1*e253d2c5SMauro Carvalho Chehab============================================================================ 2*e253d2c5SMauro Carvalho ChehabKernel driver for the NXP Semiconductors PN544 Near Field Communication chip 3*e253d2c5SMauro Carvalho Chehab============================================================================ 4*e253d2c5SMauro Carvalho Chehab 5*e253d2c5SMauro Carvalho Chehab 6*e253d2c5SMauro Carvalho ChehabGeneral 7*e253d2c5SMauro Carvalho Chehab------- 8*e253d2c5SMauro Carvalho Chehab 9*e253d2c5SMauro Carvalho ChehabThe PN544 is an integrated transmission module for contactless 10*e253d2c5SMauro Carvalho Chehabcommunication. The driver goes under drives/nfc/ and is compiled as a 11*e253d2c5SMauro Carvalho Chehabmodule named "pn544". 12*e253d2c5SMauro Carvalho Chehab 13*e253d2c5SMauro Carvalho ChehabHost Interfaces: I2C, SPI and HSU, this driver supports currently only I2C. 14*e253d2c5SMauro Carvalho Chehab 15*e253d2c5SMauro Carvalho ChehabProtocols 16*e253d2c5SMauro Carvalho Chehab--------- 17*e253d2c5SMauro Carvalho Chehab 18*e253d2c5SMauro Carvalho ChehabIn the normal (HCI) mode and in the firmware update mode read and 19*e253d2c5SMauro Carvalho Chehabwrite functions behave a bit differently because the message formats 20*e253d2c5SMauro Carvalho Chehabor the protocols are different. 21*e253d2c5SMauro Carvalho Chehab 22*e253d2c5SMauro Carvalho ChehabIn the normal (HCI) mode the protocol used is derived from the ETSI 23*e253d2c5SMauro Carvalho ChehabHCI specification. The firmware is updated using a specific protocol, 24*e253d2c5SMauro Carvalho Chehabwhich is different from HCI. 25*e253d2c5SMauro Carvalho Chehab 26*e253d2c5SMauro Carvalho ChehabHCI messages consist of an eight bit header and the message body. The 27*e253d2c5SMauro Carvalho Chehabheader contains the message length. Maximum size for an HCI message is 28*e253d2c5SMauro Carvalho Chehab33. In HCI mode sent messages are tested for a correct 29*e253d2c5SMauro Carvalho Chehabchecksum. Firmware update messages have the length in the second (MSB) 30*e253d2c5SMauro Carvalho Chehaband third (LSB) bytes of the message. The maximum FW message length is 31*e253d2c5SMauro Carvalho Chehab1024 bytes. 32*e253d2c5SMauro Carvalho Chehab 33*e253d2c5SMauro Carvalho ChehabFor the ETSI HCI specification see 34*e253d2c5SMauro Carvalho Chehabhttp://www.etsi.org/WebSite/Technologies/ProtocolSpecification.aspx 35