Re: [PATCH v8 1/2] platform/x86: dell-privacy: Add support for Dell hardware privacy

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 5/26/21 7:54 AM, Yuan, Perry wrote:
> Hi Hans.
> 
>> -----Original Message-----
>> From: Hans de Goede <hdegoede@redhat.com>
>> Sent: 2021年5月25日 20:42
>> To: Yuan, Perry; pobrn@protonmail.com; pierre-
>> louis.bossart@linux.intel.com; oder_chiou@realtek.com; perex@perex.cz;
>> tiwai@suse.com; mgross@linux.intel.com
>> Cc: lgirdwood@gmail.com; broonie@kernel.org; alsa-devel@alsa-project.org;
>> linux-kernel@vger.kernel.org; platform-driver-x86@vger.kernel.org;
>> mario.limonciello@outlook.com; Dell Client Kernel
>> Subject: Re: [PATCH v8 1/2] platform/x86: dell-privacy: Add support for Dell
>> hardware privacy
>>
>>
>> [EXTERNAL EMAIL]
>>
>> Hi Perry,
>>
>> On 5/20/21 2:16 PM, Hans de Goede wrote:
>>> Hi Perry,
>>>
>>> On 5/18/21 3:02 PM, Hans de Goede wrote:
>>>> Hi Perry,
>>>>
>>>> On 5/6/21 1:56 PM, Perry Yuan wrote:
>>>>> From: Perry Yuan <perry_yuan@dell.com>
>>>>>
>>>>> add support for Dell privacy driver for the Dell units equipped
>>>>> hardware privacy design, which protect users privacy of audio and
>>>>> camera from hardware level. Once the audio or camera privacy mode
>>>>> activated, any applications will not get any audio or video stream
>>>>> when user pressed ctrl+F4 hotkey, audio privacy mode will be
>>>>> enabled, micmute led will be also changed accordingly The micmute
>>>>> led is fully controlled by hardware & EC(embedded controller) and
>>>>> camera mute hotkey is Ctrl+F9. Currently design only emits
>>>>> SW_CAMERA_LENS_COVER event while the camera lens shutter will be
>>>>> changed by EC & HW(hardware) control
>>>>>
>>>>> *The flow is like this:
>>>>> 1) User presses key. HW does stuff with this key (timeout timer is
>>>>> started)
>>>>> 2) WMI event is emitted from BIOS to kernel
>>>>> 3) WMI event is received by dell-privacy
>>>>> 4) KEY_MICMUTE emitted from dell-privacy
>>>>> 5) Userland picks up key and modifies kcontrol for SW mute
>>>>> 6) Codec kernel driver catches and calls ledtrig_audio_set, like this:
>>>>>    ledtrig_audio_set(LED_AUDIO_MICMUTE, rt715->micmute_led ?
>> LED_ON
>>>>> :LED_OFF);
>>>>> 7) If "LED" is set to on dell-privacy notifies EC, and timeout is cancelled,
>>>>>    HW mic mute activated. If EC not notified, HW mic mute will also be
>>>>>    activated when timeout used up, it is just later than active ack
>>>>>
>>>>> Signed-off-by: Perry Yuan <perry_yuan@dell.com>
>>>>>
>>>>> ---
>>>>> v7 -> v8:
>>>>> * addressed feedback from Hans
>>>>> * use sysfs_emit_at in the sysfs attributes
>>>>> * Update Kconfig
>>>>> * improve led_classdev_unregister logic in dell-laptop
>>>>
>>>> Thank you, this version looks good to me, with the exception of then
>>>> issue with e.g. dell-wmi being builtin vs dell-privacy being a module
>>>> which will lead to the kernel not compiling.
>>>>
>>>> I've implemented the fix which I described/suggested in the
>>>> discussion about this in the v7 thread.
>>>>
>>>> I've attached 4 patches:
>>>>
>>>> [PATCH 1/4] platform/x86: dell-wmi: Rename dell-wmi.c to
>>>> dell-wmi-base.c -This is a preparation patch for the Makefile +
>>>> Kconfig changes suggested  in the v7 email thread [PATCH 2/4]
>>>> platform/x86: dell-privacy: Add support for Dell hardware privacy
>>>> -This is your v8 patch (without any changes) [PATCH 3/4] FIXUP
>>>> platform/x86: dell-privacy: Add support for Dell hardware privacy
>>>> -This implements the discussed Makefile + Kconfig changes, as well as
>>>> renaming dell-privacy-wmi.? to dell-wmi-privacy.? to because the
>>>> privacy  code now is a part of the dell-wmi module [PATCH 4/4] FIXUP
>>>> platform/x86: dell-privacy: Add support for Dell hardware privacy
>>>> -Some small changes from reviewing v8
>>>>
>>>> I've also pushed these 4 to my review-hans branch. Perry, if you can
>>>> let me know if the suggested changes in the 2 FIXUP patches are ok
>>>> with you then I'll squash them into the 2/4 patch (so that only 1/2
>>>> and 2/2 remain) and then push this to for-next.
>>>
>>> Perry, can you please let me know if you are ok with the changes from
>>> the 2 FIXME follow up patches which I attached to my previous email
>>> and which are also in the pdx86/review-hans branch ?
>>>
>>> I would like to ge this merged and I'm waiting for your ack for this.
>>
>> Ping? Can I get a reaction to this please. If you are busy with some other things
>> and need some time, that is fine, but please let me know.
>>
>> Regards,
>>
>> Hans
> 
> Thanks a lot for your support.
> The patches looks better.
> Please help to get them merged in your review branch.
> Acked.

Thanks, I've squashed the fixes into the original patch and pushed this
to pdx86/for-next now.

Regards,

Hans




>>>>> v6 -> v7:
>>>>> * addressed feedback from Hans
>>>>> * addressed feedback from Pierre
>>>>> * optimize some debug format with dev_dbg()
>>>>> v5 -> v6:
>>>>> * remove platform driver,combined privacy acpi driver into single wmi
>>>>>   driver file
>>>>> * optimize sysfs interface with string added to be more clearly
>>>>> reading
>>>>> * remove unused function and clear header file
>>>>> v4 -> v5:
>>>>> * addressed feedback from Randy Dunlap
>>>>> * addressed feedback from Pierre-Louis Bossart
>>>>> * rebase to latest 5.12 rc4 upstream kernel
>>>>> * fix some space alignment problem
>>>>> v3 -> v4:
>>>>> * fix format for Kconfig
>>>>> * add sysfs document
>>>>> * add flow comments to the privacy wmi/acpi driver
>>>>> * addressed feedback from Barnabás Pőcze[Thanks very much]
>>>>> * export privacy_valid to make the global state simpler to query
>>>>> * fix one issue which will block the dell-laptop driver to load when
>>>>>   privacy driver invalid
>>>>> * addressed feedback from Pierre-Louis Bossart,remove the EC ID
>>>>> match
>>>>> v2 -> v3:
>>>>> * add sysfs attributes doc
>>>>> v1 -> v2:
>>>>> * query EC handle from EC driver directly.
>>>>> * fix some code style.
>>>>> * add KEY_END to keymap array.
>>>>> * clean platform device when cleanup called
>>>>> * use hexadecimal format for log print in dev_dbg
>>>>> * remove __set_bit for the report keys from probe.
>>>>> * fix keymap leak
>>>>> * add err_free_keymap in dell_privacy_wmi_probe
>>>>> * wmi driver will be unregistered if privacy_acpi_init() fails
>>>>> * add sysfs attribute files for user space query.
>>>>> * add leds micmute driver to privacy acpi
>>>>> * add more design info the commit info
>>>>> ---
>>>>> ---
>>>>>  .../testing/sysfs-platform-dell-privacy-wmi   |  55 +++
>>>>>  drivers/platform/x86/dell/Kconfig             |  14 +
>>>>>  drivers/platform/x86/dell/Makefile            |   1 +
>>>>>  drivers/platform/x86/dell/dell-laptop.c       |  13 +-
>>>>>  drivers/platform/x86/dell/dell-privacy-wmi.c  | 394
>>>>> ++++++++++++++++++  drivers/platform/x86/dell/dell-privacy-wmi.h  |  25
>> ++
>>>>>  drivers/platform/x86/dell/dell-wmi.c          |   9 +-
>>>>>  7 files changed, 507 insertions(+), 4 deletions(-)  create mode
>>>>> 100644 Documentation/ABI/testing/sysfs-platform-dell-privacy-wmi
>>>>>  create mode 100644 drivers/platform/x86/dell/dell-privacy-wmi.c
>>>>>  create mode 100644 drivers/platform/x86/dell/dell-privacy-wmi.h
>>>>>
>>>>> diff --git
>>>>> a/Documentation/ABI/testing/sysfs-platform-dell-privacy-wmi
>>>>> b/Documentation/ABI/testing/sysfs-platform-dell-privacy-wmi
>>>>> new file mode 100644
>>>>> index 000000000000..7f9e18705861
>>>>> --- /dev/null
>>>>> +++ b/Documentation/ABI/testing/sysfs-platform-dell-privacy-wmi
>>>>> @@ -0,0 +1,55 @@
>>>>> +What:		/sys/bus/wmi/devices/6932965F-1671-4CEB-B988-
>> D3AB0A901919/dell_privacy_supported_type
>>>>> +Date:		Apr 2021
>>>>> +KernelVersion:	5.13
>>>>> +Contact:	"perry.yuan@dell.com>"
>>>>> +Description:
>>>>> +		Display which dell hardware level privacy devices are
>> supported
>>>>> +		“Dell Privacy” is a set of HW, FW, and SW features to enhance
>>>>> +		Dell’s commitment to platform privacy for MIC, Camera, and
>>>>> +		ePrivacy screens.
>>>>> +		The supported hardware privacy devices are:
>>>>> +Attributes:
>>>>> +		Microphone Mute:
>>>>> +				Identifies the local microphone can be muted
>> by hardware, no applications
>>>>> +				is available to capture system mic sound
>>>>> +
>>>>> +		Camera Shutter:
>>>>> +				Identifies camera shutter controlled by
>> hardware, which is a micromechanical
>>>>> +				shutter assembly that is built onto the camera
>> module to block capturing images
>>>>> +				from outside the laptop
>>>>> +
>>>>> +		supported:
>>>>> +				The privacy device is supported by this system
>>>>> +
>>>>> +		unsupported:
>>>>> +				The privacy device is not supported on this
>> system
>>>>> +
>>>>> +		For example to check which privacy devices are supported:
>>>>> +
>>>>> +		# cat /sys/bus/wmi/drivers/dell-privacy/6932965F-1671-
>> 4CEB-B988-D3AB0A901919/dell_privacy_supported_type
>>>>> +		[Microphone Mute] [supported]
>>>>> +		[Camera Shutter] [supported]
>>>>> +		[ePrivacy Screen] [unsupported]
>>>>> +
>>>>> +What:		/sys/bus/wmi/devices/6932965F-1671-4CEB-B988-
>> D3AB0A901919/dell_privacy_current_state
>>>>> +Date:		Apr 2021
>>>>> +KernelVersion:	5.13
>>>>> +Contact:	"perry.yuan@dell.com>"
>>>>> +Description:
>>>>> +		Allow user space to check current dell privacy device state.
>>>>> +		Describes the Device State class exposed by BIOS which can
>> be
>>>>> +		consumed by various applications interested in knowing the
>> Privacy
>>>>> +		feature capabilities
>>>>> +Attributes:
>>>>> +		muted:
>>>>> +			Identifies the privacy device is turned off and cannot
>> send
>>>>> +stream to OS applications
>>>>> +
>>>>> +		unmuted:
>>>>> +			Identifies the privacy device is turned on ,audio or
>> camera driver can get
>>>>> +			stream from mic and camera module to OS
>> applications
>>>>> +
>>>>> +		For example to check all supported current privacy device
>> states:
>>>>> +
>>>>> +		# cat /sys/bus/wmi/drivers/dell-privacy/6932965F-1671-
>> 4CEB-B988-D3AB0A901919/dell_privacy_current_state
>>>>> +		[Microphone] [unmuted]
>>>>> +		[Camera Shutter] [unmuted]
>>>>> diff --git a/drivers/platform/x86/dell/Kconfig
>>>>> b/drivers/platform/x86/dell/Kconfig
>>>>> index e0a55337f51a..be570ccbbce0 100644
>>>>> --- a/drivers/platform/x86/dell/Kconfig
>>>>> +++ b/drivers/platform/x86/dell/Kconfig
>>>>> @@ -204,4 +204,18 @@ config DELL_WMI_SYSMAN
>>>>>  	  To compile this driver as a module, choose M here: the module will
>>>>>  	  be called dell-wmi-sysman.
>>>>>
>>>>> +config DELL_PRIVACY
>>>>> +	tristate "Dell Hardware Privacy Support"
>>>>> +	depends on ACPI
>>>>> +	depends on ACPI_WMI
>>>>> +	depends on INPUT
>>>>> +	depends on DELL_LAPTOP
>>>>> +	depends on LEDS_TRIGGER_AUDIO
>>>>> +	depends on DELL_WMI
>>>>> +	help
>>>>> +	  This driver provides integration with the "Dell Hardware Privacy"
>> feature
>>>>> +	  of Dell laptops.
>>>>> +
>>>>> +	  To compile this driver as a module, choose M here: the module will
>>>>> +	  be called dell_privacy.
>>>>>  endif # X86_PLATFORM_DRIVERS_DELL
>>>>> diff --git a/drivers/platform/x86/dell/Makefile
>>>>> b/drivers/platform/x86/dell/Makefile
>>>>> index d720a3e42ae3..7da0c33dfcca 100644
>>>>> --- a/drivers/platform/x86/dell/Makefile
>>>>> +++ b/drivers/platform/x86/dell/Makefile
>>>>> @@ -19,3 +19,4 @@ obj-$(CONFIG_DELL_WMI_AIO)		+=
>> dell-wmi-aio.o
>>>>>  obj-$(CONFIG_DELL_WMI_DESCRIPTOR)	+= dell-wmi-descriptor.o
>>>>>  obj-$(CONFIG_DELL_WMI_LED)		+= dell-wmi-led.o
>>>>>  obj-$(CONFIG_DELL_WMI_SYSMAN)		+= dell-wmi-sysman/
>>>>> +obj-$(CONFIG_DELL_PRIVACY)              += dell-privacy-wmi.o
>>>>> diff --git a/drivers/platform/x86/dell/dell-laptop.c
>>>>> b/drivers/platform/x86/dell/dell-laptop.c
>>>>> index 70edc5bb3a14..529547fb0cb1 100644
>>>>> --- a/drivers/platform/x86/dell/dell-laptop.c
>>>>> +++ b/drivers/platform/x86/dell/dell-laptop.c
>>>>> @@ -31,6 +31,8 @@
>>>>>  #include "dell-rbtn.h"
>>>>>  #include "dell-smbios.h"
>>>>>
>>>>> +#include "dell-privacy-wmi.h"
>>>>> +
>>>>>  struct quirk_entry {
>>>>>  	bool touchpad_led;
