Commit 118362a9 authored by Chenyu Chen's avatar Chenyu Chen Committed by Alex Deucher
Browse files

drm/edid: Parse AMD Vendor-Specific Data Block 



Parse the AMD VSDB v3 from CTA extension blocks and store the result
in struct drm_amd_vsdb_info, a new field of drm_display_info. This
includes replay mode, panel type, and luminance ranges.

Signed-off-by: default avatarChenyu Chen <chen-yu.chen@amd.com>
Reviewed-by: default avatarMario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 57ce498f

drivers/gpu/drm/drm_edid.c

+72 −0
Original line number Diff line number Diff line
@@ -99,6 +99,29 @@ enum drm_edid_internal_quirk { 
};



#define MICROSOFT_IEEE_OUI	0xca125c

#define AMD_IEEE_OUI        0x00001A



#define AMD_VSDB_V3_PAYLOAD_MIN_LEN 15

#define AMD_VSDB_V3_PAYLOAD_MAX_LEN 20



struct amd_vsdb_v3_payload {

	u8 oui[3];

	u8 version;

	u8 feature_caps;

	u8 rsvd0[3];

	u8 cs_eotf_support;

	u8 lum1_max;

	u8 lum1_min;

	u8 lum2_max;

	u8 lum2_min;

	u8 rsvd1[2];

	/*

	 * Bytes beyond AMD_VSDB_V3_PAYLOAD_MIN_LEN are optional; a

	 * monitor may provide a payload as short as 15 bytes.  Always

	 * check cea_db_payload_len() before accessing extra[].

	 */

	u8 extra[AMD_VSDB_V3_PAYLOAD_MAX_LEN - AMD_VSDB_V3_PAYLOAD_MIN_LEN];

} __packed;



struct detailed_mode_closure {

	struct drm_connector *connector;
@@ -5205,6 +5228,13 @@ static bool cea_db_is_microsoft_vsdb(const struct cea_db *db) 
		cea_db_payload_len(db) == 21;

}



static bool cea_db_is_amd_vsdb(const struct cea_db *db)

{

	return cea_db_is_vendor(db, AMD_IEEE_OUI) &&

		cea_db_payload_len(db) >= AMD_VSDB_V3_PAYLOAD_MIN_LEN &&

		cea_db_payload_len(db) <= AMD_VSDB_V3_PAYLOAD_MAX_LEN;

}



static bool cea_db_is_vcdb(const struct cea_db *db)

{

	return cea_db_is_extended_tag(db, CTA_EXT_DB_VIDEO_CAP) &&
@@ -6401,6 +6431,45 @@ static void drm_parse_microsoft_vsdb(struct drm_connector *connector, 
		    connector->base.id, connector->name, version, db[5]);

}



static void drm_parse_amd_vsdb(struct drm_connector *connector,

			       const struct cea_db *db)

{

	struct drm_display_info *info = &connector->display_info;

	const u8 *data = cea_db_data(db);

	const struct amd_vsdb_v3_payload *p;



	p = (const struct amd_vsdb_v3_payload *)data;



	if (p->version != 0x03) {

		drm_dbg_kms(connector->dev,

			    "[CONNECTOR:%d:%s] Unsupported AMD VSDB version %u\n",

			    connector->base.id, connector->name, p->version);

		return;

	}



	info->amd_vsdb.version = p->version;

	info->amd_vsdb.replay_mode = p->feature_caps & 0x40;

	info->amd_vsdb.panel_type = (p->cs_eotf_support & 0xC0) >> 6;

	info->amd_vsdb.luminance_range1.max_luminance = p->lum1_max;

	info->amd_vsdb.luminance_range1.min_luminance = p->lum1_min;

	info->amd_vsdb.luminance_range2.max_luminance = p->lum2_max;

	info->amd_vsdb.luminance_range2.min_luminance = p->lum2_min;



	/*

	 * The AMD VSDB v3 payload length is variable (15..20 bytes).

	 * All fields through p->rsvd1 (byte 14) are always present,

	 * but p->extra[] (bytes 15+) may not be.  Any future access to

	 * extra[] must be guarded with a runtime length check to avoid

	 * out-of-bounds reads on shorter (but spec-valid) payloads.

	 * For example:

	 *

	 *   int len = cea_db_payload_len(db);

	 *

	 *   if (len > AMD_VSDB_V3_PAYLOAD_MIN_LEN)

	 *       info->amd_vsdb.foo = p->extra[0];

	 */

}



static void drm_parse_cea_ext(struct drm_connector *connector,

			      const struct drm_edid *drm_edid)

{
@@ -6449,6 +6518,8 @@ static void drm_parse_cea_ext(struct drm_connector *connector, 
			drm_parse_hdmi_forum_scds(connector, data);

		else if (cea_db_is_microsoft_vsdb(db))

			drm_parse_microsoft_vsdb(connector, data);

		else if (cea_db_is_amd_vsdb(db))

			drm_parse_amd_vsdb(connector, db);

		else if (cea_db_is_y420cmdb(db))

			parse_cta_y420cmdb(connector, db, &y420cmdb_map);

		else if (cea_db_is_y420vdb(db))
@@ -6641,6 +6712,7 @@ static void drm_reset_display_info(struct drm_connector *connector) 
	info->quirks = 0;



	info->source_physical_address = CEC_PHYS_ADDR_INVALID;

	memset(&info->amd_vsdb, 0, sizeof(info->amd_vsdb));

}



static void update_displayid_info(struct drm_connector *connector,

include/drm/drm_connector.h

+38 −0
Original line number Diff line number Diff line
@@ -693,6 +693,39 @@ enum drm_bus_flags { 
	DRM_BUS_FLAG_SHARP_SIGNALS = BIT(8),

};



/**

 * struct drm_amd_vsdb_info - AMD-specific VSDB information

 *

 * This structure holds information parsed from the AMD Vendor-Specific Data

 * Block (VSDB) version 3.

 */

struct drm_amd_vsdb_info {

	/**

	 * @version: Version of the Vendor-Specific Data Block (VSDB)

	 */

	u8 version;



	/**

	 * @replay_mode: Panel Replay supported

	 */

	bool replay_mode;



	/**

	 * @panel_type: Panel technology type

	 */

	u8 panel_type;



	/**

	 * @luminance_range1: Luminance for max back light

	 */

	struct drm_luminance_range_info luminance_range1;



	/**

	 * @luminance_range2: Luminance for min back light

	 */

	struct drm_luminance_range_info luminance_range2;

};



/**

 * struct drm_display_info - runtime data about the connected sink

 *
@@ -883,6 +916,11 @@ struct drm_display_info { 
	 * Defaults to CEC_PHYS_ADDR_INVALID (0xffff).

	 */

	u16 source_physical_address;



	/**

	 * @amd_vsdb: AMD-specific VSDB information.

	 */

	struct drm_amd_vsdb_info amd_vsdb;

};



int drm_display_info_set_bus_formats(struct drm_display_info *info,