[mirror_ubuntu-hirsute-kernel.git] / drivers / platform / x86 / dell-wmi.c

/*
 * 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 <acpi/video.h>
#include "dell-smbios.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"
#define DELL_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492"

static u32 dell_wmi_interface_version;
static bool wmi_requires_smbios_request;

MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
MODULE_ALIAS("wmi:"DELL_DESCRIPTOR_GUID);

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 Vostro V131",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
			DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
		},
	},
	{ }
};

/*
 * 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_legacy_keymap[] __initconst = {
	{ KE_IGNORE, 0x003a, { KEY_CAPSLOCK } },

	{ KE_KEY, 0xe045, { KEY_PROG1 } },
	{ KE_KEY, 0xe009, { KEY_EJECTCD } },

	/* These also contain the brightness level at offset 6 */
	{ KE_KEY, 0xe006, { KEY_BRIGHTNESSUP } },
	{ KE_KEY, 0xe005, { KEY_BRIGHTNESSDOWN } },

	/* Battery health status button */
	{ KE_KEY, 0xe007, { KEY_BATTERY } },

	/* Radio devices state change */
	{ KE_IGNORE, 0xe008, { KEY_RFKILL } },

	/* The next device is at offset 6, the active devices are at
	   offset 8 and the attached devices at offset 10 */
	{ KE_KEY, 0xe00b, { KEY_SWITCHVIDEOMODE } },

	{ KE_IGNORE, 0xe00c, { KEY_KBDILLUMTOGGLE } },

	/* BIOS error detected */
	{ KE_IGNORE, 0xe00d, { KEY_RESERVED } },

	/* Wifi Catcher */
	{ KE_KEY, 0xe011, {KEY_PROG2 } },

	/* Ambient light sensor toggle */
	{ KE_IGNORE, 0xe013, { KEY_RESERVED } },

	{ KE_IGNORE, 0xe020, { KEY_MUTE } },

	/* Shortcut and audio panel keys */
	{ KE_KEY, 0xe025, { KEY_PROG4 } },
	{ KE_IGNORE, 0xe026, { 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 } },
	{ KE_IGNORE, 0xe045, { KEY_NUMLOCK } },
	{ KE_IGNORE, 0xe046, { KEY_SCROLLLOCK } },
	{ KE_IGNORE, 0xe0f7, { KEY_MUTE } },
	{ KE_IGNORE, 0xe0f8, { KEY_VOLUMEDOWN } },
	{ KE_IGNORE, 0xe0f9, { KEY_VOLUMEUP } },
	{ KE_END, 0 }
};

static bool dell_new_hk_type;

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;
	struct key_entry *keymap;
};

/* Uninitialized entries here are KEY_RESERVED == 0. */
static const u16 bios_to_linux_keycode[256] __initconst = {
	[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_UNKNOWN,
	[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,
};

/*
 * These are applied if the 0xB2 DMI hotkey table is present and doesn't
 * override them.
 */
static const struct key_entry dell_wmi_extra_keymap[] __initconst = {
	/* 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 */
	{ KE_IGNORE, 0x155, { KEY_RESERVED } },
};

static struct input_dev *dell_wmi_input_dev;

static void dell_wmi_process_key(int reported_key)
{
	const struct key_entry *key;

	key = sparse_keymap_entry_from_scancode(dell_wmi_input_dev,
						reported_key);
	if (!key) {
		pr_info("Unknown key with scancode 0x%x pressed\n",
			reported_key);
		return;
	}

	pr_debug("Key %x pressed\n", reported_key);

	/* 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 (reported_key == 0xe025 && !wmi_requires_smbios_request)
		return;

	sparse_keymap_report_entry(dell_wmi_input_dev, key, 1, true);
}

static void dell_wmi_notify(u32 value, void *context)
{
	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;
	acpi_status status;
	acpi_size buffer_size;
	u16 *buffer_entry, *buffer_end;
	int len, i;

	status = wmi_get_event_data(value, &response);
	if (status != AE_OK) {
		pr_warn("bad event status 0x%x\n", status);
		return;
	}

	obj = (union acpi_object *)response.pointer;
	if (!obj) {
		pr_warn("no response\n");
		return;
	}

	if (obj->type != ACPI_TYPE_BUFFER) {
		pr_warn("bad response type %x\n", obj->type);
		kfree(obj);
		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;

	if (!dell_new_hk_type) {
		if (buffer_size >= 3 && buffer_entry[1] == 0x0)
			dell_wmi_process_key(buffer_entry[2]);
		else if (buffer_size >= 2)
			dell_wmi_process_key(buffer_entry[1]);
		else
			pr_info("Received unknown WMI event\n");
		kfree(obj);
		return;
	}

