ad9361: rssi readout

4 files changed, 40 insertions, 2 deletions

diff --git a/host/lib/usrp/common/ad9361_ctrl.cpp b/host/lib/usrp/common/ad9361_ctrl.cpp
index c84fcee39..f94536ed9 100644
--- a/host/lib/usrp/common/ad9361_ctrl.cpp
+++ b/host/lib/usrp/common/ad9361_ctrl.cpp
@@ -148,7 +148,7 @@ public:
         return _device.tune(direction, value);
     }
 
-    //! turn on/off Catalina's data port loopback
+    //! turn on/off data port loopback
     void data_port_loopback(const bool on)
     {
         boost::lock_guard<boost::mutex> lock(_mutex);
@@ -156,6 +156,15 @@ public:
         _device.data_port_loopback(on);
     }
 
+    //! read internal RSSI sensor
+    sensor_value_t get_rssi(const std::string &which)
+    {
+        boost::lock_guard<boost::mutex> lock(_mutex);
+
+        ad9361_device_t::chain_t chain =_get_chain_from_antenna(which);
+        return sensor_value_t("RSSI", _device.get_rssi(chain), "dB");
+    }
+
 private:
     static ad9361_device_t::direction_t _get_direction_from_antenna(const std::string& antenna)
     {
diff --git a/host/lib/usrp/common/ad9361_ctrl.hpp b/host/lib/usrp/common/ad9361_ctrl.hpp
index 93d697349..16e1d23eb 100644
--- a/host/lib/usrp/common/ad9361_ctrl.hpp
+++ b/host/lib/usrp/common/ad9361_ctrl.hpp
@@ -21,6 +21,7 @@
 #include <uhd/transport/zero_copy.hpp>
 #include <uhd/types/ranges.hpp>
 #include <uhd/types/serial.hpp>
+#include <uhd/types/sensors.hpp>
 #include <boost/shared_ptr.hpp>
 #include <ad9361_device.h>
 #include <string>
@@ -94,8 +95,11 @@ public:
     //! tune the given frontend, return the exact value
     virtual double tune(const std::string &which, const double value) = 0;
 
-    //! turn on/off Catalina's data port loopback
+    //! turn on/off data port loopback
     virtual void data_port_loopback(const bool on) = 0;
+
+    //! read internal RSSI sensor
+    virtual sensor_value_t get_rssi(const std::string &which) = 0;
 };
 
 }}
diff --git a/host/lib/usrp/common/ad9361_driver/ad9361_device.cpp b/host/lib/usrp/common/ad9361_driver/ad9361_device.cpp
index d56cedec9..b5e116a70 100644
--- a/host/lib/usrp/common/ad9361_driver/ad9361_device.cpp
+++ b/host/lib/usrp/common/ad9361_driver/ad9361_device.cpp
@@ -1911,4 +1911,26 @@ void ad9361_device_t::data_port_loopback(const bool loopback_enabled)
     _io_iface->poke8(0x3F5, (loopback_enabled ? 0x01 : 0x00));
 }
 
+/* Read back the internal RSSI measurement data. The result is in dB
+ * but not in absolute units. If absolute units are required
+ * a bench calibration should be done.
+ * -0.25dB / bit 9bit resolution.*/
+double ad9361_device_t::get_rssi(chain_t chain)
+{
+    boost::uint32_t reg_rssi = 0;
+    boost::uint8_t lsb_bit_pos = 0;
+    if (chain == CHAIN_1) {
+        reg_rssi = 0x1A7;
+        lsb_bit_pos = 0;
+    }else {
+        reg_rssi = 0x1A9;
+        lsb_bit_pos = 1;
+    }
+    boost::uint8_t msbs = _io_iface->peek8(reg_rssi);
+    boost::uint8_t lsb = ((_io_iface->peek8(0x1AB)) >> lsb_bit_pos) & 0x01;
+    boost::uint16_t val = ((msbs << 1) | lsb);
+    double rssi = (-0.25f * ((double)val)); //-0.25dB/lsb (See Gain Control Users Guide p. 25)
+    return rssi;
+}
+
 }}
diff --git a/host/lib/usrp/common/ad9361_driver/ad9361_device.h b/host/lib/usrp/common/ad9361_driver/ad9361_device.h
index 41af2eeea..8c163572c 100644
--- a/host/lib/usrp/common/ad9361_driver/ad9361_device.h
+++ b/host/lib/usrp/common/ad9361_driver/ad9361_device.h
@@ -63,6 +63,9 @@ public:
     /* Turn on/off AD9361's TX port --> RX port loopback. */
     void data_port_loopback(const bool loopback_enabled);
 
+    /* Read back the internal RSSI measurement data. */
+    double get_rssi(chain_t chain);
+
     //Constants
     static const double AD9361_MAX_GAIN;
     static const double AD9361_MAX_CLOCK_RATE;