduler->delay(1000);
        DEV_PRINTF("Waiting %u\n", (unsigned)AP_HAL::millis());
    }
    DEV_PRINTF("CLOCKS=\n");
    for (uint8_t i=0; i<ARRAY_SIZE(bus_clocks); i++) {
        DEV_PRINTF("%u:%u ", unsigned(i+1), unsigned(bus_clocks[i]));
    }
    DEV_PRINTF("\n");

    // we will send 1024 bytes without any CS asserted and measure the
    // time it takes to do the transfer
    uint16_t len = 1024;
    uint8_t *buf1 = (uint8_t *)hal.util->malloc_type(len, AP_HAL::Util::MEM_DMA_SAFE);
    uint8_t *buf2 = (uint8_t *)hal.util->malloc_type(len, AP_HAL::Util::MEM_DMA_SAFE);
    for (uint8_t i=0; i<ARRAY_SIZE(spi_devices); i++) {
        SPIConfig spicfg {};
        const uint32_t target_freq = 2000000UL;
        // use a clock divisor of 256 for maximum resolution
#if defined(STM32H7)
        spicfg.cfg1 = derive_freq_flag_bus(spi_devices[i].busid, target_freq);
#else
        spicfg.cr1 = derive_freq_flag_bus(spi_devices[i].busid, target_freq);
#endif
        spiAcquireBus(spi_devices[i].driver);
        spiStart(spi_devices[i].driver, &spicfg);
        uint32_t t0 = AP_HAL::micros();
        spiStartExchange(spi_devices[i].driver, len, buf1, buf2);
        chSysLock();
        msg_t msg = osalThreadSuspendTimeoutS(&spi_devices[i].driver->thread, chTimeMS2I(100));
        chSysUnlock();
        if (msg == MSG_TIMEOUT) {
            spiAbort(spi_devices[i].driver);
            DEV_PRINTF("SPI[%u] FAIL %p %p\n", spi_devices[i].busid, buf1, buf2);
            spiStop(spi_devices[i].driver);
            spiReleaseBus(spi_devices[i].driver);
            continue;
        }
        uint32_t t1 = AP_HAL::micros();
        spiStop(spi_devices[i].driver);
        spiReleaseBus(spi_devices[i].driver);
        DEV_PRINTF("SPI[%u] clock=%u\n", unsigned(spi_devices[i].busid), unsigned(1000000ULL * len * 8ULL / uint64_t(t1 - t0)));
    }
    hal.util->free_type(buf1, len, AP_HAL::Util::MEM_DMA_SAFE);
    hal.util->free_type(buf2, len, AP_HAL::Util::MEM_DMA_SAFE);
}
#endif // HAL_SPI_CHECK_CLOCK_FREQ

#endif // HAL_USE_SPI