It was obviously an April joke: iErrorCode which was renamed iPICCError is
indeed a PCD Error, so I renamed it to iLastError since communications errors are
also to handle at the device driver level (read chip level), although I guess
that some errors would be common to distinct devices.
PICC error are irrelevant because they can either be transmission error
detection (in which case the libnfc should retry the transmission) or
application-level errors the libnfc cannot be aware of.
- Rename the nfc_device_t's struct iErrorCode member to iPICCError (We are
likely to have both PICC and PCD errors fields to avoid unneeded complexity
at some point);
- Make the PN53x error descriptions static;
- Enhance some comments here and there.
Avoid redundant code in PN53x usb and uart drivers. Since it makes sense to
report errors at the nfc_device_t level, pass it directly to
pn53x_transceive().
Programs using the libnfc MAY use pn53x_transceive() to communicate with a NFC
device, and SHALL not use anymore pnd->pdc->transceive(). Code in the library
itself SHOULD avoid calling pnd->pdc->transceive(), so such construct have been
updated accordingly.
- New API functions: nfc_strerror(), nfc_strerror_r() and nfc_perror();
- Drivers now have a reference to chips callback methods;
- Rename -pn53x_err2string to pn53x_strerror and add it to pn53x_callbacks_list.
