linux-kernel - Re: [PATCH v3] platform/x86: lenovo-wmi-camera: Use SW_CAMERA_LENS_COVER instead of KEY_CAMERA

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Message-ID: <d8f3bb68-8c08-45d6-9e34-760e869e05de@gmx.de>
Date: Mon, 30 Dec 2024 15:59:01 +0100
From: Armin Wolf <W_Armin@....de>
To: Ai Chao <aichao@...inos.cn>, hdegoede@...hat.com,
 ilpo.jarvinen@...ux.intel.com, platform-driver-x86@...r.kernel.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] platform/x86: lenovo-wmi-camera: Use
 SW_CAMERA_LENS_COVER instead of KEY_CAMERA_ACESS

Am 30.12.24 um 06:57 schrieb Ai Chao:

> Use SW_CAMERA_LENS_COVER instead of KEY_CAMERA_ACESS_ENABLE and
> KEY_CAMERA_ACESS_DISABLE. When the camera toggle switch was hit,
> the lenovo-wmi-camera driver would report an event code.
>
> Signed-off-by: Ai Chao <aichao@...inos.cn>
> ---
> change for v3
> -Used input_register_device and input_allocate_device.
> change for v2
> -Only delays the input-device registration and switches to reporting SW_CAMERA_LENS_COVER.
>
>   drivers/platform/x86/lenovo-wmi-camera.c | 59 +++++++++++++++---------
>   1 file changed, 36 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/platform/x86/lenovo-wmi-camera.c b/drivers/platform/x86/lenovo-wmi-camera.c
> index 0c0bedaf7407..e08960fabf9e 100644
> --- a/drivers/platform/x86/lenovo-wmi-camera.c
> +++ b/drivers/platform/x86/lenovo-wmi-camera.c
> @@ -26,10 +26,34 @@ enum {
>   	SW_CAMERA_ON	= 1,
>   };
>
> +static int camera_shutter_input_setup(struct wmi_device *wdev)
> +{
> +	struct lenovo_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
> +	int err;
> +
> +	priv->idev = input_allocate_device();
> +	if (!priv->idev)
> +		return -ENOMEM;
> +
> +	priv->idev->name = "Lenovo WMI Camera Button";
> +	priv->idev->phys = "wmi/input0";
> +	priv->idev->id.bustype = BUS_HOST;
> +	priv->idev->dev.parent = &wdev->dev;
> +
> +	input_set_capability(priv->idev, EV_SW, SW_CAMERA_LENS_COVER);
> +
> +	err = input_register_device(priv->idev);
> +	if (err) {
> +		input_free_device(priv->idev);
> +		priv->idev = NULL;
> +	}
> +
> +	return err;
> +}
> +
>   static void lenovo_wmi_notify(struct wmi_device *wdev, union acpi_object *obj)
>   {
>   	struct lenovo_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
> -	unsigned int keycode;
>   	u8 camera_mode;
>
>   	if (obj->type != ACPI_TYPE_BUFFER) {
> @@ -55,11 +79,14 @@ static void lenovo_wmi_notify(struct wmi_device *wdev, union acpi_object *obj)
>
>   	mutex_lock(&priv->notify_lock);
>
> -	keycode = camera_mode == SW_CAMERA_ON ?
> -		   KEY_CAMERA_ACCESS_ENABLE : KEY_CAMERA_ACCESS_DISABLE;
> -	input_report_key(priv->idev, keycode, 1);
> -	input_sync(priv->idev);
> -	input_report_key(priv->idev, keycode, 0);
> +	if (!priv->idev)
> +		if (camera_shutter_input_setup(wdev))
> +			return;

You need to call mutex_unlock() here before returning.

> +
> +	if (camera_mode == SW_CAMERA_ON)
> +		input_report_switch(priv->idev, SW_CAMERA_LENS_COVER, 1);
> +	else
> +		input_report_switch(priv->idev, SW_CAMERA_LENS_COVER, 0);
>   	input_sync(priv->idev);

The documentation for SW_CAMERA_LENS_COVER says:

	"set = lens covered" Since i assume SW_CAMMERA_ON means that the camera
is enabled i suggest that you report a switch state of 0 if camera_mode
is equal to SW_CAMERA_ON. Thanks, Armin Wolf

>
>   	mutex_unlock(&priv->notify_lock);
> @@ -68,29 +95,12 @@ static void lenovo_wmi_notify(struct wmi_device *wdev, union acpi_object *obj)
>   static int lenovo_wmi_probe(struct wmi_device *wdev, const void *context)
>   {
>   	struct lenovo_wmi_priv *priv;
> -	int ret;
>
>   	priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
>   	if (!priv)
>   		return -ENOMEM;
>
>   	dev_set_drvdata(&wdev->dev, priv);
> -
> -	priv->idev = devm_input_allocate_device(&wdev->dev);
> -	if (!priv->idev)
> -		return -ENOMEM;
> -
> -	priv->idev->name = "Lenovo WMI Camera Button";
> -	priv->idev->phys = "wmi/input0";
> -	priv->idev->id.bustype = BUS_HOST;
> -	priv->idev->dev.parent = &wdev->dev;
> -	input_set_capability(priv->idev, EV_KEY, KEY_CAMERA_ACCESS_ENABLE);
> -	input_set_capability(priv->idev, EV_KEY, KEY_CAMERA_ACCESS_DISABLE);
> -
> -	ret = input_register_device(priv->idev);
> -	if (ret)
> -		return ret;
> -
>   	mutex_init(&priv->notify_lock);
>
>   	return 0;
> @@ -100,6 +110,9 @@ static void lenovo_wmi_remove(struct wmi_device *wdev)
>   {
>   	struct lenovo_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
>
> +	if (priv->idev)
> +		input_unregister_device(priv->idev);
> +
>   	mutex_destroy(&priv->notify_lock);
>   }
>