StarterWare SPI on BeagleBone Black / Debian

[Gregor Steiner]

Hi,

I want to use SPI through direct memory access on Debian, here is what I got so far:

int enableSPIClock()
{
    // map a pointer to the clock control block
    pClockControl = (char*)mmap(0, 4096, PROT_READ | PROT_WRITE, MAP_SHARED, memFd, SOC_CM_PER_REGS);

    HWREG(pClockControl + CM_PER_SPI1_CLKCTRL) |= CM_PER_SPI1_CLKCTRL_MODULEMODE_ENABLE;
    while(CM_PER_SPI1_CLKCTRL_MODULEMODE_ENABLE != (HWREG(pClockControl + CM_PER_SPI1_CLKCTRL) & CM_PER_SPI1_CLKCTRL_MODULEMODE));
   
    return 0;
}

int enableSPI()
{
    enableSPIClock();
   
    McSPIReset(spi);
    McSPICSEnable(spi);
    McSPIMasterModeEnable(spi);
   
    // set D0 as output-MOSI , set D1 as input-MISO
    McSPIMasterModeConfig(spi, MCSPI_MULTI_CH, MCSPI_TX_RX_MODE, MCSPI_CH0CONF_DPE0_ENABLED | MCSPI_CH0CONF_DPE1_DISABLED, chNum);
    McSPIClkConfig(spi, 48000000, 6000000, chNum, MCSPI_CLK_MODE_0);
    McSPIWordLengthSet(spi, MCSPI_WORD_LENGTH(8), chNum);
    McSPICSPolarityConfig(spi, MCSPI_CS_POL_LOW, chNum);
    McSPITxFIFOConfig(spi, MCSPI_TX_FIFO_ENABLE, chNum);
    McSPIRxFIFOConfig(spi, MCSPI_RX_FIFO_ENABLE, chNum);
   
    return 0;
}

int spiWrite(uint8_t *tx, uint32_t length)
{
    // cs line is forced to low state.
    McSPICSAssert(spi, chNum);

    // enable the spi channel for communication.
    McSPIChannelEnable(spi, chNum);

    while (length > 0)
    {
        McSPITransmitData(spi, (unsigned int)(*tx++), chNum);
        length--;
       
        unsigned int rx = McSPIReceiveData(spi, chNum);
    }

    // force cs line to the inactive state.
    McSPICSDeAssert(spi, chNum);

    // Disable the spi channel.
    McSPIChannelDisable(spi, chNum);    
}

I'm writing to a DAC and every 2nd or 3rd message actually goes through (gets recognized by the DAC).

The StarterWare site http://processors.wiki.ti.com/index.php/StarterWare_McSPI references the Interrupt and DMA mode, but I'm not sure if I should use them..?
If anyone has tried a similar thing I'd be more than happy to hear about it.

[cedric....@gmail.com]

Hello Gregor, 

I'm actually working on a project incolving a SPI connection between a BeagleBone black and an AD7606 (ADC). I have a couple of problems to enable properly the SPI connection, could you give me more details about how you have done it ? (if it worked).

I'm programming the BB_black in bare-metal, and it will communicate with the ADC using the SPI, so I really need to find out how to do it in order for my system to work.

Best regards,

Cedric.

[Mark Lazarewicz]

Bare Metal is not Debian?  If you use bare metal you need to set up all pin mux and initialize memory controller typically with a gel file in CCS.  Briefly looking at your code assuming nothing is interference with mux I'd make sure your SPI chipselect is properly timed with a scope if you're truly getting commands through.  Also a cheap Salae logic analyzer is very handy for what you're doing costs about  $200 

Sent from Yahoo Mail on Android

On Thu, May 12, 2016 at 9:12 AM, cedric....@gmail.com

<cedric....@gmail.com> wrote:

Hello Gregor, 

I'm actually working on a project incolving a SPI connection between a BeagleBone black and an AD7606 (ADC). I have a couple of problems to enable properly the SPI connection, could you give me more details about how you have done it ? (if it worked).

I'm programming the BB_black in bare-metal, and it will communicate with the ADC using the SPI, so I really need to find out how to do it in order for my system to work.

Best regards,

Cedric.

Le dimanche 31 août 2014 14:03:31 UTC+2, Gregor Steiner a écrit :

Hi,

I want to use SPI through direct memory access on Debian, here is what I got so far:

int enableSPIClock()
{
    // map a pointer to the clock control block
    pClockControl = (char*)mmap(0, 4096, PROT_READ | PROT_WRITE, MAP_SHARED, memFd, SOC_CM_PER_REGS);

    HWREG(pClockControl + CM_PER_SPI1_CLKCTRL) |= CM_PER_SPI1_CLKCTRL_ MODULEMODE_ENABLE;


    while(CM_PER_SPI1_CLKCTRL_ MODULEMODE_ENABLE != (HWREG(pClockControl + CM_PER_SPI1_CLKCTRL) & CM_PER_SPI1_CLKCTRL_MODULEMODE ));

The StarterWare site http://processors.wiki.ti.com/ index.php/StarterWare_McSPI references the Interrupt and DMA mode, but I'm not sure if I should use them..?

If anyone has tried a similar thing I'd be more than happy to hear about it.

--
For more options, visit http://beagleboard.org/discuss
---
You received this message because you are subscribed to the Google Groups "BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/b76f52ec-e5a5-49d9-b4cb-24cc56e3c03e%40googlegroups.com.

For more options, visit https://groups.google.com/d/optout.