Instead of using the DTV properties cache directly, pass the get
frontend data as an argument. For now, everything should remain
the same, but the next patch will prevent get_frontend to
affect the global cache.

This is needed because several drivers don't care enough to only
change the properties if locked. Due to that, calling
G_PROPERTY before locking on those drivers will make them to
never lock. Ok, those drivers are crap and should never be
merged like that, but the core should not rely that the drivers
would be doing the right thing.
Reviewed-by: NMichael Ira Krufky <mkrufky@linuxtv.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

The Linux stack is short; we need to be able to count the number
of bytes used at stack on each function. So, we don't like to
use variable-length arrays, as complained by smatch:

	drivers/media/dvb-frontends/cxd2841er.c:205:19: warning: Variable length array is used.

The max usecase of the driver seems to be 15 bytes + 1 for the
register.

So, let's be safe and allocate 17 bytes for the write buffer.
This should be enough to cover all cases. If not, let's print
an error message.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/dvb-frontends/cxd2841er.c:992:5: warning: no previous prototype for 'cxd2841er_get_carrier_offset_t2' [-Wmissing-prototypes]
 int cxd2841er_get_carrier_offset_t2(
     ^
drivers/media/dvb-frontends/cxd2841er.c:1032:5: warning: no previous prototype for 'cxd2841er_get_carrier_offset_c' [-Wmissing-prototypes]
 int cxd2841er_get_carrier_offset_c(
     ^
drivers/media/dvb-frontends/cxd2841er.c:1360:5: warning: no previous prototype for 'cxd2841er_read_snr_t2' [-Wmissing-prototypes]
 int cxd2841er_read_snr_t2(struct cxd2841er_priv *priv, u32 *snr)
     ^
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Add DVB-C/T/T2/S/S2 demodulator frontend driver Sony CXD2841ER chip.
Signed-off-by: NKozlov Sergey <serjk@netup.ru>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>