Re: [PATCH v2] iio: hid-sensor-prox: Split difference from multiple channels

Mark Pearson
2025-01-13T19:51:34Z

Note - switched to my open-source friendly email account (avoid the Lenovo address, especially for mailing lists, it's Outlook based and can't cope).

On Mon, Jan 13, 2025, at 2:19 PM, Mark Pearson wrote:
> Subject: [External] Re: [PATCH v2] iio: hid-sensor-prox: Split
> difference from multiple channels
>
> On Sat, 2025-01-11 at 10:17 +0100, Ricardo Ribalda wrote:
>> Hi Jonathan
>>
>> Happy new year!
>>
>> Friendly ping about this patch so we can change the ABI before the
>> kernel release happens
>>
>> On Thu, 19 Dec 2024 at 18:17, Jonathan Cameron <jic23@kernel.org>
>> wrote:
>> >
>> > On Mon, 16 Dec 2024 10:05:53 +0000
>> > Ricardo Ribalda <ribalda@chromium.org> wrote:
>> >
>> > > When the driver was originally created, it was decided that
>> > > sampling_frequency and hysteresis would be shared_per_type
>> > > instead
>> > > of shared_by_all (even though it is internally shared by all).
>> > > Eg:
>> > > in_proximity_raw
>> > > in_proximity_sampling_frequency
>> > >
>> > > When we introduced support for more channels, we continued with
>> > > shared_by_type which. Eg:
>> > > in_proximity0_raw
>> > > in_proximity1_raw
>> > > in_proximity_sampling_frequency
>> > > in_attention_raw
>> > > in_attention_sampling_frequency
>> > >
>> > > Ideally we should change to shared_by_all, but it is not an
>> > > option,
>> > > because the current naming has been a stablished ABI by now.
>> > > Luckily we
>> > > can use separate instead. That will be more consistent:
>> > > in_proximity0_raw
>> > > in_proximity0_sampling_frequency
>> > > in_proximity1_raw
>> > > in_proximity1_sampling_frequency
>> > > in_attention_raw
>> > > in_attention_sampling_frequency
>> > >
>> > > Fixes: 596ef5cf654b ("iio: hid-sensor-prox: Add support for more
>> > > channels")
>> > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
>> >
>> > I got lost somewhere in the discussion. This is still an ABI
>> > change compared
>> > to original interface at the top (which is the one that has been
>> > there
>> > quite some time).
>> >
>> > However we already had to make one of those to add the index that
>> > wasn't there
>> > for _raw. (I'd missed that in earlier discussion - thanks for
>> > laying out the
>> > steps here!)
>
> Didn't realize this. I don't see proximity sensor use in the mainline
> Linux distro user space, so it will affect only some private user space
> programs.
> Adding Mark to see if it affects Lenovo Sensing solution as there was
> specific custom sensor added to this driver for Lenovo.
>

Can I get some pointers to what sensor that is please?
We've been asking for the HID support drivers, but it isn't available yet to my knowledge. Would the MIPI camera work tie into this?

If I can get details on what the sensor is I'll go and check what is impacted.

Thanks
Mark