diff mbox series

[v3,1/3] platform/x86: dell-privacy: Add support for Dell hardware privacy

Message ID 20210112171723.19484-1-Perry_Yuan@Dell.com (mailing list archive)
State New, archived
Headers show
Series Dell hardware privacy implementation for dell laptop | expand

Commit Message

Yuan, Perry Jan. 12, 2021, 5:17 p.m. UTC
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
enabled, 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 emmit
SW_CAMERA_LENS_COVER event while the camera lens shutter will be
changed by EC & hw(hadware) control

*The flow is like this:
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, 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.

Signed-off-by: Perry Yuan <perry_yuan@dell.com>
---
v3 -> v4:
* changed as Barnabás`s review comments
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
---
---
 drivers/platform/x86/Kconfig             |  17 ++
 drivers/platform/x86/Makefile            |   4 +-
 drivers/platform/x86/dell-laptop.c       |  25 +-
 drivers/platform/x86/dell-privacy-acpi.c | 167 ++++++++++++
 drivers/platform/x86/dell-privacy-wmi.c  | 320 +++++++++++++++++++++++
 drivers/platform/x86/dell-privacy-wmi.h  |  33 +++
 drivers/platform/x86/dell-wmi.c          |  37 ++-
 7 files changed, 587 insertions(+), 16 deletions(-)
 create mode 100644 drivers/platform/x86/dell-privacy-acpi.c
 create mode 100644 drivers/platform/x86/dell-privacy-wmi.c
 create mode 100644 drivers/platform/x86/dell-privacy-wmi.h

Comments

Randy Dunlap Jan. 12, 2021, 5:39 p.m. UTC | #1
On 1/12/21 9:17 AM, Perry Yuan wrote:
> +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
> +	select DELL_WMI
> +	help
> +	This driver provides support for the "Dell Hardware Privacy" feature
> +	of Dell laptops.
> +	Support for a micmute and camera mute privacy will be provided as
> +	hardware button Ctrl+F4 and Ctrl+F9 hotkey

	End above with a period '.' please.

> +
> +	To compile this driver as a module, choose M here: the module will
> +	be called dell_privacy.

Please follow coding-style for Kconfig files:

from Documentation/process/coding-style.rst, section 10):

For all of the Kconfig* configuration files throughout the source tree,
the indentation is somewhat different.  Lines under a ``config`` definition
are indented with one tab, while help text is indented an additional two
spaces.


thanks.
Pierre-Louis Bossart Jan. 12, 2021, 7 p.m. UTC | #2
On 1/12/21 11:17 AM, 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
> enabled, 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 emmit
> SW_CAMERA_LENS_COVER event while the camera lens shutter will be
> changed by EC & hw(hadware) control

It wouldn't hurt to use capital letters and punctuation, it helps with 
readility..

[...]

> diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
> index 70edc5bb3a14..2fea1f34fcf9 100644
> --- a/drivers/platform/x86/dell-laptop.c
> +++ b/drivers/platform/x86/dell-laptop.c
> @@ -30,6 +30,7 @@
>   #include <acpi/video.h>
>   #include "dell-rbtn.h"
>   #include "dell-smbios.h"
> +#include "dell-privacy-wmi.h"
>   
>   struct quirk_entry {
>   	bool touchpad_led;
> @@ -90,6 +91,7 @@ static struct rfkill *wifi_rfkill;
>   static struct rfkill *bluetooth_rfkill;
>   static struct rfkill *wwan_rfkill;
>   static bool force_rfkill;
> +static bool privacy_valid;

why is this variable needed? Was the intent to have a kernel parameter here?

>   module_param(force_rfkill, bool, 0444);
>   MODULE_PARM_DESC(force_rfkill, "enable rfkill on non whitelisted models");
> @@ -2205,11 +2207,18 @@ 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)) {
> -		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;
> +			dell_smbios_find_token(GLOBAL_MIC_MUTE_ENABLE)) {
> +#if IS_ENABLED(CONFIG_DELL_PRIVACY)
> +		ret = dell_privacy_valid();
> +		if (!ret)
> +			privacy_valid = true;
> +#endif
> +		if (!privacy_valid) {

if it was intended to be used as a kernel parameter it's not done the 
right way: the value set by the user would be ignored...

> +			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;
> +		}
>   	}
>   
>   	if (acpi_video_get_backlight_type() != acpi_backlight_vendor)
> @@ -2257,7 +2266,8 @@ static int __init dell_init(void)
>   fail_get_brightness:
>   	backlight_device_unregister(dell_backlight_device);
>   fail_backlight:
> -	led_classdev_unregister(&micmute_led_cdev);
> +	if (!privacy_valid)
> +		led_classdev_unregister(&micmute_led_cdev);
>   fail_led:
>   	dell_cleanup_rfkill();
>   fail_rfkill:
> @@ -2278,7 +2288,8 @@ 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 (!privacy_valid)
> +		led_classdev_unregister(&micmute_led_cdev);
>   	dell_cleanup_rfkill();
>   	if (platform_device) {
>   		platform_device_unregister(platform_device);
> diff --git a/drivers/platform/x86/dell-privacy-acpi.c b/drivers/platform/x86/dell-privacy-acpi.c
> new file mode 100644
> index 000000000000..df6a86e1345c
> --- /dev/null
> +++ b/drivers/platform/x86/dell-privacy-acpi.c
> @@ -0,0 +1,167 @@
> +// 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/bits.h>
> +#include <linux/device.h>
> +#include <linux/fs.h>
> +#include <linux/kernel.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/platform_device.h>
> +#include <linux/string.h>
> +#include <linux/sysfs.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +#include <linux/wmi.h>
> +
> +#include "dell-privacy-wmi.h"
> +
> +#define PRIVACY_PLATFORM_NAME	"dell-privacy-acpi"
> +#define DELL_PRIVACY_GUID	"6932965F-1671-4CEB-B988-D3AB0A901919"
> +
> +struct privacy_acpi_priv {
> +	struct device *dev;
> +	struct platform_device *platform_device;
> +	struct led_classdev cdev;
> +};
> +static struct privacy_acpi_priv *privacy_acpi;
> +
> +static int dell_privacy_micmute_led_set(struct led_classdev *led_cdev,
> +		enum led_brightness brightness)
> +{
> +	struct privacy_acpi_priv *priv = privacy_acpi;
> +	acpi_status status;
> +	acpi_handle handle;
> +	char *acpi_method;
> +
> +	handle = ec_get_handle();
> +	if (!handle)
> +		return -EIO;
> +	acpi_method = "ECAK";
> +	status = acpi_evaluate_object(handle, acpi_method, NULL, NULL);
> +	if (ACPI_FAILURE(status)) {
> +		dev_err(priv->dev, "Error setting privacy EC ack value: %s\n",
> +				acpi_format_exception(status));
> +		return -EIO;
> +	}
> +	return 0;
> +}
> +
> +static int dell_privacy_acpi_remove(struct platform_device *pdev)
> +{
> +	struct privacy_acpi_priv *priv = dev_get_drvdata(privacy_acpi->dev);
> +
> +	led_classdev_unregister(&priv->cdev);
> +
> +	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_acpi_priv *priv = dev_get_drvdata(dev);
> +	int ret = 0;
> +
> +	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);
> +	ret = devm_led_classdev_register(dev, &priv->cdev);
> +	if (ret < 0)
> +		return ret;
> +	return 0;
> +}
> +
> +static int dell_privacy_acpi_probe(struct platform_device *pdev)
> +{
> +	platform_set_drvdata(pdev, privacy_acpi);
> +	privacy_acpi->dev = &pdev->dev;
> +	privacy_acpi->platform_device = pdev;
> +	return 0;
> +}
> +
> +static const struct acpi_device_id privacy_acpi_device_ids[] = {
> +	{"PNP0C09", 0},
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(acpi, privacy_acpi_device_ids);
> +
> +static struct platform_driver dell_privacy_platform_drv = {
> +	.driver = {
> +		.name = PRIVACY_PLATFORM_NAME,
> +		.acpi_match_table = ACPI_PTR(privacy_acpi_device_ids),
> +	},

no .probe?

