Hi Laurent,
On 21/12/2020 01:57, Laurent Pinchart wrote:
> From: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
>
> Extend the existing color management properties to support provision
> of a 3D cubic look up table, allowing for color specific adjustments.
>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> Co-developed-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
Again, for the updates since I created the patch:
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
A bit of a question on clarifying the added documentation but I don't
think it's major.
> ---
> drivers/gpu/drm/drm_atomic_helper.c | 1 +
> drivers/gpu/drm/drm_atomic_state_helper.c | 3 ++
> drivers/gpu/drm/drm_atomic_uapi.c | 10 ++++++
> drivers/gpu/drm/drm_color_mgmt.c | 41 +++++++++++++++++++----
> drivers/gpu/drm/drm_mode_config.c | 14 ++++++++
> include/drm/drm_crtc.h | 9 +++++
> include/drm/drm_mode_config.h | 11 ++++++
> 7 files changed, 82 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index ba1507036f26..0f54897d3c8d 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -3558,6 +3558,7 @@ int drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
> replaced = drm_property_replace_blob(&crtc_state->degamma_lut, NULL);
> replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
> replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, blob);
> + replaced |= drm_property_replace_blob(&crtc_state->cubic_lut, NULL);
> crtc_state->color_mgmt_changed |= replaced;
>
> ret = drm_atomic_commit(state);
> diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
> index ddcf5c2c8e6a..61c685b50677 100644
> --- a/drivers/gpu/drm/drm_atomic_state_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_state_helper.c
> @@ -141,6 +141,8 @@ void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
> drm_property_blob_get(state->ctm);
> if (state->gamma_lut)
> drm_property_blob_get(state->gamma_lut);
> + if (state->cubic_lut)
> + drm_property_blob_get(state->cubic_lut);
> state->mode_changed = false;
> state->active_changed = false;
> state->planes_changed = false;
> @@ -213,6 +215,7 @@ void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
> drm_property_blob_put(state->degamma_lut);
> drm_property_blob_put(state->ctm);
> drm_property_blob_put(state->gamma_lut);
> + drm_property_blob_put(state->cubic_lut);
> }
> EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
>
> diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
> index 268bb69c2e2f..07229acab71c 100644
> --- a/drivers/gpu/drm/drm_atomic_uapi.c
> +++ b/drivers/gpu/drm/drm_atomic_uapi.c
> @@ -471,6 +471,14 @@ static int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
> &replaced);
> state->color_mgmt_changed |= replaced;
> return ret;
> + } else if (property == config->cubic_lut_property) {
> + ret = drm_atomic_replace_property_blob_from_id(dev,
> + &state->cubic_lut,
> + val,
> + -1, sizeof(struct drm_color_lut),
> + &replaced);
> + state->color_mgmt_changed |= replaced;
> + return ret;
> } else if (property == config->prop_out_fence_ptr) {
> s32 __user *fence_ptr = u64_to_user_ptr(val);
>
> @@ -516,6 +524,8 @@ drm_atomic_crtc_get_property(struct drm_crtc *crtc,
> *val = (state->ctm) ? state->ctm->base.id : 0;
> else if (property == config->gamma_lut_property)
> *val = (state->gamma_lut) ? state->gamma_lut->base.id : 0;
> + else if (property == config->cubic_lut_property)
> + *val = (state->cubic_lut) ? state->cubic_lut->base.id : 0;
> else if (property == config->prop_out_fence_ptr)
> *val = 0;
> else if (property == crtc->scaling_filter_property)
> diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c
> index 3bcabc2f6e0e..85bbbc8ce8e5 100644
> --- a/drivers/gpu/drm/drm_color_mgmt.c
> +++ b/drivers/gpu/drm/drm_color_mgmt.c
> @@ -33,7 +33,7 @@
> /**
> * DOC: overview
> *
> - * Color management or color space adjustments is supported through a set of 5
> + * Color management or color space adjustments is supported through a set of 7
> * properties on the &drm_crtc object. They are set up by calling
> * drm_crtc_enable_color_mgmt().
> *
> @@ -60,7 +60,7 @@
> * “CTM”:
> * Blob property to set the current transformation matrix (CTM) apply to
> * pixel data after the lookup through the degamma LUT and before the
> - * lookup through the gamma LUT. The data is interpreted as a struct
> + * lookup through the cubic LUT. The data is interpreted as a struct
> * &drm_color_ctm.
> *
> * Setting this to NULL (blob property value set to 0) means a
> @@ -68,13 +68,40 @@
> * boot-up state too. Drivers can access the blob for the color conversion
> * matrix through &drm_crtc_state.ctm.
