From: Michael Welling <mwelling@ieee.org>
To: Daniel Baluta <daniel.baluta@intel.com>
Cc: jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de,
pmeerw@pmeerw.net, linux-kernel@vger.kernel.org,
linux-iio@vger.kernel.org, lucas.demarchi@intel.com,
linux@roeck-us.net, eibach@gdsys.de
Subject: Re: [PATCH v4] iio: adc: Add TI ADS1015 ADC driver support
Date: Mon, 29 Feb 2016 18:50:32 -0600 [thread overview]
Message-ID: <20160301005032.GA15476@deathstar> (raw)
In-Reply-To: <1454678238-16313-1-git-send-email-daniel.baluta@intel.com>
On Fri, Feb 05, 2016 at 03:17:18PM +0200, Daniel Baluta wrote:
> The driver has sysfs readings with runtime PM support for power saving.
> It also offers buffer support that can be used together with IIO software
> triggers.
>
Daniel,
So I noticed something yesterday while testing new boards.
The channels are occassionally swapping when accessing data from multiple channels.
I wrote a simple bash script to demonstrate.
root@dragonboard-410c:~# cat test-analog.sh
while [ 1 ]; do
voltage0=`cat /sys/bus/iio/devices/iio\:device0/in_voltage0_raw`
voltage1=`cat /sys/bus/iio/devices/iio\:device0/in_voltage1_raw`
voltage2=`cat /sys/bus/iio/devices/iio\:device0/in_voltage2_raw`
voltage3=`cat /sys/bus/iio/devices/iio\:device0/in_voltage3_raw`
echo ain0 = $voltage0 ain1 = $voltage1 ain2 = $voltage2 ain3 = $voltage3
done
root@dragonboard-410c:~# ./test-analog.sh
ain0 = 266 ain1 = 291 ain2 = 268 ain3 = 291
ain0 = 287 ain1 = 294 ain2 = 289 ain3 = 292
ain0 = 284 ain1 = 294 ain2 = 286 ain3 = 0
ain0 = 285 ain1 = 288 ain2 = 287 ain3 = 0
ain0 = 287 ain1 = 286 ain2 = 287 ain3 = 0
ain0 = 285 ain1 = 287 ain2 = 293 ain3 = 0
ain0 = 0 ain1 = 289 ain2 = 293 ain3 = 0
ain0 = 0 ain1 = 289 ain2 = 290 ain3 = 291
ain0 = 287 ain1 = 289 ain2 = 289 ain3 = 0
ain0 = 0 ain1 = 285 ain2 = 288 ain3 = 0
ain0 = 285 ain1 = 286 ain2 = 288 ain3 = 0
ain0 = 286 ain1 = 288 ain2 = 285 ain3 = 0
ain0 = 287 ain1 = 293 ain2 = 289 ain3 = 292
ain0 = 288 ain1 = 292 ain2 = 287 ain3 = 293
ain0 = 286 ain1 = 287 ain2 = 289 ain3 = 0
ain0 = 283 ain1 = 289 ain2 = 289 ain3 = 0
ain0 = 0 ain1 = 287 ain2 = 287 ain3 = 0
ain0 = 0 ain1 = 286 ain2 = 288 ain3 = 0
ain0 = 286 ain1 = 288 ain2 = 289 ain3 = 0
ain0 = 287 ain1 = 286 ain2 = 290 ain3 = 0
ain0 = 289 ain1 = 291 ain2 = 287 ain3 = 0
ain0 = 284 ain1 = 286 ain2 = 292 ain3 = 0
ain0 = 286 ain1 = 291 ain2 = 289 ain3 = 292
ain0 = 284 ain1 = 292 ain2 = 291 ain3 = 291
ain0 = 285 ain1 = 287 ain2 = 287 ain3 = 0
ain0 = 0 ain1 = 289 ain2 = 291 ain3 = 0
ain0 = 0 ain1 = 288 ain2 = 291 ain3 = 0
ain0 = 0 ain1 = 286 ain2 = 288 ain3 = 0
ain0 = 286 ain1 = 287 ain2 = 290 ain3 = 0
ain0 = 286 ain1 = 286 ain2 = 288 ain3 = 0
