SP11: add protocol-9 QSPI and OF-only MSHW0485 touch

[ooaklee]

Summary

• re-lift protocol-9 QSPI support onto the current 7.2.2 GPI and GENI SPI drivers
• add an OF-only direct-input driver and binding for the Surface Pro 11 MSHW0485 touchscreen
• add the Denali QSPI DMA/controller/touch nodes for both supported SP11 variants
• keep pen and every experimental userspace ABI out of this topic

Dependency and status

Review/merge after #82, the Denali DT baseline topic. This branch is nevertheless based directly on jg/ubuntu-qcom-x1e-7.2.y at 032e174490d2, so the shared-driver diff remains independently reviewable.

This is the release-line QSPI/touch extraction planned after the working staging correction in merged #81. It does not replay #81 or the staging branch's complete driver files. The PR remains a draft until this exact re-lift has been installed and tested on Surface Pro 11 hardware.

The default-off pen/HIDRAW/heat-frame work will follow as a separate, explicitly gated topic and is not present here.

Containment

• GPI changes activate only for QCOM_GPI_QSPI; the existing SPI, I2C, and UART protocols are unchanged
• GENI QSPI mode requires both the qcom,geni-qspi controller property and the microsoft,denali root compatible
• the touch driver binds only through OF compatible microsoft,mshw0485 and rejects non-Denali machines
• there is no ACPI match, SPI-ID fallback, module parameter, diagnostic sysfs attribute, misc device, HIDRAW endpoint, pen input, or /dev/g6ts-heat
• the direct-touch binding and nodes describe only the fixed power/reset/interrupt wiring used on Denali

The current release base already contains DMA_PRIVATE and the GENI SPI tracepoints. This series preserves them and creates no intentional diff for either facility.

Provenance

The series keeps original authors where the source has a valid author sign-off:

• x1e-nixos <noreply@scug.io> remains author of the QSPI DMA binding and current-tree GPI re-lift, derived from 19bed4c3b6c1
• the GENI SPI change is a substantial current-tree re-lift authored and signed by Leon, with source credit to 65ce06ca2b00 and the final staging behavior in b1075e60d0b1; the older SPI source has no author DCO trailer, so none was invented
• the direct touch core is a focused rewrite of the final phase55 behavior; the invalid placeholder author from that staging commit is not propagated
• Justin White remains author of the X1P product-ID follow-up from 3fc7c5249f4a, with his original author date and sign-off preserved

Leon signs each rewritten/submitted commit as Leon Silcott <leon@boasi.io>.

Validation

• git diff --check 032e174490d2..HEAD
• strict checkpatch in Linux with python3-ply: no errors or checks; only the generic new-file/MAINTAINERS prompt for the new binding and driver, both already covered by the existing INPUT (KEYBOARD, MOUSE, JOYSTICK, TOUCHSCREEN) DRIVERS entry
• strict checkpatch with only that accounted FILE_PATH_CHANGES warning suppressed: no errors, warnings, or checks
• ARM64 ubuntu_x1e_defconfig W=1 builds of drivers/dma/qcom/gpi.o, drivers/spi/spi-geni-qcom.o, and drivers/input/touchscreen/mshw0485_touch.o
• DT binding/schema validation and yamllint for the new/updated schemas
• qcom/x1e80100-microsoft-denali-oled.dtb builds and passes the selected checks
• qcom/x1p64100-microsoft-denali.dtb builds and passes the selected checks
• non-SP11 qcom/x1e80100-dell-xps13-9345.dtb builds successfully
• source audit confirms DMA_PRIVATE and all existing GENI tracepoints remain intact
• ABI audit confirms the touch core exposes none of the deferred pen/diagnostic interfaces

Hardware checks still required

• boot this exact branch on an X1E or X1P Surface Pro 11
• verify QSPI GPI descriptor mode and MSHW0485 initialization in the boot log
• verify multitouch input, suspend/resume, and repeated touch-controller resets
• verify a non-SP11 X1E system still boots with its normal GENI SPI/GPI paths; the Dell DTB build above is the available compile-time guard, not a hardware claim

[ooaklee]

Follow-up validation for the SP11 7.2.2 retrospective:

• This PR head is now 4c9324a851a8.
• The follow-up publishes the complete 64-bit Denali QSPI event-ring doorbell before channel activation; the completion workarounds remain scoped through microsoft,denali, in line with the PR SP11: integrate 7.2.x platform, IPTS pen, audio, camera, and power support #79 guardrail.
• The combined demonstration target (sp11/ubuntu-qcom-x1e-7.2.y-target, b807d9e52ac9) and retrospective branch (sp11/ubuntu-qcom-x1e-7.2.y-target-fix-pt-2, dd928de48c03) include this change.
• A clean Lexr container build from the pushed retrospective branch completed successfully as 7.2.2-jg-0sp11v2-qcom-x1e; both Denali DTBs and drivers/dma/qcom/gpi.ko.zst are present in the resulting bundle.

This is build/package validation. Touch and pen still require a physical boot/resume test on the Surface Pro 11.