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pn53x_wrap_frame() and pn53x_unwrap_frame() functions return now frame length in bits on success and libnfc error code on failure.

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This commit is contained in:
Audrey Diacre 2012-01-04 14:59:16 +00:00
parent 0de1136037
commit 61c3e5b814
2 changed files with 30 additions and 23 deletions
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47
libnfc/chips/pn53x.c
View file

@ -223,28 +223,29 @@ pn53x_set_tx_bits (struct nfc_device *pnd, const uint8_t ui8Bits)
return NFC_SUCCESS; return NFC_SUCCESS;
} }
bool int
pn53x_wrap_frame (const uint8_t *pbtTx, const size_t szTxBits, const uint8_t *pbtTxPar, pn53x_wrap_frame (const uint8_t *pbtTx, const size_t szTxBits, const uint8_t *pbtTxPar,
uint8_t *pbtFrame, size_t *pszFrameBits) uint8_t *pbtFrame)
{ {
uint8_t btFrame; uint8_t btFrame;
uint8_t btData; uint8_t btData;
uint32_t uiBitPos; uint32_t uiBitPos;
uint32_t uiDataPos = 0; uint32_t uiDataPos = 0;
size_t szBitsLeft = szTxBits; size_t szBitsLeft = szTxBits;
size_t szFrameBits = 0;
// Make sure we should frame at least something // Make sure we should frame at least something
if (szBitsLeft == 0) if (szBitsLeft == 0)
return false; return NFC_ECHIP;
// Handle a short response (1byte) as a special case // Handle a short response (1byte) as a special case
if (szBitsLeft < 9) { if (szBitsLeft < 9) {
*pbtFrame = *pbtTx; *pbtFrame = *pbtTx;
*pszFrameBits = szTxBits; szFrameBits = szTxBits;
return true; return szFrameBits;
} }
// We start by calculating the frame length in bits // We start by calculating the frame length in bits
*pszFrameBits = szTxBits + (szTxBits / 8); szFrameBits = szTxBits + (szTxBits / 8);
// Parse the data bytes and add the parity bits // Parse the data bytes and add the parity bits
// This is really a sensitive process, mirror the frame bytes and append parity bits // This is really a sensitive process, mirror the frame bytes and append parity bits
@ -271,7 +272,7 @@ pn53x_wrap_frame (const uint8_t *pbtTx, const size_t szTxBits, const uint8_t *pb
uiDataPos++; uiDataPos++;
// Test if we are done // Test if we are done
if (szBitsLeft < 9) if (szBitsLeft < 9)
return true; return szFrameBits;
szBitsLeft -= 8; szBitsLeft -= 8;
} }
// Every 8 data bytes we lose one frame byte to the parities // Every 8 data bytes we lose one frame byte to the parities
@ -279,9 +280,8 @@ pn53x_wrap_frame (const uint8_t *pbtTx, const size_t szTxBits, const uint8_t *pb
} }
} }
bool int
pn53x_unwrap_frame (const uint8_t *pbtFrame, const size_t szFrameBits, uint8_t *pbtRx, size_t *pszRxBits, pn53x_unwrap_frame (const uint8_t *pbtFrame, const size_t szFrameBits, uint8_t *pbtRx, uint8_t *pbtRxPar)
uint8_t *pbtRxPar)
{ {
uint8_t btFrame; uint8_t btFrame;
uint8_t btData; uint8_t btData;
@ -289,19 +289,20 @@ pn53x_unwrap_frame (const uint8_t *pbtFrame, const size_t szFrameBits, uint8_t *
uint32_t uiDataPos = 0; uint32_t uiDataPos = 0;
uint8_t *pbtFramePos = (uint8_t *) pbtFrame; uint8_t *pbtFramePos = (uint8_t *) pbtFrame;
size_t szBitsLeft = szFrameBits; size_t szBitsLeft = szFrameBits;
size_t szRxBits = 0;
// Make sure we should frame at least something // Make sure we should frame at least something
if (szBitsLeft == 0) if (szBitsLeft == 0)
return false; return NFC_ECHIP;
// Handle a short response (1byte) as a special case // Handle a short response (1byte) as a special case
if (szBitsLeft < 9) { if (szBitsLeft < 9) {
*pbtRx = *pbtFrame; *pbtRx = *pbtFrame;
*pszRxBits = szFrameBits; szRxBits = szFrameBits;
return true; return szRxBits;
} }
// Calculate the data length in bits // Calculate the data length in bits
*pszRxBits = szFrameBits - (szFrameBits / 9); szRxBits = szFrameBits - (szFrameBits / 9);
// Parse the frame bytes, remove the parity bits and store them in the parity array // Parse the frame bytes, remove the parity bits and store them in the parity array
// This process is the reverse of WrapFrame(), look there for more info // This process is the reverse of WrapFrame(), look there for more info
@ -318,7 +319,7 @@ pn53x_unwrap_frame (const uint8_t *pbtFrame, const size_t szFrameBits, uint8_t *
uiDataPos++; uiDataPos++;
// Test if we are done // Test if we are done
if (szBitsLeft < 9) if (szBitsLeft < 9)
return true; return szRxBits;
szBitsLeft -= 9; szBitsLeft -= 9;
} }
// Every 8 data bytes we lose one frame byte to the parities // Every 8 data bytes we lose one frame byte to the parities
@ -1121,7 +1122,9 @@ pn53x_initiator_transceive_bits (struct nfc_device *pnd, const uint8_t *pbtTx, c
// Check if we should prepare the parity bits ourself // Check if we should prepare the parity bits ourself
if (!pnd->bPar) { if (!pnd->bPar) {
// Convert data with parity to a frame // Convert data with parity to a frame
pn53x_wrap_frame (pbtTx, szTxBits, pbtTxPar, abtCmd + 1, &szFrameBits); if ((res = pn53x_wrap_frame (pbtTx, szTxBits, pbtTxPar, abtCmd + 1)) < 0)
return res;
szFrameBits = res;
} else { } else {
szFrameBits = szTxBits; szFrameBits = szTxBits;
} }
@ -1160,7 +1163,9 @@ pn53x_initiator_transceive_bits (struct nfc_device *pnd, const uint8_t *pbtTx, c
// Check if we should recover the parity bits ourself // Check if we should recover the parity bits ourself
if (!pnd->bPar) { if (!pnd->bPar) {
// Unwrap the response frame // Unwrap the response frame
pn53x_unwrap_frame (abtRx + 1, szFrameBits, pbtRx, pszRxBits, pbtRxPar); if ((res = pn53x_unwrap_frame (abtRx + 1, szFrameBits, pbtRx, pbtRxPar)) < 0)
return res;
*pszRxBits = res;
} else { } else {
// Save the received bits // Save the received bits
*pszRxBits = szFrameBits; *pszRxBits = szFrameBits;
@ -1773,7 +1778,9 @@ pn53x_target_receive_bits (struct nfc_device *pnd, uint8_t *pbtRx, size_t *pszRx
// Check if we should recover the parity bits ourself // Check if we should recover the parity bits ourself
if (!pnd->bPar) { if (!pnd->bPar) {
// Unwrap the response frame // Unwrap the response frame
pn53x_unwrap_frame (abtRx + 1, szFrameBits, pbtRx, pszRxBits, pbtRxPar); if ((res = pn53x_unwrap_frame (abtRx + 1, szFrameBits, pbtRx, pbtRxPar)) < 0)
return res;
*pszRxBits = res;
} else { } else {
// Save the received bits // Save the received bits
*pszRxBits = szFrameBits; *pszRxBits = szFrameBits;
@ -1845,7 +1852,9 @@ pn53x_target_send_bits (struct nfc_device *pnd, const uint8_t *pbtTx, const size
// Check if we should prepare the parity bits ourself // Check if we should prepare the parity bits ourself
if (!pnd->bPar) { if (!pnd->bPar) {
// Convert data with parity to a frame // Convert data with parity to a frame
pn53x_wrap_frame (pbtTx, szTxBits, pbtTxPar, abtCmd + 1, &szFrameBits); if ((res = pn53x_wrap_frame (pbtTx, szTxBits, pbtTxPar, abtCmd + 1)) < 0)
return res;
szFrameBits = res;
} else { } else {
szFrameBits = szTxBits; szFrameBits = szTxBits;
} }

