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TI-8148-EVM board, does it need to initialize using PCIE?

Wally Yeh
Prodigy 20 points

Hi, recently I test my TI-8148-EVM board, and follow the "TI81XX PSP PCI Express Root Complex Driver User Guide" to enable PCIE.

I change some DIP switch and modified kernel config by guide, and I can use PCIE

But I wondering can I use GPIO pin to control PCIE enable/disable, so I link GPIO15 to PCIE enable, and write a bash script to set this pin high after I get into system.

And I find PCIE is unable to use now, I think maybe this pin should be pulled high before kernel do PCIE init functions. but I search the arch/arm/mach-omap2/board-ti8148evm.c, and can't find any function like this. could someone tell me where should I set this pin high in kernel code?

thanks.

  • 0
    TI__Guru**** 170625 points

    Hello,

    Have a look on the below wiki page:

    http://processors.wiki.ti.com/index.php/TI81XX_PSP_GPIO_Driver_User_Guide#Kernel_Level

    Make pin 30 as output and set the value as high. 

    gpio_direction_output(30, 1);

    Best Regards,
    Pavel
  • 0 in reply to Pavel Botev
    Prodigy 20 points

    Hi, Pavel:

        Thanks for reply.

        This gpio_direction_output( ) function really work, I add it in arch/arm/mach-omap2/board-ti8148evm.c.

        So PCI-E does needs initialize(although I still don't know when kernel did this ), It's still not working if I type "echo 30 > /sys/class/gpio/export" and set 1 to gpio value after I get into Linux root filesystem.

  • 0 in reply to Wally Yeh
    TI__Guru**** 170625 points

    Hi Wally,

    It seems to me that the PCIe is initialized in the ti-ezsdk_dm814x-evm_5_05_01_04/board-support/linux-2.6.37-psp04.04.00.01/arch/arm/mach-omap2/pcie-ti81xx.c file, see functions :

    ti81xx_pcie_probe()

    ti81xx_pcie_setup()

    __init ti81xx_pcie_rc_init(void)

    BR,

    Pavel