Re: [PATCH v2] platform/x86: lenovo-super-hotkey-wmi.c: Support formic and audio mute LEDs

[Jackie Dong <xy-jackie@139.com>]

On 1/26/25 23:03, Armin Wolf wrote:
> Am 22.01.25 um 10:09 schrieb Jackie Dong:
> 
>> Implement Lenovo utility data WMI calls needed to make LEDs
>> work on Ideapads that support this GUID.
>> This enables the mic and audio LEDs to be updated correctly.
>>
>> Tested on below samples.
>> ThinkBook 13X Gen4 IMH
>> ThinkBook 14 G6 ABP
>> ThinkBook 16p Gen4-21J8
>> ThinkBook 16p Gen8-IRL
>> ThinkBook 16p G7+ ASP
>>
>> Signed-off-by: Jackie Dong <xy-jackie@139.com>
>> Suggested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
>> ---
>> Changes in v2:
>>   - Update code layout and formatting as recommended in review
>>   - Improved error handling in ideapad_wmi_led_init
>>   - Separated a WMI driver named lenovo-super-hotkey-wmi.c from
>>     ideapad-lap.c, it's only for Lenovo Super Hotkey WMI devices.
>>
>>   drivers/platform/x86/Kconfig                  |   7 +
>>   drivers/platform/x86/Makefile                 |   1 +
>>   .../platform/x86/lenovo-super-hotkey-wmi.c    | 236 ++++++++++++++++++
>>   3 files changed, 244 insertions(+)
>>   create mode 100644 drivers/platform/x86/lenovo-super-hotkey-wmi.c
>>
>> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
>> index 0258dd879d64..bd85ed58104b 100644
>> --- a/drivers/platform/x86/Kconfig
>> +++ b/drivers/platform/x86/Kconfig
>> @@ -475,6 +475,15 @@ config IDEAPAD_LAPTOP
>>         This is a driver for Lenovo IdeaPad netbooks contains drivers for
>>         rfkill switch, hotkey, fan control and backlight control.
>>
>> +config LENOVO_HOTKEY_WMI
>> +    tristate "Lenovo Super Hotkey Utility WMI extras driver"
>> +    depends on ACPI_WMI
>> +    depends on IDEAPAD_LAPTOP
>> +    help
>> +      This driver provides WMI support for Lenovo customized hotkeys 
>> function
>> +      of Lenovo NoteBooks which are for Consumer and SMB customers, 
>> such as
>> +      Ideapad/YOGA/XiaoXin/Gaming/ThinkBook and so on.
> 
> Please change the name of the Kconfig entry to LENOVO_SUPER_HOTKEY_WMI 
> to match the
> name of the driver.
> 
> Also, why does this driver depend on IDEAPAD_LAPTOP?
Hi Armin,
    Thanks for your carefully review and detail comments.
    I have updated the patch based on these comments and send it as v3 
just now.
    For depend on IDEAPAD_LAPTOP, because KEY_MICMUTE event is handled in
    ideapad_laptop. And this file only turn on/off MIC mute LED after 
the KEY_MICMUTE pressed. mic-mute LED function doesn't work without 
ideapad_laptop.ko.

{ KE_KEY,       0x3e | IDEAPAD_WMI_KEY, { KEY_MICMUTE } }, in 
ideapad_keymap[].

   As I said in Changes in v2, in fact, this file is separated a WMI 
driver named lenovo-super-hotkey-wmi.c from ideapad-lap.c.
   Pls review it again, thanks a lot!

