Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 740 insertions, 0 deletions

diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c
new file mode 100644
index 000000000..16c7f3d9a
--- /dev/null
+++ b/drivers/platform/x86/dell-wmi.c
@@ -0,0 +1,740 @@
+/*
+ * Dell WMI hotkeys
+ *
+ * Copyright (C) 2008 Red Hat <mjg@redhat.com>
+ * Copyright (C) 2014-2015 Pali Rohár <pali.rohar@gmail.com>
+ *
+ * Portions based on wistron_btns.c:
+ * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
+ * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
+ * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
+ *
+ *  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.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/input.h>
+#include <linux/input/sparse-keymap.h>
+#include <linux/acpi.h>
+#include <linux/string.h>
+#include <linux/dmi.h>
+#include <linux/wmi.h>
+#include <acpi/video.h>
+#include "dell-smbios.h"
+#include "dell-wmi-descriptor.h"
+
+MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
+MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
+MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver");
+MODULE_LICENSE("GPL");
+
+#define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"
+
+static bool wmi_requires_smbios_request;
+
+MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
+
+struct dell_wmi_priv {
+	struct input_dev *input_dev;
+	u32 interface_version;
+};
+
+static int __init dmi_matched(const struct dmi_system_id *dmi)
+{
+	wmi_requires_smbios_request = 1;
+	return 1;
+}
+
+static const struct dmi_system_id dell_wmi_smbios_list[] __initconst = {
+	{
+		.callback = dmi_matched,
+		.ident = "Dell Inspiron M5110",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron M5110"),
+		},
+	},
+	{
+		.callback = dmi_matched,
+		.ident = "Dell Vostro V131",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
+		},
+	},
+	{ }
+};
+
+/*
+ * Keymap for WMI events of type 0x0000
+ *
+ * Certain keys are flagged as KE_IGNORE. All of these are either
+ * notifications (rather than requests for change) or are also sent
+ * via the keyboard controller so should not be sent again.
+ */
+static const struct key_entry dell_wmi_keymap_type_0000[] = {
+	{ KE_IGNORE, 0x003a, { KEY_CAPSLOCK } },
+
+	/* Key code is followed by brightness level */
+	{ KE_KEY,    0xe005, { KEY_BRIGHTNESSDOWN } },
+	{ KE_KEY,    0xe006, { KEY_BRIGHTNESSUP } },
+
+	/* Battery health status button */
+	{ KE_KEY,    0xe007, { KEY_BATTERY } },
+
+	/* Radio devices state change, key code is followed by other values */
+	{ KE_IGNORE, 0xe008, { KEY_RFKILL } },
+
+	{ KE_KEY,    0xe009, { KEY_EJECTCD } },
+
+	/* Key code is followed by: next, active and attached devices */
+	{ KE_KEY,    0xe00b, { KEY_SWITCHVIDEOMODE } },
+
+	/* Key code is followed by keyboard illumination level */
+	{ KE_IGNORE, 0xe00c, { KEY_KBDILLUMTOGGLE } },
+
+	/* BIOS error detected */
+	{ KE_IGNORE, 0xe00d, { KEY_RESERVED } },
+
+	/* Battery was removed or inserted */
+	{ KE_IGNORE, 0xe00e, { KEY_RESERVED } },
+
+	/* Wifi Catcher */
+	{ KE_KEY,    0xe011, { KEY_WLAN } },
+
+	/* Ambient light sensor toggle */
+	{ KE_IGNORE, 0xe013, { KEY_RESERVED } },
+
+	{ KE_IGNORE, 0xe020, { KEY_MUTE } },
+
+	/* Unknown, defined in ACPI DSDT */
+	/* { KE_IGNORE, 0xe023, { KEY_RESERVED } }, */
+
+	/* Untested, Dell Instant Launch key on Inspiron 7520 */
+	/* { KE_IGNORE, 0xe024, { KEY_RESERVED } }, */
+
+	/* Dell Instant Launch key */
