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raspberrypi
drm: Add DRM_MODE_TV_MODE_MONOCHROME
Add this as a value for enum_drm_connector_tv_mode, represented by the string "MONOCHROME", to represent video with standard timings but no colour encoding or bursts. Define it to have no pedestal (since only NTSC-M calls for a pedestal).
Change default mode creation to acommodate the new tv_mode value which comprises both 525-line and 625-line formats.
It's a draft for now as I'm not sure if it's something we want to commit ourselves to, or eventually upstream?
Hopefully I have mentioned the new tv_mode in all the places where it's needed?
Carefully worded to imply that it supports both 525-line and 625-line formats but is not necessarily limited to those two.
- It might be vaguely useful in its own right;
- It also solves my problem of how to hide/advertise "vintage" TV modes in RP1 VEC;
- It does not solve the problem of more generic custom modes in the console FB.
I'm still a bit wary of merging it. Once the VEC driver (either of them) starts referring to this, they will be impossible to upstream without this change (or without reverting support for it).
A late thought: Now I think "Mono" should be not all upper-case, since it's not an acronym.
That would be more in keeping with the other property names in drm_connector.c.
I hope the abbreviation from "Monochrome" will be acceptable.
I'll create a patch to implement mono on vc4_vec and try upstreaming it. I'll query the ambiguity over having resolutions quoted in the descriptions but then omitting PAL60.
This branch and PR are somewhat orphaned now, but for completeness I've pushed an implementation for RP1 VEC.