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Implement extended frame send/receive for PN532_UART driver.

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This commit is contained in:
Romuald Conty 2011-04-13 16:39:58 +00:00
parent 8a77b68b10
commit fe49ccd701
3 changed files with 52 additions and 8 deletions
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41
libnfc/chips/pn53x.c
View file

@ -358,8 +358,14 @@ pn53x_unwrap_frame (const byte_t * pbtFrame, const size_t szFrameBits, byte_t *
}
}
void
pn53x_build_frame(byte_t * pbtFrame, size_t * pszFrame, const byte_t * pbtData, const size_t szData)
/**
* @brief Build a PN53x frame
*
* @param pbtData payload (bytes array) of the frame, will become PD0, ..., PDn in PN53x frame
* @note The first byte of pbtData is the Command Code (CC)
*/
bool
pn53x_build_frame (byte_t * pbtFrame, size_t * pszFrame, const byte_t * pbtData, const size_t szData)
{
if (szData <= PN53x_NORMAL_FRAME__DATA_MAX_LEN) {
// LEN - Packet length = data length (len) + checksum (1) + end of stream marker (1)
@ -382,10 +388,37 @@ pn53x_build_frame(byte_t * pbtFrame, size_t * pszFrame, const byte_t * pbtData,
pbtFrame[szData + 7] = 0x00;
(*pszFrame) = szData + PN53x_NORMAL_FRAME__OVERHEAD;
} else if (szData <= PN53x_EXTENDED_FRAME__DATA_MAX_LEN) {
// Extended frame marker
pbtFrame[3] = 0xff;
pbtFrame[4] = 0xff;
// LENm
pbtFrame[5] = (szData + 1) >> 8;
// LENl
pbtFrame[6] = (szData + 1) & 0xff;
// LCS
pbtFrame[7] = 256 - ((pbtFrame[5] + pbtFrame[6]) & 0xff);
// TFI
pbtFrame[8] = 0xD4;
// DATA - Copy the PN53X command into the packet buffer
memcpy (pbtFrame + 9, pbtData, szData);
// DCS - Calculate data payload checksum
byte_t btDCS = (256 - 0xD4);
for (size_t szPos = 0; szPos < szData; szPos++) {
btDCS -= pbtData[szPos];
}
pbtFrame[9 + szData] = btDCS;
// 0x00 - End of stream marker
pbtFrame[szData + 10] = 0x00;
(*pszFrame) = szData + PN53x_EXTENDED_FRAME__OVERHEAD;
} else {
// FIXME: Build extended frame
abort();
ERR ("We can't send more than %d bytes in a raw (requested: %zd)", PN53x_EXTENDED_FRAME__DATA_MAX_LEN, szData);
return false;
}
return true;
}
bool

2
libnfc/chips/pn53x.h
View file

@ -329,6 +329,6 @@ bool pn53x_TgInitAsTarget (nfc_device_t * pnd, pn53x_target_mode_t ptm,
// Misc
bool pn53x_check_ack_frame (nfc_device_t * pnd, const byte_t * pbtRxFrame, const size_t szRxFrameLen);
bool pn53x_check_error_frame (nfc_device_t * pnd, const byte_t * pbtRxFrame, const size_t szRxFrameLen);
void pn53x_build_frame(byte_t * pbtFrame, size_t * pszFrame, const byte_t * pbtData, const size_t szData);
bool pn53x_build_frame (byte_t * pbtFrame, size_t * pszFrame, const byte_t * pbtData, const size_t szData);
#endif // __NFC_CHIPS_PN53X_H__