	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 (dell_wmi_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 0x00:
			for (i = 2; i < len; ++i) {
				switch (buffer_entry[i]) {
				case 0xe043:
					/* NIC Link is Up */
					pr_debug("NIC Link is Up\n");
					break;
				case 0xe044:
					/* NIC Link is Down */
					pr_debug("NIC Link is Down\n");
					break;
				case 0xe045:
					/* Unknown event but defined in DSDT */
				default:
					/* Unknown event */
					pr_info("Unknown WMI event type 0x00: "
						"0x%x\n", (int)buffer_entry[i]);
					break;
				}
			}
			break;
		case 0x10:
			/* Keys pressed */
			for (i = 2; i < len; ++i)
				dell_wmi_process_key(buffer_entry[i]);
			break;
		case 0x11:
			for (i = 2; i < len; ++i) {
				switch (buffer_entry[i]) {
				case 0xfff0:
					/* Battery unplugged */
					pr_debug("Battery unplugged\n");
					break;
				case 0xfff1:
					/* Battery inserted */
					pr_debug("Battery inserted\n");
					break;
				case 0x01e1:
				case 0x02ea:
				case 0x02eb:
				case 0x02ec:
				case 0x02f6:
					/* Keyboard backlight level changed */
					pr_debug("Keyboard backlight level "
						 "changed\n");
					break;
				default:
					/* Unknown event */
					pr_info("Unknown WMI event type 0x11: "
						"0x%x\n", (int)buffer_entry[i]);
					break;
				}
			}
			break;
		default:
			/* Unknown event */
			pr_info("Unknown WMI event type 0x%x\n",
				(int)buffer_entry[1]);
			break;
		}

		buffer_entry += len;

	}

	kfree(obj);
}

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 __init 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;
	int num_bios_keys;

	if (results->err || results->keymap)
		return;		/* We already found the hotkey table. */

	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 + ARRAY_SIZE(dell_wmi_extra_keymap) + 1,
			 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++;
	}

	num_bios_keys = pos;

	for (i = 0; i < ARRAY_SIZE(dell_wmi_extra_keymap); i++) {
		const struct key_entry *entry = &dell_wmi_extra_keymap[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 (!have_scancode(entry->code, keymap, num_bios_keys)) {
			keymap[pos] = *entry;
			pos++;
		}
	}

	keymap[pos].type = KE_END;

	results->keymap = keymap;
}

static int __init dell_wmi_input_setup(void)
{
	struct dell_dmi_results dmi_results = {};
	int err;

	dell_wmi_input_dev = input_allocate_device();
	if (!dell_wmi_input_dev)
		return -ENOMEM;

	dell_wmi_input_dev->name = "Dell WMI hotkeys";
	dell_wmi_input_dev->phys = "wmi/input0";
	dell_wmi_input_dev->id.bustype = BUS_HOST;

	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;
	}

	if (dmi_results.keymap) {
		dell_new_hk_type = true;

		err = sparse_keymap_setup(dell_wmi_input_dev,
					  dmi_results.keymap, NULL);

		/*
		 * Sparse keymap library makes a copy of keymap so we
		 * don't need the original one that was allocated.
		 */
		kfree(dmi_results.keymap);
	} else {
		err = sparse_keymap_setup(dell_wmi_input_dev,
					  dell_wmi_legacy_keymap, NULL);
	}
	if (err)
		goto err_free_dev;

	err = input_register_device(dell_wmi_input_dev);
	if (err)
		goto err_free_keymap;

	return 0;

 err_free_keymap:
	sparse_keymap_free(dell_wmi_input_dev);
 err_free_dev:
	input_free_device(dell_wmi_input_dev);
	return err;
}

static void dell_wmi_input_destroy(void)
{
	sparse_keymap_free(dell_wmi_input_dev);
	input_unregister_device(dell_wmi_input_dev);
}

/*
 * Descriptor buffer is 128 byte long and contains:
 *
 *       Name             Offset  Length  Value
 * Vendor Signature          0       4    "DELL"
 * Object Signature          4       4    " WMI"
 * WMI Interface Version     8       4    <version>
 * WMI buffer length        12       4    4096
 */
static int __init dell_wmi_check_descriptor_buffer(void)
{
	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;
	acpi_status status;
	u32 *buffer;

	status = wmi_query_block(DELL_DESCRIPTOR_GUID, 0, &out);
	if (ACPI_FAILURE(status)) {
		pr_err("Cannot read Dell descriptor buffer - %d\n", status);
		return status;
	}

	obj = (union acpi_object *)out.pointer;
	if (!obj) {
		pr_err("Dell descriptor buffer is empty\n");
		return -EINVAL;
	}

	if (obj->type != ACPI_TYPE_BUFFER) {
		pr_err("Cannot read Dell descriptor buffer\n");
		kfree(obj);
		return -EINVAL;
	}

	if (obj->buffer.length != 128) {
		pr_err("Dell descriptor buffer has invalid length (%d)\n",
			obj->buffer.length);
		if (obj->buffer.length < 16) {
			kfree(obj);
			return -EINVAL;
		}
	}

	buffer = (u32 *)obj->buffer.pointer;

	if (buffer[0] != 0x4C4C4544 && buffer[1] != 0x494D5720)
		pr_warn("Dell descriptor buffer has invalid signature (%*ph)\n",
			8, buffer);

	if (buffer[2] != 0 && buffer[2] != 1)
		pr_warn("Dell descriptor buffer has unknown version (%d)\n",
			buffer[2]);

	if (buffer[3] != 4096)
		pr_warn("Dell descriptor buffer has invalid buffer length (%d)\n",
			buffer[3]);

	dell_wmi_interface_version = buffer[2];

	pr_info("Detected Dell WMI interface version %u\n",
		dell_wmi_interface_version);

	kfree(obj);
	return 0;
}

/*
 * 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 = dell_smbios_get_buffer();
	buffer->input[0] = 0x10000;
	buffer->input[1] = 0x51534554;
	buffer->input[3] = enable;
	dell_smbios_send_request(17, 3);
	ret = buffer->output[0];
	dell_smbios_release_buffer();

	return dell_smbios_error(ret);
}

static int __init dell_wmi_init(void)
{
	int err;
	acpi_status status;

	if (!wmi_has_guid(DELL_EVENT_GUID) ||
	    !wmi_has_guid(DELL_DESCRIPTOR_GUID)) {
		pr_warn("Dell WMI GUID were not found\n");
		return -ENODEV;
	}

	err = dell_wmi_check_descriptor_buffer();
	if (err)
		return err;

	err = dell_wmi_input_setup();
	if (err)
		return err;

	status = wmi_install_notify_handler(DELL_EVENT_GUID,
					 dell_wmi_notify, NULL);
	if (ACPI_FAILURE(status)) {
		dell_wmi_input_destroy();
		pr_err("Unable to register notify handler - %d\n", status);
		return -ENODEV;
	}

	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");
			wmi_remove_notify_handler(DELL_EVENT_GUID);
			dell_wmi_input_destroy();
			return err;
		}
	}

	return 0;
}
module_init(dell_wmi_init);

