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

["Yuan, Perry" <Perry.Yuan@dell.com>]

Hi Hans

> -----Original Message-----
> From: Hans de Goede <hdegoede@redhat.com>
> Sent: 2021年5月27日 17:23
> 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,
> 
> 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

Great. I saw the commit merged.
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/commit/?h=for-next

Thanks so much for your lots of efforts on this review and feedback.

Perry 
> 
> 
> 
> 
> >>>>> 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]);
> >>>>>
> >