+	{ KE_KEY,    0xe025, { KEY_PROG4 } },
+
+	/* Audio panel key */
+	{ KE_IGNORE, 0xe026, { KEY_RESERVED } },
+
+	/* LCD Display On/Off Control key */
+	{ KE_KEY,    0xe027, { KEY_DISPLAYTOGGLE } },
+
+	/* Untested, Multimedia key on Dell Vostro 3560 */
+	/* { KE_IGNORE, 0xe028, { KEY_RESERVED } }, */
+
+	/* Dell Instant Launch key */
+	{ KE_KEY,    0xe029, { KEY_PROG4 } },
+
+	/* Untested, Windows Mobility Center button on Inspiron 7520 */
+	/* { KE_IGNORE, 0xe02a, { KEY_RESERVED } }, */
+
+	/* Unknown, defined in ACPI DSDT */
+	/* { KE_IGNORE, 0xe02b, { KEY_RESERVED } }, */
+
+	/* Untested, Dell Audio With Preset Switch button on Inspiron 7520 */
+	/* { KE_IGNORE, 0xe02c, { KEY_RESERVED } }, */
+
+	{ KE_IGNORE, 0xe02e, { KEY_VOLUMEDOWN } },
+	{ KE_IGNORE, 0xe030, { KEY_VOLUMEUP } },
+	{ KE_IGNORE, 0xe033, { KEY_KBDILLUMUP } },
+	{ KE_IGNORE, 0xe034, { KEY_KBDILLUMDOWN } },
+	{ KE_IGNORE, 0xe03a, { KEY_CAPSLOCK } },
+
+	/* NIC Link is Up */
+	{ KE_IGNORE, 0xe043, { KEY_RESERVED } },
+
+	/* NIC Link is Down */
+	{ KE_IGNORE, 0xe044, { KEY_RESERVED } },
+
+	/*
+	 * This entry is very suspicious!
+	 * Originally Matthew Garrett created this dell-wmi driver specially for
+	 * "button with a picture of a battery" which has event code 0xe045.
+	 * Later Mario Limonciello from Dell told us that event code 0xe045 is
+	 * reported by Num Lock and should be ignored because key is send also
+	 * by keyboard controller.
+	 * So for now we will ignore this event to prevent potential double
+	 * Num Lock key press.
+	 */
+	{ KE_IGNORE, 0xe045, { KEY_NUMLOCK } },
+
+	/* Scroll lock and also going to tablet mode on portable devices */
+	{ KE_IGNORE, 0xe046, { KEY_SCROLLLOCK } },
+
+	/* Untested, going from tablet mode on portable devices */
+	/* { KE_IGNORE, 0xe047, { KEY_RESERVED } }, */
+
+	/* Dell Support Center key */
+	{ KE_IGNORE, 0xe06e, { KEY_RESERVED } },
+
+	{ KE_IGNORE, 0xe0f7, { KEY_MUTE } },
+	{ KE_IGNORE, 0xe0f8, { KEY_VOLUMEDOWN } },
+	{ KE_IGNORE, 0xe0f9, { KEY_VOLUMEUP } },
+};
+
+struct dell_bios_keymap_entry {
+	u16 scancode;
+	u16 keycode;
+};
+
+struct dell_bios_hotkey_table {
+	struct dmi_header header;
+	struct dell_bios_keymap_entry keymap[];
+
+};
+
+struct dell_dmi_results {
+	int err;
+	int keymap_size;
+	struct key_entry *keymap;
+};
+
+/* Uninitialized entries here are KEY_RESERVED == 0. */
+static const u16 bios_to_linux_keycode[256] = {
+	[0]	= KEY_MEDIA,
+	[1]	= KEY_NEXTSONG,
+	[2]	= KEY_PLAYPAUSE,
+	[3]	= KEY_PREVIOUSSONG,
+	[4]	= KEY_STOPCD,
+	[5]	= KEY_UNKNOWN,
+	[6]	= KEY_UNKNOWN,
+	[7]	= KEY_UNKNOWN,
+	[8]	= KEY_WWW,
+	[9]	= KEY_UNKNOWN,
+	[10]	= KEY_VOLUMEDOWN,
+	[11]	= KEY_MUTE,
+	[12]	= KEY_VOLUMEUP,
+	[13]	= KEY_UNKNOWN,
+	[14]	= KEY_BATTERY,
+	[15]	= KEY_EJECTCD,
+	[16]	= KEY_UNKNOWN,
+	[17]	= KEY_SLEEP,
+	[18]	= KEY_PROG1,
+	[19]	= KEY_BRIGHTNESSDOWN,
+	[20]	= KEY_BRIGHTNESSUP,
+	[21]	= KEY_BRIGHTNESS_AUTO,
+	[22]	= KEY_KBDILLUMTOGGLE,
+	[23]	= KEY_UNKNOWN,
+	[24]	= KEY_SWITCHVIDEOMODE,
+	[25]	= KEY_UNKNOWN,
+	[26]	= KEY_UNKNOWN,
+	[27]	= KEY_SWITCHVIDEOMODE,
+	[28]	= KEY_UNKNOWN,
+	[29]	= KEY_UNKNOWN,
+	[30]	= KEY_PROG2,
+	[31]	= KEY_UNKNOWN,
+	[32]	= KEY_UNKNOWN,
+	[33]	= KEY_UNKNOWN,
+	[34]	= KEY_UNKNOWN,
+	[35]	= KEY_UNKNOWN,
+	[36]	= KEY_UNKNOWN,
+	[37]	= KEY_UNKNOWN,
+	[38]	= KEY_MICMUTE,
+	[255]	= KEY_PROG3,
+};
+
+/*
+ * Keymap for WMI events of type 0x0010
+ *
+ * These are applied if the 0xB2 DMI hotkey table is present and doesn't
+ * override them.
