LM87_REG_VID_FAN_DIV
i = lm87_read_value(client, LM87_REG_VID_FAN_DIV);
reg = lm87_read_value(client, LM87_REG_VID_FAN_DIV);
lm87_write_value(client, LM87_REG_VID_FAN_DIV, reg);