Re: [PATCH 1/8] iio: adc: ab8500-gpadc: Allow COMPILE_TEST builds

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 8 Apr 2024 11:16:17 +0200
Linus Walleij <linus.walleij@linaro.org> wrote:

> On Sat, Apr 6, 2024 at 12:27 PM Jonathan Cameron <jic23@kernel.org> wrote:
> > On Fri, 5 Apr 2024 11:36:22 +0100
> > Jonathan Cameron <Jonathan.Cameron@Huawei.com> wrote:
> >  
> > > On Thu, 4 Apr 2024 13:36:15 +0200
> > > Linus Walleij <linus.walleij@linaro.org> wrote:
> > >  
> > > > On Sat, Mar 30, 2024 at 8:09 PM Jonathan Cameron <jic23@kernel.org> wrote:
> > > >  
> > > > > From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > > > >
> > > > > The dependencies on various ab8500 components prevent this driver
> > > > > being useful but they don't seem to prevent it being built.
> > > > > Improve build coverage by allowing COMPILE_TEST.
> > > > >
> > > > > Cc: Linus Walleij <linus.walleij@linaro.org>
> > > > > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>  
> > > >
> > > > ...but I think AB8500_CORE is a hard requirement because
> > > > <linux/mfd/abx500.h> does not provide register accessor stubs?
> > > >  
> > > hmm. I clearly didn't test enough.  Ah well, I'll drop this one.  
> > > > Yours,
> > > > Linus Walleij  
> >
> > Tested again, nope, AB8500_CORE isn't needed as far as I can tell.  
> 
> Oh? Weird.

> 
> > What register accessor stubs were you referring to? There are some calls for debug dumps
> > in that header, but those aren't used by the ADC driver.  
> 
> <linux/mfd/abx500.h> has for example:
> (...)
> int abx500_get_register_interruptible(struct device *dev, u8 bank, u8 reg,
>         u8 *value);
> (...)
> 
> and the ADC driver has:
> 
>         /* Check if ADC is not busy, lock and proceed */
>         do {
>                 ret = abx500_get_register_interruptible(gpadc->dev,
>                         AB8500_GPADC, AB8500_GPADC_STAT_REG, &val);
> 
> 
> $ git grep abx500_get_register_interruptible include/linux/
> include/linux/mfd/abx500.h:int
> abx500_get_register_interruptible(struct device *dev, u8 bank, u8 reg,
> 
> No stubs! I think there is just some other Kconfig stuff bringing the
> AB8500 MFD core into
> the build at any attempt.

ah got it.  AB8500_CORE isn't needed, but ABX500_CORE is and that's indirectly
depended on by AB8500_CORE.  How about I change the dependency to
depends on ABX500_CORE && (AB8500_REGULATOR || COMPILE_TEST) instead?

As ABX500_CORE doesn't have a horrible indirect arch dependency that
AB8500_CORE does via db8500-prcmu.  I can build it on x86 but obviously
would want to hit this with a lot more build tests.

DB8500_PRCMU has some stubs but not a complete enough set to allow
AB5800_CORE to build.  Could fix that but it's a bigger change than
relaxing requirements of the ADC driver to the ones needed for building.

Jonathan


> 
> Yours,
> Linus Walleij