From: Andy Shevchenko <andy.shevchenko@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>,
Kent Gibson <warthog618@gmail.com>
Subject: Re: [PATCH V2] pinctrl: bcm2835: Make pin freeing behavior configurable
Date: Mon, 6 May 2024 23:31:07 +0300 [thread overview]
Message-ID: <Zjk-C0nLmlynqLAE@surfacebook.localdomain> (raw)
In-Reply-To: <20240503062745.11298-1-wahrenst@gmx.net>
Fri, May 03, 2024 at 08:27:45AM +0200, Stefan Wahren kirjoitti:
> 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.persist_gpio_outputs is set to 1, the output level is
> kept.
>
> This patch based on the downstream work of Phil Elwell.
...
> +static bool persist_gpio_outputs;
> +module_param(persist_gpio_outputs, bool, 0644);
Do you need 'w' attribute?
...
> + dev_info(dev, "GPIO_OUT persistence: %s\n",
> + persist_gpio_outputs ? "yes" : "no");
str_yes_no() and with it can be put on a single line.
--
With Best Regards,
Andy Shevchenko
prev parent reply other threads:[~2024-05-06 20:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-03 6:27 [PATCH V2] pinctrl: bcm2835: Make pin freeing behavior configurable Stefan Wahren
2024-05-06 6:14 ` Linus Walleij
2024-05-06 20:31 ` Andy Shevchenko [this message]
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