On Wed, Jan 10, 2018 at 03:12:24PM +0100, Linus Walleij wrote:
> After some discussion and failed patch sets trying to convey
> the right timing information between the display engine and
> a bridge using the connector, I try instead to use an optional
> timing information container in the bridge itself, so that
> display engines can retrieve it from any bridge and use it to
> determine how to drive outputs.
>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> ChangeLog v5->v6:
> - Sort forward struct declarations alphabetically
> - Switch to using DRM_BUS_FLAG_PIXDATA_[POS|NEG]EDGE to indicate
> positive or negatice clock samling edge
> ChangeLog ->v5:
> - New patch
> ---
> include/drm/drm_bridge.h | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
> index 682d01ba920c..28c9ac6d9036 100644
> --- a/include/drm/drm_bridge.h
> +++ b/include/drm/drm_bridge.h
> @@ -29,6 +29,7 @@
> #include <drm/drm_modes.h>
>
> struct drm_bridge;
> +struct drm_bridge_timings;
> struct drm_panel;
>
> /**
> @@ -222,6 +223,23 @@ struct drm_bridge_funcs {
> void (*enable)(struct drm_bridge *bridge);
> };
>
> +/**
> + * struct drm_bridge_timings - timing information for the bridge
> + * @sampling_edge: whether the bridge samples the digital input signal from the
> + * display engine on the positive or negative edge of the clock, this should
> + * reuse the DRM_BUS_FLAG_PIXDATA_[POS|NEG]EDGE bitwise flags from the DRM
> + * connector (bit 2 and 3 valid)
> + * @setup_time_ps: the time in picoseconds the input data lines must be stable
> + * before the clock edge
> + * @hold_time_ps: the time in picoseconds taken for the bridge to sample the
> + * input signal after the clock edge
> + */
Just a style nit: for longer kerneldoc comments for struct members the
in-line style, split up for each member, is imo better.
-Daniel
> +struct drm_bridge_timings {
> + u32 sampling_edge;
> + u32 setup_time_ps;
> + u32 hold_time_ps;
> +};
> +
> /**
> * struct drm_bridge - central DRM bridge control structure
> * @dev: DRM device this bridge belongs to
> @@ -229,6 +247,8 @@ struct drm_bridge_funcs {
> * @next: the next bridge in the encoder chain
> * @of_node: device node pointer to the bridge
> * @list: to keep track of all added bridges
> + * @timings: the timing specification for the bridge, if any (may
> + * be NULL)
> * @funcs: control functions
> * @driver_private: pointer to the bridge driver's internal context
> */
> @@ -240,6 +260,7 @@ struct drm_bridge {
> struct device_node *of_node;
> #endif
> struct list_head list;
> + const struct drm_bridge_timings *timings;
>
> const struct drm_bridge_funcs *funcs;
> void *driver_private;
> --
> 2.14.3
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel
