1 files changed, 422 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel/vbtn.c b/drivers/platform/x86/intel/vbtn.c
new file mode 100644
index 000000000..8e2b07ed2
--- /dev/null
+++ b/drivers/platform/x86/intel/vbtn.c
@@ -0,0 +1,422 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  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>
+ */
+
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+#include <linux/input.h>
+#include <linux/input/sparse-keymap.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/suspend.h>
+#include "../dual_accel_detect.h"
+
+/* Returned when NOT in tablet mode on some HP Stream x360 11 models */
+#define VGBS_TABLET_MODE_FLAG_ALT	0x10
+/* When NOT in tablet mode, VGBS returns with the flag 0x40 */
+#define VGBS_TABLET_MODE_FLAG		0x40
+#define VGBS_DOCK_MODE_FLAG		0x80
+
+#define VGBS_TABLET_MODE_FLAGS (VGBS_TABLET_MODE_FLAG | VGBS_TABLET_MODE_FLAG_ALT)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("AceLan Kao");
+
+static const struct acpi_device_id intel_vbtn_ids[] = {
+	{"INT33D6", 0},
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
+
+/* In theory, these are HID usages. */
+static const struct key_entry intel_vbtn_keymap[] = {
+	{ KE_KEY, 0xC0, { KEY_POWER } },	/* power key press */
+	{ KE_IGNORE, 0xC1, { KEY_POWER } },	/* power key release */
+	{ KE_KEY, 0xC2, { KEY_LEFTMETA } },		/* 'Windows' key press */
+	{ KE_KEY, 0xC3, { KEY_LEFTMETA } },		/* 'Windows' key release */
+	{ KE_KEY, 0xC4, { KEY_VOLUMEUP } },		/* volume-up key press */
+	{ KE_IGNORE, 0xC5, { KEY_VOLUMEUP } },		/* volume-up key release */
+	{ KE_KEY, 0xC6, { KEY_VOLUMEDOWN } },		/* volume-down key press */
+	{ KE_IGNORE, 0xC7, { KEY_VOLUMEDOWN } },	/* volume-down key release */
+	{ KE_KEY,    0xC8, { KEY_ROTATE_LOCK_TOGGLE } },	/* rotate-lock key press */
+	{ KE_KEY,    0xC9, { KEY_ROTATE_LOCK_TOGGLE } },	/* rotate-lock key release */
+	{ KE_END }
+};
+
+static const struct key_entry intel_vbtn_switchmap[] = {
+	/*
+	 * SW_DOCK should only be reported for docking stations, but DSDTs using the
+	 * intel-vbtn code, always seem to use this for 2-in-1s / convertibles and set
+	 * SW_DOCK=1 when in laptop-mode (in tandem with setting SW_TABLET_MODE=0).
+	 * This causes userspace to think the laptop is docked to a port-replicator
+	 * and to disable suspend-on-lid-close, which is undesirable.
+	 * Map the dock events to KEY_IGNORE to avoid this broken SW_DOCK reporting.
+	 */
+	{ KE_IGNORE, 0xCA, { .sw = { SW_DOCK, 1 } } },		/* Docked */
+	{ KE_IGNORE, 0xCB, { .sw = { SW_DOCK, 0 } } },		/* Undocked */
+	{ KE_SW,     0xCC, { .sw = { SW_TABLET_MODE, 1 } } },	/* Tablet */
+	{ KE_SW,     0xCD, { .sw = { SW_TABLET_MODE, 0 } } },	/* Laptop */
+	{ KE_END }
+};
+
+struct intel_vbtn_priv {
+	struct input_dev *buttons_dev;
+	struct input_dev *switches_dev;
+	bool dual_accel;
+	bool has_buttons;
+	bool has_switches;
+	bool wakeup_mode;
+};
+
+static void detect_tablet_mode(struct device *dev)
+{
+	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
+	acpi_handle handle = ACPI_HANDLE(dev);
+	unsigned long long vgbs;
+	acpi_status status;
+	int m;
+
+	status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
+	if (ACPI_FAILURE(status))
+		return;
+
+	m = !(vgbs & VGBS_TABLET_MODE_FLAGS);
+	input_report_switch(priv->switches_dev, SW_TABLET_MODE, m);
+	m = (vgbs & VGBS_DOCK_MODE_FLAG) ? 1 : 0;
+	input_report_switch(priv->switches_dev, SW_DOCK, m);
+
+	input_sync(priv->switches_dev);
+}
+
+/*
+ * Note this unconditionally creates the 2 input_dev-s and sets up
+ * the sparse-keymaps. Only the registration is conditional on
+ * have_buttons / have_switches. This is done so that the notify
+ * handler can always call sparse_keymap_entry_from_scancode()
+ * on the input_dev-s do determine the event type.