> +	.remove = dell_privacy_acpi_remove,
> +};
> +
> +int __init dell_privacy_acpi_init(void)
> +{
> +	int err;
> +	struct platform_device *pdev;
> +	int privacy_capable = wmi_has_guid(DELL_PRIVACY_GUID);
> +
> +	if (!wmi_has_guid(DELL_PRIVACY_GUID))
> +		return -ENODEV;
> +
> +	privacy_acpi = kzalloc(sizeof(*privacy_acpi), GFP_KERNEL);
> +	if (!privacy_acpi)
> +		return -ENOMEM;
> +
> +	pdev = platform_device_register_simple(
> +			PRIVACY_PLATFORM_NAME, PLATFORM_DEVID_NONE, NULL, 0);
> +	if (IS_ERR(pdev)) {
> +		err = PTR_ERR(pdev);
> +		goto pdev_err;
> +	}
> +	err = platform_driver_probe(&dell_privacy_platform_drv,
> +			dell_privacy_acpi_probe);
> +	if (err)
> +		goto pdrv_err;

why is the probe done here? Put differently, what prevents you from 
using a 'normal' platform driver, and do the leds_setup in the .probe()?

> +
> +	err = dell_privacy_leds_setup(&pdev->dev);
> +	if (err < 0)
> +		goto pdrv_err;
> +
> +	return 0;
> +
> +pdrv_err:
> +	platform_device_unregister(pdev);
> +pdev_err:
> +	kfree(privacy_acpi);
> +	return err;
> +}
> +
> +void __exit dell_privacy_acpi_exit(void)
> +{
> +	struct platform_device *pdev = to_platform_device(privacy_acpi->dev);
> +
> +	platform_device_unregister(pdev);
> +	platform_driver_unregister(&dell_privacy_platform_drv);
> +	kfree(privacy_acpi);
> +}
> +
> +MODULE_AUTHOR("Perry Yuan <perry_yuan@dell.com>");
> +MODULE_DESCRIPTION("DELL Privacy ACPI Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/platform/x86/dell-privacy-wmi.c b/drivers/platform/x86/dell-privacy-wmi.c
> new file mode 100644
> index 000000000000..432a3f4ed226
> --- /dev/null
> +++ b/drivers/platform/x86/dell-privacy-wmi.c
> @@ -0,0 +1,320 @@
> +// 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/input.h>
> +#include <linux/input/sparse-keymap.h>
> +#include <linux/list.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 PRIVACY_SCREEN_STATUS		BIT(2)
> +
> +static int privacy_valid = -EPROBE_DEFER;

this is set to -ENODEV on remove. that looks odd to me.

> +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;
> +	u32 features_present;
> +	u32 last_status;
> +};
> +
> +/*
> + * 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},
> +};
> +
> +int dell_privacy_valid(void)
> +{
> +	int ret;
> +
> +	ret = wmi_has_guid(DELL_PRIVACY_GUID);
> +	if (!ret)
> +		return -ENODEV;
> +	ret = privacy_valid;
> +	return ret;

return privacy_valid?

> +}
> +EXPORT_SYMBOL_GPL(dell_privacy_valid);
> +
> +void dell_privacy_process_event(int type, int code, int status)
> +{
> +	struct privacy_wmi_data *priv;
> +	const struct key_entry *key;
> +
> +	mutex_lock(&list_mutex);
> +	priv = list_first_entry_or_null(&wmi_list,
> +			struct privacy_wmi_data,
> +			list);
> +	if (!priv) {
> +		pr_err("dell privacy priv is NULL\n");
> +		goto error;
> +	}
> +	key = sparse_keymap_entry_from_scancode(priv->input_dev, (type << 16)|code);

missing spaces, does this even pass with checkpatch.pl?

> +	if (!key) {
> +		dev_dbg(&priv->wdev->dev, "Unknown key with type 0x%04x and code 0x%04x pressed\n",
> +				type, code);
> +		goto error;
> +	}
> +	switch (code) {
> +	case DELL_PRIVACY_TYPE_AUDIO: /* Mic mute */
> +		priv->last_status = status;
> +		sparse_keymap_report_entry(priv->input_dev, key, 1, true);
> +		break;
> +	case DELL_PRIVACY_TYPE_CAMERA: /* Camera mute */

Never seen anyone 'mute' their camera? 'switch off' or 'disable'?

> +		priv->last_status = status;
> +		sparse_keymap_report_entry(priv->input_dev, key, 1, true);
> +		break;
> +	default:
> +			dev_dbg(&priv->wdev->dev, "unknown event type 0x%04x 0x%04x",
> +					type, code);
> +	}
> +error:
> +	mutex_unlock(&list_mutex);
> +}
> +EXPORT_SYMBOL_GPL(dell_privacy_process_event);

[...]

> +/*
> + * 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) {
> +		pr_err("dell privacy priv is NULL\n");
> +		return -EINVAL;
> +	}

can this happen? when would this pointer be NULL?

> +	/* 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");
> +		ret = -EIO;
> +		privacy_valid = ret;
> +		return ret;
> +	}
> +
> +	if (obj_present->type != ACPI_TYPE_BUFFER) {
> +		dev_err(&wdev->dev, "Binary MOF is not a buffer!\n");
> +		ret = -EIO;
> +		privacy_valid = ret;
> +		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;
> +		privacy_valid = ret;
> +		goto obj_free;
> +	}
> +	buffer = (u32 *)obj_present->buffer.pointer;
> +	priv->features_present = buffer[0];
> +	priv->last_status = buffer[1];
> +	privacy_valid = 0;
> +
> +obj_free:
> +	kfree(obj_present);
> +	return ret;
> +}
> +
> +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, pos = 0;
> +
> +	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) +
> +			1,

same line?

> +			sizeof(struct key_entry), GFP_KERNEL);
> +	if (!keymap) {
> +		ret = -ENOMEM;
> +		goto err_free_dev;
> +	}
> +	/* 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[pos] = dell_wmi_keymap_type_0012[i];
> +		keymap[pos].code |= (0x0012 << 16);
> +		pos++;
> +	}
> +	ret = sparse_keymap_setup(priv->input_dev, keymap, NULL);
> +	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;
> +	if (input_register_device(priv->input_dev)) {
> +		pr_debug("input_register_device failed to register!\n");
> +		goto err_free_keymap;
> +	}
> +	mutex_lock(&list_mutex);
> +	list_add_tail(&priv->list, &wmi_list);
> +	mutex_unlock(&list_mutex);
> +	if (get_current_status(priv->wdev))
> +		goto err_free_input;
> +	ret = devm_device_add_group(&wdev->dev, &privacy_attribute_group);
> +	if (ret)
> +		goto err_free_input;
> +	kfree(keymap);
> +	return 0;

having a set of newlines wouldn't hurt, thsi is not very easy to read 
and split in logical sections...

> +
> +err_free_input:
> +	input_unregister_device(priv->input_dev);
> +err_free_keymap:
> +	privacy_valid = -ENODEV;
> +	kfree(keymap);
> +err_free_dev:
> +	input_free_device(priv->input_dev);
> +	return ret;
> +}
> +
> +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);
> +	privacy_valid = -ENODEV;
> +	input_unregister_device(priv->input_dev);
> +
> +	return 0;
> +}

[...]

