Re: [PATCH 16/34] brcmfmac: acpi: Add support for fetching Apple ACPI properties

[Hector Martin]

On 2022/01/02 14:58, Linus Walleij wrote:
> On Sun, Dec 26, 2021 at 4:38 PM Hector Martin <marcan@xxxxxxxxx> wrote:
> 
>> On DT platforms, the module-instance and antenna-sku-info properties
>> are passed in the DT. On ACPI platforms, module-instance is passed via
>> the analogous Apple device property mechanism, while the antenna SKU
>> info is instead obtained via an ACPI method that grabs it from
>> non-volatile storage.
>>
>> Add support for this, to allow proper firmware selection on Apple
>> platforms.
>>
>> Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
> 
> If the strings treated here are exactly the same as for the device tree,
> you should be able to just use "devprops" (firmware node) to handle it
> abstractly, and then the respective DT and ACPI backend will provide
> the properties.
> 
> I don't know if this patch I made recently is enough of an examples:
> https://lore.kernel.org/linux-hwmon/20211206020423.62402-2-linus.walleij@xxxxxxxxxx/
> 
> If the ACPI and DT differs a lot in format and strings etc it may not
> be worth it.

It's not quite the same; module-instance is the same from macOS'
perspective, but we don't use Apple's device tree directly but rather
roll our own DT which uses a different property name in this case.
antenna-sku-info uses an ACPI method on x86, so that one is completely
different. So in the end nothing is actually shared.

-- 
Hector Martin (marcan@xxxxxxxxx)
Public Key: https://mrcn.st/pub