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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Tue, 15 Jun 2021 13:37:35 +0200
Message-ID: <CAMuHMdUKNgRgH+=fHW9RZijdFT9syPu-FD=EyA-PkrtUrg3AdQ@mail.gmail.com>
Subject: Re: [PATCH V3 1/3] gpio: Add virtio-gpio driver
To:     Viresh Kumar <viresh.kumar@linaro.org>
Cc:     Linus Walleij <linus.walleij@linaro.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        "Enrico Weigelt, metux IT consult" <info@metux.net>,
        Viresh Kumar <vireshk@kernel.org>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Bill Mills <bill.mills@linaro.org>,
        =?UTF-8?B?QWxleCBCZW5uw6ll?= <alex.bennee@linaro.org>,
        stratos-dev@op-lists.linaro.org,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Stefan Hajnoczi <stefanha@redhat.com>,
        "Stefano Garzarella --cc virtualization @ lists . linux-foundation . org" 
        <sgarzare@redhat.com>, virtualization@lists.linux-foundation.org,
        Alistair Strachan <astrachan@google.com>,
        Wolfram Sang <wsa+renesas@sang-engineering.com>
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Hi Viresh,

On Tue, Jun 15, 2021 at 1:15 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
> On 11-06-21, 10:22, Geert Uytterhoeven wrote:
> > The same reasoning can apply to your backend daemon, so when using
> > the GPIO aggregator, you can just control a full gpiochip, without
> > having to implement access control on individual GPIO lines.
>
> I tried to look at it and it surely looks very temping and may fit
> well and reduce size of my backend :)
>
> I am now wondering how interrupts can be made to work here. Do you
> have anything in mind for that ?
>
> GPIO sysfs already supports interrupts, just that you need to register
> irq for the specific GPIO pins inside the aggregator ?

So far I hadn't considered interrupts.
Will think about it...

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds