Re: [PATCH v4 04/14] platform/x86: alienware-wmi: Refactor LED control methods

[Armin Wolf <W_Armin@gmx.de>]

Am 17.01.25 um 09:13 schrieb Kurt Borja:

> Both WMI devices handled by this module specify a distinct interface for
> LED control. Previously this module handled this by dynamically adapting
> arguments passed to wmi_evaluate_method() based on the `interface`
> global variable.
>
> To avoid the use of global variables, and enable the migration to
> non-deprecated WMI methods, let the WMI drivers define upd_led and
> upd_brightness operations, which completely replace
> alienware_update_led() and wmax_brightness().
>
> Also define alienware_wmi_command(), which serves as a wrapper for
> wmidev_evaluate_method(). This new method is very similar to
> alienware_wmax_command() but is WMI device agnostic.
>
> Signed-off-by: Kurt Borja <kuurtb@gmail.com>
> ---
>   drivers/platform/x86/dell/alienware-wmi.c | 164 ++++++++++++++--------
>   1 file changed, 102 insertions(+), 62 deletions(-)
>
> diff --git a/drivers/platform/x86/dell/alienware-wmi.c b/drivers/platform/x86/dell/alienware-wmi.c
> index 7356260f7f09..c9d9cf36b87b 100644
> --- a/drivers/platform/x86/dell/alienware-wmi.c
> +++ b/drivers/platform/x86/dell/alienware-wmi.c
> @@ -417,12 +417,42 @@ struct alienfx_priv {
>   	u8 lighting_control_state;
>   };
>
> +struct alienfx_ops {
> +	int (*upd_led)(struct alienfx_priv *priv, struct wmi_device *wdev,
> +		       u8 location);
> +	int (*upd_brightness)(struct alienfx_priv *priv, struct wmi_device *wdev,
> +			      u8 brightness);
> +};
> +
>   struct alienfx_platdata {
>   	struct wmi_device *wdev;
> +	struct alienfx_ops ops;
>   };
>
>   static u8 interface;
>
> +static int alienware_wmi_command(struct wmi_device *wdev, u32 method_id,
> +				 void *in_args, size_t in_size, u32 *out_data)
> +{
> +	struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
> +	struct acpi_buffer in = {in_size, in_args};
> +	union acpi_object *obj;
> +	acpi_status ret;
> +
> +	ret = wmidev_evaluate_method(wdev, 0, method_id, &in, out_data ? &out : NULL);
> +	if (ACPI_FAILURE(ret))
> +		return -EIO;
> +
> +	obj = out.pointer;
> +
> +	if (out_data && obj && obj->type == ACPI_TYPE_INTEGER)
> +		*out_data = (u32)obj->integer.value;

Please return an error here if out_data is true but obj is NULL or not of ACPI_TYPE_INTEGER.

With this being fixed:

