On Fri, 5 Jul 2024 13:54:12 +0300 Matti Vaittinen <mazziesaccount@xxxxxxxxx> wrote: > The BU27034NUC was cancelled before it entered mass production. It was > replaced by a new variant BU27034ANUC (note, added 'A'). The new > variant gained a few significant changes, like removal of the 3.rd data > channel and dropping some of the gain settings. This means that, from > software point of view these ICs are incompatible. Lux calculation based > on the data from the sensors needs to be done differently, and on the > BU27034ANUC the channel 3 data is missing. Also, the gain setting > differencies matter. > > Unfortunately, the identification register was not changed so there is no > safe way for the software to distinguish the variants. > > According to the ROHM HQ engineers, the old BU27034NUC should not be > encountered in the wild. Hence it makes sense to remove the support for > the old BU27034NUC and add support for the new BU27034ANUC. Change the > compatible in order to not load the incompatible old driver for new sensor > (or, if someone had the old sensor, the new driver for it). > > Drop the compatible for old sensor which should not be in the wild and > add a new compatible for the new model with accurate model suffix > 'anuc'. > > Signed-off-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx> Rename indeed makes sense. One minor, 'whilst you are here' comment inline. > > --- > A patch renaming the file according to the new compatible will follow. > If renaming is not needed or appropriate, that patch can be dropped. > > Revision history: > v2: New patch > --- > .../devicetree/bindings/iio/light/rohm,bu27034.yaml | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/Documentation/devicetree/bindings/iio/light/rohm,bu27034.yaml b/Documentation/devicetree/bindings/iio/light/rohm,bu27034.yaml > index 30a109a1bf3b..535bd18348ac 100644 > --- a/Documentation/devicetree/bindings/iio/light/rohm,bu27034.yaml > +++ b/Documentation/devicetree/bindings/iio/light/rohm,bu27034.yaml > @@ -4,20 +4,19 @@ > $id: http://devicetree.org/schemas/iio/light/rohm,bu27034.yaml# > $schema: http://devicetree.org/meta-schemas/core.yaml# > > -title: ROHM BU27034 ambient light sensor > +title: ROHM BU27034ANUC ambient light sensor > > maintainers: > - Matti Vaittinen <mazziesaccount@xxxxxxxxx> > > description: | > - ROHM BU27034 is an ambient light sesnor with 3 channels and 3 photo diodes > + ROHM BU27034ANUC is an ambient light sesnor with 2 channels and 2 photo diodes sensor > capable of detecting a very wide range of illuminance. Typical application > is adjusting LCD and backlight power of TVs and mobile phones. > - https://fscdn.rohm.com/en/products/databook/datasheet/ic/sensor/light/bu27034nuc-e.pdf > > properties: > compatible: > - const: rohm,bu27034 > + const: rohm,bu27034anuc > > reg: > maxItems: 1 > @@ -37,7 +36,7 @@ examples: > #size-cells = <0>; > > light-sensor@38 { > - compatible = "rohm,bu27034"; > + compatible = "rohm,bu27034anuc"; > reg = <0x38>; > vdd-supply = <&vdd>; > };
