0007-Add-IdeaPad-Usage-Mode-driver.patch

From eb9e6a8c9a65fd7b47034722ca07f39c7487e8f9 Mon Sep 17 00:00:00 2001
From: Philipp Jungkamp <p.jungkamp@gmx.net>
Date: Sat, 30 Jul 2022 15:46:13 +0200
Subject: [PATCH 7/8] Add IdeaPad Usage Mode driver

The so called 'usage mode' reported by the firmware of the Lenovo Yoga
line via ACPI WMI is mapped to a tablet mode switch input device.

Signed-off-by: Philipp Jungkamp <p.jungkamp@gmx.net>
---
 drivers/platform/x86/Kconfig                  |  11 +
 drivers/platform/x86/Makefile                 |   1 +
 drivers/platform/x86/ideapad-wmi-usage-mode.c | 279 ++++++++++++++++++
 3 files changed, 291 insertions(+)
 create mode 100644 drivers/platform/x86/ideapad-wmi-usage-mode.c

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index f2f98e942cf2..3e4f9ff4d7b7 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -140,6 +140,17 @@ config YOGABOOK_WMI
 	  To compile this driver as a module, choose M here: the module will
 	  be called lenovo-yogabook-wmi.
 
+config IDEAPAD_WMI_USAGE_MODE
+	tristate "Lenovo IdeaPad WMI usage mode"
+	depends on ACPI_WMI
+	depends on INPUT
+	help
+	  Say Y here if you want to receive SW_TABLET_MODE events depending on
+	  the usage mode (Laptop/Tent/Tablet/Drawboard) of the device.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called ideapad-wmi-usage-mode.
+
 config ACERHDF
 	tristate "Acer Aspire One temperature and fan driver"
 	depends on ACPI && THERMAL
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 5a428caa654a..a9f5009e4a3b 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_PEAQ_WMI)			+= peaq-wmi.o
 obj-$(CONFIG_XIAOMI_WMI)		+= xiaomi-wmi.o
 obj-$(CONFIG_GIGABYTE_WMI)		+= gigabyte-wmi.o
 obj-$(CONFIG_YOGABOOK_WMI)		+= lenovo-yogabook-wmi.o
+obj-$(CONFIG_IDEAPAD_WMI_USAGE_MODE)	+= ideapad-wmi-usage-mode.o
 
