[PATCH v4 1/1] Input: atkbd - Fix TUXEDO NB02 notebook keyboards

[PATCH v4 1/1] Input: atkbd - Fix TUXEDO NB02 notebook keyboards

[Werner Sembach]

Some notebooks send Super + Control + KEY_ZENKAKUHANKAKU¹ upon pressing the
touchpad toggle key.

It can be mapped to correctly touggle the touchpad purely in userspace with
these patches:

- https://gitlab.freedesktop.org/xkeyboard-config/xkeyboard-config/-/merge_requests/810
- https://invent.kde.org/plasma/kwin/-/merge_requests/7278
- https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/2873

But as you can see, this requires per desktop environment patches. GNOME already
has the correct mapping and KDE does with the patches above, but smaller ones
might also need patches.

As an alternative soltuion I also wanted to suggest this i8042 filter + virtual
input device.

v2: Coding style fixes
v3: Send F21 keypress via virtual input device instead of serio interrupts
v4: Add cover letter
    Fix copy paste error "GPL-2.0-only" to "GPL-2.0-or-later"
    Add missing Copyright lines

Werner Sembach (1):
  Input: atkbd - Fix TUXEDO NB02 notebook keyboards touchpad toggle key

 MAINTAINERS                                 |   6 ++
 drivers/platform/x86/Kconfig                |   2 +
 drivers/platform/x86/Makefile               |   3 +
 drivers/platform/x86/tuxedo/Kbuild          |   8 ++
 drivers/platform/x86/tuxedo/Kconfig         |   8 ++
 drivers/platform/x86/tuxedo/nb02/Kbuild     |   9 ++
 drivers/platform/x86/tuxedo/nb02/Kconfig    |  17 ++++
 drivers/platform/x86/tuxedo/nb02/platform.c | 107 ++++++++++++++++++++
 8 files changed, 160 insertions(+)
 create mode 100644 drivers/platform/x86/tuxedo/Kbuild
 create mode 100644 drivers/platform/x86/tuxedo/Kconfig
 create mode 100644 drivers/platform/x86/tuxedo/nb02/Kbuild
 create mode 100644 drivers/platform/x86/tuxedo/nb02/Kconfig
 create mode 100644 drivers/platform/x86/tuxedo/nb02/platform.c

-- 
2.43.0

[PATCH v4 1/1] Input: atkbd - Fix TUXEDO NB02 notebook keyboards touchpad toggle key

[Werner Sembach]

The TUXEDO NB02 notebook keyboards touchpad toggle key sends the PS/2
scancode sequence:
0xe0, 0x5b, // Super down
0x1d,       // Control down
0x76,       // KEY_ZENKAKUHANKAKU down
0xf6,       // KEY_ZENKAKUHANKAKU up
0x9d,       // Control up
0xe0, 0xdb  // Super up

This driver listens to the Control + Super + Hangaku/Zenkaku key sequence
to suppresses the Hangaku/Zenkaku keypress and sends a F21 keypress
afterwards to conform with established userspace defaults. Note that the
Hangaku/Zenkaku scancode used here is usually unused, with real
Hangaku/Zenkaku keys using the tilde scancode.

Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
---
 MAINTAINERS                                 |   6 ++
 drivers/platform/x86/Kconfig                |   2 +
 drivers/platform/x86/Makefile               |   3 +
 drivers/platform/x86/tuxedo/Kbuild          |   8 ++
 drivers/platform/x86/tuxedo/Kconfig         |   8 ++
 drivers/platform/x86/tuxedo/nb02/Kbuild     |   9 ++
 drivers/platform/x86/tuxedo/nb02/Kconfig    |  17 ++++
 drivers/platform/x86/tuxedo/nb02/platform.c | 107 ++++++++++++++++++++
 8 files changed, 160 insertions(+)
 create mode 100644 drivers/platform/x86/tuxedo/Kbuild
 create mode 100644 drivers/platform/x86/tuxedo/Kconfig
 create mode 100644 drivers/platform/x86/tuxedo/nb02/Kbuild
 create mode 100644 drivers/platform/x86/tuxedo/nb02/Kconfig
 create mode 100644 drivers/platform/x86/tuxedo/nb02/platform.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 8e0736dc2ee0e..7139c32e96dc7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -24190,6 +24190,12 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux.git turbostat
 F:	tools/power/x86/turbostat/
 F:	tools/testing/selftests/turbostat/
 
