[PATCH 2/4 v7] drm/bridge: Provide a way to embed timing info in bridges

[laurent.pinchart@ideasonboard.com (Laurent Pinchart)]

Hi Linus,

Thank you for the patch.

On Friday, 12 January 2018 09:48:52 EET 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@linaro.org>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
> ChangeLog v6->v7:
> - Fix the comment style to use the new inline type of kerneldoc
>   for struct members.
> - Need an explicit ACK/review by someone on this patch to continue
>   with the series...
> 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 | 33 +++++++++++++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
> index 682d01ba920c..d3c2eea0bb63 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 +223,35 @@ struct drm_bridge_funcs {
>  	void (*enable)(struct drm_bridge *bridge);
>  };
> 
> +/**
> + * struct drm_bridge_timings - timing information for the bridge
> + */
> +struct drm_bridge_timings {
> +	/**
> +	 * @sampling_edge:
> +	 *
> +	 * Tells 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).
> +	 */
> +	u32 sampling_edge;
> +	/**
> +	 * @setup_time_ps:
> +	 *
> +	 * Defines the time in picoseconds the input data lines must be
> +	 * stable before the clock edge.
> +	 */
> +	u32 setup_time_ps;
> +	/**
> +	 * @hold_time_ps:
> +	 *
> +	 * Defines the time in picoseconds taken for the bridge to sample the
> +	 * input signal after the clock edge.
> +	 */
> +	u32 hold_time_ps;
> +};
> +
>  /**
>   * struct drm_bridge - central DRM bridge control structure
>   * @dev: DRM device this bridge belongs to
> @@ -229,6 +259,8 @@ 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 +272,7 @@ 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;


-- 
Regards,

Laurent Pinchart