On Wed, 2014-11-05 at 13:09 +0000, Jonathan Cameron wrote: > On 03/11/14 15:24, Ivan T. Ivanov wrote: > > From: Stanimir Varbanov <svarbanov@xxxxxxxxxx> > > > > The voltage ADC is peripheral of Qualcomm SPMI PMIC chips. It has > > 15 bits resolution and register space inside PMIC accessible across > > SPMI bus. > > > > The vadc driver registers itself through IIO interface. > > > > Signed-off-by: Stanimir Varbanov <svarbanov@xxxxxxxxxx> > > Signed-off-by: Ivan T. Ivanov <iivanov@xxxxxxxxxx> > Hi Ivan, > > Couple of utterly tiny bits inline. The biggest one is that > you store some info about the calibration that you never actually > use... Left over from some debugging perhaps? > > Jonathan <snip> > > + > > +/* > > + * VADC_CALIB_ABSOLUTE: uses the 625mV and 1.25V as reference channels. > > + * VADC_CALIB_RATIOMETRIC: uses the reference voltage (1.8V) and GND for > > + * calibration. > > + */ > > +enum vadc_calibration { > > + VADC_CALIB_ABSOLUTE = 0, > > + VADC_CALIB_RATIOMETRIC > > +}; > > + > > +/** > > + * struct vadc_linear_graph - Represent ADC characteristics. > > + * @dy: numerator slope to calculate the gain. > As dy is always equal to vref-gnd you could drop it and use those > directly... > > Conversly you store vref or grnd and never use them... I am not sure I am following you. Please take a look in vadc_measure_ref_points() and vadc_calibrate(). > > > + * @dx: denominator slope to calculate the gain. > > + * @vref: A/D word of the voltage reference used for the channel. > > + * @gnd: A/D word of the ground reference used for the channel. > > + * > > + * Each ADC device has different offset and gain parameters which are > > + * computed to calibrate the device. > > + */ > > +struct vadc_linear_graph { > > + s32 dy; > > + s32 dx; > > + s32 vref; > > + s32 gnd; > > +}; > > + > > Will address blank line comment. Regards, Ivan -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html