>>>>>  	bool kbd_led_not_present;
>>>>> @@ -90,6 +92,7 @@ static struct rfkill *wifi_rfkill;  static struct
>>>>> rfkill *bluetooth_rfkill;  static struct rfkill *wwan_rfkill;
>>>>> static bool force_rfkill;
>>>>> +static bool micmute_led_registered;
>>>>>
>>>>>  module_param(force_rfkill, bool, 0444);
>>>>> MODULE_PARM_DESC(force_rfkill, "enable rfkill on non whitelisted
>>>>> models"); @@ -2205,11 +2208,13 @@ static int __init dell_init(void)
>>>>>  	dell_laptop_register_notifier(&dell_laptop_notifier);
>>>>>
>>>>>  	if (dell_smbios_find_token(GLOBAL_MIC_MUTE_DISABLE) &&
>>>>> -	    dell_smbios_find_token(GLOBAL_MIC_MUTE_ENABLE)) {
>>>>> +	    dell_smbios_find_token(GLOBAL_MIC_MUTE_ENABLE) &&
>>>>> +	    !dell_privacy_present()) {
>>>>>  		micmute_led_cdev.brightness =
>> ledtrig_audio_get(LED_AUDIO_MICMUTE);
>>>>>  		ret = led_classdev_register(&platform_device->dev,
>> &micmute_led_cdev);
>>>>>  		if (ret < 0)
>>>>>  			goto fail_led;
>>>>> +		micmute_led_registered = true;
>>>>>  	}
>>>>>
>>>>>  	if (acpi_video_get_backlight_type() != acpi_backlight_vendor) @@
>>>>> -2257,7 +2262,8 @@ static int __init dell_init(void)
>>>>>  fail_get_brightness:
>>>>>  	backlight_device_unregister(dell_backlight_device);
>>>>>  fail_backlight:
>>>>> -	led_classdev_unregister(&micmute_led_cdev);
>>>>> +	if (micmute_led_registered)
>>>>> +		led_classdev_unregister(&micmute_led_cdev);
>>>>>  fail_led:
>>>>>  	dell_cleanup_rfkill();
>>>>>  fail_rfkill:
>>>>> @@ -2278,7 +2284,8 @@ static void __exit dell_exit(void)
>>>>>  		touchpad_led_exit();
>>>>>  	kbd_led_exit();
>>>>>  	backlight_device_unregister(dell_backlight_device);
>>>>> -	led_classdev_unregister(&micmute_led_cdev);
>>>>> +	if (micmute_led_registered)
>>>>> +		led_classdev_unregister(&micmute_led_cdev);
>>>>>  	dell_cleanup_rfkill();
>>>>>  	if (platform_device) {
>>>>>  		platform_device_unregister(platform_device);
>>>>> diff --git a/drivers/platform/x86/dell/dell-privacy-wmi.c
>>>>> b/drivers/platform/x86/dell/dell-privacy-wmi.c
>>>>> new file mode 100644
>>>>> index 000000000000..a32d0fbd99da
>>>>> --- /dev/null
>>>>> +++ b/drivers/platform/x86/dell/dell-privacy-wmi.c
>>>>> @@ -0,0 +1,394 @@
>>>>> +// SPDX-License-Identifier: GPL-2.0-only
>>>>> +/*
>>>>> + * Dell privacy notification driver
>>>>> + *
>>>>> + * Copyright (C) 2021 Dell Inc. All Rights Reserved.
>>>>> + */
>>>>> +
>>>>> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>>>>> +
>>>>> +#include <linux/acpi.h>
>>>>> +#include <linux/bitops.h>
>>>>> +#include <linux/input.h>
>>>>> +#include <linux/input/sparse-keymap.h> #include <linux/list.h>
>>>>> +#include <linux/leds.h> #include <linux/module.h> #include
>>>>> +<linux/wmi.h>
>>>>> +
>>>>> +#include "dell-privacy-wmi.h"
>>>>> +
>>>>> +#define DELL_PRIVACY_GUID "6932965F-1671-4CEB-B988-
>> D3AB0A901919"
>>>>> +#define MICROPHONE_STATUS		BIT(0)
>>>>> +#define CAMERA_STATUS		        BIT(1)
>>>>> +#define DELL_PRIVACY_AUDIO_EVENT  0x1 #define
>>>>> +DELL_PRIVACY_CAMERA_EVENT 0x2
>>>>> +#define led_to_priv(c)       container_of(c, struct privacy_wmi_data, cdev)
>>>>> +
>>>>> +/*
>>>>> + * The wmi_list is used to store the privacy_priv struct with mutex
>>>>> +protecting  */ static LIST_HEAD(wmi_list); static
>>>>> +DEFINE_MUTEX(list_mutex);
>>>>> +
>>>>> +struct privacy_wmi_data {
>>>>> +	struct input_dev *input_dev;
>>>>> +	struct wmi_device *wdev;
>>>>> +	struct list_head list;
>>>>> +	struct led_classdev cdev;
>>>>> +	u32 features_present;
>>>>> +	u32 last_status;
>>>>> +};
>>>>> +
>>>>> +/* DELL Privacy Type */
>>>>> +enum dell_hardware_privacy_type {
>>>>> +	DELL_PRIVACY_TYPE_AUDIO = 0,
>>>>> +	DELL_PRIVACY_TYPE_CAMERA,
>>>>> +	DELL_PRIVACY_TYPE_SCREEN,
>>>>> +	DELL_PRIVACY_TYPE_MAX,
>>>>> +};
>>>>> +
>>>>> +static const char * const privacy_types[DELL_PRIVACY_TYPE_MAX] = {
>>>>> +	[DELL_PRIVACY_TYPE_AUDIO] = "Microphone",
>>>>> +	[DELL_PRIVACY_TYPE_CAMERA] = "Camera Shutter",
>>>>> +	[DELL_PRIVACY_TYPE_SCREEN] = "ePrivacy Screen", };
>>>>> +
>>>>> +/*