> 
>> +
>>   config LENOVO_YMC
>>       tristate "Lenovo Yoga Tablet Mode Control"
>>       depends on ACPI_WMI
>> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/ 
>> Makefile
>> index e1b142947067..2d172128a6e4 100644
>> --- a/drivers/platform/x86/Makefile
>> +++ b/drivers/platform/x86/Makefile
>> @@ -61,6 +61,7 @@ obj-$(CONFIG_UV_SYSFS)       += uv_sysfs.o
>>   # IBM Thinkpad and Lenovo
>>   obj-$(CONFIG_IBM_RTL)        += ibm_rtl.o
>>   obj-$(CONFIG_IDEAPAD_LAPTOP)    += ideapad-laptop.o
>> +obj-$(CONFIG_LENOVO_HOTKEY_WMI)    += lenovo-super-hotkey-wmi.o
>>   obj-$(CONFIG_LENOVO_YMC)    += lenovo-ymc.o
>>   obj-$(CONFIG_SENSORS_HDAPS)    += hdaps.o
>>   obj-$(CONFIG_THINKPAD_ACPI)    += thinkpad_acpi.o
>> diff --git a/drivers/platform/x86/lenovo-super-hotkey-wmi.c b/drivers/ 
>> platform/x86/lenovo-super-hotkey-wmi.c
>> new file mode 100644
>> index 000000000000..d1611f935e30
>> --- /dev/null
>> +++ b/drivers/platform/x86/lenovo-super-hotkey-wmi.c
>> @@ -0,0 +1,236 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + *  Lenovo Super Hotkey Utility WMI extras driver for Ideapad laptop
>> + *
>> + *  Copyright (C) 2025    Lenovo
>> + */
>> +
>> +#include <linux/leds.h>
>> +#include <linux/wmi.h>
>> +#include "ideapad-laptop.h"
>> +
>> +/* Lenovo Super Hotkey WMI GUIDs */
>> +#define LUD_WMI_METHOD_GUID    "CE6C0974-0407-4F50-88BA-4FC3B6559AD8"
>> +#define LUPKE_WMI_EVENT_GUID    "8FC0DE0C-B4E4-43FD-B0F3-8871711C1294"
>> +
>> +/* Lenovo Utility Data WMI method_id */
>> +#define WMI_LUD_GET_SUPPORT 1
>> +#define WMI_LUD_SET_FEATURE 2
>> +
>> +#define WMI_LUD_GET_MICMUTE_LED_VER   20
>> +#define WMI_LUD_GET_AUDIOMUTE_LED_VER 26
>> +
>> +#define WMI_LUD_SUPPORT_MICMUTE_LED_VER   25
>> +#define WMI_LUD_SUPPORT_AUDIOMUTE_LED_VER 27
>> +
>> +/* Input parameters to mute/unmute audio LED and Mic LED */
>> +struct wmi_led_args {
>> +    u8 id;
>> +    u8 subid;
>> +    u16 value;
>> +};
>> +
>> +/* Values of input parameters to SetFeature of audio LED and Mic LED */
>> +enum hotkey_set_feature {
>> +    MIC_MUTE_LED_ON = 1,
>> +    MIC_MUTE_LED_OFF,
>> +    AUDIO_MUTE_LED_ON = 4,
>> +    AUDIO_MUTE_LED_OFF,
>> +};
>> +
>> +#define IDEAPAD_ACPI_LED_MAX 2
>> +
>> +enum ideapad_wmi_event_type {
>> +    IDEAPAD_WMI_EVENT_FN_KEYS = 1,
>> +    IDEAPAD_WMI_EVENT_LUD_KEYS,
>> +};
>> +
>> +struct ideapad_wmi_private {
> 
> Please rename everything in this driver which contains the name "ideapad"
> to instead contain the name of this driver.
> 
>> +    enum ideapad_wmi_event_type event;
>> +    struct led_classdev cdev[IDEAPAD_ACPI_LED_MAX];
>> +};
>> +
>> +static struct wmi_device *led_wdev;
> 
> Please use container_of() to get a reference to your private data struct.
> 
> Toachieve that i suggest you rework your private data struct like this:
> struct lenovo_hotkey_private { enum mute_led_type type; struct
> wmi_device *wdev; struct led_classdev cdev; }; You can then allocate a
> private data struct for each LED device and use container_of(led_cdev, 
> struct lenovo_hotkey_private, cdev) to get a reference to the
> associated struct from each LED classdev pointer. Then you can access
> the WMI device and the LED type without having to use global variables.
