lp3971_reg_read
val = lp3971_reg_read(lp3971, LP3971_LDO_ENABLE_REG);
reg = lp3971_reg_read(lp3971, LP3971_LDO_VOL_CONTR_REG(ldo));
val = lp3971_reg_read(lp3971, LP3971_BUCK_VOL_ENABLE_REG);
reg = lp3971_reg_read(lp3971, LP3971_BUCK_TARGET_VOL1_REG(buck));
static u8 lp3971_reg_read(struct lp3971 *lp3971, u8 reg);