NFC

Near-field communication devices have become pretty easy to operate and read out under Linux. This page explains how to quickly set up the most common NFC scanners.

Install ccid , libnfc , acsccid , pcsclite and pcsc-tools .

The pcsclite package ships a pcscd.socket which will cause the pcscd server to start when a program requests it. Alternatively, you can manually start/enable the pcscd.service.

After installing libnfc , it is important that you re-plug your card reader as it ships with a few udev rules and kernel module blacklist that need to load before loading the actual driver.

Now everything should already be in place for a test scan. Plug in your NFC reader and run pcsc_scan. This tool will try to communicate with your scanner and also poll for any NFC cards placed on your scanner. If you try to scan a card after the tool has found your scanner, you should see events printed on your terminal.

$ pcsc_scan

Using reader plug'n play mechanism
Scanning present readers...
0: ACS ACR122U 00 00
 
Sun Sep 5 05:15:10 2021
 Reader 0: ACS ACR122U 00 00
 Event number: 0
 Card state: Card removed,

See https://ccid.apdu.fr/#readers for a list of scanners supported by ccid and https://nfc-tools.github.io/resources/ by libnfc.

In case things do not seem to work, investigate the log of pcscd.service

Some laptops (notably ASUS ROG models with a Keystone slot) have a built-in NXP NFC controller connected via I2C. The kernel driver nxp-nci_i2c may load successfully and RF polling appears active in dmesg, but no tags are ever discovered.

This is caused by three bugs in the upstream nci and nxp-nci kernel modules affecting NCI 2.0 protocol handling. As of kernel 6.18, these are not yet fixed upstream.

Check if you are affected:

$ dmesg | grep -i nxp-nci
$ cat /sys/class/nfc/nfc*/name

If RF polling starts but RF_INTF_ACTIVATED_NTF never appears, see linux-nxp-nfc-fix for patched DKMS modules.

Known ACPI IDs: NXP1001, NXP1002, NXP3001, NXP7471.

• Hardware