Clarify parameter name in phy_csma_params_t (ARMmbed#1773)

Rename symbol_backoff_time to backoff_time.

Author: Arto Kinnunen

nanostack/platform/arm_hal_phy.h

@@ -120,7 +120,7 @@ typedef struct phy_signal_info_s {
 
 /** CSMA-CA parameters */
 typedef struct phy_csma_params {
-    uint32_t symbol_backoff_time;    /**< CSMA Backoff symbol time before start CCA & TX. 0 should disable current backoff*/
+    uint32_t backoff_time;           /**< CSMA Backoff us time before start CCA & TX. 0 should disable current backoff*/
     bool cca_enabled;                /**< True will affect CCA check false start TX direct after backoff */
 } phy_csma_params_t;
 

source/MAC/IEEE802_15_4/mac_mcps_sap.c

@@ -1730,7 +1730,7 @@ int8_t mcps_generic_ack_build(protocol_interface_rf_mac_setup_s *rf_ptr, const m
     }
     //Disable TX Time
     phy_csma_params_t csma_params;
-    csma_params.symbol_backoff_time = 0;
+    csma_params.backoff_time = 0;
     csma_params.cca_enabled = false;
     rf_ptr->dev_driver->phy_driver->extension(PHY_EXTENSION_SET_CSMA_PARAMETERS, (uint8_t*) &csma_params);
     if (rf_ptr->active_pd_data_request) {

source/MAC/IEEE802_15_4/mac_pd_sap.c

@@ -190,7 +190,7 @@ void mac_pd_sap_set_phy_tx_time(protocol_interface_rf_mac_setup_s *rf_mac_setup,
         tx_time++;
     }
     phy_csma_params_t csma_params;
-    csma_params.symbol_backoff_time = tx_time;
+    csma_params.backoff_time = tx_time;
     csma_params.cca_enabled = cca_enabled;
     rf_mac_setup->dev_driver->phy_driver->extension(PHY_EXTENSION_SET_CSMA_PARAMETERS, (uint8_t*) &csma_params);
 }