linux/Documentation/DocBook/gpu.tmpl, branch v4.5

apple-gmux: Add initial documentation

2016-01-11T14:56:23Z

Document what I've learned so far about the gmux so that we can collaboratively reverse-engineer its remaining unknown bits without everyone having to start from scratch. The DOC sections are bound together in the gpu.tmpl DocBook under a new vga_switcheroo "Handlers" chapter. Eventually this should be amended with documentation about the four other handlers that exist so far (nouveau v1 DSM, nouveau Optimus DSM, radeon ATPX, amdgpu ATPX). Requires kernel-doc with asciidoc support. The EFI variable was reverse-engineered by Bruno Bierbaumer and Andreas Heider . Some of the remaining open questions: * How are vblank intervals synchronized on retinas to achieve seamless switching? Is the DP mux capable of this? It's not mentioned in the data sheets. Or is it done at the OS level, i.e. do we have to synchronize vblank intervals between DRM drivers? There's a signal coming from the panel connector and going into gmux, could this be the vblank signal as received by the panel to properly time the switch? * On retinas there's an I2C bus between gmux and the connector of the right I/O board, apparently leading to the Parade PS8401A HDMI repeater. What is this for, is it controlled via gmux registers? Data sheet: http://www.paradetech.com/products/jitter-cleaning-repeaters/ps8401/ * On retinas there's an I2C bus between gmux and the LED driver. Pre-retinas connected the LED driver to SMBUS. Are there additional gmux registers on retinas to control it? * The MacPro6,1 2013 also has a gmux, the same Renesas R4F2113 as the retina MacBook Pro. The Mac Pro doesn't have a built-in display, so what is its purpose? Power control of the dual FirePro GPUs? Switching of the external DP/Thunderbolt ports? The iFixit teardown clearly shows one TI HD3SS212 DisplayPort mux on the logic board next to one of the three Thunderbolt controllers. However six muxes would be necessary to switch all six ports between GPUs. The mux is probably necessary for one of the display configurations allowed by Apple, but which one? https://www.ifixit.com/Teardown/Mac+Pro+Late+2013+Teardown/20778 https://d3nevzfk7ii3be.cloudfront.net/igi/fELBTnt31QhnDsqq.huge https://support.apple.com/en-us/HT202801 * Registers we haven't decoded yet: 0x700 32 Bit configmap? 0x708 32 Bit power sequence? 0x712 8 Bit status of clock from panel on retinas? 0x713 8 Bit dito? 0x724 16 Bit backlight, raw value? 0x760 32 Bit backlight 0x764 32 Bit backlight 0x768 8 Bit backlight 0x76a 16 Bit backlight 0x76c 16 Bit backlight 0x76e 16 Bit backlight 0x77f edp/dp/hdmi probe? retina only. * Addition by Bruno Prémont : "Missing is also precise knowledge as to what the gmux depends on. From behavioral reports, it is somehow sensitive to VGA IO/MEM routing (it apparently needs the routing to go to integrated GPU, not discrete GPU). When the routing is inappropriate backlight control IO just reads back as 0xFF (and eventually gmux IO in general does so)." Signed-off-by: Lukas Wunner Acked-by: Darren Hart Link: http://patchwork.freedesktop.org/patch/msgid/da309e436fbeac886477d80376457b7d83ea4b2d.1452431795.git.lukas@wunner.de Signed-off-by: Daniel Vetter

drm/docs: more leftovers from the big vtable documentation pile

2016-01-05T15:21:35Z

Another pile of vfuncs from the old gpu.tmpl xml documentation that I've forgotten to delete. I spotted a few more things to clarify/extend in the new kerneldoc while going through this once more. v2: Spelling fixes (Thierry). v3: More spelling fixes and use Thierry's proposal to clarify why drivers need to validate modes both in ->mode_fixup and ->mode_valid. Cc: Laurent Pinchart Cc: Thierry Reding Acked-by: Thierry Reding Signed-off-by: Daniel Vetter

vga_switcheroo: Prettify documentation

2016-01-04T07:11:49Z

Fix indentation of vga_switcheroo sections in gpu.tmpl. Change section type of API documentation from "chapter" to "sect1" so that the individual functions no longer clutter up the ToC. Group together under a new "API" chapter. Fix wording "heretoforth" -> "henceforth". Signed-off-by: Lukas Wunner Signed-off-by: Daniel Vetter

drm: Move more framebuffer doc from docbook to kerneldoc

2015-12-15T09:22:27Z

I missed a few paragraphs in the docbook that need to be pulled into the fbdev vfunc docs. v2: Spelling fixes from Thierry. Cc: Thierry Reding Link: http://patchwork.freedesktop.org/patch/msgid/1449564561-3896-3-git-send-email-daniel.vetter@ffwll.ch Reviewed-by: Thierry Reding Signed-off-by: Daniel Vetter

