mirror of
https://github.com/torvalds/linux.git
synced 2024-11-14 16:12:02 +00:00
1353a10c47
The pn544 driver no longer has a /dev/pn544 interface nor a sysfs one. Reported-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
33 lines
1.1 KiB
Plaintext
33 lines
1.1 KiB
Plaintext
Kernel driver for the NXP Semiconductors PN544 Near Field
|
|
Communication chip
|
|
|
|
General
|
|
-------
|
|
|
|
The PN544 is an integrated transmission module for contactless
|
|
communication. The driver goes under drives/nfc/ and is compiled as a
|
|
module named "pn544".
|
|
|
|
Host Interfaces: I2C, SPI and HSU, this driver supports currently only I2C.
|
|
|
|
Protocols
|
|
---------
|
|
|
|
In the normal (HCI) mode and in the firmware update mode read and
|
|
write functions behave a bit differently because the message formats
|
|
or the protocols are different.
|
|
|
|
In the normal (HCI) mode the protocol used is derived from the ETSI
|
|
HCI specification. The firmware is updated using a specific protocol,
|
|
which is different from HCI.
|
|
|
|
HCI messages consist of an eight bit header and the message body. The
|
|
header contains the message length. Maximum size for an HCI message is
|
|
33. In HCI mode sent messages are tested for a correct
|
|
checksum. Firmware update messages have the length in the second (MSB)
|
|
and third (LSB) bytes of the message. The maximum FW message length is
|
|
1024 bytes.
|
|
|
|
For the ETSI HCI specification see
|
|
http://www.etsi.org/WebSite/Technologies/ProtocolSpecification.aspx
|