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Commit d0c94692 authored by Mario Kleiner's avatar Mario Kleiner Committed by Alex Deucher
Browse files

drm/edid: Parse and handle HDMI deep color modes. 



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: default avatarMario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 89b92339

drivers/gpu/drm/drm_edid.c

+108 −2
Original line number Diff line number Diff line
@@ -3422,17 +3422,117 @@ 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;
@@ -3462,6 +3562,9 @@ 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;
@@ -3491,6 +3594,9 @@ 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;
@@ -3549,7 +3655,7 @@ 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;

include/drm/drm_edid.h

+5 −0
Original line number Diff line number Diff line
@@ -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 */