[v6 03/13] drm: Parse Colorimetry data block from EDID

[Uma Shankar]

CEA 861.3 spec adds colorimetry data block for HDMI.
Parsing the block to get the colorimetry data from
panel.

v2: Rebase

v3: No Change

v4: Addressed Shashank's review comments. Updated
colorimetry field to 16 bit as DCI-P3 got added
in CEA 861-G spec, as pointed out by Shashank.

v5: Fixed checkpatch warnings with --strict option.

Signed-off-by: Uma Shankar <uma.shankar at intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma at intel.com>
---
 drivers/gpu/drm/drm_edid.c  | 25 +++++++++++++++++++++++++
 include/drm/drm_connector.h |  3 +++
 2 files changed, 28 insertions(+)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index fd8a621a..676569b 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2840,6 +2840,7 @@ static int drm_cvt_modes(struct drm_connector *connector,
 #define VIDEO_BLOCK     0x02
 #define VENDOR_BLOCK    0x03
 #define SPEAKER_BLOCK	0x04
+#define COLORIMETRY_DATA_BLOCK		0x5
 #define HDR_STATIC_METADATA_BLOCK	0x6
 #define USE_EXTENDED_TAG 0x07
 #define EXT_VIDEO_CAPABILITY_BLOCK 0x00
@@ -3829,6 +3830,28 @@ static void fixup_detailed_cea_mode_clock(struct drm_display_mode *mode)
 	mode->clock = clock;
 }
 
+static bool cea_db_is_hdmi_colorimetry_data_block(const u8 *db)
+{
+	if (cea_db_tag(db) != USE_EXTENDED_TAG)
+		return false;
+
+	if (db[1] != COLORIMETRY_DATA_BLOCK)
+		return false;
+
+	return true;
+}
+
+static void
+drm_parse_colorimetry_data_block(struct drm_connector *connector, const u8 *db)
+{
+	struct drm_hdmi_info *info = &connector->display_info.hdmi;
+	u16 len;
+
+	len = cea_db_payload_len_ext(db);
+	/* As per CEA 861-G spec */
+	info->colorimetry = ((db[3] & (0x1 << 7)) << 1) | db[2];
+}
+
 static bool cea_db_is_hdmi_hdr_metadata_block(const u8 *db)
 {
 	if (cea_db_tag(db) != USE_EXTENDED_TAG)
@@ -4498,6 +4521,8 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
 			drm_parse_vcdb(connector, db);
 		if (cea_db_is_hdmi_hdr_metadata_block(db))
 			drm_parse_hdr_metadata_block(connector, db);
+		if (cea_db_is_hdmi_colorimetry_data_block(db))
+			drm_parse_colorimetry_data_block(connector, db);
 	}
 }
 
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 29388bd..94f926e 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -206,6 +206,9 @@ struct drm_hdmi_info {
 
 	/** @y420_dc_modes: bitmap of deep color support index */
 	u8 y420_dc_modes;
+
+	/* @colorimetry: bitmap of supported colorimetry modes */
+	u16 colorimetry;
 };
 
 /**
-- 
1.9.1