+ /* Output voltage at 0°C = 0.755V
+ * Coefficient = 0.00247V/°C
+ * Reference voltage = 1.25V
+ *
+ * temp = ((value / 32767) * 1.25 - 0.755) / 0.00247
+ * = (value - 19791.268) / 32768 * 1.25 / 0.00247
+ * ≃ (value - 19791) * 1012 / 65536
+ */
+ ret = ((temp - 19791) * 1012L) >> 16;