From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>,
Hartmut Knaack <knaack.h@gmx.de>,
Lars-Peter Clausen <lars@metafoo.de>,
Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
Gregory CLEMENT <gregory.clement@bootlin.com>,
linux-iio <linux-iio@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/2] iio: adc: ti-ads8344: properly byte swap value
Date: Fri, 17 Apr 2020 13:13:02 +0200 [thread overview]
Message-ID: <20200417111302.GZ34509@piout.net> (raw)
In-Reply-To: <CAHp75VeUdj4kkGMaapZu2i96faxmdnhC4a4GF1UoGfSKAVtg6g@mail.gmail.com>
On 17/04/2020 13:47:33+0300, Andy Shevchenko wrote:
> On Fri, Apr 17, 2020 at 1:44 PM Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
> >
> > On Thu, Apr 16, 2020 at 11:55 PM Alexandre Belloni
> > <alexandre.belloni@bootlin.com> wrote:
> > >
> > > The first received byte is the MSB, followed by the LSB so the value needs
> > > to be byte swapped.
> > >
> > > Also, the ADC actually has a delay of one clock on the SPI bus. Read three
> > > bytes to get the last bit.
> > >
> >
> > Can you show example of what is read and what is expected to be a correct value?
> > Because it seems I have been reported with similar issue on other TI
> > ADC chip [1]. Perhaps we have to fix all of them?
> >
> > [1]: https://github.com/edison-fw/meta-intel-edison/issues/108
>
> Also, forgot to mention that TI ADC are 16 bit word, so, we need to
> read two u16 rather then bytes.
>
> Some configuration won't allow to do byte reads.
>
Both ADC families are not related, I don't think this is your issue. The
ADS8344 was from Burr-Brown.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
next prev parent reply other threads:[~2020-04-17 11:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-16 20:54 [PATCH v2 0/2] iio: adc: ti-ads8344: driver improvements Alexandre Belloni
2020-04-16 20:54 ` [PATCH v2 1/2] iio: adc: ti-ads8344: properly byte swap value Alexandre Belloni
2020-04-17 10:44 ` Andy Shevchenko
2020-04-17 10:47 ` Andy Shevchenko
2020-04-17 11:13 ` Alexandre Belloni [this message]
2020-04-17 13:43 ` Andy Shevchenko
2020-04-17 13:45 ` Andy Shevchenko
2020-04-17 14:23 ` Alexandre Belloni
2020-04-18 15:06 ` Jonathan Cameron
2020-04-16 20:54 ` [PATCH v2 2/2] iio: adc: ti-ads8344: optimize consumption Alexandre Belloni
2020-04-18 15:13 ` Jonathan Cameron
2020-04-30 20:17 ` Alexandre Belloni
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