[linux-dvb] Thoughts about supporting more complex tuners

Manu Abraham abraham.manu at gmail.com
Fri Apr 14 15:28:03 CEST 2006


Andrew de Quincey wrote:
> On Friday 14 April 2006 13:57, Andrew de Quincey wrote:
>   
>> OK, after consulting with Manu a bit, my original idea isn't going to work
>> well. Here is an updated patch.
>>
>> The initialisation sequence would now be:
>> struct dvb_frontend *fe = stv0299_attach();
>> stb6100_attach(fe);
>>
>> The stb6100 attaches itself to the stv0299 using the (*attach_tuner)()
>> callback.
>>
>> After that, the stv0299 is then responsible for controlling the PLL - so
>> this really just becomes a standardised/expanded way of how we do it
>> already.
>>
>> Main reason being - many of the enhanced demod tuning algorithms will need
>> to control the tuner directly - my idea of the frontend loop doing this
>> just isn't flexible enough.
>>     
>
> Yet another change. This new patch exposes the tuner function pointers to the 
> world (as a part of dvb_frontend_ops) so that the card driver can override 
> them.. 
>
> For example many of the tda10045 cards have an extra chip on them which needs 
> to be set correctly for the bandwidth - this would be done by the card driver 
> overriding the tuner's set_bandwidth() function pointer with its own 
> implementation.
>   
>   

Looks nice, switching over ..

Thanks,
Manu




> ------------------------------------------------------------------------
>
> diff -r 2b05b5271ae1 linux/drivers/media/dvb/dvb-core/dvb_frontend.h
> --- a/linux/drivers/media/dvb/dvb-core/dvb_frontend.h	Thu Apr 13 12:29:04 2006 -0400
> +++ b/linux/drivers/media/dvb/dvb-core/dvb_frontend.h	Fri Apr 14 14:07:09 2006 +0100
> @@ -49,6 +49,21 @@ struct dvb_frontend_tune_settings {
>  
>  struct dvb_frontend;
>  
> +struct dvb_tuner_ops {
> +	int (*release)(struct dvb_frontend *fe, void*tuner_priv);
> +
> +	int (*init)(struct dvb_frontend *fe, void *tuner_priv);
> +	int (*sleep)(struct dvb_frontend *fe, void *tuner_priv);
> +
> +	int (*set_frequency)(struct dvb_frontend *fe, void *tuner_priv, u32 frequency);
> +	int (*get_frequency)(struct dvb_frontend *fe, void *tuner_priv, u32 *frequency);
> +	int (*set_bandwidth)(struct dvb_frontend *fe, void *tuner_priv, u32 bandwidth);
> +	int (*get_bandwidth)(struct dvb_frontend *fe, void *tuner_priv, u32 *bandwidth);
> +
> +#define TUNER_STATUS_LOCKED 1
> +        int (*get_status)(struct dvb_frontend *fe, void *tuner_priv, u32 *status);
> +};
> +
>  struct dvb_frontend_ops {
>  
>  	struct dvb_frontend_info info;
> @@ -86,7 +101,12 @@ struct dvb_frontend_ops {
>  	int (*enable_high_lnb_voltage)(struct dvb_frontend* fe, long arg);
>  	int (*dishnetwork_send_legacy_command)(struct dvb_frontend* fe, unsigned long cmd);
>  	int (*i2c_gate_ctrl)(struct dvb_frontend* fe, int enable);
> +
> +	int (*attach_tuner)(struct dvb_frontend *fe, void *tuner_priv);
> +
> +	struct dvb_tuner_ops tuner_ops;
>  };
> +
>  
>  #define MAX_EVENT 8
>  
>   




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