Add platform API to check state of the radio. (#1413)

examples/platforms/nrf52840/radio.c

@@ -188,6 +188,34 @@ void nrf5RadioInit(void)
     nrf_drv_radio802154_init();
 }
 
+PhyState otPlatRadioGetState(otInstance *aInstance)
+{
+    (void) aInstance;
+
+    if (sDisabled)
+    {
+        return kStateDisabled;
+    }
+
+    switch (nrf_drv_radio802154_state_get())
+    {
+    case NRF_DRV_RADIO802154_STATE_SLEEP:
+        return kStateSleep;
+
+    case NRF_DRV_RADIO802154_STATE_RECEIVE:
+    case NRF_DRV_RADIO802154_STATE_ENERGY_DETECTION:
+        return kStateReceive;
+
+    case NRF_DRV_RADIO802154_STATE_TRANSMIT:
+        return kStateTransmit;
+
+    default:
+        assert(false); // Make sure driver returned valid state.
+    }
+
+    return kStateReceive; // It is the default state. Return it in case of unknown.
+}
+
 ThreadError otPlatRadioEnable(otInstance *aInstance)
 {
     (void) aInstance;

include/openthread/platform/radio.h

@@ -200,6 +200,19 @@ void otPlatRadioSetShortAddress(otInstance *aInstance, uint16_t aShortAddress);
  *
  */
 
+/**
+ * Get current state of the radio.
+ *
+ * This function is not required by OpenThread. It may be used for debugging and/or application-specific purposes.
+ *
+ * @note This function may be not implemented. It does not affect OpenThread.
+ *
+ * @param[in] aInstance  The OpenThread instance structure.
+ *
+ * @return  Current state of the radio.
+ */
+PhyState otPlatRadioGetState(otInstance *aInstance);
+
 /**
  * Enable the radio.
  *

third_party/NordicSemiconductor/drivers/nrf_drv_radio802154.c

@@ -915,6 +915,31 @@ void nrf_drv_radio802154_init(void)
     irq_init();
 }
 
+nrf_drv_radio802154_state_t nrf_drv_radio802154_state_get(void)
+{
+    switch (m_state)
+    {
+    case RADIO_STATE_SLEEP:
+        return NRF_DRV_RADIO802154_STATE_SLEEP;
+
+    case RADIO_STATE_WAITING_RX_FRAME:
+    case RADIO_STATE_RX_HEADER:
+    case RADIO_STATE_RX_FRAME:
+    case RADIO_STATE_TX_ACK:
+        return NRF_DRV_RADIO802154_STATE_RECEIVE;
+
+    case RADIO_STATE_CCA:
+    case RADIO_STATE_TX_FRAME:
+    case RADIO_STATE_RX_ACK:
+        return NRF_DRV_RADIO802154_STATE_TRANSMIT;
+
+    case RADIO_STATE_ED:
+        return NRF_DRV_RADIO802154_STATE_ENERGY_DETECTION;
+    }
+
+    return NRF_DRV_RADIO802154_STATE_INVALID;
+}
+
 bool nrf_drv_radio802154_sleep(void)
 {
     bool result = true;

third_party/NordicSemiconductor/drivers/nrf_drv_radio802154.h

@@ -43,6 +43,18 @@
 extern "C" {
 #endif
 
+/**
+ * @brief States of the driver.
+ */
+typedef enum
+{
+    NRF_DRV_RADIO802154_STATE_INVALID,
+    NRF_DRV_RADIO802154_STATE_SLEEP,
+    NRF_DRV_RADIO802154_STATE_RECEIVE,
+    NRF_DRV_RADIO802154_STATE_TRANSMIT,
+    NRF_DRV_RADIO802154_STATE_ENERGY_DETECTION,
+} nrf_drv_radio802154_state_t;
+
 /**
  * @brief Initialize 802.15.4 driver.
  *
@@ -90,7 +102,7 @@ void nrf_drv_radio802154_short_address_set(const uint8_t *p_short_address);
 
 
 /**
- * @section Functions to request FSM transitions.
+ * @section Functions to request FSM transitions and check current state.
  *
  *          receive()       transmit()
  *          -------->       -------->
@@ -103,6 +115,11 @@ void nrf_drv_radio802154_short_address_set(const uint8_t *p_short_address);
  *               Energy detection
  */
 
+/**
+ * @brief Get current state of the radio.
+ */
+nrf_drv_radio802154_state_t nrf_drv_radio802154_state_get(void);
+
 /**
  * @brief Change radio state to Sleep.
  *