iio: vcnl4000: Export near level property for proximity sensor

If an object can be considered close to the device that has the proximity sensor built in is hardware dependent. Allowing to configure the property via device tree allows to export this device specific value to userspace via ext_info. This is useful for e.g. iio-sensor-proxy.

This came up when adding proximity support to iio-sensor-proxy [1], [2], it is not meant as a vcnl4000 thing but rather as something useful for other proximity sensors too in the future.

I've not converted the vcnl4000 binding docs to yaml but can do so as part of this series in a v2 if the approach makes sense.

Changes from v3:
- as per review comment by Jonathan Cameron Fix patch title and description of sysfs patch
https://lore.kernel.org/linux-iio/20200329102705.0a69000c@archlinux/
- Add Reviewed-by by Rob Herring, thanks!
https://lore.kernel.org/linux-iio/20200331214330.GA24010@bogus/
- As per review comments by Rob Herring
https://lore.kernel.org/linux-iio/20200331214517.GA24128@bogus/
- Rename property to proximity-near-level
- document proximity-near-level in a common file

Changes from v2:
- as per review comment by Lars-Peter Clausen
https://lore.kernel.org/linux-iio/[email protected]/
Switch sysfs name to nearlevel
- as per review comment by Nishant Malpani
https://lore.kernel.org/linux-iio/[email protected]/
Add manufacturer do binding document name
- as per review comments by Andy Shevchenko
- Drop superfluous blank line
- Check return value of device_property_read_u32 for '!= 0' instead of '< 0'

Changes from v1:
- as per review comments by Jonathan Cameron
https://lore.kernel.org/linux-iio/20200221120519.43b72007@archlinux/
Document new sysfs file in Documentation/ABI/testing/sysfs-bus-iio-proximity
- convert bindings to yaml
- bindings: fix typo in near-level property

[1]: https://gitlab.freedesktop.org/hadess/iio-sensor-proxy/merge_requests/298
[2]: https://lore.kernel.org/linux-iio/[email protected]/

To: Tomas Novotny <[email protected]>, Jonathan Cameron <[email protected]>,Hartmut Knaack <[email protected]>,Lars-Peter Clausen <[email protected]>,Peter Meerwald-Stadler <[email protected]>,"Angus Ainslie (Purism)" <[email protected]>,"Guido Günther" <[email protected]>,Marco Felsch <[email protected]>,Thomas Gleixner <[email protected]>,[email protected],[email protected],[email protected],Andy Shevchenko <[email protected]>,Nishant Malpani <[email protected]>

Guido Günther (5):
dt-bindings: iio: vcnl4000: convert bindings to YAML format
dt-bindings: iio: Introduce common properties for iio sensors
dt-bindings: iio: light: vcnl4000: Add proximity-near-level
iio: vcnl4000: Export near level property for proximity sensor
Documentation: ABI: document IIO in_proximity_nearlevel file

 .../ABI/testing/sysfs-bus-iio-proximity       | 10 ++++
 .../devicetree/bindings/iio/common.yaml       | 35 +++++++++++++
 .../bindings/iio/light/vcnl4000.txt           | 24 ---------
 .../bindings/iio/light/vishay,vcnl4000.yaml   | 50 +++++++++++++++++++
 drivers/iio/light/vcnl4000.c                  | 25 ++++++++++
 5 files changed, 120 insertions(+), 24 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-proximity
 create mode 100644 Documentation/devicetree/bindings/iio/common.yaml
 delete mode 100644 Documentation/devicetree/bindings/iio/light/vcnl4000.txt
 create mode 100644 Documentation/devicetree/bindings/iio/light/vishay,vcnl4000.yaml

2.23.0