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From: Ai Chao <aichao@kylinos.cn>
To: hdegoede@redhat.com,
	ilpo.jarvinen@linux.intel.com,
	linux-kernel@vger.kernel.org,
	platform-driver-x86@vger.kernel.org
Cc: Ai Chao <aichao@kylinos.cn>
Subject: [PATCH v4] platform/x86: add lenovo generic wmi driver
Date: Tue,  5 Mar 2024 20:13:15 +0800
Message-Id: <20240305121315.1744363-1-aichao@kylinos.cn>
Precedence: bulk
MIME-Version: 1.0
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Add lenovo generic wmi driver to support camera button.
The Camera button is a GPIO device. This driver receives ACPI notifyi
 when the button pressed.

Signed-off-by: Ai Chao <aichao@kylinos.cn>
---
v4: Remove lenovo_wmi_input_setup, move camera_mode into struct lenovo_wmi_priv.
v3: Remove lenovo_wmi_remove function.
v2: Adjust GPL v2 to GPL, adjust sprintf to sysfs_emit.

 drivers/platform/x86/Kconfig             |  12 +++
 drivers/platform/x86/Makefile            |   1 +
 drivers/platform/x86/lenovo-wmi-camera.c | 118 +++++++++++++++++++++++
 3 files changed, 131 insertions(+)
 create mode 100644 drivers/platform/x86/lenovo-wmi-camera.c

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index bdd302274b9a..079f5aa5910c 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -1001,6 +1001,18 @@ config INSPUR_PLATFORM_PROFILE
 	To compile this driver as a module, choose M here: the module
 	will be called inspur-platform-profile.
 
+config LENOVO_WMI_CAMERA
+	tristate "Lenovo WMI Camera Button driver"
+	depends on ACPI_WMI
+	depends on INPUT
+	help
+	  This driver provides support for Lenovo camera button. The Camera
+	  button is a GPIO device. This driver receives ACPI notify when the
+	  button pressed.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called lenovo-wmi-camera.
+
 source "drivers/platform/x86/x86-android-tablets/Kconfig"
 
 config FW_ATTR_CLASS
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 1de432e8861e..217e94d7c877 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -66,6 +66,7 @@ obj-$(CONFIG_SENSORS_HDAPS)	+= hdaps.o
 obj-$(CONFIG_THINKPAD_ACPI)	+= thinkpad_acpi.o
 obj-$(CONFIG_THINKPAD_LMI)	+= think-lmi.o
 obj-$(CONFIG_YOGABOOK)		+= lenovo-yogabook.o
+obj-$(CONFIG_LENOVO_WMI_CAMERA)	+= lenovo-wmi-camera.o
 
 # Intel
 obj-y				+= intel/
diff --git a/drivers/platform/x86/lenovo-wmi-camera.c b/drivers/platform/x86/lenovo-wmi-camera.c
new file mode 100644
index 000000000000..77084266829c
--- /dev/null
+++ b/drivers/platform/x86/lenovo-wmi-camera.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Lenovo WMI Camera Button Driver
+ *
+ * Author: Ai Chao <aichao@kylinos.cn>
+ * Copyright (C) 2024 KylinSoft Corporation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/wmi.h>
+
+#define WMI_LENOVO_CAMERABUTTON_EVENT_GUID "50C76F1F-D8E4-D895-0A3D-62F4EA400013"
+
+struct lenovo_wmi_priv {
+	struct input_dev *idev;
+	struct device *dev;
+	u8 camera_mode;
+};
+
+enum {
+	CAMERA_BUTTON_PRESSED = 1,
+};
+
+static ssize_t camerabutton_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct lenovo_wmi_priv *priv = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%u\n", priv->camera_mode);
+}
+DEVICE_ATTR_RO(camerabutton);
+
+static struct attribute *lenovo_wmi_attrs[] = {
+	&dev_attr_camerabutton.attr,
+	NULL,
+};
+
+static const struct attribute_group lenovo_wmi_group = {
+	.attrs = lenovo_wmi_attrs,
+};
+
+const struct attribute_group *lenovo_wmi_groups[] = {
+	&lenovo_wmi_group,
+	NULL,
+};
+
+static void lenovo_wmi_notify(struct wmi_device *wdev, union acpi_object *obj)
+{
+	struct lenovo_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
+
+	if (obj->type == ACPI_TYPE_BUFFER &&
+	    obj->buffer.pointer[0] <= CAMERA_BUTTON_PRESSED) {
+		/* Camera mode:
+		 *      0 camera close
+		 *      1 camera open
+		 */
+		priv->camera_mode = obj->buffer.pointer[0];
+
+		input_report_key(priv->idev, KEY_CAMERA, 1);
+		input_sync(priv->idev);
+		input_report_key(priv->idev, KEY_CAMERA, 0);
+		input_sync(priv->idev);
+	} else {
+		dev_dbg(&wdev->dev, "Bad response type %d\n", obj->type);
+	}
+}
+
+static int lenovo_wmi_probe(struct wmi_device *wdev, const void *context)
+{
+	struct lenovo_wmi_priv *priv;
+
+	priv = devm_kzalloc(&wdev->dev, sizeof(*priv),
+			    GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	dev_set_drvdata(&wdev->dev, priv);
+
+	priv->idev = devm_input_allocate_device(&wdev->dev);
+	if (!priv->idev)
+		return -ENOMEM;
+
+	priv->idev->name = "Lenovo WMI Camera Button";
+	priv->idev->phys = "wmi/input0";
+	priv->idev->id.bustype = BUS_HOST;
+	priv->idev->dev.parent = &wdev->dev;
+	set_bit(EV_KEY, priv->idev->evbit);
+	set_bit(KEY_CAMERA, priv->idev->keybit);
+
+	return input_register_device(priv->idev);
+}
+
+static const struct wmi_device_id lenovo_wmi_id_table[] = {
+	{ .guid_string = WMI_LENOVO_CAMERABUTTON_EVENT_GUID },
+	{  }
+};
+
+static struct wmi_driver lenovo_wmi_driver = {
+	.driver = {
+		.name = "lenovo-wmi-camera",
+		.dev_groups = lenovo_wmi_groups,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+	.id_table = lenovo_wmi_id_table,
+	.no_singleton = false,
+	.probe = lenovo_wmi_probe,
+	.notify = lenovo_wmi_notify,
+};
+
+module_wmi_driver(lenovo_wmi_driver);
+
+MODULE_DEVICE_TABLE(wmi, lenovo_wmi_id_table);
+MODULE_AUTHOR("Ai Chao <aichao@kylinos.cn>");
+MODULE_DESCRIPTION("Lenovo Generic WMI Driver");
+MODULE_LICENSE("GPL");
-- 
2.25.1