> *
> + * ”CUBIC_LUT”:
> + * Blob property to set the cubic (3D) lookup table performing color
> + * mapping after the transformation matrix and before the lookup through
> + * the gamma LUT. Unlike the degamma and gamma LUTs that map color
> + * components independently, the 3D LUT converts an input color to an
> + * output color by indexing into the 3D table using the color components
> + * as a 3D coordinate. The LUT is subsampled as 8-bit (or more) precision
> + * would require too much storage space in the hardware, so the precision
This sentence is a bit confusing. What bit depth is actually used, is it
mandated to a specific subsampling? Or restricted to 8-bit....
> + * of the color components is reduced before the look up, and the low
> + * order bits may be used to interpolate between the nearest points in 3D
> + * space.
> + *
> + * The data is interpreted as an array of &struct drm_color_lut elements.
> + * Hardware might choose not to use the full precision of the LUT
> + * elements.
Is the table already reduced precision though ?
> + *
> + * Setting this to NULL (blob property value set to 0) means the output
> + * color is identical to the input color. This is generally the driver
> + * boot-up state too. Drivers can access this blob through
> + * &drm_crtc_state.cubic_lut.
> + *
> + * ”CUBIC_LUT_SIZE”:
> + * Unsigned range property to give the size of the lookup table to be set
> + * on the CUBIC_LUT property (the size depends on the underlying hardware).
> + * If drivers support multiple LUT sizes then they should publish the
> + * largest size, and sub-sample smaller sized LUTs appropriately.
> + *
> * “GAMMA_LUT”:
> * Blob property to set the gamma lookup table (LUT) mapping pixel data
> - * after the transformation matrix to data sent to the connector. The
> - * data is interpreted as an array of &struct drm_color_lut elements.
> - * Hardware might choose not to use the full precision of the LUT elements
> - * nor use all the elements of the LUT (for example the hardware might
> - * choose to interpolate between LUT[0] and LUT[4]).
> + * after the cubic LUT to data sent to the connector. The data is
> + * interpreted as an array of &struct drm_color_lut elements. Hardware
> + * might choose not to use the full precision of the LUT elements nor use
> + * all the elements of the LUT (for example the hardware might choose to
> + * interpolate between LUT[0] and LUT[4]).
> *
> * Setting this to NULL (blob property value set to 0) means a
> * linear/pass-thru gamma table should be used. This is generally the
> diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
> index f1affc1bb679..6c3324f60e7d 100644
> --- a/drivers/gpu/drm/drm_mode_config.c
> +++ b/drivers/gpu/drm/drm_mode_config.c
> @@ -364,6 +364,20 @@ static int drm_mode_create_standard_properties(struct drm_device *dev)
> return -ENOMEM;
> dev->mode_config.gamma_lut_size_property = prop;
>
> + prop = drm_property_create(dev,
> + DRM_MODE_PROP_BLOB,
> + "CUBIC_LUT", 0);
> + if (!prop)
> + return -ENOMEM;
> + dev->mode_config.cubic_lut_property = prop;
> +
> + prop = drm_property_create_range(dev,
> + DRM_MODE_PROP_IMMUTABLE,
> + "CUBIC_LUT_SIZE", 0, UINT_MAX);
> + if (!prop)
> + return -ENOMEM;
> + dev->mode_config.cubic_lut_size_property = prop;
> +
> prop = drm_property_create(dev,
> DRM_MODE_PROP_IMMUTABLE | DRM_MODE_PROP_BLOB,
> "IN_FORMATS", 0);
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 5f43d64d2a07..df5cc2239adb 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -288,6 +288,15 @@ struct drm_crtc_state {
> */
> struct drm_property_blob *gamma_lut;
>
> + /**
> + * @cubic_lut:
> + *
> + * Cubic Lookup table for converting pixel data. See
> + * drm_crtc_enable_color_mgmt(). The blob (if not NULL) is a 3D array
> + * of &struct drm_color_lut.
> + */
> + struct drm_property_blob *cubic_lut;
> +
> /**
> * @target_vblank:
> *
> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> index ab424ddd7665..8edb0094e5a7 100644
> --- a/include/drm/drm_mode_config.h
> +++ b/include/drm/drm_mode_config.h
> @@ -800,6 +800,17 @@ struct drm_mode_config {
> */
> struct drm_property *gamma_lut_size_property;
>
> + /**
> + * @cubic_lut_property: Optional CRTC property to set the 3D LUT used to
> + * convert color spaces.
> + */
> + struct drm_property *cubic_lut_property;
> + /**
> + * @cubic_lut_size_property: Optional CRTC property for the size of the
> + * 3D LUT as supported by the driver (read-only).
> + */
> + struct drm_property *cubic_lut_size_property;
> +
> /**
> * @suggested_x_property: Optional connector property with a hint for
> * the position of the output on the host's screen.
>
--
Regards
--
Kieran
