[RFC v8 net-next 08/16] mfd: ocelot: add support for the vsc7512 chip via spi

[Colin Foster]

On Mon, May 09, 2022 at 05:20:29PM +0000, Vladimir Oltean wrote:
> On Mon, May 09, 2022 at 04:49:22PM -0700, Colin Foster wrote:
> > > > +struct regmap *ocelot_init_regmap_from_resource(struct device *child,
> > > > +						const struct resource *res)
> > > > +{
> > > > +	struct device *dev = child->parent;
> > > > +
> > > > +	return ocelot_spi_devm_init_regmap(dev, child, res);
> > > 
> > > So much for being bus-agnostic :-/
> > > Maybe get the struct ocelot_ddata and call ocelot_spi_devm_init_regmap()
> > > via a function pointer which is populated by ocelot-spi.c? If you do
> > > that don't forget to clean up drivers/mfd/ocelot.h of SPI specific stuff.
> > 
> > That was my initial design. "core" was calling into "spi" exclusively
> > via function pointers.
> > 
> > The request was "Please find a clearer way to do this without function
> > pointers"
> > 
> > https://lore.kernel.org/netdev/Ydwju35sN9QJqJ%2FP@google.com/
> 
> Yeah, I'm not sure what Lee was looking for, either. In any case I agree
> with the comment that you aren't configuring a bus. In this context it
> seems more appropriate to call this function pointer "init_regmap", with
> different implementations per transport.
> 
> Or alternatively you could leave the "core"/"spi" pseudo-separation up
> to the next person who needs to add support for some other register I/O
> method.

That's true. If it comes down to it I can do that. Though I really do
like having the SPI-specific stuff clearly separated, I can bring them
together if it speeds things up. I'll wait for feedback.