Improve tuner precision by calculating the VCO divisor at full precision, not
at kHz resolution. Also replace the manual divison loop with a simpler
fixed-point calculation.
In future blog v4 production batches (out in several months time), it
will be possible to turn off the upconverter when tuned outside of the
HF bands. The code controls the GPIOs to turn off the upconverter
when it is not in use.
In r82xx_read, there is a 1-byte I2C write followed by the I2C read. If
this I2C write fails, r82xx_read correctly bails out but may return 0.
Callers that check whether (rc < 0) will assume that the buffer was written
when it has not been, e.g. in r82xx_set_tv_standard where
priv->fil_cal_code = data[4] & 0x0f;
consumes a garbage value for data[4].
This change resolves that issue by copying the error path from r82xx_write.
As pointed out by Carl Laufer on the mailing list,
turning the loop-through output off reduces the
current consumption by 10-20mA which in turn reduces
the heat a bit. So far there seem to be no devices
that have anything connected to the loop-through output.
Signed-off-by: Steve Markgraf <steve@steve-m.de>
This improves SDR performence for nearby channel interference.
As a sideeffect also improves dynamic range becase ADC is not overloaded
by onwanted singlas.
Signed-off-by: Steve Markgraf <steve@steve-m.de>
Sultan Qasim Khan
Steve Markgraf