 # Acer
 obj-$(CONFIG_ACERHDF)		+= acerhdf.o
diff --git a/drivers/platform/x86/ideapad-wmi-usage-mode.c b/drivers/platform/x86/ideapad-wmi-usage-mode.c
new file mode 100644
index 000000000000..23d090c34d61
--- /dev/null
+++ b/drivers/platform/x86/ideapad-wmi-usage-mode.c
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Ideapad WMI usage mode driver
+ *
+ * Maps the usage mode reported by the Lenovo Yoga firmware to a
+ * tablet mode switch.
+ *
+ * Copyright (C) 2022 Philipp Jungkamp <p.jungkamp@gmx.net>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/acpi.h>
+#include <linux/input.h>
+#include <linux/input/sparse-keymap.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm.h>
+#include <linux/wmi.h>
+
+#define IDEAPAD_USAGE_MODE_EVENT_GUID	"06129D99-6083-4164-81AD-F092F9D773A6"
+#define IDEAPAD_USAGE_MODE_QUERY_GUID	"09B0EE6E-C3FD-4243-8DA1-7911FF80BB8C"
+
+enum ideapad_wmi_type {
+	IDEAPAD_WMI_USAGE_MODE_EVENT,
+	IDEAPAD_WMI_USAGE_MODE_QUERY,
+};
+
+struct ideapad_wmi_shared {
+	struct mutex *mutex;
+	struct wmi_device *event;
+	struct wmi_device *query;
+	struct input_dev *input_dev;
+};
+
+struct ideapad_wmi_private {
+	enum ideapad_wmi_type type;
+	struct ideapad_wmi_shared *shared;
+};
+
+static const struct key_entry ideapad_wmi_usage_mode_keymap[] = {
+	/* Laptop usage mode */
+	{ KE_SW, 0x01, { .sw = { SW_TABLET_MODE, 0 } } },
+	/* Tablet usage mode */
+	{ KE_SW, 0x02, { .sw = { SW_TABLET_MODE, 1 } } },
+	/* Drawing Board usage mode */
+	{ KE_SW, 0x03, { .sw = { SW_TABLET_MODE, 1 } } },
+	/* Tent usage mode */
+	{ KE_SW, 0x04, { .sw = { SW_TABLET_MODE, 1 } } },
+	{ KE_END },
+};
+
+static void ideapad_wmi_input_report(struct ideapad_wmi_private *priv,
+				     unsigned int scancode)
+{
+	dev_dbg(&priv->shared->query->dev,
+		"WMI report scancode: %d\n", scancode);
+	sparse_keymap_report_event(priv->shared->input_dev, scancode, 0 /* ignored */, true);
+}
+
+static void ideapad_wmi_update_usage_mode(struct ideapad_wmi_private *priv)
+{
+	struct wmi_device *query = priv->shared->query;
+	union acpi_object *obj;
+	struct acpi_buffer input;
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+	int ret;
+
+	input.length =  (acpi_size) 0;
+	input.pointer = NULL;
+
+	if (!query)
+		return;
+
+	ret = wmidev_evaluate_method(query, 0, 0, &input, &output);
+	if (ret) {
+		dev_warn(&query->dev,
+			"WMI query usage mode failed\n");
+		return;
+	}
+
+	obj = (union acpi_object *)output.pointer;
+
+	if (obj && obj->type == ACPI_TYPE_INTEGER)
+		ideapad_wmi_input_report(priv, obj->integer.value);
+	else
+		dev_warn(&query->dev,
+			"WMI query usage mode is not an integer\n");
+
+	kfree(output.pointer);
+}
+
+static int ideapad_wmi_shared_init(struct ideapad_wmi_private *priv,
+				   struct wmi_device *dev)
+{
+	struct ideapad_wmi_shared *shared = priv->shared;
+	struct input_dev *input_dev;
+	int err;
+
+	mutex_lock(shared->mutex);
+
+	switch (priv->type) {
+	case IDEAPAD_WMI_USAGE_MODE_EVENT:
+		shared->event = dev;
+		break;
+	case IDEAPAD_WMI_USAGE_MODE_QUERY:
+		shared->query = dev;
+		break;
+	}
+
+	if (!shared->event || !shared->query)
+		goto unlock;
+
+	input_dev = input_allocate_device();
+	if (!input_dev) {
+		err = -ENOMEM;
+		goto err_unlock;
+	}
+
+	input_dev->name = "IdeaPad WMI tablet mode switch";
+	input_dev->phys = IDEAPAD_USAGE_MODE_EVENT_GUID "/input0";
+	input_dev->id.bustype = BUS_HOST;
+	input_dev->dev.parent = &shared->event->dev;
+
+	err = sparse_keymap_setup(input_dev, ideapad_wmi_usage_mode_keymap, NULL);
+	if (err) {
+		dev_err(&shared->event->dev,
