gpsd connection is not reliable.
Adding more error handling to re-connect during polling.
Add control flows to get_gps_time in order to give an effect of getting
the value on pps edge.
- This is a combination of 5 commits.
- rh: add lo distribution board gpio expander
- rh: add lo distribution mpm functions
- rh: add code to conditionally initialize lo distribution
- rh: change empty i2c device from exception to assertion
- rh: add lo distribution board control
- Confirmed the Phase DAC to be initialized at mid-scale.
- Confirmed the Phase DAC step resolution for fine clock shifting.
The clock synchronization algorithm relies on the Phase DAC to fine
shift the sampling clocks on each daughterboard.
Only a certain number of DAC codes are required for the actual clock
adjustment, thus a different range of codes may be chosen by
initializing the Phase DAC with a given value. With the selected range,
one may measure the Phase DAC's linearity and step resolution, which
defines how many steps are required when performing the fine shifting
of the clocks.
After initializing the 16-bit Phase DAC at 25%, 50% (mid-scale), and
75%; it was found that the clock distribution PLL locks relatively
faster when using mid-scale (2^15). By testing the Phase DAC's
linearity, it was confirmed that the circuit resolution is 1.11 ps per
code.
- Optimized JESD204B RX/TX links' latency.
- Made JESD latency constant across supported frequencies.
- Checking RX SYSREF capture in the FPGA deframer block.
The JESD204B standard can be linked in such a way to produce a
repeatable, deterministic delay from the framer to deframer. This is
accomplished by setting up a LMFC (local multiframe clock) in both
devices.
The LMFCs are reset whenever a SYSREF edge is captured by the framer
and deframer. Therefore, it is simple to control the LMFC rising edges
in each device by implementing variable delay elements on the SYSREF
pulses to the framer and deframer.
Latency across the JESD204B TX/RX links should remain constant and
deterministic across the supported sampling_clock_rate values. By
testing the roundtrip latency (i.e. FPGA -> TX -> RX -> FPGA) with
different delay values in the FPGA, one may decrease the latency and
provide enough setup and hold margin for the data to be transfered
through each JESD link.
It was found that a different set of SYSREF delay values are required
for sampling_clock_rate = 400 MSPS to match the latency of the other
supported rates.
Add coercing behavior to set_time_source and set_clock_source to
a valid sync source. Also, skip set_sync_source if device already
set to the corresponding one.
Summary:
This change will allow correct args to pass from mboard to dboards,
that in turn can be useful for dboard manager.
Details:
In N310, the dboard manager needs the time source to be updated before
calling update_ref_clock_source(), because it will trigger a reinit of
the dboard, for which the time_source is essential to determine correct
clock synchronizer settings.
The special case is the white rabbit time source needs a different
internal ref_clock_frequency for the clock synchronizer than the passed
in ref_clock_freq.
This provides a new utility for MPM devices (usrp_update_fs.py), which
goes through all the necessary steps to update a filesystem.
Will trigger a mender update, but the tool is not specific to Mender
and can be changed to use other methods in the future.
When reloading the Periph Manager (as when we run the image loader),
we need to run the RPCServer `__init__` function in order to reset the
cache of RPC methods. Otherwise, that cache keeps stale references to
old functions (and prevents garbage collection).
It may be possible to reset the method cache some other way, but the
`_methods` attribute of RPCServer is Cython, and doesn't seem to be
accessible in our Python code.
Adding MPM Git hash and version to the MPM device info. This
information is currently only available through logs when MPM starts
(it is the first log message in usrp_hwd.py). Adding it to the device
info makes it accessible to any application which checks that, such as
uhd_usrp_probe.
- For different ref clock frequencies, the ref_counter should change
and not the n_counter.
- The charge pump should be set to normal mode and tristate as that
would prevent the PLL to lock.
- ref_clock_(int/ext) test was not changing adf400x driver settings
for new ref clock frequency. Therefore, changed the implementation
to use uhd_usrp_probe --sensor to set clock_source and get
'ref_locked' sensor value
Added set_sync_source method to set both the time and clock sources
without forcing a re-init twice. Modified the existing set_time_source
and set_clock_source methods to call into set_sync_source.