drm/doc: Convert to markdown

2015-12-15T09:22:26Z

DRM Docbook is now Markdown ready. This means its doc is able to use markdown text on it. * Documentation/DocBook/drm.tmpl: Contains a table duplicated from drivers/gpu/drm/i915/i915_reg.h. This is not needed anymore * drivers/gpu/drm/drm_modeset_lock.c: had a code example that used to look pretty bad on html. Fixed by using proper code markup. * drivers/gpu/drm/drm_prime.c: Remove spaces between lines to make a proper markup list. * drivers/gpu/drm/i915/i915_reg.h: Altought pandoc supports tables, it doesn't support table cell spanning. But we can use fixed-width for those special cases. * include/drm/drm_vma_manager.h: Another code example that should be proper indented with four spaces. v2 (Daniel): Adjust name to gpu.xml due to rename. v3 (Daniel): Split out the actual enabling in the Makefile - this way we can merge the conversion, while just keeping the enabling in a drm-private tree. Signed-off-by: Danilo Cesar Lemes de Paula (v1) Cc: Randy Dunlap Cc: Daniel Vetter Cc: Laurent Pinchart Cc: Jonathan Corbet Cc: Herbert Xu Cc: Stephan Mueller Cc: Michal Marek Cc: linux-kernel@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: intel-gfx Cc: dri-devel Acked-by: Dave Airlie Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1448471279-19748-2-git-send-email-daniel.vetter@ffwll.ch

drm: Documentation style guide

2015-12-09T16:07:25Z

Every time I type or review docs this seems a bit different. Try to document the common style so we can try to unify at least new docs. v2: Spelling fixes from Pierre, Laurent and Jani. v3: More spelling fixes from Lukas. Cc: Pierre Moreau Cc: Jani Nikula Cc: Laurent Pinchart Cc: Lukas Wunner Acked-by: Laurent Pinchart Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1449564561-3896-1-git-send-email-daniel.vetter@ffwll.ch

drm: Move drm_display_mode an related docs into kerneldoc

2015-12-09T08:29:36Z

This was in the documentation for modeset helper hooks, where it is a bit misplaced. v2: Reindent the drm_mode_status enum, inspired by Ville. v3: Suggestions from Ville and Thierry. v4: Small fixup that 0day spotted. v5: Slight change to avoid accidental headings in kerneldoc output. Cc: ville.syrjala@linux.intel.com Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-27-git-send-email-daniel.vetter@ffwll.ch Reviewed-by: Ville Syrjälä (v3) Reviewed-by: Thierry Reding (v3)

drm: document drm_crtc_funcs

2015-12-08T15:13:52Z

And merge any docbook we have into the kerneldoc comments. Since it's a legacy entry point with only two implementation (one each in atomic and legacy crtc helpers) I've made the documentation for set_config fairly sparse - no one should ever need to look at this again, all the ABI we have is baked into code. For ->page_flip otoh I kept all the extensive docs from the docbook and even extended it where it was lacking: Currently we have a pile of legacy page_flip implemantations, and even for atomic drivers there's not yet a standard implementation in the helpers. Which means every driver needs to implement this itself, and precise specs are really valuable. Otherwise there's just cursor, which really just boils down to "use at least universal planes". And gamma tables (where we have a bit a mess with the fbdev helper gamma hooks). v2: Spelling fixes (Eric). v3: Suggestions from Thierry. Cc: Eric Anholt Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-20-git-send-email-daniel.vetter@ffwll.ch

drm: Document drm_atomic_*_get_property

2015-12-08T15:13:50Z

Yes these are internal functions and not exported and we generally don't document them. But for symmetry with the _set_property functions (which are exported for the atomic helpers) I'd like to document them. Upcoming vtable kerneldoc will reference both the set and get_property functions. v2: Suggestions from Thierry. Signed-off-by: Daniel Vetter Reviewed-by: Thierry Reding Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-17-git-send-email-daniel.vetter@ffwll.ch

drm: Update drm_plane_funcs kerneldoc

2015-12-08T15:07:53Z

- Merge the docbook into the kerneldoc comments. - Spec in detail the precise semantics of the callbacks. - For consistency in wording and easier review roll out kerneldoc also for crtc, encoder and connector for the standard hooks they share with planes. v2: Suggestions from Thierry. Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1449218769-16577-8-git-send-email-daniel.vetter@ffwll.ch Reviewed-by: Thierry Reding