static void __exit dell_wmi_exit(void)
{
	if (wmi_requires_smbios_request)
		dell_wmi_events_set_enabled(false);
	wmi_remove_notify_handler(DELL_EVENT_GUID);
	dell_wmi_input_destroy();
}
module_exit(dell_wmi_exit);
Commit	Line	Data
0b3f6109 MG	1	/*
	2	* Dell WMI hotkeys
	3	*
	4	* Copyright (C) 2008 Red Hat <mjg@redhat.com>
595773a4	5	* Copyright (C) 2014-2015 Pali Rohár <pali.rohar@gmail.com>
0b3f6109 MG	6	*
	7	* Portions based on wistron_btns.c:
	8	* Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
	9	* Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
	10	* Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
	11	*
	12	* This program is free software; you can redistribute it and/or modify
	13	* it under the terms of the GNU General Public License as published by
	14	* the Free Software Foundation; either version 2 of the License, or
	15	* (at your option) any later version.
	16	*
	17	* This program is distributed in the hope that it will be useful,
	18	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	20	* GNU General Public License for more details.
	21	*
	22	* You should have received a copy of the GNU General Public License
	23	* along with this program; if not, write to the Free Software
	24	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	25	*/
	26
eb889524 JP	27	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
eb889524 JP	28
0b3f6109 MG	29	#include <linux/kernel.h>
	30	#include <linux/module.h>
	31	#include <linux/init.h>
5a0e3ad6	32	#include <linux/slab.h>
0b3f6109 MG	33	#include <linux/types.h>
0b3f6109 MG	34	#include <linux/input.h>
890a7c8e	35	#include <linux/input/sparse-keymap.h>
0b3f6109 MG	36	#include <linux/acpi.h>
0b3f6109 MG	37	#include <linux/string.h>
5ea25597	38	#include <linux/dmi.h>
18bd7696	39	#include <acpi/video.h>
e09c4d5b	40	#include "dell-smbios.h"
0b3f6109 MG	41
0b3f6109 MG	42	MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
595773a4	43	MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
0b3f6109 MG	44	MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver");
	45	MODULE_LICENSE("GPL");
	46
	47	#define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"
595773a4	48	#define DELL_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492"
0b3f6109	49
595773a4	50	static u32 dell_wmi_interface_version;
e09c4d5b	51	static bool wmi_requires_smbios_request;
0b3f6109 MG	52
0b3f6109 MG	53	MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
595773a4	54	MODULE_ALIAS("wmi:"DELL_DESCRIPTOR_GUID);
0b3f6109	55
e09c4d5b MK	56	static int __init dmi_matched(const struct dmi_system_id *dmi)
	57	{
	58	wmi_requires_smbios_request = 1;
	59	return 1;
	60	}
	61
	62	static const struct dmi_system_id dell_wmi_smbios_list[] __initconst = {
	63	{
	64	.callback = dmi_matched,
	65	.ident = "Dell Vostro V131",
	66	.matches = {
	67	DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
	68	DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
	69	},
	70	},
	71	{ }
	72	};
	73
5cab0098 ML	74	/*
	75	* Certain keys are flagged as KE_IGNORE. All of these are either
	76	* notifications (rather than requests for change) or are also sent
	77	* via the keyboard controller so should not be sent again.
	78	*/
0b3f6109	79
890a7c8e	80	static const struct key_entry dell_wmi_legacy_keymap[] __initconst = {
f1566f0d SF	81	{ KE_IGNORE, 0x003a, { KEY_CAPSLOCK } },
f1566f0d SF	82
890a7c8e DT	83	{ KE_KEY, 0xe045, { KEY_PROG1 } },
890a7c8e DT	84	{ KE_KEY, 0xe009, { KEY_EJECTCD } },
5cab0098 ML	85
5cab0098 ML	86	/* These also contain the brightness level at offset 6 */
890a7c8e DT	87	{ KE_KEY, 0xe006, { KEY_BRIGHTNESSUP } },
890a7c8e DT	88	{ KE_KEY, 0xe005, { KEY_BRIGHTNESSDOWN } },
5cab0098 ML	89
5cab0098 ML	90	/* Battery health status button */
890a7c8e	91	{ KE_KEY, 0xe007, { KEY_BATTERY } },
5cab0098	92
8f8d75eb GM	93	/* Radio devices state change */
8f8d75eb GM	94	{ KE_IGNORE, 0xe008, { KEY_RFKILL } },
5cab0098 ML	95
	96	/* The next device is at offset 6, the active devices are at
	97	offset 8 and the attached devices at offset 10 */
890a7c8e	98	{ KE_KEY, 0xe00b, { KEY_SWITCHVIDEOMODE } },
5cab0098	99
890a7c8e	100	{ KE_IGNORE, 0xe00c, { KEY_KBDILLUMTOGGLE } },
5cab0098 ML	101
5cab0098 ML	102	/* BIOS error detected */
890a7c8e	103	{ KE_IGNORE, 0xe00d, { KEY_RESERVED } },
5cab0098 ML	104
5cab0098 ML	105	/* Wifi Catcher */
890a7c8e	106	{ KE_KEY, 0xe011, {KEY_PROG2 } },
5cab0098 ML	107
5cab0098 ML	108	/* Ambient light sensor toggle */
