PIO Interrupts PCIe

Hello,

me again.

I made a new Design with PCIe + PIO. This time i configured the PIO as Bidirectional (tristate) ports. I tried to write the direction register in the PIO regiser map but when i read back i always read zeros and the IO are still Inputs. It seems i can't access the registers, only the data register works. I'm clueless.

Here my codesnippets from the driver: arg = 0xf;

unsigned long adr;
            adr = (unsigned long) device->baseAdress; // Base adress of PCI MEMRegion
            adr += (unsigned long)device->startAdress; // Start Adress PIO
            adr += (unsigned long)4; // second 32Bit Register
            
            printk(KERN_DEBUG "Schreibe %8lx an %8lx \n", arg, adr);
            iowrite32(arg,(void*)(adr));
            wmb();
            ret = ioread32((void*)(adr));
            printk(KERN_DEBUG "PIO_DIR AFTER : %8lx \n", ret);

and here the output:

--- Quote Start ---

[ 4062.810750] Schreibe 7 an f88c4044

[ 4062.810757] PIO_DIR AFTER : 0

--- Quote End ---

any idea?

Thanks for reading.