Hi Hans.
I changed the driver in V8 as your comments.
Just one Kconfig change , It will cause some built error .
> -----Original Message-----
> From: Hans de Goede <hdegoede@xxxxxxxxxx>
> Sent: 2021年4月13日 16:48
> To: Yuan, Perry; pobrn@xxxxxxxxxxxxxx; pierre-
> louis.bossart@xxxxxxxxxxxxxxx; oder_chiou@xxxxxxxxxxx; perex@xxxxxxxx;
> tiwai@xxxxxxxx; mgross@xxxxxxxxxxxxxxx
> Cc: lgirdwood@xxxxxxxxx; broonie@xxxxxxxxxx; alsa-devel@xxxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; platform-driver-x86@xxxxxxxxxxxxxxx;
> mario.limonciello@xxxxxxxxxxx; Dell Client Kernel
> Subject: Re: [PATCH v7 1/2] platform/x86: dell-privacy: Add support for Dell
> hardware privacy
>
>
> [EXTERNAL EMAIL]
>
> Hi,
>
> On 4/12/21 11:19 AM, Perry Yuan wrote:
> > From: Perry Yuan <perry_yuan@xxxxxxxx>
> >
> > 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@xxxxxxxx>
> > ---
> > v5 -> v6:
> > * addressed feedback from Hans
> > * addressed feedback from Pierre
> > * optimize some debug format with dev_dbg()
> > * 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
>
> Thank you, almost there. A few small remarks inline.
>
> > 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 | 23 +-
> > drivers/platform/x86/dell/dell-privacy-wmi.c | 394
> > ++++++++++++++++++ drivers/platform/x86/dell/dell-privacy-wmi.h | 23 +
> > drivers/platform/x86/dell/dell-wmi.c | 8 +-
> > 7 files changed, 511 insertions(+), 7 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@xxxxxxxx>"
> > +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@xxxxxxxx>"
> > +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..05d124442b25 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
> > + select DELL_WMI
>
> DELL_WMI is not a helper library which can be selected, please use depends
> on here.
>
> More in general I'm a bit worried about the dependencies being added to dell-
> laptop.c and dell-wmi.c on the new dell-privacy-wmi.ko module.
>
> What if e.g. dell-laptop.c gets builtin while dell-privacy-wmi.c is a module.
>
> Then we have dell-laptop.c depending on the dell_privacy_present linker-
> symbol, but that symbol is in a module, so the main vmlinuz binary will fail to
> link due to that missing symbol.
>
> To fix this you need to add:
>
> depends on DELL_PRIVACY || DELL_PRIVACY = n
>
> To the Kconfig sections for both DELL_WMI and DELL_LAPTOP
If I add "depends on DELL_PRIVACY || DELL_PRIVACY = n" to both DELL_WMI and DELL_LAPTOP
The compile will report error "recursive dependency detected"
I do not think the dell-laptop will be builtin option as we know.
I am confused that why the symbol will be failed to link like that ?
because the compiler can find the dell_privacy_present which is defined in one common header file.
>
>
> > + 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..e7ffc0b81208 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 has_privacy;
>
> There is a problem in the del-laptop.c code with the led_classdev
> unregistering which is not introduced by this patch, but this patch is a good
> opportunity to fix this.
>
> The problem is that in the dell_init error-exit path as well as in dell_exit
> led_classdev_unregister() gets called unconditionally, while the registering
> has only happened under the following condition:
>
> if (dell_smbios_find_token(GLOBAL_MIC_MUTE_DISABLE) &&
> dell_smbios_find_token(GLOBAL_MIC_MUTE_ENABLE)) {
>
> So this means that the code may end up unregistering a never registered
> led_classdev which is not good.
>
> Since you are making the unregistering conditional in this patch, it would be
> good to also fix this issue.
