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

[Jonathan Cameron <jic23@kernel.org>]

On 19/09/14 20:47, Jacob Pan wrote:
> 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.
Whilst irritating this isn't exactly uncommon.
Probably just don't touch it but put a comment in the driver to that
effect so it is obvious this wasn't just an omission.

Jonathan
>> Thanks,
>> Srinivas
>>  
>>
> 
> [Jacob Pan]
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