Using polled input devices

Polled input devices are special input devices that rely on polling to sense device state changes; the generic input device type relies on IRQ to sense changes and send events to the input core.

A polled input device is described in the kernel as an instance of struct input_polled_dev structure, which is a wrapper around the generic struct input_dev structure. The following is its declaration:

struct input_polled_dev {
    void *private;
    void (*open)(struct input_polled_dev *dev);
    void (*close)(struct input_polled_dev *dev);
    void (*poll)(struct input_polled_dev *dev);
    unsigned int poll_interval; /* msec */
    unsigned int poll_interval_max; /* msec */
    unsigned int poll_interval_min; /* msec */
 
    struct input_dev *input;
    bool devres_managed;
};

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