[PATCH v4 06/32] drm/amd/display: explicitly define EOTF and inverse EOTF

Harry Wentland harry.wentland at amd.com
Wed Nov 15 18:25:57 UTC 2023



On 2023-10-05 13:15, Melissa Wen wrote:
> Instead of relying on color block names to get the transfer function
> intention regarding encoding pixel's luminance, define supported
> Electro-Optical Transfer Functions (EOTFs) and inverse EOTFs, that
> includes pure gamma or standardized transfer functions.
> 
> v3:
> - squash linear and unity TFs to identity (Pekka)
> - define the right TFs for BT.709 (Pekka and Harry)
> - add comment about AMD TF coefficients
> 
> Suggested-by: Harry Wentland <harry.wentland at amd.com>
> Signed-off-by: Melissa Wen <mwen at igalia.com>

Reviewed-by: Harry Wentland <harry.wentland at amd.com>

Harry

> ---
>  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 27 +++++---
>  .../amd/display/amdgpu_dm/amdgpu_dm_color.c   | 67 ++++++++++++++-----
>  2 files changed, 71 insertions(+), 23 deletions(-)
> 
> 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 4c4cdf7fc6be..fc4f188d397e 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> @@ -724,16 +724,27 @@ struct amdgpu_dm_wb_connector {
>  
>  extern const struct amdgpu_ip_block_version dm_ip_block;
>  
> +/* enum amdgpu_transfer_function: pre-defined transfer function supported by AMD.
> + *
> + * It includes standardized transfer functions and pure power functions. The
> + * transfer function coefficients are available at modules/color/color_gamma.c
> + */
>  enum amdgpu_transfer_function {
>  	AMDGPU_TRANSFER_FUNCTION_DEFAULT,
> -	AMDGPU_TRANSFER_FUNCTION_SRGB,
> -	AMDGPU_TRANSFER_FUNCTION_BT709,
> -	AMDGPU_TRANSFER_FUNCTION_PQ,
> -	AMDGPU_TRANSFER_FUNCTION_LINEAR,
> -	AMDGPU_TRANSFER_FUNCTION_UNITY,
> -	AMDGPU_TRANSFER_FUNCTION_GAMMA22,
> -	AMDGPU_TRANSFER_FUNCTION_GAMMA24,
> -	AMDGPU_TRANSFER_FUNCTION_GAMMA26,
> +	AMDGPU_TRANSFER_FUNCTION_SRGB_EOTF,
> +	AMDGPU_TRANSFER_FUNCTION_BT709_INV_OETF,
> +	AMDGPU_TRANSFER_FUNCTION_PQ_EOTF,
> +	AMDGPU_TRANSFER_FUNCTION_IDENTITY,
> +	AMDGPU_TRANSFER_FUNCTION_GAMMA22_EOTF,
> +	AMDGPU_TRANSFER_FUNCTION_GAMMA24_EOTF,
> +	AMDGPU_TRANSFER_FUNCTION_GAMMA26_EOTF,
> +	AMDGPU_TRANSFER_FUNCTION_SRGB_INV_EOTF,
> +	AMDGPU_TRANSFER_FUNCTION_BT709_OETF,
> +	AMDGPU_TRANSFER_FUNCTION_PQ_INV_EOTF,
> +	AMDGPU_TRANSFER_FUNCTION_GAMMA22_INV_EOTF,
> +	AMDGPU_TRANSFER_FUNCTION_GAMMA24_INV_EOTF,
> +	AMDGPU_TRANSFER_FUNCTION_GAMMA26_INV_EOTF,
> +        AMDGPU_TRANSFER_FUNCTION_COUNT
>  };
>  
>  struct dm_plane_state {
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
> index 56ce008b9095..d03bdb010e8b 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
> @@ -85,18 +85,57 @@ void amdgpu_dm_init_color_mod(void)
>  }
>  
>  #ifdef AMD_PRIVATE_COLOR
> -static const struct drm_prop_enum_list amdgpu_transfer_function_enum_list[] = {
> -	{ AMDGPU_TRANSFER_FUNCTION_DEFAULT, "Default" },
> -	{ AMDGPU_TRANSFER_FUNCTION_SRGB, "sRGB" },
> -	{ AMDGPU_TRANSFER_FUNCTION_BT709, "BT.709" },
> -	{ AMDGPU_TRANSFER_FUNCTION_PQ, "PQ (Perceptual Quantizer)" },
