Hi Vignesh, did you recognize my last email ? whats your opinion around that =
best regards, Hannes ----- Forwarded by Hannes Petermaier/Eggelsberg/AT/B&R on 14.04.2015 13:14 ----- Hannes Petermaier/Eggelsberg/AT/B&R schrieb am 07.04.2015 14:30:19: > From: Hannes Petermaier/Eggelsberg/AT/B&R > To: [email protected] > Cc: [email protected] > Date: 07.04.2015 14:30 > Subject: WG: Fwd: [PATCH 0/2] iio: ti_am335x_adc: Add optional DT properties for tscadc > > Hi Vignesh, > > would it be possible to add some more channel-specific settings ? > > It would be nice to have allmost full control to the STEPCONFIGx register. > > At least we need to write the bits > > SEL_RFM_SWC_1_0 > SEL_INM_SWC_3_0 > SEL_RFP_SWC_2_0 > > In the current mainline version only (SEL_INP_SWC_3_0) is written. > So for the other bits "0" is value is used, for my point of view this is not correct. > > For example if we want to read a value from AIN5 the negative pin from adc is > muxed allways to AIN0. > In fact i can readout heavy jitter even if AIN5 is connected to ground - after > setting up negative adc pin within code (to use REFN) the readout value is 0 > as expected without nameable jitter. > If i short AIN0 also to ground, jitter is also eliminated. > > Maybe this is also some fault of TI SoC ... in normal case somebody could > expect, that negative adc pin is equal even the Diff_CNTRL bit isn't set - but > in practice it isn't. > > Also actually it isn't possible to make some accurate measurement due to the > fact that allways VDDA_ADC is used as positive reference. > > So it would be nice to have control around this bits. > Whats your opinion around that? > > best regards, > Hannes > ----- Forwarded by Hannes Petermaier/Eggelsberg/AT/B&R on 07.04.2015 14:17 ----- > > From: Johannes Pointner <[email protected]> > To: [email protected] > Date: 07.04.2015 13:58 > Subject: Fwd: [PATCH 0/2] iio: ti_am335x_adc: Add optional DT properties for tscadc > > ---------- Forwarded message ---------- > From: Vignesh R <[email protected]> > Date: 2015-03-31 13:12 GMT+02:00 > Subject: [PATCH 0/2] iio: ti_am335x_adc: Add optional DT properties for tscadc > To: Rob Herring <[email protected]>, Pawel Moll <[email protected]>, > Mark Rutland <[email protected]>, Ian Campbell > <[email protected]>, Kumar Gala <[email protected]>, > Jonathan Cameron <[email protected]> > Cc: Hartmut Knaack <[email protected]>, Lars-Peter Clausen > <[email protected]>, Peter Meerwald <[email protected]>, Dmitry Torokhov > <[email protected]>, Karol Wrona <[email protected]>, Jan > Kardell <[email protected]>, [email protected], > [email protected], [email protected], > [email protected], Vignesh R <[email protected]> > > > > Hi, > > This patch adds optional DT properties for tscadc to set open delay, > sample delay and number of averages per sample for each adc channel. > Open delay, sample delay and averaging are some of the parameters that > affect the sampling rate and accuracy of the tscadc. Decreasing delays > and averaging helps to achieve higher sampling rates, while increasing > this parameters provides greater accuracy. Hence, this patch provides DT > properties to set the initial values for delays and number of averages > per sample. User space control via sysfs can be added later. > > > Vignesh R (2): > iio: adc: ti_am335x_adc: refactor DT parsing into a function > iio: adc: ti_am335x_adc: make sample delay, open delay, averaging DT > parameters > > .../bindings/input/touchscreen/ti-tsc-adc.txt | 24 +++++++ > drivers/iio/adc/ti_am335x_adc.c | 83 +++++++++++++++++----- > 2 files changed, 91 insertions(+), 16 deletions(-) > > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- 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/
