Date:   Tue, 18 May 2021 15:02:54 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     Perry Yuan <Perry.Yuan@...l.com>, pobrn@...tonmail.com,
        pierre-louis.bossart@...ux.intel.com, oder_chiou@...ltek.com,
        perex@...ex.cz, tiwai@...e.com, mgross@...ux.intel.com
Cc:     lgirdwood@...il.com, broonie@...nel.org,
        alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
        platform-driver-x86@...r.kernel.org, mario.limonciello@...look.com,
        Dell.Client.Kernel@...l.com
Subject: Re: [PATCH v8 1/2] platform/x86: dell-privacy: Add support for Dell
 hardware privacy

Hi Perry,

On 5/6/21 1:56 PM, Perry Yuan wrote:
> From: Perry Yuan <perry_yuan@...l.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@...l.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.

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@...l.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@...l.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@...l.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@...hat.com>");
>  MODULE_AUTHOR("Pali Rohár <pali@...nel.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]);
> 

View attachment "0001-platform-x86-dell-wmi-Rename-dell-wmi.c-to-dell-wmi-.patch" of type "text/x-patch" (2058 bytes)

View attachment "0002-platform-x86-dell-privacy-Add-support-for-Dell-hardw.patch" of type "text/x-patch" (22087 bytes)

View attachment "0003-FIXUP-platform-x86-dell-privacy-Add-support-for-Dell.patch" of type "text/x-patch" (7559 bytes)

View attachment "0004-FIXUP-platform-x86-dell-privacy-Add-support-for-Dell.patch" of type "text/x-patch" (5682 bytes)

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