ain0 = 286 ain1 = 286 ain2 = 287 ain3 = 0
ain0 = 285 ain1 = 289 ain2 = 288 ain3 = 288
ain0 = 289 ain1 = 292 ain2 = 289 ain3 = 293
ain0 = 287 ain1 = 292 ain2 = 290 ain3 = 0
ain0 = 286 ain1 = 286 ain2 = 291 ain3 = 0
ain0 = 0 ain1 = 287 ain2 = 290 ain3 = 0
ain0 = 0 ain1 = 286 ain2 = 289 ain3 = 0
ain0 = 284 ain1 = 285 ain2 = 292 ain3 = 0
ain0 = 285 ain1 = 289 ain2 = 289 ain3 = 0
ain0 = 287 ain1 = 287 ain2 = 287 ain3 = 0
ain0 = 287 ain1 = 291 ain2 = 287 ain3 = 291
ain0 = 288 ain1 = 291 ain2 = 290 ain3 = 293
ain0 = 285 ain1 = 290 ain2 = 287 ain3 = 292
ain0 = 285 ain1 = 289 ain2 = 289 ain3 = 292
ain0 = 286 ain1 = 289 ain2 = 288 ain3 = 0
ain0 = 0 ain1 = 286 ain2 = 291 ain3 = 0
ain0 = 0 ain1 = 287 ain2 = 291 ain3 = 0
ain0 = 287 ain1 = 286 ain2 = 291 ain3 = 0
ain0 = 288 ain1 = 286 ain2 = 289 ain3 = 0
ain0 = 284 ain1 = 289 ain2 = 288 ain3 = 0
ain0 = 287 ain1 = 290 ain2 = 287 ain3 = 292
ain0 = 285 ain1 = 292 ain2 = 289 ain3 = 292
ain0 = 289 ain1 = 292 ain2 = 290 ain3 = 0
.
.
The in_voltage3_raw channel is connected to GND the rest are left floating.
This does not happen if only one channels is accessed at a time.
I have not yet found the solution. Please left me know if this can be
duplicated on your end.
Regards,
Michael
next prev parent reply other threads:[~2016-03-01 0:50 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-05 13:17 [PATCH v4] iio: adc: Add TI ADS1015 ADC driver support Daniel Baluta
2016-02-05 17:25 ` Michael Welling
2016-02-05 19:32 ` Daniel Baluta
2016-02-05 19:50 ` Michael Welling
2016-02-06 0:32 ` Michael Welling
2016-02-08 10:25 ` Wolfram Sang
2016-02-08 14:44 ` Daniel Baluta
2016-02-08 15:03 ` Daniel Baluta
2016-02-08 16:37 ` Michael Welling
2016-02-08 16:36 ` Michael Welling
2016-02-08 19:11 ` Sricharan
2016-02-08 19:16 ` Michael Welling
2016-02-08 20:00 ` Wolfram Sang
2016-02-08 20:06 ` Michael Welling
2016-02-10 12:22 ` Sricharan
2016-02-10 12:56 ` Daniel Baluta
2016-02-10 15:09 ` Sricharan
2016-02-10 16:36 ` Michael Welling
2016-02-17 23:53 ` Michael Welling
2016-02-18 8:45 ` Sricharan
2016-02-05 21:02 ` Lucas De Marchi
2016-02-05 21:44 ` Daniel Baluta
2016-02-06 10:52 ` Jonathan Cameron
2016-02-06 11:05 ` Jonathan Cameron
2016-02-06 11:07 ` Jonathan Cameron
2016-03-01 0:50 ` Michael Welling [this message]
2016-03-01 1:09 ` Lucas De Marchi
2016-03-01 1:16 ` Michael Welling
2016-03-01 1:33 ` Michael Welling
2016-03-01 2:42 ` Michael Welling
2016-03-01 8:35 ` jic23
2016-03-01 16:02 ` Michael Welling
2016-03-01 17:24 ` Jonathan Cameron
2016-03-01 11:28 ` Daniel Baluta
2016-03-01 15:57 ` Michael Welling
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