Provide a DVBv5 API signal strength. This is in units of 0.001 dBm rather
than a percentage.
>From Antti Palosaari's testing with a signal generator, it appears that the
gain calculated according to Montage's specification if negated is a
reasonable representation of the signal strength of the generator.
To this end:
(1) Polled statistic gathering needed to be implemented in the TS2020 driver.
This is done in the ts2020_stat_work() function.
(2) The calculated gain is placed as the signal strength in the
dtv_property_cache associated with the front end with the scale set to
FE_SCALE_DECIBEL.
(3) The DVBv3 format signal strength then needed to be calculated from the
signal strength stored in the dtv_property_cache rather than accessing
the value when ts2020_read_signal_strength() is called.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
3366cd5d72