lp3943_write_byte
EXPORT_SYMBOL_GPL(lp3943_write_byte);
err = lp3943_write_byte(lp3943, reg_prescale, val);
return lp3943_write_byte(lp3943, reg_duty, val);
int lp3943_write_byte(struct lp3943 *lp3943, u8 reg, u8 data);