On 05/11/14 15:01, Ivan T. Ivanov wrote: > > 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 <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(). >> 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. Probably best as otherwise some compiler in a clever mood will give a warning and I'll get an irritating patch to remove it! J > > Regards, > Ivan > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html