mpm: fix ref_locked sensor on n320

The ref_locked mboard sensor on the n320 always returned true without
querying hardware. On this device family, mboard sensor callback in
n3xx.py returns the "and" of its daughterboard LMK PLLs by querying the
get_ref_lock() function on each dboard manager. However, that function
only existed for the Magnesium daughterbaord. For the Rhodium
daughterboard, the function didn't exist and so a true value was
automatically returned.

This commit adds the get_ref_lock() implementations for Rhodium and
EISCAT daughterboards, which are identical to the implementation
already present for Magnesium.

Co-authored-by: Martin Braun <martin.braun@ettus.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/mpm/python/usrp_mpm/dboard_manager/rhodium.py b/mpm/python/usrp_mpm/dboard_manager/rhodium.py
index e80b33d25..93b9f2186 100644
--- a/mpm/python/usrp_mpm/dboard_manager/rhodium.py
+++ b/mpm/python/usrp_mpm/dboard_manager/rhodium.py
@@ -454,6 +454,21 @@ class Rhodium(BfrfsEEPROM, DboardManagerBase):
         " Return master clock rate (== sampling rate / 2) "
         return self.master_clock_rate
 
+    def get_ref_lock(self):
+        """
+        Returns True if the LMK reference is locked.
+
+        Note: This does not return a sensor dict. The sensor API call is
+        in the motherboard class.
+        """
+        if self.lmk is None:
+            self.log.trace("LMK object not yet initialized, defaulting to " \
+                           "no ref locked!")
+            return False
+        lmk_lock_status = self.lmk.check_plls_locked()
+        self.log.trace("LMK lock status is: {}".format(lmk_lock_status))
+        return lmk_lock_status
+
     def update_ref_clock_freq(self, freq, **kwargs):
         """
         Call this function if the frequency of the reference clock changes