Rename ConnectionParams_t -> PreferredConnectionParams_t

For actual connections, full ConnectionParameters is used. But
as per BLE specification, Generic Access Service can display
preferred connection parameters which is a smaller subset and
ConnectionParams_t matches exactly. Thus we rename/repurpose
it to PreferredConnectionParams_t.

features/FEATURE_BLE/ble/gap/Gap.h

@@ -548,7 +548,7 @@ public:
     };
 
     /**
-     * Parameters of a BLE connection.
+     * Preferred connection parameter display in Generic Access Service.
      */
     typedef struct {
         /**
@@ -592,7 +592,7 @@ public:
          * @note maxConnectionInterval is in ms in the formulae above.
          */
         uint16_t connectionSupervisionTimeout;
-    } ConnectionParams_t;
+    } PreferredConnectionParams_t;
 
     /**
      * Assign the event handler implementation that will be used by the gap

features/FEATURE_BLE/ble/generic/GenericGap.h

@@ -75,7 +75,7 @@ class GenericGap :
     using Gap::default_central_privacy_configuration;
 
     typedef typename ble::whitelist_t whitelist_t;
-    typedef typename Gap::ConnectionParams_t ConnectionParams_t;
+    typedef typename Gap::PreferredConnectionParams_t PreferredConnectionParams_t;
 
     // Imports from Gap
 #if BLE_ROLE_BROADCASTER

features/FEATURE_BLE/ble/pal/GenericAccessService.h

@@ -57,7 +57,7 @@ struct GenericAccessService {
      * Parameters Characteristic
      */
      virtual ble_error_t get_peripheral_preferred_connection_parameters(
-         ::Gap::ConnectionParams_t& parameters
+         ::Gap::PreferredConnectionParams_t& parameters
     ) = 0;
 
     /**
@@ -74,7 +74,7 @@ struct GenericAccessService {
      * Parameters Characteristic
      */
     virtual ble_error_t set_peripheral_preferred_connection_parameters(
-        const ::Gap::ConnectionParams_t& parameters
+        const ::Gap::PreferredConnectionParams_t& parameters
    ) = 0;
 
 private:

features/FEATURE_BLE/source/generic/GenericGap.tpp

@@ -73,7 +73,7 @@ static bool is_in_range(T value, T lower_bound, T higher_bound)
  * timeout to be equal to 0xFFFF. When it is the case that value can be
  * interpreted as "non specific".
  */
-static bool is_preferred_connection_params_valid(const ::Gap::ConnectionParams_t *params)
+static bool is_preferred_connection_params_valid(const ::Gap::PreferredConnectionParams_t *params)
 {
     if (params == NULL) {
         return false;

features/FEATURE_BLE/targets/TARGET_CORDIO/CordioGattServer.h

@@ -142,12 +142,12 @@ public:
     /**
      * @see ::GattServer::getPreferredConnectionParams
      */
-    ::Gap::ConnectionParams_t getPreferredConnectionParams();
+    ::Gap::PreferredConnectionParams_t getPreferredConnectionParams();
 
     /**
      * @see ::GattServer::setPreferredConnectionParams
      */
-    void setPreferredConnectionParams(const ::Gap::ConnectionParams_t& params);
+    void setPreferredConnectionParams(const ::Gap::PreferredConnectionParams_t& params);
 
 #if 0 // Disabled until reworked and reintroduced to GattServer API
     /**

features/FEATURE_BLE/targets/TARGET_CORDIO/CordioPalGenericAccessService.h

@@ -87,7 +87,7 @@ public:
 #endif // Disabled until reworked and reintroduced to GattServer API
 
     virtual ble_error_t get_peripheral_preferred_connection_parameters(
-        ::Gap::ConnectionParams_t& parameters
+        ::Gap::PreferredConnectionParams_t& parameters
     ) {
 #if BLE_FEATURE_GATT_SERVER
         parameters = gatt_server().getPreferredConnectionParams();
@@ -98,7 +98,7 @@ public:
     }
 
     virtual ble_error_t set_peripheral_preferred_connection_parameters(
-        const ::Gap::ConnectionParams_t& parameters
+        const ::Gap::PreferredConnectionParams_t& parameters
     ) {
 #if BLE_FEATURE_GATT_SERVER
         gatt_server().setPreferredConnectionParams(parameters);

features/FEATURE_BLE/targets/TARGET_CORDIO/source/CordioGattServer.cpp

@@ -800,9 +800,9 @@ bool GattServer::isOnDataReadAvailable_() const
     return true;
 }
 
-::Gap::ConnectionParams_t GattServer::getPreferredConnectionParams()
+::Gap::PreferredConnectionParams_t GattServer::getPreferredConnectionParams()
 {
-    ::Gap::ConnectionParams_t params = { 0 };
+    ::Gap::PreferredConnectionParams_t params = { 0 };
     memcpy(&params.minConnectionInterval, generic_access_service.ppcp, 2);
     memcpy(&params.maxConnectionInterval, generic_access_service.ppcp + 2, 2);
     memcpy(&params.slaveLatency, generic_access_service.ppcp + 4, 2);
@@ -810,7 +810,7 @@ bool GattServer::isOnDataReadAvailable_() const
     return params;
 }
 
-void GattServer::setPreferredConnectionParams(const ::Gap::ConnectionParams_t& params)
+void GattServer::setPreferredConnectionParams(const ::Gap::PreferredConnectionParams_t& params)
 {
     memcpy(generic_access_service.ppcp, &params.minConnectionInterval, 2);
     memcpy(generic_access_service.ppcp + 2, &params.maxConnectionInterval, 2);