From: Kent Gibson <warthog618@gmail.com>
To: Stefan Wahren <wahrenst@gmx.net>
Cc: Linus Walleij <linus.walleij@linaro.org>,
Florian Fainelli <florian.fainelli@broadcom.com>,
bcm-kernel-feedback-list@broadcom.com,
Ray Jui <rjui@broadcom.com>,
Scott Branden <sbranden@broadcom.com>,
linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
Bartosz Golaszewski <brgl@bgdev.pl>,
Phil Elwell <phil@raspberrypi.com>
Subject: Re: [PATCH] pinctrl: bcm2835: Make pin freeing behavior configurable
Date: Thu, 2 May 2024 19:15:46 +0800 [thread overview]
Message-ID: <20240502111546.GA325017@rigel> (raw)
In-Reply-To: <79627aeb-8151-430c-98f4-5689fd61413f@gmx.net>
On Thu, May 02, 2024 at 01:11:06PM +0200, Stefan Wahren wrote:
> Hi Kent,
>
> Am 02.05.24 um 13:04 schrieb Kent Gibson:
> > On Thu, May 02, 2024 at 12:22:07PM +0200, Stefan Wahren wrote:
> > > Am 19.04.24 um 22:40 schrieb Stefan Wahren:
> > > > Until now after a bcm2835 pin was freed its pinmux was set to GPIO_IN.
> > > > So in case it was configured as GPIO_OUT before the configured output
> > > > level also get lost. As long as GPIO sysfs was used this wasn't
> > > > actually a problem because the pins and their possible output level
> > > > were kept by sysfs.
> > > >
> > > > Since more and more Raspberry Pi users start using libgpiod they are
> > > > confused about this behavior. So make the pin freeing behavior of
> > > > GPIO_OUT configurable via module parameter. In case
> > > > pinctrl-bcm2835.strict_gpiod is set to 0, the output level is kept.
> > > >
> > > > This patch based on the downstream work of Phil Elwell.
> > > >
> > > > Link: https://github.com/raspberrypi/linux/pull/6117
> > > > Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
> > > > ---
> > > > drivers/pinctrl/bcm/pinctrl-bcm2835.c | 20 ++++++++++++++++----
> > > > 1 file changed, 16 insertions(+), 4 deletions(-)
> > > Gentle ping ...
> > I can't comment on the substance of the change as pinctrl is outside my
> > wheelhouse, but the "strict_gpiod" name could be better.
> > The point is to make GPIO outputs persist, right?
> Yes, correct.
> > The name should better reflect that.
> Finding good and short names is hard, do you have a suggestion?
>
How about "persist_gpio_outputs"?
Cheers,
Kent.
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next prev parent reply other threads:[~2024-05-02 11:16 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-19 20:40 [PATCH] pinctrl: bcm2835: Make pin freeing behavior configurable Stefan Wahren
2024-05-02 10:22 ` Stefan Wahren
2024-05-02 11:04 ` Kent Gibson
2024-05-02 11:11 ` Stefan Wahren
2024-05-02 11:15 ` Kent Gibson [this message]
2024-05-02 12:20 ` Stefan Wahren
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