Keystone II - Linux interface to FFT Coprocessor

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Is it possible to access the FFT coprocessor and the Antenna Interface (AIF2) from ARM cores running Linux, without the need of interacting with DSPs?

Well, for the start  that sounds good.

Maybe I should tell you our problems running FFTC on ARM and you could provide some information how to deal with it correctly.

At first there is no Linux library for FFTC available in mcsdk_linux_3_00_04_18/  and an ARM build is not supported in  pdk_keystone2_3_00_04_18/ .

I've compiled one for ARM by adapting the QMSS build for FFTC.

When using the FFTC example from C66x for ARM (see code beneath), I get a segmentation fault occurs when calling fftc_init().

/* Initialize FFTC driver */
    Fftc_GlobalCfg      		fftcGlobalCfg;
    Fftc_DeviceCfg              fftcDevCfg;

    Fftc_RetVal             retVal;

    int txQueueIx;
    int coreNum = 0;


    /* Set up the FFTC Configuration Register */
    for (txQueueIx = 0; txQueueIx < FFTC_MAX_NUM_TXQUEUES; txQueueIx ++)
    {
        fftcGlobalCfg.queueFlowidOverwrite [txQueueIx]   =   0;
        fftcGlobalCfg.queuePriority [txQueueIx]          =   0;
    }
    fftcGlobalCfg.starvationPeriodVal            =   0x0;
    fftcGlobalCfg.bDisableFFT                    =   0;

    /* Initialize FFTC driver for instance number specified. */
     fftcDevCfg.cpdmaNum     =   Cppi_CpDma_FFTC_A_CPDMA;
     fftcDevCfg.baseQueueNum =   QMSS_FFTC_A_QUEUE_BASE;
     fftcDevCfg.cfgRegs      =   (void *) (CSL_FFTC_0_CFG_REGS);
     retVal = Fftc_init (fftcInstNum, &fftcGlobalCfg, &fftcDevCfg);
     if (retVal == FFTC_RETVAL_SUCCESS)
     {
         System_printf ("[Core %d]: FFTC instance %d successfully initialized \n", coreNum, fftcInstNum);
     }
     else
     {
         System_printf ("[Core %d]: FFTC init failed on instance %d \n", coreNum, fftcInstNum);
         return -1;
     }

TI doesn't provide any examples for FFTC on ARM.

What exactly do I have to do to get it to work?

Kind regards,

Tobias Jaeuthe

Ok I understand thank you,

but one last question:

When I program the FFTC from ARM via CSL Layer do I still need a Linux driver for FFTC?

Because there does not exist a driver for FFTC yet.

Regards,

Tobias Jaeuthe