linux-kernel - Re: [PATCH v5] platform/x86: lenovo-wmi-camera: Use SW_CAMERA_LENS_COVER instead of KEY_CAMERA

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Message-ID: <18ceac4e-f000-fe4c-4a81-25a6dc03a072@linux.intel.com>
Date: Tue, 7 Jan 2025 20:09:06 +0200 (EET)
From: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
To: Ai Chao <aichao@...inos.cn>
cc: Hans de Goede <hdegoede@...hat.com>, platform-driver-x86@...r.kernel.org, 
    LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v5] platform/x86: lenovo-wmi-camera: Use SW_CAMERA_LENS_COVER
 instead of KEY_CAMERA_ACESS

On Wed, 1 Jan 2025, Ai Chao wrote:

> 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 v5
> -Add input_report_switch before input_register_device.
> change for v4
> -Add mutex_unlock and report a switch state of 0 if SW_CAMERA_ON.
> 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 | 67 ++++++++++++++++--------
>  1 file changed, 44 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/platform/x86/lenovo-wmi-camera.c b/drivers/platform/x86/lenovo-wmi-camera.c
> index 0c0bedaf7407..ceed441a0161 100644
> --- a/drivers/platform/x86/lenovo-wmi-camera.c
> +++ b/drivers/platform/x86/lenovo-wmi-camera.c
> @@ -26,10 +26,38 @@ enum {
>  	SW_CAMERA_ON	= 1,
>  };
>  
> +static int camera_shutter_input_setup(struct wmi_device *wdev, u8 camera_mode)
> +{
> +	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);
> +
> +	input_report_switch(priv->idev, SW_CAMERA_LENS_COVER,
> +			    camera_mode == SW_CAMERA_ON ? 0 : 1);
> +	input_sync(priv->idev);
> +
> +	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 +83,18 @@ 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, camera_mode))
> +			dev_warn(&wdev->dev, "Failed to register input device\n");
> +
> +		mutex_unlock(&priv->notify_lock);
> +		return;
> +	}
> +
> +	if (camera_mode == SW_CAMERA_ON)
> +		input_report_switch(priv->idev, SW_CAMERA_LENS_COVER, 0);
> +	else
> +		input_report_switch(priv->idev, SW_CAMERA_LENS_COVER, 1);
>  	input_sync(priv->idev);
>  
>  	mutex_unlock(&priv->notify_lock);

Please just convert the mutex_lock() to use guard() and remove both 
mutex_unlock()s as cleanup.h will then handle that automatically for you.

-- 
 i.

> @@ -68,29 +103,12 @@ 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 +118,9 @@ 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);
>  }
>  
>