--- /dev/null
+/*
+ * Intel Virtual Button driver for Windows 8.1+
+ *
+ * Copyright (C) 2016 AceLan Kao <acelan.kao@canonical.com>
+ * Copyright (C) 2016 Alex Hung <alex.hung@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/platform_device.h>
+#include <linux/input/sparse-keymap.h>
+#include <linux/acpi.h>
+#include <acpi/acpi_bus.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("AceLan Kao");
+
+static const struct acpi_device_id intel_vbtn_ids[] = {
+ {"INT33D6", 0},
+ {"", 0},
+};
+
+/* In theory, these are HID usages. */
+static const struct key_entry intel_vbtn_keymap[] = {
+ { KE_IGNORE, 0xC0, { KEY_POWER } }, /* power key press */
+ { KE_KEY, 0xC1, { KEY_POWER } }, /* power key release */
+ { KE_END },
+};
+
+struct intel_vbtn_priv {
+ struct input_dev *input_dev;
+};
+
+static int intel_vbtn_input_setup(struct platform_device *device)
+{
+ struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
+ int ret;
+
+ priv->input_dev = input_allocate_device();
+ if (!priv->input_dev)
+ return -ENOMEM;
+
+ ret = sparse_keymap_setup(priv->input_dev, intel_vbtn_keymap, NULL);
+ if (ret)
+ goto err_free_device;
+
+ priv->input_dev->dev.parent = &device->dev;
+ priv->input_dev->name = "Intel Virtual Button driver";
+ priv->input_dev->id.bustype = BUS_HOST;
+
+ ret = input_register_device(priv->input_dev);
+ if (ret)
+ goto err_free_device;
+
+ return 0;
+
+err_free_device:
+ input_free_device(priv->input_dev);
+ return ret;
+}
+
+static void intel_vbtn_input_destroy(struct platform_device *device)
+{
+ struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
+
+ input_unregister_device(priv->input_dev);
+}
+
+static void notify_handler(acpi_handle handle, u32 event, void *context)
+{
+ struct platform_device *device = context;
+ struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
+
+ if (!sparse_keymap_report_event(priv->input_dev, event, 1, true))
+ dev_info(&device->dev, "unknown event index 0x%x\n",
+ event);
+}
+
+static int intel_vbtn_probe(struct platform_device *device)
+{
+ acpi_handle handle = ACPI_HANDLE(&device->dev);
+ struct intel_vbtn_priv *priv;
+ acpi_status status;
+ int err;
+
+ status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
+ if (!ACPI_SUCCESS(status)) {
+ dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
+ return -ENODEV;
+ }
+
+ priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ dev_set_drvdata(&device->dev, priv);
+
+ err = intel_vbtn_input_setup(device);
+ if (err) {
+ pr_err("Failed to setup Intel Virtual Button\n");
+ return err;
+ }
+
+ status = acpi_install_notify_handler(handle,
+ ACPI_DEVICE_NOTIFY,
+ notify_handler,
+ device);
+ if (ACPI_FAILURE(status)) {
+ err = -EBUSY;
+ goto err_remove_input;
+ }
+
+ return 0;
+
+err_remove_input:
+ intel_vbtn_input_destroy(device);
+
+ return err;
+}
+
+static int intel_vbtn_remove(struct platform_device *device)
+{
+ acpi_handle handle = ACPI_HANDLE(&device->dev);
+
+ intel_vbtn_input_destroy(device);
+ acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
+
+ /*
+ * Even if we failed to shut off the event stream, we can still
+ * safely detach from the device.
+ */
+ return 0;
+}
+
+static struct platform_driver intel_vbtn_pl_driver = {
+ .driver = {
+ .name = "intel-vbtn",
+ .acpi_match_table = intel_vbtn_ids,
+ },
+ .probe = intel_vbtn_probe,
+ .remove = intel_vbtn_remove,
+};
+MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
+
+static acpi_status __init
+check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
+{
+ const struct acpi_device_id *ids = context;
+ struct acpi_device *dev;
+
+ if (acpi_bus_get_device(handle, &dev) != 0)
+ return AE_OK;
+
+ if (acpi_match_device_ids(dev, ids) == 0)
+ if (acpi_create_platform_device(dev))
+ dev_info(&dev->dev,
+ "intel-vbtn: created platform device\n");
+
+ return AE_OK;
+}
+
+static int __init intel_vbtn_init(void)
+{
+ acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX, check_acpi_dev, NULL,
+ (void *)intel_vbtn_ids, NULL);
+
+ return platform_driver_register(&intel_vbtn_pl_driver);
+}
+module_init(intel_vbtn_init);
+
+static void __exit intel_vbtn_exit(void)
+{
+ platform_driver_unregister(&intel_vbtn_pl_driver);
+}
+module_exit(intel_vbtn_exit);