Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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: Chenyu Chen <chen-yu.chen@amd.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
authored by
Chenyu Chen
and committed by
Alex Deucher
118362a9
57ce498f
+110
+72
drivers/gpu/drm/drm_edid.c
+72
drivers/gpu/drm/drm_edid.c
···
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};
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#define MICROSOFT_IEEE_OUI 0xca125c
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#define AMD_IEEE_OUI 0x00001A
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#define AMD_VSDB_V3_PAYLOAD_MIN_LEN 15
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#define AMD_VSDB_V3_PAYLOAD_MAX_LEN 20
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struct amd_vsdb_v3_payload {
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u8 oui[3];
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u8 version;
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u8 feature_caps;
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u8 rsvd0[3];
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u8 cs_eotf_support;
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u8 lum1_max;
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u8 lum1_min;
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u8 lum2_max;
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u8 lum2_min;
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u8 rsvd1[2];
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/*
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* Bytes beyond AMD_VSDB_V3_PAYLOAD_MIN_LEN are optional; a
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* monitor may provide a payload as short as 15 bytes. Always
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* check cea_db_payload_len() before accessing extra[].
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*/
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u8 extra[AMD_VSDB_V3_PAYLOAD_MAX_LEN - AMD_VSDB_V3_PAYLOAD_MIN_LEN];
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} __packed;
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struct detailed_mode_closure {
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struct drm_connector *connector;
···
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cea_db_payload_len(db) == 21;
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}
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static bool cea_db_is_amd_vsdb(const struct cea_db *db)
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{
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return cea_db_is_vendor(db, AMD_IEEE_OUI) &&
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cea_db_payload_len(db) >= AMD_VSDB_V3_PAYLOAD_MIN_LEN &&
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cea_db_payload_len(db) <= AMD_VSDB_V3_PAYLOAD_MAX_LEN;
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}
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static bool cea_db_is_vcdb(const struct cea_db *db)
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{
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return cea_db_is_extended_tag(db, CTA_EXT_DB_VIDEO_CAP) &&
···
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connector->base.id, connector->name, version, db[5]);
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}
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static void drm_parse_amd_vsdb(struct drm_connector *connector,
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const struct cea_db *db)
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{
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struct drm_display_info *info = &connector->display_info;
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const u8 *data = cea_db_data(db);
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const struct amd_vsdb_v3_payload *p;
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p = (const struct amd_vsdb_v3_payload *)data;
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if (p->version != 0x03) {
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drm_dbg_kms(connector->dev,
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"[CONNECTOR:%d:%s] Unsupported AMD VSDB version %u\n",
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connector->base.id, connector->name, p->version);
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return;
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}
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info->amd_vsdb.version = p->version;
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info->amd_vsdb.replay_mode = p->feature_caps & 0x40;
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info->amd_vsdb.panel_type = (p->cs_eotf_support & 0xC0) >> 6;
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info->amd_vsdb.luminance_range1.max_luminance = p->lum1_max;
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info->amd_vsdb.luminance_range1.min_luminance = p->lum1_min;
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info->amd_vsdb.luminance_range2.max_luminance = p->lum2_max;
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info->amd_vsdb.luminance_range2.min_luminance = p->lum2_min;
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/*
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* The AMD VSDB v3 payload length is variable (15..20 bytes).
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* All fields through p->rsvd1 (byte 14) are always present,
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* but p->extra[] (bytes 15+) may not be. Any future access to
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* extra[] must be guarded with a runtime length check to avoid
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* out-of-bounds reads on shorter (but spec-valid) payloads.
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* For example:
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*
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* int len = cea_db_payload_len(db);
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*
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* if (len > AMD_VSDB_V3_PAYLOAD_MIN_LEN)
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* info->amd_vsdb.foo = p->extra[0];
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*/
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}
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static void drm_parse_cea_ext(struct drm_connector *connector,
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const struct drm_edid *drm_edid)
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{
···
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drm_parse_hdmi_forum_scds(connector, data);
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else if (cea_db_is_microsoft_vsdb(db))
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drm_parse_microsoft_vsdb(connector, data);
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else if (cea_db_is_amd_vsdb(db))
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drm_parse_amd_vsdb(connector, db);
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else if (cea_db_is_y420cmdb(db))
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parse_cta_y420cmdb(connector, db, &y420cmdb_map);
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else if (cea_db_is_y420vdb(db))
···
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info->quirks = 0;
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info->source_physical_address = CEC_PHYS_ADDR_INVALID;
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memset(&info->amd_vsdb, 0, sizeof(info->amd_vsdb));
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}
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static void update_displayid_info(struct drm_connector *connector,
+38
include/drm/drm_connector.h
+38
include/drm/drm_connector.h
···
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};
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/**
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* struct drm_amd_vsdb_info - AMD-specific VSDB information
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*
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* This structure holds information parsed from the AMD Vendor-Specific Data
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* Block (VSDB) version 3.
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*/
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struct drm_amd_vsdb_info {
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/**
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* @version: Version of the Vendor-Specific Data Block (VSDB)
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*/
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u8 version;
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/**
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* @replay_mode: Panel Replay supported
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*/
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bool replay_mode;
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/**
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* @panel_type: Panel technology type
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*/
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u8 panel_type;
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/**
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* @luminance_range1: Luminance for max back light
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*/
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struct drm_luminance_range_info luminance_range1;
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/**
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* @luminance_range2: Luminance for min back light
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*/
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struct drm_luminance_range_info luminance_range2;
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};
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/**
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* struct drm_display_info - runtime data about the connected sink
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*
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* Describes a given display (e.g. CRT or flat panel) and its limitations. For
···
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* Defaults to CEC_PHYS_ADDR_INVALID (0xffff).
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*/
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u16 source_physical_address;
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/**
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* @amd_vsdb: AMD-specific VSDB information.
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*/
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struct drm_amd_vsdb_info amd_vsdb;
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};
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int drm_display_info_set_bus_formats(struct drm_display_info *info,