On Tue, May 30, 2017 at 05:43:42PM +0530, Shashank Sharma wrote:
> HDMI 2.0 spec adds support for ycbcr420 sub-sampled output.
> CEA-861-F adds two new blocks in EDID, to provide information
> about sink's support for ycbcr420 output.
>
> One of these new blocks is: ycbcr420cmdb(ycbcr 420 capability
> map data block). This 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 2 means second video mode from svd
> list can support ycbcr420 output too, and so on.
>
> This patch adds parsing and handling of ycbcr420-cmdb in the DRM layer.
>
> 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.
>
> Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxxxx>
> ---
> drivers/gpu/drm/drm_edid.c | 118 ++++++++++++++++++++++++++++++++++++++++++--
> include/drm/drm_connector.h | 12 +++++
> 2 files changed, 127 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index c3fa3a1..ce86528 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 +3145,50 @@ drm_display_mode_from_vic_index(struct drm_connector *connector,
> return newmode;
> }
>
> +static void
> +drm_add_vcb_modes(struct drm_connector *connector, u8 vic)
> +{
> + u32 *map;
> + u8 index = 0;
> + 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. This indicates
> + * support for ycbcr420 output per VIC. Arrangement is bit[n] indicates
> + * if vic[n+1] supports ycbcr420 output.
> + * ycbcr420_vcb_modes[0] = |VIC=32 |VIC=31 |............|VIC=2 |VIC=1 |
> + * ycbcr420_vcb_modes[1] = |VIC=64 |VIC=63 |............|VIC=34|VIC=33|
> + * ycbcr420_vcb_modes[2] = |VIC=96 |VIC=95 |............|VIC=66|VIC=65|
> + * ycbcr420_vcb_modes[3] = |VIC=128|VIC=127|............|VIC=34|VIC=97|
> + */
> + map = &(hdmi->ycbcr420_vcb_modes[(vic - 1) / 32]);
> + index = (vic - 1) % 32;
> + *map |= (1 << index);
unsigned long whatever[BITS_TO_LONGS(nr)];
__set_bit(), test_bit(), etc.
> +}
> +
> 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;
> + u64 hdmi_vcb_map = hdmi->ycbcr420_vcb_map;
>
> 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 such CEA modes in VDB, which can
> + * support ycbcr420 sampling output also.
> + * For example, if the bit 0 in bitmap is set,
> + * first mode in VDB can support ycbcr420 output too.
> + */
> + if (hdmi_vcb_map & (1 << i))
> + drm_add_vcb_modes(connector, db[i]);
> drm_mode_probed_add(connector, mode);
> modes++;
> }
> @@ -3427,6 +3464,12 @@ 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 +3530,70 @@ static bool cea_db_is_hdmi_forum_vsdb(const u8 *db)
> return oui == HDMI_FORUM_IEEE_OUI;
> }
>
> +static bool cea_db_is_y420cmdb(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;
> +}
> +
> #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)
> {
> @@ -4196,6 +4300,8 @@ 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_y420cmdb(db))
> + drm_parse_y420cmdb_bitmap(connector, db);
> }
> }
>
> @@ -4430,6 +4536,13 @@ 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 +4563,13 @@ 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 2fe09c1..07b10ab 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -137,6 +137,17 @@ struct drm_scdc {
> struct drm_hdmi_info {
> /** @scdc: sink's scdc support and capabilities */
> struct drm_scdc scdc;
> +
> + /**
> + * @ycbcr420_vcb_modes: bitmap of modes which can support ycbcr420
> + * output also along with normal outputs. There are total 107 VICs
> + * defined by CEA-861-F spec, so the size is 128bits to map upto 128
> + * VICs;
> + */
> + u32 ycbcr420_vcb_modes[4];
> +
> + /** @ycbcr420_vcb_map: bitmap of SVD index, to extraxt vcb modes */
> + u64 ycbcr420_vcb_map;
> };
>
> /**
> @@ -200,6 +211,7 @@ 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
--
Ville Syrjälä
Intel OTC
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