| ============================================================================ |
| 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 |
