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H A Dstv090x.c38670189 Sat Aug 29 10:02:57 CDT 2015 Joerg Riechardt <J.Riechardt@gmx.de> [media] stv090x: use lookup tables for carrier/noise ratio

The stv090x driver uses the lookup table for signal strength already,
with this patch we use the lookup tables for carrier/noise ratio as well.
This has the advantage, that values for DVB-S and DVB-S2 are now
corresponding, while before they were way off. The values are now
proportional to real carrier/noise ratio, while before they were
corresponding to register values. So now applications are able to give
the user real carrier/noise ratio.

Because the output has to be within 0x0000...0xFFFF the three negative
values for DVB-S2 are omitted. This is no significant loss, because
reception is lost at 7.5 dB already (TT S2-1600, Cine S2), so the
negative values are not really important, and also for DVB-S they don´t
exist.

Signed-off-by: Joerg Riechardt <j.riechardt@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
38670189 Sat Aug 29 10:02:57 CDT 2015 Joerg Riechardt <J.Riechardt@gmx.de> [media] stv090x: use lookup tables for carrier/noise ratio

The stv090x driver uses the lookup table for signal strength already,
with this patch we use the lookup tables for carrier/noise ratio as well.
This has the advantage, that values for DVB-S and DVB-S2 are now
corresponding, while before they were way off. The values are now
proportional to real carrier/noise ratio, while before they were
corresponding to register values. So now applications are able to give
the user real carrier/noise ratio.

Because the output has to be within 0x0000...0xFFFF the three negative
values for DVB-S2 are omitted. This is no significant loss, because
reception is lost at 7.5 dB already (TT S2-1600, Cine S2), so the
negative values are not really important, and also for DVB-S they don´t
exist.

Signed-off-by: Joerg Riechardt <j.riechardt@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>