> +		case 0x0012:
> +#if IS_ENABLED(CONFIG_DELL_PRIVACY)
> +			err = dell_privacy_valid();
> +			if (err == 0) {
> +				dell_privacy_process_event(buffer_entry[1],
> +						buffer_entry[3], buffer_entry[4]);
> +			} else {
> +				if (len > 2)
> +					dell_wmi_process_key(wdev, buffer_entry[1],
> +							buffer_entry[2]);
> +				/* Extended data is currently ignored */
> +			}
> +#else
> +			if (len > 2)
> +				dell_wmi_process_key(wdev, buffer_entry[1],
> +						buffer_entry[2]);
> +			/* Extended data is currently ignored */
> +#endif

this doesn't look very nice, can we avoid the duplication?

> +			break;
>   		default: /* Unknown event */
>   			pr_info("Unknown WMI event type 0x%x\n",
>   				(int)buffer_entry[1]);
>
Perry Yuan Jan. 16, 2021, 3:10 p.m. UTC | #3
On 2021/1/13 1:39, Randy Dunlap wrote:

> On 1/12/21 9:17 AM, Perry Yuan wrote:
>> +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
>> +	select DELL_WMI
>> +	help
>> +	This driver provides support for the "Dell Hardware Privacy" feature
>> +	of Dell laptops.
>> +	Support for a micmute and camera mute privacy will be provided as
>> +	hardware button Ctrl+F4 and Ctrl+F9 hotkey
> 	End above with a period '.' please.
>
>> +
>> +	To compile this driver as a module, choose M here: the module will
>> +	be called dell_privacy.
> Please follow coding-style for Kconfig files:
>
> from Documentation/process/coding-style.rst, section 10):
>
> For all of the Kconfig* configuration files throughout the source tree,
> the indentation is somewhat different.  Lines under a ``config`` definition
> are indented with one tab, while help text is indented an additional two
> spaces.
>
>
> thanks.

Thanks for your review feedback.

I will fix this in V4 patch.
Perry Yuan Feb. 14, 2021, 7:23 a.m. UTC | #4
Hi Randy.

On 2021/1/13 1:39, Randy Dunlap wrote:
> On 1/12/21 9:17 AM, Perry Yuan wrote:
>> +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
>> +	select DELL_WMI
>> +	help
>> +	This driver provides support for the "Dell Hardware Privacy" feature
>> +	of Dell laptops.
>> +	Support for a micmute and camera mute privacy will be provided as
>> +	hardware button Ctrl+F4 and Ctrl+F9 hotkey
> 
> 	End above with a period '.' please.
> 
>> +
>> +	To compile this driver as a module, choose M here: the module will
>> +	be called dell_privacy.
> 
> Please follow coding-style for Kconfig files:
> 
> from Documentation/process/coding-style.rst, section 10):
> 
> For all of the Kconfig* configuration files throughout the source tree,
> the indentation is somewhat different.  Lines under a ``config`` definition
> are indented with one tab, while help text is indented an additional two
> spaces.
> 
> 
> thanks.
> 

Thank you for the review.
Format checked again and will be updated in V4.
Perry Yuan Feb. 16, 2021, 6:48 a.m. UTC | #5
Hi Pierre:
thanks for the review effort.
On 2021/1/13 3:00, Pierre-Louis Bossart wrote:
> 
> 
> On 1/12/21 11:17 AM, 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
>> enabled, 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 emmit
>> SW_CAMERA_LENS_COVER event while the camera lens shutter will be
>> changed by EC & hw(hadware) control
> 
> It wouldn't hurt to use capital letters and punctuation, it helps with 
> readility..
> 
I will try to improve the description in V4
> [...]
> 
>> diff --git a/drivers/platform/x86/dell-laptop.c 
>> b/drivers/platform/x86/dell-laptop.c
>> index 70edc5bb3a14..2fea1f34fcf9 100644
>> --- a/drivers/platform/x86/dell-laptop.c
>> +++ b/drivers/platform/x86/dell-laptop.c
>> @@ -30,6 +30,7 @@
>>   #include <acpi/video.h>
>>   #include "dell-rbtn.h"
>>   #include "dell-smbios.h"
>> +#include "dell-privacy-wmi.h"
>>   struct quirk_entry {
>>       bool touchpad_led;
>> @@ -90,6 +91,7 @@ static struct rfkill *wifi_rfkill;
>>   static struct rfkill *bluetooth_rfkill;
>>   static struct rfkill *wwan_rfkill;
>>   static bool force_rfkill;
>> +static bool privacy_valid;
> 
> why is this variable needed? Was the intent to have a kernel parameter 
> here?
The var is used to mark if the Dell privacy wmi  driver was loaded 
successfully for now,if privacy loaded,the micmute_led_cdev.brightness
will not be registered by dell-laptop, it will be in dell-privacy-acpi
file using dell_privacy_leds_setup to register the led class.

> 
>>   module_param(force_rfkill, bool, 0444);
>>   MODULE_PARM_DESC(force_rfkill, "enable rfkill on non whitelisted 
>> models");
>> @@ -2205,11 +2207,18 @@ 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)) {
>> -        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;
>> +            dell_smbios_find_token(GLOBAL_MIC_MUTE_ENABLE)) {
>> +#if IS_ENABLED(CONFIG_DELL_PRIVACY)
>> +        ret = dell_privacy_valid();
>> +        if (!ret)
>> +            privacy_valid = true;
>> +#endif
>> +        if (!privacy_valid) {
> 
> if it was intended to be used as a kernel parameter it's not done the 
> right way: the value set by the user would be ignored...
The privacy_valid value will be retrieved from dell-privacy-wmi showing 
if the privacy driver loaded.
> 
>> +            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;
>> +        }
>>       }
>>       if (acpi_video_get_backlight_type() != acpi_backlight_vendor)
>> @@ -2257,7 +2266,8 @@ static int __init dell_init(void)
>>   fail_get_brightness:
>>       backlight_device_unregister(dell_backlight_device);
>>   fail_backlight:
>> -    led_classdev_unregister(&micmute_led_cdev);
>> +    if (!privacy_valid)
>> +        led_classdev_unregister(&micmute_led_cdev);
>>   fail_led:
>>       dell_cleanup_rfkill();
>>   fail_rfkill:
>> @@ -2278,7 +2288,8 @@ 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 (!privacy_valid)
>> +        led_classdev_unregister(&micmute_led_cdev);
>>       dell_cleanup_rfkill();
>>       if (platform_device) {
>>           platform_device_unregister(platform_device);
>> diff --git a/drivers/platform/x86/dell-privacy-acpi.c 
>> b/drivers/platform/x86/dell-privacy-acpi.c
>> new file mode 100644
>> index 000000000000..df6a86e1345c
>> --- /dev/null
>> +++ b/drivers/platform/x86/dell-privacy-acpi.c
>> @@ -0,0 +1,167 @@
>> +// 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/bits.h>
>> +#include <linux/device.h>
>> +#include <linux/fs.h>
>> +#include <linux/kernel.h>
>> +#include <linux/leds.h>
>> +#include <linux/module.h>
>> +#include <linux/mutex.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/string.h>
>> +#include <linux/sysfs.h>
>> +#include <linux/slab.h>
>> +#include <linux/types.h>
>> +#include <linux/wmi.h>
>> +
>> +#include "dell-privacy-wmi.h"
>> +
>> +#define PRIVACY_PLATFORM_NAME    "dell-privacy-acpi"
>> +#define DELL_PRIVACY_GUID    "6932965F-1671-4CEB-B988-D3AB0A901919"
>> +
>> +struct privacy_acpi_priv {
>> +    struct device *dev;
>> +    struct platform_device *platform_device;
>> +    struct led_classdev cdev;
>> +};
>> +static struct privacy_acpi_priv *privacy_acpi;
>> +
>> +static int dell_privacy_micmute_led_set(struct led_classdev *led_cdev,
>> +        enum led_brightness brightness)
>> +{
>> +    struct privacy_acpi_priv *priv = privacy_acpi;
>> +    acpi_status status;
>> +    acpi_handle handle;
>> +    char *acpi_method;
>> +
>> +    handle = ec_get_handle();
>> +    if (!handle)
>> +        return -EIO;
>> +    acpi_method = "ECAK";
>> +    status = acpi_evaluate_object(handle, acpi_method, NULL, NULL);
>> +    if (ACPI_FAILURE(status)) {
>> +        dev_err(priv->dev, "Error setting privacy EC ack value: %s\n",
>> +                acpi_format_exception(status));
>> +        return -EIO;
>> +    }
>> +    return 0;
>> +}
>> +
>> +static int dell_privacy_acpi_remove(struct platform_device *pdev)
>> +{
>> +    struct privacy_acpi_priv *priv = dev_get_drvdata(privacy_acpi->dev);
>> +
>> +    led_classdev_unregister(&priv->cdev);
>> +
>> +    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_acpi_priv *priv = dev_get_drvdata(dev);
>> +    int ret = 0;
>> +
>> +    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);
>> +    ret = devm_led_classdev_register(dev, &priv->cdev);
>> +    if (ret < 0)
>> +        return ret;
>> +    return 0;
>> +}
>> +
>> +static int dell_privacy_acpi_probe(struct platform_device *pdev)
>> +{
>> +    platform_set_drvdata(pdev, privacy_acpi);
>> +    privacy_acpi->dev = &pdev->dev;
>> +    privacy_acpi->platform_device = pdev;
>> +    return 0;
>> +}
>> +
>> +static const struct acpi_device_id privacy_acpi_device_ids[] = {
>> +    {"PNP0C09", 0},
>> +    { },
>> +};
>> +MODULE_DEVICE_TABLE(acpi, privacy_acpi_device_ids);
>> +
>> +static struct platform_driver dell_privacy_platform_drv = {
>> +    .driver = {
>> +        .name = PRIVACY_PLATFORM_NAME,
>> +        .acpi_match_table = ACPI_PTR(privacy_acpi_device_ids),
>> +    },
> 
> no .probe?
Originally i added the probe here, but it cause the driver  .probe 
called twice. after i use platform_driver_probe to register the driver 
loading process, the duplicated probe issue resolved.

