Prepare the tekpower-dmm driver to be able to support various simple
serial port based DMMs.
Also, make a 'tekpower-tp4000zc' "first-class" driver which is currently
the only user of this generic driver.
The 'uni-t-dmm' driver/directory will not appear as a "driver" to
frontends anymore, it's just an internal thing.
The frontends will see a uni-t-ut61d and voltcraft-vc820 driver now,
with the correct names and parsers etc. attached to them.
This is not fully finished yet, but it's a start (and works mostly):
$ sigrok-cli -D
The following devices were found:
UNI-T UT61D with 1 probe: P1
Voltcraft VC-820 with 1 probe: P1
$ sigrok-cli --driver voltcraft-vc820 -D
The following devices were found:
Voltcraft VC-820 with 1 probe: P1
$ sigrok-cli --driver uni-t-ut61d -D
The following devices were found:
UNI-T UT61D with 1 probe: P1
# Now attaching a UNI-T UT61D device via USB.
$ sigrok-cli --driver uni-t-ut61d --samples 3 -O analog
P1: -0.017800 V DC
P1: -0.017600 V DC
P1: -0.017700 V DC
# Now attaching a Voltcraft VC-820 device via USB instead.
$ sigrok-cli --driver voltcraft-vc820 --samples 3 -O analog
P1: -0.319200 V DC
P1: -0.319300 V DC
P1: -0.319300 V DC
To find a driver or device option by name, the sr_drvopt_name_get() and
sr_devopt_name_get() calls are now available. This was the only reason the
driver and device struct sr_hwcap_option arrays were published.
There is no point in libsigrok copying probe lists around. The driver now
builds a list of probes according to the model device it found, and will
make that available to a frontend. The frontend thus has a reference of
what the driver has, including default names, and doesn't need libsigrok
to provide an unnecessary level of abstraction.
The sr_probe_new() library-private function is a helper for drivers.
init() now only does whatever administrative stuff it needs (typically not
much), and returns an error code.
scan() can be called multiple times during the life of an application, and
returns a GSList of struct sr_dev_inst * of devices found during that scan.
The instances are a copy of the ones stored in the driver's own instance
list, to be freed by the caller with g_slist_free() only.
The scan() call can be passed a GSList of struct sr_hwopt *, to direct the
scanning.
SR_HWOPT_* entries are driver options, not device instance parameters, so
they will never be mixed together.
Also, driver options are always passed in a GSList, where the data field
is a struct sr_hwopt.
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.