[Intel-gfx] [v8 3/5] drm/edid: read HF-EEODB ext block

[Lee Shawn C <shawn.c.lee@intel.com>]

According to HDMI 2.1 spec.

"The HDMI Forum EDID Extension Override Data Block (HF-EEODB)
is utilized by Sink Devices to provide an alternate method to
indicate an EDID Extension Block count larger than 1, while
avoiding the need to present a VESA Block Map in the first
E-EDID Extension Block."

It is a mandatory for HDMI 2.1 protocol compliance as well.
This patch help to know how many HF_EEODB blocks report by sink
and read allo HF_EEODB blocks back.

v2: support to find CEA block, check EEODB block format, and return
    available block number in drm_edid_read_hf_eeodb_blk_count().

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Cc: intel-gfx <intel-gfx@lists.freedesktop.org>
Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com>
---
 drivers/gpu/drm/drm_connector.c |  8 +++-
 drivers/gpu/drm/drm_edid.c      | 71 +++++++++++++++++++++++++++++++--
 include/drm/drm_edid.h          |  2 +-
 3 files changed, 74 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index a50c82bc2b2f..16011023c12e 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2129,7 +2129,7 @@ int drm_connector_update_edid_property(struct drm_connector *connector,
 				       const struct edid *edid)
 {
 	struct drm_device *dev = connector->dev;
-	size_t size = 0;
+	size_t size = 0, hf_eeodb_blk_count;
 	int ret;
 	const struct edid *old_edid;
 
@@ -2137,8 +2137,12 @@ int drm_connector_update_edid_property(struct drm_connector *connector,
 	if (connector->override_edid)
 		return 0;
 
-	if (edid)
+	if (edid) {
 		size = EDID_LENGTH * (1 + edid->extensions);
+		hf_eeodb_blk_count = drm_edid_read_hf_eeodb_blk_count(edid);
+		if (hf_eeodb_blk_count)
+			size = EDID_LENGTH * (1 + hf_eeodb_blk_count);
+	}
 
 	/* Set the display info, using edid if available, otherwise
 	 * resetting the values to defaults. This duplicates the work
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index ef65dd97d700..890038758660 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1992,6 +1992,7 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
 {
 	int i, j = 0, valid_extensions = 0;
 	u8 *edid, *new;
+	size_t hf_eeodb_blk_count;
 	struct edid *override;
 
 	override = drm_get_override_edid(connector);
@@ -2051,7 +2052,35 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
 		}
 
 		kfree(edid);
+		return (struct edid *)new;
+	}
+
+	hf_eeodb_blk_count = drm_edid_read_hf_eeodb_blk_count((struct edid *)edid);
+	if (hf_eeodb_blk_count >= 2) {
+		new = krealloc(edid, (hf_eeodb_blk_count + 1) * EDID_LENGTH, GFP_KERNEL);
+		if (!new)
+			goto out;
 		edid = new;
+
+		valid_extensions = hf_eeodb_blk_count - 1;
+		for (j = 2; j <= hf_eeodb_blk_count; j++) {
+			u8 *block = edid + j * EDID_LENGTH;
+
+			for (i = 0; i < 4; i++) {
+				if (get_edid_block(data, block, j, EDID_LENGTH))
+					goto out;
+				if (drm_edid_block_valid(block, j, false, NULL))
+					break;
+			}
+
+			if (i == 4)
+				valid_extensions--;
+		}
+
+		if (valid_extensions != hf_eeodb_blk_count - 1) {
+			DRM_ERROR("Not able to retrieve proper EDID contain HF-EEODB data.\n");
+			goto out;
+		}
 	}
 
 	return (struct edid *)edid;
@@ -3315,15 +3344,17 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
 #define VIDEO_BLOCK     0x02
 #define VENDOR_BLOCK    0x03
 #define SPEAKER_BLOCK	0x04
-#define HDR_STATIC_METADATA_BLOCK	0x6
-#define USE_EXTENDED_TAG 0x07
-#define EXT_VIDEO_CAPABILITY_BLOCK 0x00
+#define EXT_VIDEO_CAPABILITY_BLOCK	0x00
+#define HDR_STATIC_METADATA_BLOCK	0x06
+#define USE_EXTENDED_TAG		0x07
 #define EXT_VIDEO_DATA_BLOCK_420	0x0E
-#define EXT_VIDEO_CAP_BLOCK_Y420CMDB 0x0F
+#define EXT_VIDEO_CAP_BLOCK_Y420CMDB	0x0F
+#define EXT_VIDEO_HF_EEODB_DATA_BLOCK	0x78
 #define EDID_BASIC_AUDIO	(1 << 6)
 #define EDID_CEA_YCRCB444	(1 << 5)
 #define EDID_CEA_YCRCB422	(1 << 4)
 #define EDID_CEA_VCDB_QS	(1 << 6)
+#define HF_EEODB_LENGTH		2
 
 /*
  * Search EDID for CEA extension block.
@@ -4273,9 +4304,41 @@ static bool cea_db_is_y420vdb(const u8 *db)
 	return true;
 }
 
+static bool cea_db_is_hdmi_forum_eeodb(const u8 *db)
+{
+	if (cea_db_tag(db) != USE_EXTENDED_TAG)
+		return false;
+
+	if (cea_db_payload_len(db) != HF_EEODB_LENGTH)
+		return false;
+
+	if (cea_db_extended_tag(db) != EXT_VIDEO_HF_EEODB_DATA_BLOCK)
+		return false;
+
+	return true;
+}
+
 #define for_each_cea_db(cea, i, start, end) \
 	for ((i) = (start); (i) < (end) && (i) + cea_db_payload_len(&(cea)[(i)]) < (end); (i) += cea_db_payload_len(&(cea)[(i)]) + 1)
 
+size_t drm_edid_read_hf_eeodb_blk_count(const struct edid *edid)
+{
+	const u8 *cea;
+	int i, start, end, ext_index = 0;
+
+	if (edid->extensions) {
+		cea = drm_find_cea_extension(edid, &ext_index);
+
+		if (cea && !cea_db_offsets(cea, &start, &end))
+			for_each_cea_db(cea, i, start, end)
+				if (cea_db_is_hdmi_forum_eeodb(&cea[i]))
+					return cea[i + 2];
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_edid_read_hf_eeodb_blk_count);
+
 static void drm_parse_y420cmdb_bitmap(struct drm_connector *connector,
 				      const u8 *db)
 {
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 144c495b99c4..5549da7bd7be 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -592,6 +592,6 @@ drm_display_mode_from_cea_vic(struct drm_device *dev,
 			      u8 video_code);
 const u8 *drm_find_edid_extension(const struct edid *edid,
 				  int ext_id, int *ext_index);
-
+size_t drm_edid_read_hf_eeodb_blk_count(const struct edid *edid);
 
 #endif /* __DRM_EDID_H__ */
-- 
2.17.1