>>>>> + * Keymap for WMI privacy events of type 0x0012  */ static const
>>>>> +struct key_entry dell_wmi_keymap_type_0012[] = {
>>>>> +	/* privacy mic mute */
>>>>> +	{ KE_KEY, 0x0001, { KEY_MICMUTE } },
>>>>> +	/* privacy camera mute */
>>>>> +	{ KE_SW,  0x0002, { SW_CAMERA_LENS_COVER } },
>>>>> +	{ KE_END, 0},
>>>>> +};
>>>>> +
>>>>> +/*
>>>>> + * global privacy state for other modules to query if the privacy
>>>>> +driver loaded successfully
>>>>> + * or no privacy WMI device was detected at initial probe phase  */
>>>>> +bool dell_privacy_present(void) {
>>>>> +	struct privacy_wmi_data *priv;
>>>>> +
>>>>> +	mutex_lock(&list_mutex);
>>>>> +	priv = list_first_entry_or_null(&wmi_list,
>>>>> +			struct privacy_wmi_data,
>>>>> +			list);
>>>>> +	mutex_unlock(&list_mutex);
>>>>> +
>>>>> +	return priv && (priv->features_present &
>>>>> +BIT(DELL_PRIVACY_TYPE_AUDIO)); }
>>>>> +EXPORT_SYMBOL_GPL(dell_privacy_present);
>>>>> +
>>>>> +/*
>>>>> + * The flow of privacy event:
>>>>> + * 1) User presses key. HW does stuff with this key (timeout is
>>>>> +started)
>>>>> + * 2) WMI event is emitted from BIOS
>>>>> + * 3) WMI event is received by dell-privacy
>>>>> + * 4) KEY_MICMUTE emitted from dell-privacy
>>>>> + * 5) Userland picks up key and modifies kcontrol for SW mute
>>>>> + * 6) Codec kernel driver catches and calls ledtrig_audio_set defined by
>>>>> + *    dell-privacy-acpi driver. Codec driver will call like this to switch
>> micmute led state.
>>>>> + *    ledtrig_audio_set(LED_AUDIO_MICMUTE, micmute_led ?
>> LED_ON :LED_OFF);
>>>>> + * 7) If "LED" is set to on dell-privacy notifies EC,and timeout is cancelled,
>>>>> + *	HW mic mute activated.
>>>>> + */
>>>>> +bool dell_privacy_process_event(int type, int code, int status) {
>>>>> +	struct privacy_wmi_data *priv;
>>>>> +	const struct key_entry *key;
>>>>> +	bool ret = false;
>>>>> +
>>>>> +	mutex_lock(&list_mutex);
>>>>> +	priv = list_first_entry_or_null(&wmi_list,
>>>>> +			struct privacy_wmi_data,
>>>>> +			list);
>>>>> +	if (!priv)
>>>>> +		goto error;
>>>>> +
>>>>> +	key = sparse_keymap_entry_from_scancode(priv->input_dev, (type <<
>> 16) | code);
>>>>> +	if (!key) {
>>>>> +		dev_warn(&priv->wdev->dev, "Unknown key with type
>> 0x%04x and code 0x%04x pressed\n",
>>>>> +			type, code);
>>>>> +		goto error;
>>>>> +	}
>>>>> +	dev_dbg(&priv->wdev->dev, "Key with type 0x%04x and code 0x%04x
>>>>> +pressed\n", type, code);
>>>>> +
>>>>> +	switch (code) {
>>>>> +	case DELL_PRIVACY_AUDIO_EVENT: /* Mic mute */
>>>>> +	case DELL_PRIVACY_CAMERA_EVENT: /* Camera mute */
>>>>> +		priv->last_status = status;
>>>>> +		sparse_keymap_report_entry(priv->input_dev, key, 1, true);
>>>>> +		ret = true;
>>>>> +		break;
>>>>> +	default:
>>>>> +		dev_dbg(&priv->wdev->dev, "unknown event type 0x%04x
>> 0x%04x\n", type, code);
>>>>> +	}
>>>>> +
>>>>> +error:
>>>>> +	mutex_unlock(&list_mutex);
>>>>> +	return ret;
>>>>> +}
>>>>> +EXPORT_SYMBOL_GPL(dell_privacy_process_event);
>>>>> +
>>>>> +static ssize_t dell_privacy_supported_type_show(struct device *dev,
>>>>> +					struct device_attribute *attr,
>>>>> +					char *buf)
>>>>> +{
>>>>> +	struct privacy_wmi_data *priv = dev_get_drvdata(dev);
>>>>> +	enum dell_hardware_privacy_type type;
>>>>> +	u32 privacy_list;
>>>>> +	int len = 0;
>>>>> +
>>>>> +	privacy_list = priv->features_present;
>>>>> +	for (type = DELL_PRIVACY_TYPE_AUDIO; type <
>> DELL_PRIVACY_TYPE_MAX; type++) {
>>>>> +		if (privacy_list & BIT(type))
>>>>> +			len += sysfs_emit_at(buf, len, "[%s] [supported]\n",
>> privacy_types[type]);
>>>>> +		else
>>>>> +			len += sysfs_emit_at(buf, len, "[%s] [unsupported]\n",
>> privacy_types[type]);
>>>>> +	}
>>>>> +
>>>>> +	return len;
>>>>> +}
>>>>> +
>>>>> +static ssize_t dell_privacy_current_state_show(struct device *dev,
>>>>> +					struct device_attribute *attr,
>>>>> +					char *buf)
>>>>> +{
>>>>> +	struct privacy_wmi_data *priv = dev_get_drvdata(dev);
>>>>> +	u32 privacy_supported = priv->features_present;
>>>>> +	enum dell_hardware_privacy_type type;
>>>>> +	u32 privacy_state = priv->last_status;
>>>>> +	int len = 0;
>>>>> +
>>>>> +	for (type = DELL_PRIVACY_TYPE_AUDIO; type <
>> DELL_PRIVACY_TYPE_MAX; type++) {
>>>>> +		if (privacy_supported & BIT(type)) {
>>>>> +			if (privacy_state & BIT(type))
>>>>> +				len += sysfs_emit_at(buf, len, "[%s]
>> [unmuted]\n", privacy_types[type]);
>>>>> +			else
>>>>> +				len += sysfs_emit_at(buf, len, "[%s]
>> [muted]\n", privacy_types[type]);
>>>>> +		}
>>>>> +	}
>>>>> +
>>>>> +	return len;
>>>>> +}
>>>>> +
>>>>> +static DEVICE_ATTR_RO(dell_privacy_supported_type);
>>>>> +static DEVICE_ATTR_RO(dell_privacy_current_state);
>>>>> +
>>>>> +static struct attribute *privacy_attributes[] = {
>>>>> +	&dev_attr_dell_privacy_supported_type.attr,
>>>>> +	&dev_attr_dell_privacy_current_state.attr,
>>>>> +	NULL,
>>>>> +};
>>>>> +
>>>>> +static const struct attribute_group privacy_attribute_group = {
>>>>> +	.attrs = privacy_attributes
>>>>> +};
>>>>> +
>>>>> +/*
>>>>> + * Describes the Device State class exposed by BIOS which can be
>>>>> +consumed by
>>>>> + * various applications interested in knowing the Privacy feature
>> capabilities.
>>>>> + * class DeviceState
>>>>> + * {
>>>>> + *  [key, read] string InstanceName;
>>>>> + *  [read] boolean ReadOnly;
>>>>> + *
>>>>> + *  [WmiDataId(1), read] uint32 DevicesSupported;
>>>>> + *   0 - None; 0x1 - Microphone; 0x2 - Camera; 0x4 - ePrivacy  Screen
>>>>> + *
>>>>> + *  [WmiDataId(2), read] uint32 CurrentState;
>>>>> + *   0 - Off; 1 - On; Bit0 - Microphone; Bit1 - Camera; Bit2 -
>> ePrivacyScreen
>>>>> + * };
>>>>> + */
>>>>> +static int get_current_status(struct wmi_device *wdev) {
>>>>> +	struct privacy_wmi_data *priv = dev_get_drvdata(&wdev->dev);
>>>>> +	union acpi_object *obj_present;
>>>>> +	u32 *buffer;
>>>>> +	int ret = 0;
>>>>> +
>>>>> +	if (!priv) {
>>>>> +		dev_err(&wdev->dev, "dell privacy priv is NULL\n");
>>>>> +		return -EINVAL;
>>>>> +	}
>>>>> +	/* check privacy support features and device states */
>>>>> +	obj_present = wmidev_block_query(wdev, 0);
>>>>> +	if (!obj_present) {
>>>>> +		dev_err(&wdev->dev, "failed to read Binary MOF\n");
>>>>> +		return -EIO;
>>>>> +	}
>>>>> +
>>>>> +	if (obj_present->type != ACPI_TYPE_BUFFER) {
>>>>> +		dev_err(&wdev->dev, "Binary MOF is not a buffer!\n");
>>>>> +		ret = -EIO;
>>>>> +		goto obj_free;
>>>>> +	}
>>>>> +	/*  Although it's not technically a failure, this would lead to
>>>>> +	 *  unexpected behavior
>>>>> +	 */
>>>>> +	if (obj_present->buffer.length != 8) {
>>>>> +		dev_err(&wdev->dev, "Dell privacy buffer has unexpected
>> length (%d)!\n",
>>>>> +				obj_present->buffer.length);
>>>>> +		ret = -EINVAL;
>>>>> +		goto obj_free;
>>>>> +	}
>>>>> +	buffer = (u32 *)obj_present->buffer.pointer;
>>>>> +	priv->features_present = buffer[0];
>>>>> +	priv->last_status = buffer[1];
>>>>> +
>>>>> +obj_free:
>>>>> +	kfree(obj_present);
>>>>> +	return ret;
>>>>> +}
>>>>> +
>>>>> +static int dell_privacy_micmute_led_set(struct led_classdev *led_cdev,
>>>>> +					enum led_brightness brightness) {
>>>>> +	struct privacy_wmi_data *priv = led_to_priv(led_cdev);
>>>>> +	static char *acpi_method = (char *)"ECAK";
>>>>> +	acpi_status status;
>>>>> +	acpi_handle handle;
>>>>> +
>>>>> +	handle = ec_get_handle();
>>>>> +	if (!handle)
>>>>> +		return -EIO;
>>>>> +
>>>>> +	if (!acpi_has_method(handle, acpi_method))
>>>>> +		return -EIO;
>>>>> +
>>>>> +	status = acpi_evaluate_object(handle, acpi_method, NULL, NULL);
>>>>> +	if (ACPI_FAILURE(status)) {
>>>>> +		dev_err(&priv->wdev->dev, "Error setting privacy EC ack
>> value: %s\n",
>>>>> +				acpi_format_exception(status));
>>>>> +		return -EIO;
>>>>> +	}
>>>>> +
>>>>> +	return 0;
>>>>> +}
>>>>> +
>>>>> +/*
>>>>> + * Pressing the mute key activates a time delayed circuit to
>>>>> +physically cut
>>>>> + * off the mute. The LED is in the same circuit, so it reflects the
>>>>> +true
>>>>> + * state of the HW mute.  The reason for the EC "ack" is so that
>>>>> +software
>>>>> + * can first invoke a SW mute before the HW circuit is cut off.