> 
>> +
>> +enum mute_led_type {
>> +    MIC_MUTE,
>> +    AUDIO_MUTE,
>> +};
>> +
>> +static int ideapad_wmi_mute_led_set(enum mute_led_type led_type, 
>> struct led_classdev *led_cdev,
>> +                    enum led_brightness brightness)
>> +
>> +{
>> +    struct wmi_led_args led_arg = {0, 0, 0};
>> +    struct acpi_buffer input;
>> +    acpi_status status;
>> +
>> +    switch (led_type) {
>> +    case MIC_MUTE:
>> +        led_arg.id = brightness == LED_ON ? MIC_MUTE_LED_ON : 
>> MIC_MUTE_LED_OFF;
>> +        break;
>> +    case AUDIO_MUTE:
>> +        led_arg.id = brightness == LED_ON ? AUDIO_MUTE_LED_ON : 
>> AUDIO_MUTE_LED_OFF;
>> +        break;
>> +    default:
>> +        return -EINVAL;
>> +    }
>> +
>> +    input.length = sizeof(struct wmi_led_args);
> 
> sizeof(struct wmi_led_args) -> sizeof(led_arg)
> 
>> +    input.pointer = &led_arg;
>> +    status = wmidev_evaluate_method(led_wdev, 0, WMI_LUD_SET_FEATURE, 
>> &input, NULL);
>> +    if (ACPI_FAILURE(status))
>> +        return -EIO;
>> +
>> +    return 0;
>> +}
>> +
>> +static int ideapad_wmi_audiomute_led_set(struct led_classdev *led_cdev,
>> +                     enum led_brightness brightness)
>> +
>> +{
>> +    return ideapad_wmi_mute_led_set(AUDIO_MUTE, led_cdev, brightness);
>> +}
>> +
>> +static int ideapad_wmi_micmute_led_set(struct led_classdev *led_cdev,
>> +                       enum led_brightness brightness)
>> +{
>> +    return ideapad_wmi_mute_led_set(MIC_MUTE, led_cdev, brightness);
>> +}
>> +
>> +static int ideapad_wmi_led_init(enum mute_led_type led_type, struct 
>> device *dev)
>> +{
>> +    struct ideapad_wmi_private *wpriv = dev_get_drvdata(dev);
>> +    struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
>> +    struct acpi_buffer input;
>> +    union acpi_object *obj;
>> +    int led_version, err = 0;
>> +    unsigned int wmiarg;
>> +    acpi_status status;
>> +
>> +    switch (led_type) {
>> +    case MIC_MUTE:
>> +        wmiarg = WMI_LUD_GET_MICMUTE_LED_VER;
>> +        break;
>> +    case AUDIO_MUTE:
>> +        wmiarg = WMI_LUD_GET_AUDIOMUTE_LED_VER;
>> +        break;
>> +    default:
>> +        return -EINVAL;
>> +    }
>> +
>> +    input.length = sizeof(wmiarg);
>> +    input.pointer = &wmiarg;
>> +    status = wmidev_evaluate_method(led_wdev, 0, WMI_LUD_GET_SUPPORT, 
>> &input, &output);
>> +    if (ACPI_FAILURE(status))
>> +        return -EIO;
>> +
>> +    obj = output.pointer;
>> +    led_version = obj->integer.value;
> 
> Please check if the resulting ACPI object is:
> 
> - not NULL
> - actually an integer
> 
> I also suggest that you copy the integer inside a local variable and 
> free the ACPI object
> as soon as possible to avoid leaking it later.
> 
>> +
>> +    wpriv->cdev[led_type].max_brightness = LED_ON;
>> +    wpriv->cdev[led_type].dev = dev;
>> +    wpriv->cdev[led_type].flags = LED_CORE_SUSPENDRESUME;
>> +
>> +    switch (led_type) {
>> +    case MIC_MUTE:
>> +        if (led_version != WMI_LUD_SUPPORT_MICMUTE_LED_VER) {
>> +            err = -EIO;
>> +            goto led_error;
>> +        }
>> +        wpriv->cdev[led_type].name = "platform::micmute";
>> +        wpriv->cdev[led_type].brightness_set_blocking = 
>> &ideapad_wmi_micmute_led_set;
>> +        wpriv->cdev[led_type].default_trigger = "audio-micmute";
>> +
>> +        err = devm_led_classdev_register(dev, &wpriv->cdev[led_type]);
>> +        if (err < 0)
>> +            goto led_reg_failed;
>> +
>> +        break;
>> +    case AUDIO_MUTE:
>> +        if (led_version != WMI_LUD_SUPPORT_AUDIOMUTE_LED_VER) {
>> +            err = -EIO;
>> +            goto led_error;
>> +        }
>> +        wpriv->cdev[led_type].name = "platform::mute";
>> +        wpriv->cdev[led_type].brightness_set_blocking = 
>> &ideapad_wmi_audiomute_led_set;
>> +        wpriv->cdev[led_type].default_trigger = "audio-mute";
>> +
>> +        err = devm_led_classdev_register(dev, &wpriv->cdev[led_type]);
>> +        if (err < 0)
>> +            goto led_reg_failed;
>> +
>> +        break;
>> +    default:
>> +        err = -EINVAL;
>> +        dev_err(dev, "Unknown LED type %d\n", led_type);
>> +        goto led_error;
>> +    }
>> +
>> +    kfree(obj);
>> +    return 0;
>> +
>> +led_reg_failed:
>> +    dev_err(dev, "Could not register mute LED %d : %d\n", led_type, 
>> err);
>> +    led_classdev_unregister(&wpriv->cdev[led_type]);
> 
> Do not call led_classdev_unregister() here if the LED device could not 
> be registered in the first place.
