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From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Asmaa Mnebhi <asmaa@nvidia.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
	"bgolaszewski@baylibre.com" <bgolaszewski@baylibre.com>,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
	"linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>
Subject: Re: [PATCH v1 1/1] Add driver for Mellanox BlueField-3 GPIO controller
Date: Tue, 6 Sep 2022 18:35:09 +0300	[thread overview]
Message-ID: <CAHp75VfLjvEVsFqw2+fu8M60uU4LEbsirg7vBKdHd7WsxWN5Rw@mail.gmail.com> (raw)
In-Reply-To: <CH2PR12MB3895981F3DBB2F551DA6AE95D77E9@CH2PR12MB3895.namprd12.prod.outlook.com>

On Tue, Sep 6, 2022 at 5:08 PM Asmaa Mnebhi <asmaa@nvidia.com> wrote:
> -----Original Message-----
> From: Linus Walleij <linus.walleij@linaro.org>
> Sent: Friday, September 2, 2022 5:55 PM
> On Fri, Sep 2, 2022 at 5:55 PM Asmaa Mnebhi <asmaa@nvidia.com> wrote:

...

> > I would like that to be controlled by the ACPI table only.
>
> I don't know if it is possible to restrict GPIOs to just be used from ACPI.

On Intel platforms that's done with HW assistance, i.e. firmware
configures special registers inside pin control / GPIO address space
that reflect ownership. The driver rejects any attempts to request
such GPIOs. As a workaround one may simply disable all user space
interfaces (as you already discussed in this thread).

-- 
With Best Regards,
Andy Shevchenko

      reply	other threads:[~2022-09-06 16:11 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-18 14:14 [PATCH v1 1/1] Add driver for Mellanox BlueField-3 GPIO controller Asmaa Mnebhi
2022-05-05 14:14 ` Asmaa Mnebhi
2022-05-05 15:11   ` Linus Walleij
2022-05-05 17:01     ` Asmaa Mnebhi
2022-05-05 18:04       ` Andy Shevchenko
2022-05-12 20:38       ` Linus Walleij
2022-05-12 20:45         ` Asmaa Mnebhi
2022-05-13 20:58           ` Linus Walleij
2022-05-16 13:00             ` Asmaa Mnebhi
2022-05-18 13:51               ` Linus Walleij
2022-05-18 14:05                 ` Asmaa Mnebhi
2022-09-02 15:54                 ` Asmaa Mnebhi
2022-09-02 21:55                   ` Linus Walleij
2022-09-06 14:08                     ` Asmaa Mnebhi
2022-09-06 15:35                       ` Andy Shevchenko [this message]

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