On Wed, 2014-11-05 at 14:06 +0000, Jonathan Cameron wrote: > On 05/11/14 13:57, Ivan T. Ivanov wrote: > > 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 <[email protected]> > > > > > > > > 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 <[email protected]> > > > > Signed-off-by: Ivan T. Ivanov <[email protected]> > > > 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(). > Good point on grnd, but vref is set but never read anywhere that I can find.. >
Right. At this point it is not used. Driver right now provide basic per channel voltage measurements. The plan is to add temperature compensation for the measurements and additional scaling functions which are specific per channel. I could drop this field from initial driver version if you like. Regards, Ivan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
