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Commit 832d4f2f authored by Shashank Sharma's avatar Shashank Sharma Committed by Ville Syrjälä
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drm/edid: parse YCBCR420 videomodes from EDID 



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@linux.intel.com>
Cc: Jose Abreu <joabreu@synopsys.com>
Cc: Emil Velikov <emil.l.velikov@gmail.com>

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.

V4: Addressed review comments from Ville:
    - s/ycbcr_420_vdb/y420vdb
    - s/ycbcr_420_vcb/y420cmdb
    - Be less verbose on description of do_y420vdb_modes
    - Move newmode variable in the loop scope.
    - Use svd_to_vic() to get a VIC, instead of 0x7f
    - Remove bitmap description for CMDB modes & VDB modes
    - Dont add connector->ycbcr_420_allowed check for cmdb modes
    - Remove 'len' variable, in is_y420cmdb function, which is used
      only once
    - Add length check in is_y420vdb function
    - Remove unnecessary if (!db) check in function parse_y420cmdb_bitmap
    - Do not add print about YCBCR 420 modes
    - Fix indentation in few places
    - Move ycbcr420_dc_modes in next patch, where its used
    - Add a separate patch for movement of drm_add_display_info()

V5: Addressed review comments from Ville:
    - Add the patch which cleans up the current EXTENDED_TAG usage
    - Make y420_cmdb_map u64
    - Do not block ycbcr420 modes while parsing the EDID, rather
      add a separate helper function to prune ycbcr420-only modes from
      connector's probed modes.

V6: Rebase
V7: Move this patch after the 420_only validation patch (Ville)
V8: Addressed review comments from Ville
    - use cea_vic_valid check before adding cmdb/vdb modes
    - add check for i < 64 while adding cmdb modes
    - use 1ULL while checking bitmap

Signed-off-by: default avatarShashank Sharma <shashank.sharma@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1500028426-14883-1-git-send-email-shashank.sharma@intel.com


[vsyrjala: Fix checkpatch complaints and indentation]
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
parent d8523153

drivers/gpu/drm/drm_edid.c

+150 −2
Original line number Diff line number Diff line
@@ -2783,6 +2783,8 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid, 
#define SPEAKER_BLOCK	0x04

#define USE_EXTENDED_TAG 0x07

#define EXT_VIDEO_CAPABILITY_BLOCK 0x00

#define EXT_VIDEO_DATA_BLOCK_420	0x0E

#define EXT_VIDEO_CAP_BLOCK_Y420CMDB 0x0F

#define EDID_BASIC_AUDIO	(1 << 6)

#define EDID_CEA_YCRCB444	(1 << 5)

#define EDID_CEA_YCRCB422	(1 << 4)
@@ -3153,15 +3155,85 @@ drm_display_mode_from_vic_index(struct drm_connector *connector, 
	return newmode;

}



/*

 * do_y420vdb_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

 *

 * Parse the CEA-861-F YCBCR 420 Video Data Block (Y420VDB)

 * which contains modes which can be supported in YCBCR 420

 * output format only.

 */

static int do_y420vdb_modes(struct drm_connector *connector,

			    const u8 *svds, u8 svds_len)

{

	int modes = 0, i;

	struct drm_device *dev = connector->dev;

	struct drm_display_info *info = &connector->display_info;

	struct drm_hdmi_info *hdmi = &info->hdmi;



	for (i = 0; i < svds_len; i++) {

		u8 vic = svd_to_vic(svds[i]);

		struct drm_display_mode *newmode;



		if (!drm_valid_cea_vic(vic))

			continue;



		newmode = drm_mode_duplicate(dev, &edid_cea_modes[vic]);

		if (!newmode)

			break;

		bitmap_set(hdmi->y420_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_cmdb_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_cmdb_modes(struct drm_connector *connector, u8 svd)

{

	u8 vic = svd_to_vic(svd);

	struct drm_hdmi_info *hdmi = &connector->display_info.hdmi;



	if (!drm_valid_cea_vic(vic))

		return;



	bitmap_set(hdmi->y420_cmdb_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 (i < 64 && hdmi->y420_cmdb_map & (1ULL << i))

				drm_add_cmdb_modes(connector, db[i]);



			drm_mode_probed_add(connector, mode);

			modes++;

		}
@@ -3503,9 +3575,77 @@ 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)

{

	if (cea_db_tag(db) != USE_EXTENDED_TAG)

		return false;



	if (!cea_db_payload_len(db))

		return false;



	if (cea_db_extended_tag(db) != EXT_VIDEO_CAP_BLOCK_Y420CMDB)

		return false;



	return true;

}



static bool cea_db_is_y420vdb(const u8 *db)

{

	if (cea_db_tag(db) != USE_EXTENDED_TAG)

		return false;



	if (!cea_db_payload_len(db))

		return false;



	if (cea_db_extended_tag(db) != EXT_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 (map_len == 0) {

		/* All CEA modes support ycbcr420 sampling also.*/

		hdmi->y420_cmdb_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)

		info->color_formats |= DRM_COLOR_FORMAT_YCRCB420;



	hdmi->y420_cmdb_map = map;

}



static int

add_cea_modes(struct drm_connector *connector, struct edid *edid)

{
@@ -3528,10 +3668,16 @@ 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_y420vdb(db)) {

				const u8 *vdb420 = &db[2];



				/* Add 4:2:0(only) modes present in EDID */

				modes += do_y420vdb_modes(connector,

							  vdb420,

							  dbl - 1);

			}

		}

	}
@@ -4214,6 +4360,8 @@ 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);

	}

}

include/drm/drm_connector.h

+12 −0
Original line number Diff line number Diff line
@@ -143,6 +143,17 @@ struct drm_hdmi_info { 
	 * upto 128 VICs;

	 */

	unsigned long y420_vdb_modes[BITS_TO_LONGS(128)];



	/**

	 * @y420_cmdb_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 y420_cmdb_modes[BITS_TO_LONGS(128)];



	/** @y420_cmdb_map: bitmap of SVD index, to extraxt vcb modes */

	u64 y420_cmdb_map;

};



/**
@@ -206,6 +217,7 @@ 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