[PATCH v2 3/5] drm/omap: Implement CTM property for CRTC using OVL managers CPR matrix

[Laurent Pinchart]

Hi Tomi and Jyri,

Thank you for the patch.

On Tue, Nov 03, 2020 at 10:03:08AM +0200, Tomi Valkeinen wrote:
> From: Jyri Sarha <jsarha at ti.com>
> 
> Implement CTM color management property for OMAP CRTC using DSS
> overlay manager's Color Phase Rotation matrix. The CPR matrix does not
> exactly match the CTM property documentation. On DSS the CPR matrix is
> applied after gamma table look up. However, it seems stupid to add a
> custom property just for that.

Should this be updated now that the driver has switched to using degamma
?

> Signed-off-by: Jyri Sarha <jsarha at ti.com>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ti.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> ---
>  drivers/gpu/drm/omapdrm/omap_crtc.c | 39 +++++++++++++++++++++++++++--
>  1 file changed, 37 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c
> index d40220b2f312..b2c251a8b404 100644
> --- a/drivers/gpu/drm/omapdrm/omap_crtc.c
> +++ b/drivers/gpu/drm/omapdrm/omap_crtc.c
> @@ -391,6 +391,33 @@ static void omap_crtc_manual_display_update(struct work_struct *data)
>  	}
>  }
>  
> +static s16 omap_crtc_s31_32_to_s2_8(s64 coef)
> +{
> +	u64 sign_bit = 1ULL << 63;
> +	u64 cbits = (u64)coef;
> +
> +	s16 ret = clamp_val(((cbits & ~sign_bit) >> 24), 0, 0x1ff);
> +
> +	if (cbits & sign_bit)
> +		ret = -ret;
> +
> +	return ret;
> +}
> +
> +static void omap_crtc_cpr_coefs_from_ctm(const struct drm_color_ctm *ctm,
> +					 struct omap_dss_cpr_coefs *cpr)
> +{
> +	cpr->rr = omap_crtc_s31_32_to_s2_8(ctm->matrix[0]);
> +	cpr->rg = omap_crtc_s31_32_to_s2_8(ctm->matrix[1]);
> +	cpr->rb = omap_crtc_s31_32_to_s2_8(ctm->matrix[2]);
> +	cpr->gr = omap_crtc_s31_32_to_s2_8(ctm->matrix[3]);
> +	cpr->gg = omap_crtc_s31_32_to_s2_8(ctm->matrix[4]);
> +	cpr->gb = omap_crtc_s31_32_to_s2_8(ctm->matrix[5]);
> +	cpr->br = omap_crtc_s31_32_to_s2_8(ctm->matrix[6]);
> +	cpr->bg = omap_crtc_s31_32_to_s2_8(ctm->matrix[7]);
> +	cpr->bb = omap_crtc_s31_32_to_s2_8(ctm->matrix[8]);
> +}
> +
>  static void omap_crtc_write_crtc_properties(struct drm_crtc *crtc)
>  {
>  	struct omap_drm_private *priv = crtc->dev->dev_private;
> @@ -402,7 +429,15 @@ static void omap_crtc_write_crtc_properties(struct drm_crtc *crtc)
>  	info.default_color = 0x000000;
>  	info.trans_enabled = false;
>  	info.partial_alpha_enabled = false;
> -	info.cpr_enable = false;
> +
> +	if (crtc->state->ctm) {
> +		struct drm_color_ctm *ctm = crtc->state->ctm->data;
> +
> +		info.cpr_enable = true;
> +		omap_crtc_cpr_coefs_from_ctm(ctm, &info.cpr_coefs);
> +	} else {
> +		info.cpr_enable = false;
> +	}
>  
>  	priv->dispc_ops->mgr_setup(priv->dispc, omap_crtc->channel, &info);
>  }
> @@ -842,7 +877,7 @@ struct drm_crtc *omap_crtc_init(struct drm_device *dev,
>  	if (priv->dispc_ops->mgr_gamma_size(priv->dispc, channel)) {
>  		unsigned int gamma_lut_size = 256;
>  
> -		drm_crtc_enable_color_mgmt(crtc, gamma_lut_size, false, 0);
> +		drm_crtc_enable_color_mgmt(crtc, gamma_lut_size, true, 0);
>  		drm_mode_crtc_set_gamma_size(crtc, gamma_lut_size);
>  	}
>  

-- 
Regards,

Laurent Pinchart