>
> Please change:
>
> static bool has_privacy;
>
> To:
>
> static bool micmute_led_registered;
>
>
>
> >
> > module_param(force_rfkill, bool, 0444);
> > MODULE_PARM_DESC(force_rfkill, "enable rfkill on non whitelisted
> > models"); @@ -2206,10 +2209,16 @@ static int __init dell_init(void)
> >
> > 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;
> > + if (dell_privacy_present())
> > + has_privacy = true;
> > + else
> > + has_privacy = false;
> > + if (!has_privacy) {
> > + 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;
> > + }
> > }
>
> And change this block to
>
> if (dell_smbios_find_token(GLOBAL_MIC_MUTE_DISABLE) &&
> 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;
> }
>
> This also looks cleaner/nicer with one less indent level too :)
>
>
> >
> > 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 (!has_privacy)
>
> Change this to:
>
> if (micmute_led_registered)
> > + led_classdev_unregister(&micmute_led_cdev);
>
> This way the if condition also is more logical / easier to see why the if is there.
>
> > 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 (!has_privacy)
>
> And here too, change this to:
>
> 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..4be7548d1a03
> > --- /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;
> > +}
> > +EXPORT_SYMBOL_GPL(dell_privacy_present);
>
> I thought that we had chaned this to dell_privacy_has_mic_mute ?
>
> Returning:
>
> return priv && (priv->features_present &
> BIT(DELL_PRIVACY_TYPE_AUDIO));
>
> ?
>
> What has happened to that change, please change that back, the only user of
> dell_privacy_present() is dell-laptop.c and that wants to know if dell-privacy.c
> will be handling the mute-led or not, so only checking for dell-privacy
> presence is not enough.
>
>
>
> > +
> > +/*
> > + * 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;
> > + char *s = buf;
> > +
> > + privacy_list = priv->features_present;
> > + for (type = DELL_PRIVACY_TYPE_AUDIO; type <
> DELL_PRIVACY_TYPE_MAX; type++) {
> > + if (privacy_list & BIT(type))
> > + s += sprintf(s, "[%s] [supported]\n",
> privacy_types[type]);
> > + else
> > + s += sprintf(s, "[%s] [unsupported]\n",
> privacy_types[type]);
> > + }
> > +
> > + return (s - buf);
> > +}
>
> As mentioned before I think (not sure), please use sysfs_emit_at here, like this:
>
> 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;
> }
>
> This will ensure that we never overrun the size of the passed in buffer.
>
>
>
> > +
> > +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;
> > + char *s = buf;
> > +
> > + for (type = DELL_PRIVACY_TYPE_AUDIO; type <
> DELL_PRIVACY_TYPE_MAX; type++) {
> > + if (privacy_supported & BIT(type)) {
> > + if (privacy_state & BIT(type))
> > + s += sprintf(s, "[%s] [unmuted]\n",
> privacy_types[type]);
> > + else
> > + s += sprintf(s, "[%s] [muted]\n",
> privacy_types[type]);
> > + }
> > + }
> > +
> > + return (s - buf);
> > +}
>
> And the same here.
>
>
> > +
> > +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;
> > +
> > + ret = dell_privacy_leds_setup(&priv->wdev->dev);
> > + if (ret)
> > + return ret;
>
> This should be conditional on the audio privacy feature being supported:
>
> 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@xxxxxxxx>");
> > +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..04c49d2fa924
> > --- /dev/null
> > +++ b/drivers/platform/x86/dell/dell-privacy-wmi.h
> > @@ -0,0 +1,23 @@
> > +/* 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) {}
>
> This is missing a return false; between the {}.
>
> > +#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..228e85a427f5 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@xxxxxxxxxx>");
> > MODULE_AUTHOR("Pali Rohár <pali@xxxxxxxxxx>"); @@ -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 +439,12 @@ 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]))
> > + /* privacy hotkey handle */;
>
> Please change this comment to:
>
> /* 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]);
> >
>
>
>
> Regards,
>
> Hans
