[PATCH v4 00/11] drm: Add Allwinner A10 display engine support
Maxime Ripard
maxime.ripard at free-electrons.com
Wed May 4 11:01:43 PDT 2016
On Mon, Apr 25, 2016 at 03:22:41PM +0200, Maxime Ripard wrote:
> Hi everyone,
>
> The Allwinner SoCs (except for the very latest ones) all share the
> same set of controllers, loosely coupled together to form the display
> pipeline.
>
> Depending on the SoC, the number of instances of the controller will
> change (2 instances of each in the A10, only one in the A13, for
> example), and the output availables will change too (HDMI, composite,
> VGA on the A20, none of them on the A13).
>
> On most featured SoCs, it looks like that:
>
> +--------------------------------------------+
> | RAM |
> +--------------------------------------------+
> | | | |
> v | | v
> +----------------+ | | +----------------+
> | Frontend | | | | Frontend |
> +----------------+ | | +----------------+
> | | | |
> v | | v
> +----------------+ | | +----------------+
> | Backend |<+ +>| Backend |
> +----------------+ +----------------+
> | |
> v v
> +----------------+ +----------------+---> LVDS
> | TCON | | TCON |---> RGB
> +----------------+ +----------------+
> | +---+ +---+ |
> | | | |
> v v v v
> +------------+ +------------+ +------------+---> VGA
> | TV Encoder | | HDMI | | TV Encoder |---> Composite
> +------------+ +------------+ +------------+
>
> The current code only assumes that there is a single instance of all
> the controllers. It also supports only the RGB and Composite
> interfaces.
>
> Let me know what you think,
> Maxime
>
> Changes from v3:
> - Fixed a circular dependency issue found when building as a module
> - Changed a bit the mode_valid checks
> - Fixed an issue with the timings generated by the display engine
>
> - Changed the DT bindings according to Rob feedback (removed the
> allwinner,panel property, documented the endpoints indices, always
> use the frontend as the pipeline entrypoint)
>
> - Changed the display clocks according to Stephen comments (marked
> structures as const, changed a variable name)
>
> Changes from v2:
> - Rebased on top of next-20160318
>
> - Dropped the generic clock regmap conversion and implemented a
> custom clock for our pixel clock, backed by a regmap
> - Added the reset bits for the tcon channel 0 and display clocks
> - Used the new generic gates compatible for the DRAM gates
> - Few clock fixes (missing iounmap, return error checks, etc)
> - Found out that the TCON channel 1 clock was not operating properly
> because of some weird rounding down and up between the various
> generic clocks involved. Rewrote it using custom operations
>
> - Removed some TODO that were still there
> - Converted our panel DT description to the OF graph instead of a
> custom property
> - Tested the driver on a setup where U-Boot was not initialising the
> display, or initialising it on a different output, and fixed a
> number of associated bugs (mostly related to missing
> initialisation bits, missing reset handles, and so on)
> - Fixed the layer code that was assuming that the X and Y
> coordinates were in pixels, leading to a miscalculation of the
> buffer address when those coordinates where set.
> - Added the missing EXPORT_SYMBOL calls
>
> - Fixed our VBLANK interrupt code that was completely broken (and
> not usable, which is why it was unnoticed)
>
> Changes from v1:
> - Rebased on top of 4.4
>
> - Merged the clock drivers for the display and TCON channel 0 clocks
> - Replaced the container_of calls in the display reset clocks to an
> inline function
> - Checked the return code of of_clk_parent_fill in the clocks
> drivers
> - Checked the return code of of_clk_add_provider in the tcon-ch1 and
> PLL3 clocks
> - Added missing clocks headers
> - Created a composite clock unregister function
>
> - Moved the binding documentation to
> Documentation/devicetree/bindings/display
> - Added the clocks binding documentation
> - Added the Olimex vendor to the list of DT vendors
> - Moved to the OF graph representation and the component framework
>
> - Moved the reset cells count check into the reset framework to
> avoid duplicating the code in every xlate implementation.
> - Made the reset_ops const
>
> - Reworked the DRM cmdline mode parsing code to allow named mode
> - Fixed the TV mode lookup when the mode name is not present (for
> example because it was given by the userspace)
>
> - Made the driver outputs optional (to avoid crashing when a board
> doesn't have either a panel or a composite output enabled)
> - Added multiple plane support with transparency
> - Moved the backend registers writes commit in the CRTC atomic_flush
> callback
> - Removed the load / unload functions
> - Removed the enabled booleans in my private structure and removed
> the implicit call to disable_unused_functions in the DRM core to
> push it in the drivers.
> - Fixed a few bitmasks on some bitfields definition
> - Fixed the RGB connector mode validation that was not testing the
> right values
Applied the DT patches.
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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