HDMI 2.0 spec adds support for YCBCR420 sub-sampled output.
CEA-861-F adds two new blocks in EDID's CEA extension blocks,
to provide information about sink's YCBCR420 output capabilities.
These blocks are:
- YCBCR420vdb(YCBCR 420 video data block):
This block contains VICs of video modes, which can be sopported only
in YCBCR420 output mode (Not in RGB/YCBCR444/422. Its like a normal
SVD block, valid for YCBCR420 modes only.
- YCBCR420cmdb(YCBCR 420 capability map data block):
This block gives information about video modes which can support
YCBCR420 output mode also (along with RGB,YCBCR444/422 etc) This
block contains a bitmap index of normal svd videomodes, which can
support YCBCR420 output too.
So if bit 0 from first vcb byte is set, first video mode in the svd
list can support YCBCR420 output too. Bit 1 means second video mode
from svd list can support YCBCR420 output too, and so on.
This patch adds two bitmaps in display's hdmi_info structure, one each
for VCB and VDB modes. If the source is HDMI 2.0 capable, this patch
adds:
- VDB modes (YCBCR 420 only modes) in connector's mode list, also makes
an entry in the vdb_bitmap per vic.
- VCB modes (YCBCR 420 also modes) only entry in the vcb_bitmap.
Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: Jose Abreu <joabreu@xxxxxxxxxxxx>
Cc: Emil Velikov <emil.l.velikov@xxxxxxxxx>
V2: Addressed
Review comments from Emil:
- Use 1ULL<<i instead of 1<<i to make sure the output is 64bit.
- Use the suggested method for updating dbmap.
- Add documentation for YCBCR420_vcb_map to fix kbuild warning.
Review comments from Ville:
- Do not expose the YCBCR420 flags in uabi layer, keep it internal.
- Save a map of YCBCR420 modes for future reference.
- Check db length before trying to parse extended tag.
- Add a warning if there are > 64 modes in capability map block.
- Use y420cmdb in function names and macros while dealing with vcb
to be aligned with spec.
- Move the display information parsing block ahead of mode parsing
blocks.
V3: Addressed design/review comments from Ville
- Do not add flags in video modes, else we have to expose them to user
- There should not be a UABI change, and kernel should detect the
choice of the output based on type of mode, and the bitmaps.
- Use standard bitops from kernel bitmap header, instead of calculating
bit positions manually.
Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxxxx>
---
drivers/gpu/drm/drm_edid.c | 193 ++++++++++++++++++++++++++++++++++++++++++--
include/drm/drm_connector.h | 23 ++++++
2 files changed, 211 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 6fd8a98..4953f87 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2781,7 +2781,9 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
#define VIDEO_BLOCK 0x02
#define VENDOR_BLOCK 0x03
#define SPEAKER_BLOCK 0x04
-#define VIDEO_CAPABILITY_BLOCK 0x07
+#define VIDEO_CAPABILITY_BLOCK 0x07
+#define VIDEO_DATA_BLOCK_420 0x0E
+#define VIDEO_CAP_BLOCK_Y420CMDB 0x0F
#define EDID_BASIC_AUDIO (1 << 6)
#define EDID_CEA_YCRCB444 (1 << 5)
#define EDID_CEA_YCRCB422 (1 << 4)
@@ -3143,15 +3145,103 @@ drm_display_mode_from_vic_index(struct drm_connector *connector,
return newmode;
}
+/*
+ * do_ycbcr_420_vdb_modes - Parse YCBCR 420 only modes
+ * @connector: connector corresponding to the HDMI sink
+ * @svds: start of the data block of CEA YCBCR 420 VDB
+ * @len: length of the CEA YCBCR 420 VDB
+ *
+ * CEA-861-F has added a new video block called YCBCR 420 Video
+ * Data Block (ycbcr 420 vdb). This block contains modes which
+ * support YCBCR 420 HDMI output (only YCBCR 420). This function
+ * parses the block and adds these modes into connector's mode list.
+ */
+static int do_ycbcr_420_vdb_modes(struct drm_connector *connector,
+ const u8 *svds, u8 svds_len)
+{
+ int modes = 0, i;
+ struct drm_device *dev = connector->dev;
+ struct drm_display_mode *newmode;
+ struct drm_display_info *info = &connector->display_info;
+ struct drm_hdmi_info *hdmi = &info->hdmi;
+
+ for (i = 0; i < svds_len; i++) {
+ u8 vic = svds[i] & 0x7f;
+
+ newmode = drm_mode_duplicate(dev, &edid_cea_modes[vic]);
+ if (!newmode)
+ break;
+ /*
+ * ycbcr420_vdb_modes is a fix position 128 bit bitmap.
+ * Every bit here represents a VIC, from CEA-861-F list.
+ * So if bit[n] is set, it indicates vic[n+1] supports
+ * YCBCR420 output. Bit 0 is dummy, as VICs start at 1.
