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Date:   Tue, 15 Jun 2021 22:30:22 -0500
From:   Bjorn Andersson <bjorn.andersson@linaro.org>
To:     Linus Walleij <linus.walleij@linaro.org>
Cc:     Viresh Kumar <viresh.kumar@linaro.org>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        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>,
        Alex Benn?e <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>
Subject: Re: [PATCH V3 1/3] gpio: Add virtio-gpio driver
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On Thu 10 Jun 15:46 CDT 2021, Linus Walleij wrote:
[..]
> Yet another usecase would be to jit this with remoteproc/rpmsg
> and let a specific signal processor or real-time executive on
> another CPU with a few GPIOs around present these to
> Linux using this mechanism. Well that would certainly interest
> Bjorn and other rpmsg stakeholders, so they should have
> a look so that this provides what they need they day they
> need it. (CCed Bjorn and also Google who may want this for
> their Android emulators.)
> 

Right, your typical Qualcomm platform has a dedicated sensor subsystem,
with some CPU core with dedicated I2C controllers and GPIOs for
processing sensor input while the rest of the SoC is in deep sleep.

Combined with the virtio-i2c effort this could provide an alternative by
simply tunneling the busses and GPIOs into Linux and use standard iio
drivers, for cases where this suits your product requirements better.


And I've seen similar interest from others in the community as well.

Regards,
Bjorn