Merge tag 'topic/dp-hdmi-2.1-pcon-2020-12-23' of git://anongit.freedesktop.org/drm/drm-intel into drm-next

Add support for DP-HDMI2.1 PCON

From the series cover letter:

This patch series attempts to add support for a DP-HDMI2.1 Protocol
Convertor. The VESA spec for the HDMI2.1 PCON are proposed in Errata
E5 to DisplayPort_v2.0:
https://vesa.org/join-vesamemberships/member-downloads/?action=stamp&fileid=42299
The details are mentioned in:
VESA DP-to-HDMI PCON Specification Standalone Document
https://groups.vesa.org/wg/DP/document/15651

This series starts with adding support for FRL (Fixed Rate Link)
Training between the PCON and HDMI2.1 sink.
As per HDMI2.1 specification, a new data-channel or lane is added in
FRL mode, by repurposing the TMDS clock Channel. Through FRL, higher
bit-rate can be supported, ie. up to 12 Gbps/lane (48 Gbps over 4
lanes).

With these patches, the HDMI2.1 PCON can be configured to achieve FRL
training based on the maximum FRL rate supported by the panel, source
and the PCON.
The approach is to add the support for FRL training between PCON and
HDMI2.1 sink and gradually add other blocks for supporting higher
resolutions and other HDMI2.1 features, that can be supported by pcon
for the sources that do not natively support HDMI2.1.

This is done before the DP Link training between the source and PCON
is started. In case of FRL training is not achieved, the PCON will
work in the regular TMDS mode, without HDMI2.1 feature support.
Any interruption in FRL training between the PCON and HDMI2.1 sink is
notified through IRQ_HPD. On receiving the IRQ_HPD the concerned DPCD
registers are read and FRL training is re-attempted.

Currently, we have tested the FRL training and are able to enable 4K
display with TGL Platform + Realtek PCON RTD2173 with HDMI2.1 supporting
panel.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/87lfdpndkt.fsf@intel.com

1 files changed, 49 insertions, 0 deletions

diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index fcdc58d8b88b..1922b278ffad 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -175,6 +175,46 @@ struct drm_scdc {
 	struct drm_scrambling scrambling;
 };
 
+/**
+ * struct drm_hdmi_dsc_cap - DSC capabilities of HDMI sink
+ *
+ * Describes the DSC support provided by HDMI 2.1 sink.
+ * The information is fetched fom additional HFVSDB blocks defined
+ * for HDMI 2.1.
+ */
+struct drm_hdmi_dsc_cap {
+	/** @v_1p2: flag for dsc1.2 version support by sink */
+	bool v_1p2;
+
+	/** @native_420: Does sink support DSC with 4:2:0 compression */
+	bool native_420;
+
+	/**
+	 * @all_bpp: Does sink support all bpp with 4:4:4: or 4:2:2
+	 * compressed formats
+	 */
+	bool all_bpp;
+
+	/**
+	 * @bpc_supported: compressed bpc supported by sink : 10, 12 or 16 bpc
+	 */
+	u8 bpc_supported;
+
+	/** @max_slices: maximum number of Horizontal slices supported by */
+	u8 max_slices;
+
+	/** @clk_per_slice : max pixel clock in MHz supported per slice */
+	int clk_per_slice;
+
+	/** @max_lanes : dsc max lanes supported for Fixed rate Link training */
+	u8 max_lanes;
+
+	/** @max_frl_rate_per_lane : maximum frl rate with DSC per lane */
+	u8 max_frl_rate_per_lane;
+
+	/** @total_chunk_kbytes: max size of chunks in KBs supported per line*/
+	u8 total_chunk_kbytes;
+};
 
 /**
  * struct drm_hdmi_info - runtime information about the connected HDMI sink
@@ -207,6 +247,15 @@ struct drm_hdmi_info {
 
 	/** @y420_dc_modes: bitmap of deep color support index */
 	u8 y420_dc_modes;
+
+	/** @max_frl_rate_per_lane: support fixed rate link */
+	u8 max_frl_rate_per_lane;
+
+	/** @max_lanes: supported by sink */
+	u8 max_lanes;
+
+	/** @dsc_cap: DSC capabilities of the sink */
+	struct drm_hdmi_dsc_cap dsc_cap;
 };
 
 /**