Re: [RFC PATCH 3/3] platform/x86: uniwill-laptop: Offer support to activate local dimming

[Armin Wolf <W_Armin@gmx.de>]

Am 21.04.26 um 22:01 schrieb Werner Sembach:

> This patch adds a sysfs variable local_dimming to supported devices.
> Setting it to true enables local dimming for the internal notebook display.
>
> Currently only TUXEDO Stellaris 16 Gen7 Intel/AMD with mLED displays are
> supported.
>
> Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
> ---
>   drivers/platform/x86/uniwill/uniwill-acpi.c | 162 +++++++++++++++++++-
>   1 file changed, 158 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/platform/x86/uniwill/uniwill-acpi.c b/drivers/platform/x86/uniwill/uniwill-acpi.c
> index 62d56cc67e2e8..909d8608a2f80 100644
> --- a/drivers/platform/x86/uniwill/uniwill-acpi.c
> +++ b/drivers/platform/x86/uniwill/uniwill-acpi.c
> @@ -275,6 +275,9 @@
>   #define EC_ADDR_USB_C_POWER_PRIORITY	0x07CC
>   #define USB_C_POWER_PRIORITY		BIT(7)
>   
> +#define EC_ADDR_LOCAL_DIMMING_SUPPORT	0x0D4F
> +#define LOCAL_DIMMING_SUPPORT		BIT(0)
> +
>   /* Same bits as EC_ADDR_LIGHTBAR_AC_CTRL except LIGHTBAR_S3_OFF */
>   #define EC_ADDR_LIGHTBAR_BAT_CTRL	0x07E2
>   
> @@ -296,6 +299,14 @@
>   
>   #define EC_ADDR_GPU_FAN_SPEED_TABLE	0x0F50
>   
> +#define WMI_GUID_BC			"ABBC0F6F-8EA1-11D1-00A0-C90629100000"
> +#define WMI_DEFAULT_INSTANCE		0x00
> +#define WMI_DEFAULT_METHOD		0x04
> +
> +#define WMI_FUNC_SET_FEATURE		0x00000500
> +#define WMI_FEATURE_LOCAL_DIMMING_OFF	0x0d
> +#define WMI_FEATURE_LOCAL_DIMMING_ON	0x0e
> +
>   /*
>    * Those two registers technically allow for manual fan control,
>    * but are unstable on some models and are likely not meant to
> @@ -332,6 +343,7 @@
>   #define UNIWILL_FEATURE_SECONDARY_FAN		BIT(9)
>   #define UNIWILL_FEATURE_NVIDIA_CTGP_CONTROL	BIT(10)
>   #define UNIWILL_FEATURE_USB_C_POWER_PRIORITY	BIT(11)
> +#define UNIWILL_FEATURE_LOCAL_DIMMING		BIT(12)
>   
>   enum usb_c_power_priority_options {
>   	USB_C_POWER_PRIORITY_CHARGING = 0,
> @@ -367,6 +379,8 @@ struct uniwill_data {
>   	struct notifier_block nb;
>   	struct mutex usb_c_power_priority_lock; /* Protects dependent bit write and state safe */
>   	enum usb_c_power_priority_options last_usb_c_power_priority_option;
> +	struct mutex local_dimming_lock; /* Protects call to local dimming wmi method */
> +	bool last_local_dimming_option;
>   };
>   
>   struct uniwill_battery_entry {
> @@ -774,7 +788,7 @@ static int super_key_enable_init(struct uniwill_data *data)
>   	if (!uniwill_device_supports(data, UNIWILL_FEATURE_SUPER_KEY))
>   		return 0;
>   
> -	return devm_mutex_init(&data->dev, &data->super_key_lock);
> +	return devm_mutex_init(data->dev, &data->super_key_lock);
>   }
>   
>   static int uniwill_write_touchpad_toggle_enable(struct uniwill_data *data, bool status)
> @@ -1086,6 +1100,87 @@ static int usb_c_power_priority_init(struct uniwill_data *data)
>   	return 0;
>   }
>   
> +struct __packed uniwill_wmi_input {
> +	u8 args[4];
> +	u32 function;
> +	/* Prevent accidential out of bounds access by the ACPI code */
> +	u32 reserved[8];
> +};
> +
> +static int set_local_dimming(bool enable)
> +{
> +	struct __packed uniwill_wmi_input wmi_input;
> +	struct acpi_buffer wmi_buf = { (acpi_size) sizeof(wmi_input), &wmi_input };
> +	acpi_status status;
> +
> +	wmi_input.function = WMI_FUNC_SET_FEATURE;
> +	wmi_input.args[0] = enable ? WMI_FEATURE_LOCAL_DIMMING_ON : WMI_FEATURE_LOCAL_DIMMING_OFF;
> +
> +	status = wmi_evaluate_method(WMI_GUID_BC, WMI_DEFAULT_INSTANCE, WMI_DEFAULT_METHOD,
> +				     &wmi_buf, &wmi_buf);

