From: Eugeniu Rosca <erosca@de.adit-jv.com>
To: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Linus Walleij <linus.walleij@linaro.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Jonathan Corbet <corbet@lwn.net>,
Harish Jenny K N <harish_kandiga@mentor.com>,
Alexander Graf <graf@amazon.com>,
Peter Maydell <peter.maydell@linaro.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Phil Reid <preid@electromag.com.au>,
Marc Zyngier <marc.zyngier@arm.com>,
Christoffer Dall <christoffer.dall@arm.com>,
Magnus Damm <magnus.damm@gmail.com>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>, <linux-gpio@vger.kernel.org>,
<linux-doc@vger.kernel.org>, <linux-renesas-soc@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <qemu-devel@nongnu.org>,
Eugeniu Rosca <erosca@de.adit-jv.com>,
Eugeniu Rosca <roscaeugeniu@gmail.com>
Subject: Re: [PATCH v5 0/5] gpio: Add GPIO Aggregator
Date: Tue, 18 Feb 2020 18:04:27 +0100 [thread overview]
Message-ID: <20200218170427.GA7423@lxhi-065.adit-jv.com> (raw)
In-Reply-To: <20200218151812.7816-1-geert+renesas@glider.be>
Hi Geert,
On Tue, Feb 18, 2020 at 04:18:07PM +0100, Geert Uytterhoeven wrote:
> Hi all,
>
> GPIO controllers are exported to userspace using /dev/gpiochip*
> character devices. Access control to these devices is provided by
> standard UNIX file system permissions, on an all-or-nothing basis:
> either a GPIO controller is accessible for a user, or it is not.
> Currently no mechanism exists to control access to individual GPIOs.
>
> Hence this adds a GPIO driver to aggregate existing GPIOs, and expose
> them as a new gpiochip. This is useful for implementing access control,
> and assigning a set of GPIOs to a specific user. Furthermore, this
> simplifies and hardens exporting GPIOs to a virtual machine, as the VM
> can just grab the full GPIO controller, and no longer needs to care
> about which GPIOs to grab and which not, reducing the attack surface.
>
> Recently, other use cases have been discovered[1]:
> - Describing simple GPIO-operated devices in DT, and using the GPIO
> Aggregator as a generic GPIO driver for userspace, which is useful
> for industrial control.
>
> Changes compared to v4[2]:
> - Add Reviewed-by, Tested-by,
> - Fix inconsistent indentation in documentation.
I confirm that the diff between v4 and v5 comprises whitespace only.
Thanks for your time to develop this useful functionality!
--
Best Regards
Eugeniu Rosca
next prev parent reply other threads:[~2020-02-18 17:04 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-18 15:18 [PATCH v5 0/5] gpio: Add GPIO Aggregator Geert Uytterhoeven
2020-02-18 15:18 ` [PATCH v5 1/5] gpiolib: Add support for gpiochipN-based table lookup Geert Uytterhoeven
2020-03-12 14:23 ` Linus Walleij
2020-03-17 8:41 ` Geert Uytterhoeven
2020-02-18 15:18 ` [PATCH v5 2/5] gpiolib: Add support for GPIO line " Geert Uytterhoeven
2020-02-19 10:17 ` Geert Uytterhoeven
2020-03-12 14:21 ` Linus Walleij
2020-03-17 8:48 ` Geert Uytterhoeven
2020-02-18 15:18 ` [PATCH v5 3/5] gpio: Add GPIO Aggregator Geert Uytterhoeven
2020-03-12 14:57 ` Linus Walleij
2020-03-17 10:50 ` Geert Uytterhoeven
2020-03-17 11:32 ` Geert Uytterhoeven
2020-02-18 15:18 ` [PATCH v5 4/5] docs: gpio: Add GPIO Aggregator documentation Geert Uytterhoeven
2020-02-18 18:29 ` Randy Dunlap
2020-02-18 19:09 ` Geert Uytterhoeven
2020-02-21 16:34 ` Geert Uytterhoeven
2020-02-21 16:35 ` Randy Dunlap
2020-02-18 15:18 ` [PATCH v5 5/5] MAINTAINERS: Add GPIO Aggregator section Geert Uytterhoeven
2020-02-18 17:04 ` Eugeniu Rosca [this message]
2020-02-21 16:39 ` [PATCH v5 0/5] gpio: Add GPIO Aggregator Geert Uytterhoeven
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