+ */
+static const struct key_entry dell_wmi_keymap_type_0010[] = {
+	/* Fn-lock switched to function keys */
+	{ KE_IGNORE, 0x0, { KEY_RESERVED } },
+
+	/* Fn-lock switched to multimedia keys */
+	{ KE_IGNORE, 0x1, { KEY_RESERVED } },
+
+	/* Mic mute */
+	{ KE_KEY, 0x150, { KEY_MICMUTE } },
+
+	/* Fn-lock */
+	{ KE_IGNORE, 0x151, { KEY_RESERVED } },
+
+	/* Change keyboard illumination */
+	{ KE_IGNORE, 0x152, { KEY_KBDILLUMTOGGLE } },
+
+	/*
+	 * Radio disable (notify only -- there is no model for which the
+	 * WMI event is supposed to trigger an action).
+	 */
+	{ KE_IGNORE, 0x153, { KEY_RFKILL } },
+
+	/* RGB keyboard backlight control */
+	{ KE_IGNORE, 0x154, { KEY_RESERVED } },
+
+	/*
+	 * Stealth mode toggle. This will "disable all lights and sounds".
+	 * The action is performed by the BIOS and EC; the WMI event is just
+	 * a notification. On the XPS 13 9350, this is Fn+F7, and there's
+	 * a BIOS setting to enable and disable the hotkey.
+	 */
+	{ KE_IGNORE, 0x155, { KEY_RESERVED } },
+
+	/* Rugged magnetic dock attach/detach events */
+	{ KE_IGNORE, 0x156, { KEY_RESERVED } },
+	{ KE_IGNORE, 0x157, { KEY_RESERVED } },
+
+	/* Rugged programmable (P1/P2/P3 keys) */
+	{ KE_KEY,    0x850, { KEY_PROG1 } },
+	{ KE_KEY,    0x851, { KEY_PROG2 } },
+	{ KE_KEY,    0x852, { KEY_PROG3 } },
+
+	/*
+	 * Radio disable (notify only -- there is no model for which the
+	 * WMI event is supposed to trigger an action).
+	 */
+	{ KE_IGNORE, 0xe008, { KEY_RFKILL } },
+
+	/* Fn-lock */
+	{ KE_IGNORE, 0xe035, { KEY_RESERVED } },
+};
+
+/*
+ * Keymap for WMI events of type 0x0011
+ */
+static const struct key_entry dell_wmi_keymap_type_0011[] = {
+	/* Battery unplugged */
+	{ KE_IGNORE, 0xfff0, { KEY_RESERVED } },
+
+	/* Battery inserted */
+	{ KE_IGNORE, 0xfff1, { KEY_RESERVED } },
+
+	/* Keyboard backlight level changed */
+	{ KE_IGNORE, 0x01e1, { KEY_RESERVED } },
+	{ KE_IGNORE, 0x02ea, { KEY_RESERVED } },
+	{ KE_IGNORE, 0x02eb, { KEY_RESERVED } },
+	{ KE_IGNORE, 0x02ec, { KEY_RESERVED } },
+	{ KE_IGNORE, 0x02f6, { KEY_RESERVED } },
+};
+
+static void dell_wmi_process_key(struct wmi_device *wdev, int type, int code)
+{
+	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
+	const struct key_entry *key;
+
+	key = sparse_keymap_entry_from_scancode(priv->input_dev,
+						(type << 16) | code);
+	if (!key) {
+		pr_info("Unknown key with type 0x%04x and code 0x%04x pressed\n",
+			type, code);
+		return;
+	}
+
+	pr_debug("Key with type 0x%04x and code 0x%04x pressed\n", type, code);
+
+	/* Don't report brightness notifications that will also come via ACPI */
+	if ((key->keycode == KEY_BRIGHTNESSUP ||
+	     key->keycode == KEY_BRIGHTNESSDOWN) &&
+	    acpi_video_handles_brightness_key_presses())
+		return;
+
+	if (type == 0x0000 && code == 0xe025 && !wmi_requires_smbios_request)
+		return;
+
+	if (key->keycode == KEY_KBDILLUMTOGGLE)
+		dell_laptop_call_notifier(
+			DELL_LAPTOP_KBD_BACKLIGHT_BRIGHTNESS_CHANGED, NULL);
+
+	sparse_keymap_report_entry(priv->input_dev, key, 1, true);
+}
+
+static void dell_wmi_notify(struct wmi_device *wdev,
+			    union acpi_object *obj)
+{
+	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
