Re: [PATCH v2 3/4] mfd: add support for Allwinner SoCs ADC

[Jonathan Cameron]

On 19/07/16 08:31, Lee Jones wrote:
> On Mon, 18 Jul 2016, Jonathan Cameron wrote:
> 
>> On 15/07/16 10:59, Quentin Schulz wrote:
>>> The Allwinner SoCs all have an ADC that can also act as a touchscreen
>>> controller and a thermal sensor. For now, only the ADC and the thermal
>>> sensor drivers are probed by the MFD, the touchscreen controller support
>>> will be added later.
>>>
>>> Signed-off-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>
>> Hmm. Previous patch includes the header this one creates.  Ordering issue?
>> The depends kind of prevents build failures by ensuring that can't be built
>> until this one is in place, but it is certainly an ugly way to do it.
>>
>> Few little bits innline.
>>> ---
>>>
>>> v2:
>>>  - add license headers,
>>>  - reorder alphabetically includes,
>>>  - add SUNXI_GPADC_ prefixes for defines,
>>>
>>>  drivers/mfd/Kconfig                 |  14 +++
>>>  drivers/mfd/Makefile                |   2 +
>>>  drivers/mfd/sunxi-gpadc-mfd.c       | 197 ++++++++++++++++++++++++++++++++++++
>>>  include/linux/mfd/sunxi-gpadc-mfd.h |  23 +++++
>>>  4 files changed, 236 insertions(+)
>>>  create mode 100644 drivers/mfd/sunxi-gpadc-mfd.c
>>>  create mode 100644 include/linux/mfd/sunxi-gpadc-mfd.h
> 
> [...]
> 
>>> +static struct mfd_cell sun6i_gpadc_mfd_cells[] = {
>>> +	{
>>> +		.name	= "sun6i-a31-gpadc-iio",
>>> +		.resources = adc_resources,
>>> +		.num_resources = ARRAY_SIZE(adc_resources),
>>> +	}, {
>>> +		.name = "iio_hwmon",
>> I still really dislike using this to force the probe of that driver but
>> kind of up to the hwmon / mfd guys on this.
> 
> Can you at least say *why* you don't like it?
It just feels odd to have an mfd child that isn't really dependent
on the mfd hardware itself.

Still if you are happy, mfd is your domain and my objections were
as you probably noticed not that strong - or well described!)

So I'm fine with this.
> 
> How else would it get probed?
> 
>> I don't have any better suggestions though..
>>> +	},
>>> +};
> 
> [...]
> 
>>> +	if (ret) {
>>> +		dev_err(&pdev->dev, "failed to add MFD devices: %d\n", ret);
>>> +		regmap_del_irq_chip(irq, sunxi_gpadc_mfd_dev->regmap_irqc);
>>> +		return ret;
>>> +	}
>>> +
>>> +	dev_info(&pdev->dev, "successfully loaded\n");
>> Seems like noise to me, but not my subsystem :)
> 
> Agreed, I don't allow this either.
> 
> [...]
>