Implemented the NETOPT_CCA_THRESHOLD option for AT86RF231

drivers/at86rf2xx/at86rf2xx_getset.c

@@ -17,6 +17,7 @@
  * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
  * @author      Baptiste Clenet <bapclenet@gmail.com>
  * @author      Daniel Krebs <github@daniel-krebs.net>
+ * @author      Kévin Roussel <Kevin.Roussel@inria.fr>
  *
  * @}
  */
@@ -310,6 +311,31 @@ void at86rf2xx_set_csma_seed(at86rf2xx_t *dev, uint8_t entropy[2])
     at86rf2xx_reg_write(dev, AT86RF2XX_REG__CSMA_SEED_1, tmp);
 }
 
+int8_t at86rf2xx_get_cca_threshold(at86rf2xx_t *dev)
+{
+    int8_t tmp = at86rf2xx_reg_read(dev, AT86RF2XX_REG__CCA_THRES);
+    tmp &= AT86RF2XX_CCA_THRES_MASK__CCA_ED_THRES;
+    tmp <<= 1;
+    return (RSSI_BASE_VAL + tmp);
+}
+
+void at86rf2xx_set_cca_threshold(at86rf2xx_t *dev, int8_t value)
+{
+    /* ensure the given value is negative, since a CCA threshold > 0 is
+       just impossible: thus, any positive value given is considered
+       to be the absolute value of the actually wanted threshold */
+    if (value > 0) {
+        value = -value;
+    }
+    /* transform the dBm value in the form
+       that will fit in the AT86RF2XX_REG__CCA_THRES register */
+    value -= RSSI_BASE_VAL;
+    value >>= 1;
+    value &= AT86RF2XX_CCA_THRES_MASK__CCA_ED_THRES;
+    value |= AT86RF2XX_CCA_THRES_MASK__RSVD_HI_NIBBLE;
+    at86rf2xx_reg_write(dev, AT86RF2XX_REG__CCA_THRES, value);
+}
+
 void at86rf2xx_set_option(at86rf2xx_t *dev, uint16_t option, bool state)
 {
     uint8_t tmp;

drivers/at86rf2xx/at86rf2xx_netdev.c

@@ -15,6 +15,7 @@
  *
  * @author      Thomas Eichinger <thomas.eichinger@fu-berlin.de>
  * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
+ * @author      Kévin Roussel <Kevin.Roussel@inria.fr>
  *
  * @}
  */
@@ -569,6 +570,15 @@ static int _get(gnrc_netdev_t *device, netopt_t opt, void *val, size_t max_len)
             }
             break;
 
+        case NETOPT_CCA_THRESHOLD:
+            if (max_len < sizeof(int8_t)) {
+                res = -EOVERFLOW;
+            } else {
+                *((int8_t *)val) = at86rf2xx_get_cca_threshold(dev);
+                res = sizeof(int8_t);
+            }
+            break;
+
         default:
             res = -ENOTSUP;
     }
@@ -762,6 +772,15 @@ static int _set(gnrc_netdev_t *device, netopt_t opt, void *val, size_t len)
             }
             break;
 
+        case NETOPT_CCA_THRESHOLD:
+            if (len > sizeof(int8_t)) {
+                res = -EOVERFLOW;
+            } else {
+                at86rf2xx_set_cca_threshold(dev, *((int8_t *)val));
+                res = sizeof(int8_t);
+            }
+            break;
+
         default:
             res = -ENOTSUP;
     }

drivers/at86rf2xx/include/at86rf2xx_registers.h

@@ -18,6 +18,7 @@
  * @author      Thomas Eichinger <thomas.eichinger@fu-berlin.de>
  * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
  * @author      Kaspar Schleiser <kaspar@schleiser.de>
+ * @author      Kévin Roussel <Kevin.Roussel@inria.fr>
  */
 
 #ifndef AT86RF2XX_REGISTERS_H_
@@ -241,6 +242,15 @@ extern "C" {
 #define AT86RF2XX_PHY_CC_CCA_DEFAULT__CCA_MODE                  (0x20)
 /** @} */
 
+/**
+ * @brief   Bitfield definitions for the CCA_THRES register
+ * @{
+ */
+#define AT86RF2XX_CCA_THRES_MASK__CCA_ED_THRES                  (0x0F)
+
+#define AT86RF2XX_CCA_THRES_MASK__RSVD_HI_NIBBLE                (0xC0)
+/** @} */
+
 /**
  * @brief   Bitfield definitions for the PHY_TX_PWR register
  * @{

drivers/include/at86rf2xx.h

@@ -22,6 +22,7 @@
  * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
  * @author      Kaspar Schleiser <kaspar@schleiser.de>
  * @author      Daniel Krebs <github@daniel-krebs.net>
+ * @author      Kévin Roussel <Kevin.Roussel@inria.fr>
  */
 
 #ifndef AT86RF2XX_H_
@@ -80,6 +81,11 @@ extern "C" {
  */
 #define AT86RF2XX_DEFAULT_TXPOWER       (0U)
 
+/**
+ * @brief   Base (minimal) RSSI value in dBm
+ */
+#define RSSI_BASE_VAL                   (-91)
+
 /**
  * @brief   Flags for device internal states (see datasheet)
  * @{
@@ -377,6 +383,23 @@ void at86rf2xx_set_csma_backoff_exp(at86rf2xx_t *dev, uint8_t min, uint8_t max);
  */
 void at86rf2xx_set_csma_seed(at86rf2xx_t *dev, uint8_t entropy[2]);
 
+/**
+ * @brief   Get the CCA threshold value
+ *
+ * @param[in] dev           device to read value from
+ *
+ * @return                  the current CCA threshold value
+ */
+int8_t at86rf2xx_get_cca_threshold(at86rf2xx_t *dev);
+
+/**
+ * @brief   Set the CCA threshold value
+ *
+ * @param[in] dev           device to write to
+ * @param[in] value         the new CCA threshold value
+ */
+void at86rf2xx_set_cca_threshold(at86rf2xx_t *dev, int8_t value);
+
 /**
  * @brief   Enable or disable driver specific options
  *