>>> 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 ? The use case we are interested in is to enable IPMI SSIF on the arm virt machine which is why I was interested in something with ACPI support. That particular IPMI SSIF enablement patch is not in this series but I think it could be pulled into the series if necessary. > > >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 ? I’m not aware of any standalone PCI I2C controllers. I’ve seen I2C controllers on PCI devices with other things but I don’t think those could be used for IPMI SSIF or other general I2C use cases. Do you know of a particular device I should take a look at? -Chris On Wed, Jan 26, 2022 at 10:03 AM Peter Maydell <peter.mayd...@linaro.org> wrote: > On Wed, 26 Jan 2022 at 17:12, Chris Rauer <cra...@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 ? > > thanks > -- PMM >
