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". The layout was probed on the device: chip ID 0x95, the stk3310 STATE/FLAG bit layout, data and threshold registers (thresholds written through the event interface read back from the chip, and the FLAG near/far bit crosses with them), gain and integration-time fields the ALS and proximity readings scale with, and an RGBC data block directly after the ALS data, the red, green and blue assignments each confirmed by the matching channel dominating under the matching illumination and clear by its broadband response.
The colour controls: R, G and B share the illuminance channel's gain. Clear is gained by its own field in a GAINCTRL register at 0x4E, originally located via the datasheet of the STK37660 (a documented sibling with the same data register layout) and verified on the device: stepping it multiplies the clear count by ~4 per step while the other channels hold still. The STK36C61 patch exposes scale and integration time on the colour channels. A public datasheet exists: the STK36C61-A preliminary datasheet, version 0.9, hosted by LCSC [1]. It agrees with the device on the colour-engine layout (RGBC data at 0x15-0x1C, the clear gain in GAINCTRL 0x4E, the shared RGB-gain and integration-time fields in ALSCTRL1), but it documents the -A variant and gives the product ID as 0x93 where this part reports 0x95. Luca Weiss reports a newer revision (0.9.2) gives 0x95 and different mLux-per-count figures for the ALSCTRL1 gain settings. I could not find a published copy of that revision. 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 reaches the id table's match data, 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. Patch 5 carries no Datasheet: tag since the sheet at [1] is a preliminary for the -A variant: the published revision's product ID mismatches this part's, the register map omits the ALS data registers, and the later revision disagrees on the mLux-per-count figures. I am unable to find specifics for the Datasheet: tag, whether it must be the exact sheet for the part or if a "good enough" sheet is accepted. Changes in v3: - patch 4: drop the tab alignment of the chip_info members, take the probe failure through a struct device local, and return -ENODATA instead of -ENODEV on missing match data, commit message wording tightened (Andy) - patch 5: commit message squeezed to the point, the verification and colour-assignment detail moved into this letter, the scale rationale trimmed to its load-bearing constraint (Andy, Jonathan) - cover letter: the "no public datasheet" claim corrected (Marcelo) - picked up Andy's Reviewed-by on patches 1 and 3 v2: https://lore.kernel.org/all/[email protected]/ v1: https://lore.kernel.org/all/[email protected]/ [1] https://www.lcsc.com/datasheet/C49230205.pdf Assisted-by: Claude:claude-fable-5 Signed-off-by: Jorijn van der Graaf <[email protected]> Jorijn van der Graaf (5): iio: light: stk3310: lower-case the i2c device ID names dt-bindings: iio: light: stk33xx: document the Sensortek STK36C61 iio: light: stk3310: move the data registers into the channel address iio: light: stk3310: add per-chip match data iio: light: stk3310: support the Sensortek STK36C61 Documentation/ABI/testing/sysfs-bus-iio | 1 + .../bindings/iio/light/stk33xx.yaml | 9 +- drivers/iio/light/stk3310.c | 203 +++++++++++++----- 3 files changed, 156 insertions(+), 57 deletions(-) base-commit: 350d1fb9204b13c5f95e511e98b8bcb47574d425 -- 2.55.0
