[PATCH 5/5] drm/edid: Parse and handle HDMI deep color modes.
Alex Deucher
alexdeucher at gmail.com
Tue May 20 16:17:51 PDT 2014
From: Mario Kleiner <mario.kleiner.de at gmail.com>
Check the HDMI cea block for deep color mode bits. If available,
assign the highest supported bpc for a hdmi display, corresponding
to the given deep color modes.
Signed-off-by: Mario Kleiner <mario.kleiner.de at gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
drivers/gpu/drm/drm_edid.c | 110 ++++++++++++++++++++++++++++++++++++++++++++-
include/drm/drm_edid.h | 5 +++
2 files changed, 113 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 7a4fd2e..c63f305 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3424,16 +3424,116 @@ bool drm_rgb_quant_range_selectable(struct edid *edid)
EXPORT_SYMBOL(drm_rgb_quant_range_selectable);
/**
+ * drm_assign_hdmi_deep_color_info - detect whether monitor supports
+ * hdmi deep color modes and update drm_display_info if so.
+ *
+ * @edid: monitor EDID information
+ * @info: Updated with maximum supported deep color bpc and color format
+ * if deep color supported.
+ *
+ * Parse the CEA extension according to CEA-861-B.
+ * Return true if HDMI deep color supported, false if not or unknown.
+ */
+static bool drm_assign_hdmi_deep_color_info(struct edid *edid,
+ struct drm_display_info *info,
+ struct drm_connector *connector)
+{
+ u8 *edid_ext, *hdmi;
+ int i;
+ int start_offset, end_offset;
+ unsigned int dc_bpc = 0;
+
+ edid_ext = drm_find_cea_extension(edid);
+ if (!edid_ext)
+ return false;
+
+ if (cea_db_offsets(edid_ext, &start_offset, &end_offset))
+ return false;
+
+ /*
+ * Because HDMI identifier is in Vendor Specific Block,
+ * search it from all data blocks of CEA extension.
+ */
+ for_each_cea_db(edid_ext, i, start_offset, end_offset) {
+ if (cea_db_is_hdmi_vsdb(&edid_ext[i])) {
+ /* HDMI supports at least 8 bpc */
+ info->bpc = 8;
+
+ hdmi = &edid_ext[i];
+ if (cea_db_payload_len(hdmi) < 6)
+ return false;
+
+ if (hdmi[6] & DRM_EDID_HDMI_DC_30) {
+ dc_bpc = 10;
+ DRM_DEBUG("%s: HDMI sink does deep color 30.\n",
+ drm_get_connector_name(connector));
+ }
+
+ if (hdmi[6] & DRM_EDID_HDMI_DC_36) {
+ dc_bpc = 12;
+ DRM_DEBUG("%s: HDMI sink does deep color 36.\n",
+ drm_get_connector_name(connector));
+ }
+
+ if (hdmi[6] & DRM_EDID_HDMI_DC_48) {
+ dc_bpc = 16;
+ DRM_DEBUG("%s: HDMI sink does deep color 48.\n",
+ drm_get_connector_name(connector));
+ }
+
+ if (dc_bpc > 0) {
+ DRM_DEBUG("%s: Assigning HDMI sink color depth as %d bpc.\n",
+ drm_get_connector_name(connector), dc_bpc);
+ info->bpc = dc_bpc;
+
+ /*
+ * Deep color support mandates RGB444 support for all video
+ * modes and forbids YCRCB422 support for all video modes per
+ * HDMI 1.3 spec.
+ */
+ info->color_formats = DRM_COLOR_FORMAT_RGB444;
+
+ /* YCRCB444 is optional according to spec. */
+ if (hdmi[6] & DRM_EDID_HDMI_DC_Y444) {
+ info->color_formats |= DRM_COLOR_FORMAT_YCRCB444;
+ DRM_DEBUG("%s: HDMI sink does YCRCB444 in deep color.\n",
+ drm_get_connector_name(connector));
+ }
+
+ /*
+ * Spec says that if any deep color mode is supported at all,
+ * then deep color 36 bit must be supported.
+ */
+ if (!(hdmi[6] & DRM_EDID_HDMI_DC_36)) {
+ DRM_DEBUG("%s: HDMI sink should do DC_36, but does not!\n",
+ drm_get_connector_name(connector));
+ }
+
+ return true;
+ }
+ else {
+ DRM_DEBUG("%s: No deep color support on this HDMI sink.\n",
+ drm_get_connector_name(connector));
+ }
+ }
+ }
+
+ return false;
+}
+
+/**
* drm_add_display_info - pull display info out if present
* @edid: EDID data
* @info: display info (attached to connector)
+ * @connector: connector whose edid is used to build display info
*
* Grab any available display info and stuff it into the drm_display_info
* structure that's part of the connector. Useful for tracking bpp and
* color spaces.
*/
static void drm_add_display_info(struct edid *edid,
- struct drm_display_info *info)
+ struct drm_display_info *info,
+ struct drm_connector *connector)
{
u8 *edid_ext;
@@ -3463,6 +3563,9 @@ static void drm_add_display_info(struct edid *edid,
info->color_formats |= DRM_COLOR_FORMAT_YCRCB422;
}
+ /* HDMI deep color modes supported? Assign to info, if so */
+ drm_assign_hdmi_deep_color_info(edid, info, connector);
+
/* Only defined for 1.4 with digital displays */
if (edid->revision < 4)
return;
@@ -3492,6 +3595,9 @@ static void drm_add_display_info(struct edid *edid,
break;
}
+ DRM_DEBUG("%s: Assigning EDID-1.4 digital sink color depth as %d bpc.\n",
+ drm_get_connector_name(connector), info->bpc);
+
info->color_formats |= DRM_COLOR_FORMAT_RGB444;
if (edid->features & DRM_EDID_FEATURE_RGB_YCRCB444)
info->color_formats |= DRM_COLOR_FORMAT_YCRCB444;
@@ -3550,7 +3656,7 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
if (quirks & (EDID_QUIRK_PREFER_LARGE_60 | EDID_QUIRK_PREFER_LARGE_75))
edid_fixup_preferred(connector, quirks);
- drm_add_display_info(edid, &connector->display_info);
+ drm_add_display_info(edid, &connector->display_info, connector);
if (quirks & EDID_QUIRK_FORCE_8BPC)
connector->display_info.bpc = 8;
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index a1441c5..b96031d 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -202,6 +202,11 @@ struct detailed_timing {
#define DRM_EDID_FEATURE_PM_SUSPEND (1 << 6)
#define DRM_EDID_FEATURE_PM_STANDBY (1 << 7)
+#define DRM_EDID_HDMI_DC_48 (1 << 6)
+#define DRM_EDID_HDMI_DC_36 (1 << 5)
+#define DRM_EDID_HDMI_DC_30 (1 << 4)
+#define DRM_EDID_HDMI_DC_Y444 (1 << 3)
+
struct edid {
u8 header[8];
/* Vendor & product info */
--
1.8.3.1
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