struct tuner_setup — setup the tuner chipsets
struct tuner_setup {
unsigned short addr;
unsigned int type;
unsigned int mode_mask;
void * config;
int (* tuner_callback) (void *dev, int component, int cmd, int arg);
}; I2C address used to control the tuner device/chipset
Type of the tuner, as defined at the TUNER_* macros. Each different tuner model should have an unique identifier.
Mask with the allowed tuner modes: V4L2_TUNER_RADIO, V4L2_TUNER_ANALOG_TV and/or V4L2_TUNER_DIGITAL_TV, describing if the tuner should be used to support Radio, analog TV and/or digital TV.
Used to send tuner-specific configuration for complex tuners that require extra parameters to be set. Only a very few tuners require it and its usage on newer tuners should be avoided.
Some tuners require to call back the bridge driver, in order to do some tasks like rising a GPIO at the bridge chipset, in order to do things like resetting the device.
Older boards only had a single tuner device. Nowadays multiple tuner devices may be present on a single board. Using TUNER_SET_TYPE_ADDR to pass the tuner_setup structure it is possible to setup each tuner device in turn.
Since multiple devices may be present it is no longer sufficient to send a command to a single i2c device. Instead you should broadcast the command to all i2c devices.
By setting the mode_mask correctly you can select which commands are accepted by a specific tuner device. For example, set mode_mask to T_RADIO if the device is a radio-only tuner. That specific tuner will only accept commands when the tuner is in radio mode and ignore them when the tuner is set to TV mode.