> 
>> +led_error:
>> +    kfree(obj);
>> +    return err;
>> +}
>> +
>> +static void ideapad_wmi_leds_setup(struct device *dev)
>> +{
>> +    ideapad_wmi_led_init(MIC_MUTE, dev);
>> +    ideapad_wmi_led_init(AUDIO_MUTE, dev);
>> +}
>> +
>> +static int lenovo_super_hotkey_wmi_probe(struct wmi_device *wdev, 
>> const void *context)
>> +{
>> +    struct ideapad_wmi_private *wpriv;
>> +
>> +    wpriv = devm_kzalloc(&wdev->dev, sizeof(*wpriv), GFP_KERNEL);
>> +    if (!wpriv)
>> +        return -ENOMEM;
>> +
>> +    *wpriv = *(const struct ideapad_wmi_private *)context;
>> +
>> +    dev_set_drvdata(&wdev->dev, wpriv);
>> +
>> +    if (wpriv->event == IDEAPAD_WMI_EVENT_LUD_KEYS) {
>> +        led_wdev = wdev;
>> +        ideapad_wmi_leds_setup(&wdev->dev);
>> +    }
> 
> What is the purpose of IDEAPAD_WMI_EVENT_FN_KEYS?
> 
> Please remove the whole IDEAPAD_WMI_EVENT_FN_KEYS/ 
> IDEAPAD_WMI_EVENT_LUD_KEYS
> context handling code and instead only handle the LUD_WMI_METHOD_GUID in
> this driver.
> 
>> +
>> +    return 0;
>> +}
>> +
>> +static const struct ideapad_wmi_private lsk_wmi_context_fn_keys = {
>> +    .event = IDEAPAD_WMI_EVENT_FN_KEYS
>> +};
>> +
>> +static const struct ideapad_wmi_private lsk_wmi_context_lud_keys = {
>> +    .event = IDEAPAD_WMI_EVENT_LUD_KEYS
>> +};
>> +
>> +static const struct wmi_device_id lenovo_super_hotkey_wmi_id_table[] = {
>> +    { LUPKE_WMI_EVENT_GUID, &lsk_wmi_context_fn_keys }, /* FN keys */
>> +    { LUD_WMI_METHOD_GUID, &lsk_wmi_context_lud_keys }, /* Utility 
>> data */
>> +    { }
> 
> What is the reason for trying to bind to the LUPKE_WMI_EVENT_GUID?
> 
> AFAIK the ideapad-laptop driver already takes care of that.
> 
>> +};
>> +
>> +MODULE_DEVICE_TABLE(wmi, lenovo_super_hotkey_wmi_id_table);
>> +
>> +static struct wmi_driver lenovo_super_hotkey_wmi_driver = {
>> +     .driver = {
>> +         .name = "lenovo_super_hotkey_wmi",
> 
> Please set .probe_type = PROBE_PREFER_ASYNCHRONOUS
> 
>> +     },
>> +     .id_table = lenovo_super_hotkey_wmi_id_table,
>> +     .probe = lenovo_super_hotkey_wmi_probe,
> 
> Please set .no_singleton = true
> 
> Thanks,
> Armin Wolf
> 
>> +};
>> +
>> +module_wmi_driver(lenovo_super_hotkey_wmi_driver);
>> +
>> +MODULE_INFO(depends, "wmi,ideapad-laptop");
>> +MODULE_AUTHOR("Jackie Dong <dongeg1@lenovo.com>");
>> +MODULE_DESCRIPTION("Lenovo Super Hotkey Utility WMI extras driver");
>> +MODULE_LICENSE("GPL");