6
libnfc/chips/pn53x.h
View file

@ -268,10 +268,8 @@ int pn53x_transceive (struct nfc_device *pnd, const uint8_t *pbtTx, const siz
int pn53x_set_parameters (struct nfc_device *pnd, const uint8_t ui8Value, const bool bEnable); int pn53x_set_parameters (struct nfc_device *pnd, const uint8_t ui8Value, const bool bEnable);
int pn53x_set_tx_bits (struct nfc_device *pnd, const uint8_t ui8Bits); int pn53x_set_tx_bits (struct nfc_device *pnd, const uint8_t ui8Bits);
bool pn53x_wrap_frame (const uint8_t *pbtTx, const size_t szTxBits, const uint8_t *pbtTxPar, uint8_t *pbtFrame, int pn53x_wrap_frame (const uint8_t *pbtTx, const size_t szTxBits, const uint8_t *pbtTxPar, uint8_t *pbtFrame);
size_t *pszFrameBits); int pn53x_unwrap_frame (const uint8_t *pbtFrame, const size_t szFrameBits, uint8_t *pbtRx, uint8_t *pbtRxPar);
bool pn53x_unwrap_frame (const uint8_t *pbtFrame, const size_t szFrameBits, uint8_t *pbtRx, size_t *pszRxBits,
uint8_t *pbtRxPar);
bool pn53x_decode_target_data (const uint8_t *pbtRawData, size_t szRawData, bool pn53x_decode_target_data (const uint8_t *pbtRawData, size_t szRawData,
pn53x_type chip_type, nfc_modulation_type nmt, pn53x_type chip_type, nfc_modulation_type nmt,
nfc_target_info *pnti); nfc_target_info *pnti);