efm32trace.cpp

#include "em_gpio.h"
#include "trace/arm.hpp"
#include "trace/efm.hpp"

namespace trace::efm
{
    void SetupClock()
    {
        CMU_OscillatorEnable(cmuOsc_HFXO, true, true);
        CMU_ClockSelectSet(cmuClock_HF, cmuSelect_HFXO);

        CMU_ClockSelectSet(cmuClock_LFA, cmuSelect_HFCLK);
        CMU_ClockSelectSet(cmuClock_LFB, cmuSelect_HFCLKLE);
        CMU_ClockSelectSet(cmuClock_DBG, cmuSelect_HFCLK);

        /* EFM32 specific configuration to enable the TRACESWO IO pin */
        CMU_AUXHFRCOBandSet(cmuAUXHFRCOBand_14MHz);
        CMU_OscillatorEnable(cmuOsc_AUXHFRCO, true, true);

        SystemCoreClockUpdate();

        CMU_ClockEnable(cmuClock_HFPER, true);
        CMU_ClockEnable(cmuClock_DBG, true);
        CMU_ClockEnable(cmuClock_GPIO, true);
        CMU_ClockEnable(cmuClock_DBG, true);
    }

    void SetupGPIOForParallelTrace()
    {
        // NOTE: Track clock is enabled right after setting GPIO_ROUTE_TCLKPEN

        auto route = GPIO->ROUTE;
        route &= ~_GPIO_ROUTE_ETMLOCATION_MASK;
        route |= GPIO_ROUTE_ETMLOCATION_LOC0;

        route |= GPIO_ROUTE_TCLKPEN;
        route |= GPIO_ROUTE_TD0PEN;
        route |= GPIO_ROUTE_TD1PEN;
        route |= GPIO_ROUTE_TD2PEN;
        route |= GPIO_ROUTE_TD3PEN;

        GPIO->ROUTE = route;
        // ETM location 0:
        // CLK - PD7
        // D0  - PD6
        // D1  - PD3
        // D2  - PD4
        // D3  - PD5

        GPIO_PinModeSet(gpioPortD, 3, gpioModePushPull, 0);
        GPIO_PinModeSet(gpioPortD, 4, gpioModePushPull, 0);
        GPIO_PinModeSet(gpioPortD, 5, gpioModePushPull, 0);
        GPIO_PinModeSet(gpioPortD, 6, gpioModePushPull, 0);
        GPIO_PinModeSet(gpioPortD, 7, gpioModePushPull, 0);
    }
}

int main()
{
  trace::efm::SetupClock();
  trace::efm::SetupGPIOForParallelTrace();

  TpiuOptions tpiu = {
      .Protocol = TpiuProtocolParallel,
      .FormattingEnabled = true,
      .TracePortWidth = 4,
  };
  ITMOptions itm = {
      .TraceBusID = 1,
      .GlobalTimestampFrequency = ITMGlobalTimestampFrequencyDisabled,
      .LocalTimestampPrescaler = ITMLocalTimestampPrescalerNoPrescaling,
      .EnableLocalTimestamp = true,
      .ForwardDWT = false,
      .EnableSyncPacket = false,
      .EnabledStimulusPorts = ITM_ENABLE_STIMULUS_PORTS_ALL,
  };

  TpiuSetup(&tpiu);
  ITMSetup(&itm);
}