In non S2 mode, the device is able to autodetect inversion. So
let's store it for tuning to S2 transponders.
Signed-off-by: Reinhard Nißl <rnissl@gmx.de>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Usually, inversion doesn't change in a system. Storing the last
successful inversion value speeds up tuning of DVB-S2 transponders.
Signed-off-by: Reinhard Nißl <rnissl@gmx.de>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Throughout the zig-zag-implementations, inversion is taken into
account when reading and writing the CFR register, which contains
the derotator frequency. As swapping IQ signals changes the sign
of that register for example, the idea is to compensate that sign
change by multiplying the register value with the inversion enum
value.
The current enum values 0 and 1 for IQ_SWAP_OFF and IQ_SWAP_ON
don't work in the case IQ_SWAP_OFF, due to the multiplication by
zero (I've only found a single device which actually uses
IQ_SWAP_OFF in it's config).
I've changed the enum values to +1 and -1 to accommodate to the
intended usage.
Signed-off-by: Reinhard Nißl <rnissl@gmx.de>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
It seems that current inversion handling addresses only the signal
routing on the PCB, i. e. IQ signals are either swapped or not.
But when the device is operated in a Satellite Channel Router (SCR)
environment, an additional inversion is required due to the way how
the SCR works. Therefore it makes sense to me to always enable auto
inversion handling and drop the enum value IQ_SWAP_AUTO.
Signed-off-by: Reinhard Nißl <rnissl@gmx.de>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Contrary to the chip's specs, the register's value is signed, so we
need to sign extend the value before using it in calculations like
when determining the offset frequency.
Signed-off-by: Reinhard Nißl <rnissl@gmx.de>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Raise the DVB frontends one level up, as the intention is to remove
the drivers/media/dvb directory.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
