From: Drew Fustini <drew@beagleboard.org>
To: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Linus Walleij <linus.walleij@linaro.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH] gpiolib: Allow name duplicates of "" and "NC"
Date: Wed, 16 Dec 2020 11:53:57 -0800 [thread overview]
Message-ID: <20201216195357.GA2583366@x1> (raw)
In-Reply-To: <20201215170308.2037624-1-bjorn.andersson@linaro.org>
On Tue, Dec 15, 2020 at 09:03:08AM -0800, Bjorn Andersson wrote:
> Not all GPIO pins are exposed to the world and this is typically
> described by not giving these lines particular names, commonly "" or
> "NC".
>
> With the recent introduction of '2cd64ae98f35 ("gpiolib: Disallow
> identical line names in the same chip")' any gpiochip with multiple such
> pins will refuse to probe.
>
> Fix this by treating "" and "NC" as "no name specified" in
> gpio_name_to_desc()
>
> Fixes: 2cd64ae98f35 ("gpiolib: Disallow identical line names in the same chip")
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>
> The introduction of 2cd64ae98f35 breaks pretty much all Qualcomm boards and
> grepping the DT tree indicates that other vendors will have the same problem.
>
> In addition to this the am335x-* boards will also needs "[NC]", "[ethernet]",
> "[emmc"], "[i2c0]", "[SYSBOOT]" and "[JTAG]" added to this list to allow
> booting v5.11 with the past and present dtb/dts files.
I am the one who added the gpio line names to the am335x dts board
files, and I am happy to change them if it will make unique line name
logic simpler.
I used the notation of "[<non-gpio-functionality>]" to make it easy for
the user to realize that the corresponding gpiolines could not be used
on these boards (BeagleBone and PocketBeagle) for actual GPIO. I used
generic names like "[ethernet]" because I didn't think it made sense
to confuse the user by using the precise name of the non-gpio function
(such as "[gmii1_rxd0]"). I could post a patch for the dts files that
restores unique names for "[ethernet]", "[emmc"], "[i2c0]",
"[SYSBOOT]" and "[JTAG]".
As for "[NC]", the BGA balls corresponding to these gpio lines are
simply not connected to any circuits on the board. I happy to change
that to whatever name people prefer for a non-connected pin ("", "NC",
etc).
Thanks,
Drew
next prev parent reply other threads:[~2020-12-16 19:54 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-15 17:03 [PATCH] gpiolib: Allow name duplicates of "" and "NC" Bjorn Andersson
2020-12-15 17:42 ` Bartosz Golaszewski
2020-12-15 17:59 ` Bjorn Andersson
2020-12-16 12:46 ` Linus Walleij
2020-12-16 18:40 ` Bjorn Andersson
2020-12-16 20:50 ` Linus Walleij
2020-12-16 19:53 ` Drew Fustini [this message]
2020-12-16 20:38 ` Bjorn Andersson
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=20201216195357.GA2583366@x1 \
--to=drew@beagleboard.org \
--cc=bgolaszewski@baylibre.com \
--cc=bjorn.andersson@linaro.org \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-gpio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/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).