linux/include/media/tuner-types.h

57 lines
1.4 KiB
C

/*
* descriptions for simple tuners.
*/
#ifndef __TUNER_TYPES_H__
#define __TUNER_TYPES_H__
enum param_type {
TUNER_PARAM_TYPE_RADIO, \
TUNER_PARAM_TYPE_PAL, \
TUNER_PARAM_TYPE_SECAM, \
TUNER_PARAM_TYPE_NTSC
};
struct tuner_range {
unsigned short limit;
unsigned char config;
unsigned char cb;
};
struct tuner_params {
enum param_type type;
/* Many Philips based tuners have a comment like this in their
* datasheet:
*
* For channel selection involving band switching, and to ensure
* smooth tuning to the desired channel without causing
* unnecessary charge pump action, it is recommended to consider
* the difference between wanted channel frequency and the
* current channel frequency. Unnecessary charge pump action
* will result in very low tuning voltage which may drive the
* oscillator to extreme conditions.
*
* Set cb_first_if_lower_freq to 1, if this check is
* required for this tuner.
*
* I tested this for PAL by first setting the TV frequency to
* 203 MHz and then switching to 96.6 MHz FM radio. The result was
* static unless the control byte was sent first.
*/
unsigned int cb_first_if_lower_freq:1;
unsigned int count;
struct tuner_range *ranges;
};
struct tunertype {
char *name;
unsigned int count;
struct tuner_params *params;
};
extern struct tunertype tuners[];
extern unsigned const int tuner_count;
#endif