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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: Shashank 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: Ville Syrjälä <ville.syrjala@linux.intel.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.