Linux-OMAP Archive on lore.kernel.org
 help / color / Atom feed
From: Drew Fustini <drew@beagleboard.org>
To: Trent Piepho <tpiepho@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>,
	Rob Herring <robh+dt@kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Jason Kridner <jkridner@beagleboard.org>,
	Robert Nelson <robertcnelson@gmail.com>,
	linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org,
	linux-gpio <linux-gpio@vger.kernel.org>
Subject: Re: [PATCH] ARM: dts: document pinctrl-single,pins when #pinctrl-cells = 2
Date: Thu, 17 Sep 2020 11:20:04 +0200
Message-ID: <20200917092004.GA2468349@x1> (raw)
In-Reply-To: <CA+7tXii8rwBexgAHeqYsvBywhWLmk-Hf5_VWUU5bQkBREeFcSA@mail.gmail.com>

On Thu, Sep 17, 2020 at 02:03:46AM -0700, Trent Piepho wrote:
> On Mon, Sep 14, 2020 at 3:44 AM Drew Fustini <drew@beagleboard.org> wrote:
> >
> > +
> > +When #pinctrl-cells = 2, then setting a pin for a device could be done with:
> > +
> > +       pinctrl-single,pins = <0xdc 0x30 0x07>;
> > +
> > +Where 0x30 is the pin configuration value and 0x07 is the pin mux mode value.
> > +See the device example and static board pins example below for more information.
> 
> Pin configuration and mux mode don't mean anything in pinctrl-single.
> On another machine, mux mode might not be programmed this way or even
> exist.  Or the location of bits would probably be different, and this
> would seem to imply the 0x07 would get shifted to the correct location
> for where the pin mux setting was on that machine's pinctrl registers.
> 
> It seems like it would be better to explain the values are ORed together.

I descirbed it as seoerate values as I did not want to prescribe what
the pcs driver would do with those values.  But, yes, it is a just an OR
operation, so I could change the language to reflect tat.

> What is the purpose of this change anyway?  It seems like in the end
> it just does what it did before.  The data is now split into two cells
> in the device tree, but why?

These changes were a result of desire to seperate pinconf and pinmux.
Tony raised the idea in a thread at the end of May [1].

Tony wrote:
> Only slightly related, but we should really eventually move omaps to use
> #pinctrl-cells = <2> (or 3) instead of 1, and pass the pinconf seprately
> from the mux mode. We already treat them separately with the new
> AM33XX_PADCONF macro, so we'd only have to change one SoC at a time to
> use updated #pinctrl-cells. But I think pinctrl-single might need some
> changes before we can do that.


thanks,
drew

[1] https://lore.kernel.org/linux-omap/20200527165122.GL37466@atomide.com/

  reply index

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-14 10:43 Drew Fustini
2020-09-17  9:03 ` Trent Piepho
2020-09-17  9:20   ` Drew Fustini [this message]
2020-09-17 10:00     ` Trent Piepho
2020-09-17 10:39       ` Drew Fustini
2020-09-23  6:57         ` Tony Lindgren
2020-09-24  1:34           ` Trent Piepho
2020-09-24  5:43             ` Tony Lindgren
2020-09-24  5:49               ` Trent Piepho
2020-09-24  6:06                 ` Tony Lindgren
2020-09-24  6:31                   ` Trent Piepho
2020-09-24  7:04                     ` Tony Lindgren
2020-09-29 20:15                       ` Trent Piepho
2020-09-30  5:15                         ` Tony Lindgren
2020-09-30  8:34                           ` Trent Piepho
2020-09-30  9:15                             ` Tony Lindgren
2020-09-30  9:34                               ` Trent Piepho
2020-09-30  9:47                                 ` Tony Lindgren
2020-09-30 18:50                                   ` Trent Piepho
2020-10-01  7:00                                     ` Tony Lindgren
2020-09-23  6:59 ` Tony Lindgren

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=20200917092004.GA2468349@x1 \
    --to=drew@beagleboard.org \
    --cc=devicetree@vger.kernel.org \
    --cc=jkridner@beagleboard.org \
    --cc=linus.walleij@linaro.org \
    --cc=linux-gpio@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-omap@vger.kernel.org \
    --cc=robertcnelson@gmail.com \
    --cc=robh+dt@kernel.org \
    --cc=tony@atomide.com \
    --cc=tpiepho@gmail.com \
    /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

Linux-OMAP Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-omap/0 linux-omap/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-omap linux-omap/ https://lore.kernel.org/linux-omap \
		linux-omap@vger.kernel.org
	public-inbox-index linux-omap

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-omap


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git