Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 734 insertions, 0 deletions

diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
new file mode 100644
index 0000000000..1e76a64cce
--- /dev/null
+++ b/drivers/acpi/button.c
@@ -0,0 +1,734 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  button.c - ACPI Button Driver
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ */
+
+#define pr_fmt(fmt) "ACPI: button: " fmt
+
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+#include <acpi/button.h>
+
+#define ACPI_BUTTON_CLASS		"button"
+#define ACPI_BUTTON_FILE_STATE		"state"
+#define ACPI_BUTTON_TYPE_UNKNOWN	0x00
+#define ACPI_BUTTON_NOTIFY_STATUS	0x80
+
+#define ACPI_BUTTON_SUBCLASS_POWER	"power"
+#define ACPI_BUTTON_DEVICE_NAME_POWER	"Power Button"
+#define ACPI_BUTTON_TYPE_POWER		0x01
+
+#define ACPI_BUTTON_SUBCLASS_SLEEP	"sleep"
+#define ACPI_BUTTON_DEVICE_NAME_SLEEP	"Sleep Button"
+#define ACPI_BUTTON_TYPE_SLEEP		0x03
+
+#define ACPI_BUTTON_SUBCLASS_LID	"lid"
+#define ACPI_BUTTON_DEVICE_NAME_LID	"Lid Switch"
+#define ACPI_BUTTON_TYPE_LID		0x05
+
+enum {
+	ACPI_BUTTON_LID_INIT_IGNORE,
+	ACPI_BUTTON_LID_INIT_OPEN,
+	ACPI_BUTTON_LID_INIT_METHOD,
+	ACPI_BUTTON_LID_INIT_DISABLED,
+};
+
+static const char * const lid_init_state_str[] = {
+	[ACPI_BUTTON_LID_INIT_IGNORE]		= "ignore",
+	[ACPI_BUTTON_LID_INIT_OPEN]		= "open",
+	[ACPI_BUTTON_LID_INIT_METHOD]		= "method",
+	[ACPI_BUTTON_LID_INIT_DISABLED]		= "disabled",
+};
+
+MODULE_AUTHOR("Paul Diefenbaugh");
+MODULE_DESCRIPTION("ACPI Button Driver");
+MODULE_LICENSE("GPL");
+
+static const struct acpi_device_id button_device_ids[] = {
+	{ACPI_BUTTON_HID_LID,    0},
+	{ACPI_BUTTON_HID_SLEEP,  0},
+	{ACPI_BUTTON_HID_SLEEPF, 0},
+	{ACPI_BUTTON_HID_POWER,  0},
+	{ACPI_BUTTON_HID_POWERF, 0},
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, button_device_ids);
+
+/* Please keep this list sorted alphabetically by vendor and model */
+static const struct dmi_system_id dmi_lid_quirks[] = {
+	{
+		/* GP-electronic T701, _LID method points to a floating GPIO */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "T701"),
+			DMI_MATCH(DMI_BIOS_VERSION, "BYT70A.YNCHENG.WIN.007"),
+		},
+		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
+	},
+	{
+		/* Nextbook Ares 8A tablet, _LID device always reports lid closed */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "CherryTrail"),
+			DMI_MATCH(DMI_BIOS_VERSION, "M882"),
+		},
+		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
+	},
+	{
+		/*
+		 * Lenovo Yoga 9 14ITL5, initial notification of the LID device
+		 * never happens.
+		 */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "82BG"),
+		},
+		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
+	},
+	{
+		/*
+		 * Medion Akoya E2215T, notification of the LID device only
+		 * happens on close, not on open and _LID always returns closed.
+		 */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "E2215T"),
+		},
+		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
+	},
+	{
+		/*
+		 * Medion Akoya E2228T, notification of the LID device only
+		 * happens on close, not on open and _LID always returns closed.
+		 */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "E2228T"),
+		},
+		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
+	},
+	{
+		/*
+		 * Razer Blade Stealth 13 late 2019, notification of the LID device
+		 * only happens on close, not on open and _LID always returns closed.
