New function nfc_initiator_target_is_present() to test is a previously selected target is in the field.

NEWS

@@ -12,6 +12,8 @@ API Changes:
       information
     - No more in/out function parameter: nfc_initiator_transceive_bytes() now
       take a constant size for Rx buffer
+    - New nfc_initiator_target_is_present() to test is the previously selected
+      target is available in the field
 
 New in 1.6.0-rc1:
 

include/nfc/nfc.h

@@ -86,6 +86,7 @@ extern  "C" {
   NFC_EXPORT int nfc_initiator_transceive_bits (nfc_device *pnd, const uint8_t *pbtTx, const size_t szTxBits, const uint8_t *pbtTxPar, uint8_t *pbtRx, uint8_t *pbtRxPar);
   NFC_EXPORT int nfc_initiator_transceive_bytes_timed (nfc_device *pnd, const uint8_t *pbtTx, const size_t szTx, uint8_t *pbtRx, uint32_t *cycles);
   NFC_EXPORT int nfc_initiator_transceive_bits_timed (nfc_device *pnd, const uint8_t *pbtTx, const size_t szTxBits, const uint8_t *pbtTxPar, uint8_t *pbtRx, uint8_t *pbtRxPar, uint32_t *cycles);
+  NFC_EXPORT int nfc_initiator_target_is_present (nfc_device *pnd, const nfc_target nt);
 
 /* NFC target: act as tag (i.e. MIFARE Classic) or NFC target device. */
   NFC_EXPORT int nfc_target_init (nfc_device *pnd, nfc_target *pnt, uint8_t *pbtRx, const size_t szRx, int timeout);

libnfc/chips/pn53x.c

@@ -199,6 +199,13 @@ pn53x_transceive (struct nfc_device *pnd, const uint8_t *pbtTx, const size_t szT
       if (pbtRx[0] & 0x40) { abort(); } // MI detected
       CHIP_DATA(pnd)->last_status_byte = pbtRx[0] & 0x3f;
       break;
+    case Diagnose:
+      if (pbtTx[1] == 0x06) { // Diagnose: Card presence detection
+        CHIP_DATA(pnd)->last_status_byte = pbtRx[0] & 0x3f;
+      } else {
+        CHIP_DATA(pnd)->last_status_byte = 0;
+      };
+      break;
     case InDeselect:
     case InRelease:
       if (CHIP_DATA(pnd)->type == RCS360) {
@@ -1624,6 +1631,22 @@ pn53x_initiator_deselect_target (struct nfc_device *pnd)
   return pn53x_InDeselect (pnd, 0);   // 0 mean deselect all selected targets
 }
 
+int 
+pn53x_initiator_target_is_present (struct nfc_device *pnd, const nfc_target nt)
+{
+  // TODO Check if nt is equal to current target
+  const uint8_t abtCmd[] = { Diagnose, 0x06 };
+  uint8_t abtRx[1];
+  int res = 0;
+
+  if ((res = pn53x_transceive (pnd, abtCmd, sizeof (abtCmd), abtRx, sizeof (abtRx), -1)) < 0)
+    return res;
+  if (res==1) {
+    return NFC_SUCCESS;
+  }
+  return NFC_ETGRELEASED;
+}
+
 #define SAK_ISO14443_4_COMPLIANT 0x20
 #define SAK_ISO18092_COMPLIANT   0x40
 int

libnfc/chips/pn53x.h

@@ -334,6 +334,7 @@ int    pn53x_initiator_transceive_bits_timed (struct nfc_device *pnd, const uint
 int    pn53x_initiator_transceive_bytes_timed (struct nfc_device *pnd, const uint8_t *pbtTx, const size_t szTx,
                                           uint8_t *pbtRx, uint32_t *cycles);
 int    pn53x_initiator_deselect_target (struct nfc_device *pnd);
+int    pn53x_initiator_target_is_present (struct nfc_device *pnd, const nfc_target nt);
 
 // NFC device as Target functions
 int    pn53x_target_init (struct nfc_device *pnd, nfc_target *pnt, uint8_t *pbtRx, const size_t szRxLen, int timeout);

libnfc/drivers/acr122_pcsc.c

@@ -502,6 +502,7 @@ const struct nfc_driver acr122_pcsc_driver = {
   .initiator_transceive_bits        = pn53x_initiator_transceive_bits,
   .initiator_transceive_bytes_timed = pn53x_initiator_transceive_bytes_timed,
   .initiator_transceive_bits_timed  = pn53x_initiator_transceive_bits_timed,
+  .initiator_target_is_present      = pn53x_initiator_target_is_present,
 
   .target_init           = pn53x_target_init,
   .target_send_bytes     = pn53x_target_send_bytes,

libnfc/drivers/acr122_usb.c

@@ -759,6 +759,7 @@ const struct nfc_driver acr122_usb_driver = {
   .initiator_transceive_bits        = pn53x_initiator_transceive_bits,
   .initiator_transceive_bytes_timed = pn53x_initiator_transceive_bytes_timed,
   .initiator_transceive_bits_timed  = pn53x_initiator_transceive_bits_timed,
+  .initiator_target_is_present      = pn53x_initiator_target_is_present,
 
