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bfe-core1106-sdk/kernel/rv1106-enablement/touch/VERIFIED.md
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BFE EngineeringandClaude Fable 5 5155224594 public-readiness: scrub internal details, split licensing, hosted kernel-build
Preparing the repo to go public (ADR-0007):

- CI: kernel-build moves from the self-hosted runner to ubuntu-latest
  (installs its own cross toolchain + qemu, caches the pristine tarball).
  On a public repo a registered self-hosted runner is reachable from
  approved fork-PR workflows — i.e. arbitrary code on private
  infrastructure — and the build never actually needed the SDK host.
  ADR-0004 marked superseded-in-part; docs/ci-cd.md rewritten (site
  specifics now live only in the private deployment log).
- Licensing: LICENSE gains the GPL-2.0 carve-out for patches/ and the
  kernel source excerpts (Linux derivatives; per-driver provenance was
  already tracked in PROVENANCE.md); patches/README.md states it too.
- Scrubbed from the tip: bench-unit dev credentials and its gadget IP
  (m2-boot notes), the site AP SSID+BSSID and a neighboring AP's BSSID
  and the device WLAN MAC (wifi bring-up evidence — BSSIDs are
  geolocatable), the runner mesh IP. NOTE: these remain in git history;
  decision on a pre-publication history rewrite is separate.
- Emoji cleanup across 21 tracked files (kernel port docs, review report,
  enforce-mcdc.sh) per repo text conventions: status marks became
  [x]/[wip]/[ ]/OK plain text.
- "[maintainer]-gated" process phrasing normalized to "maintainer-gated"
  (attributions in dated evidence docs kept).

Verified: zero emojis tracked; scrub grep clean; patches carry no internal
references; ci.yml parses; shellcheck unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018HUayid7W5w7jBdb9Rrj1K
2026-08-30 07:25:57 -06:00

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 ([maintainer] confirmed 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

  1. CONFIG_TOUCHSCREEN_GOODIX=y — build the mainline Goodix driver into the kernel (no module → no vermagic/struct mismatch; the stale rootfs .ko still fails to insmod but is now harmless).
  2. GT911 DT node under &i2c3 (matches the vendor 86-panel wiring):
    touchscreen@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>;
    };
    
    plus pinctrl-0 = <&i2c3m2_xfer &tp_rst &tp_irq> on &i2c3 and the tp_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)

  • .configCONFIG_TOUCHSCREEN_GOODIX=y.
  • arch/arm/boot/dts/rockchip/rv1106-warden.dts — GT911 node on &i2c3, tp_rst/tp_irq pin groups under &pinctrl.