+		 */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Razer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Razer Blade Stealth 13 Late 2019"),
+		},
+		.driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
+	},
+	{}
+};
+
+static int acpi_button_add(struct acpi_device *device);
+static void acpi_button_remove(struct acpi_device *device);
+
+#ifdef CONFIG_PM_SLEEP
+static int acpi_button_suspend(struct device *dev);
+static int acpi_button_resume(struct device *dev);
+#else
+#define acpi_button_suspend NULL
+#define acpi_button_resume NULL
+#endif
+static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
+
+static struct acpi_driver acpi_button_driver = {
+	.name = "button",
+	.class = ACPI_BUTTON_CLASS,
+	.ids = button_device_ids,
+	.ops = {
+		.add = acpi_button_add,
+		.remove = acpi_button_remove,
+	},
+	.drv.pm = &acpi_button_pm,
+};
+
+struct acpi_button {
+	unsigned int type;
+	struct input_dev *input;
+	char phys[32];			/* for input device */
+	unsigned long pushed;
+	int last_state;
+	ktime_t last_time;
+	bool suspended;
+	bool lid_state_initialized;
+};
+
+static struct acpi_device *lid_device;
+static long lid_init_state = -1;
+
+static unsigned long lid_report_interval __read_mostly = 500;
+module_param(lid_report_interval, ulong, 0644);
+MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
+
+/* FS Interface (/proc) */
+static struct proc_dir_entry *acpi_button_dir;
+static struct proc_dir_entry *acpi_lid_dir;
+
+static int acpi_lid_evaluate_state(struct acpi_device *device)
+{
+	unsigned long long lid_state;
+	acpi_status status;
+
+	status = acpi_evaluate_integer(device->handle, "_LID", NULL, &lid_state);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	return lid_state ? 1 : 0;
+}
+
+static int acpi_lid_notify_state(struct acpi_device *device, int state)
+{
+	struct acpi_button *button = acpi_driver_data(device);
+	ktime_t next_report;
+	bool do_update;
+
+	/*
+	 * In lid_init_state=ignore mode, if user opens/closes lid
+	 * frequently with "open" missing, and "last_time" is also updated
+	 * frequently, "close" cannot be delivered to the userspace.
+	 * So "last_time" is only updated after a timeout or an actual
+	 * switch.
+	 */
+	if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||
+	    button->last_state != !!state)
+		do_update = true;
+	else
+		do_update = false;
+
+	next_report = ktime_add(button->last_time,
+				ms_to_ktime(lid_report_interval));
+	if (button->last_state == !!state &&
+	    ktime_after(ktime_get(), next_report)) {
+		/* Complain the buggy firmware */
+		pr_warn_once("The lid device is not compliant to SW_LID.\n");
+
+		/*
+		 * Send the unreliable complement switch event:
+		 *
+		 * On most platforms, the lid device is reliable. However
+		 * there are exceptions:
+		 * 1. Platforms returning initial lid state as "close" by
+		 *    default after booting/resuming:
+		 *     https://bugzilla.kernel.org/show_bug.cgi?id=89211
+		 *     https://bugzilla.kernel.org/show_bug.cgi?id=106151
+		 * 2. Platforms never reporting "open" events:
+		 *     https://bugzilla.kernel.org/show_bug.cgi?id=106941
+		 * On these buggy platforms, the usage model of the ACPI
+		 * lid device actually is:
+		 * 1. The initial returning value of _LID may not be
+		 *    reliable.
+		 * 2. The open event may not be reliable.
+		 * 3. The close event is reliable.
+		 *
+		 * But SW_LID is typed as input switch event, the input
+		 * layer checks if the event is redundant. Hence if the
+		 * state is not switched, the userspace cannot see this
+		 * platform triggered reliable event. By inserting a
+		 * complement switch event, it then is guaranteed that the
+		 * platform triggered reliable one can always be seen by
+		 * the userspace.
+		 */
+		if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) {
+			do_update = true;
+			/*
+			 * Do generate complement switch event for "close"
+			 * as "close" is reliable and wrong "open" won't
+			 * trigger unexpected behaviors.
+			 * Do not generate complement switch event for
+			 * "open" as "open" is not reliable and wrong
+			 * "close" will trigger unexpected behaviors.
