Major PHY layer modifications

The PHY layer had a lot of duplicated code in various geographic regions.
In this commit we have tried to concentrate all common functionaliy into
one single class which LoRaPHY that provides three kind of methods:

i) Non virtual base methods which are there for upper layer use, e.g.,
   providing access to driver or generic PHY layer functionality which
   needs to be exposed to upper layers.

ii) Virtual methods (no hard limit on implementation) that can be overriden
    in derived classes. Some PHY implementations will need that as they may
    come with very peculiar channel schemes, e.g., dynamic channel schemes
    in US bands.

iii) Protected methods which are only available for the derived PHYs

We have adopted a mechanism for the dervied PHYs to announce their differenmtiating
parameters in their constructors by filling up a data structure known as lora_phy_params_t
which exists at base level. Access modifier for this data structure is protected so it can only be
used by the base or derived classes, i.e., no exposure to upper layers.

For extra functionality and differentiating controls, a derived PHY can override any virual method as necessary.

In addition to that we have adopted the Mbed-OS style guide and have changed data structures and code to reflect that.
Some data structures are removed.

* Algorithm to get alternate DR is modified. Current scheme, works as multiples of 6 as EU and EU like PHYs
provide 6 datarates. We make sure that we try a datarate at least once. If nuber of join retries is a multiple
of 6, we may try multiple times on each data rate.

* Most of the PHYs with dynamic channel plans, always override the above mentioned algorithm as the rules governing
  this algorithm do not hild in their case.

* band_t data structure is enhanced with lower band frequency and higher band frequency. That enables us to validate
  frequency based upon the band and hence we can have a single function for all PHYs to validate frequency.

* In some PHYs, there were some extra channel masks were defined which were not being used. Hence removed.

* EIRP table corrected in some PHYs based upon spec.

* PHY functions in response to Mac commands are renamed to reflect what they exactly do.
  for example accept_rx_param_setup_req() because that's what they do. they can either accept
  the mac command or reject it.# Please enter the commit message for your changes.

Author: Hasnain Virk

features/lorawan/LoRaWANStack.cpp

@@ -224,9 +224,9 @@ lorawan_status_t LoRaWANStack::send_compliance_test_frame_to_mac()
 {
     loramac_mcps_req_t mcps_req;
 
-    GetPhyParams_t phy_params;
-    PhyParam_t default_datarate;
-    phy_params.Attribute = PHY_DEF_TX_DR;
+    get_phy_params_t phy_params;
+    phy_param_t default_datarate;
+    phy_params.attribute = PHY_DEF_TX_DR;
     default_datarate = _lora_phy.get_phy_params(&phy_params);
 
     prepare_special_tx_frame(_compliance_test.app_port);
@@ -236,7 +236,7 @@ lorawan_status_t LoRaWANStack::send_compliance_test_frame_to_mac()
         mcps_req.req.unconfirmed.fport = _compliance_test.app_port;
         mcps_req.f_buffer = _tx_msg.f_buffer;
         mcps_req.f_buffer_size = _tx_msg.f_buffer_size;
-        mcps_req.req.unconfirmed.data_rate = default_datarate.Value;
+        mcps_req.req.unconfirmed.data_rate = default_datarate.value;
 
         tr_info("Transmit unconfirmed compliance test frame %d bytes.", mcps_req.f_buffer_size);
 
@@ -249,7 +249,7 @@ lorawan_status_t LoRaWANStack::send_compliance_test_frame_to_mac()
         mcps_req.f_buffer = _tx_msg.f_buffer;
         mcps_req.f_buffer_size = _tx_msg.f_buffer_size;
         mcps_req.req.confirmed.nb_trials = _num_retry;
-        mcps_req.req.confirmed.data_rate = default_datarate.Value;
+        mcps_req.req.confirmed.data_rate = default_datarate.value;
 
         tr_info("Transmit confirmed compliance test frame %d bytes.", mcps_req.f_buffer_size);
 
@@ -286,9 +286,9 @@ lorawan_status_t LoRaWANStack::send_frame_to_mac()
     lorawan_status_t status;
     loramac_mib_req_confirm_t mib_get_params;
 