+TUXEDO DRIVERS
+M:	Werner Sembach <wse@tuxedocomputers.com>
+L:	platform-driver-x86@vger.kernel.org
+S:	Supported
+F:	drivers/platform/x86/tuxedo/
+
 TW5864 VIDEO4LINUX DRIVER
 M:	Bluecherry Maintainers <maintainers@bluecherrydvr.com>
 M:	Andrey Utkin <andrey.utkin@corp.bluecherry.net>
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 0258dd879d64b..9b78a1255c08e 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -1199,3 +1199,5 @@ config P2SB
 	  The main purpose of this library is to unhide P2SB device in case
 	  firmware kept it hidden on some platforms in order to access devices
 	  behind it.
+
+source "drivers/platform/x86/tuxedo/Kconfig"
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index e1b1429470674..1562dcd7ad9a5 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -153,3 +153,6 @@ obj-$(CONFIG_WINMATE_FM07_KEYS)		+= winmate-fm07-keys.o
 
 # SEL
 obj-$(CONFIG_SEL3350_PLATFORM)		+= sel3350-platform.o
+
+# TUXEDO
+obj-y					+= tuxedo/
diff --git a/drivers/platform/x86/tuxedo/Kbuild b/drivers/platform/x86/tuxedo/Kbuild
new file mode 100644
index 0000000000000..1c79b80744d1b
--- /dev/null
+++ b/drivers/platform/x86/tuxedo/Kbuild
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2025 Werner Sembach wse@tuxedocomputers.com
+#
+# TUXEDO X86 Platform Specific Drivers
+#
+
+obj-y	+= nb02/
diff --git a/drivers/platform/x86/tuxedo/Kconfig b/drivers/platform/x86/tuxedo/Kconfig
new file mode 100644
index 0000000000000..13b484999e333
--- /dev/null
+++ b/drivers/platform/x86/tuxedo/Kconfig
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2025 Werner Sembach wse@tuxedocomputers.com
+#
+# TUXEDO X86 Platform Specific Drivers
+#
+
+source "drivers/platform/x86/tuxedo/nb02/Kconfig"
diff --git a/drivers/platform/x86/tuxedo/nb02/Kbuild b/drivers/platform/x86/tuxedo/nb02/Kbuild
new file mode 100644
index 0000000000000..f56629c8b9dd8
--- /dev/null
+++ b/drivers/platform/x86/tuxedo/nb02/Kbuild
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2025 Werner Sembach wse@tuxedocomputers.com
+#
+# TUXEDO X86 Platform Specific Drivers
+#
+
+tuxedo_nb02_platform-y			:= platform.o
+obj-$(CONFIG_TUXEDO_NB02_PLATFORM)	+= tuxedo_nb02_platform.o
diff --git a/drivers/platform/x86/tuxedo/nb02/Kconfig b/drivers/platform/x86/tuxedo/nb02/Kconfig
new file mode 100644
index 0000000000000..38cd60c9d4f03
--- /dev/null
+++ b/drivers/platform/x86/tuxedo/nb02/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2025 Werner Sembach wse@tuxedocomputers.com
+#
+# TUXEDO X86 Platform Specific Drivers
+#
+
+menuconfig TUXEDO_NB02_PLATFORM
+	tristate "TUXEDO NB02 Platform Driver"
+	help
+	  This driver implements miscellaneous things found on TUXEDO Notebooks
+	  with board vendor NB02. For the time being this is only remapping the
+	  touchpad toggle key to something supported by most Linux distros
+	  out-of-the-box and suppressing an unsupported scancode from the
