I tried to change "lp0" in this->{DATA}{DEVICE} to "/dev/usb/lp0", but nothing changed...

As I said, that value is only ever being used in an error message. The purpose behind setting it was just to silence the warning...

I think that my usb adapter is not so compatible with Linux or maybe it's not a really usb to parallel port adapter...

Either that, or it isn't mapped to the I/O address 0x378 (which is hardcoded in Device::ParallelPort::drv::linux::linux_opendev() ).  The code in question is:

    ...
    base = 0x378;
    if (ioperm(base, LPSIZE, 1) < 0) {
            fprintf(stderr, "%s: ioperm:%s ", devname, strerror(errno)
+);
            RETVAL = -1;
    } else {
            RETVAL = base;
    }
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ioperm(2) can only fail with

    EINVAL Invalid address(-range).
    EPERM  The calling process has insufficient privilege.
    ENOMEM Out of memory.
    EIO    This call is not supported (on PowerPC).
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In particular, no checks are being made that the address actually maps to the intended hardware device.

You might want to check your dmesg output — mine, for example, says:

[   61.718702] parport_pc 00:0b: reported by Plug and Play ACPI
[   61.718797] parport0: PC-style at 0x378, irq 7 [PCSPP,TRISTATE]
[   63.870838] lp0: using parport0 (interrupt-driven).
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