+ */
+static int intel_vbtn_input_setup(struct platform_device *device)
+{
+	struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
+	int ret;
+
+	priv->buttons_dev = devm_input_allocate_device(&device->dev);
+	if (!priv->buttons_dev)
+		return -ENOMEM;
+
+	ret = sparse_keymap_setup(priv->buttons_dev, intel_vbtn_keymap, NULL);
+	if (ret)
+		return ret;
+
+	priv->buttons_dev->dev.parent = &device->dev;
+	priv->buttons_dev->name = "Intel Virtual Buttons";
+	priv->buttons_dev->id.bustype = BUS_HOST;
+
+	if (priv->has_buttons) {
+		ret = input_register_device(priv->buttons_dev);
+		if (ret)
+			return ret;
+	}
+
+	priv->switches_dev = devm_input_allocate_device(&device->dev);
+	if (!priv->switches_dev)
+		return -ENOMEM;
+
+	ret = sparse_keymap_setup(priv->switches_dev, intel_vbtn_switchmap, NULL);
+	if (ret)
+		return ret;
+
+	priv->switches_dev->dev.parent = &device->dev;
+	priv->switches_dev->name = "Intel Virtual Switches";
+	priv->switches_dev->id.bustype = BUS_HOST;
+
+	if (priv->has_switches) {
+		detect_tablet_mode(&device->dev);
+
+		ret = input_register_device(priv->switches_dev);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+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);
+	unsigned int val = !(event & 1); /* Even=press, Odd=release */
+	const struct key_entry *ke, *ke_rel;
+	struct input_dev *input_dev;
+	bool autorelease;
+	int ret;
+
+	if ((ke = sparse_keymap_entry_from_scancode(priv->buttons_dev, event))) {
+		if (!priv->has_buttons) {
+			dev_warn(&device->dev, "Warning: received a button event on a device without buttons, please report this.\n");
+			return;
+		}
+		input_dev = priv->buttons_dev;
+	} else if ((ke = sparse_keymap_entry_from_scancode(priv->switches_dev, event))) {
+		if (!priv->has_switches) {
+			/* See dual_accel_detect.h for more info */
+			if (priv->dual_accel)
+				return;
+
+			dev_info(&device->dev, "Registering Intel Virtual Switches input-dev after receiving a switch event\n");
+			ret = input_register_device(priv->switches_dev);
+			if (ret)
+				return;
+
+			priv->has_switches = true;
+		}
+		input_dev = priv->switches_dev;
+	} else {
+		dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
+		return;
+	}
+
+	if (priv->wakeup_mode) {
+		pm_wakeup_hard_event(&device->dev);
+
+		/*
+		 * Skip reporting an evdev event for button wake events,
+		 * mirroring how the drivers/acpi/button.c code skips this too.
+		 */
+		if (ke->type == KE_KEY)
+			return;
+	}
+
+	/*
+	 * Even press events are autorelease if there is no corresponding odd
+	 * release event, or if the odd event is KE_IGNORE.
+	 */
+	ke_rel = sparse_keymap_entry_from_scancode(input_dev, event | 1);
+	autorelease = val && (!ke_rel || ke_rel->type == KE_IGNORE);
+
+	sparse_keymap_report_event(input_dev, event, val, autorelease);
+
+	/* Some devices need this to report further events */
+	acpi_evaluate_object(handle, "VBDL", NULL, NULL);
+}
+
+/*
+ * There are several laptops (non 2-in-1) models out there which support VGBS,
+ * but simply always return 0, which we translate to SW_TABLET_MODE=1. This in
+ * turn causes userspace (libinput) to suppress events from the builtin
+ * keyboard and touchpad, making the laptop essentially unusable.
+ *
+ * Since the problem of wrongly reporting SW_TABLET_MODE=1 in combination
+ * with libinput, leads to a non-usable system. Where as OTOH many people will
+ * not even notice when SW_TABLET_MODE is not being reported, a DMI based allow
+ * list is used here. This list mainly matches on the chassis-type of 2-in-1s.
