Re: [PATCH v9 5/7] ACPI: Translate the I/O range of non-MMIO devices before scanning

Andy Shevchenko
2017-07-03T20:22:47Z

On Mon, Jul 3, 2017 at 7:08 PM, Gabriele Paoloni
<gabriele.paoloni@huawei.com> wrote:

JFYI: Mika on vacation.

> I had a look into the MFD framework. If my understanding is correct the mfd
> framework create a platform device for each declared mfd_cell that is passed
> to mfd_add_devices().

Right.

> However there is something that I do not quite understand:
> from
> http://elixir.free-electrons.com/linux/latest/source/drivers/mfd/mfd-core.c#L207
> it seems that mfd_add_device() will create the platform device using the
> resources that are statically declared in the respective mfd_cell.

It's one possibility.

> In my case I'd like to have a platform device using the resources that are
> parsed from the ACPI table (i.e. as it is done now by
> acpi_create_platform_device()).

So far so good. Nothing prevents you to do that.

> If my understanding is correct, if I declared an mfd_cell for my IPMI child
> the mfd subsystem would create a platform device for such child and
> therefore acpi_create_platform_device() would fail to create a new platform
> device as adev->physical_node_count will be non zero.
> However as things stand now mfd_cell devices can only use the resources
> that are statically defined in the code (and therefore not the ones in the
> ACPI nodes)...am I right?

You may file resources first and then register MFD cells. See many
existing examples in the kernel.

--
With Best Regards,
Andy Shevchenko