Add API for setting the default/maximum transmit power. (#394)

include/openthread.h

@@ -441,6 +441,22 @@ const uint8_t *otGetMasterKey(uint8_t *aKeyLength);
  */
 ThreadError otSetMasterKey(const uint8_t *aKey, uint8_t aKeyLength);
 
+/**
+ * This function returns the maximum transmit power setting in dBm.
+ *
+ * @returns  The maximum transmit power setting.
+ *
+ */
+int8_t otGetMaxTransmitPower(void);
+
+/**
+ * This function sets the maximum transmit power in dBm.
+ *
+ * @param[in]  aPower  The maximum transmit power in dBm.
+ *
+ */
+void otSetMaxTransmitPower(int8_t aPower);
+
 /**
  * This function returns a pointer to the Mesh Local EID.
  *

src/core/mac/mac.cpp

@@ -98,6 +98,7 @@ Mac::Mac(ThreadNetif &aThreadNetif):
     mReceiveHead = NULL;
     mReceiveTail = NULL;
     mChannel = OPENTHREAD_CONFIG_DEFAULT_CHANNEL;
+    mMaxTransmitPower = OPENTHREAD_CONFIG_DEFAULT_MAX_TRANSMIT_POWER;
     mPanId = kPanIdBroadcast;
     mShortAddress = kShortAddrInvalid;
 
@@ -238,6 +239,16 @@ ThreadError Mac::SetChannel(uint8_t aChannel)
     return kThreadError_None;
 }
 
+int8_t Mac::GetMaxTransmitPower(void) const
+{
+    return mMaxTransmitPower;
+}
+
+void Mac::SetMaxTransmitPower(int8_t aPower)
+{
+    mMaxTransmitPower = aPower;
+}
+
 const char *Mac::GetNetworkName(void) const
 {
     return mNetworkName.m8;
@@ -472,6 +483,8 @@ void Mac::HandleBeginTransmit(void)
         ExitNow();
     }
 
+    sendFrame.SetPower(mMaxTransmitPower);
+
     switch (mState)
     {
     case kStateActiveScan:
@@ -500,6 +513,11 @@ void Mac::HandleBeginTransmit(void)
     // Security Processing
     ProcessTransmitSecurity(sendFrame);
 
+    if (sendFrame.GetPower() > mMaxTransmitPower)
+    {
+        sendFrame.SetPower(mMaxTransmitPower);
+    }
+
     SuccessOrExit(error = otPlatRadioTransmit());
 
     if (sendFrame.GetAckRequest() && !(otPlatRadioGetCaps() & kRadioCapsAckTimeout))

src/core/mac/mac.hpp

@@ -302,6 +302,22 @@ public:
      */
     ThreadError SetChannel(uint8_t aChannel);
 
+    /**
+     * This method returns the maximum transmit power in dBm.
+     *
+     * @returns  The maximum transmit power in dBm.
+     *
+     */
+    int8_t GetMaxTransmitPower(void) const;
+
+    /**
+     * This method sets the maximum transmit power in dBm.
+     *
+     * @param[in]  aPower  The maximum transmit power in dBm.
+     *
+     */
+    void SetMaxTransmitPower(int8_t aPower);
+
     /**
      * This method returns the IEEE 802.15.4 Network Name.
      *
@@ -470,6 +486,7 @@ private:
     ShortAddress mShortAddress;
     PanId mPanId;
     uint8_t mChannel;
+    int8_t mMaxTransmitPower;
 
     otNetworkName mNetworkName;
     otExtendedPanId mExtendedPanId;

src/core/openthread-core-default-config.h

@@ -65,6 +65,16 @@
 #define OPENTHREAD_CONFIG_DEFAULT_CHANNEL                   11
 #endif  // OPENTHREAD_CONFIG_DEFAULT_CHANNEL
 
+/**
+ * @def OPENTHREAD_CONFIG_DEFAULT_MAX_TRANSMIT_POWER
+ *
+ * The default IEEE 802.15.4 maximum transmit power (dBm)
+ *
+ */
+#ifndef OPENTHREAD_CONFIG_DEFAULT_MAX_TRANSMIT_POWER
+#define OPENTHREAD_CONFIG_DEFAULT_MAX_TRANSMIT_POWER        0
+#endif  // OPENTHREAD_CONFIG_DEFAULT_MAX_TRANSMIT_POWER
+
 /**
  * @def OPENTHREAD_CONFIG_ATTACH_DATA_POLL_PERIOD
  *

src/core/openthread.cpp

@@ -210,6 +210,16 @@ ThreadError otSetMasterKey(const uint8_t *aKey, uint8_t aKeyLength)
     return sThreadNetif->GetKeyManager().SetMasterKey(aKey, aKeyLength);
 }
 
+int8_t otGetMaxTransmitPower(void)
+{
+    return sThreadNetif->GetMac().GetMaxTransmitPower();
+}
+
+void otSetMaxTransmitPower(int8_t aPower)
+{
+    sThreadNetif->GetMac().SetMaxTransmitPower(aPower);
+}
+
 const otIp6Address *otGetMeshLocalEid(void)
 {
     return sThreadNetif->GetMle().GetMeshLocal64();