+	u16 *buffer_entry, *buffer_end;
+	acpi_size buffer_size;
+	int len, i;
+
+	if (obj->type != ACPI_TYPE_BUFFER) {
+		pr_warn("bad response type %x\n", obj->type);
+		return;
+	}
+
+	pr_debug("Received WMI event (%*ph)\n",
+		obj->buffer.length, obj->buffer.pointer);
+
+	buffer_entry = (u16 *)obj->buffer.pointer;
+	buffer_size = obj->buffer.length/2;
+	buffer_end = buffer_entry + buffer_size;
+
+	/*
+	 * BIOS/ACPI on devices with WMI interface version 0 does not clear
+	 * buffer before filling it. So next time when BIOS/ACPI send WMI event
+	 * which is smaller as previous then it contains garbage in buffer from
+	 * previous event.
+	 *
+	 * BIOS/ACPI on devices with WMI interface version 1 clears buffer and
+	 * sometimes send more events in buffer at one call.
+	 *
+	 * So to prevent reading garbage from buffer we will process only first
+	 * one event on devices with WMI interface version 0.
+	 */
+	if (priv->interface_version == 0 && buffer_entry < buffer_end)
+		if (buffer_end > buffer_entry + buffer_entry[0] + 1)
+			buffer_end = buffer_entry + buffer_entry[0] + 1;
+
+	while (buffer_entry < buffer_end) {
+
+		len = buffer_entry[0];
+		if (len == 0)
+			break;
+
+		len++;
+
+		if (buffer_entry + len > buffer_end) {
+			pr_warn("Invalid length of WMI event\n");
+			break;
+		}
+
+		pr_debug("Process buffer (%*ph)\n", len*2, buffer_entry);
+
+		switch (buffer_entry[1]) {
+		case 0x0000: /* One key pressed or event occurred */
+			if (len > 2)
+				dell_wmi_process_key(wdev, 0x0000,
+						     buffer_entry[2]);
+			/* Other entries could contain additional information */
+			break;
+		case 0x0010: /* Sequence of keys pressed */
+		case 0x0011: /* Sequence of events occurred */
+			for (i = 2; i < len; ++i)
+				dell_wmi_process_key(wdev, buffer_entry[1],
+						     buffer_entry[i]);
+			break;
+		default: /* Unknown event */
+			pr_info("Unknown WMI event type 0x%x\n",
+				(int)buffer_entry[1]);
+			break;
+		}
+
+		buffer_entry += len;
+
+	}
+
+}
+
+static bool have_scancode(u32 scancode, const struct key_entry *keymap, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		if (keymap[i].code == scancode)
+			return true;
+
+	return false;
+}
+
+static void handle_dmi_entry(const struct dmi_header *dm, void *opaque)
+{
+	struct dell_dmi_results *results = opaque;
+	struct dell_bios_hotkey_table *table;
+	int hotkey_num, i, pos = 0;
+	struct key_entry *keymap;
+
+	if (results->err || results->keymap)
+		return;		/* We already found the hotkey table. */
+
+	/* The Dell hotkey table is type 0xB2.  Scan until we find it. */
+	if (dm->type != 0xb2)
+		return;
+
+	table = container_of(dm, struct dell_bios_hotkey_table, header);
+
+	hotkey_num = (table->header.length -
+		      sizeof(struct dell_bios_hotkey_table)) /
+				sizeof(struct dell_bios_keymap_entry);
+	if (hotkey_num < 1) {
+		/*
+		 * Historically, dell-wmi would ignore a DMI entry of
+		 * fewer than 7 bytes.  Sizes between 4 and 8 bytes are
+		 * nonsensical (both the header and all entries are 4
+		 * bytes), so we approximate the old behavior by
+		 * ignoring tables with fewer than one entry.
