From c9370e6facea3484f5abf2c137f822f0a404baaf Mon Sep 17 00:00:00 2001
From: Romuald Conty <romuald@libnfc.org>
Date: Fri, 9 Apr 2010 23:11:20 +0000
Subject: [PATCH] Prevent from running polling on hardware that does not
 support it.

---
 examples/nfc-poll.c | 4 ++++
 libnfc/nfc.c        | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/examples/nfc-poll.c b/examples/nfc-poll.c
index 29542b4..3dbb59b 100644
--- a/examples/nfc-poll.c
+++ b/examples/nfc-poll.c
@@ -111,6 +111,10 @@ int main(int argc, const char* argv[])
     nfc_target_t antTargets[2];
     size_t szTargetFound;
 
+    if(pnd->nc == NC_PN531) {
+      // PN531 doesn't support hardware polling (InAutoPoll)
+      continue;
+    }
     printf("PN53x will poll during %ld ms\n", btPollNr * szTargetTypes * btPeriod * 150);
     bool res = nfc_initiator_poll_targets(pnd, &nttMifare, 1, btPollNr, btPeriod, antTargets, &szTargetFound);
     if( res ) {
diff --git a/libnfc/nfc.c b/libnfc/nfc.c
index efa68fe..3bd7e2f 100644
--- a/libnfc/nfc.c
+++ b/libnfc/nfc.c
@@ -587,6 +587,10 @@ nfc_initiator_poll_targets(const nfc_device_t* pnd,
 			   const byte_t btPollNr, const byte_t btPeriod, 
 			   nfc_target_t* pntTargets, size_t* pszTargetFound)
 {
+  if(pnd->nc == NC_PN531) {
+    // errno = ENOSUPP
+    return false;
+  }
 //   byte_t abtInAutoPoll[] = { 0xd4, 0x60, 0x0f, 0x01, 0x00 };
   size_t szTxInAutoPoll = 4 + szTargetTypes;
   byte_t *pbtTxInAutoPoll = malloc( szTxInAutoPoll );