BFE Engineering
42fb386f60
Replace every em dash with real punctuation (rewrites, not hyphen swaps) in docs, code comments, scripts, configs, and the port records; convert en dashes, curly quotes, ellipsis glyphs, arrows, and section signs to ASCII; drop machine-writing tell phrases from living docs. ADR titles now use a colon. The M2 bring-up DTS model string carried an em dash into the patch series and its record echoes; fixed at both, and the full series re-verified to apply cleanly onto pristine 6.18.46. One comment in freshness.h deliberately names the em dash glyph the UI renders as the unknown mark; that is data, kept as prose naming it. Verified: cargo tests (sim, config-lint, rs485-bridge), shellcheck, both driver MC/DC harnesses, patches-apply.
2.4 KiB
GT911 capacitive touch: VERIFIED on warden-c8a3 (2026-08-25)
Touch works on our self-built 6.18.46 (_b): the WardenOS UI responds to
taps/swipes (confirmed by hand on the physical panel). Objective evidence:
Goodix-TS 3-0014: ID 911, version: 1060
input: Goodix Capacitive TouchScreen as .../i2c-3/3-0014/input/input0
/dev/input/event0 is created and held open by warden-ui (pid 517, exclusive
EVIOCGRAB: which is why a second reader sees 0 bytes; the events go to the UI).
Root cause on _b
Touch was dead on _b while fine on _a. dmesg showed:
module goodix: .gnu.linkonce.this_module section size must match the kernel's
built struct module size at run time
The stock rootfs ships goodix.ko built for the 5.10 kernel; it cannot load
on our 6.18 (struct module layout mismatch). Our 6.18 .config did not have
the driver at all (# CONFIG_TOUCHSCREEN_GOODIX is not set), and the DTS had no
GT911 node, so nothing drove the GT911.
Fix
CONFIG_TOUCHSCREEN_GOODIX=y: build the mainline Goodix driver into the kernel (no module -> no vermagic/struct mismatch; the stale rootfs.kostill fails to insmod but is now harmless).- GT911 DT node under
&i2c3(matches the vendor 86-panel wiring):plustouchscreen@14 { compatible = "goodix,gt911"; reg = <0x14>; interrupt-parent = <&gpio0>; interrupts = <RK_PA0 IRQ_TYPE_EDGE_FALLING>; irq-gpios = <&gpio0 RK_PA0 GPIO_ACTIVE_HIGH>; reset-gpios = <&gpio3 RK_PD0 GPIO_ACTIVE_HIGH>; };pinctrl-0 = <&i2c3m2_xfer &tp_rst &tp_irq>on&i2c3and thetp_rst(GPIO3_D0) /tp_irq(GPIO0_A0) pin groups.
Polarity note: mainline goodix drives reset logical 0 = hold, 1 = release, and
the GT911 reset is physically active-low, so reset-gpios is ACTIVE_HIGH
(logical==physical), NOT the ACTIVE_LOW the vendor 5.10 driver used. Confirmed
against mainline gt911 DT examples (sun7i-a20-wexler-tab7200 etc.): both irq-gpios
and reset-gpios are ACTIVE_HIGH; reg 0x14 needs irq-gpios for address select.
Non-fatal: Direct firmware load for goodix_911_cfg.bin failed (-2); the GT911
uses its flashed internal config; touch works without a cfg.bin.
Files changed (research/linux-6.18.46)
.config:CONFIG_TOUCHSCREEN_GOODIX=y.arch/arm/boot/dts/rockchip/rv1106-warden.dts: GT911 node on&i2c3,tp_rst/tp_irqpin groups under&pinctrl.