[linux-dvb] Problem about mt2131 tuner

Michael Krufky mkrufky at linuxtv.org
Mon Nov 26 06:47:38 CET 2007

kevin liu wrote:
> Yeah, I did this part of code already.
>     I design mt2131_set_tv_freq(struct i2c_client *cli, unsigned int
> freq) function and I compile this part of code into tuner.ko just like
> mt20xx code has done,
> ++++++++++++++++++++++++++++++++++++++++++++++++
> static void  mt2131_set_tv_freq(struct i2c_client *client, unsigned
> int freqency)

If this is your function prototype, then you must be using much older
v4l-dvb code.  You'll have to use the most recent mercurial tip in order
to use the new hybrid features after the recent tuner refactoring.

[code snipped]
> ++++++++++++++++++++++++++++++++++++++++++++++
>     For mt2131, I use the same init parameters as in ATSC, and the
> same algorithm for frequency parameters setting.
>     I can see the function correctly called when VIDIOC_S_FREQUENCY.
>     But my tv card's demod just can't get a valid NTSC IF signal.
>     So I suspect if mt2131 has different init params or different freq
> set algorithm for NTSC.
Looks like you just copied the atsc code.  I think you'll probably need
to use slightly different settings in order to use NTSC instead of ATSC...

Also, you probably have to handle a tda988x IF demod.

Try using the latest mercurial tip and add analog support for mt2131
that way -- should be easier.

Good Luck,

> On Nov 26, 2007 1:11 PM, Michael Krufky <mkrufky at linuxtv.org> wrote:
>> kevin liu wrote:
>>> Dear:
>>>     In Linux DVB framework, mt2131 works for atsc tv mode.
>>>     But the problem is that can I use the same module when I want to see any
>>> NTSC tv program?
>> mt2131 currently does not support analog television.  All we need is to fill .set_analog_params, and call it from tuner-core.c, and then it can work.
>> -Mike Krufky

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