>>>>> +Without SW
>>>>> + * cutting this off first does not affect the time delayed muting
>>>>> +or status
>>>>> + * of the LED but there is a possibility of a "popping" noise.
>>>>> + *
>>>>> + * If the EC receives the SW ack, the circuit will be activated
>>>>> +before the
>>>>> + * delay completed.
>>>>> + *
>>>>> + * Exposing as an LED device allows the codec drivers notification
>>>>> +path to
>>>>> + * EC ACK to work
>>>>> + */
>>>>> +static int dell_privacy_leds_setup(struct device *dev) {
>>>>> +	struct privacy_wmi_data *priv = dev_get_drvdata(dev);
>>>>> +
>>>>> +	priv->cdev.name = "dell-privacy::micmute";
>>>>> +	priv->cdev.max_brightness = 1;
>>>>> +	priv->cdev.brightness_set_blocking = dell_privacy_micmute_led_set;
>>>>> +	priv->cdev.default_trigger = "audio-micmute";
>>>>> +	priv->cdev.brightness = ledtrig_audio_get(LED_AUDIO_MICMUTE);
>>>>> +	return devm_led_classdev_register(dev, &priv->cdev); }
>>>>> +
>>>>> +static int dell_privacy_wmi_probe(struct wmi_device *wdev, const
>>>>> +void *context) {
>>>>> +	struct privacy_wmi_data *priv;
>>>>> +	struct key_entry *keymap;
>>>>> +	int ret, i;
>>>>> +
>>>>> +	ret = wmi_has_guid(DELL_PRIVACY_GUID);
>>>>> +	if (!ret)
>>>>> +		pr_debug("Unable to detect available Dell privacy
>> devices!\n");
>>>>> +
>>>>> +	priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
>>>>> +	if (!priv)
>>>>> +		return -ENOMEM;
>>>>> +
>>>>> +	dev_set_drvdata(&wdev->dev, priv);
>>>>> +	priv->wdev = wdev;
>>>>> +	/* create evdev passing interface */
>>>>> +	priv->input_dev = devm_input_allocate_device(&wdev->dev);
>>>>> +	if (!priv->input_dev)
>>>>> +		return -ENOMEM;
>>>>> +
>>>>> +	/* remap the wmi keymap event to new keymap */
>>>>> +	keymap = kcalloc(ARRAY_SIZE(dell_wmi_keymap_type_0012),
>>>>> +			sizeof(struct key_entry), GFP_KERNEL);
>>>>> +	if (!keymap)
>>>>> +		return -ENOMEM;
>>>>> +
>>>>> +	/* remap the keymap code with Dell privacy key type 0x12 as prefix
>>>>> +	 * KEY_MICMUTE scancode will be reported as 0x120001
>>>>> +	 */
>>>>> +	for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0012); i++) {
>>>>> +		keymap[i] = dell_wmi_keymap_type_0012[i];
>>>>> +		keymap[i].code |= (0x0012 << 16);
>>>>> +	}
>>>>> +	ret = sparse_keymap_setup(priv->input_dev, keymap, NULL);
>>>>> +	kfree(keymap);
>>>>> +	if (ret)
>>>>> +		return ret;
>>>>> +
>>>>> +	priv->input_dev->dev.parent = &wdev->dev;
>>>>> +	priv->input_dev->name = "Dell Privacy Driver";
>>>>> +	priv->input_dev->id.bustype = BUS_HOST;
>>>>> +
>>>>> +	ret = input_register_device(priv->input_dev);
>>>>> +	if (ret)
>>>>> +		return ret;
>>>>> +
>>>>> +	ret = get_current_status(priv->wdev);
>>>>> +	if (ret)
>>>>> +		return ret;
>>>>> +
>>>>> +	ret = devm_device_add_group(&wdev->dev,
>> &privacy_attribute_group);
>>>>> +	if (ret)
>>>>> +		return ret;
>>>>> +
>>>>> +	if (priv->features_present & BIT(DELL_PRIVACY_TYPE_AUDIO)) {
>>>>> +		ret = dell_privacy_leds_setup(&priv->wdev->dev);
>>>>> +		if (ret)
>>>>> +			return ret;
>>>>> +	}
>>>>> +	mutex_lock(&list_mutex);
>>>>> +	list_add_tail(&priv->list, &wmi_list);
>>>>> +	mutex_unlock(&list_mutex);
>>>>> +	return 0;
>>>>> +}
>>>>> +
>>>>> +static int dell_privacy_wmi_remove(struct wmi_device *wdev) {
>>>>> +	struct privacy_wmi_data *priv = dev_get_drvdata(&wdev->dev);
>>>>> +
>>>>> +	mutex_lock(&list_mutex);
>>>>> +	list_del(&priv->list);
