[PATCH 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. The existing dw_i2c_amd_gpio_defer_dmi quirk for this
   hardware checks gpio_dev->driver which is set before probe finishes,
   so the deferral does not actually enforce ordering.

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

Patch 2 fixes the existing broken deferral in i2c-designware-platdrv to
use device_is_bound() under device_lock(), which correctly waits for
pinctrl-amd probe to complete before AMDI0010:02 is probed.

Both patches tested on Lenovo Yoga 7 14AGP11 (83TD), Fedora 44, kernel
7.1.0-rc2+. Touch and stylus fully functional after applying both patches.

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

Hardik Prakash (2):
  pinctrl-amd: enable IRQ for WACF2200 touchscreen on Lenovo Yoga 7
    14AGP11
  i2c: designware: fix probe ordering for AMD GPIO on Lenovo Yoga 7
    14AGP11

 drivers/i2c/busses/i2c-designware-platdrv.c | 81 +++++++++++++++++++++
 drivers/pinctrl/pinctrl-amd.c               | 35 +++++++++
 2 files changed, 116 insertions(+)

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2.54.0