+		 */
+		return;
+	}
+
+	keymap = kcalloc(hotkey_num, sizeof(struct key_entry), GFP_KERNEL);
+	if (!keymap) {
+		results->err = -ENOMEM;
+		return;
+	}
+
+	for (i = 0; i < hotkey_num; i++) {
+		const struct dell_bios_keymap_entry *bios_entry =
+					&table->keymap[i];
+
+		/* Uninitialized entries are 0 aka KEY_RESERVED. */
+		u16 keycode = (bios_entry->keycode <
+			       ARRAY_SIZE(bios_to_linux_keycode)) ?
+			bios_to_linux_keycode[bios_entry->keycode] :
+			KEY_RESERVED;
+
+		/*
+		 * Log if we find an entry in the DMI table that we don't
+		 * understand.  If this happens, we should figure out what
+		 * the entry means and add it to bios_to_linux_keycode.
+		 */
+		if (keycode == KEY_RESERVED) {
+			pr_info("firmware scancode 0x%x maps to unrecognized keycode 0x%x\n",
+				bios_entry->scancode, bios_entry->keycode);
+			continue;
+		}
+
+		if (keycode == KEY_KBDILLUMTOGGLE)
+			keymap[pos].type = KE_IGNORE;
+		else
+			keymap[pos].type = KE_KEY;
+		keymap[pos].code = bios_entry->scancode;
+		keymap[pos].keycode = keycode;
+
+		pos++;
+	}
+
+	results->keymap = keymap;
+	results->keymap_size = pos;
+}
+
+static int dell_wmi_input_setup(struct wmi_device *wdev)
+{
+	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
+	struct dell_dmi_results dmi_results = {};
+	struct key_entry *keymap;
+	int err, i, pos = 0;
+
+	priv->input_dev = input_allocate_device();
+	if (!priv->input_dev)
+		return -ENOMEM;
+
+	priv->input_dev->name = "Dell WMI hotkeys";
+	priv->input_dev->id.bustype = BUS_HOST;
+	priv->input_dev->dev.parent = &wdev->dev;
+
+	if (dmi_walk(handle_dmi_entry, &dmi_results)) {
+		/*
+		 * Historically, dell-wmi ignored dmi_walk errors.  A failure
+		 * is certainly surprising, but it probably just indicates
+		 * a very old laptop.
+		 */
+		pr_warn("no DMI; using the old-style hotkey interface\n");
+	}
+
+	if (dmi_results.err) {
+		err = dmi_results.err;
+		goto err_free_dev;
+	}
+
+	keymap = kcalloc(dmi_results.keymap_size +
+			 ARRAY_SIZE(dell_wmi_keymap_type_0000) +
+			 ARRAY_SIZE(dell_wmi_keymap_type_0010) +
+			 ARRAY_SIZE(dell_wmi_keymap_type_0011) +
+			 1,
+			 sizeof(struct key_entry), GFP_KERNEL);
+	if (!keymap) {
+		kfree(dmi_results.keymap);
+		err = -ENOMEM;
+		goto err_free_dev;
+	}
+
+	/* Append table with events of type 0x0010 which comes from DMI */
+	for (i = 0; i < dmi_results.keymap_size; i++) {
+		keymap[pos] = dmi_results.keymap[i];
+		keymap[pos].code |= (0x0010 << 16);
+		pos++;
+	}
+
+	kfree(dmi_results.keymap);
+
+	/* Append table with extra events of type 0x0010 which are not in DMI */
+	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0010); i++) {
+		const struct key_entry *entry = &dell_wmi_keymap_type_0010[i];
+
+		/*
+		 * Check if we've already found this scancode.  This takes
+		 * quadratic time, but it doesn't matter unless the list
+		 * of extra keys gets very long.
+		 */
+		if (dmi_results.keymap_size &&
+		    have_scancode(entry->code | (0x0010 << 16),
+				  keymap, dmi_results.keymap_size)
+		   )
+			continue;
+
+		keymap[pos] = *entry;
+		keymap[pos].code |= (0x0010 << 16);
+		pos++;
+	}
+
+	/* Append table with events of type 0x0011 */
+	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0011); i++) {
+		keymap[pos] = dell_wmi_keymap_type_0011[i];
+		keymap[pos].code |= (0x0011 << 16);
+		pos++;
+	}
+
+	/*
+	 * Now append also table with "legacy" events of type 0x0000. Some of
+	 * them are reported also on laptops which have scancodes in DMI.