I
> 
>> +    .remove = dell_privacy_acpi_remove,
>> +};
>> +
>> +int __init dell_privacy_acpi_init(void)
>> +{
>> +    int err;
>> +    struct platform_device *pdev;
>> +    int privacy_capable = wmi_has_guid(DELL_PRIVACY_GUID);
>> +
>> +    if (!wmi_has_guid(DELL_PRIVACY_GUID))
>> +        return -ENODEV;
>> +
>> +    privacy_acpi = kzalloc(sizeof(*privacy_acpi), GFP_KERNEL);
>> +    if (!privacy_acpi)
>> +        return -ENOMEM;
>> +
>> +    pdev = platform_device_register_simple(
>> +            PRIVACY_PLATFORM_NAME, PLATFORM_DEVID_NONE, NULL, 0);
>> +    if (IS_ERR(pdev)) {
>> +        err = PTR_ERR(pdev);
>> +        goto pdev_err;
>> +    }
>> +    err = platform_driver_probe(&dell_privacy_platform_drv,
>> +            dell_privacy_acpi_probe);
>> +    if (err)
>> +        goto pdrv_err;
> 
> why is the probe done here? Put differently, what prevents you from 
> using a 'normal' platform driver, and do the leds_setup in the .probe()?
At first ,I used the normal platform driver framework, however tt cause 
the driver  .probe called twice. after i use platform_driver_probe to 
register the driver loading process, the duplicated probe issue resolved.

> 
>> +
>> +    err = dell_privacy_leds_setup(&pdev->dev);
>> +    if (err < 0)
>> +        goto pdrv_err;
>> +
>> +    return 0;
>> +
>> +pdrv_err:
>> +    platform_device_unregister(pdev);
>> +pdev_err:
>> +    kfree(privacy_acpi);
>> +    return err;
>> +}
>> +
>> +void __exit dell_privacy_acpi_exit(void)
>> +{
>> +    struct platform_device *pdev = 
>> to_platform_device(privacy_acpi->dev);
>> +
>> +    platform_device_unregister(pdev);
>> +    platform_driver_unregister(&dell_privacy_platform_drv);
>> +    kfree(privacy_acpi);
>> +}
>> +
>> +MODULE_AUTHOR("Perry Yuan <perry_yuan@dell.com>");
>> +MODULE_DESCRIPTION("DELL Privacy ACPI Driver");
>> +MODULE_LICENSE("GPL");
>> diff --git a/drivers/platform/x86/dell-privacy-wmi.c 
>> b/drivers/platform/x86/dell-privacy-wmi.c
>> new file mode 100644
>> index 000000000000..432a3f4ed226
>> --- /dev/null
>> +++ b/drivers/platform/x86/dell-privacy-wmi.c
>> @@ -0,0 +1,320 @@
>> +// 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/input.h>
>> +#include <linux/input/sparse-keymap.h>
>> +#include <linux/list.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 PRIVACY_SCREEN_STATUS        BIT(2)
>> +
>> +static int privacy_valid = -EPROBE_DEFER;
> 
> this is set to -ENODEV on remove. that looks odd to me.
> 
>> +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;
>> +    u32 features_present;
>> +    u32 last_status;
>> +};
>> +
>> +/*
>> + * 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},
>> +};
>> +
>> +int dell_privacy_valid(void)
>> +{
>> +    int ret;
>> +
>> +    ret = wmi_has_guid(DELL_PRIVACY_GUID);
>> +    if (!ret)
>> +        return -ENODEV;
>> +    ret = privacy_valid;
>> +    return ret;
> 
> return privacy_valid?
> 
>> +}
>> +EXPORT_SYMBOL_GPL(dell_privacy_valid);
>> +
>> +void dell_privacy_process_event(int type, int code, int status)
>> +{
>> +    struct privacy_wmi_data *priv;
>> +    const struct key_entry *key;
>> +
>> +    mutex_lock(&list_mutex);
>> +    priv = list_first_entry_or_null(&wmi_list,
>> +            struct privacy_wmi_data,
>> +            list);
>> +    if (!priv) {
>> +        pr_err("dell privacy priv is NULL\n");
>> +        goto error;
>> +    }
>> +    key = sparse_keymap_entry_from_scancode(priv->input_dev, (type << 
>> 16)|code);
> 
> missing spaces, does this even pass with checkpatch.pl
> 
>> +    if (!key) {
>> +        dev_dbg(&priv->wdev->dev, "Unknown key with type 0x%04x and 
>> code 0x%04x pressed\n",
>> +                type, code);
>> +        goto error;
>> +    }
>> +    switch (code) {
>> +    case DELL_PRIVACY_TYPE_AUDIO: /* Mic mute */
>> +        priv->last_status = status;
>> +        sparse_keymap_report_entry(priv->input_dev, key, 1, true);
>> +        break;
>> +    case DELL_PRIVACY_TYPE_CAMERA: /* Camera mute */
> 
> Never seen anyone 'mute' their camera? 'switch off' or 'disable'?
Camera Mute will be added to Dell platforms very soon.
It needs to add this for that coming camera mute privacy feature.
> 
>> +        priv->last_status = status;
>> +        sparse_keymap_report_entry(priv->input_dev, key, 1, true);
>> +        break;
>> +    default:
>> +            dev_dbg(&priv->wdev->dev, "unknown event type 0x%04x 
>> 0x%04x",
>> +                    type, code);
>> +    }
>> +error:
>> +    mutex_unlock(&list_mutex);
>> +}
>> +EXPORT_SYMBOL_GPL(dell_privacy_process_event);
> 
> [...]
> 
>> +/*
>> + * 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) {
>> +        pr_err("dell privacy priv is NULL\n");
>> +        return -EINVAL;
>> +    }
> 
> can this happen? when would this pointer be NULL?
Hopefully not happening, but i want to make sure the priv is not NULL,
Otherwise it will cause kernel oops or panic.
In that case, i would prefer to check the priv data again safely.
> 
>> +    /* 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");
>> +        ret = -EIO;
>> +        privacy_valid = ret;
>> +        return ret;
>> +    }
>> +
>> +    if (obj_present->type != ACPI_TYPE_BUFFER) {
>> +        dev_err(&wdev->dev, "Binary MOF is not a buffer!\n");
>> +        ret = -EIO;
>> +        privacy_valid = ret;
>> +        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;
>> +        privacy_valid = ret;
>> +        goto obj_free;
>> +    }
>> +    buffer = (u32 *)obj_present->buffer.pointer;
>> +    priv->features_present = buffer[0];
>> +    priv->last_status = buffer[1];
>> +    privacy_valid = 0;
>> +
>> +obj_free:
>> +    kfree(obj_present);
>> +    return ret;
>> +}
>> +
>> +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, pos = 0;
>> +
>> +    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) +
>> +            1,
> 
> same line?
Yes,it is the same line
If it is not good shape. i changed like this is also OK for me.


