[Intel-gfx] [RFC PATCH 3/9] drm/i915/spi: add driver for on-die spi device

[Winkler, Tomas]

> 
> On Wed, Feb 17, 2021 at 08:58:12PM +0000, Winkler, Tomas wrote:
> >>
> >> On Tue, 16 Feb 2021, Tomas Winkler <tomas.winkler at intel.com> wrote:
> >> > Add the platform driver for i915 on-die spi device, exposed via mfd
> >> > framework.
> >> >
> >> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> >> > Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> >> > Signed-off-by: Tomas Winkler <tomas.winkler at intel.com>
> >> > ---
> >> >  drivers/gpu/drm/i915/Kconfig             |   2 +
> >> >  drivers/gpu/drm/i915/Makefile            |   3 +
> >> >  drivers/gpu/drm/i915/spi/intel_spi_drv.c | 116
> >> > +++++++++++++++++++++++
> >> >  3 files changed, 121 insertions(+)  create mode 100644
> >> > drivers/gpu/drm/i915/spi/intel_spi_drv.c
> >> >
> >> > diff --git a/drivers/gpu/drm/i915/Kconfig
> >> > b/drivers/gpu/drm/i915/Kconfig index abcaa8da45ac..13c870e5878e
> >> > 100644
> >> > --- a/drivers/gpu/drm/i915/Kconfig
> >> > +++ b/drivers/gpu/drm/i915/Kconfig
> >> > @@ -27,6 +27,8 @@ config DRM_I915
> >> >  	select CEC_CORE if CEC_NOTIFIER
> >> >  	select VMAP_PFN
> >> >  	select MFD_CORE
> >> > +	select MTD
> >>
> >> Selecting MTD does not seem to be a popular thing to do, which is
> >> usually a clue it's probably the wrong thing to do.
> >Depends, if it is not selected you'll end with wrongly configured system.
> 
> no. I believe the idea is that having a CONFIG_I915_SPI, you could do
> 
> 	depends on MTD
> 
> like the other drivers doing similar thing:
> 
> 	git grep MTD -- ':(exclude)drivers/mtd' ':(exclude)arch/' '*Kconfig'
 I know the pattern and it can be done, the issue is that mtd is used mostly in embedded systems so it is not selected by the desktop distros.
The intel spi both on PCH and in GFX takes this into different direction and usage.

Thanks
Tomas