Re: Nxt6000 frontend

[patrick.boettcher at desy.de (Patrick Boettcher)]

On Sat, 3 Feb 2007, Manu Abraham wrote:
> > No fixing needed, when used correctly: The mt2060-tuner was implemented to
> > use any gate (or repeater) transparently. I.e. there is an i2c-adapter in
> > frontend (today: dib3000, 7000x) which opens and closes the gate when
> > there is an I2C-message is transferred.
> 
> 
> IMHO, it is a demodulator driver that which implements the
> i2c_gate_ctrl for tuners behind a switched bus behind the same. In
> such a case, if what i probably understood is there is no need to use
> the callback itself to be used inside the demod driver, but whereas
> the function can called straight away within the demod driver.
> 
> ie, we need to use the callback only when used outside the demod
> driver, for example a tuner.

In the dib*-demod-drivers and their i2c-adapter I just put the open/close 
i2c-message around the tuners i2c-message(s) and transfer them all on the 
demod's i2c-bus. The locking of this I2C-bus will prevent conditions where 
the gate is open on both demods on the main bus.

> How does the hardware handle this ? for example, if you simply enable
> the repeater on the demodulator, both the tuners will be active for a
> diversity receiver.

Each tuner is connected to the tuner-i2c-bus of its demod. With the 
mechanism I don't have any problems.

Patrick.