add otPlatRadioGetCaps method to check radio capabilities (#53)

add doxygen for otRadioCaps

remove tmp file

examples/platform/posix/radio.cpp

@@ -260,6 +260,11 @@ int8_t otPlatRadioGetNoiseFloor()
     return 0;
 }
 
+otRadioCaps otPlatRadioGetCaps()
+{
+    return kRadioCapsNone;
+}
+
 ThreadError otPlatRadioHandleTransmitDone(bool *rxPending)
 {
     ThreadError error = kThreadError_None;

include/platform/radio.h

@@ -77,6 +77,17 @@ enum
     kPhyUsPerSymbol     = ((kPhyBitsPerOctet / kPhySymbolsPerOctet) * 1000000) / kPhyBitRate,
 };
 
+/**
+ *   This enum represents radio capabilities.
+ *
+ */
+
+typedef enum otRadioCaps
+{
+    kRadioCapsNone          = 0,  ///< None
+    kRadioCapsAckTimeout    = 1,  ///< Radio supports AckTime event
+} otRadioCaps;
+
 /**
  * This structure represents an IEEE 802.15.4 radio frame.
  */
@@ -272,6 +283,13 @@ ThreadError otPlatRadioHandleTransmitDone(bool *aFramePending);
  */
 int8_t otPlatRadioGetNoiseFloor(void);
 
+/**
+ * Get the radio capabilities.
+ *
+ * @returns The radio capability bit vector. The stack enables or disables some functions based on this value.
+ */
+otRadioCaps otPlatRadioGetCaps(void);
+
 /**
  * @}
  *

src/core/mac/mac.cpp

@@ -516,7 +516,7 @@ void Mac::HandleBeginTransmit(void)
 
     SuccessOrExit(error = otPlatRadioTransmit(&mSendFrame));
 
-    if (mSendFrame.GetAckRequest())
+    if (mSendFrame.GetAckRequest() && !(otPlatRadioGetCaps() & kRadioCapsAckTimeout))
     {
         mAckTimer.Start(kAckTimeout);
         otLogDebgMac("ack timer start\n");