9.1.2. Misc sensors (fingerprint, hall, keyboard cover)¶

The small peripherals that don’t carry enough register/protocol-level detail to earn their own page: the fingerprint sensor, the hall-effect cover switch, and the detachable keyboard cover’s connector pins. All are DT-bound and built into artifacts/kernel (DTBO overlays); none of them needed disassembly beyond confirming the binding. None of these are physical keys you press — the power/volume buttons are in Physical keys: power, volume, and the boot-mode dispatcher.

9.1.2.1. DT bindings¶

Device	`compatible`	Bus	GPIOs / notes
Fingerprint (`fragment@57`)	`fortsense,fortsense_fp` / `chipsailing_fp` / `microarray_fp`	SPI	three vendor drivers compiled in; the one whose chip answers is used (`cs-gpios`, `onyx,rst_gpio`, `onyx,irq_gpio`) — that selection-by-probe behavior is inferred from driver structure, not traced at runtime, see Fingerprint below. TA/firmware side: `fpchips64` in `/vendor/firmware` (Secure world and coprocessors (TZ, HYP, trustlets))
Hall sensor (`onyx_hall`)	onyx hall (`fragment@52`)	GPIO	`irq-gpio` — magnetic cover/case-close detection
Keyboard cover (`onyx-keyboard`)	`onyx,keyboard-ultra2`	—	`vcc-ctrl`, `id-gpio`, `id-gpio2`, `wake-gpio` — pogo-pin connector pins (presence/wake detection); the keyboard’s own keys are not something this DT node describes

The camera nodes (qcom,cam-sensor@*, qcom,eeprom@*) in the overlay are stock SM6350 reference-design entries with no populated sensor on this PCB — the same reference-base pattern as the DSI/AMOLED panel names (Display pipeline — DSI transport to the color e-ink TCON).

9.1.2.2. Fingerprint¶

Three vendor drivers are compiled in and DT-described (fortsense,fortsense_fp, chipsailing_fp, microarray_fp), all on SPI with cs-gpios + reset/irq GPIOs; the driver whose chip is physically present is inferred to bind (from the compiled-in-driver structure, not traced at runtime) — the same “compile every candidate, whichever chip answers wins” pattern as the pen/touch swappable suppliers (Wacom EMR pen digitizer driver, Capacitive touch (Parade pt_core)). The secure/enrolment side is handled off-CPU (the fpchips64 firmware in /vendor/firmware and the TZ path, Secure world and coprocessors (TZ, HYP, trustlets)).

9.1.2.3. Hall sensor¶

onyx_hall is a magnetic-field switch on an irq-gpio, used to detect the magnetic cover opening/closing (sleep/wake the panel). It reports a proximity/field state, not a press — not a key.

9.1.2.4. Keyboard cover¶

onyx,keyboard-ultra2 is the detachable pogo-pin keyboard cover, identified by id-gpio/id-gpio2 and woken via wake-gpio (kernel onyx_keyboard_connect path). This DT node only describes the connector pins — presence detection and wake — not the keyboard’s own individual keys, which this dump has no register/protocol-level visibility into. The power and volume buttons, which are physical keys, are documented in Physical keys: power, volume, and the boot-mode dispatcher.

9.1.2.5. Sensors and charger (documented elsewhere)¶

Sensors (IMU, ALS, etc.) run on the ADSP via the SSC/QMI stack (qcom,qmi-sensors); there is no separate SLPI core on this SM6350 build (ADSP and CDSP firmware).
Charger is the PM7250B qcom,qpnp-smb5 with the SMB1396/SMB1398 charge pumps (qcom,smb1396-div2-cp-master / -slave / smb1398-pre-regulator) for fast charging (PMIC reset timers, charging and reachability).

9.1.2.6. Provenance¶

Source:: artifacts/dtbo_a/overlay_0.dts (all compatible bindings, SPI/GPIO assignments).
Method:: device-tree reading only — none of these devices carried enough register/protocol content to warrant static disassembly beyond confirming the DT binding. No code executed.
Cross-refs:: Wacom EMR pen digitizer driver, Capacitive touch (Parade pt_core), Secure world and coprocessors (TZ, HYP, trustlets), ADSP and CDSP firmware, PMIC reset timers, charging and reachability, Physical keys: power, volume, and the boot-mode dispatcher, DTBO overlays.