[PATCH v2 0/2] Fix WACF2200 touchscreen on Lenovo Yoga 7 14AGP11

[Hardik Prakash <hardikprakash.official@gmail.com>]

The Wacom WACF2200 touchscreen on the Lenovo Yoga 7 14AGP11 (83TD) is
completely non-functional on Linux. The I2C bus (AMDI0010:02) fails with
repeated lost arbitration errors at boot before any driver can probe the
device. The touchscreen works correctly in UEFI and Windows.

Investigation using ACPI _CRS decode and Windows/Linux GPIO register
comparison identified two bugs:

1. GPIO 157 (WACF2200 GpioInt per ACPI _CRS) has INTERRUPT_ENABLE and
   INTERRUPT_MASK cleared by amd_gpio_irq_init() and never restored,
   preventing the device from signalling the driver. Windows keeps both
   bits set after initialisation.

2. i2c_designware probes AMDI0010:02 before pinctrl-amd's probe
   completes. A DMI-matched deferral is added to correctly enforce
   ordering using device_is_bound() under device_lock().

Patch 1 adds a DMI quirk in pinctrl-amd to restore GPIO 157 interrupt
bits after amd_gpio_irq_init().

Patch 2 adds a probe deferral in i2c-designware-platdrv that correctly
waits for pinctrl-amd to fully complete before AMDI0010:02 is probed,
using acpi_dev_get_first_match_dev() and acpi_get_first_physical_node()
for robust device lookup.

Both patches tested on Lenovo Yoga 7 14AGP11 (83TD), Fedora 44, kernel
7.1.0-rc2+. Touch and stylus fully functional across 4 stable reboots.

v2:
 - Patch 2: replace custom HID/UID lookup helpers with
   acpi_dev_get_first_match_dev() (Andy Shevchenko)
 - Patch 2: use acpi_get_first_physical_node() to get the platform
   device for correct device_is_bound() check
 - Patch 2: use device_is_bound() under device_lock() with explanatory
   comments (Andy Shevchenko)
 - Patch 2: fix dev_warn to use dev_name() instead of hardcoded suffix
   (Andy Shevchenko)
 - Patch 2: fix commit message (removed incorrect "existing" reference)
 - Both patches: add Assisted-by tags per coding-assistants.rst
 - Patch 1: no functional changes (Acked-by: Andy Shevchenko)

Kernel bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=221494
Related: https://bugzilla.kernel.org/show_bug.cgi?id=221454


 drivers/i2c/busses/i2c-designware-platdrv.c | 75 +++++++++++++++++++++
 drivers/pinctrl/pinctrl-amd.c               | 35 ++++++++++
 2 files changed, 110 insertions(+)

-- 
2.54.0