In the case of USB drivers, a driver's dev_acquisition_stop() cannot
simply remove its fd sources from the session and close its devices:
a USB transfer might still be underway, and it needs to be finished
(and its memory freed) properly.
An sr_dev_inst->status value is added: SR_ST_STOPPING, which should
be set when the driver's dev_acquisition_stop() is called, and acts
as a marker for the USB event handler to wind up its operations.
In order for dev_acquisition_stop() to be able to set the sdi status,
however, it needs to be unconstified.
These are used to list the device instances currently known to the driver,
and clear that list.
Drivers that don't necessarily clear their list of instances on every scan,
such as genericdmm, need to provide these to the frontend to keep instance
management sane.
Since probes now live in a struct sr_dev_inst owned by the driver, it
already knows about them. Instead of a frontend telling the driver to
configure probes, all driver now do this just before starting acquisition.
It's obsolete: no frontend ever used it, and neither did libsigrok.
The sdi->status field is only used internally by some drivers, and
should probably be moved to the driver-specific context structs.
This changes the semantics of the init() call as well. That now only
initializes the driver -- an administrative affair, no hardware gets
touched during this call. It returns a standard SR_OK or SR_ERR* code.
The scan() call does a discovery run for devices it knows, and returns
the number found. It can be called at any time.
It was actually used in one way: the session file loaded abused it for
passing in the filename -- something it definitely wasn't intended for.
This now uses the proper way to pass arguments to a driver: the new
SR_HWCAP_SESSIONFILE.
The OLS driver could also use it as an indication of the serial port to
use instead of actively probing all serial ports on the system, but there
wasn't any frontend code that passed in such a parameter, making it
entirely useless. That will soon be handled differently with the new
scan() API call, regardless.
All frontends will have to include <libsigrok/libsigrok.h> from now on.
This header includes proto.h and version.h, both installed from the
distribution into $INCLUDE/libsigrok/ as well.
The only dynamically changed header is now version.h, which has both
libsigrok and libtool compile-time versions in it.
Samples received before the trigger point are stored. From the
trigger point on, every chunk received from the device is sent
up the session bus. After the device has finished sending, the
stored samples are transmitted.
MQ is the measured quantity, e.g. voltage, current, temperature.
UNIT is the unit in which these quantities are measured, e.g. volt,
ampere, celsius, kelvin, etc. etc.
The same MQ can be specified in different UNITs by the driver, depending
on what the hardware reports. Conversion is left to the frontends.
Not yet used, but it's the key to knowing where in the frame to
start displaying; the frame is used as a circular buffer, and what
is sent is effectively a snapshot.
The ntohs() from <arpa/inet.h> is not available on MinGW/Windows. There
are ways to work around this, but as we use glib already, using g_ntohs()
is the best option anyway.
Peter Stuge
Uwe Hermann
Bert Vermeulen