Reviewed-by: Armin Wolf <W_Armin@gmx.de>

> +
> +	kfree(obj);
> +
> +	return 0;
> +}
> +
>   /*
>    * Helpers used for zone control
>    */
> @@ -453,46 +483,6 @@ static int parse_rgb(const char *buf, struct color_platform *colors)
>   /*
>    * Individual RGB zone control
>    */
> -static int alienware_update_led(struct alienfx_priv *priv, u8 location)
> -{
> -	int method_id;
> -	acpi_status status;
> -	char *guid;
> -	struct acpi_buffer input;
> -	struct legacy_led_args legacy_args;
> -	struct wmax_led_args wmax_basic_args;
> -	if (interface == WMAX) {
> -		wmax_basic_args.led_mask = 1 << location;
> -		wmax_basic_args.colors = priv->colors[location];
> -		wmax_basic_args.state = priv->lighting_control_state;
> -		guid = WMAX_CONTROL_GUID;
> -		method_id = WMAX_METHOD_ZONE_CONTROL;
> -
> -		input.length = sizeof(wmax_basic_args);
> -		input.pointer = &wmax_basic_args;
> -	} else {
> -		legacy_args.colors = priv->colors[location];
> -		legacy_args.brightness = priv->global_brightness;
> -		legacy_args.state = 0;
> -		if (priv->lighting_control_state == LEGACY_BOOTING ||
> -		    priv->lighting_control_state == LEGACY_SUSPEND) {
> -			guid = LEGACY_POWER_CONTROL_GUID;
> -			legacy_args.state = priv->lighting_control_state;
> -		} else
> -			guid = LEGACY_CONTROL_GUID;
> -		method_id = location + 1;
> -
> -		input.length = sizeof(legacy_args);
> -		input.pointer = &legacy_args;
> -	}
> -	pr_debug("alienware-wmi: guid %s method %d\n", guid, method_id);
> -
> -	status = wmi_evaluate_method(guid, 0, method_id, &input, NULL);
> -	if (ACPI_FAILURE(status))
> -		pr_err("alienware-wmi: zone set failure: %u\n", status);
> -	return ACPI_FAILURE(status);
> -}
> -
>   static ssize_t zone_show(struct device *dev, struct device_attribute *attr,
>   			 char *buf, u8 location)
>   {
> @@ -509,13 +499,14 @@ static ssize_t zone_store(struct device *dev, struct device_attribute *attr,
>   {
>   	struct alienfx_priv *priv = dev_get_drvdata(dev);
>   	struct color_platform *colors = &priv->colors[location];
> +	struct alienfx_platdata *pdata = dev_get_platdata(dev);
>   	int ret;
>
>   	ret = parse_rgb(buf, colors);
>   	if (ret)
>   		return ret;
>
> -	ret = alienware_update_led(priv, location);
> +	ret = pdata->ops.upd_led(priv, pdata->wdev, location);
>
>   	return ret ? ret : count;
>   }
> @@ -651,36 +642,17 @@ static struct attribute_group zone_attribute_group = {
>   /*
>    * LED Brightness (Global)
>    */
> -static int wmax_brightness(int brightness)
> -{
> -	acpi_status status;
> -	struct acpi_buffer input;
> -	struct wmax_brightness_args args = {
> -		.led_mask = 0xFF,
> -		.percentage = brightness,
> -	};
> -	input.length = sizeof(args);
> -	input.pointer = &args;
> -	status = wmi_evaluate_method(WMAX_CONTROL_GUID, 0,
> -				     WMAX_METHOD_BRIGHTNESS, &input, NULL);
> -	if (ACPI_FAILURE(status))
> -		pr_err("alienware-wmi: brightness set failure: %u\n", status);
> -	return ACPI_FAILURE(status);
> -}
> -
>   static void global_led_set(struct led_classdev *led_cdev,
>   			   enum led_brightness brightness)
>   {
>   	struct alienfx_priv *priv = container_of(led_cdev, struct alienfx_priv,
>   						 global_led);
> +	struct alienfx_platdata *pdata = dev_get_platdata(&priv->pdev->dev);
>   	int ret;
>
>   	priv->global_brightness = brightness;
>
> -	if (interface == WMAX)
> -		ret = wmax_brightness(brightness);
> -	else
> -		ret = alienware_update_led(priv, 0);
> +	ret = pdata->ops.upd_brightness(priv, pdata->wdev, brightness);
>   	if (ret)
>   		pr_err("LED brightness update failed\n");
>   }
> @@ -1234,10 +1206,49 @@ static void alienware_alienfx_exit(struct wmi_device *wdev)
>   /*
>    * Legacy WMI driver
>    */
> +static int legacy_wmi_update_led(struct alienfx_priv *priv,
> +				 struct wmi_device *wdev, u8 location)
> +{
> +	struct legacy_led_args legacy_args = {
> +		.colors = priv->colors[location],
> +		.brightness = priv->global_brightness,
> +		.state = 0,
> +	};
> +	struct acpi_buffer input;
> +	acpi_status status;
> +
> +	if (legacy_args.state != LEGACY_RUNNING) {
> +		legacy_args.state = priv->lighting_control_state;
> +
> +		input.length = sizeof(legacy_args);
> +		input.pointer = &legacy_args;
> +
> +		status = wmi_evaluate_method(LEGACY_POWER_CONTROL_GUID, 0,
> +					     location + 1, &input, NULL);
> +		if (ACPI_FAILURE(status))
> +			return -EIO;
> +
> +		return 0;
> +	}
> +
> +	return alienware_wmi_command(wdev, location + 1, &legacy_args,
> +				     sizeof(legacy_args), NULL);
> +}
> +
> +static int legacy_wmi_update_brightness(struct alienfx_priv *priv,
> +					struct wmi_device *wdev, u8 brightness)
> +{
> +	return legacy_wmi_update_led(priv, wdev, 0);
> +}
> +
>   static int legacy_wmi_probe(struct wmi_device *wdev, const void *context)
>   {
>   	struct alienfx_platdata pdata = {
>   		.wdev = wdev,
> +		.ops = {
> +			.upd_led = legacy_wmi_update_led,
> +			.upd_brightness = legacy_wmi_update_brightness,
> +		},
>   	};
>
>   	return alienware_alienfx_setup(&pdata);
> @@ -1277,10 +1288,39 @@ static void __exit alienware_legacy_wmi_exit(void)
>   /*
>    * WMAX WMI driver
>    */
> +static int wmax_wmi_update_led(struct alienfx_priv *priv,
> +			       struct wmi_device *wdev, u8 location)
> +{
> +	struct wmax_led_args in_args = {
> +		.led_mask = 1 << location,
> +		.colors = priv->colors[location],
> +		.state = priv->lighting_control_state,
> +	};
> +
> +	return alienware_wmi_command(wdev, WMAX_METHOD_ZONE_CONTROL, &in_args,
> +				     sizeof(in_args), NULL);
> +}
> +
> +static int wmax_wmi_update_brightness(struct alienfx_priv *priv,
> +				      struct wmi_device *wdev, u8 brightness)
> +{
> +	struct wmax_brightness_args in_args = {
> +		.led_mask = 0xFF,
> +		.percentage = brightness,
> +	};
> +
> +	return alienware_wmi_command(wdev, WMAX_METHOD_BRIGHTNESS, &in_args,
> +				     sizeof(in_args), NULL);
> +}
> +
>   static int wmax_wmi_probe(struct wmi_device *wdev, const void *context)
>   {
>   	struct alienfx_platdata pdata = {
>   		.wdev = wdev,
> +		.ops = {
> +			.upd_led = wmax_wmi_update_led,
> +			.upd_brightness = wmax_wmi_update_brightness,
> +		},
>   	};
>   	struct platform_device *pdev;
>   	int ret;