+ * ycbcr420_vcb_modes[0] = |VIC=64 |VIC=63 |.....|VIC=2 |VIC=1 |
+ * ycbcr420_vcb_modes[1] = |VIC=128|VIC=127|.....|VIC=66|VIC=65|
+ */
+ bitmap_set(hdmi->ycbcr420_vdb_modes, vic, 1);
+ drm_mode_probed_add(connector, newmode);
+ modes++;
+ }
+
+ if (modes > 0)
+ info->color_formats |= DRM_COLOR_FORMAT_YCRCB420;
+ return modes;
+}
+
+/*
+ * drm_add_vcb_modes - Add a YCBCR 420 mode into bitmap
+ * @connector: connector corresponding to the HDMI sink
+ * @vic: CEA vic for the video mode to be added in the map
+ *
+ * Makes an entry for a videomode in the YCBCR 420 bitmap
+ */
+static void
+drm_add_vcb_modes(struct drm_connector *connector, u8 vic)
+{
+ struct drm_hdmi_info *hdmi = &connector->display_info.hdmi;
+
+ /* VICs are 1 to 127(107 defined till CEA-861-F) */
+ vic &= 127;
+
+ /*
+ * ycbcr420_vcb_modes is a fix position 128 bit bitmap.
+ * Every bit here represents a VIC, from CEA-861-F list.
+ * So if bit[n] is set, it indicates vic[n+1] supports
+ * YCBCR420 output. Bit 0 is dummy, as VICs start at 1.
+ * ycbcr420_vcb_modes[0] = |VIC=64 |VIC=63 |.....|VIC=2 |VIC=1 |
+ * ycbcr420_vcb_modes[1] = |VIC=128|VIC=127|.....|VIC=66|VIC=65|
+ * Difference between a vcb_mode and vdb_mode is that a vcb_mode
+ * can support other HDMI outputs like RGB/YCBCR444/422 also
+ * along with YCBCR 240, whereas a vdb_mode can only support YCBCR
+ * 420 HDMI output.
+ */
+ bitmap_set(hdmi->ycbcr420_vcb_modes, vic, 1);
+}
+
static int
do_cea_modes(struct drm_connector *connector, const u8 *db, u8 len)
{
int i, modes = 0;
+ struct drm_hdmi_info *hdmi = &connector->display_info.hdmi;
for (i = 0; i < len; i++) {
struct drm_display_mode *mode;
mode = drm_display_mode_from_vic_index(connector, db, len, i);
if (mode) {
+ /*
+ * YCBCR420 capability block contains a bitmap which
+ * gives the index of CEA modes from CEA VDB, which
+ * can support YCBCR 420 sampling output also (apart
+ * from RGB/YCBCR444 etc).
+ * For example, if the bit 0 in bitmap is set,
+ * first mode in VDB can support YCBCR420 output too.
+ * Add YCBCR420 modes only if sink is HDMI 2.0 capable.
+ */
+ if (connector->is_hdmi2_src &&
+ test_bit(i, &hdmi->ycbcr420_vcb_map))
+ drm_add_vcb_modes(connector, db[i]);
+
drm_mode_probed_add(connector, mode);
modes++;
}
@@ -3427,6 +3517,12 @@ do_hdmi_vsdb_modes(struct drm_connector *connector, const u8 *db, u8 len,
}
static int
+cea_db_extended_tag(const u8 *db)
+{
+ return db[1];
+}
+
+static int
cea_db_payload_len(const u8 *db)
{
return db[0] & 0x1f;
@@ -3487,9 +3583,81 @@ static bool cea_db_is_hdmi_forum_vsdb(const u8 *db)
return oui == HDMI_FORUM_IEEE_OUI;
}
+static bool cea_db_is_ycbcr_420_cmdb(const u8 *db)
+{
+ u8 len = cea_db_payload_len(db);
+
+ if (cea_db_tag(db) != VIDEO_CAPABILITY_BLOCK)
+ return false;
+
+ if (!len)
+ return false;
+
+ if (cea_db_extended_tag(db) != VIDEO_CAP_BLOCK_Y420CMDB)
+ return false;
+
+ return true;
+}
+
+static bool cea_db_is_ycbcr_420_vdb(const u8 *db)
+{
+ if (cea_db_tag(db) != VIDEO_CAPABILITY_BLOCK)
+ return false;
+
+ if (cea_db_extended_tag(db) != VIDEO_DATA_BLOCK_420)
+ return false;
+
+ return true;
+}
+
#define for_each_cea_db(cea, i, start, end) \
for ((i) = (start); (i) < (end) && (i) + cea_db_payload_len(&(cea)[(i)]) < (end); (i) += cea_db_payload_len(&(cea)[(i)]) + 1)
+static void drm_parse_y420cmdb_bitmap(struct drm_connector *connector,
+ const u8 *db)
+{
+ struct drm_display_info *info = &connector->display_info;
+ struct drm_hdmi_info *hdmi = &info->hdmi;
+ u8 map_len = cea_db_payload_len(db) - 1;
+ u8 count;
+ u64 map = 0;
+
+ if (!db)
+ return;
+
+ if (map_len == 0) {
+ /* All CEA modes support ycbcr420 sampling also.*/
+ hdmi->ycbcr420_vcb_map = U64_MAX;
+ info->color_formats |= DRM_COLOR_FORMAT_YCRCB420;
+ return;
+ }
+
+ /*
+ * This map indicates which of the existing CEA block modes
+ * from VDB can support YCBCR420 output too. So if bit=0 is
+ * set, first mode from VDB can support YCBCR420 output too.
