KP_SEL
ret = adp5588_write(client, KP_GPIO1, KP_SEL(kpad->rows));
ret = adp5588_write(client, KP_GPIO2, KP_SEL(kpad->cols) & 0xFF);
ret = adp5588_write(client, KP_GPIO3, KP_SEL(kpad->cols) >> 8);