[PATCH v3 0/4] HID: asus: Add Fn+F5 fan control key support for ROG laptops

["Ionut Nechita (Sunlight Linux)" <sunlightlinux@gmail.com>]

From: Ionut Nechita <ionut_n2001@yahoo.com>

This series adds support for the Fn+F5 fan control key on Asus ROG
laptops and addresses spurious HID vendor codes that cause kernel log
spam on these devices.

The series introduces:
1. Code cleanup by replacing a magic number with an existing constant
2. Filtering of spurious HID vendor usage codes on ROG laptops
3. Infrastructure for HID-to-WMI communication with proper build guards
4. Fn+F5 fan control key handler with userspace fallback support

The Fn+F5 key handler attempts to forward events to asus-wmi when
available. If asus-wmi is unavailable or fails, the event is passed
to userspace via evdev, allowing userspace fan control implementations.

Tested on Asus ROG series laptops.

Changes in v3:
- Added IS_REACHABLE(CONFIG_ASUS_WMI) conditional compilation guards
  to prevent build failures when asus-wmi is not compiled (patch 3)
- Modified Fn+F5 handler to pass events to userspace when asus-wmi is
  unavailable or fails, enabling userspace fan control (patch 4)
- Updated comments and commit message to reflect that spurious codes
  affect all ROG laptops, not just G14/G15, and occur during normal
  operation, not just on keypresses (patch 2)
- Simplified commit message for WMI infrastructure patch (patch 3)
- Added Reviewed-by tag from Denis Benato
- Removed Change-Id tags

Changes in v2:
- Split the original patch into a logical series of 4 patches
- Improved code organization and commit messages

Ionut Nechita (4):
  HID: asus: Replace magic number with HID_UP_ASUSVENDOR constant
  HID: asus: Filter spurious HID vendor codes on ROG laptops
  HID: asus: Add WMI communication infrastructure
  HID: asus: Implement Fn+F5 fan control key handler

 drivers/hid/hid-asus.c                     | 80 +++++++++++++++++++++-
 include/linux/platform_data/x86/asus-wmi.h |  1 +
 2 files changed, 80 insertions(+), 1 deletion(-)

--
2.52.0