         keymap = kcalloc(ARRAY_SIZE(dell_wmi_keymap_type_0012) + 1,
                         sizeof(struct key_entry), GFP_KERNEL);

> 
>> +            sizeof(struct key_entry), GFP_KERNEL);
>> +    if (!keymap) {
>> +        ret = -ENOMEM;
>> +        goto err_free_dev;
>> +    }
>> +    /* 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[pos] = dell_wmi_keymap_type_0012[i];
>> +        keymap[pos].code |= (0x0012 << 16);
>> +        pos++;
>> +    }
>> +    ret = sparse_keymap_setup(priv->input_dev, keymap, NULL);
>> +    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;
>> +    if (input_register_device(priv->input_dev)) {
>> +        pr_debug("input_register_device failed to register!\n");
>> +        goto err_free_keymap;
>> +    }
>> +    mutex_lock(&list_mutex);
>> +    list_add_tail(&priv->list, &wmi_list);
>> +    mutex_unlock(&list_mutex);
>> +    if (get_current_status(priv->wdev))
>> +        goto err_free_input;
>> +    ret = devm_device_add_group(&wdev->dev, &privacy_attribute_group);
>> +    if (ret)
>> +        goto err_free_input;
>> +    kfree(keymap);
>> +    return 0;
> 
> having a set of newlines wouldn't hurt, thsi is not very easy to read 
> and split in logical sections...
> 
Agreed,add some new lines to make the section more logically to review.
>> +
>> +err_free_input:
>> +    input_unregister_device(priv->input_dev);
>> +err_free_keymap:
>> +    privacy_valid = -ENODEV;
>> +    kfree(keymap);
>> +err_free_dev:
>> +    input_free_device(priv->input_dev);
>> +    return ret;
>> +}
>> +
>> +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);
>> +    privacy_valid = -ENODEV;
>> +    input_unregister_device(priv->input_dev);
>> +
>> +    return 0;
>> +}
> 
> [...]
> 
>> +        case 0x0012:
>> +#if IS_ENABLED(CONFIG_DELL_PRIVACY)
>> +            err = dell_privacy_valid();
>> +            if (err == 0) {
>> +                dell_privacy_process_event(buffer_entry[1],
>> +                        buffer_entry[3], buffer_entry[4]);
>> +            } else {
>> +                if (len > 2)
>> +                    dell_wmi_process_key(wdev, buffer_entry[1],
>> +                            buffer_entry[2]);
>> +                /* Extended data is currently ignored */
>> +            }
>> +#else
>> +            if (len > 2)
>> +                dell_wmi_process_key(wdev, buffer_entry[1],
>> +                        buffer_entry[2]);
>> +            /* Extended data is currently ignored */
>> +#endif
> 
> this doesn't look very nice, can we avoid the duplication?
Sure, I clear the duplicated comments.
> 
>> +            break;
>>           default: /* Unknown event */
>>               pr_info("Unknown WMI event type 0x%x\n",
>>                   (int)buffer_entry[1]);
>>
Pierre-Louis Bossart Feb. 16, 2021, 2:56 p.m. UTC | #6
>>> +static const struct acpi_device_id privacy_acpi_device_ids[] = {
>>> +    {"PNP0C09", 0},
>>> +    { },
>>> +};
>>> +MODULE_DEVICE_TABLE(acpi, privacy_acpi_device_ids);
>>> +
>>> +static struct platform_driver dell_privacy_platform_drv = {
>>> +    .driver = {
>>> +        .name = PRIVACY_PLATFORM_NAME,
>>> +        .acpi_match_table = ACPI_PTR(privacy_acpi_device_ids),
>>> +    },
>>
>> no .probe?
> Originally i added the probe here, but it cause the driver  .probe 
> called twice. after i use platform_driver_probe to register the driver 
> loading process, the duplicated probe issue resolved.
> 
> I
>>
>>> +    .remove = dell_privacy_acpi_remove,
>>> +};
>>> +
>>> +int __init dell_privacy_acpi_init(void)
>>> +{
>>> +    int err;
>>> +    struct platform_device *pdev;
>>> +    int privacy_capable = wmi_has_guid(DELL_PRIVACY_GUID);
>>> +
>>> +    if (!wmi_has_guid(DELL_PRIVACY_GUID))
>>> +        return -ENODEV;
>>> +
>>> +    privacy_acpi = kzalloc(sizeof(*privacy_acpi), GFP_KERNEL);
>>> +    if (!privacy_acpi)
>>> +        return -ENOMEM;
>>> +
>>> +    pdev = platform_device_register_simple(
>>> +            PRIVACY_PLATFORM_NAME, PLATFORM_DEVID_NONE, NULL, 0);
>>> +    if (IS_ERR(pdev)) {
>>> +        err = PTR_ERR(pdev);
>>> +        goto pdev_err;
>>> +    }
>>> +    err = platform_driver_probe(&dell_privacy_platform_drv,
>>> +            dell_privacy_acpi_probe);
>>> +    if (err)
>>> +        goto pdrv_err;
>>
>> why is the probe done here? Put differently, what prevents you from 
>> using a 'normal' platform driver, and do the leds_setup in the .probe()?
> At first ,I used the normal platform driver framework, however tt cause 
> the driver  .probe called twice. after i use platform_driver_probe to 
> register the driver loading process, the duplicated probe issue resolved.

