Linux NFC subsystemSince 2011 the Linux kernel provides a NFC subsystem for some NFC devices. The same device can be used by the Linux NFC subsystem and also my CCID driver. We then have a conflict!
The kernel driver will use the device before the CCID driver has a chance to use it. Loading the CCID driver in pcsc-lite will then fail with an error message: "
Can't claim interface"
Devices supported by linux NFC driversAccording to drivers/nfc/pn533.c
The ACS ACR122U reader is also in the (unsupported) list of readers for my CCID driver.
So if you have such a reader and a "recent" Linux kernel (version 3.5 or more) you may not be able to use the CCID driver with this device.