From 4128b23f86cad6168153dd59db6763bae3c1a0d6 Mon Sep 17 00:00:00 2001
From: Romuald Conty <romuald@libnfc.org>
Date: Fri, 9 Apr 2010 16:18:42 +0000
Subject: [PATCH] Add new function pn53x_decode_target_data() that fill
 nfc_target_info_t with TargetData byte stream.

---
 libnfc/chips/pn53x.c | 36 ++++++++++++++++++++++++++++++++++++
 libnfc/chips/pn53x.h |  1 +
 2 files changed, 37 insertions(+)

diff --git a/libnfc/chips/pn53x.c b/libnfc/chips/pn53x.c
index d5767cb..d59fbba 100644
--- a/libnfc/chips/pn53x.c
+++ b/libnfc/chips/pn53x.c
@@ -238,3 +238,39 @@ bool pn53x_unwrap_frame(const byte_t* pbtFrame, const size_t szFrameBits, byte_t
   }
 }
 
+bool 
+pn53x_decode_target_data(const byte_t* pbtRawData, size_t szDataLen, nfc_chip_t nc, nfc_target_type_t ntt, nfc_target_info_t* pnti)
+{
+  switch(ntt) {
+    case NTT_MIFARE:
+    case NTT_GENERIC_PASSIVE_106:
+      // We skip target number (Tg)
+      pbtRawData++;
+      // Somehow they switched the lower and upper ATQA bytes around for the PN531 chipset
+      if (nc == NC_PN531) {
+	pnti->nai.abtAtqa[1] = *(pbtRawData++);
+	pnti->nai.abtAtqa[0] = *(pbtRawData++);
+      } else {
+	pnti->nai.abtAtqa[0] = *(pbtRawData++);
+	pnti->nai.abtAtqa[1] = *(pbtRawData++);
+      }
+      pnti->nai.btSak = *(pbtRawData++);
+      // Copy the NFCID1
+      pnti->nai.szUidLen = *(pbtRawData++);
+      memcpy(pnti->nai.abtUid, pbtRawData, pnti->nai.szUidLen);
+      pbtRawData += pnti->nai.szUidLen;
+      
+      // Did we received an optional ATS (Smardcard ATR)
+      if (szDataLen > (pnti->nai.szUidLen + 5)) {
+	pnti->nai.szAtsLen = *(pbtRawData++);
+	memcpy(pnti->nai.abtAts, pbtRawData, pnti->nai.szAtsLen);
+      } else {
+	pnti->nai.szAtsLen = 0;
+      }
+      break;
+    default:
+      return false;
+      break;
+  }
+  return true;
+}
diff --git a/libnfc/chips/pn53x.h b/libnfc/chips/pn53x.h
index fc64d9e..a703a16 100644
--- a/libnfc/chips/pn53x.h
+++ b/libnfc/chips/pn53x.h
@@ -76,6 +76,7 @@ bool pn53x_set_parameters(const nfc_device_t* pnd, uint8_t ui8Value);
 bool pn53x_set_tx_bits(const nfc_device_t* pnd, uint8_t ui8Bits);
 bool pn53x_wrap_frame(const byte_t* pbtTx, const size_t szTxBits, const byte_t* pbtTxPar, byte_t* pbtFrame, size_t* pszFrameBits);
 bool pn53x_unwrap_frame(const byte_t* pbtFrame, const size_t szFrameBits, byte_t* pbtRx, size_t* pszRxBits, byte_t* pbtRxPar);
+bool pn53x_decode_target_data(const byte_t* pbtRawData, size_t szDataLen, nfc_chip_t nc, nfc_target_type_t ntt, nfc_target_info_t* pnti);
 
 #endif // __NFC_CHIPS_PN53X_H__