-    GetPhyParams_t phy_params;
-    PhyParam_t default_datarate;
-    phy_params.Attribute = PHY_DEF_TX_DR;
+    get_phy_params_t phy_params;
+    phy_param_t default_datarate;
+    phy_params.attribute = PHY_DEF_TX_DR;
     default_datarate = _lora_phy.get_phy_params(&phy_params);
 
     mcps_req.type = _tx_msg.type;
@@ -302,7 +302,7 @@ lorawan_status_t LoRaWANStack::send_frame_to_mac()
         mib_get_params.type = MIB_CHANNELS_DATARATE;
         if(mib_get_request(&mib_get_params) != LORAWAN_STATUS_OK) {
             tr_debug("Couldn't get MIB parameters: Using default data rate");
-            mcps_req.req.unconfirmed.data_rate = default_datarate.Value;
+            mcps_req.req.unconfirmed.data_rate = default_datarate.value;
         } else {
             mcps_req.req.unconfirmed.data_rate = mib_get_params.param.channel_data_rate;
         }
@@ -316,7 +316,7 @@ lorawan_status_t LoRaWANStack::send_frame_to_mac()
         mib_get_params.type = MIB_CHANNELS_DATARATE;
         if(mib_get_request(&mib_get_params) != LORAWAN_STATUS_OK) {
             tr_debug("Couldn't get MIB parameters: Using default data rate");
-            mcps_req.req.confirmed.data_rate = default_datarate.Value;
+            mcps_req.req.confirmed.data_rate = default_datarate.value;
         } else {
             mcps_req.req.confirmed.data_rate = mib_get_params.param.channel_data_rate;
         }
@@ -328,7 +328,7 @@ lorawan_status_t LoRaWANStack::send_frame_to_mac()
         mib_get_params.type = MIB_CHANNELS_DATARATE;
         if(mib_get_request(&mib_get_params) != LORAWAN_STATUS_OK) {
             tr_debug("Couldn't get MIB parameters: Using default data rate");
-            mcps_req.req.proprietary.data_rate = default_datarate.Value;
+            mcps_req.req.proprietary.data_rate = default_datarate.value;
         } else {
             mcps_req.req.proprietary.data_rate = mib_get_params.param.channel_data_rate;
         }
@@ -977,32 +977,21 @@ void LoRaWANStack::mcps_indication_handler(loramac_mcps_indication_t *mcps_indic
             break;
         default:
             if (is_port_valid(mcps_indication->port) == true ||
-                    mcps_indication->type == MCPS_PROPRIETARY) {
+                mcps_indication->type == MCPS_PROPRIETARY) {
 
                 // Valid message arrived.
-                // Save message to buffer with session information.
-                if (_rx_msg.msg.mcps_indication.buffer_size > LORAMAC_PHY_MAXPAYLOAD) {
-                    // This may never happen as both radio and MAC are limited
-                    // to the size 255 bytes
-                    tr_debug("Cannot receive more than buffer capacity!");
-                    if (_callbacks.events) {
-                        const int ret = _queue->call(_callbacks.events, RX_ERROR);
-                        MBED_ASSERT(ret != 0);
-                        (void)ret;
-                    }
-                    return;
-                } else {
-                    _rx_msg.type = LORAMAC_RX_MCPS_INDICATION;
-                    _rx_msg.msg.mcps_indication.buffer_size = mcps_indication->buffer_size;
-                    _rx_msg.msg.mcps_indication.port = mcps_indication->port;
-
-                    // no copy, just set the pointer for the user
-                    _rx_msg.msg.mcps_indication.buffer = mcps_indication->buffer;
-                }
+                _rx_msg.type = LORAMAC_RX_MCPS_INDICATION;
+                _rx_msg.msg.mcps_indication.buffer_size = mcps_indication->buffer_size;
+                _rx_msg.msg.mcps_indication.port = mcps_indication->port;
+
+                // no copy, just set the pointer for the user
+                _rx_msg.msg.mcps_indication.buffer =
+                mcps_indication->buffer;
 
                 // Notify application about received frame..
                 tr_debug("Received %d bytes", _rx_msg.msg.mcps_indication.buffer_size);
                 _rx_msg.receive_ready = true;
+
                 if (_callbacks.events) {
                     const int ret = _queue->call(_callbacks.events, RX_DONE);
                     MBED_ASSERT(ret != 0);