+ * We will parse and keep this map, before parsing VDB itself
+ * to avoid going through the same block again and again.
+ *
+ * Spec is not clear about max possible size of this block.
+ * Clamping max bitmap block size at 8 bytes. Every byte can
+ * address 8 CEA modes, in this way this map can address
+ * 8*8 = first 64 SVDs.
+ */
+ if (WARN_ON_ONCE(map_len > 8))
+ map_len = 8;
+
+ for (count = 0; count < map_len; count++)
+ map |= (u64)db[2 + count] << (8 * count);
+
+ if (map) {
+ DRM_DEBUG_KMS("Sink supports ycbcr 420\n");
+ info->color_formats |= DRM_COLOR_FORMAT_YCRCB420;
+ }
+
+ hdmi->ycbcr420_vcb_map = map;
+}
+
static int
add_cea_modes(struct drm_connector *connector, struct edid *edid)
{
@@ -3512,10 +3680,17 @@ add_cea_modes(struct drm_connector *connector, struct edid *edid)
video = db + 1;
video_len = dbl;
modes += do_cea_modes(connector, video, dbl);
- }
- else if (cea_db_is_hdmi_vsdb(db)) {
+ } else if (cea_db_is_hdmi_vsdb(db)) {
hdmi = db;
hdmi_len = dbl;
+ } else if (cea_db_is_ycbcr_420_vdb(db) &&
+ connector->is_hdmi2_src) {
+ const u8 *vdb420 = &db[2];
+
+ /* Add 4:2:0(only) modes present in EDID */
+ modes += do_ycbcr_420_vdb_modes(connector,
+ vdb420,
+ dbl - 1);
}
}
}
@@ -4196,6 +4371,8 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
drm_parse_hdmi_vsdb_video(connector, db);
if (cea_db_is_hdmi_forum_vsdb(db))
drm_parse_hdmi_forum_vsdb(connector, db);
+ if (cea_db_is_ycbcr_420_cmdb(db))
+ drm_parse_y420cmdb_bitmap(connector, db);
}
}
@@ -4430,6 +4607,13 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
quirks = edid_get_quirks(edid);
/*
+ * CEA-861-F adds ycbcr capability map block, for HDMI 2.0 sinks.
+ * To avoid multiple parsing of same block, lets get the sink info
+ * before parsing CEA modes.
+ */
+ drm_add_display_info(connector, edid);
+
+ /*
* EDID spec says modes should be preferred in this order:
* - preferred detailed mode
* - other detailed modes from base block
@@ -4450,14 +4634,13 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
num_modes += add_cea_modes(connector, edid);
num_modes += add_alternate_cea_modes(connector, edid);
num_modes += add_displayid_detailed_modes(connector, edid);
+
if (edid->features & DRM_EDID_FEATURE_DEFAULT_GTF)
num_modes += add_inferred_modes(connector, edid);
if (quirks & (EDID_QUIRK_PREFER_LARGE_60 | EDID_QUIRK_PREFER_LARGE_75))
edid_fixup_preferred(connector, quirks);
- drm_add_display_info(connector, edid);
-
if (quirks & EDID_QUIRK_FORCE_6BPC)
connector->display_info.bpc = 6;
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 390319c..5a47c33 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -137,6 +137,28 @@ struct drm_scdc {
struct drm_hdmi_info {
/** @scdc: sink's scdc support and capabilities */
struct drm_scdc scdc;
+
+ /**
+ * @ycbcr420_vdb_modes: bitmap of modes which can support ycbcr420
+ * output only (not normal RGB/YCBCR444/422 outputs). There are total
+ * 107 VICs defined by CEA-861-F spec, so the size is 128 bits to map
+ * upto 128 VICs;
+ */
+ unsigned long ycbcr420_vdb_modes[BITS_TO_LONGS(128)];
+
+ /**
+ * @ycbcr420_vcb_modes: bitmap of modes which can support ycbcr420
+ * output also, along with normal HDMI outputs. There are total 107
+ * VICs defined by CEA-861-F spec, so the size is 128 bits to map upto
+ * 128 VICs;
+ */
+ unsigned long ycbcr420_vcb_modes[BITS_TO_LONGS(128)];
+
+ /** @ycbcr420_vcb_map: bitmap of SVD index, to extraxt vcb modes */
+ unsigned long ycbcr420_vcb_map;
+
+ /** @ycbcr420_dc_modes: bitmap of deep color support index */
+ u8 ycbcr420_dc_modes;
};
/**
@@ -200,6 +222,7 @@ struct drm_display_info {
#define DRM_COLOR_FORMAT_RGB444 (1<<0)
#define DRM_COLOR_FORMAT_YCRCB444 (1<<1)
#define DRM_COLOR_FORMAT_YCRCB422 (1<<2)
+#define DRM_COLOR_FORMAT_YCRCB420 (1<<3)
/**
* @color_formats: HDMI Color formats, selects between RGB and YCrCb
--
2.7.4
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