   .target_init           = pn53x_target_init,
   .target_send_bytes     = pn53x_target_send_bytes,

libnfc/drivers/acr122s.c

@@ -737,6 +737,7 @@ const struct nfc_driver acr122s_driver = {
   .initiator_transceive_bits        = pn53x_initiator_transceive_bits,
   .initiator_transceive_bytes_timed = pn53x_initiator_transceive_bytes_timed,
   .initiator_transceive_bits_timed  = pn53x_initiator_transceive_bits_timed,
+  .initiator_target_is_present      = pn53x_initiator_target_is_present,
 
   .target_init           = pn53x_target_init,
   .target_send_bytes     = pn53x_target_send_bytes,

libnfc/drivers/arygon.c

@@ -579,6 +579,7 @@ const struct nfc_driver arygon_driver = {
   .initiator_transceive_bits        = pn53x_initiator_transceive_bits,
   .initiator_transceive_bytes_timed = pn53x_initiator_transceive_bytes_timed,
   .initiator_transceive_bits_timed  = pn53x_initiator_transceive_bits_timed,
+  .initiator_target_is_present      = pn53x_initiator_target_is_present,
 
   .target_init           = pn53x_target_init,
   .target_send_bytes     = pn53x_target_send_bytes,

libnfc/drivers/pn532_uart.c

@@ -521,6 +521,7 @@ const struct nfc_driver pn532_uart_driver = {
   .initiator_transceive_bits        = pn53x_initiator_transceive_bits,
   .initiator_transceive_bytes_timed = pn53x_initiator_transceive_bytes_timed,
   .initiator_transceive_bits_timed  = pn53x_initiator_transceive_bits_timed,
+  .initiator_target_is_present      = pn53x_initiator_target_is_present,
 
   .target_init           = pn53x_target_init,
   .target_send_bytes     = pn53x_target_send_bytes,

libnfc/drivers/pn53x_usb.c

@@ -772,6 +772,7 @@ const struct nfc_driver pn53x_usb_driver = {
   .initiator_transceive_bits        = pn53x_initiator_transceive_bits,
   .initiator_transceive_bytes_timed = pn53x_initiator_transceive_bytes_timed,
   .initiator_transceive_bits_timed  = pn53x_initiator_transceive_bits_timed,
+  .initiator_target_is_present      = pn53x_initiator_target_is_present,
 
   .target_init           = pn53x_target_init,
   .target_send_bytes     = pn53x_target_send_bytes,

libnfc/nfc-internal.h

@@ -149,6 +149,7 @@ struct nfc_driver {
   int (*initiator_transceive_bits) (struct nfc_device *pnd, const uint8_t * pbtTx, const size_t szTxBits, const uint8_t * pbtTxPar, uint8_t * pbtRx, uint8_t * pbtRxPar);
   int (*initiator_transceive_bytes_timed) (struct nfc_device *pnd, const uint8_t * pbtTx, const size_t szTx, uint8_t * pbtRx, uint32_t * cycles);
   int (*initiator_transceive_bits_timed) (struct nfc_device *pnd, const uint8_t * pbtTx, const size_t szTxBits, const uint8_t * pbtTxPar, uint8_t * pbtRx, uint8_t * pbtRxPar, uint32_t * cycles);
+  int (*initiator_target_is_present) (struct nfc_device *pnd, const nfc_target nt);
 
   int (*target_init) (struct nfc_device *pnd, nfc_target * pnt, uint8_t * pbtRx, const size_t szRx, int timeout);
   int (*target_send_bytes) (struct nfc_device *pnd, const uint8_t * pbtTx, const size_t szTx, int timeout);

libnfc/nfc.c

@@ -687,7 +687,21 @@ nfc_initiator_transceive_bits (nfc_device *pnd, const uint8_t *pbtTx, const size
 int
 nfc_initiator_transceive_bytes_timed (nfc_device *pnd, const uint8_t *pbtTx, const size_t szTx, uint8_t *pbtRx, uint32_t *cycles)
 {
-  HAL (initiator_transceive_bytes_timed, pnd, pbtTx, szTx, pbtRx, cycles)
+  HAL (initiator_transceive_bytes_timed, pnd, pbtTx, szTx, pbtRx, cycles);
+}
+
+/** @ingroup initiator
+ * @brief Check target presence
+ * @return Returns 0 on success, otherwise returns libnfc's error code.
+ *
+ * This function tests if \a nfc_target is currently present on NFC device.
+ * @warning The target have to be selected before check its presence
+ * @warning To run the test, one or more commands will be sent to target
+*/
+int
+nfc_initiator_target_is_present (nfc_device *pnd, const nfc_target nt)
+{
+  HAL (initiator_target_is_present, pnd, nt);
 }
 
 /** @ingroup initiator