+ *
+ * There are also some 2-in-1s which use the intel-vbtn ACPI interface to report
+ * SW_TABLET_MODE with a chassis-type of 8 ("Portable") or 10 ("Notebook"),
+ * these are matched on a per model basis, since many normal laptops with a
+ * possible broken VGBS ACPI-method also use these chassis-types.
+ */
+static const struct dmi_system_id dmi_switches_allow_list[] = {
+	{
+		.matches = {
+			DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "31" /* Convertible */),
+		},
+	},
+	{
+		.matches = {
+			DMI_EXACT_MATCH(DMI_CHASSIS_TYPE, "32" /* Detachable */),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Venue 11 Pro 7130"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion 13 x360 PC"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Switch SA5-271"),
+		},
+	},
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7352"),
+		},
+	},
+	{} /* Array terminator */
+};
+
+static bool intel_vbtn_has_switches(acpi_handle handle, bool dual_accel)
+{
+	unsigned long long vgbs;
+	acpi_status status;
+
+	/* See dual_accel_detect.h for more info */
+	if (dual_accel)
+		return false;
+
+	if (!dmi_check_system(dmi_switches_allow_list))
+		return false;
+
+	status = acpi_evaluate_integer(handle, "VGBS", NULL, &vgbs);
+	return ACPI_SUCCESS(status);
+}
+
+static int intel_vbtn_probe(struct platform_device *device)
+{
+	acpi_handle handle = ACPI_HANDLE(&device->dev);
+	bool dual_accel, has_buttons, has_switches;
+	struct intel_vbtn_priv *priv;
+	acpi_status status;
+	int err;
+
+	dual_accel = dual_accel_detect();
+	has_buttons = acpi_has_method(handle, "VBDL");
+	has_switches = intel_vbtn_has_switches(handle, dual_accel);
+
+	if (!has_buttons && !has_switches) {
+		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);
+
+	priv->dual_accel = dual_accel;
+	priv->has_buttons = has_buttons;
+	priv->has_switches = has_switches;
+
+	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))
+		return -EBUSY;
+
+	if (has_buttons) {
+		status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
+		if (ACPI_FAILURE(status))
+			dev_err(&device->dev, "Error VBDL failed with ACPI status %d\n", status);
+	}
+
+	device_init_wakeup(&device->dev, true);
+	/*
+	 * In order for system wakeup to work, the EC GPE has to be marked as
+	 * a wakeup one, so do that here (this setting will persist, but it has
+	 * no effect until the wakeup mask is set for the EC GPE).
+	 */
+	acpi_ec_mark_gpe_for_wake();
+	return 0;
+}
+
+static int intel_vbtn_remove(struct platform_device *device)
+{
+	acpi_handle handle = ACPI_HANDLE(&device->dev);
+
+	device_init_wakeup(&device->dev, false);
+	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 int intel_vbtn_pm_prepare(struct device *dev)
+{
+	if (device_may_wakeup(dev)) {
+		struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
+
+		priv->wakeup_mode = true;
+	}
+	return 0;
+}
+
+static void intel_vbtn_pm_complete(struct device *dev)
+{
+	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
+
+	priv->wakeup_mode = false;
+}
+
+static int intel_vbtn_pm_resume(struct device *dev)
+{
+	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
+
+	intel_vbtn_pm_complete(dev);
+
+	if (priv->has_switches)
+		detect_tablet_mode(dev);
+
+	return 0;
+}
+
+static const struct dev_pm_ops intel_vbtn_pm_ops = {
+	.prepare = intel_vbtn_pm_prepare,
+	.complete = intel_vbtn_pm_complete,
+	.resume = intel_vbtn_pm_resume,
+	.restore = intel_vbtn_pm_resume,
+	.thaw = intel_vbtn_pm_resume,
+};
+
+static struct platform_driver intel_vbtn_pl_driver = {
+	.driver = {
+		.name = "intel-vbtn",
+		.acpi_match_table = intel_vbtn_ids,
+		.pm = &intel_vbtn_pm_ops,
+	},
+	.probe = intel_vbtn_probe,
+	.remove = intel_vbtn_remove,
+};
+
+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 = acpi_fetch_acpi_dev(handle);
+
+	if (dev && acpi_match_device_ids(dev, ids) == 0)
+		if (!IS_ERR_OR_NULL(acpi_create_platform_device(dev, NULL)))
+			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);