This sounds very odd...

this looks like a conflict with the ACPI subsystem finding a device and 
probing the driver that's associated with the PNP0C09 HID, and then this 
module __init  creating a device manually which leads to a second probe

Neither the platform_device_register_simple() nor 
platform_driver_probe() seem necessary?
Perry Yuan Feb. 17, 2021, 12:47 p.m. UTC | #7
Hi Pierre:
On 2021/2/16 22:56, Pierre-Louis Bossart wrote:
> 
>>>> +static const struct acpi_device_id privacy_acpi_device_ids[] = {
>>>> +    {"PNP0C09", 0},
>>>> +    { },
>>>> +};
>>>> +MODULE_DEVICE_TABLE(acpi, privacy_acpi_device_ids);
>>>> +
>>>> +static struct platform_driver dell_privacy_platform_drv = {
>>>> +    .driver = {
>>>> +        .name = PRIVACY_PLATFORM_NAME,
>>>> +        .acpi_match_table = ACPI_PTR(privacy_acpi_device_ids),
>>>> +    },
>>>
>>> no .probe?
>> Originally i added the probe here, but it cause the driver  .probe 
>> called twice. after i use platform_driver_probe to register the driver 
>> loading process, the duplicated probe issue resolved.
>>
>> I
>>>
>>>> +    .remove = dell_privacy_acpi_remove,
>>>> +};
>>>> +
>>>> +int __init dell_privacy_acpi_init(void)
>>>> +{
>>>> +    int err;
>>>> +    struct platform_device *pdev;
>>>> +    int privacy_capable = wmi_has_guid(DELL_PRIVACY_GUID);
>>>> +
>>>> +    if (!wmi_has_guid(DELL_PRIVACY_GUID))
>>>> +        return -ENODEV;
>>>> +
>>>> +    privacy_acpi = kzalloc(sizeof(*privacy_acpi), GFP_KERNEL);
>>>> +    if (!privacy_acpi)
>>>> +        return -ENOMEM;
>>>> +
>>>> +    pdev = platform_device_register_simple(
>>>> +            PRIVACY_PLATFORM_NAME, PLATFORM_DEVID_NONE, NULL, 0);
>>>> +    if (IS_ERR(pdev)) {
>>>> +        err = PTR_ERR(pdev);
>>>> +        goto pdev_err;
>>>> +    }
>>>> +    err = platform_driver_probe(&dell_privacy_platform_drv,
>>>> +            dell_privacy_acpi_probe);
>>>> +    if (err)
>>>> +        goto pdrv_err;
>>>
>>> why is the probe done here? Put differently, what prevents you from 
>>> using a 'normal' platform driver, and do the leds_setup in the .probe()?
>> At first ,I used the normal platform driver framework, however tt 
>> cause the driver  .probe called twice. after i use 
>> platform_driver_probe to register the driver loading process, the 
>> duplicated probe issue resolved.
> 
> This sounds very odd...
> 
> this looks like a conflict with the ACPI subsystem finding a device and 
> probing the driver that's associated with the PNP0C09 HID, and then this 
> module __init  creating a device manually which leads to a second probe
> 
> Neither the platform_device_register_simple() nor 
> platform_driver_probe() seem necessary?Because this privacy acpi driver file has dependency on the ec handle, 
so i want to determine if the driver can be loaded basing on the EC ID 
PNP0C09 matching.

So far,It works well for me to register the privacy driver with  the 
register sequence.
Dose it hurt to keep current registering process with 
platform_driver_probe used?

Perry
Pierre-Louis Bossart Feb. 17, 2021, 2:23 p.m. UTC | #8
On 2/17/21 6:47 AM, Perry Yuan wrote:
> Hi Pierre:
> On 2021/2/16 22:56, Pierre-Louis Bossart wrote:
>>
>>>>> +static const struct acpi_device_id privacy_acpi_device_ids[] = {
>>>>> +    {"PNP0C09", 0},
>>>>> +    { },
>>>>> +};
>>>>> +MODULE_DEVICE_TABLE(acpi, privacy_acpi_device_ids);
>>>>> +
>>>>> +static struct platform_driver dell_privacy_platform_drv = {
>>>>> +    .driver = {
>>>>> +        .name = PRIVACY_PLATFORM_NAME,
>>>>> +        .acpi_match_table = ACPI_PTR(privacy_acpi_device_ids),
>>>>> +    },
>>>>
>>>> no .probe?
>>> Originally i added the probe here, but it cause the driver  .probe 
>>> called twice. after i use platform_driver_probe to register the 
>>> driver loading process, the duplicated probe issue resolved.
>>>
>>> I
>>>>
>>>>> +    .remove = dell_privacy_acpi_remove,
>>>>> +};
>>>>> +
>>>>> +int __init dell_privacy_acpi_init(void)
>>>>> +{
>>>>> +    int err;
>>>>> +    struct platform_device *pdev;
>>>>> +    int privacy_capable = wmi_has_guid(DELL_PRIVACY_GUID);
>>>>> +
>>>>> +    if (!wmi_has_guid(DELL_PRIVACY_GUID))
>>>>> +        return -ENODEV;
>>>>> +
>>>>> +    privacy_acpi = kzalloc(sizeof(*privacy_acpi), GFP_KERNEL);
>>>>> +    if (!privacy_acpi)
>>>>> +        return -ENOMEM;
>>>>> +
>>>>> +    pdev = platform_device_register_simple(
>>>>> +            PRIVACY_PLATFORM_NAME, PLATFORM_DEVID_NONE, NULL, 0);
>>>>> +    if (IS_ERR(pdev)) {
>>>>> +        err = PTR_ERR(pdev);
>>>>> +        goto pdev_err;
>>>>> +    }
>>>>> +    err = platform_driver_probe(&dell_privacy_platform_drv,
>>>>> +            dell_privacy_acpi_probe);
>>>>> +    if (err)
>>>>> +        goto pdrv_err;
>>>>
>>>> why is the probe done here? Put differently, what prevents you from 
>>>> using a 'normal' platform driver, and do the leds_setup in the 
>>>> .probe()?
>>> At first ,I used the normal platform driver framework, however tt 
>>> cause the driver  .probe called twice. after i use 
>>> platform_driver_probe to register the driver loading process, the 
>>> duplicated probe issue resolved.
>>
>> This sounds very odd...
>>
>> this looks like a conflict with the ACPI subsystem finding a device 
>> and probing the driver that's associated with the PNP0C09 HID, and 
>> then this module __init  creating a device manually which leads to a 
>> second probe
>>
>> Neither the platform_device_register_simple() nor 
>> platform_driver_probe() seem necessary?Because this privacy acpi 
>> driver file has dependency on the ec handle, 
> so i want to determine if the driver can be loaded basing on the EC ID 
> PNP0C09 matching.
> 
> So far,It works well for me to register the privacy driver with  the 
> register sequence.
> Dose it hurt to keep current registering process with 
> platform_driver_probe used?

Sorry, I don't understand why you need to list PNP0C09 HID in a matching 
table if it's not used to probe anything.

The purpose of those matching tables is that when this HID is found, the 
core will invoke the probe callback with no need for any manual 
intervention.

If you want to do things manually with the module init, that's fine, 
it's the combination of the two that I find questionable.

It's like having both a manual and automatic transmission in a car, with 
the automatic transmission not coupled to the wheels.
diff mbox series

Patch

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 91e6176cdfbd..9d5cc2454b3e 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -491,6 +491,23 @@  config DELL_WMI_LED
 	  This adds support for the Latitude 2100 and similar
 	  notebooks that have an external LED.
 
