HWI_enter/HWI_exit macro build error OMAPL138

Hi Barry,

HWI_enter and HWI_exit are assembly macros.  As such, they must be used in assembly language context.

Steve

Hi Steve

Thanks for the prompt reply.

My latter post was somewhat hurried as I was trying to avoid the forum maintenance time-out.

We did realise the problem was due to the assembly nature of the macro. What we haven't seen is an example of how this assembly macro can be incorporated and used with the PSP in a typical scenario (being used in C context).

Are there any examples of these important macro's being used in a such a way?

Many Thanks

Barry

Hi Barry,

Is there a reason you're not using the HWI dispatcher?  If you use the dispatcher, then you don't need to worry about these _enter/_exit macros.

But, if you don't want to use the dispatcher, then to use the HWI_enter/_exit macros you'll need to write a little bit of assembly code.

One way to do this would be to write an assembly interrupt service routine that's mapped to your HWI so that it runs when the interrupt fires.  Call HWI_enter.  Then SEM_post (you may need to call a C function from within your assembly ISR).  Then call HWI_exit.

Steve

Hi Steve

We do use the dispatcher for our project and our FPGA  interrupt (hence don't use HWI_enter/HWI_exit).

The problem arises because our SPI/EDMA implementation uses the platform support package (PSP). We use GIO_submit()  (see User Guide - OMAPL138 BIOS PSP User Guide 01.30.01). This is  pre-built package and when the EDMA competes the asynchronous transfer a pre-defined call-back function is called as follows

 --------------PSEUDO initialisation code - Left out PIN MUX and GPIO interrupt configuration   -------------------------------

GIO_Handle  spiHandle  = NULL;

GIO_AppCallback  spi_dma_callback1;

GIO_Attrs           gioAttrs            = GIO_ATTRS;
Spi_ChanParams      chanParams;

chanParams.hEdma = hEdma[0];

spiHandle =  GIO_create("/Spi1",IOM_INOUT,NULL,&chanParams,&gioAttrs);

spi_dma_callback1.fxn = spi_dma_callback1_fn;  
spi_dma_callback1.arg = &loopRead1[0];

    memset(&dataparam1,0x00, sizeof(Spi_DataParam));
    dataparam1.chipSelect   = SPI1_SCS1;        
    dataparam1.bufLen       = sizeof(loopWrite);
    dataparam1.flags        = FALSE;                    
    dataparam1.dataFormat   = Spi_DataFormat_0;   
    dataparam1.outBuffer    = NULL;
    dataparam1.inBuffer     = (Uint8*)loopRead1;

--------------------------------------------------------------------------------------------------------------------------

----------------------------------- Our FPGA Interrupt routine - written using dispatcher --------------

void fpgaInputIsr(Ptr gp0_0_Interrupt)

{

    Int      status = IOM_COMPLETED;

    gpioIntStatus = gpioRegs->BANK[GPIO_BANK_0].INTSTAT; 

    if (gpioIntStatus & CSL_GPIO_INTSTAT_STAT10_MASK)

        Bank0Isr10 +=1;

   else

        UnknownIsr +=1;

    Gpio_clearInterruptStatus(gpio0,&pinCmdArg);     

    status = GIO_submit(spiHandle, IOM_READ, &dataparam1, &(dataparam1.bufLen), &spi_dma_callback1);  

    if( !((IOM_COMPLETED != status) || (IOM_PENDING != status)) )

    {

        gioSubtErr++;
        while(1);

   }

    return;

}

----------------------------------------------------------------------------------------------------------------------------------

------------------------------------------ Asynchronous Callback function used by PSP ------------------------

void spi_dma_callback1_fn(Ptr arg, Int status, Ptr buf, size_t size)
{
 
    if(IOM_COMPLETED == status || -13 == status) {     
        SWI_post(&testSWI);                                                    --------- OUR PROBLEM - how to SWI_post() here correctly
    }else {
        spiDmaFail1++;
}

----------------------------------------------------------------------------------------------------------------------------------

I am not sure how how to implement an assembly wrapper in this context as we do not have access to the dispatcher of the PSP. We have checked by placing a HWI_isHWI() call within spi_dma_callback1_fn() and it shows we are in the hardware context. 

BUT - if the PSP is not using the dispatcher and we are in a hardware context should the callback function not have an INTERRUPT keyword in this case ?

I also need to clarify how the PSP operating here. Our FPGA interrupt (h/w context) executes GIO_submit(). Is this the correct operation for the PSP

1 : SPI/EDMA transfer initiated

2 : We return from our FPGA hardware interrupt

3 : The DMA controller and EDMA operate in the background giving TSKs etc time to execute.

4: The callback function is executed and we return to hardware context.

This is an asynchronous callback -  I am assuming when we execute the callback function we have not remained in the interrupt context the entire time. (ie from GIO_submit() to callback function).

Clarification on these points would greatly help ..

Many Thanks

Barry