input_signal
if (brightness < caps->luminance_data[0].input_signal) {
caps->luminance_data[0].input_signal);
u8 signal = caps->luminance_data[mid].input_signal;
lower_signal = caps->luminance_data[right].input_signal;
upper_signal = caps->luminance_data[left].input_signal;
u8 input_signal;
u8 input_signal; /* input signal in range 0-255 */
void input_signal(int);
act.sa_handler = input_signal;