+			 */
+			if (!state) {
+				input_report_switch(button->input,
+						    SW_LID, state);
+				input_sync(button->input);
+			}
+		}
+	}
+	/* Send the platform triggered reliable event */
+	if (do_update) {
+		acpi_handle_debug(device->handle, "ACPI LID %s\n",
+				  state ? "open" : "closed");
+		input_report_switch(button->input, SW_LID, !state);
+		input_sync(button->input);
+		button->last_state = !!state;
+		button->last_time = ktime_get();
+	}
+
+	return 0;
+}
+
+static int __maybe_unused acpi_button_state_seq_show(struct seq_file *seq,
+						     void *offset)
+{
+	struct acpi_device *device = seq->private;
+	int state;
+
+	state = acpi_lid_evaluate_state(device);
+	seq_printf(seq, "state:      %s\n",
+		   state < 0 ? "unsupported" : (state ? "open" : "closed"));
+	return 0;
+}
+
+static int acpi_button_add_fs(struct acpi_device *device)
+{
+	struct acpi_button *button = acpi_driver_data(device);
+	struct proc_dir_entry *entry = NULL;
+	int ret = 0;
+
+	/* procfs I/F for ACPI lid device only */
+	if (button->type != ACPI_BUTTON_TYPE_LID)
+		return 0;
+
+	if (acpi_button_dir || acpi_lid_dir) {
+		pr_info("More than one Lid device found!\n");
+		return -EEXIST;
+	}
+
+	/* create /proc/acpi/button */
+	acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
+	if (!acpi_button_dir)
+		return -ENODEV;
+
+	/* create /proc/acpi/button/lid */
+	acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
+	if (!acpi_lid_dir) {
+		ret = -ENODEV;
+		goto remove_button_dir;
+	}
+
+	/* create /proc/acpi/button/lid/LID/ */
+	acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
+	if (!acpi_device_dir(device)) {
+		ret = -ENODEV;
+		goto remove_lid_dir;
+	}
+
+	/* create /proc/acpi/button/lid/LID/state */
+	entry = proc_create_single_data(ACPI_BUTTON_FILE_STATE, S_IRUGO,
+			acpi_device_dir(device), acpi_button_state_seq_show,
+			device);
+	if (!entry) {
+		ret = -ENODEV;
+		goto remove_dev_dir;
+	}
+
+done:
+	return ret;
+
+remove_dev_dir:
+	remove_proc_entry(acpi_device_bid(device),
+			  acpi_lid_dir);
+	acpi_device_dir(device) = NULL;
+remove_lid_dir:
+	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
+	acpi_lid_dir = NULL;
+remove_button_dir:
+	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
+	acpi_button_dir = NULL;
+	goto done;
+}
+
+static int acpi_button_remove_fs(struct acpi_device *device)
+{
+	struct acpi_button *button = acpi_driver_data(device);
+
+	if (button->type != ACPI_BUTTON_TYPE_LID)
+		return 0;
+
+	remove_proc_entry(ACPI_BUTTON_FILE_STATE,
+			  acpi_device_dir(device));
+	remove_proc_entry(acpi_device_bid(device),
+			  acpi_lid_dir);
+	acpi_device_dir(device) = NULL;
+	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
+	acpi_lid_dir = NULL;
+	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
+	acpi_button_dir = NULL;
+
+	return 0;
+}
+
+/* Driver Interface */
+int acpi_lid_open(void)
+{
+	if (!lid_device)
+		return -ENODEV;
+
+	return acpi_lid_evaluate_state(lid_device);
+}
+EXPORT_SYMBOL(acpi_lid_open);
+
+static int acpi_lid_update_state(struct acpi_device *device,
+				 bool signal_wakeup)
+{
+	int state;
+
+	state = acpi_lid_evaluate_state(device);
+	if (state < 0)
+		return state;
+
+	if (state && signal_wakeup)
+		acpi_pm_wakeup_event(&device->dev);
+
+	return acpi_lid_notify_state(device, state);
+}
+
+static void acpi_lid_initialize_state(struct acpi_device *device)
+{
+	struct acpi_button *button = acpi_driver_data(device);
+
+	switch (lid_init_state) {
+	case ACPI_BUTTON_LID_INIT_OPEN:
+		(void)acpi_lid_notify_state(device, 1);
+		break;
+	case ACPI_BUTTON_LID_INIT_METHOD:
+		(void)acpi_lid_update_state(device, false);
+		break;
+	case ACPI_BUTTON_LID_INIT_IGNORE:
+	default:
+		break;
+	}
+
+	button->lid_state_initialized = true;
+}
+
+static void acpi_lid_notify(acpi_handle handle, u32 event, void *data)
+{
+	struct acpi_device *device = data;
+	struct acpi_button *button;
+
+	if (event != ACPI_BUTTON_NOTIFY_STATUS) {
+		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
+				  event);
+		return;
+	}
+
+	button = acpi_driver_data(device);
+	if (!button->lid_state_initialized)
+		return;
+
+	acpi_lid_update_state(device, true);
+}
+
+static void acpi_button_notify(acpi_handle handle, u32 event, void *data)
+{
+	struct acpi_device *device = data;
+	struct acpi_button *button;
+	struct input_dev *input;
+	int keycode;
+
+	if (event != ACPI_BUTTON_NOTIFY_STATUS) {
+		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
+				  event);
+		return;
+	}
+
+	acpi_pm_wakeup_event(&device->dev);
+
+	button = acpi_driver_data(device);
+	if (button->suspended)
+		return;
+
+	input = button->input;
+	keycode = test_bit(KEY_SLEEP, input->keybit) ? KEY_SLEEP : KEY_POWER;
+
+	input_report_key(input, keycode, 1);