> -	{ AMDGPU_TRANSFER_FUNCTION_LINEAR, "Linear" },
> -	{ AMDGPU_TRANSFER_FUNCTION_UNITY, "Unity" },
> -	{ AMDGPU_TRANSFER_FUNCTION_GAMMA22, "Gamma 2.2" },
> -	{ AMDGPU_TRANSFER_FUNCTION_GAMMA24, "Gamma 2.4" },
> -	{ AMDGPU_TRANSFER_FUNCTION_GAMMA26, "Gamma 2.6" },
> +static const char * const
> +amdgpu_transfer_function_names[] = {
> +	[AMDGPU_TRANSFER_FUNCTION_DEFAULT]		= "Default",
> +	[AMDGPU_TRANSFER_FUNCTION_IDENTITY]		= "Identity",
> +	[AMDGPU_TRANSFER_FUNCTION_SRGB_EOTF]		= "sRGB EOTF",
> +	[AMDGPU_TRANSFER_FUNCTION_BT709_INV_OETF]	= "BT.709 inv_OETF",
> +	[AMDGPU_TRANSFER_FUNCTION_PQ_EOTF]		= "PQ EOTF",
> +	[AMDGPU_TRANSFER_FUNCTION_GAMMA22_EOTF]		= "Gamma 2.2 EOTF",
> +	[AMDGPU_TRANSFER_FUNCTION_GAMMA24_EOTF]		= "Gamma 2.4 EOTF",
> +	[AMDGPU_TRANSFER_FUNCTION_GAMMA26_EOTF]		= "Gamma 2.6 EOTF",
> +	[AMDGPU_TRANSFER_FUNCTION_SRGB_INV_EOTF]	= "sRGB inv_EOTF",
> +	[AMDGPU_TRANSFER_FUNCTION_BT709_OETF]		= "BT.709 OETF",
> +	[AMDGPU_TRANSFER_FUNCTION_PQ_INV_EOTF]		= "PQ inv_EOTF",
> +	[AMDGPU_TRANSFER_FUNCTION_GAMMA22_INV_EOTF]	= "Gamma 2.2 inv_EOTF",
> +	[AMDGPU_TRANSFER_FUNCTION_GAMMA24_INV_EOTF]	= "Gamma 2.4 inv_EOTF",
> +	[AMDGPU_TRANSFER_FUNCTION_GAMMA26_INV_EOTF]	= "Gamma 2.6 inv_EOTF",
>  };
>  
> +static const u32 amdgpu_eotf =
> +	BIT(AMDGPU_TRANSFER_FUNCTION_SRGB_EOTF) |
> +	BIT(AMDGPU_TRANSFER_FUNCTION_BT709_INV_OETF) |
> +	BIT(AMDGPU_TRANSFER_FUNCTION_PQ_EOTF) |
> +	BIT(AMDGPU_TRANSFER_FUNCTION_GAMMA22_EOTF) |
> +	BIT(AMDGPU_TRANSFER_FUNCTION_GAMMA24_EOTF) |
> +	BIT(AMDGPU_TRANSFER_FUNCTION_GAMMA26_EOTF);
> +
> +static struct drm_property *
> +amdgpu_create_tf_property(struct drm_device *dev,
> +			  const char *name,
> +			  u32 supported_tf)
> +{
> +	u32 transfer_functions = supported_tf |
> +				 BIT(AMDGPU_TRANSFER_FUNCTION_DEFAULT) |
> +				 BIT(AMDGPU_TRANSFER_FUNCTION_IDENTITY);
> +	struct drm_prop_enum_list enum_list[AMDGPU_TRANSFER_FUNCTION_COUNT];
> +	int i, len;
> +
> +	len = 0;
> +	for (i = 0; i < AMDGPU_TRANSFER_FUNCTION_COUNT; i++) {
> +		if ((transfer_functions & BIT(i)) == 0)
> +			continue;
> +
> +		enum_list[len].type = i;
> +		enum_list[len].name = amdgpu_transfer_function_names[i];
> +		len++;
> +	}
> +
> +	return drm_property_create_enum(dev, DRM_MODE_PROP_ENUM,
> +					name, enum_list, len);
> +}
> +
>  int
>  amdgpu_dm_create_color_properties(struct amdgpu_device *adev)
>  {
> @@ -116,11 +155,9 @@ amdgpu_dm_create_color_properties(struct amdgpu_device *adev)
>  		return -ENOMEM;
>  	adev->mode_info.plane_degamma_lut_size_property = prop;
>  
> -	prop = drm_property_create_enum(adev_to_drm(adev),
> -					DRM_MODE_PROP_ENUM,
> -					"AMD_PLANE_DEGAMMA_TF",
> -					amdgpu_transfer_function_enum_list,
> -					ARRAY_SIZE(amdgpu_transfer_function_enum_list));
> +	prop = amdgpu_create_tf_property(adev_to_drm(adev),
> +					 "AMD_PLANE_DEGAMMA_TF",
> +					 amdgpu_eotf);
>  	if (!prop)
>  		return -ENOMEM;
>  	adev->mode_info.plane_degamma_tf_property = prop;



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