+			"Could not set up input device keymap: %d\n", err);
+		goto err_free_dev;
+	}
+
+	err = input_register_device(input_dev);
+	if (err) {
+		dev_err(&shared->event->dev,
+			"Could not register input device: %d\n", err);
+		goto err_free_dev;
+	}
+
+	shared->input_dev = input_dev;
+
+	ideapad_wmi_update_usage_mode(priv);
+unlock:
+	mutex_unlock(shared->mutex);
+	return 0;
+
+err_free_dev:
+	input_free_device(input_dev);
+err_unlock:
+	mutex_unlock(shared->mutex);
+	return err;
+}
+
+static void ideapad_wmi_shared_exit(struct ideapad_wmi_private *priv)
+{
+	struct ideapad_wmi_shared *shared = priv->shared;
+
+	mutex_lock(shared->mutex);
+
+	switch (priv->type) {
+	case IDEAPAD_WMI_USAGE_MODE_EVENT:
+		shared->event = NULL;
+		break;
+	case IDEAPAD_WMI_USAGE_MODE_QUERY:
+		shared->query = NULL;
+		break;
+	}
+
+	if (!shared->query && !shared->event) {
+		input_unregister_device(shared->input_dev);
+		shared->input_dev = NULL;
+	}
+
+	mutex_unlock(shared->mutex);
+}
+
+static int ideapad_wmi_probe(struct wmi_device *wdev, const void *ctx)
+{
+	const struct ideapad_wmi_private *context = ctx;
+	struct ideapad_wmi_private *priv;
+	int err;
+
+	priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->type = context->type;
+	priv->shared = context->shared;
+
+	err = ideapad_wmi_shared_init(priv, wdev);
+	if (err)
+		return err;
+
+	dev_set_drvdata(&wdev->dev, priv);
+
+	return 0;
+}
+
+static void ideapad_wmi_remove(struct wmi_device *wdev)
+{
+	struct ideapad_wmi_private *priv = dev_get_drvdata(&wdev->dev);
+
+	ideapad_wmi_shared_exit(priv);
+}
+
+static void ideapad_wmi_notify(struct wmi_device *wdev, union acpi_object *data)
+{
+	struct ideapad_wmi_private *priv = dev_get_drvdata(&wdev->dev);
+
+	dev_dbg(&priv->shared->query->dev,
+		"WMI notify\n");
+
+	ideapad_wmi_update_usage_mode(priv);
+}
+
+#ifdef CONFIG_PM_SLEEP
+#define ideapad_wmi_suspend 	NULL
+
+static int ideapad_wmi_resume(struct device *dev) {
+	struct ideapad_wmi_private *priv = dev_get_drvdata(dev);
+
+	ideapad_wmi_update_usage_mode(priv);
+
+	return 0;
+}
+
+#else
+#define ideapad_wmi_suspend 	NULL
+#define ideapad_wmi_resume 	NULL
+#endif
+
+static SIMPLE_DEV_PM_OPS(ideapad_wmi_pm, ideapad_wmi_suspend, ideapad_wmi_resume);
+
+static DEFINE_MUTEX(ideapad_wmi_shared_mutex);
+
+static struct ideapad_wmi_shared ideapad_wmi_shared = {
+	.mutex = &ideapad_wmi_shared_mutex,
+};
+
+static const struct ideapad_wmi_private ideapad_wmi_event_context = {
+	.type = IDEAPAD_WMI_USAGE_MODE_EVENT,
+	.shared = &ideapad_wmi_shared,
+};
+
+static const struct ideapad_wmi_private ideapad_wmi_query_context = {
+	.type = IDEAPAD_WMI_USAGE_MODE_QUERY,
+	.shared = &ideapad_wmi_shared,
+};
+
+static const struct wmi_device_id ideapad_wmi_id_table[] = {
+	{	/* Usage mode change event */
+		.guid_string = IDEAPAD_USAGE_MODE_EVENT_GUID,
+		.context = &ideapad_wmi_event_context,
+	},
+	{	/* Usage mode query method */
+		.guid_string = IDEAPAD_USAGE_MODE_QUERY_GUID,
+		.context = &ideapad_wmi_query_context,
+	},
+	{ }
+};
+
+static struct wmi_driver ideapad_wmi_driver = {
+	.driver = {
+		.name = "ideapad-wmi-usage-mode",
+		.pm = &ideapad_wmi_pm,
+	},
+	.no_notify_data = true,
+	.id_table = ideapad_wmi_id_table,
+	.probe = ideapad_wmi_probe,
+	.remove = ideapad_wmi_remove,
+	.notify = ideapad_wmi_notify,
+};
+
+module_wmi_driver(ideapad_wmi_driver);
+
+MODULE_DEVICE_TABLE(wmi, ideapad_wmi_id_table);
+MODULE_AUTHOR("Philipp Jungkamp <philipp.jungkamp@gmx.net>");
+MODULE_DESCRIPTION("Ideapad WMI usage mode driver");
+MODULE_LICENSE("GPL");
-- 
2.38.1