+	input_sync(input);
+	input_report_key(input, keycode, 0);
+	input_sync(input);
+
+	acpi_bus_generate_netlink_event(device->pnp.device_class,
+					dev_name(&device->dev),
+					event, ++button->pushed);
+}
+
+static void acpi_button_notify_run(void *data)
+{
+	acpi_button_notify(NULL, ACPI_BUTTON_NOTIFY_STATUS, data);
+}
+
+static u32 acpi_button_event(void *data)
+{
+	acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_button_notify_run, data);
+	return ACPI_INTERRUPT_HANDLED;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int acpi_button_suspend(struct device *dev)
+{
+	struct acpi_device *device = to_acpi_device(dev);
+	struct acpi_button *button = acpi_driver_data(device);
+
+	button->suspended = true;
+	return 0;
+}
+
+static int acpi_button_resume(struct device *dev)
+{
+	struct acpi_device *device = to_acpi_device(dev);
+	struct acpi_button *button = acpi_driver_data(device);
+
+	button->suspended = false;
+	if (button->type == ACPI_BUTTON_TYPE_LID) {
+		button->last_state = !!acpi_lid_evaluate_state(device);
+		button->last_time = ktime_get();
+		acpi_lid_initialize_state(device);
+	}
+	return 0;
+}
+#endif
+
+static int acpi_lid_input_open(struct input_dev *input)
+{
+	struct acpi_device *device = input_get_drvdata(input);
+	struct acpi_button *button = acpi_driver_data(device);
+
+	button->last_state = !!acpi_lid_evaluate_state(device);
+	button->last_time = ktime_get();
+	acpi_lid_initialize_state(device);
+
+	return 0;
+}
+
+static int acpi_button_add(struct acpi_device *device)
+{
+	acpi_notify_handler handler;
+	struct acpi_button *button;
+	struct input_dev *input;
+	const char *hid = acpi_device_hid(device);
+	acpi_status status;
+	char *name, *class;
+	int error = 0;
+
+	if (!strcmp(hid, ACPI_BUTTON_HID_LID) &&
+	     lid_init_state == ACPI_BUTTON_LID_INIT_DISABLED)
+		return -ENODEV;
+
+	button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
+	if (!button)
+		return -ENOMEM;
+
+	device->driver_data = button;
+
+	button->input = input = input_allocate_device();
+	if (!input) {
+		error = -ENOMEM;
+		goto err_free_button;
+	}
+
+	name = acpi_device_name(device);
+	class = acpi_device_class(device);
+
+	if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
+	    !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
+		button->type = ACPI_BUTTON_TYPE_POWER;
+		handler = acpi_button_notify;
+		strcpy(name, ACPI_BUTTON_DEVICE_NAME_POWER);
+		sprintf(class, "%s/%s",
+			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
+	} else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
+		   !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
+		button->type = ACPI_BUTTON_TYPE_SLEEP;
+		handler = acpi_button_notify;
+		strcpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP);
+		sprintf(class, "%s/%s",
+			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
+	} else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
+		button->type = ACPI_BUTTON_TYPE_LID;
+		handler = acpi_lid_notify;
+		strcpy(name, ACPI_BUTTON_DEVICE_NAME_LID);
+		sprintf(class, "%s/%s",
+			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
+		input->open = acpi_lid_input_open;
+	} else {
+		pr_info("Unsupported hid [%s]\n", hid);
+		error = -ENODEV;
+	}
+
+	if (!error)
+		error = acpi_button_add_fs(device);
+
+	if (error) {
+		input_free_device(input);
+		goto err_free_button;
+	}
+
+	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
+
+	input->name = name;
+	input->phys = button->phys;
+	input->id.bustype = BUS_HOST;
+	input->id.product = button->type;
+	input->dev.parent = &device->dev;
+
+	switch (button->type) {
+	case ACPI_BUTTON_TYPE_POWER:
+		input_set_capability(input, EV_KEY, KEY_POWER);
+		break;
+
+	case ACPI_BUTTON_TYPE_SLEEP:
+		input_set_capability(input, EV_KEY, KEY_SLEEP);
+		break;
+
+	case ACPI_BUTTON_TYPE_LID:
+		input_set_capability(input, EV_SW, SW_LID);
+		break;
+	}
+
+	input_set_drvdata(input, device);
+	error = input_register_device(input);
+	if (error)
+		goto err_remove_fs;
+
+	switch (device->device_type) {
+	case ACPI_BUS_TYPE_POWER_BUTTON:
+		status = acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
+							  acpi_button_event,
+							  device);
+		break;
+	case ACPI_BUS_TYPE_SLEEP_BUTTON:
+		status = acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
+							  acpi_button_event,
+							  device);
+		break;
+	default:
+		status = acpi_install_notify_handler(device->handle,
+						     ACPI_DEVICE_NOTIFY, handler,
+						     device);
+		break;
+	}
+	if (ACPI_FAILURE(status)) {
+		error = -ENODEV;
+		goto err_input_unregister;
+	}
+
+	if (button->type == ACPI_BUTTON_TYPE_LID) {
+		/*
+		 * This assumes there's only one lid device, or if there are
+		 * more we only care about the last one...