NAK, this API is deprecated and should not be used. Instead we should register a WMI driver during module
initialization that uses wmidev_invoke_method().

Can you share with me the ACPI tables of a device that supports this feature?

Thanks,
Armin Wolf

> +	if (ACPI_FAILURE(status))
> +		return -EIO;
> +
> +	return 0;
> +}
> +
> +static ssize_t local_dimming_store(struct device *dev,
> +				   struct device_attribute *attr,
> +				   const char *buf, size_t count)
> +{
> +	struct uniwill_data *data = dev_get_drvdata(dev);
> +	bool enable;
> +	int ret;
> +
> +	ret = kstrtobool(buf, &enable);
> +	if (ret < 0)
> +		return ret;
> +
> +	guard(mutex)(&data->local_dimming_lock);
> +
> +	ret = set_local_dimming(enable);
> +	if (ret)
> +		return ret;
> +
> +	data->last_local_dimming_option = enable;
> +
> +	return count;
> +}
> +
> +static ssize_t local_dimming_show(struct device *dev,
> +				  struct device_attribute *attr,
> +				  char *buf)
> +{
> +	struct uniwill_data *data = dev_get_drvdata(dev);
> +
> +	return sysfs_emit(buf, "%d\n", data->last_local_dimming_option);
> +}
> +
> +static DEVICE_ATTR_RW(local_dimming);
> +
> +static int local_dimming_restore(struct uniwill_data *data)
> +{
> +	guard(mutex)(&data->local_dimming_lock);
> +
> +	return set_local_dimming(data->last_local_dimming_option);
> +}
> +
> +static int local_dimming_init(struct uniwill_data *data)
> +{
> +	int ret;
> +
> +	if (!uniwill_device_supports(data, UNIWILL_FEATURE_LOCAL_DIMMING))
> +		return 0;
> +
> +	ret = devm_mutex_init(data->dev, &data->local_dimming_lock);
> +	if (ret < 0)
> +		return ret;
> +
> +	data->last_local_dimming_option = 0;
> +
> +	return local_dimming_restore(data);
> +}
> +
>   static struct attribute *uniwill_attrs[] = {
>   	/* Keyboard-related */
>   	&dev_attr_fn_lock.attr,
> @@ -1097,6 +1192,7 @@ static struct attribute *uniwill_attrs[] = {
>   	/* Power-management-related */
>   	&dev_attr_ctgp_offset.attr,
>   	&dev_attr_usb_c_power_priority.attr,
> +	&dev_attr_local_dimming.attr,
>   	NULL
>   };
>   
> @@ -1136,6 +1232,11 @@ static umode_t uniwill_attr_is_visible(struct kobject *kobj, struct attribute *a
>   			return attr->mode;
>   	}
>   
> +	if (attr == &dev_attr_local_dimming.attr) {
> +		if (uniwill_device_supports(data, UNIWILL_FEATURE_LOCAL_DIMMING))
> +			return attr->mode;
> +	}
> +
>   	return 0;
>   }
>   
> @@ -1922,6 +2023,10 @@ static int uniwill_probe(struct platform_device *pdev)
>   	if (ret < 0)
>   		return ret;
>   
> +	ret = local_dimming_init(data);
> +	if (ret < 0)
> +		return ret;
> +
>   	return uniwill_input_init(data);
>   }
>   
> @@ -2075,6 +2180,14 @@ static int uniwill_resume_usb_c_power_priority(struct uniwill_data *data)
>   	return usb_c_power_priority_restore(data);
>   }
>   
> +static int uniwill_resume_local_dimming(struct uniwill_data *data)
> +{
> +	if (!uniwill_device_supports(data, UNIWILL_FEATURE_LOCAL_DIMMING))
> +		return 0;
> +
> +	return local_dimming_restore(data);
> +}
> +
>   static int uniwill_resume(struct device *dev)
