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SubjectFwd: Fwd: [PATCH 0/2] iio: ti_am335x_adc: Add optional DT properties for tscadc
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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: vigneshr@ti.com
> Cc: linux-iio@vger.kernel.org
> 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 <johannes.pointner@gmail.com>
> To: hannes.petermaier@br-automation.com
> 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 <vigneshr@ti.com>
> 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 <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
> Mark Rutland <mark.rutland@arm.com>, Ian Campbell
> <ijc+devicetree@hellion.org.uk>, Kumar Gala <galak@codeaurora.org>,
> Jonathan Cameron <jic23@kernel.org>
> Cc: Hartmut Knaack <knaack.h@gmx.de>, Lars-Peter Clausen
> <lars@metafoo.de>, Peter Meerwald <pmeerw@pmeerw.net>, Dmitry Torokhov
> <dmitry.torokhov@gmail.com>, Karol Wrona <k.wrona@samsung.com>, Jan
> Kardell <jan.kardell@telliq.com>, devicetree@vger.kernel.org,
> linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org,
> fcooper@ti.com, Vignesh R <vigneshr@ti.com>
>
>
>
> 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
>
> --
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