+		 */
+		lid_device = device;
+	}
+
+	device_init_wakeup(&device->dev, true);
+	pr_info("%s [%s]\n", name, acpi_device_bid(device));
+	return 0;
+
+err_input_unregister:
+	input_unregister_device(input);
+err_remove_fs:
+	acpi_button_remove_fs(device);
+err_free_button:
+	kfree(button);
+	return error;
+}
+
+static void acpi_button_remove(struct acpi_device *device)
+{
+	struct acpi_button *button = acpi_driver_data(device);
+
+	switch (device->device_type) {
+	case ACPI_BUS_TYPE_POWER_BUTTON:
+		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
+						acpi_button_event);
+		break;
+	case ACPI_BUS_TYPE_SLEEP_BUTTON:
+		acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
+						acpi_button_event);
+		break;
+	default:
+		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
+					   button->type == ACPI_BUTTON_TYPE_LID ?
+						acpi_lid_notify :
+						acpi_button_notify);
+		break;
+	}
+	acpi_os_wait_events_complete();
+
+	acpi_button_remove_fs(device);
+	input_unregister_device(button->input);
+	kfree(button);
+}
+
+static int param_set_lid_init_state(const char *val,
+				    const struct kernel_param *kp)
+{
+	int i;
+
+	i = sysfs_match_string(lid_init_state_str, val);
+	if (i < 0)
+		return i;
+
+	lid_init_state = i;
+	pr_info("Initial lid state set to '%s'\n", lid_init_state_str[i]);
+	return 0;
+}
+
+static int param_get_lid_init_state(char *buf, const struct kernel_param *kp)
+{
+	int i, c = 0;
+
+	for (i = 0; i < ARRAY_SIZE(lid_init_state_str); i++)
+		if (i == lid_init_state)
+			c += sprintf(buf + c, "[%s] ", lid_init_state_str[i]);
+		else
+			c += sprintf(buf + c, "%s ", lid_init_state_str[i]);
+
+	buf[c - 1] = '\n'; /* Replace the final space with a newline */
+
+	return c;
+}
+
+module_param_call(lid_init_state,
+		  param_set_lid_init_state, param_get_lid_init_state,
+		  NULL, 0644);
+MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
+
+static int acpi_button_register_driver(struct acpi_driver *driver)
+{
+	const struct dmi_system_id *dmi_id;
+
+	if (lid_init_state == -1) {
+		dmi_id = dmi_first_match(dmi_lid_quirks);
+		if (dmi_id)
+			lid_init_state = (long)dmi_id->driver_data;
+		else
+			lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
+	}
+
+	/*
+	 * Modules such as nouveau.ko and i915.ko have a link time dependency
+	 * on acpi_lid_open(), and would therefore not be loadable on ACPI
+	 * capable kernels booted in non-ACPI mode if the return value of
+	 * acpi_bus_register_driver() is returned from here with ACPI disabled
+	 * when this driver is built as a module.
+	 */
+	if (acpi_disabled)
+		return 0;
+
+	return acpi_bus_register_driver(driver);
+}
+
+static void acpi_button_unregister_driver(struct acpi_driver *driver)
+{
+	if (!acpi_disabled)
+		acpi_bus_unregister_driver(driver);
+}
+
+module_driver(acpi_button_driver, acpi_button_register_driver,
+	       acpi_button_unregister_driver);