From: "Philippe Mathieu-Daudé via" <qemu-devel@nongnu.org>
To: Peter Maydell <peter.maydell@linaro.org>,
Chris Rauer <crauer@google.com>
Cc: mst@redhat.com, Patrick Venture <venture@google.com>,
qemu-devel@nongnu.org, shannon.zhaosl@gmail.com,
qemu-arm@nongnu.org, ani@anisinha.ca, imammedo@redhat.com,
Enrico Weigelt <info@metux.net>
Subject: Re: [PATCH 0/2] Adds designware i2c module and adds it to virt arm
Date: Thu, 27 Jan 2022 00:42:20 +0100 [thread overview]
Message-ID: <fff08204-2cd4-0f35-b23d-85a0eeb3ffd2@amsat.org> (raw)
In-Reply-To: <CAFEAcA9HckDH_7s5fpnHOBFQBi-fDfnhcrJ0Y9-=uDtj0bwuoQ@mail.gmail.com>
+Enrico Weigelt
On 26/1/22 19:03, Peter Maydell wrote:
> On Wed, 26 Jan 2022 at 17:12, Chris Rauer <crauer@google.com> wrote:
>>
>>> I need to see a pretty strong justification for why we should be
>>> adding new kinds of devices to the virt machine,
>>
>> The designware i2c controller is a very common controller on many
>> ARM SoCs. It has device tree bindings and ACPI bindings which
>> makes it ideal for this platform.
>
> No, I mean, why do we need an i2c controller on the virt
> board at all ?
>
>>> Forgot to mention, but my prefered approach for providing
>>> an i2c controller on the virt board would be to have a
>>> PCI i2c controller: that way users who do need it can plug it
>>> in with a -device command line option, and users who don't
>>> need it never have to worry about it.
>
>>> (We seem to have an ICH9-SMB PCI device already; I have no idea if it's suitable.)
>> I didn't find that device suitable because it is part of the Intel
>> Southbridge, which may have some Intel platform quirks, and
>> we don't need all the things in that IO hub.
>
> That's a pity. Is there a different PCI I2C controller we could model ?
What about using virtio-gpio & bitbang I2C?
- virtio-gpio
https://lore.kernel.org/qemu-devel/20201127182917.2387-5-info@metux.net/
- bitbang I2C already in: hw/i2c/bitbang_i2c.c
Regards,
Phil.
next prev parent reply other threads:[~2022-01-26 23:44 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-10 21:47 [PATCH 0/2] Adds designware i2c module and adds it to virt arm Patrick Venture
2022-01-10 21:47 ` [PATCH 1/2] hw/i2c: Add designware i2c controller Patrick Venture
2022-01-10 21:47 ` [PATCH 2/2] hw/arm: Enable smbus on arm virt machine Patrick Venture
2022-01-13 11:48 ` [PATCH 0/2] Adds designware i2c module and adds it to virt arm Peter Maydell
2022-01-13 11:51 ` Peter Maydell
2022-01-26 17:12 ` Chris Rauer
2022-01-26 18:03 ` Peter Maydell
2022-01-26 22:01 ` Chris Rauer
2022-01-26 23:42 ` Philippe Mathieu-Daudé via [this message]
2022-02-21 17:47 ` Chris Rauer
2022-02-22 17:05 ` Corey Minyard
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