x300: Enable power reference API

This enables the power calbration API for X300 and X310. The
uhd_power_cal.py script will be able to create calibration files for
X300 series USRPs.

The multi_usrp calls *_power_reference  will be functional, assuming
there is calibration data available for the given system.

3 files changed, 100 insertions, 2 deletions

diff --git a/host/docs/twinrx.dox b/host/docs/twinrx.dox
index 2175c13ff..d8dd20f6d 100644
--- a/host/docs/twinrx.dox
+++ b/host/docs/twinrx.dox
@@ -101,5 +101,33 @@ gain on the second channel could be significantly lower or higher than expected.
 will increase in comparison to the direct antenna mapping so the phase of the received signal will be different
 depending on the antenna mapping.
 
+\subsection twinrx_power_cal Power Calibration
+
+The X300/X310 motherboards support power-calibrating the daughterboards, and
+therefore TwinRX can also make use of this calibration API (see also \ref page_power).
+
+However, unlike other daughterboards, the relationship between actual, received
+power, and power measured at the ADC depend on more parameters than with the
+other daughterboards. First of all, the TwinRX has two complete analog receiver
+chains, unlike all the other daughterboards. Both receiver chains can be connected
+to any RF input, which already increases the number of combinations that need to
+be calibrated. Furthermore, the RF paths inside the daughterboard have an
+optional switch, which allows both receivers to receive from the same input, at
+different frequencies.
+
+
+single chan
+
+x3xx_power_cal_rx_rx1 + serial:{0, 1}
+x3xx_power_cal_rx_rx2 + serial:{0, 1}
+
+dual chan
+
+
+x3xx_power_cal_rx_rx1 + serial:{00, 11}
+x3xx_power_cal_rx_rx2 + serial:{00, 11}
+
+
+
 */
 // vim:ft=doxygen:
diff --git a/host/docs/usrp_x3x0.dox b/host/docs/usrp_x3x0.dox
index 54b0043f3..c95ddd1b9 100644
--- a/host/docs/usrp_x3x0.dox
+++ b/host/docs/usrp_x3x0.dox
@@ -773,6 +773,15 @@ Further information on how to use Chipscope can be found in the Xilinx Chipscope
 
 \section x3x0_misc Miscellaneous
 
+\subsection x3x0_misc_power Power API
+
+The X300 series support the UHD power calibration API (see: \ref page_power).
+Calibration data is daughterboard-specific, i.e., the daughterboard serial is
+used to map calibration data to a serial.
+
+Daughterboards have to be manually calibrated using a calibrated power meter or
+signal generator.
+
 \subsection x3x0_misc_settings Configuring the device in an application
 
 During runtime, the device can be configured in several different ways.
diff --git a/host/lib/usrp/x300/x300_radio_control.cpp b/host/lib/usrp/x300/x300_radio_control.cpp
index 7c15554af..cdac71d52 100644
--- a/host/lib/usrp/x300/x300_radio_control.cpp
+++ b/host/lib/usrp/x300/x300_radio_control.cpp
@@ -78,6 +78,7 @@ size_t _get_chan_from_map(std::unordered_map<size_t, map_type> map, const std::s
 }
 
 constexpr double DEFAULT_RATE = 200e6;
+constexpr char HW_GAIN_STAGE[] = "hw";
 
 } // namespace
 
@@ -147,7 +148,7 @@ public:
         // Note: ADC calibration and DAC sync happen in x300_mb_controller
         _init_codecs();
         _x300_mb_control->register_reset_codec_cb([this]() { this->reset_codec(); });
-        // FP-GPIO
+        // FP-GPIO (the gpio_atr_3000 ctor will initialize default values)
         RFNOC_LOG_TRACE("Creating FP-GPIO interface...");
         _fp_gpio = gpio_atr::gpio_atr_3000::make(_wb_iface,
             x300_regs::SR_FP_GPIO,
@@ -421,6 +422,7 @@ public:
 
     double set_tx_gain(const double gain, const std::string& name, const size_t chan)
     {
+        _tx_pwr_mgr.at(chan)->set_tracking_mode(pwr_cal_mgr::tracking_mode::TRACK_GAIN);
         if (_tx_gain_groups.count(chan)) {
             auto& gg = _tx_gain_groups.at(chan);
             gg->set_value(gain, name);
@@ -436,6 +438,7 @@ public:
 