890a7c8e DT	109	{ KE_IGNORE, 0xe013, { KEY_RESERVED } },
	110
	111	{ KE_IGNORE, 0xe020, { KEY_MUTE } },
f1566f0d SF	112
f1566f0d SF	113	/* Shortcut and audio panel keys */
13f5059a	114	{ KE_KEY, 0xe025, { KEY_PROG4 } },
f1566f0d SF	115	{ KE_IGNORE, 0xe026, { KEY_RESERVED } },
f1566f0d SF	116
890a7c8e DT	117	{ KE_IGNORE, 0xe02e, { KEY_VOLUMEDOWN } },
	118	{ KE_IGNORE, 0xe030, { KEY_VOLUMEUP } },
	119	{ KE_IGNORE, 0xe033, { KEY_KBDILLUMUP } },
	120	{ KE_IGNORE, 0xe034, { KEY_KBDILLUMDOWN } },
	121	{ KE_IGNORE, 0xe03a, { KEY_CAPSLOCK } },
	122	{ KE_IGNORE, 0xe045, { KEY_NUMLOCK } },
	123	{ KE_IGNORE, 0xe046, { KEY_SCROLLLOCK } },
f1566f0d SF	124	{ KE_IGNORE, 0xe0f7, { KEY_MUTE } },
	125	{ KE_IGNORE, 0xe0f8, { KEY_VOLUMEDOWN } },
	126	{ KE_IGNORE, 0xe0f9, { KEY_VOLUMEUP } },
890a7c8e	127	{ KE_END, 0 }
0b3f6109 MG	128	};
0b3f6109 MG	129
5ea25597 RK	130	static bool dell_new_hk_type;
5ea25597 RK	131
890a7c8e	132	struct dell_bios_keymap_entry {
5ea25597 RK	133	u16 scancode;
	134	u16 keycode;
	135	};
	136
890a7c8e	137	struct dell_bios_hotkey_table {
5ea25597	138	struct dmi_header header;
890a7c8e	139	struct dell_bios_keymap_entry keymap[];
5ea25597 RK	140
	141	};
	142
18b6f80f AL	143	struct dell_dmi_results {
	144	int err;
	145	struct key_entry *keymap;
	146	};
5ea25597	147
cbc61f11	148	/* Uninitialized entries here are KEY_RESERVED == 0. */
890a7c8e	149	static const u16 bios_to_linux_keycode[256] __initconst = {
394cb778 AL	150	[0] = KEY_MEDIA,
	151	[1] = KEY_NEXTSONG,
	152	[2] = KEY_PLAYPAUSE,
	153	[3] = KEY_PREVIOUSSONG,
	154	[4] = KEY_STOPCD,
	155	[5] = KEY_UNKNOWN,
	156	[6] = KEY_UNKNOWN,
	157	[7] = KEY_UNKNOWN,
	158	[8] = KEY_WWW,
	159	[9] = KEY_UNKNOWN,
	160	[10] = KEY_VOLUMEDOWN,
	161	[11] = KEY_MUTE,
	162	[12] = KEY_VOLUMEUP,
	163	[13] = KEY_UNKNOWN,
	164	[14] = KEY_BATTERY,
	165	[15] = KEY_EJECTCD,
	166	[16] = KEY_UNKNOWN,
	167	[17] = KEY_SLEEP,
	168	[18] = KEY_PROG1,
	169	[19] = KEY_BRIGHTNESSDOWN,
	170	[20] = KEY_BRIGHTNESSUP,
	171	[21] = KEY_UNKNOWN,
	172	[22] = KEY_KBDILLUMTOGGLE,
	173	[23] = KEY_UNKNOWN,
	174	[24] = KEY_SWITCHVIDEOMODE,
	175	[25] = KEY_UNKNOWN,
	176	[26] = KEY_UNKNOWN,
	177	[27] = KEY_SWITCHVIDEOMODE,
	178	[28] = KEY_UNKNOWN,
	179	[29] = KEY_UNKNOWN,
	180	[30] = KEY_PROG2,
	181	[31] = KEY_UNKNOWN,
	182	[32] = KEY_UNKNOWN,
	183	[33] = KEY_UNKNOWN,
	184	[34] = KEY_UNKNOWN,
	185	[35] = KEY_UNKNOWN,
	186	[36] = KEY_UNKNOWN,
	187	[37] = KEY_UNKNOWN,
	188	[38] = KEY_MICMUTE,
	189	[255] = KEY_PROG3,
5ea25597 RK	190	};
5ea25597 RK	191
a464afb9 AL	192	/*
	193	* These are applied if the 0xB2 DMI hotkey table is present and doesn't
	194	* override them.
	195	*/
	196	static const struct key_entry dell_wmi_extra_keymap[] __initconst = {
	197	/* Fn-lock */
	198	{ KE_IGNORE, 0x151, { KEY_RESERVED } },
	199
	200	/* Change keyboard illumination */
	201	{ KE_IGNORE, 0x152, { KEY_KBDILLUMTOGGLE } },
	202
	203	/*
	204	* Radio disable (notify only -- there is no model for which the
	205	* WMI event is supposed to trigger an action).
	206	*/
	207	{ KE_IGNORE, 0x153, { KEY_RFKILL } },
	208
	209	/* RGB keyboard backlight control */
	210	{ KE_IGNORE, 0x154, { KEY_RESERVED } },
	211
	212	/* Stealth mode toggle */
	213	{ KE_IGNORE, 0x155, { KEY_RESERVED } },
	214	};
	215
0b3f6109 MG	216	static struct input_dev *dell_wmi_input_dev;
0b3f6109 MG	217
83fc44c3 PR	218	static void dell_wmi_process_key(int reported_key)
	219	{
	220	const struct key_entry *key;
	221
	222	key = sparse_keymap_entry_from_scancode(dell_wmi_input_dev,
	223	reported_key);
	224	if (!key) {
cbc61f11 AL	225	pr_info("Unknown key with scancode 0x%x pressed\n",
cbc61f11 AL	226	reported_key);
83fc44c3 PR	227	return;
	228	}
	229
	230	pr_debug("Key %x pressed\n", reported_key);
	231
	232	/* Don't report brightness notifications that will also come via ACPI */
	233	if ((key->keycode == KEY_BRIGHTNESSUP \|\|
61679c72 HG	234	key->keycode == KEY_BRIGHTNESSDOWN) &&
61679c72 HG	235	acpi_video_handles_brightness_key_presses())
83fc44c3 PR	236	return;
83fc44c3 PR	237
13f5059a MK	238	if (reported_key == 0xe025 && !wmi_requires_smbios_request)
	239	return;
	240
83fc44c3 PR	241	sparse_keymap_report_entry(dell_wmi_input_dev, key, 1, true);
	242	}
	243
0b3f6109 MG	244	static void dell_wmi_notify(u32 value, void *context)
	245	{
	246	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
0b3f6109	247	union acpi_object *obj;
fda11e61	248	acpi_status status;
83fc44c3 PR	249	acpi_size buffer_size;
	250	u16 buffer_entry, buffer_end;
