[Intel-gfx] [PATCH 2/7] drm/i915/display: Enable HDR on gen9 devices with MCA Lspcon

[Jani Nikula]

On Fri, 27 Mar 2020, Vipin Anand <vipin.anand at intel.com> wrote:
> From: Uma Shankar <uma.shankar at intel.com>
>
> Gen9 hardware supports HDMI2.0 through LSPCON chips.
> Extending HDR support for MCA LSPCON based GEN9 devices.
>
> SOC will drive LSPCON as DP and send HDR metadata as standard
> DP SDP packets. LSPCON will be set to operate in PCON mode,
> will receive the metadata and create Dynamic Range and
> Mastering Infoframe (DRM packets) and send it to HDR capable
> HDMI sink devices.
>
> v2: Re-used hsw infoframe write implementation for HDR metadata
> for LSPCON as per Ville's suggestion.
>
> Signed-off-by: Uma Shankar <uma.shankar at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_hdmi.c   | 10 ++++++
>  drivers/gpu/drm/i915/display/intel_lspcon.c | 35 +++++++++++++++------
>  drivers/gpu/drm/i915/display/intel_lspcon.h |  5 ++-
>  3 files changed, 39 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
> index 93ac0f296852..9ae2f88cc925 100644
> --- a/drivers/gpu/drm/i915/display/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
> @@ -577,6 +577,16 @@ static u32 hsw_infoframes_enabled(struct intel_encoder *encoder,
>  	return val & mask;
>  }
>  
> +void lspcon_drm_write_infoframe(struct intel_encoder *encoder,
> +	const struct intel_crtc_state *crtc_state,
> +	unsigned int type,
> +	const void *frame, ssize_t len)
> +{
> +	DRM_DEBUG_KMS("Update HDR metadata for lspcon\n");
> +	/* It uses the legacy hsw implementation for the same */
> +	hsw_write_infoframe(encoder, crtc_state, type, frame, len);
> +}

This seems like an unnecessary wrapper.

> +
>  static const u8 infoframe_type_to_idx[] = {
>  	HDMI_PACKET_TYPE_GENERAL_CONTROL,
>  	HDMI_PACKET_TYPE_GAMUT_METADATA,
> diff --git a/drivers/gpu/drm/i915/display/intel_lspcon.c b/drivers/gpu/drm/i915/display/intel_lspcon.c
> index 2e41ae483a23..c5ddabf903d6 100644
> --- a/drivers/gpu/drm/i915/display/intel_lspcon.c
> +++ b/drivers/gpu/drm/i915/display/intel_lspcon.c
> @@ -460,27 +460,42 @@ void lspcon_write_infoframe(struct intel_encoder *encoder,
>  			    unsigned int type,
>  			    const void *frame, ssize_t len)
>  {
> -	bool ret;
> +	bool ret = true;
>  	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
>  	struct intel_lspcon *lspcon = enc_to_intel_lspcon(encoder);
>  
>  	/* LSPCON only needs AVI IF */
> -	if (type != HDMI_INFOFRAME_TYPE_AVI)
> +	if (!(type == HDMI_INFOFRAME_TYPE_AVI ||
> +	      type == HDMI_PACKET_TYPE_GAMUT_METADATA))
>  		return;
>  
> -	if (lspcon->vendor == LSPCON_VENDOR_MCA)
> -		ret = _lspcon_write_avi_infoframe_mca(&intel_dp->aux,
> -						      frame, len);
> -	else
> -		ret = _lspcon_write_avi_infoframe_parade(&intel_dp->aux,
> -							 frame, len);
> +	/*
> +	 * Supporting HDR on MCA LSPCON
> +	 * Todo: Add support for Parade later
> +	 */
> +	if (type == HDMI_PACKET_TYPE_GAMUT_METADATA &&
> +	    lspcon->vendor != LSPCON_VENDOR_MCA)
> +		return;
> +
> +	if (lspcon->vendor == LSPCON_VENDOR_MCA) {
> +		if (type == HDMI_INFOFRAME_TYPE_AVI)
> +			ret = _lspcon_write_avi_infoframe_mca(&intel_dp->aux,
> +							      frame, len);
> +		else if (type == HDMI_PACKET_TYPE_GAMUT_METADATA)
> +			lspcon_drm_write_infoframe(encoder, crtc_state,
> +						   HDMI_PACKET_TYPE_GAMUT_METADATA,
> +						   frame, VIDEO_DIP_DATA_SIZE);
> +	} else {
> +		ret = _lspcon_write_avi_infoframe_parade(&intel_dp->aux, frame,
> +							 len);
> +	}

Seems to me it would be best to replace from the beginning of this
function with something like:

        switch (type) {
        case HDMI_INFOFRAME_TYPE_AVI:
                if (lspcon->vendor == LSPCON_VENDOR_MCA)
                        ...
                else
                        ...
                break;
        case HDMI_PACKET_TYPE_GAMUT_METADATA:
                if (lspcon->vendor == LSPCON_VENDOR_MCA)
                        ...
                else
                        break;
                break;
        default:
                return;
        }

Then it'll be straightforward to replace the actual vendor specific if
ladders with function pointers in struct intel_lspcon in the future.

>  
>  	if (!ret) {
> -		DRM_ERROR("Failed to write AVI infoframes\n");
> +		DRM_ERROR("Failed to write infoframes\n");
>  		return;
>  	}
>  
> -	DRM_DEBUG_DRIVER("AVI infoframes updated successfully\n");
> +	DRM_DEBUG_DRIVER("Infoframes updated successfully\n");
>  }
>  
>  void lspcon_read_infoframe(struct intel_encoder *encoder,
> diff --git a/drivers/gpu/drm/i915/display/intel_lspcon.h b/drivers/gpu/drm/i915/display/intel_lspcon.h
> index 37cfddf8a9c5..b2051f236223 100644
> --- a/drivers/gpu/drm/i915/display/intel_lspcon.h
> +++ b/drivers/gpu/drm/i915/display/intel_lspcon.h
> @@ -34,5 +34,8 @@ u32 lspcon_infoframes_enabled(struct intel_encoder *encoder,
>  			      const struct intel_crtc_state *pipe_config);
>  void lspcon_ycbcr420_config(struct drm_connector *connector,
>  			    struct intel_crtc_state *crtc_state);
> -
> +void lspcon_drm_write_infoframe(struct intel_encoder *encoder,
> +				const struct intel_crtc_state *crtc_state,
> +				unsigned int type,
> +				const void *frame, ssize_t len);
>  #endif /* __INTEL_LSPCON_H__ */

-- 
Jani Nikula, Intel Open Source Graphics Center