>>>>> +	mutex_unlock(&list_mutex);
>>>>> +	return 0;
>>>>> +}
>>>>> +
>>>>> +static const struct wmi_device_id dell_wmi_privacy_wmi_id_table[] = {
>>>>> +	{ .guid_string = DELL_PRIVACY_GUID },
>>>>> +	{ },
>>>>> +};
>>>>> +
>>>>> +static struct wmi_driver dell_privacy_wmi_driver = {
>>>>> +	.driver = {
>>>>> +		.name = "dell-privacy",
>>>>> +	},
>>>>> +	.probe = dell_privacy_wmi_probe,
>>>>> +	.remove = dell_privacy_wmi_remove,
>>>>> +	.id_table = dell_wmi_privacy_wmi_id_table, };
>>>>> +
>>>>> +module_wmi_driver(dell_privacy_wmi_driver);
>>>>> +
>>>>> +MODULE_DEVICE_TABLE(wmi, dell_wmi_privacy_wmi_id_table);
>>>>> +MODULE_AUTHOR("Perry Yuan <perry_yuan@dell.com>");
>>>>> +MODULE_DESCRIPTION("Dell Privacy WMI Driver");
>>>>> +MODULE_LICENSE("GPL");
>>>>> diff --git a/drivers/platform/x86/dell/dell-privacy-wmi.h
>>>>> b/drivers/platform/x86/dell/dell-privacy-wmi.h
>>>>> new file mode 100644
>>>>> index 000000000000..54004eed7213
>>>>> --- /dev/null
>>>>> +++ b/drivers/platform/x86/dell/dell-privacy-wmi.h
>>>>> @@ -0,0 +1,25 @@
>>>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>>>> +/*
>>>>> + * Dell privacy notification driver
>>>>> + *
>>>>> + * Copyright (C) 2021 Dell Inc. All Rights Reserved.
>>>>> + */
>>>>> +
>>>>> +#ifndef _DELL_PRIVACY_WMI_H_
>>>>> +#define _DELL_PRIVACY_WMI_H_
>>>>> +
>>>>> +#if IS_ENABLED(CONFIG_DELL_PRIVACY) bool
>>>>> +dell_privacy_present(void); bool dell_privacy_process_event(int
>>>>> +type, int code, int status); #else /* CONFIG_DELL_PRIVACY */ static
>>>>> +inline bool dell_privacy_present(void) {
>>>>> +	return -ENODEV;
>>>>> +}
>>>>> +
>>>>> +static inline bool dell_privacy_process_event(int type, int code,
>>>>> +int status) {
>>>>> +	return false;
>>>>> +}
>>>>> +#endif /* CONFIG_DELL_PRIVACY */
>>>>> +#endif
>>>>> diff --git a/drivers/platform/x86/dell/dell-wmi.c
>>>>> b/drivers/platform/x86/dell/dell-wmi.c
>>>>> index bbdb3e860892..20367a580fa0 100644
>>>>> --- a/drivers/platform/x86/dell/dell-wmi.c
>>>>> +++ b/drivers/platform/x86/dell/dell-wmi.c
>>>>> @@ -27,6 +27,7 @@
>>>>>  #include <acpi/video.h>
>>>>>  #include "dell-smbios.h"
>>>>>  #include "dell-wmi-descriptor.h"
>>>>> +#include "dell-privacy-wmi.h"
>>>>>
>>>>>  MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
>>>>> MODULE_AUTHOR("Pali Rohár <pali@kernel.org>"); @@ -427,7 +428,6
>> @@
>>>>> static void dell_wmi_notify(struct wmi_device *wdev,
>>>>>
>>>>>  		switch (buffer_entry[1]) {
>>>>>  		case 0x0000: /* One key pressed or event occurred */
>>>>> -		case 0x0012: /* Event with extended data occurred */
>>>>>  			if (len > 2)
>>>>>  				dell_wmi_process_key(wdev, buffer_entry[1],
>>>>>  						     buffer_entry[2]);
>>>>> @@ -439,6 +439,13 @@ static void dell_wmi_notify(struct wmi_device
>> *wdev,
>>>>>  				dell_wmi_process_key(wdev, buffer_entry[1],
>>>>>  						     buffer_entry[i]);
>>>>>  			break;
>>>>> +		case 0x0012:
>>>>> +			if ((len > 4) &&
>> dell_privacy_process_event(buffer_entry[1], buffer_entry[3],
>>>>> +
>> buffer_entry[4]))
>>>>> +				/* dell_privacy_process_event has handled
>> the event */;
>>>>> +			else if (len > 2)
>>>>> +				dell_wmi_process_key(wdev, buffer_entry[1],
>> buffer_entry[2]);
>>>>> +			break;
>>>>>  		default: /* Unknown event */
>>>>>  			pr_info("Unknown WMI event type 0x%x\n",
>>>>>  				(int)buffer_entry[1]);
>>>>>
>