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From: Drew Fustini <pdp7pdp7@gmail.com>
To: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Subject: Re: [RFC] gpio: expose pull-up/pull-down line flags to userspace
Date: Wed, 2 Oct 2019 13:10:39 +0200
Message-ID: <CAEf4M_AaSRppq06G4yfQ=+=8JzqPRq1+D+Sp=o+16+VKVdOY=Q@mail.gmail.com> (raw)
In-Reply-To: <CAMRc=Me=6JeOOv_SRhKt+vOsd3p5yOVkWyNu4Oo+DeCwMJHmaA@mail.gmail.com>

On Mon, Sep 23, 2019 at 10:38 AM Bartosz Golaszewski <brgl@bgdev.pl> wrote:
> I remember discussing it with Linus some time ago. This may not be as
> straightforward as simply adding new flags. Since PULL-UP/DOWN
> resistors can - among other parameters - also have configurable
> resistance, we'll probably need some kind of a structure for this
> ioctl() to pass any additional information to the kernel. Since we
> can't change ABI this may require adding a whole new ioctl() for
> extended configuration. This in turn has to be as future-proof as
> possible - if someone asks for user-space-configurable drive-strength,
> the new ioctl() should be ready for it.

Thanks for the insight, Bartosz.  Would you be able to point me to the
discussion if is available in an archive?  I would like to improve my
understanding.

What do you think of adding pull-up/down flags first, and then
implementing the extended configuration ioctl() later if necessary?

Thank you,
Drew

  reply index

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-21 10:25 Drew Fustini
2019-09-23  8:38 ` Bartosz Golaszewski
2019-10-02 11:10   ` Drew Fustini [this message]
2019-10-03 12:47   ` Linus Walleij
2019-10-04  7:22     ` Bartosz Golaszewski
2019-10-04 12:46       ` Bartosz Golaszewski
2019-10-05 17:02       ` Linus Walleij
2019-10-06  3:12         ` Kent Gibson
2019-10-06 21:06           ` Linus Walleij
2019-10-07  4:37             ` Kent Gibson
2019-10-08  6:15 ` Kent Gibson
2019-10-08 20:56   ` Bartosz Golaszewski
2019-10-08 23:21     ` Kent Gibson
2019-10-08 23:30       ` Bartosz Golaszewski
2019-10-08 23:56         ` Kent Gibson
2019-10-09  0:03           ` Bartosz Golaszewski
2019-10-09  0:22             ` Kent Gibson
2019-10-09  6:55               ` Kent Gibson
2019-10-09 12:57                 ` Drew Fustini
2019-10-09 13:23                   ` Kent Gibson
2019-10-09 13:30                 ` Drew Fustini
2019-10-09 14:11                   ` Kent Gibson
2019-10-09 15:50                     ` Bartosz Golaszewski
2019-10-09 16:19                       ` Kent Gibson
2019-10-09 23:59                   ` Kent Gibson
2019-10-10  7:47                     ` Drew Fustini
2019-10-10 10:14                       ` Kent Gibson
2019-10-10 11:17                         ` Kent Gibson
2019-10-11 13:04                           ` Drew Fustini
2019-10-11 13:06                         ` Drew Fustini
2019-10-11 13:49                           ` Kent Gibson
2019-10-09 11:32               ` Drew Fustini
2019-10-09 13:57       ` Drew Fustini
2019-10-09 14:01         ` Kent Gibson
2019-10-09 11:46   ` Drew Fustini

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