[PATCH v7 1/2] platform/x86: dell-privacy: Add support for Dell hardware privacy
Hans de Goede
hdegoede at redhat.com
Tue Apr 13 10:48:19 CEST 2021
Hi,
On 4/12/21 11:19 AM, Perry Yuan wrote:
> From: Perry Yuan <perry_yuan at dell.com>
>
> add support for Dell privacy driver for the Dell units equipped
> hardware privacy design, which protect users privacy of audio and
> camera from hardware level. Once the audio or camera privacy mode
> activated, any applications will not get any audio or video stream
> when user pressed ctrl+F4 hotkey, audio privacy mode will be
> enabled, micmute led will be also changed accordingly
> The micmute led is fully controlled by hardware & EC(embedded controller)
> and camera mute hotkey is Ctrl+F9. Currently design only emits
> SW_CAMERA_LENS_COVER event while the camera lens shutter will be
> changed by EC & HW(hardware) control
>
> *The flow is like this:
> 1) User presses key. HW does stuff with this key (timeout timer is started)
> 2) WMI event is emitted from BIOS to kernel
> 3) WMI event is received by dell-privacy
> 4) KEY_MICMUTE emitted from dell-privacy
> 5) Userland picks up key and modifies kcontrol for SW mute
> 6) Codec kernel driver catches and calls ledtrig_audio_set, like this:
> ledtrig_audio_set(LED_AUDIO_MICMUTE, rt715->micmute_led ? LED_ON :LED_OFF);
> 7) If "LED" is set to on dell-privacy notifies EC, and timeout is cancelled,
> HW mic mute activated. If EC not notified, HW mic mute will also be
> activated when timeout used up, it is just later than active ack
>
> Signed-off-by: Perry Yuan <perry_yuan at dell.com>
> ---
> 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 at dell.com>"
> +Description:
> + Display which dell hardware level privacy devices are supported
> + “Dell Privacy” is a set of HW, FW, and SW features to enhance
> + Dell’s commitment to platform privacy for MIC, Camera, and
> + ePrivacy screens.
> + The supported hardware privacy devices are:
> +Attributes:
> + Microphone Mute:
> + Identifies the local microphone can be muted by hardware, no applications
> + is available to capture system mic sound
> +
> + Camera Shutter:
> + Identifies camera shutter controlled by hardware, which is a micromechanical
> + shutter assembly that is built onto the camera module to block capturing images
> + from outside the laptop
> +
> + supported:
> + The privacy device is supported by this system
> +
> + unsupported:
> + The privacy device is not supported on this system
> +
> + For example to check which privacy devices are supported:
> +
> + # cat /sys/bus/wmi/drivers/dell-privacy/6932965F-1671-4CEB-B988-D3AB0A901919/dell_privacy_supported_type
> + [Microphone Mute] [supported]
> + [Camera Shutter] [supported]
> + [ePrivacy Screen] [unsupported]
> +
> +What: /sys/bus/wmi/devices/6932965F-1671-4CEB-B988-D3AB0A901919/dell_privacy_current_state
> +Date: Apr 2021
> +KernelVersion: 5.13
> +Contact: "perry.yuan at dell.com>"
> +Description:
> + Allow user space to check current dell privacy device state.
> + Describes the Device State class exposed by BIOS which can be
> + consumed by various applications interested in knowing the Privacy
> + feature capabilities
> +Attributes:
> + muted:
> + Identifies the privacy device is turned off and cannot send stream to OS applications
> +
> + unmuted:
> + Identifies the privacy device is turned on ,audio or camera driver can get
> + stream from mic and camera module to OS applications
> +
> + For example to check all supported current privacy device states:
> +
> + # cat /sys/bus/wmi/drivers/dell-privacy/6932965F-1671-4CEB-B988-D3AB0A901919/dell_privacy_current_state
> + [Microphone] [unmuted]
> + [Camera Shutter] [unmuted]
> diff --git a/drivers/platform/x86/dell/Kconfig b/drivers/platform/x86/dell/Kconfig
> index e0a55337f51a..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
> + 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 at dell.com>");
> +MODULE_DESCRIPTION("Dell Privacy WMI Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/platform/x86/dell/dell-privacy-wmi.h b/drivers/platform/x86/dell/dell-privacy-wmi.h
> new file mode 100644
> index 000000000000..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 at redhat.com>");
> MODULE_AUTHOR("Pali Rohár <pali at kernel.org>");
> @@ -427,7 +428,6 @@ static void dell_wmi_notify(struct wmi_device *wdev,
>
> switch (buffer_entry[1]) {
> case 0x0000: /* One key pressed or event occurred */
> - case 0x0012: /* Event with extended data occurred */
> if (len > 2)
> dell_wmi_process_key(wdev, buffer_entry[1],
> buffer_entry[2]);
> @@ -439,6 +439,12 @@ 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
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