	251	int len, i;
0b3f6109	252
fda11e61 LB	253	status = wmi_get_event_data(value, &response);
fda11e61 LB	254	if (status != AE_OK) {
83fc44c3	255	pr_warn("bad event status 0x%x\n", status);
fda11e61 LB	256	return;
fda11e61 LB	257	}
0b3f6109 MG	258
0b3f6109 MG	259	obj = (union acpi_object *)response.pointer;
83fc44c3 PR	260	if (!obj) {
	261	pr_warn("no response\n");
	262	return;
	263	}
0b3f6109	264
83fc44c3 PR	265	if (obj->type != ACPI_TYPE_BUFFER) {
	266	pr_warn("bad response type %x\n", obj->type);
	267	kfree(obj);
	268	return;
	269	}
	270
	271	pr_debug("Received WMI event (%*ph)\n",
	272	obj->buffer.length, obj->buffer.pointer);
5ea25597	273
83fc44c3 PR	274	buffer_entry = (u16 *)obj->buffer.pointer;
	275	buffer_size = obj->buffer.length/2;
	276
	277	if (!dell_new_hk_type) {
	278	if (buffer_size >= 3 && buffer_entry[1] == 0x0)
	279	dell_wmi_process_key(buffer_entry[2]);
a666b6ff	280	else if (buffer_size >= 2)
83fc44c3 PR	281	dell_wmi_process_key(buffer_entry[1]);
83fc44c3 PR	282	else
a666b6ff	283	pr_info("Received unknown WMI event\n");
83fc44c3 PR	284	kfree(obj);
	285	return;
	286	}
	287
	288	buffer_end = buffer_entry + buffer_size;
	289
481fe5be PR	290	/*
	291	* BIOS/ACPI on devices with WMI interface version 0 does not clear
	292	* buffer before filling it. So next time when BIOS/ACPI send WMI event
	293	* which is smaller as previous then it contains garbage in buffer from
	294	* previous event.
	295	*
	296	* BIOS/ACPI on devices with WMI interface version 1 clears buffer and
	297	* sometimes send more events in buffer at one call.
	298	*
	299	* So to prevent reading garbage from buffer we will process only first
	300	* one event on devices with WMI interface version 0.
	301	*/
	302	if (dell_wmi_interface_version == 0 && buffer_entry < buffer_end)
	303	if (buffer_end > buffer_entry + buffer_entry[0] + 1)
	304	buffer_end = buffer_entry + buffer_entry[0] + 1;
	305
83fc44c3 PR	306	while (buffer_entry < buffer_end) {
	307
	308	len = buffer_entry[0];
	309	if (len == 0)
	310	break;
	311
	312	len++;
	313
	314	if (buffer_entry + len > buffer_end) {
	315	pr_warn("Invalid length of WMI event\n");
	316	break;
a666b6ff	317	}
5ea25597	318
83fc44c3 PR	319	pr_debug("Process buffer (%ph)\n", len2, buffer_entry);
	320
	321	switch (buffer_entry[1]) {
	322	case 0x00:
	323	for (i = 2; i < len; ++i) {
	324	switch (buffer_entry[i]) {
	325	case 0xe043:
	326	/* NIC Link is Up */
	327	pr_debug("NIC Link is Up\n");
	328	break;
	329	case 0xe044:
	330	/* NIC Link is Down */
	331	pr_debug("NIC Link is Down\n");
	332	break;
	333	case 0xe045:
	334	/* Unknown event but defined in DSDT */
	335	default:
	336	/* Unknown event */
	337	pr_info("Unknown WMI event type 0x00: "
	338	"0x%x\n", (int)buffer_entry[i]);
	339	break;
	340	}
	341	}
	342	break;
	343	case 0x10:
	344	/* Keys pressed */
	345	for (i = 2; i < len; ++i)
	346	dell_wmi_process_key(buffer_entry[i]);
	347	break;
	348	case 0x11:
	349	for (i = 2; i < len; ++i) {
	350	switch (buffer_entry[i]) {
	351	case 0xfff0:
	352	/* Battery unplugged */
	353	pr_debug("Battery unplugged\n");
	354	break;
	355	case 0xfff1:
	356	/* Battery inserted */
	357	pr_debug("Battery inserted\n");
	358	break;
	359	case 0x01e1:
	360	case 0x02ea:
	361	case 0x02eb:
	362	case 0x02ec:
	363	case 0x02f6:
	364	/* Keyboard backlight level changed */
	365	pr_debug("Keyboard backlight level "
	366	"changed\n");
	367	break;
	368	default:
	369	/* Unknown event */
	370	pr_info("Unknown WMI event type 0x11: "
	371	"0x%x\n", (int)buffer_entry[i]);
	372	break;
	373	}
	374	}
	375	break;
	376	default:
	377	/* Unknown event */
	378	pr_info("Unknown WMI event type 0x%x\n",
	379	(int)buffer_entry[1]);
	380	break;
5ea25597	381	}
83fc44c3 PR	382
	383	buffer_entry += len;
	384
0b3f6109	385	}
83fc44c3	386
3e9b988e	387	kfree(obj);
0b3f6109 MG	388	}
0b3f6109 MG	389
a464afb9 AL	390	static bool have_scancode(u32 scancode, const struct key_entry *keymap, int len)
	391	{
	392	int i;
	393
	394	for (i = 0; i < len; i++)
	395	if (keymap[i].code == scancode)
	396	return true;
	397
	398	return false;
	399	}
	400
18b6f80f	401	static void __init handle_dmi_entry(const struct dmi_header *dm,
a464afb9	402
18b6f80f	403	void *opaque)
a464afb9	404
5ea25597	405	{
18b6f80f AL	406	struct dell_dmi_results *results = opaque;
18b6f80f AL	407	struct dell_bios_hotkey_table *table;
a464afb9	408	int hotkey_num, i, pos = 0;
890a7c8e	409	struct key_entry *keymap;
a464afb9	410	int num_bios_keys;
