diff --git a/Documentation/ABI/testing/sysfs-driver-lenovo-yb9-kbdock b/Documentation/ABI/testing/sysfs-driver-lenovo-yb9-kbdock new file mode 100644 index 000000000000..ebe713aefad1 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-driver-lenovo-yb9-kbdock @@ -0,0 +1,19 @@ +What: /sys/bus/wmi/drivers/lenovo-yb9-kbdock//keyboard_position +Date: June 2027 +KernelVersion: 7.3 +Contact: Dave Carey +Description: + Read-only attribute reporting the current keyboard dock position + as reported by the Embedded Controller on the Lenovo Yoga Book 9 + 14IAH10. + + Possible values: + + == ============================================================= + 0 keyboard is not docked to any screen (detached) + 1 keyboard docked on the top half of the bottom screen + 2 keyboard docked on the bottom half of the bottom screen + == ============================================================= + + SW_TABLET_MODE input events are also emitted: 0 when the keyboard + is docked (either position), 1 when detached. diff --git a/MAINTAINERS b/MAINTAINERS index 3820b286f09f..8abf559a138c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14710,6 +14710,13 @@ F: drivers/hid/hid-lenovo-go-s.c F: drivers/hid/hid-lenovo-go.c F: drivers/hid/hid-lenovo.c +LENOVO YOGA BOOK 9 KEYBOARD DOCK DRIVER +M: Dave Carey +L: platform-driver-x86@vger.kernel.org +S: Maintained +F: Documentation/ABI/testing/sysfs-driver-lenovo-yb9-kbdock +F: drivers/platform/x86/lenovo/yb9-kbdock.c + LETSKETCH HID TABLET DRIVER M: Hans de Goede L: linux-input@vger.kernel.org diff --git a/drivers/platform/x86/lenovo/Kconfig b/drivers/platform/x86/lenovo/Kconfig index 4443f40ef8aa..516594993073 100644 --- a/drivers/platform/x86/lenovo/Kconfig +++ b/drivers/platform/x86/lenovo/Kconfig @@ -43,6 +43,20 @@ config LENOVO_WMI_CAMERA To compile this driver as a module, choose M here: the module will be called lenovo-wmi-camera. +config LENOVO_YB9_KBDOCK + tristate "Lenovo Yoga Book 9 keyboard dock detection" + depends on ACPI_WMI + depends on DMI + depends on INPUT + help + Say Y here to enable keyboard dock detection on the Lenovo Yoga Book 9 + 14IAH10. The detachable Bluetooth keyboard magnetically attaches to + either screen; this driver reports SW_TABLET_MODE input events based + on the attachment state and exposes the raw position in sysfs. + + To compile this driver as a module, choose M here: the module will be + called lenovo-yb9-kbdock. + config LENOVO_YMC tristate "Lenovo Yoga Tablet Mode Control" depends on ACPI_WMI diff --git a/drivers/platform/x86/lenovo/Makefile b/drivers/platform/x86/lenovo/Makefile index 91a9370f11b3..12816d8d5e24 100644 --- a/drivers/platform/x86/lenovo/Makefile +++ b/drivers/platform/x86/lenovo/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_THINKPAD_LMI) += think-lmi.o obj-$(CONFIG_THINKPAD_ACPI) += thinkpad_acpi.o lenovo-target-$(CONFIG_LENOVO_WMI_HOTKEY_UTILITIES) += wmi-hotkey-utilities.o +lenovo-target-$(CONFIG_LENOVO_YB9_KBDOCK) += yb9-kbdock.o lenovo-target-$(CONFIG_LENOVO_YMC) += ymc.o lenovo-target-$(CONFIG_YOGABOOK) += yogabook.o lenovo-target-$(CONFIG_YT2_1380) += yoga-tab2-pro-1380-fastcharger.o diff --git a/drivers/platform/x86/lenovo/yb9-kbdock.c b/drivers/platform/x86/lenovo/yb9-kbdock.c new file mode 100644 index 000000000000..70d81f3af09e --- /dev/null +++ b/drivers/platform/x86/lenovo/yb9-kbdock.c @@ -0,0 +1,323 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Lenovo Yoga Book 9 keyboard-dock detection + * + * The Yoga Book 9 ships with a detachable Bluetooth keyboard that magnetically + * attaches to the bottom screen in one of two positions. The EC tracks + * attachment state in a 2-bit field called BKBD and signals changes via WMI + * event 0xEB on the WM10 ACPI device (_UID "GMZN"). + * + * BKBD values: + * 0 = keyboard detached + * 1 = keyboard docked on the top half of the bottom screen + * 2 = keyboard docked on the bottom half of the bottom screen + * 3 = reserved / not observed + * + * Two WMI interfaces are used (documented in