From: Lars-Peter Clausen <lars@metafoo.de>
To: Jonathan Cameron <jic23@kernel.org>,
abhijit <abhijitnaik27@gmail.com>,
linux-iio@vger.kernel.org,
Patrick Vasseur <patrick.vasseur@c-s.fr>,
Michael Hennerich <hennerich@blackfin.uclinux.org>
Subject: Re: AD7923 sequencer functionality implementation in Kernel
Date: Mon, 09 Mar 2015 14:34:05 +0100 [thread overview]
Message-ID: <54FDA14D.3010803@metafoo.de> (raw)
In-Reply-To: <54FD9CD9.3080306@kernel.org>
On 03/09/2015 02:15 PM, Jonathan Cameron wrote:
> On 09/03/15 05:28, abhijit wrote:
>> Hi All,
>>
>> We are using AD7923 driver as reference for one of our customer's ADC IP
>>
>> The ADC that we are using, has sequencer functionality. In current state of AD7923 driver, there is no support for sequencer functionality.
>>
>> Can you please let me know whether the IIO driver team is coming up with design for sequencer functionality of the device.
> Cc'd Lars, Michael and Patrick. Looks like a fairly standard sequencer.
> Just a question of whether anyone has already looked at it.
I've been tormenting my head now for a while how to properly model
sequencers in IIO, but haven't come to a conclusion yet.
The problem is you have one physical channel but a configurable amount of
logical channels. The ADC will cycle through the selected channels one after
another.
IIO on the other hand expects that all channels that are selected are
actually converted at the same time. E.g. you have to supply all the
selected channels at the same time to iio_buffer_push_data() and also
metadata, like the timestamps, is expected to be supplied only once for
every set of samples and not for every individual logical channel.
Furthermore things like the output data rate of each channel depend on the
number of selected channels. So if you configure the sample rate and then
change the number of selected channels you potentially end up with a
different sample rate than initially selected.
- Lars
next prev parent reply other threads:[~2015-03-09 13:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-09 5:28 AD7923 sequencer functionality implementation in Kernel abhijit
2015-03-09 13:15 ` Jonathan Cameron
2015-03-09 13:34 ` Lars-Peter Clausen [this message]
2015-03-09 13:49 ` IIO Channel Sequencer Handling. was " Jonathan Cameron
2015-03-10 13:29 ` Lars-Peter Clausen
2015-03-21 11:55 ` Jonathan Cameron
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=54FDA14D.3010803@metafoo.de \
--to=lars@metafoo.de \
--cc=abhijitnaik27@gmail.com \
--cc=hennerich@blackfin.uclinux.org \
--cc=jic23@kernel.org \
--cc=linux-iio@vger.kernel.org \
--cc=patrick.vasseur@c-s.fr \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).