RE: [PATCH 00/10] drm/i915/spi: spi access for discrete graphics

Usyskin, Alexander
2023-09-20T13:52:38Z

> > > > No SPI controllers are directly visible to userspace, some SPI devices
> > > > are selectively exposed but that needs to be explicitly requested and is
> > > > generally discouraged.
>
> > > What are the options here? Explicitly request exception is the one.
> > > Any other way to add access to flash memory connected in such way?
>
> > Register a spi controller with at least spi-mem ops, as suggested
> > previously, is the standard way I guess. If you're not willing to do
> > so, it must be justified, I guess?
>
> Right, we already have a way of describing flash chips so that should be
> used to describe any flash chips.

Hi

I've tried to register spi controller with a spi-mem ops, but I can't find a way to connect to mtd subsystem.
I took spi-intel as example, which connects to spi-nor but it relies on JDEC ID of flash to configure itself.
We have predefined set of operations unrelated to flash behind the controller.
What is the right way to simulate the general operations?
Should I add dummy flash device? Or there is another option to connect spi-mem-only controller to mtd?
Or this is too much and warrant the exception to have direct MTD device?

--
Thanks,
Sasha