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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/platform/x86/dell/dell-wmi-privacy.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/platform/x86/dell/dell-wmi-privacy.c')
-rw-r--r-- | drivers/platform/x86/dell/dell-wmi-privacy.c | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/drivers/platform/x86/dell/dell-wmi-privacy.c b/drivers/platform/x86/dell/dell-wmi-privacy.c new file mode 100644 index 000000000..c517bd45d --- /dev/null +++ b/drivers/platform/x86/dell/dell-wmi-privacy.c @@ -0,0 +1,406 @@ +// 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-wmi-privacy.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_VSW, 0x0002, { SW_CAMERA_LENS_COVER } }, + { KE_END, 0}, +}; + +bool dell_privacy_has_mic_mute(void) +{ + struct privacy_wmi_data *priv; + + mutex_lock(&list_mutex); + priv = list_first_entry_or_null(&wmi_list, + struct privacy_wmi_data, + list); + mutex_unlock(&list_mutex); + + return priv && (priv->features_present & BIT(DELL_PRIVACY_TYPE_AUDIO)); +} +EXPORT_SYMBOL_GPL(dell_privacy_has_mic_mute); + +/* + * 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 which will call + * led_set_brightness() on the LED registered by dell_privacy_leds_setup() + * 7) dell-privacy notifies EC, the timeout is cancelled and the HW mute activates. + * If the EC is not notified then the HW mic mute will activate when the timeout + * triggers, just a bit later than with the active ack. + */ +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 */ + priv->last_status = status; + sparse_keymap_report_entry(priv->input_dev, key, 1, true); + ret = true; + break; + case DELL_PRIVACY_CAMERA_EVENT: /* Camera mute */ + priv->last_status = status; + sparse_keymap_report_entry(priv->input_dev, key, !(status & CAMERA_STATUS), false); + 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; +} + +static ssize_t dell_privacy_supported_type_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct privacy_wmi_data *priv = dev_get_drvdata(dev); + enum dell_hardware_privacy_type type; + u32 privacy_list; + int len = 0; + + privacy_list = priv->features_present; + for (type = DELL_PRIVACY_TYPE_AUDIO; type < DELL_PRIVACY_TYPE_MAX; type++) { + if (privacy_list & BIT(type)) + len += sysfs_emit_at(buf, len, "[%s] [supported]\n", privacy_types[type]); + else + len += sysfs_emit_at(buf, len, "[%s] [unsupported]\n", privacy_types[type]); + } + + return len; +} + +static ssize_t dell_privacy_current_state_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct privacy_wmi_data *priv = dev_get_drvdata(dev); + u32 privacy_supported = priv->features_present; + enum dell_hardware_privacy_type type; + u32 privacy_state = priv->last_status; + int len = 0; + + for (type = DELL_PRIVACY_TYPE_AUDIO; type < DELL_PRIVACY_TYPE_MAX; type++) { + if (privacy_supported & BIT(type)) { + if (privacy_state & BIT(type)) + len += sysfs_emit_at(buf, len, "[%s] [unmuted]\n", privacy_types[type]); + else + len += sysfs_emit_at(buf, len, "[%s] [muted]\n", privacy_types[type]); + } + } + + return len; +} + +static DEVICE_ATTR_RO(dell_privacy_supported_type); +static DEVICE_ATTR_RO(dell_privacy_current_state); + +static struct attribute *privacy_attrs[] = { + &dev_attr_dell_privacy_supported_type.attr, + &dev_attr_dell_privacy_current_state.attr, + NULL, +}; +ATTRIBUTE_GROUPS(privacy); + +/* + * 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, j; + + 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; + + ret = get_current_status(priv->wdev); + if (ret) + return ret; + + /* 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, j = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0012); i++) { + /* + * Unlike keys where only presses matter, userspace may act + * on switches in both of their positions. Only register + * SW_CAMERA_LENS_COVER if it is actually there. + */ + if (dell_wmi_keymap_type_0012[i].type == KE_VSW && + dell_wmi_keymap_type_0012[i].sw.code == SW_CAMERA_LENS_COVER && + !(priv->features_present & BIT(DELL_PRIVACY_TYPE_CAMERA))) + continue; + + keymap[j] = dell_wmi_keymap_type_0012[i]; + keymap[j].code |= (0x0012 << 16); + j++; + } + 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; + + /* Report initial camera-cover status */ + if (priv->features_present & BIT(DELL_PRIVACY_TYPE_CAMERA)) + input_report_switch(priv->input_dev, SW_CAMERA_LENS_COVER, + !(priv->last_status & CAMERA_STATUS)); + + ret = input_register_device(priv->input_dev); + if (ret) + return ret; + + if (priv->features_present & BIT(DELL_PRIVACY_TYPE_AUDIO)) { + ret = dell_privacy_leds_setup(&priv->wdev->dev); + if (ret) + return ret; + } + mutex_lock(&list_mutex); + list_add_tail(&priv->list, &wmi_list); + mutex_unlock(&list_mutex); + return 0; +} + +static void 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); +} + +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", + .dev_groups = privacy_groups, + }, + .probe = dell_privacy_wmi_probe, + .remove = dell_privacy_wmi_remove, + .id_table = dell_wmi_privacy_wmi_id_table, +}; + +int dell_privacy_register_driver(void) +{ + return wmi_driver_register(&dell_privacy_wmi_driver); +} + +void dell_privacy_unregister_driver(void) +{ + wmi_driver_unregister(&dell_privacy_wmi_driver); +} |