[PATCH v2 2/2] drm: parse hf-vsdb

Shashank Sharma
2016-12-20T13:47:30Z

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.

Cc: Thierry Reding <treding@nvidia.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Shashank Sharma <shashank.sharma@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..59e04fb 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->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..df606e3 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 << 6)
+#define DRM_EDID_YUV420_DC_36 (1 << 5)
+#define DRM_EDID_YUV420_DC_30 (1 << 4)
+
/* ELD Header Block */
#define DRM_ELD_HEADER_BLOCK_SIZE 4

diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
index edbb4fc..2d4e9ef 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