mpm: Added sensor API

- Motherboard sensors are automatically populated into the property
  tree, they can be automatically enumerated and queried
- Daughterboard sensors have an API for querying and enumerating
  sensors, but this commit does not automatically add them to the
  property tree

3 files changed, 106 insertions, 0 deletions

diff --git a/host/lib/usrp/mpmd/mpmd_impl.cpp b/host/lib/usrp/mpmd/mpmd_impl.cpp
index 38a089788..93e777af2 100644
--- a/host/lib/usrp/mpmd/mpmd_impl.cpp
+++ b/host/lib/usrp/mpmd/mpmd_impl.cpp
@@ -106,6 +106,36 @@ namespace {
                 );
             })
         ;
+
+        /*** Sensors ********************************************************/
+        auto sensor_list =
+            mb->rpc->request_with_token<std::vector<std::string>>(
+                "get_mb_sensors"
+            );
+        UHD_LOG_DEBUG("MPMD",
+            "Found " << sensor_list.size() << " motherboard sensors."
+        );
+        for (const auto& sensor_name : sensor_list) {
+            UHD_LOG_TRACE("MPMD",
+                "Adding motherboard sensor `" << sensor_name << "'"
+            );
+            tree->create<sensor_value_t>(
+                    mb_path / "sensors" / sensor_name)
+                .set_publisher([mb, sensor_name](){
+                    return sensor_value_t(
+                        mb->rpc->request_with_token<sensor_value_t::sensor_map_t>(
+                            "get_mb_sensor", sensor_name
+                        )
+                    );
+                })
+                .set_coercer([](const sensor_value_t &){
+                    throw uhd::runtime_error(
+                        "Trying to write read-only sensor value!"
+                    );
+                    return sensor_value_t("", "", "");
+                })
+            ;
+        }
     }
 
     void reset_time_synchronized(uhd::property_tree::sptr tree)
diff --git a/mpm/python/usrp_mpm/dboard_manager/base.py b/mpm/python/usrp_mpm/dboard_manager/base.py
index 56655f946..b87033860 100644
--- a/mpm/python/usrp_mpm/dboard_manager/base.py
+++ b/mpm/python/usrp_mpm/dboard_manager/base.py
@@ -34,6 +34,10 @@ class DboardManagerBase(object):
     # Very important: A list of PIDs that apply to the current device. Must be
     # list, even if there's only one entry.
     pids = []
+    # See PeriphManager.mboard_sensor_callback_map for a description.
+    rx_sensor_callback_map = {}
+    # See PeriphManager.mboard_sensor_callback_map for a description.
+    tx_sensor_callback_map = {}
     # A dictionary that maps chips or components to chip selects for SPI.
     # If this is given, a dictionary called self._spi_nodes is created which
     # maps these keys to actual spidev paths. Also throws a warning/error if
@@ -108,3 +112,37 @@ class DboardManagerBase(object):
         Call this function if the frequency of the reference clock changes.
         """
         self.log.warning("update_ref_clock_freq() called but not implemented")
+
+    def get_sensors(self, direction):
+        """
+        Return a list of RX daughterboard sensor names.
+
+        direction needs to be either RX or TX.
+        """
+        if direction.lower() == 'rx':
+            return list(self.rx_sensor_callback_map.keys())
+        else:
+            return list(self.tx_sensor_callback_map.keys())
+
+    def get_sensor(self, direction, sensor_name):
+        """
+        Return a dictionary that represents the sensor values for a given
+        sensor. If the requested sensor sensor_name does not exist, throw an
+        exception. direction is either RX or TX.
+
+        See PeriphManager.get_mb_sensor() for a description of the return value
+        format.
+        """
+        callback_map = \
+            rx_sensor_callback_map if direction.lower() == 'rx' \
+            else tx_sensor_callback_map
+        if sensor_name not in callback_map:
+            error_msg = "Was asked for non-existent sensor `{}'.".format(
+                sensor_name
+            )
+            self.log.error(error_msg)
+            raise RuntimeError(error_msg)
+        return getattr(
+            self, self.callback_map.get('sensor_name')
+        )()
+
diff --git a/mpm/python/usrp_mpm/periph_manager/base.py b/mpm/python/usrp_mpm/periph_manager/base.py
index 0aa1adf59..72066b9ef 100644
--- a/mpm/python/usrp_mpm/periph_manager/base.py
+++ b/mpm/python/usrp_mpm/periph_manager/base.py
@@ -93,6 +93,9 @@ class PeriphManagerBase(object):
     # particular version of MPM supports. Leave at None to skip a max rev
     # check.
     mboard_max_rev = None
+    # A list of available sensors on the motherboard. This dictionary is a map
+    # of the form sensor_name -> method name
+    mboard_sensor_callback_map = {}
     # This is a sanity check value to see if the correct number of
     # daughterboards are detected. If somewhere along the line more than
     # max_num_dboards dboards are found, an error or warning is raised,
@@ -461,3 +464,38 @@ class PeriphManagerBase(object):
             xbar_file.write(laddr_value)
         return True
 
+    def get_mb_sensors(self):
+        """
+        Return a list of sensor names.
+        """
+        return list(self.mboard_sensor_callback_map.keys())
+
+    def get_mb_sensor(self, sensor_name):
+        """
+        Return a dictionary that represents the sensor values for a given
+        sensor. If the requested sensor sensor_name does not exist, throw an
+        exception.
+
+        The returned dictionary has the following keys (all values are
+        strings):
+        - name: This is typically the same as sensor_name
+        - type: One of the following strings: BOOLEAN, INTEGER, REALNUM, STRING
+                Note that this matches uhd::sensor_value_t::data_type_t
+        - value: The value. If type is STRING, it is interpreted as-is. If it's
+                 REALNUM or INTEGER, it needs to be convertable to float or
+                 int, respectively. If it's BOOLEAN, it needs to be either
+                 'true' or 'false', although any string that is not 'true' will
+                 be interpreted as false.
+        - unit: This depends on the type. It is generally only relevant for
+                pretty-printing the sensor value.
+        """
+        if sensor_name not in self.get_mb_sensors():
+            error_msg = "Was asked for non-existent sensor `{}'.".format(
+                sensor_name
+            )
+            self.log.error(error_msg)
+            raise RuntimeError(error_msg)
+        return getattr(
+            self, self.mboard_sensor_callback_map.get(sensor_name)
+        )()
+