+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
+	select DELL_WMI
+	help
+	This driver provides support for the "Dell Hardware Privacy" feature
+	of Dell laptops.
+	Support for a micmute and camera mute privacy will be provided as
+	hardware button Ctrl+F4 and Ctrl+F9 hotkey
+
+	To compile this driver as a module, choose M here: the module will
+	be called dell_privacy.
+
 config AMILO_RFKILL
 	tristate "Fujitsu-Siemens Amilo rfkill support"
 	depends on RFKILL
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 581475f59819..18c430456de7 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -51,7 +51,9 @@  obj-$(CONFIG_DELL_WMI_DESCRIPTOR)	+= dell-wmi-descriptor.o
 obj-$(CONFIG_DELL_WMI_AIO)		+= dell-wmi-aio.o
 obj-$(CONFIG_DELL_WMI_LED)		+= dell-wmi-led.o
 obj-$(CONFIG_DELL_WMI_SYSMAN)		+= dell-wmi-sysman/
-
+obj-$(CONFIG_DELL_PRIVACY)              += dell-privacy.o
+dell-privacy-objs                       := dell-privacy-wmi.o \
+	                                   dell-privacy-acpi.o
 # Fujitsu
 obj-$(CONFIG_AMILO_RFKILL)	+= amilo-rfkill.o
 obj-$(CONFIG_FUJITSU_LAPTOP)	+= fujitsu-laptop.o
diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
index 70edc5bb3a14..2fea1f34fcf9 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
@@ -30,6 +30,7 @@ 
 #include <acpi/video.h>
 #include "dell-rbtn.h"
 #include "dell-smbios.h"
+#include "dell-privacy-wmi.h"
 
 struct quirk_entry {
 	bool touchpad_led;
@@ -90,6 +91,7 @@  static struct rfkill *wifi_rfkill;
 static struct rfkill *bluetooth_rfkill;
 static struct rfkill *wwan_rfkill;
 static bool force_rfkill;
+static bool privacy_valid;
 
 module_param(force_rfkill, bool, 0444);
 MODULE_PARM_DESC(force_rfkill, "enable rfkill on non whitelisted models");
@@ -2205,11 +2207,18 @@  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)) {
-		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;
+			dell_smbios_find_token(GLOBAL_MIC_MUTE_ENABLE)) {
+#if IS_ENABLED(CONFIG_DELL_PRIVACY)
+		ret = dell_privacy_valid();
+		if (!ret)
+			privacy_valid = true;
+#endif
+		if (!privacy_valid) {
+			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;
+		}
 	}
 
