Re: [PATCH v2 2/5] drm/amd: Pass luminance data to amdgpu_dm_backlight_caps

[Alex Hung <alex.hung@amd.com>]

Reviewed-by: Alex Hung <alex.hung@amd.com>

On 2/28/25 11:51, Mario Limonciello wrote:
> The ATIF method on some systems will provide a backlight curve. Pass
> this curve into amdgpu_dm add it to the structures.
> 
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> v2:
>   * Keep ACPI and DM structures separate
>   * Add static asserts to ensure structures remain in sync
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c      |  4 ++++
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 20 +++++++++++++++++++
>   drivers/gpu/drm/amd/include/amd_acpi.h        |  4 +++-
>   3 files changed, 27 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
> index 515c6f32448d..b7f8f2ff143d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
> @@ -394,6 +394,10 @@ static int amdgpu_atif_query_backlight_caps(struct amdgpu_atif *atif)
>   			characteristics.max_input_signal;
>   	atif->backlight_caps.ac_level = characteristics.ac_level;
>   	atif->backlight_caps.dc_level = characteristics.dc_level;
> +	atif->backlight_caps.data_points = characteristics.number_of_points;
> +	memcpy(atif->backlight_caps.luminance_data,
> +	       characteristics.data_points,
> +	       sizeof(atif->backlight_caps.luminance_data));
>   out:
>   	kfree(info);
>   	return err;
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> index f3bc00e587ad..85b64c457ed6 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> @@ -151,6 +151,18 @@ struct idle_workqueue {
>   	bool running;
>   };
>   
> +#define MAX_LUMINANCE_DATA_POINTS 99
> +
> +/**
> + * struct amdgpu_dm_luminance_data - Custom luminance data
> + * @luminance: Luminance in percent
> + * @input_signal: Input signal in range 0-255
> + */
> +struct amdgpu_dm_luminance_data {
> +	u8 luminance;
> +	u8 input_signal;
> +} __packed;
> +
>   /**
>    * struct amdgpu_dm_backlight_caps - Information about backlight
>    *
> @@ -195,6 +207,14 @@ struct amdgpu_dm_backlight_caps {
>   	 * @dc_level: the default brightness if booted on DC
>   	 */
>   	u8 dc_level;
> +	/**
> +	 * @data_points: the number of custom luminance data points
> +	 */
> +	u8 data_points;
> +	/**
> +	 * @luminance_data: custom luminance data
> +	 */
> +	struct amdgpu_dm_luminance_data luminance_data[MAX_LUMINANCE_DATA_POINTS];
>   };
>   
>   /**
> diff --git a/drivers/gpu/drm/amd/include/amd_acpi.h b/drivers/gpu/drm/amd/include/amd_acpi.h
> index 2d089d30518f..06badbf0c5b9 100644
> --- a/drivers/gpu/drm/amd/include/amd_acpi.h
> +++ b/drivers/gpu/drm/amd/include/amd_acpi.h
> @@ -61,7 +61,7 @@ struct atif_qbtc_arguments {
>   
>   struct atif_qbtc_data_point {
>   	u8 luminance;		/* luminance in percent */
> -	u8 ipnut_signal;	/* input signal in range 0-255 */
> +	u8 input_signal;	/* input signal in range 0-255 */
>   } __packed;
>   
>   struct atif_qbtc_output {
> @@ -75,6 +75,8 @@ struct atif_qbtc_output {
>   	u8 number_of_points;	/* number of data points */
>   	struct atif_qbtc_data_point data_points[ATIF_QBTC_MAX_DATA_POINTS];
>   } __packed;
> +static_assert(ATIF_QBTC_MAX_DATA_POINTS == MAX_LUMINANCE_DATA_POINTS);
> +static_assert(sizeof(struct atif_qbtc_data_point) == sizeof(struct amdgpu_dm_luminance_data));
>   
>   #define ATIF_NOTIFY_MASK	0x3
>   #define ATIF_NOTIFY_NONE	0