Re: [PATCH v2 4/4] iio/adc/axp288: add support for axp288 gpadc

[Jacob Pan <jacob.jun.pan@linux.intel.com>]

On Fri, 19 Sep 2014 10:31:10 -0700
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> wrote:

> On Fri, 2014-09-19 at 09:43 -0700, Jacob Pan wrote:
> > On Tue, 9 Sep 2014 15:46:31 +0200 (CEST)
> > Peter Meerwald <pmeerw@pmeerw.net> wrote:
> > 
> > > > +static int axp288_gpadc_remove(struct platform_device *pdev)
> > > > +{
> > > > +	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> > > > +
> > > > +	iio_device_unregister(indio_dev);
> > > > +	iio_map_array_unregister(indio_dev);  
> > > 
> > > axp288_gpadc_enable(axp2xx->regmap, false);
> > on a second thought, we should not disable the adc even on driver
> > removal. otherwise, internal fuel gauge will be affected.
> As an independent driver it should disable when driver is removed and
> bring back to state before init. You can check the state at init and
> restore to that state on exit.
> If the FG or other driver has dependency then either it should use the
> driver model to take reference by not allowing removal of this driver.
> Or use built in module so that it can never be removed.
>  
I share you opinion. But in this case, ideally ADCs should have been
enabled by FW since it should be always on, independent of fuel gauge
driver.
> Isn't it a platform specific dependency not universal?
> 
it is more PMIC specific since its internal fuel gauge depends on ADC
to be available regardless of what platform.
> Thanks,
> Srinivas
>  
> 

[Jacob Pan]