 	if (acpi_video_get_backlight_type() != acpi_backlight_vendor)
@@ -2257,7 +2266,8 @@  static int __init dell_init(void)
 fail_get_brightness:
 	backlight_device_unregister(dell_backlight_device);
 fail_backlight:
-	led_classdev_unregister(&micmute_led_cdev);
+	if (!privacy_valid)
+		led_classdev_unregister(&micmute_led_cdev);
 fail_led:
 	dell_cleanup_rfkill();
 fail_rfkill:
@@ -2278,7 +2288,8 @@  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 (!privacy_valid)
+		led_classdev_unregister(&micmute_led_cdev);
 	dell_cleanup_rfkill();
 	if (platform_device) {
 		platform_device_unregister(platform_device);
diff --git a/drivers/platform/x86/dell-privacy-acpi.c b/drivers/platform/x86/dell-privacy-acpi.c
new file mode 100644
index 000000000000..df6a86e1345c
--- /dev/null
+++ b/drivers/platform/x86/dell-privacy-acpi.c
@@ -0,0 +1,167 @@ 
+// 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/bits.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/wmi.h>
+
+#include "dell-privacy-wmi.h"
+
+#define PRIVACY_PLATFORM_NAME	"dell-privacy-acpi"
+#define DELL_PRIVACY_GUID	"6932965F-1671-4CEB-B988-D3AB0A901919"
+
+struct privacy_acpi_priv {
+	struct device *dev;
+	struct platform_device *platform_device;
+	struct led_classdev cdev;
+};
+static struct privacy_acpi_priv *privacy_acpi;
+
+static int dell_privacy_micmute_led_set(struct led_classdev *led_cdev,
+		enum led_brightness brightness)
+{
+	struct privacy_acpi_priv *priv = privacy_acpi;
+	acpi_status status;
+	acpi_handle handle;
+	char *acpi_method;
+
+	handle = ec_get_handle();
+	if (!handle)
+		return -EIO;
+	acpi_method = "ECAK";
+	status = acpi_evaluate_object(handle, acpi_method, NULL, NULL);
+	if (ACPI_FAILURE(status)) {
+		dev_err(priv->dev, "Error setting privacy EC ack value: %s\n",
+				acpi_format_exception(status));
+		return -EIO;
+	}
+	return 0;
+}
+
+static int dell_privacy_acpi_remove(struct platform_device *pdev)
+{
+	struct privacy_acpi_priv *priv = dev_get_drvdata(privacy_acpi->dev);
+
+	led_classdev_unregister(&priv->cdev);
+
+	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_acpi_priv *priv = dev_get_drvdata(dev);
+	int ret = 0;
+
+	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);
+	ret = devm_led_classdev_register(dev, &priv->cdev);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+static int dell_privacy_acpi_probe(struct platform_device *pdev)
+{
+	platform_set_drvdata(pdev, privacy_acpi);
+	privacy_acpi->dev = &pdev->dev;
+	privacy_acpi->platform_device = pdev;
+	return 0;
+}
+
+static const struct acpi_device_id privacy_acpi_device_ids[] = {
+	{"PNP0C09", 0},
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, privacy_acpi_device_ids);
+
+static struct platform_driver dell_privacy_platform_drv = {
+	.driver = {
+		.name = PRIVACY_PLATFORM_NAME,
+		.acpi_match_table = ACPI_PTR(privacy_acpi_device_ids),
+	},
+	.remove = dell_privacy_acpi_remove,
+};
+
+int __init dell_privacy_acpi_init(void)
+{
+	int err;
+	struct platform_device *pdev;
+	int privacy_capable = wmi_has_guid(DELL_PRIVACY_GUID);
+
+	if (!wmi_has_guid(DELL_PRIVACY_GUID))
+		return -ENODEV;
+
+	privacy_acpi = kzalloc(sizeof(*privacy_acpi), GFP_KERNEL);
+	if (!privacy_acpi)
+		return -ENOMEM;
+
+	pdev = platform_device_register_simple(
+			PRIVACY_PLATFORM_NAME, PLATFORM_DEVID_NONE, NULL, 0);
+	if (IS_ERR(pdev)) {
+		err = PTR_ERR(pdev);
+		goto pdev_err;
+	}
+	err = platform_driver_probe(&dell_privacy_platform_drv,
+			dell_privacy_acpi_probe);
+	if (err)
+		goto pdrv_err;
+
+	err = dell_privacy_leds_setup(&pdev->dev);
+	if (err < 0)
+		goto pdrv_err;
+
+	return 0;
+
+pdrv_err:
+	platform_device_unregister(pdev);
+pdev_err:
+	kfree(privacy_acpi);
+	return err;
+}
+
+void __exit dell_privacy_acpi_exit(void)
+{
+	struct platform_device *pdev = to_platform_device(privacy_acpi->dev);
+
+	platform_device_unregister(pdev);
+	platform_driver_unregister(&dell_privacy_platform_drv);
+	kfree(privacy_acpi);
+}
+
+MODULE_AUTHOR("Perry Yuan <perry_yuan@dell.com>");
+MODULE_DESCRIPTION("DELL Privacy ACPI Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/platform/x86/dell-privacy-wmi.c b/drivers/platform/x86/dell-privacy-wmi.c
new file mode 100644
index 000000000000..432a3f4ed226
--- /dev/null
+++ b/drivers/platform/x86/dell-privacy-wmi.c
@@ -0,0 +1,320 @@ 
+// 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/input.h>
+#include <linux/input/sparse-keymap.h>
+#include <linux/list.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 PRIVACY_SCREEN_STATUS		BIT(2)
+
+static int privacy_valid = -EPROBE_DEFER;
+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;
+	u32 features_present;
+	u32 last_status;
+};
+
+/*
+ * 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},
+};
+
+int dell_privacy_valid(void)
+{
+	int ret;
+
+	ret = wmi_has_guid(DELL_PRIVACY_GUID);
+	if (!ret)
+		return -ENODEV;
+	ret = privacy_valid;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dell_privacy_valid);
+
+void dell_privacy_process_event(int type, int code, int status)
+{
+	struct privacy_wmi_data *priv;
+	const struct key_entry *key;
+
+	mutex_lock(&list_mutex);
+	priv = list_first_entry_or_null(&wmi_list,
+			struct privacy_wmi_data,
+			list);
+	if (!priv) {
+		pr_err("dell privacy priv is NULL\n");
+		goto error;
+	}
+	key = sparse_keymap_entry_from_scancode(priv->input_dev, (type << 16)|code);
+	if (!key) {
+		dev_dbg(&priv->wdev->dev, "Unknown key with type 0x%04x and code 0x%04x pressed\n",
+				type, code);
+		goto error;
+	}
+	switch (code) {
+	case DELL_PRIVACY_TYPE_AUDIO: /* Mic mute */
+		priv->last_status = status;
+		sparse_keymap_report_entry(priv->input_dev, key, 1, true);
+		break;
+	case DELL_PRIVACY_TYPE_CAMERA: /* Camera mute */
+		priv->last_status = status;
+		sparse_keymap_report_entry(priv->input_dev, key, 1, true);
+		break;
+	default:
+			dev_dbg(&priv->wdev->dev, "unknown event type 0x%04x 0x%04x",
+					type, code);
+	}
+error:
+	mutex_unlock(&list_mutex);
+}
+EXPORT_SYMBOL_GPL(dell_privacy_process_event);
+
+static ssize_t devices_supported_show(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct privacy_wmi_data *priv = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%x\n", priv->features_present);
+}
+
+static ssize_t current_state_show(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct privacy_wmi_data *priv = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%x\n", priv->last_status);
+}
+
+static DEVICE_ATTR_RO(devices_supported);
+static DEVICE_ATTR_RO(current_state);
+
+static struct attribute *privacy_attributes[] = {
+	&dev_attr_devices_supported.attr,
+	&dev_attr_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) {
+		pr_err("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");
+		ret = -EIO;
+		privacy_valid = ret;
+		return ret;
+	}
+
+	if (obj_present->type != ACPI_TYPE_BUFFER) {
+		dev_err(&wdev->dev, "Binary MOF is not a buffer!\n");
+		ret = -EIO;
+		privacy_valid = ret;
+		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;
+		privacy_valid = ret;
+		goto obj_free;
+	}
+	buffer = (u32 *)obj_present->buffer.pointer;
+	priv->features_present = buffer[0];
+	priv->last_status = buffer[1];
+	privacy_valid = 0;
+
+obj_free:
+	kfree(obj_present);
+	return ret;
+}
+
+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, pos = 0;
+
+	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) +
+			1,
+			sizeof(struct key_entry), GFP_KERNEL);
+	if (!keymap) {
+		ret = -ENOMEM;
+		goto err_free_dev;
+	}
+	/* 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[pos] = dell_wmi_keymap_type_0012[i];
+		keymap[pos].code |= (0x0012 << 16);
+		pos++;
+	}
+	ret = sparse_keymap_setup(priv->input_dev, keymap, NULL);
+	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;
+	if (input_register_device(priv->input_dev)) {
+		pr_debug("input_register_device failed to register!\n");
+		goto err_free_keymap;
+	}
+	mutex_lock(&list_mutex);
+	list_add_tail(&priv->list, &wmi_list);
+	mutex_unlock(&list_mutex);
+	if (get_current_status(priv->wdev))
+		goto err_free_input;
+	ret = devm_device_add_group(&wdev->dev, &privacy_attribute_group);
+	if (ret)
+		goto err_free_input;
+	kfree(keymap);
+	return 0;
+
+err_free_input:
+	input_unregister_device(priv->input_dev);
+err_free_keymap:
+	privacy_valid = -ENODEV;
+	kfree(keymap);
+err_free_dev:
+	input_free_device(priv->input_dev);
+	return ret;
+}
+
+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);
+	privacy_valid = -ENODEV;
+	input_unregister_device(priv->input_dev);
+
+	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,
+};
+
+static int __init init_dell_privacy(void)
+{
+	int ret;
+
+	ret = wmi_has_guid(DELL_PRIVACY_GUID);
+	if (!ret)
+		return -ENODEV;
+
+	ret = wmi_driver_register(&dell_privacy_wmi_driver);
+	if (ret) {
+		pr_err("failed to initialize privacy wmi driver: %d\n", ret);
+		return ret;
+	}
+
+	ret = dell_privacy_acpi_init();
+	if (ret) {
+		pr_err("failed to initialize privacy acpi driver: %d\n", ret);
+		goto err_init;
+	}
+
+	return 0;
+
+err_init:
+	wmi_driver_unregister(&dell_privacy_wmi_driver);
+	return ret;
+}
+
+static void dell_privacy_wmi_exit(void)
+{
+	wmi_driver_unregister(&dell_privacy_wmi_driver);
+}
+
+static void __exit exit_dell_privacy(void)
+{
+	dell_privacy_wmi_exit();
+	dell_privacy_acpi_exit();
+}
+
+module_init(init_dell_privacy);
+module_exit(exit_dell_privacy);
+
+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-privacy-wmi.h b/drivers/platform/x86/dell-privacy-wmi.h
new file mode 100644
index 000000000000..9fa01d084f7d
--- /dev/null
+++ b/drivers/platform/x86/dell-privacy-wmi.h
@@ -0,0 +1,33 @@ 
+/* 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)
+int  dell_privacy_valid(void);
+void dell_privacy_process_event(int type, int code, int status);
+#else /* CONFIG_DELL_PRIVACY */
+static inline int dell_privacy_valid(void)
+{
+	return  -ENODEV;
+}
+
+static inline void dell_privacy_process_event(int type, int code, int status)
+{}
+#endif /* CONFIG_DELL_PRIVACY */
+
+int  dell_privacy_acpi_init(void);
+void dell_privacy_acpi_exit(void);
+
+/* DELL Privacy Type */
+enum {
+	DELL_PRIVACY_TYPE_UNKNOWN = 0x0,
+	DELL_PRIVACY_TYPE_AUDIO,
+	DELL_PRIVACY_TYPE_CAMERA,
+};
+#endif
diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c
index bbdb3e860892..93f478edf5d1 100644
--- a/drivers/platform/x86/dell-wmi.c
+++ b/drivers/platform/x86/dell-wmi.c
@@ -13,20 +13,22 @@ 
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
-#include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/dmi.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/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
 #include <linux/string.h>
-#include <linux/dmi.h>
+#include <linux/types.h>
 #include <linux/wmi.h>
 #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>");
@@ -381,6 +383,7 @@  static void dell_wmi_notify(struct wmi_device *wdev,
 	u16 *buffer_entry, *buffer_end;
 	acpi_size buffer_size;
 	int len, i;
+	int err;
 
 	if (obj->type != ACPI_TYPE_BUFFER) {
 		pr_warn("bad response type %x\n", obj->type);
@@ -427,10 +430,9 @@  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]);
+						buffer_entry[2]);
 			/* Extended data is currently ignored */
 			break;
 		case 0x0010: /* Sequence of keys pressed */
@@ -439,6 +441,25 @@  static void dell_wmi_notify(struct wmi_device *wdev,
 				dell_wmi_process_key(wdev, buffer_entry[1],
 						     buffer_entry[i]);
 			break;
+		case 0x0012:
+#if IS_ENABLED(CONFIG_DELL_PRIVACY)
+			err = dell_privacy_valid();
+			if (err == 0) {
+				dell_privacy_process_event(buffer_entry[1],
+						buffer_entry[3], buffer_entry[4]);
+			} else {
+				if (len > 2)
+					dell_wmi_process_key(wdev, buffer_entry[1],
+							buffer_entry[2]);
+				/* Extended data is currently ignored */
+			}
+#else
+			if (len > 2)
+				dell_wmi_process_key(wdev, buffer_entry[1],
+						buffer_entry[2]);
+			/* Extended data is currently ignored */
+#endif
+			break;
 		default: /* Unknown event */
 			pr_info("Unknown WMI event type 0x%x\n",
 				(int)buffer_entry[1]);