From: Shawn Guo <shawnguo@kernel.org>
To: Fabio Estevam <festevam@gmail.com>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>,
Markus Niebel <Markus.Niebel@tq-group.com>
Subject: Re: [PATCH 1/4] ARM: dts: imx6dl-alti6p: Fix the SPI chipselect polarity
Date: Wed, 22 Sep 2021 09:23:34 +0800 [thread overview]
Message-ID: <20210922012333.GB10217@dragon> (raw)
In-Reply-To: <CAOMZO5Ba=M9vRZHk+tKjBCUa+mAULhiGG6Y+uefQE3RYGAnF3w@mail.gmail.com>
On Sat, Aug 14, 2021 at 10:27:13AM -0300, Fabio Estevam wrote:
> Hi Shawn,
>
> On Sat, Jul 17, 2021 at 1:57 AM Oleksij Rempel <o.rempel@pengutronix.de> wrote:
> >
> > On Fri, Jul 16, 2021 at 10:36:56AM -0300, Fabio Estevam wrote:
> > > The conversion of the spi-imx driver to use GPIO descriptors
> > > in commit 8cdcd8aeee28 ("spi: imx/fsl-lpspi: Convert to GPIO descriptors")
> > > helped to detect the following SPI chipselect polarity mismatch on an
> > > imx6q-sabresd for example:
> > >
> > > [ 4.854337] m25p80@0 enforce active low on chipselect handle
> > >
> > > Prior to the above commit, the chipselect polarity passed via cs-gpios
> > > property was ignored and considered active-low.
> > >
> > > The reason for such mismatch is clearly explained in the comments inside
> > > drivers/gpio/gpiolib-of.c:
> > >
> > > * SPI children have active low chip selects
> > > * by default. This can be specified negatively
> > > * by just omitting "spi-cs-high" in the
> > > * device node, or actively by tagging on
> > > * GPIO_ACTIVE_LOW as flag in the device
> > > * tree. If the line is simultaneously
> > > * tagged as active low in the device tree
> > > * and has the "spi-cs-high" set, we get a
> > > * conflict and the "spi-cs-high" flag will
> > > * take precedence.
> > >
> > > To properly represent the SPI chipselect polarity, change it to active-low
> > > when the "spi-cs-high" property is absent.
> > >
> > > Signed-off-by: Fabio Estevam <festevam@gmail.com>
> >
> > Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
> > Thank you!
>
> A gentle ping on this series.
Should we have Fixes tags for the patches?
Shawn
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-09-22 1:25 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-16 13:36 [PATCH 1/4] ARM: dts: imx6dl-alti6p: Fix the SPI chipselect polarity Fabio Estevam
2021-07-16 13:36 ` [PATCH 2/4] ARM: dts: imx6qp-prtwd3: " Fabio Estevam
2021-07-17 4:58 ` Oleksij Rempel
2021-09-22 3:02 ` Shawn Guo
2021-07-16 13:36 ` [PATCH 3/4] ARM: dts: imx6qdl-tqma6: " Fabio Estevam
2021-07-16 13:36 ` [PATCH 4/4] ARM: dts: imx7d-sdb: " Fabio Estevam
2021-07-17 4:57 ` [PATCH 1/4] ARM: dts: imx6dl-alti6p: " Oleksij Rempel
2021-08-14 13:27 ` Fabio Estevam
2021-09-22 1:23 ` Shawn Guo [this message]
2021-09-22 1:28 ` Fabio Estevam
2021-09-22 2:03 ` Shawn Guo
2021-09-22 2:04 ` Fabio Estevam
2021-09-22 3:04 ` Shawn Guo
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=20210922012333.GB10217@dragon \
--to=shawnguo@kernel.org \
--cc=Markus.Niebel@tq-group.com \
--cc=festevam@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=o.rempel@pengutronix.de \
/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).