On Mon, 09 May 2022, Vladimir Oltean wrote:

On Mon, May 09, 2022 at 04:49:22PM -0700, Colin Foster wrote:

quoted

quoted

quoted

+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/ (local)

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.

FWIW, I'm still against using function pointers for this.

What about making ocelot_init_regmap_from_resource() an inline
function and pushing it into one of the header files?

[As an aside, you don't need to pass both dev (parent) and child]

In there you could simply do:

inline struct regmap *ocelot_init_regmap_from_resource(struct device *dev,
						       const struct resource *res)
{
	if (dev_get_drvdata(dev->parent)->spi)
		return ocelot_spi_devm_init_regmap(dev, res);

	return NULL;
}

Also, do you really need devm in the title?

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.

Or this.  Your call.

-- 
Lee Jones [李琼斯]
Principal Technical Lead - Developer Services
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