Re: [PATCH v2 3/4] iio: vcnl4000: Export near level property for proximity sensor

Lars-Peter Clausen
2020-03-17T13:11:50Z

On 3/17/20 1:05 PM, Guido Günther wrote:
> Hi,
> On Mon, Mar 16, 2020 at 07:23:01PM +0100, Lars-Peter Clausen wrote:
>> On 3/16/20 6:46 PM, Guido Günther wrote:
>>> [...]
>>> +static ssize_t vcnl4000_read_near_level(struct iio_dev *indio_dev,
>>> + uintptr_t priv,
>>> + const struct iio_chan_spec *chan,
>>> + char *buf)
>>> +{
>>> + struct vcnl4000_data *data = iio_priv(indio_dev);
>>> +
>>> + return sprintf(buf, "%u\n", data->near_level);
>>> +}
>>> +
>>> +static const struct iio_chan_spec_ext_info vcnl4000_ext_info[] = {
>>> + {
>>> + .name = "near_level",
>> Generally having properties with a underscore in them breaks generic parsing
>> of the property name by userspace applications. This is because we use
>> underscores to separate different components (type, modifier, etc.) of the
>> attribute from each other.
>>
>> Do you think calling this "nearlevel" would work?
> That works as well. I'll change that for v3.
>
> For my education: Is the type, modifier policy written down somewhere
> (similar to
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/leds/leds-class.rst#n44
> )?

Good point, this is quite badly documented at the moment.

The only thing I could find is this presentation by Daniel
https://events.static.linuxfound.org/sites/events/files/slides/lceu15_baluta.pdf#page=9

- Lars