[PATCH v3 2/3] drm: parse hf-vsdb

[Shashank Sharma]

HDMI 2.0 / CEA-861-F specs define a new CEA extension data block,
called hdmi-forum vendor specific data block (HF-VSDB). This block
contains information about sink's support for HDMI 2.0 compliant
features. These features are:
    - Deep color YUV 420 support and BPC
    - 3D flags for
        - OSD Displarity
        - Dual view signaling
        - independent view signaling
    - SCDC support
    - Max TMDS char rate
    - Scrambling support

This patch adds a parser function for this block, and add flags to
indicate support for new features, in drm_display_info structure

V2:
- Addressed review comments from Thierry
	- remove len > 31 check
	- remove version check
	- fix duplicate values for macros of 36 and 30-bit depths
- Added a sub-class for HDMI related information within drm_display_info
  (Thierry, Daniel) and populated it with HF-VSDB specific info.

V3:
- Addressed review comments from Jose
	- check if SCDC supported while checking for scrambling
	- Fix the bit nos for YUV420 deep color macros
	- write HDMI_IEEE_OUI_HFVSDB value in lower case

Cc: Thierry Reding <treding at nvidia.com>
Cc: Daniel Vetter <daniel.vetter at intel.com>
Cc: Jose Abreu <joabreu at synopsys.com>
Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
---
 drivers/gpu/drm/drm_edid.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_edid.h     |  5 ++++
 include/linux/hdmi.h       |  1 +
 3 files changed, 76 insertions(+)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index b552197..f235576 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3224,6 +3224,23 @@ static int add_3d_struct_modes(struct drm_connector *connector, u16 structure,
 	return 0;
 }
 
+static bool cea_db_is_hf_vsdb(const u8 *db)
+{
+	u8 len;
+	int hfvsdb_id;
+
+	if (cea_db_tag(db) != VENDOR_BLOCK)
+		return false;
+
+	len = cea_db_payload_len(db);
+	if (len < 7)
+		return false;
+
+	hfvsdb_id = db[1] | (db[2] << 8) | (db[3] << 16);
+
+	return hfvsdb_id == HDMI_IEEE_OUI_HFVSDB;
+}
+
 static bool cea_db_is_hdmi_vsdb(const u8 *db)
 {
 	int hdmi_id;
@@ -3768,6 +3785,57 @@ bool drm_rgb_quant_range_selectable(struct edid *edid)
 }
 EXPORT_SYMBOL(drm_rgb_quant_range_selectable);
 
+static void drm_parse_yuv420_deep_color_info(struct drm_connector *connector,
+						const u8 *db)
+{
+	struct drm_hdmi_info *info = &connector->display_info.hdmi_info;
+
+	if (db[7] & DRM_EDID_YUV420_DC_48)
+		info->edid_yuv420_dc_modes |= DRM_EDID_YUV420_DC_48;
+	if (db[7] & DRM_EDID_YUV420_DC_36)
+		info->edid_yuv420_dc_modes |= DRM_EDID_YUV420_DC_36;
+	if (db[7] & DRM_EDID_YUV420_DC_30)
+		info->edid_yuv420_dc_modes |= DRM_EDID_YUV420_DC_30;
+
+	if (!info->edid_yuv420_dc_modes) {
+		DRM_DEBUG("%s: No YUV 420 deep color support in sink.\n",
+			  connector->name);
+		return;
+	}
+}
+
+static void
+drm_parse_hf_vsdb(struct drm_connector *connector, const u8 *db)
+{
+	struct drm_display_info *info = &connector->display_info;
+	struct drm_hdmi_info *hdmi_info = &info->hdmi_info;
+
+	if (db[5]) {
+		/*
+		 * If the sink supplies max tmds char rate in db,
+		 * the actual max tmds rate = db[5] * 5Mhz.
+		 */
+		info->max_tmds_clock = db[5] * 5000;
+		DRM_DEBUG_KMS("HF-VSDB: max TMDS clock %d kHz\n",
+		info->max_tmds_clock);
+	}
+
+	if (db[6] & DRM_HFVSDB_SCDC_SUPPORT)
+		hdmi_info->scdc_supported = true;
+	if (db[6] & DRM_HFVSDB_SCDC_RR_CAP)
+		hdmi_info->scdc_rr_cap = true;
+	if ((db[6] & DRM_HFVSDB_SCRAMBLING) && hdmi_info->scdc_supported)
+		hdmi_info->scrambling = true;
+	if (db[6] & DRM_HFVSDB_INDEPENDENT_VIEW)
+		hdmi_info->independent_view_3d = true;
+	if (db[6] & DRM_HFVSDB_DUAL_VIEW)
+		hdmi_info->dual_view_3d = true;
+	if (db[6] & DRM_HFVSDB_3D_OSD)
+		hdmi_info->osd_disparity_3d = true;
+
+	drm_parse_yuv420_deep_color_info(connector, db);
+}
+
 static void drm_parse_hdmi_deep_color_info(struct drm_connector *connector,
 					   const u8 *hdmi)
 {
@@ -3882,6 +3950,8 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
 
 		if (cea_db_is_hdmi_vsdb(db))
 			drm_parse_hdmi_vsdb_video(connector, db);
+		if (cea_db_is_hf_vsdb(db))
+			drm_parse_hf_vsdb(connector, db);
 	}
 }
 
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 38eabf6..a6453f7 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -212,6 +212,11 @@ struct detailed_timing {
 #define DRM_EDID_HDMI_DC_30               (1 << 4)
 #define DRM_EDID_HDMI_DC_Y444             (1 << 3)
 
+/* YUV 420 deep color modes */
+#define DRM_EDID_YUV420_DC_48		  (1 << 2)
+#define DRM_EDID_YUV420_DC_36		  (1 << 1)
+#define DRM_EDID_YUV420_DC_30		  (1 << 0)
+
 /* ELD Header Block */
 #define DRM_ELD_HEADER_BLOCK_SIZE	4
 
diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
index edbb4fc..3dd4e9a 100644
--- a/include/linux/hdmi.h
+++ b/include/linux/hdmi.h
@@ -35,6 +35,7 @@ enum hdmi_infoframe_type {
 };
 
 #define HDMI_IEEE_OUI 0x000c03
+#define HDMI_IEEE_OUI_HFVSDB 0xc45dd8
 #define HDMI_INFOFRAME_HEADER_SIZE  4
 #define HDMI_AVI_INFOFRAME_SIZE    13
 #define HDMI_SPD_INFOFRAME_SIZE    25
-- 
1.9.1