embedded BMOF, WQDD, 20705 bytes): + * + * LENOVO_BTKBD_EVENT (event GUID, 806BD2A2-...) + * WmiDataId(1) uint32 Status — _WED(0xEB) returns EC.BKBD directly. + * The notify callback receives BKBD as an integer; no separate query needed. + * + * LENOVO_FEATURE_STATUS_DATA (block GUID, E7F300FA-...) + * WmiDataId(1) uint32 IDs = 0x00060000 (feature selector) + * WmiDataId(2) uint32 Status = BKBD value + * Used on probe and resume to read initial state. + * + * The event driver (LENOVO_BTKBD_EVENT) fires a notifier chain on each WMI + * event. The block driver (LENOVO_FEATURE_STATUS_DATA) owns the input_dev + * and registers a notifier_block to receive those events, eliminating the + * need for shared global state or a mutex. + * + * SW_TABLET_MODE=1 is reported when the keyboard is detached; + * SW_TABLET_MODE=0 when docked in either position (keyboard present). + * The raw BKBD value is exposed via the sysfs attribute "keyboard_position". + * + * Copyright (C) 2026 Dave Carey + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define YB9_KBDOCK_EVENT_GUID "806BD2A2-177B-481D-BFB5-3BA0BB4A2285" +#define YB9_KBDOCK_QUERY_GUID "E7F300FA-21CD-4003-ADAC-2696135982E6" + +/* BKBD encoding */ +#define BKBD_DETACHED 0 + +/* LENOVO_FEATURE_STATUS_DATA feature selector */ +#define YB9_FEATURE_STATUS_ID 0x00060000u + +/* + * LENOVO_FEATURE_STATUS_DATA: 8-byte buffer {uint32 IDs, uint32 Status}. + * IDs is always 0x00060000; Status holds the BKBD value (0–3). + */ +struct lenovo_feature_status { + __le32 id; + __le32 status; +} __packed; + +/* ------------------------------------------------------------------ + * Notifier chain — event driver fires it, block driver listens + * ------------------------------------------------------------------ */ + +static BLOCKING_NOTIFIER_HEAD(yb9_kbdock_chain_head); + +static void devm_yb9_kbdock_unregister_notifier(void *data) +{ + struct notifier_block *nb = data; + + blocking_notifier_chain_unregister(&yb9_kbdock_chain_head, nb); +} + +static int devm_yb9_kbdock_register_notifier(struct device *dev, + struct notifier_block *nb) +{ + int ret; + + ret = blocking_notifier_chain_register(&yb9_kbdock_chain_head, nb); + if (ret < 0) + return ret; + + return devm_add_action_or_reset(dev, devm_yb9_kbdock_unregister_notifier, nb); +} + +/* ------------------------------------------------------------------ + * Block WMI driver — LENOVO_FEATURE_STATUS_DATA + * (owns input_dev, sysfs, PM resume) + * ------------------------------------------------------------------ */ + +struct yb9_kbdock_data { + struct wmi_device *wdev; + struct input_dev *input_dev; + struct notifier_block nb; + spinlock_t lock; /* protects input_report_switch + input_sync */ +}; + +static int yb9_kbdock_query(struct yb9_kbdock_data *d, u32 *bkbd) +{ + struct wmi_buffer out; + int ret; + + ret = wmidev_query_block(d->wdev, 0, &out, + sizeof(struct lenovo_feature_status)); + if (ret) + return ret; + + struct lenovo_feature_status *fs __free(kfree) = out.data; + + if (le32_to_cpu(fs->id) != YB9_FEATURE_STATUS_ID) + return -EIO; + + *bkbd = le32_to_cpu(fs->status); + return 0; +} + +static void yb9_kbdock_report(struct yb9_kbdock_data *d, u32 bkbd) +{ + int tablet = (bkbd == BKBD_DETACHED) ? 1 : 0; + + spin_lock(&d->lock); + input_report_switch(d->input_dev, SW_TABLET_MODE, tablet); + input_sync(d->input_dev); + spin_unlock(&d->lock); + dev_dbg(&d->wdev->dev, "BKBD=%u SW_TABLET_MODE=%d\n", bkbd, tablet); +} + +static int yb9_kbdock_sync(struct yb9_kbdock_data *d) +{ + u32 bkbd; + int ret; + + ret = yb9_kbdock_query(d, &bkbd); + if (ret) + return ret; + + yb9_kbdock_report(d, bkbd); + return 0; +} + +static int yb9_kbdock_nb_call(struct notifier_block *nb, + unsigned long bkbd, void *unused) +{ + struct yb9_kbdock_data *d = + container_of(nb, struct yb9_kbdock_data, nb); + + yb9_kbdock_report(d, bkbd); + return NOTIFY_DONE; +} + +static ssize_t keyboard_position_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct yb9_kbdock_data *d = dev_get_drvdata(dev); + u32 bkbd; + int ret; + + ret = yb9_kbdock_query(d, &bkbd); + if (ret) + return ret; + return sysfs_emit(buf, "%u\n", bkbd); +} +static DEVICE_ATTR_RO(keyboard_position); + +static const struct attribute * const yb9_kbdock_attrs[] = { + &dev_attr_keyboard_position.attr, + NULL, +}; +ATTRIBUTE_GROUPS(yb9_kbdock); + +static int yb9_kbdock_resume(struct device *dev) +{ + struct yb9_kbdock_data *d = dev_get_drvdata(dev); + + return yb9_kbdock_sync(d); +} +static DEFINE_SIMPLE_DEV_PM_OPS(yb9_kbdock_pm_ops, NULL, yb9_kbdock_resume); + +static int yb9_kbdock_block_probe(struct wmi_device *wdev, const void *ctx) +{ + struct yb9_kbdock_data *d; + struct input_dev *input_dev; + int ret; + + d = devm_kzalloc(&wdev->dev, sizeof(*d), GFP_KERNEL); + if (!d) + return -ENOMEM; + + d->wdev = wdev; + spin_lock_init(&d->lock); + + input_dev = devm_input_allocate_device(&wdev->dev); + if (!input_dev) + return -ENOMEM; + + input_dev->name = "Lenovo Yoga Book 9 keyboard dock switch"; + input_dev->phys = YB9_KBDOCK_QUERY_GUID "/input0"; + input_dev->id.bustype = BUS_HOST; + input_set_capability(input_dev, EV_SW, SW_TABLET_MODE); + + ret = input_register_device(input_dev); + if (ret) + return ret; + + d->input_dev = input_dev; + d->nb.notifier_call = yb9_kbdock_nb_call; + + ret = devm_yb9_kbdock_register_notifier(&wdev->dev, &d->nb); + if (ret) + return ret; + + dev_set_drvdata(&wdev->dev, d); + return yb9_kbdock_sync(d); +} + +static const struct wmi_device_id yb9_kbdock_block_id_table[] = { + { .guid_string = YB9_KBDOCK_QUERY_GUID }, + { } +}; + +static struct wmi_driver yb9_kbdock_block_driver = { + .driver = { + .name = "lenovo-yb9-kbdock", + .dev_groups = yb9_kbdock_groups, + .pm = pm_sleep_ptr(&yb9_kbdock_pm_ops), + }, + .id_table = yb9_kbdock_block_id_table, + .no_singleton = true, + .probe = yb9_kbdock_block_probe, +}; + +/* ------------------------------------------------------------------ + * Event WMI driver — LENOVO_BTKBD_EVENT + * (fires the notifier chain on each WMI event) + * ------------------------------------------------------------------ */ + +static void yb9_kbdock_notify_new(struct wmi_device *wdev, + const struct wmi_buffer *data) +{ + /* + * _WED(0xEB) returns EC.BKBD directly as a 32-bit integer + * (LENOVO_BTKBD_EVENT WmiDataId(1) uint32 Status). + * Short-buffer guard is handled by .min_event_size below. + */ + u32 bkbd = le32_to_cpu(*(const __le32 *)data->data); + + blocking_notifier_call_chain(&yb9_kbdock_chain_head, bkbd, NULL); +} + +static const struct wmi_device_id yb9_kbdock_event_id_table[] = { + { .guid_string = YB9_KBDOCK_EVENT_GUID }, + { } +}; +MODULE_DEVICE_TABLE(wmi, yb9_kbdock_event_id_table); + +static struct wmi_driver yb9_kbdock_event_driver = { + .driver = { + .name = "lenovo-yb9-kbdock-event", + }, + .id_table = yb9_kbdock_event_id_table, + .no_singleton = true, + .notify_new = yb9_kbdock_notify_new, + .min_event_size = sizeof(__le32), +}; + +/* ------------------------------------------------------------------ + * Module init / exit + * ------------------------------------------------------------------ */ + +static const struct dmi_system_id yb9_kbdock_dmi_table[] __initconst = { + { + /* Lenovo Yoga Book 9 14IAH10 */ + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_NAME, "83KJ"), + }, + }, + { } +}; + +static int __init yb9_kbdock_init(void) +{ + int ret; + + if (!dmi_check_system(yb9_kbdock_dmi_table)) + return -ENODEV; + + ret = wmi_driver_register(&yb9_kbdock_event_driver); + if (ret) + return ret; + + ret = wmi_driver_register(&yb9_kbdock_block_driver); + if (ret) { + wmi_driver_unregister(&yb9_kbdock_event_driver); + return ret; + } + + return 0; +} +module_init(yb9_kbdock_init); + +static void __exit yb9_kbdock_exit(void) +{ + wmi_driver_unregister(&yb9_kbdock_block_driver); + wmi_driver_unregister(&yb9_kbdock_event_driver); +} +module_exit(yb9_kbdock_exit); + +MODULE_AUTHOR("Dave Carey "); +MODULE_DESCRIPTION("Lenovo Yoga Book 9 keyboard dock detection"); +MODULE_LICENSE("GPL");