nimble/ll: Add DTM extension for unmodulated carrier

This may be useful for HW validation. Implemented for nRF5x driver
based on Nordic DTM sample.

nimble/controller/include/controller/ble_phy.h

@@ -238,6 +238,9 @@ static inline int ble_ll_phy_to_phy_mode(int phy, int phy_options)
 #if MYNEWT_VAL(BLE_LL_DTM)
 void ble_phy_enable_dtm(void);
 void ble_phy_disable_dtm(void);
+#if MYNEWT_VAL(BLE_LL_DTM_EXTENSIONS)
+int ble_phy_dtm_carrier(uint8_t rf_channel);
+#endif
 #endif
 
 #ifdef __cplusplus

nimble/controller/src/ble_ll_dtm.c

@@ -342,6 +342,18 @@ ble_ll_dtm_tx_create_ctx(uint8_t packet_payload, uint8_t len,
     case 0x07:
         byte_pattern = 0xAA;
         break;
+#if MYNEWT_VAL(BLE_LL_DTM_EXTENSIONS)
+    case 0xff:
+        ble_ll_tx_power_set(g_ble_ll_tx_power);
+        rc = ble_phy_dtm_carrier(channel_rf_to_index[rf_channel]);
+        if (rc) {
+            return 1;
+        }
+
+        /* this is special as it doesn't involve scheduling */
+        g_ble_ll_dtm_ctx.active = 1;
+        return 0;
+#endif
     default:
         return 1;
     }
@@ -478,10 +490,20 @@ ble_ll_dtm_tx_test(uint8_t tx_chan, uint8_t len, uint8_t packet_payload,
         return BLE_ERR_INV_HCI_CMD_PARMS;
     }
 
-    if (tx_chan > 0x27 || packet_payload > 0x07) {
+    if (tx_chan > 0x27) {
         return BLE_ERR_INV_HCI_CMD_PARMS;
     }
 
+    if (packet_payload > 0x07) {
+#if MYNEWT_VAL(BLE_LL_DTM_EXTENSIONS)
+        if (packet_payload != 255) {
+            return BLE_ERR_INV_HCI_CMD_PARMS;
+        }
+#else
+        return BLE_ERR_INV_HCI_CMD_PARMS;
+#endif
+    }
+
     if (ble_ll_dtm_tx_create_ctx(packet_payload, len, tx_chan, phy_mode,
                                  interval, pkt_count)) {
         return BLE_ERR_UNSPECIFIED;

nimble/drivers/dialog_cmac/src/ble_phy.c

@@ -1796,4 +1796,12 @@ ble_phy_disable_dtm(void)
 {
     g_ble_phy_data.phy_whitening = 1;
 }
+
+#if MYNEWT_VAL(BLE_LL_DTM_EXTENSIONS)
+int
+ble_phy_dtm_carrier(uint8_t rf_channel)
+{
+    return 1;
+}
+#endif
 #endif

nimble/drivers/nrf5x/src/ble_phy.c

@@ -2286,6 +2286,22 @@ void ble_phy_disable_dtm(void)
     /* Enable whitening */
     NRF_RADIO->PCNF1 |= RADIO_PCNF1_WHITEEN_Msk;
 }
+
+#if MYNEWT_VAL(BLE_LL_DTM_EXTENSIONS)
+int
+ble_phy_dtm_carrier(uint8_t rf_channel)
+{
+    /* based on Nordic DTM sample */
+    ble_phy_disable();
+    ble_phy_enable_dtm();
+    ble_phy_mode_apply(BLE_PHY_MODE_1M);
+    nrf_radio_shorts_enable(NRF_RADIO, NRF_RADIO_SHORT_READY_START_MASK);
+    NRF_RADIO->FREQUENCY = g_ble_phy_chan_freq[rf_channel];
+    nrf_radio_task_trigger(NRF_RADIO, NRF_RADIO_TASK_TXEN);
+
+    return 0;
+}
+#endif
 #endif
 
 void