     double set_rx_gain(const double gain, const std::string& name, const size_t chan)
     {
+        _rx_pwr_mgr.at(chan)->set_tracking_mode(pwr_cal_mgr::tracking_mode::TRACK_GAIN);
         auto& gg = _rx_gain_groups.at(chan);
         gg->set_value(gain, name);
         return radio_control_impl::set_rx_gain(gg->get_value(name), chan);
@@ -1557,11 +1560,12 @@ private:
             && boost::starts_with(
                    get_tree()->access<std::string>(DB_PATH / "rx_frontends/0/name").get(),
                    "TwinRX")) {
+            _twinrx = true;
             set_num_input_ports(0);
         }
         RFNOC_LOG_TRACE("Num Active Frontends: RX: " << get_num_output_ports()
                                                      << " TX: " << get_num_input_ports());
-    }
+    } // _init_db()
 
     void _init_dboards()
     {
@@ -1682,6 +1686,62 @@ private:
             }
             _rx_gain_groups[chan] = gg;
         }
+
+        ////////////////////////////////////////////////////////////////
+        // Load calibration data
+        ////////////////////////////////////////////////////////////////
+        RFNOC_LOG_TRACE("Initializing power calibration data...");
+        // RX and TX are symmetric, so we use a macro to avoid some duplication
+#define INIT_POWER_CAL(dir)                                                             \
+    {                                                                                   \
+        const std::string DIR  = (#dir == std::string("tx")) ? "TX" : "RX";             \
+        const size_t num_ports = (#dir == std::string("tx")) ? get_num_input_ports()    \
+                                                             : get_num_output_ports();  \
+        _##dir##_pwr_mgr.resize(num_ports);                                             \
+        for (size_t chan = 0; chan < num_ports; chan++) {                               \
+            const auto eeprom =                                                         \
+                get_tree()->access<dboard_eeprom_t>(DB_PATH / (#dir "_eeprom")).get();  \
+            /* The cal serial is the daughterboard serial plus the FE name */           \
+            const std::string cal_serial =                                              \
+                eeprom.serial + "#" + _##dir##_fe_map.at(chan).db_fe_name;              \
+            /* Now create a gain group for this. _?x_gain_groups won't work, */         \
+            /* unfortunately, because it doesn't group the gains we want them to */     \
+            /* be grouped. */                                                           \
+            auto ggroup = uhd::gain_group::make();                                      \
+            ggroup->register_fcns(HW_GAIN_STAGE,                                        \
+                {[this, chan]() { return get_##dir##_gain_range(chan); },               \
+                    [this, chan]() { return get_##dir##_gain(chan); },                  \
+                    [this, chan](const double gain) { set_##dir##_gain(gain, chan); }}, \
+                10 /* High priority */);                                                \
+            /* If we had a digital (baseband) gain, we would register it here, so */    \
+            /* that the power manager would know to use it as a backup gain stage. */   \
+            _##dir##_pwr_mgr.at(chan) = pwr_cal_mgr::make(                              \
+                cal_serial,                                                             \
+                "X300-CAL-" + DIR,                                                      \
+                [this, chan]() { return get_##dir##_frequency(chan); },                 \
+                [this, chan]() -> std::string {                                         \
+                    const auto id_path = get_db_path(#dir, chan) / "id";                \
+                    const std::string db_suffix =                                       \
+                        get_tree()->exists(id_path)                                     \
+                            ? get_tree()->access<std::string>(id_path).get()            \
+                            : "generic";                                                \
+                    const std::string ant = get_##dir##_antenna(chan);                  \
+                    return "x3xx_pwr_" + db_suffix + "_" + #dir + "_"                   \
+                           + pwr_cal_mgr::sanitize_antenna_name(ant);                   \
+                },                                                                      \
+                ggroup);                                                                \
+            /* Every time we retune, we need to re-set the power level, if */           \
+            /* we're in power tracking mode */                                          \
+            get_tree()                                                                  \
+                ->access<double>(get_db_path(#dir, chan) / "freq" / "value")            \
+                .add_coerced_subscriber([this, chan](const double) {                    \
+                    _##dir##_pwr_mgr.at(chan)->update_power();                          \
+                });                                                                     \
+        }                                                                               \
+    } // end macro
+
+        INIT_POWER_CAL(tx);
+        INIT_POWER_CAL(rx);
     } /* _init_dboards */
 
     void _set_db_eeprom(i2c_iface::sptr i2c,
@@ -1910,6 +1970,7 @@ private:
 
     bool _basic_lf_rx = false;
     bool _basic_lf_tx = false;
+    bool _twinrx = false;
 
     std::unordered_map<size_t, rx_fe_perif> _rx_fe_map;
     std::unordered_map<size_t, tx_fe_perif> _tx_fe_map;