From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Ralf Schlatterbeck <rsc@runtux.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
Linus Walleij <linus.walleij@linaro.org>,
Miguel Ojeda <ojeda@kernel.org>, Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Conor Dooley <conor+dt@kernel.org>,
Robin van der Gracht <robin@protonic.nl>,
Paul Burton <paulburton@kernel.org>,
linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: Re: [PATCH 1/3] dt-bindings: auxdisplay: hit, hd44780: drop redundant GPIO node
Date: Mon, 12 Feb 2024 14:38:27 +0100 [thread overview]
Message-ID: <e2a5b005-7916-4296-b072-c24efd4b3357@linaro.org> (raw)
In-Reply-To: <20240212115837.efz73yxinkysdmgh@runtux.com>
On 12/02/2024 12:58, Ralf Schlatterbeck wrote:
> On Mon, Feb 12, 2024 at 12:25:48PM +0100, Krzysztof Kozlowski wrote:
>>
>> Hm, I don't understand how exactly it helps. The GPIO expander has its
>> own example and as you pointed below, this is basically the same code,
>> except rw and backlight GPIOs.
>
> The hd44780 is a display that is very often used.
> By people (like me some time ago) not familiar with the nice io expander
> implementation in Linux. The consequence of that is that you'll find
> several out-of-tree implementations for this display with i2c out in the
> wild. So my thought of documenting this (again) at that location is to
> make it easier for people with a hd44780 with the standard i2c interface
> to see how it is done in Linux.
GPIO expanders and their usage is nothing specific to this device -
other devices also might benefit of them. Or the SoCs which have enough
of GPIOs... I really do not understand why do we need expander here and
how does it help
Anyway, binding examples should not be collection of unrelated
solutions, because then we should accept for each device schema several
other variations and combinations.
Best regards,
Krzysztof
next prev parent reply other threads:[~2024-02-12 13:38 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-12 8:34 [PATCH 1/3] dt-bindings: auxdisplay: hit,hd44780: " Krzysztof Kozlowski
2024-02-12 8:34 ` [PATCH 2/3] dt-bindings: auxdisplay: adjust example indentation and use generic node names Krzysztof Kozlowski
2024-02-12 12:14 ` Andy Shevchenko
2024-02-12 8:34 ` [PATCH 3/3] dt-bindings: auxdisplay: hit,hd44780: use defines for GPIO flags Krzysztof Kozlowski
2024-02-12 12:15 ` Andy Shevchenko
2024-02-12 8:41 ` [PATCH 1/3] dt-bindings: auxdisplay: hit,hd44780: drop redundant GPIO node Geert Uytterhoeven
2024-02-12 11:25 ` Krzysztof Kozlowski
2024-02-12 11:58 ` [PATCH 1/3] dt-bindings: auxdisplay: hit, hd44780: " Ralf Schlatterbeck
2024-02-12 13:38 ` Krzysztof Kozlowski [this message]
2024-02-12 13:43 ` Andy Shevchenko
2024-02-12 13:59 ` Krzysztof Kozlowski
2024-02-12 14:04 ` Andy Shevchenko
2024-02-13 16:19 ` Rob Herring
2024-02-13 16:43 ` Andy Shevchenko
2024-02-14 9:57 ` Krzysztof Kozlowski
2024-02-12 14:39 ` Ralf Schlatterbeck
2024-02-12 15:24 ` Geert Uytterhoeven
2024-02-13 9:07 ` Ralf Schlatterbeck
2024-02-12 13:39 ` [PATCH 1/3] dt-bindings: auxdisplay: hit,hd44780: " Andy Shevchenko
2024-02-12 13:56 ` Krzysztof Kozlowski
2024-02-12 14:09 ` Andy Shevchenko
2024-02-12 14:20 ` Krzysztof Kozlowski
2024-02-12 14:31 ` Andy Shevchenko
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=e2a5b005-7916-4296-b072-c24efd4b3357@linaro.org \
--to=krzysztof.kozlowski@linaro.org \
--cc=andriy.shevchenko@linux.intel.com \
--cc=conor+dt@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=geert@linux-m68k.org \
--cc=krzysztof.kozlowski+dt@linaro.org \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ojeda@kernel.org \
--cc=paulburton@kernel.org \
--cc=robh+dt@kernel.org \
--cc=robin@protonic.nl \
--cc=rsc@runtux.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
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
all inboxes | Powered by JetHome®