From: Michael Walle <michael@walle.cc>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
Linus Walleij <linus.walleij@linaro.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>
Subject: Re: [PATCH v4 1/2] gpio: Add support for IDT 79RC3243x GPIO controller
Date: Wed, 28 Apr 2021 16:04:32 +0200 [thread overview]
Message-ID: <880011ffd80ae7d1a32e7a17d405b987@walle.cc> (raw)
In-Reply-To: <CAHp75VcXEu2YGOoL70zueEgARCe8D+Q=CFsN62-vFK5svjJAQA@mail.gmail.com>
Am 2021-04-28 15:44, schrieb Andy Shevchenko:
> On Wed, Apr 28, 2021 at 2:57 PM Michael Walle <michael@walle.cc> wrote:
>>
>> Am 2021-04-28 13:07, schrieb Andy Shevchenko:
>> > On Wed, Apr 28, 2021 at 1:51 AM Michael Walle <michael@walle.cc> wrote:
>> >> Am 2021-04-26 12:29, schrieb Andy Shevchenko:
>> >> > On Mon, Apr 26, 2021 at 12:55 PM Thomas Bogendoerfer
>> >> > <tsbogend@alpha.franken.de> wrote:
>> >> >
>> >> > 2) there is gpio-regmap generic code, that may be worth
>> >> > considering.
>> >>
>> >> This driver uses memory mapped registers. While that is
>> >> also possible with gpio-regmap, there is one drawback:
>> >> it assumes gpiochip->can_sleep = true for now, see [1].
>> >> Unfortunately, there is no easy way to ask the regmap
>> >> if its mmio/fastio.
>> >
>> > I don't see how it is an impediment.
>>
>> You'd have to use the *_cansleep() variants with the gpios,
>> which cannot be used everywhere, no?
>
> *can* sleep means that it requires a sleeping context to run, if your
> controller is fine with that, there are no worries. OTOH if you want
> to run this in an atomic context, then consumers can't do with that
> kind of controller.
Ok, then we are on the same track.
> What I meant above (and you stripped it here) is
> to add a patch that will fix that and set it based on
> gpio_regmap_config.
Yes, but ideally, it would ask the regmap. Otherwise that
information is redundant and might mismatch, i.e. gpio_regmap_config
tell can_sleep=false but the regmap is an I2C type for example. Also
if a driver wants to support both regmap types, we are no step
further.
-michael
next prev parent reply other threads:[~2021-04-28 14:04 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-26 9:54 [PATCH v4 1/2] gpio: Add support for IDT 79RC3243x GPIO controller Thomas Bogendoerfer
2021-04-26 9:54 ` [PATCH v4 2/2] dt-bindings: gpio: Add devicetree binding for IDT 79RC32434 " Thomas Bogendoerfer
2021-04-30 20:19 ` Rob Herring
2021-05-01 12:13 ` Linus Walleij
2021-05-04 13:44 ` Rob Herring
2021-05-06 11:11 ` Linus Walleij
2021-05-11 21:13 ` Thomas Bogendoerfer
2021-04-26 10:29 ` [PATCH v4 1/2] gpio: Add support for IDT 79RC3243x " Andy Shevchenko
2021-04-27 22:51 ` Michael Walle
2021-04-28 11:07 ` Andy Shevchenko
2021-04-28 11:57 ` Michael Walle
2021-04-28 13:44 ` Andy Shevchenko
2021-04-28 14:04 ` Michael Walle [this message]
2021-04-28 14:32 ` Andy Shevchenko
2021-04-28 14:48 ` Michael Walle
2021-04-28 15:02 ` Andy Shevchenko
2021-04-28 15:07 ` Michael Walle
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=880011ffd80ae7d1a32e7a17d405b987@walle.cc \
--to=michael@walle.cc \
--cc=andy.shevchenko@gmail.com \
--cc=bgolaszewski@baylibre.com \
--cc=linus.walleij@linaro.org \
--cc=linux-gpio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tsbogend@alpha.franken.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).