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: Chenyu Chen <[email protected]> --- drivers/gpu/drm/drm_edid.c | 72 +++++++++++++++++++++++++++++++++++++ include/drm/drm_connector.h | 38 ++++++++++++++++++++ 2 files changed, 110 insertions(+) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 26bb7710a462..76280e6e1892 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -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, diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h index c18be8c19de0..c398dbc68bbc 100644 --- a/include/drm/drm_connector.h +++ b/include/drm/drm_connector.h @@ -667,6 +667,39 @@ 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 * @@ -861,6 +894,11 @@ 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, -- 2.43.0
