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));
>
> 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.
>
--
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 [email protected].
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.