18b6f80f AL	411
	412	if (results->err \|\| results->keymap)
	413	return; /* We already found the hotkey table. */
	414
b13de701	415	if (dm->type != 0xb2)
18b6f80f AL	416	return;
	417
	418	table = container_of(dm, struct dell_bios_hotkey_table, header);
	419
b13de701 AL	420	hotkey_num = (table->header.length -
b13de701 AL	421	sizeof(struct dell_bios_hotkey_table)) /
18b6f80f	422	sizeof(struct dell_bios_keymap_entry);
b13de701 AL	423	if (hotkey_num < 1) {
	424	/*
	425	* Historically, dell-wmi would ignore a DMI entry of
	426	* fewer than 7 bytes. Sizes between 4 and 8 bytes are
	427	* nonsensical (both the header and all entries are 4
	428	* bytes), so we approximate the old behavior by
	429	* ignoring tables with fewer than one entry.
	430	*/
	431	return;
	432	}
5ea25597	433
a464afb9 AL	434	keymap = kcalloc(hotkey_num + ARRAY_SIZE(dell_wmi_extra_keymap) + 1,
a464afb9 AL	435	sizeof(struct key_entry), GFP_KERNEL);
18b6f80f AL	436	if (!keymap) {
	437	results->err = -ENOMEM;
	438	return;
	439	}
5ea25597 RK	440
5ea25597 RK	441	for (i = 0; i < hotkey_num; i++) {
890a7c8e	442	const struct dell_bios_keymap_entry *bios_entry =
18b6f80f	443	&table->keymap[i];
cbc61f11 AL	444
	445	/* Uninitialized entries are 0 aka KEY_RESERVED. */
	446	u16 keycode = (bios_entry->keycode <
	447	ARRAY_SIZE(bios_to_linux_keycode)) ?
	448	bios_to_linux_keycode[bios_entry->keycode] :
	449	KEY_RESERVED;
	450
	451	/*
	452	* Log if we find an entry in the DMI table that we don't
	453	* understand. If this happens, we should figure out what
	454	* the entry means and add it to bios_to_linux_keycode.
	455	*/
	456	if (keycode == KEY_RESERVED) {
	457	pr_info("firmware scancode 0x%x maps to unrecognized keycode 0x%x\n",
	458	bios_entry->scancode, bios_entry->keycode);
	459	continue;
	460	}
8cb8e63b GM	461
8cb8e63b GM	462	if (keycode == KEY_KBDILLUMTOGGLE)
a464afb9	463	keymap[pos].type = KE_IGNORE;
8cb8e63b	464	else
a464afb9 AL	465	keymap[pos].type = KE_KEY;
	466	keymap[pos].code = bios_entry->scancode;
	467	keymap[pos].keycode = keycode;
	468
	469	pos++;
	470	}
	471
	472	num_bios_keys = pos;
	473
	474	for (i = 0; i < ARRAY_SIZE(dell_wmi_extra_keymap); i++) {
	475	const struct key_entry *entry = &dell_wmi_extra_keymap[i];
	476
	477	/*
	478	* Check if we've already found this scancode. This takes
	479	* quadratic time, but it doesn't matter unless the list
	480	* of extra keys gets very long.
	481	*/
	482	if (!have_scancode(entry->code, keymap, num_bios_keys)) {
	483	keymap[pos] = *entry;
	484	pos++;
	485	}
5ea25597 RK	486	}
5ea25597 RK	487
a464afb9	488	keymap[pos].type = KE_END;
5ea25597	489
18b6f80f	490	results->keymap = keymap;
5ea25597 RK	491	}
5ea25597 RK	492
0b3f6109 MG	493	static int __init dell_wmi_input_setup(void)
0b3f6109 MG	494	{
18b6f80f	495	struct dell_dmi_results dmi_results = {};
0b3f6109 MG	496	int err;
	497
	498	dell_wmi_input_dev = input_allocate_device();
0b3f6109 MG	499	if (!dell_wmi_input_dev)
	500	return -ENOMEM;
	501
	502	dell_wmi_input_dev->name = "Dell WMI hotkeys";
	503	dell_wmi_input_dev->phys = "wmi/input0";
	504	dell_wmi_input_dev->id.bustype = BUS_HOST;
890a7c8e	505
18b6f80f AL	506	if (dmi_walk(handle_dmi_entry, &dmi_results)) {
	507	/*
	508	* Historically, dell-wmi ignored dmi_walk errors. A failure
	509	* is certainly surprising, but it probably just indicates
	510	* a very old laptop.
	511	*/
	512	pr_warn("no DMI; using the old-style hotkey interface\n");
	513	}
	514
	515	if (dmi_results.err) {
	516	err = dmi_results.err;
	517	goto err_free_dev;
	518	}
	519
	520	if (dmi_results.keymap) {
	521	dell_new_hk_type = true;
0b3f6109	522
18b6f80f AL	523	err = sparse_keymap_setup(dell_wmi_input_dev,
18b6f80f AL	524	dmi_results.keymap, NULL);
0b3f6109	525
890a7c8e DT	526	/*
	527	* Sparse keymap library makes a copy of keymap so we
	528	* don't need the original one that was allocated.
	529	*/
18b6f80f	530	kfree(dmi_results.keymap);
890a7c8e DT	531	} else {
	532	err = sparse_keymap_setup(dell_wmi_input_dev,
	533	dell_wmi_legacy_keymap, NULL);
0b3f6109	534	}
890a7c8e DT	535	if (err)
	536	goto err_free_dev;
	537
	538	err = input_register_device(dell_wmi_input_dev);
	539	if (err)
	540	goto err_free_keymap;
0b3f6109 MG	541
0b3f6109 MG	542	return 0;
890a7c8e DT	543
	544	err_free_keymap:
	545	sparse_keymap_free(dell_wmi_input_dev);
	546	err_free_dev:
	547	input_free_device(dell_wmi_input_dev);
	548	return err;
	549	}
	550
	551	static void dell_wmi_input_destroy(void)