+	  FN-key.
+
+	  When compiled as a module it will be called tuxedo_nb02_platform.
diff --git a/drivers/platform/x86/tuxedo/nb02/platform.c b/drivers/platform/x86/tuxedo/nb02/platform.c
new file mode 100644
index 0000000000000..da67a91a4a129
--- /dev/null
+++ b/drivers/platform/x86/tuxedo/nb02/platform.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2025 Werner Sembach wse@tuxedocomputers.com
+ */
+
+#include <linux/cleanup.h>
+#include <linux/container_of.h>
+#include <linux/dmi.h>
+#include <linux/i8042.h>
+#include <linux/input.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/serio.h>
+
+struct input_dev *idev;
+
+static void tux_nb02_f21(struct work_struct *work __always_unused)
+{
+	input_report_key(idev, KEY_F21, 1);
+	input_report_key(idev, KEY_F21, 0);
+	input_sync(idev);
+}
+DECLARE_WORK(tux_nb02_f21_work, tux_nb02_f21);
+
+static const u8 tux_nb02_touchp_toggle_seq[] = {
+	0xe0, 0x5b, // Super down
+	0x1d,       // Control down
+	0x76,       // KEY_ZENKAKUHANKAKU down
+	0xf6,       // KEY_ZENKAKUHANKAKU up
+	0x9d,       // Control up
+	0xe0, 0xdb  // Super up
+};
+
+static bool tux_nb02_i8042_filter(unsigned char data,
+				  unsigned char str,
+				  struct serio *port __always_unused,
+				  void *context __always_unused)
+{
+	static u8 seq_pos;
+
+	if (unlikely(str & I8042_STR_AUXDATA))
+		return false;
+
+	if (unlikely(data == tux_nb02_touchp_toggle_seq[seq_pos])) {
+		++seq_pos;
+		if (unlikely(data == 0x76 || data == 0xf6)) {
+			return true;
+		} else if (unlikely(seq_pos == ARRAY_SIZE(tux_nb02_touchp_toggle_seq))) {
+			schedule_work(&tux_nb02_f21_work);
+			seq_pos = 0;
+		}
+		return false;
+	}
+
+	seq_pos = 0;
+	return false;
+}
+
+static const struct dmi_system_id tux_nb02_dmi_string_match[] __initconst = {
+	{
+		.matches = {
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
+			DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "NB02"),
+		},
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(dmi, tux_nb02_dmi_string_match);
+
+static int __init tux_nb02_plat_init(void)
+{
+	int ret;
+
+	if (!dmi_check_system(tux_nb02_dmi_string_match))
+		return -ENODEV;
+
+	idev = input_allocate_device();
+	if (!idev)
+		return -ENOMEM;
+
+	idev->name = "TUXEDO NB02 Platform Keyboard";
+	set_bit(EV_KEY, idev->evbit);
+	set_bit(KEY_F21, idev->keybit);
+
+	ret = input_register_device(idev);
+	if (ret) {
+		input_free_device(idev);
+		return ret;
+	}
+
+	i8042_install_filter(tux_nb02_i8042_filter, NULL);
+
+	return 0;
+}
+
+static void __exit tux_nb02_plat_exit(void)
+{
+	i8042_remove_filter(tux_nb02_i8042_filter);
+	input_unregister_device(idev);
+}
+
+module_init(tux_nb02_plat_init);
+module_exit(tux_nb02_plat_exit);
+
+MODULE_DESCRIPTION("Keyboard fix for TUXEDO NB02 devices");
+MODULE_AUTHOR("Werner Sembach <wse@tuxedocomputers.com>");
+MODULE_LICENSE("GPL");
-- 
2.43.0