drm: edid: add support for parsing additional EDID blocks

Currently the DRM upstream EDID parser doesn't have support to
parse all EDID blocks such as extension tag blocks.

Add support for parsing these blocks and extract necessary info.

Change-Id: Iae92de79960f6f0e73a8e2ff7944c1bf101d90a6
Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>

1 files changed, 238 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 8714643ccee8..02a60a1df50d 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -89,6 +89,14 @@ struct detailed_mode_closure {
 #define LEVEL_GTF2	2
 #define LEVEL_CVT	3
 
+/*Enum storing luminance types for HDR blocks in EDID*/
+enum luminance_value {
+	NO_LUMINANCE_DATA = 3,
+	MAXIMUM_LUMINANCE = 4,
+	FRAME_AVERAGE_LUMINANCE = 5,
+	MINIMUM_LUMINANCE = 6
+};
+
 static struct edid_quirk {
 	char vendor[4];
 	int product_id;
@@ -2697,12 +2705,15 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
 
 	return closure.modes;
 }
-
+#define VIDEO_CAPABILITY_EXTENDED_DATA_BLOCK 0x0
 #define AUDIO_BLOCK	0x01
 #define VIDEO_BLOCK     0x02
 #define VENDOR_BLOCK    0x03
 #define SPEAKER_BLOCK	0x04
+#define HDR_STATIC_METADATA_EXTENDED_DATA_BLOCK 0x06
+#define EXTENDED_TAG  0x07
 #define VIDEO_CAPABILITY_BLOCK	0x07
+#define Y420_VIDEO_DATA_BLOCK	0x0E
 #define EDID_BASIC_AUDIO	(1 << 6)
 #define EDID_CEA_YCRCB444	(1 << 5)
 #define EDID_CEA_YCRCB422	(1 << 4)
@@ -3460,6 +3471,227 @@ parse_hdmi_hf_vsdb(struct drm_connector *connector, const u8 *db)
 }
 
