Re: [RFC PATCH 14/14] mfd/macsmc: add ioctl to access smc keys

[Jonathan Cameron]

On Thu, 29 Oct 2026 04:52:11 -0400
Atharva Tiwari <atharvatiwarilinuxdev@xxxxxxxxx> wrote:

> Add a /dev/smc device so userspace can talk to the SMC
> directly. Some keys that need to be written aren't handled by
> any driver, or affect several drivers at once, so they
> can't be exposed cleanly through the kernel interfaces.
> 
> Keys already managed by kernel drivers can't be written this
> way, to avoid conflicts.

If this isn't matching some legacy interface, then we need more
on what these do.  Maybe they are suited to some other kernel
interface? In particular they might need the various controls
on how destructive they are that something like fwctl brings.

Generally an arbitrary opaque path to firmware isn't a good idea...

Jonathan