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author | Jonathan Corbet <corbet@lwn.net> | 2019-07-22 22:42:10 +0300 |
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committer | Jonathan Corbet <corbet@lwn.net> | 2019-07-22 22:42:10 +0300 |
commit | e27a24210aa17b8a0cd462865130fe73afd7e001 (patch) | |
tree | b2d7b8311d280244fad3166792e8f447081a8bc9 /Documentation/driver-api/nfc/nfc-pn544.rst | |
parent | 224d5fd43d250f850d64fb6d668114aff29d7022 (diff) | |
parent | 5f9e832c137075045d15cd6899ab0505cfb2ca4b (diff) | |
download | linux-e27a24210aa17b8a0cd462865130fe73afd7e001.tar.xz |
Merge tag 'v5.3-rc1' into docs-next
Pull in all of the massive docs changes from elsewhere.
Diffstat (limited to 'Documentation/driver-api/nfc/nfc-pn544.rst')
-rw-r--r-- | Documentation/driver-api/nfc/nfc-pn544.rst | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/Documentation/driver-api/nfc/nfc-pn544.rst b/Documentation/driver-api/nfc/nfc-pn544.rst new file mode 100644 index 000000000000..6b2d8aae0c4e --- /dev/null +++ b/Documentation/driver-api/nfc/nfc-pn544.rst @@ -0,0 +1,34 @@ +============================================================================ +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 |