Re: [PATCH 6/6] staging:iio: attrs/event_attrs -> struct attribute * + move to iio_dev.

[Jonathan Cameron <jic23@kernel.org>]

On 01/12/2012 07:29 PM, Jonathan Cameron wrote:
> On 01/09/2012 10:14 AM, Lars-Peter Clausen wrote:
>> On 01/07/2012 11:25 AM, Jonathan Cameron wrote:
>>>
>>> diff --git a/drivers/staging/iio/adc/ad7606_core.c
>> b/drivers/staging/iio/adc/ad7606_core.c
>>> index 97e8d3d..99d91ee 100644
>>> --- a/drivers/staging/iio/adc/ad7606_core.c
>>> +++ b/drivers/staging/iio/adc/ad7606_core.c
>>> @@ -205,30 +205,18 @@ static struct attribute
>> *ad7606_attributes_os_and_range[] = {
>>>  	NULL,
>>>  };
>>>
>>> -static const struct attribute_group ad7606_attribute_group_os_and_range = {
>>> -	.attrs = ad7606_attributes_os_and_range,
>>> -};
>>> -
>>>  static struct attribute *ad7606_attributes_os[] = {
>>>  	&iio_dev_attr_oversampling_ratio.dev_attr.attr,
>>>  	&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
>>>  	NULL,
>>>  };
>>>
>>> -static const struct attribute_group ad7606_attribute_group_os = {
>>> -	.attrs = ad7606_attributes_os,
>>> -};
>>> -
>>>  static struct attribute *ad7606_attributes_range[] = {
>>>  	&iio_dev_attr_in_voltage_range.dev_attr.attr,
>>>  	&iio_const_attr_in_voltage_range_available.dev_attr.attr,
>>>  	NULL,
>>>  };
>>>
>>> -static const struct attribute_group ad7606_attribute_group_range = {
>>> -	.attrs = ad7606_attributes_range,
>>> -};
>>> -
>>>  #define AD7606_CHANNEL(num)				\
>>>  	{						\
>>>  		.type = IIO_VOLTAGE,			\
>>> @@ -429,27 +417,9 @@ static irqreturn_t ad7606_interrupt(int irq, void
>> *dev_id)
>>>  	return IRQ_HANDLED;
>>>  };
>>>
>>> -static const struct iio_info ad7606_info_no_os_or_range = {
>>> -	.driver_module = THIS_MODULE,
>>> -	.read_raw = &ad7606_read_raw,
>>> -};
>>> -
>>> -static const struct iio_info ad7606_info_os_and_range = {
>>> -	.driver_module = THIS_MODULE,
>>> -	.read_raw = &ad7606_read_raw,
>>> -	.attrs = &ad7606_attribute_group_os_and_range,
>>> -};
>>> -
>>> -static const struct iio_info ad7606_info_os = {
>>> +static const struct iio_info ad7606_info = {
>>>  	.driver_module = THIS_MODULE,
>>>  	.read_raw = &ad7606_read_raw,
>>> -	.attrs = &ad7606_attribute_group_os,
>>> -};
>>> -
>>> -static const struct iio_info ad7606_info_range = {
>>> -	.driver_module = THIS_MODULE,
>>> -	.read_raw = &ad7606_read_raw,
>>> -	.attrs = &ad7606_attribute_group_range,
>>>  };
>>>
>>>  struct iio_dev *ad7606_probe(struct device *dev, int irq,
>>> @@ -494,19 +464,16 @@ struct iio_dev *ad7606_probe(struct device *dev, int
>> irq,
>>>  	st->chip_info = &ad7606_chip_info_tbl[id];
>>>
>>>  	indio_dev->dev.parent = dev;
>>> +	indio_dev->info = &ad7606_info;
>>>  	if (gpio_is_valid(st->pdata->gpio_os0) &&
>>>  	    gpio_is_valid(st->pdata->gpio_os1) &&
>>>  	    gpio_is_valid(st->pdata->gpio_os2)) {
>>>  		if (gpio_is_valid(st->pdata->gpio_range))
>>> -			indio_dev->info = &ad7606_info_os_and_range;
>>> +			indio_dev->attrs = ad7606_attributes_os_and_range;
>>>  		else
>>> -			indio_dev->info = &ad7606_info_os;
>>> -	} else {
>>> -		if (gpio_is_valid(st->pdata->gpio_range))
>>> -			indio_dev->info = &ad7606_info_range;
>>> -		else
>>> -			indio_dev->info = &ad7606_info_no_os_or_range;
>>> -	}
>>> +			indio_dev->attrs = ad7606_attributes_os;
>>> +	} else if (gpio_is_valid(st->pdata->gpio_range))
>>> +			indio_dev->attrs = ad7606_attributes_range;
>>>  	indio_dev->modes = INDIO_DIRECT_MODE;
>>>  	indio_dev->name = st->chip_info->name;
>>>  	indio_dev->channels = st->chip_info->channels;
>>
>> This makes me wonder if we not better add a function which can add a single
>> attribute to the attribute list at runtime. Or maybe just use
>> device_create_file directly.
> Device create file is out I think. It can only be applied after a the
> group has been created (so after the iio registration is done)  The
> whole issue is that udev doesn't get notified of such creations.  That's
> why we jumped through these hoops in the first place.
> (I've never entirely understood why this is the case, but Kay and
> Greg both assured me it was the case - only reliable option is to
> add all files on device registration as here.)  Yes, lots of the
> kernel doesn't do that, but they were strongly in favour of it for
> any new code.
> 
> We could add our own function, but personally I'm against it.  In the
> vast majority of cases it is irrelevant and we have this approach for
> those where it might be a small clean up.  If these get more common
> then I'll come around to such a function with the slight additional
> complexity it would need.
> 
> So in my view a question for another day!
Note this series no longer applies due to a series changing return type
of is_visible.  Obviously we just delete the new versions though so
I'm not going to repost for that!