From a785405b368050210b6de6c998b66da15ac1297d Mon Sep 17 00:00:00 2001
From: Nicolas Tsiftes <nvt@sics.se>
Date: Thu, 19 Feb 2015 11:26:43 +0100
Subject: [PATCH] Make it possible to set and get the CC2420's CCA threshold
 through the extended radio API.

---
 dev/cc2420/cc2420.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/dev/cc2420/cc2420.c b/dev/cc2420/cc2420.c
index 1e0ce8c75..970f9dca7 100644
--- a/dev/cc2420/cc2420.c
+++ b/dev/cc2420/cc2420.c
@@ -152,6 +152,7 @@ static int cc2420_send(const void *data, unsigned short len);
 
 static int cc2420_receiving_packet(void);
 static int pending_packet(void);
+static int get_cca_threshold(void);
 static int cc2420_cca(void);
 
 signed char cc2420_last_rssi;
@@ -186,6 +187,9 @@ get_value(radio_param_t param, radio_value_t *value)
       }
     }
     return RADIO_RESULT_OK;
+  case RADIO_PARAM_CCA_THRESHOLD:
+    *value = get_cca_threshold() + RSSI_OFFSET;
+    return RADIO_RESULT_OK;
   case RADIO_PARAM_RSSI:
     /* Return the RSSI value in dBm */
     *value = cc2420_rssi();
@@ -241,6 +245,9 @@ set_value(radio_param_t param, radio_value_t value)
     }
     cc2420_set_txpower(output_power[i - 1].config);
     return RADIO_RESULT_OK;
+  case RADIO_PARAM_CCA_THRESHOLD:
+    cc2420_set_cca_threshold(value - RSSI_OFFSET);
+    return RADIO_RESULT_OK;
   default:
     return RADIO_RESULT_NOT_SUPPORTED;
   }
@@ -1033,6 +1040,17 @@ pending_packet(void)
   return CC2420_FIFOP_IS_1;
 }
 /*---------------------------------------------------------------------------*/
+static int
+get_cca_threshold(void)
+{
+  int value;
+
+  GET_LOCK();
+  value = (int8_t)(getreg(CC2420_RSSI) >> 8);
+  RELEASE_LOCK();
+  return value;
+}
+/*---------------------------------------------------------------------------*/
 void
 cc2420_set_cca_threshold(int value)
 {