+	 */
+	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0000); i++) {
+		keymap[pos] = dell_wmi_keymap_type_0000[i];
+		pos++;
+	}
+
+	keymap[pos].type = KE_END;
+
+	err = sparse_keymap_setup(priv->input_dev, keymap, NULL);
+	/*
+	 * Sparse keymap library makes a copy of keymap so we don't need the
+	 * original one that was allocated.
+	 */
+	kfree(keymap);
+	if (err)
+		goto err_free_dev;
+
+	err = input_register_device(priv->input_dev);
+	if (err)
+		goto err_free_dev;
+
+	return 0;
+
+ err_free_dev:
+	input_free_device(priv->input_dev);
+	return err;
+}
+
+static void dell_wmi_input_destroy(struct wmi_device *wdev)
+{
+	struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
+
+	input_unregister_device(priv->input_dev);
+}
+
+/*
+ * According to Dell SMBIOS documentation:
+ *
+ * 17  3  Application Program Registration
+ *
+ *     cbArg1 Application ID 1 = 0x00010000
+ *     cbArg2 Application ID 2
+ *            QUICKSET/DCP = 0x51534554 "QSET"
+ *            ALS Driver   = 0x416c7353 "AlsS"
+ *            Latitude ON  = 0x4c6f6e52 "LonR"
+ *     cbArg3 Application version or revision number
+ *     cbArg4 0 = Unregister application
+ *            1 = Register application
+ *     cbRes1 Standard return codes (0, -1, -2)
+ */
+
+static int dell_wmi_events_set_enabled(bool enable)
+{
+	struct calling_interface_buffer *buffer;
+	int ret;
+
+	buffer = kzalloc(sizeof(struct calling_interface_buffer), GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+	buffer->cmd_class = CLASS_INFO;
+	buffer->cmd_select = SELECT_APP_REGISTRATION;
+	buffer->input[0] = 0x10000;
+	buffer->input[1] = 0x51534554;
+	buffer->input[3] = enable;
+	ret = dell_smbios_call(buffer);
+	if (ret == 0)
+		ret = buffer->output[0];
+	kfree(buffer);
+
+	return dell_smbios_error(ret);
+}
+
+static int dell_wmi_probe(struct wmi_device *wdev)
+{
+	struct dell_wmi_priv *priv;
+	int ret;
+
+	ret = dell_wmi_get_descriptor_valid();
+	if (ret)
+		return ret;
+
+	priv = devm_kzalloc(
+		&wdev->dev, sizeof(struct dell_wmi_priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	dev_set_drvdata(&wdev->dev, priv);
+
+	if (!dell_wmi_get_interface_version(&priv->interface_version))
+		return -EPROBE_DEFER;
+
+	return dell_wmi_input_setup(wdev);
+}
+
+static int dell_wmi_remove(struct wmi_device *wdev)
+{
+	dell_wmi_input_destroy(wdev);
+	return 0;
+}
+static const struct wmi_device_id dell_wmi_id_table[] = {
+	{ .guid_string = DELL_EVENT_GUID },
+	{ },
+};
+
+static struct wmi_driver dell_wmi_driver = {
+	.driver = {
+		.name = "dell-wmi",
+	},
+	.id_table = dell_wmi_id_table,
+	.probe = dell_wmi_probe,
+	.remove = dell_wmi_remove,
+	.notify = dell_wmi_notify,
+};
+
+static int __init dell_wmi_init(void)
+{
+	int err;
+
+	dmi_check_system(dell_wmi_smbios_list);
+
+	if (wmi_requires_smbios_request) {
+		err = dell_wmi_events_set_enabled(true);
+		if (err) {
+			pr_err("Failed to enable WMI events\n");
+			return err;
+		}
+	}
+
+	return wmi_driver_register(&dell_wmi_driver);
+}
+late_initcall(dell_wmi_init);
+
+static void __exit dell_wmi_exit(void)
+{
+	if (wmi_requires_smbios_request)
+		dell_wmi_events_set_enabled(false);
+
+	wmi_driver_unregister(&dell_wmi_driver);
+}
+module_exit(dell_wmi_exit);