 static void
+drm_hdmi_extract_vsdbs_info(struct drm_connector *connector, struct edid *edid)
+{
+	const u8 *cea = drm_find_cea_extension(edid);
+	const u8 *db = NULL;
+
+	if (cea && cea_revision(cea) >= 3) {
+		int i, start, end;
+
+		if (cea_db_offsets(cea, &start, &end))
+			return;
+
+		for_each_cea_db(cea, i, start, end) {
+			db = &cea[i];
+
+			if (cea_db_tag(db) == VENDOR_BLOCK) {
+				/* HDMI Vendor-Specific Data Block */
+				if (cea_db_is_hdmi_vsdb(db))
+					parse_hdmi_vsdb(connector, db);
+				/* HDMI Forum Vendor-Specific Data Block */
+				else if (cea_db_is_hdmi_hf_vsdb(db))
+					parse_hdmi_hf_vsdb(connector, db);
+			}
+		}
+	}
+}
+
+/*
+ * drm_extract_vcdb_info - Parse the HDMI Video Capability Data Block
+ * @connector: connector corresponding to the HDMI sink
+ * @db: start of the CEA vendor specific block
+ *
+ * Parses the HDMI VCDB to extract sink info for @connector.
+ */
+static void
+drm_extract_vcdb_info(struct drm_connector *connector, const u8 *db)
+{
+	/*
+	 * Check if the sink specifies underscan
+	 * support for:
+	 * BIT 5: preferred video format
+	 * BIT 3: IT video format
+	 * BIT 1: CE video format
+	 */
+
+	connector->pt_scan_info =
+		(db[2] & (BIT(4) | BIT(5))) >> 4;
+	connector->it_scan_info =
+		(db[2] & (BIT(3) | BIT(2))) >> 2;
+	connector->ce_scan_info =
+		db[2] & (BIT(1) | BIT(0));
+
+	DRM_DEBUG_KMS("Scan Info (pt|it|ce): (%d|%d|%d)",
+			  (int) connector->pt_scan_info,
+			  (int) connector->it_scan_info,
+			  (int) connector->ce_scan_info);
+}
+
+static bool drm_edid_is_luminance_value_present(
+u32 block_length, enum luminance_value value)
+{
+	return block_length > NO_LUMINANCE_DATA && value <= block_length;
+}
+
+/*
+ * drm_extract_hdr_db - Parse the HDMI HDR extended block
+ * @connector: connector corresponding to the HDMI sink
+ * @db: start of the HDMI HDR extended block
+ *
+ * Parses the HDMI HDR extended block to extract sink info for @connector.
+ */
+static void
+drm_extract_hdr_db(struct drm_connector *connector, const u8 *db)
+{
+
+	u8 len = 0;
+
+	if (!db) {
+		DRM_ERROR("invalid db\n");
+		return;
+	}
+
+	len = db[0] & 0x1f;
+	/* Byte 3: Electro-Optical Transfer Functions */
+	connector->hdr_eotf = db[2] & 0x3F;
+
+	/* Byte 4: Static Metadata Descriptor Type 1 */
+	connector->hdr_metadata_type_one = (db[3] & BIT(0));
+
+	/* Byte 5: Desired Content Maximum Luminance */
+	if (drm_edid_is_luminance_value_present(len, MAXIMUM_LUMINANCE))
+		connector->hdr_max_luminance =
+			db[MAXIMUM_LUMINANCE];
+
+	/* Byte 6: Desired Content Max Frame-average Luminance */
+	if (drm_edid_is_luminance_value_present(len, FRAME_AVERAGE_LUMINANCE))
+		connector->hdr_avg_luminance =
+			db[FRAME_AVERAGE_LUMINANCE];
+
+	/* Byte 7: Desired Content Min Luminance */
+	if (drm_edid_is_luminance_value_present(len, MINIMUM_LUMINANCE))
+		connector->hdr_min_luminance =
+			db[MINIMUM_LUMINANCE];
+
+	connector->hdr_supported = true;
+
+	DRM_DEBUG_KMS("HDR electro-optical %d\n", connector->hdr_eotf);
+	DRM_DEBUG_KMS("metadata desc 1 %d\n", connector->hdr_metadata_type_one);
+	DRM_DEBUG_KMS("max luminance %d\n", connector->hdr_max_luminance);
+	DRM_DEBUG_KMS("avg luminance %d\n", connector->hdr_avg_luminance);
+	DRM_DEBUG_KMS("min luminance %d\n", connector->hdr_min_luminance);
+}
+
+/*
+ * drm_hdmi_extract_extended_blk_info - Parse the HDMI extended tag blocks
+ * @connector: connector corresponding to the HDMI sink
+ * @edid: handle to the EDID structure
+ * Parses the all extended tag blocks extract sink info for @connector.
+ */
+static void
+drm_hdmi_extract_extended_blk_info(struct drm_connector *connector,
+struct edid *edid)
+{
+	const u8 *cea = drm_find_cea_extension(edid);
+	const u8 *db = NULL;
+
+	if (cea && cea_revision(cea) >= 3) {
+		int i, start, end;
+
+		if (cea_db_offsets(cea, &start, &end))
+			return;
+
+		for_each_cea_db(cea, i, start, end) {
+			db = &cea[i];
+
+			if (cea_db_tag(db) == EXTENDED_TAG) {
+				DRM_DEBUG_KMS("found extended tag block = %d\n",
+				db[1]);
+				switch (db[1]) {
+				case VIDEO_CAPABILITY_EXTENDED_DATA_BLOCK:
+					drm_extract_vcdb_info(connector, db);
+					break;
+				case HDR_STATIC_METADATA_EXTENDED_DATA_BLOCK:
+					drm_extract_hdr_db(connector, db);
+					break;
+				default:
+					break;
+				}
+			}
+		}
+	}
+}
+
+static u8 *
+drm_edid_find_extended_tag_block(struct edid *edid, int blk_id)
+{
+	u8 *db = NULL;
+	u8 *cea = NULL;
+
+	if (!edid) {
+		pr_err("%s: invalid input\n", __func__);
+		return NULL;
+	}
+
+	cea = drm_find_cea_extension(edid);
+
+	if (cea && cea_revision(cea) >= 3) {
+		int i, start, end;
+
+		if (cea_db_offsets(cea, &start, &end))
+			return NULL;
+
+		for_each_cea_db(cea, i, start, end) {
+			db = &cea[i];
+			if ((cea_db_tag(db) == EXTENDED_TAG) &&
+				(db[1] == blk_id))
+				return db;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * add_YCbCr420VDB_modes - add the modes found in Ycbcr420 VDB block
+ * @connector: connector corresponding to the HDMI sink
+ * @edid: handle to the EDID structure
+ * Parses the YCbCr420 VDB block and adds the modes to @connector.
+ */
+static int
+add_YCbCr420VDB_modes(struct drm_connector *connector, struct edid *edid)
+{
+
+	const u8 *db = NULL;
+	u32 i = 0;
+	u32 modes = 0;
+	u32 video_format = 0;
+	u8 len = 0;
+
+	/*Find the YCbCr420 VDB*/
+	db = drm_edid_find_extended_tag_block(edid, Y420_VIDEO_DATA_BLOCK);
+	/* Offset to byte 3 */
+	if (db) {
+		len = db[0] & 0x1F;
+		db += 2;
+		for (i = 0; i < len - 1; i++) {
+			struct drm_display_mode *mode;
+
+			video_format = *(db + i) & 0x7F;
+			mode = drm_display_mode_from_vic_index(connector,
+					db, len-1, i);
+			if (mode) {
+				DRM_DEBUG_KMS("Adding mode for vic = %d\n",
+				video_format);
+				drm_mode_probed_add(connector, mode);
+				modes++;
+			}
+		}
+	}
+	return modes;
+}
+
+static void
 monitor_name(struct detailed_timing *t, void *data)
 {
 	if (t->data.other_data.type == EDID_DETAIL_MONITOR_NAME)
@@ -3997,6 +4229,10 @@ static void drm_add_display_info(struct edid *edid,
 			info->color_formats |= DRM_COLOR_FORMAT_YCRCB422;
 	}
 
+	/* Extract audio and video latency fields for the sink */
+	drm_hdmi_extract_vsdbs_info(connector, edid);
+	/* Extract info from extended tag blocks */
+	drm_hdmi_extract_extended_blk_info(connector, edid);
 	/* HDMI deep color modes supported? Assign to info, if so */
 	drm_assign_hdmi_deep_color_info(edid, info, connector);
 
@@ -4227,6 +4463,7 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
 	num_modes += add_cea_modes(connector, edid);
 	num_modes += add_alternate_cea_modes(connector, edid);
 	num_modes += add_displayid_detailed_modes(connector, edid);
+	num_modes += add_YCbCr420VDB_modes(connector, edid);
 	if (edid->features & DRM_EDID_FEATURE_DEFAULT_GTF)
 		num_modes += add_inferred_modes(connector, edid);