	552	{
	553	sparse_keymap_free(dell_wmi_input_dev);
	554	input_unregister_device(dell_wmi_input_dev);
	555	}
	556
595773a4 PR	557	/*
	558	* Descriptor buffer is 128 byte long and contains:
	559	*
	560	* Name Offset Length Value
	561	* Vendor Signature 0 4 "DELL"
	562	* Object Signature 4 4 " WMI"
	563	* WMI Interface Version 8 4 <version>
	564	* WMI buffer length 12 4 4096
	565	*/
	566	static int __init dell_wmi_check_descriptor_buffer(void)
	567	{
	568	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
	569	union acpi_object *obj;
	570	acpi_status status;
	571	u32 *buffer;
	572
	573	status = wmi_query_block(DELL_DESCRIPTOR_GUID, 0, &out);
	574	if (ACPI_FAILURE(status)) {
	575	pr_err("Cannot read Dell descriptor buffer - %d\n", status);
	576	return status;
	577	}
	578
	579	obj = (union acpi_object *)out.pointer;
	580	if (!obj) {
	581	pr_err("Dell descriptor buffer is empty\n");
	582	return -EINVAL;
	583	}
	584
	585	if (obj->type != ACPI_TYPE_BUFFER) {
	586	pr_err("Cannot read Dell descriptor buffer\n");
	587	kfree(obj);
	588	return -EINVAL;
	589	}
	590
	591	if (obj->buffer.length != 128) {
	592	pr_err("Dell descriptor buffer has invalid length (%d)\n",
	593	obj->buffer.length);
	594	if (obj->buffer.length < 16) {
	595	kfree(obj);
	596	return -EINVAL;
	597	}
	598	}
	599
	600	buffer = (u32 *)obj->buffer.pointer;
	601
	602	if (buffer[0] != 0x4C4C4544 && buffer[1] != 0x494D5720)
	603	pr_warn("Dell descriptor buffer has invalid signature (%*ph)\n",
	604	8, buffer);
	605
	606	if (buffer[2] != 0 && buffer[2] != 1)
	607	pr_warn("Dell descriptor buffer has unknown version (%d)\n",
	608	buffer[2]);
	609
	610	if (buffer[3] != 4096)
	611	pr_warn("Dell descriptor buffer has invalid buffer length (%d)\n",
	612	buffer[3]);
	613
	614	dell_wmi_interface_version = buffer[2];
	615
	616	pr_info("Detected Dell WMI interface version %u\n",
	617	dell_wmi_interface_version);
	618
	619	kfree(obj);
	620	return 0;
621	}
622
e09c4d5b MK	623	/*
	624	* According to Dell SMBIOS documentation:
	625	*
	626	* 17 3 Application Program Registration
	627	*
	628	* cbArg1 Application ID 1 = 0x00010000
	629	* cbArg2 Application ID 2
	630	* QUICKSET/DCP = 0x51534554 "QSET"
	631	* ALS Driver = 0x416c7353 "AlsS"
	632	* Latitude ON = 0x4c6f6e52 "LonR"
	633	* cbArg3 Application version or revision number
	634	* cbArg4 0 = Unregister application
	635	* 1 = Register application
	636	* cbRes1 Standard return codes (0, -1, -2)
	637	*/
	638
	639	static int dell_wmi_events_set_enabled(bool enable)
	640	{
	641	struct calling_interface_buffer *buffer;
	642	int ret;
	643
	644	buffer = dell_smbios_get_buffer();
	645	buffer->input[0] = 0x10000;
	646	buffer->input[1] = 0x51534554;
	647	buffer->input[3] = enable;
	648	dell_smbios_send_request(17, 3);
	649	ret = buffer->output[0];
	650	dell_smbios_release_buffer();
	651
	652	return dell_smbios_error(ret);
	653	}
	654
0b3f6109 MG	655	static int __init dell_wmi_init(void)
	656	{
	657	int err;
abb631bf	658	acpi_status status;
0b3f6109	659
595773a4 PR	660	if (!wmi_has_guid(DELL_EVENT_GUID) \|\|
	661	!wmi_has_guid(DELL_DESCRIPTOR_GUID)) {
	662	pr_warn("Dell WMI GUID were not found\n");
1fdd407f DT	663	return -ENODEV;
1fdd407f DT	664	}
5ea25597	665
595773a4 PR	666	err = dell_wmi_check_descriptor_buffer();
	667	if (err)
	668	return err;
	669
1fdd407f	670	err = dell_wmi_input_setup();
890a7c8e	671	if (err)
1fdd407f	672	return err;
5ea25597	673
abb631bf	674	status = wmi_install_notify_handler(DELL_EVENT_GUID,
1fdd407f	675	dell_wmi_notify, NULL);
abb631bf	676	if (ACPI_FAILURE(status)) {
890a7c8e	677	dell_wmi_input_destroy();
eb889524	678	pr_err("Unable to register notify handler - %d\n", status);
abb631bf	679	return -ENODEV;
1fdd407f	680	}
0b3f6109	681
e09c4d5b MK	682	dmi_check_system(dell_wmi_smbios_list);
	683
	684	if (wmi_requires_smbios_request) {
	685	err = dell_wmi_events_set_enabled(true);
	686	if (err) {
	687	pr_err("Failed to enable WMI events\n");
	688	wmi_remove_notify_handler(DELL_EVENT_GUID);
	689	dell_wmi_input_destroy();
	690	return err;
	691	}
	692	}
	693
0b3f6109 MG	694	return 0;
0b3f6109 MG	695	}
890a7c8e	696	module_init(dell_wmi_init);
0b3f6109 MG	697
	698	static void __exit dell_wmi_exit(void)
	699	{
e09c4d5b MK	700	if (wmi_requires_smbios_request)
e09c4d5b MK	701	dell_wmi_events_set_enabled(false);
1fdd407f	702	wmi_remove_notify_handler(DELL_EVENT_GUID);
890a7c8e	703	dell_wmi_input_destroy();
0b3f6109	704	}
0b3f6109	705	module_exit(dell_wmi_exit);