>   {
>   	struct uniwill_data *data = dev_get_drvdata(dev);
> @@ -2106,7 +2219,11 @@ static int uniwill_resume(struct device *dev)
>   	if (ret < 0)
>   		return ret;
>   
> -	return uniwill_resume_usb_c_power_priority(data);
> +	ret = uniwill_resume_usb_c_power_priority(data);
> +	if (ret < 0)
> +		return ret;
> +
> +	return uniwill_resume_local_dimming(data);
>   }
>   
>   static DEFINE_SIMPLE_DEV_PM_OPS(uniwill_pm_ops, uniwill_suspend, uniwill_resume);
> @@ -2222,6 +2339,17 @@ static struct uniwill_device_descriptor tux_featureset_3_nvidia_descriptor __ini
>   		    UNIWILL_FEATURE_NVIDIA_CTGP_CONTROL,
>   };
>   
> +static struct uniwill_device_descriptor tux_featureset_3_nvidia_mled_descriptor __initdata = {
> +	.features = UNIWILL_FEATURE_FN_LOCK |
> +		    UNIWILL_FEATURE_SUPER_KEY |
> +		    UNIWILL_FEATURE_CPU_TEMP |
> +		    UNIWILL_FEATURE_GPU_TEMP |
> +		    UNIWILL_FEATURE_PRIMARY_FAN |
> +		    UNIWILL_FEATURE_SECONDARY_FAN |
> +		    UNIWILL_FEATURE_NVIDIA_CTGP_CONTROL |
> +		    UNIWILL_FEATURE_LOCAL_DIMMING,
> +};
> +
>   static int phxtxx1_probe(struct uniwill_data *data)
>   {
>   	unsigned int value;
> @@ -2272,6 +2400,32 @@ static struct uniwill_device_descriptor phxarx1_phxaqf1_descriptor __initdata =
>   	.probe = phxarx1_phxaqf1_probe,
>   };
>   
> +static int x6fr5xxy_probe(struct uniwill_data *data)
> +{
> +	unsigned int value;
> +	int ret;
> +
> +	ret = regmap_read(data->regmap, EC_ADDR_LOCAL_DIMMING_SUPPORT, &value);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (value != 0xff && value & LOCAL_DIMMING_SUPPORT)
> +		data->features |= UNIWILL_FEATURE_LOCAL_DIMMING;
> +
> +	return 0;
> +};
> +
> +static struct uniwill_device_descriptor x6fr5xxy_descriptor __initdata = {
> +	.features = UNIWILL_FEATURE_FN_LOCK |
> +		    UNIWILL_FEATURE_SUPER_KEY |
> +		    UNIWILL_FEATURE_CPU_TEMP |
> +		    UNIWILL_FEATURE_GPU_TEMP |
> +		    UNIWILL_FEATURE_PRIMARY_FAN |
> +		    UNIWILL_FEATURE_SECONDARY_FAN |
> +		    UNIWILL_FEATURE_NVIDIA_CTGP_CONTROL,
> +	.probe = x6fr5xxy_probe,
> +};
> +
>   static struct uniwill_device_descriptor pf5pu1g_descriptor __initdata = {
>   	.features = UNIWILL_FEATURE_FN_LOCK |
>   		    UNIWILL_FEATURE_SUPER_KEY |
> @@ -2662,7 +2816,7 @@ static const struct dmi_system_id uniwill_dmi_table[] __initconst = {
>   			DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
>   			DMI_EXACT_MATCH(DMI_BOARD_NAME, "X6FR5xxY"),
>   		},
> -		.driver_data = &tux_featureset_3_nvidia_descriptor,
> +		.driver_data = &x6fr5xxy_descriptor,
>   	},
>   	{
>   		.ident = "TUXEDO Stellaris 16 Gen7 Intel",
> @@ -2678,7 +2832,7 @@ static const struct dmi_system_id uniwill_dmi_table[] __initconst = {
>   			DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
>   			DMI_EXACT_MATCH(DMI_BOARD_NAME, "X6AR5xxY_mLED"),
>   		},
> -		.driver_data = &tux_featureset_3_nvidia_descriptor,
> +		.driver_data = &tux_featureset_3_nvidia_mled_descriptor,
>   	},
>   	{
>   		.ident = "TUXEDO Book BA15 Gen10 AMD",