Re: regmap I3C support

[Guenter Roeck]

On 11/19/24 09:46, Mark Brown wrote:
> On Fri, Nov 15, 2024 at 08:35:04PM -0800, Guenter Roeck wrote:
> > On 11/14/24 09:26, Mark Brown wrote:
>
> > > Right, so the fact that I3C depends on I2C deals with a lot of the
> > > problems that plague the I2C/SPI combination.  Ugh.  I guess the helper
> > > should be OK and there's not much doing for I2C/SPI.
>
> > It looks like we can use
>
> >         if (IS_ENABLED(CONFIG_REGMAP_I3C)) {
> >                 regmap = devm_regmap_init_i3c(i3cdev, &tmp108_regmap_config);
> >                 if (IS_ERR(regmap))
> >                         return dev_err_probe(dev, PTR_ERR(regmap),
> >                                              "Failed to register i3c regmap\n");
> > 		...
> > 	}
>
> > even if a stub function is not available as long as there is an external
> > declaration.
>
> > I don't really like it, but it turns out that this kind of code is already used
> > elsewhere in the kernel. It looks like dead code elimination can now assumed
> > to be available when building kernel code. We live and learn.
>
> Ah, that solves that problem then I guess?


Yes. It actually goes a step further - the IS_ENABLED(CONFIG_REGMAP_I3C)) in the
probe function isn't needed either because the entire i3c probe function is
optimized away if CONFIG_I3C=n.

I'll send a patch dropping the #ifdef in the tmp108 driver after the commit
window closes.

Thanks,
Guenter