Re: [PATCH v2 0/5] iio: light: stk3310: per-chip match data and STK36C61 support

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 26 Aug 2026 19:54:04 +0200
Jorijn van der Graaf <jorijnvdgraaf@catcrafts.net> wrote:

> The Sensortek STK36C61 is a 3-in-1 ambient light / proximity / RGB
> colour sensor whose register interface is compatible with the stk3310
> across the ALS and proximity data, threshold, gain and
> integration-time registers this driver uses. The part name comes from
> the Fairphone 6 manual, which lists the component as "3IN1 ALPS/RGB
> sensor/STK36C61". There is no public datasheet; the layout was probed
> on the device: chip ID 0x95, the stk3310 STATE/FLAG bit layout, data
> and threshold registers, gain steps that scale the ALS reading
> accordingly, and an RGBC data block directly after the ALS data.
> 
> Since v1 the colour block's controls were located, confirming
> Jonathan's guess on v1's patch 3 that they sit in a register we had
> not found: the STK37660 datasheet, a documented sibling with the same
> data register layout, places a clear-channel gain field in a GAINCTRL
> register at 0x4E, split from the RGB gain in ALSCTRL, and stepping it
> on the STK36C61 multiplies the clear count by ~4 per step while the
> other channels hold still. The STK36C61 patch therefore now exposes
> scale and integration time on the colour channels.
> 
> Tested on a Fairphone 6 running a 7.2-based tree: this series'
> stk3310.c, byte-identical, built as a module against that tree (the
> i2c core files the binding behaviour depends on are identical between
> the trees). Verified there: DT boot instantiation, the colour
> scale/integration-time interface, and the sysfs name behaviours this
> series changes: a lower-case name selects the full profile through
> the id table, capitals no longer bind, and a full-compatible-string
> client now fails probe with the missing-driver-data error. A board
> DTS node using the new compatible follows separately via
> linux-arm-msm.
> 
> Changes in v2:
> - new first patch lower-casing the i2c device ID names (Andy), and
>   probe now fails on missing match data instead of falling back to
>   the stk3310 profile (Andy)
> - new precursor patch moving the data registers into the channel
>   .address field (Jonathan), split out of the match-data patch; the
>   bulk read gains a regmap local variable (Andy)
> - the ACPI table entries use named initializers (Jonathan)
> - the STK36C61 patch exposes scale and integration time on the colour
>   channels (Jonathan's suggestion on v1 patch 3; the clear-gain
>   register located via the STK37660 datasheet and verified on the
>   device). With those branches of read_raw now handling the intensity
>   channels, the ret = -EINVAL single-exit form promised on the v1
>   thread (Andy) has no unreachable branch left to apply to
> - picked up Krzysztof's Reviewed-by on the binding patch
> 
> v1: https://lore.kernel.org/all/20260810110423.41697-1-jorijnvdgraaf@catcrafts.net/
> 
FWIW I took another look through and with those small things Andy raised
tidied up (including a more concise commit message for the final patch) this
looks good to go to me.

Thanks,

Jonathan