Hi Marek,
On Sun, Oct 17, 2021 at 02:12:04AM +0200, Marek Vasut wrote:
> The OnSemi FIN3385 Parallel-to-LVDS encoder has a dedicated input line to
> select input pixel data sampling edge. Add DT property "pclk-sample", not
> the same as the one used by display timings but rather the same as used by
> media, and configure bus flags based on this DT property.
Late to the party here - sorry.
>
> Signed-off-by: Marek Vasut <ma...@denx.de>
> Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
> Cc: Rob Herring <robh...@kernel.org>
> Cc: Sam Ravnborg <s...@ravnborg.org>
> Cc: devicet...@vger.kernel.org
> To: dri-devel@lists.freedesktop.org
> ---
> V2: - Limit the pixelclk-active to encoders only
> - Update DT binding document
> V3: - Determine whether this is encoder from connector, i.e.
> lvds_codec->connector_type == DRM_MODE_CONNECTOR_LVDS
> V4: - Switch to pclk-sample. Note that the value of this is inverted,
> so all the existing users of pixelclk-active using previous
> previous version of this patch must be reworked
> V5: Rebase on recent linux-next
> ---
> drivers/gpu/drm/bridge/lvds-codec.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/lvds-codec.c
> b/drivers/gpu/drm/bridge/lvds-codec.c
> index f991842a161f..702ea803a743 100644
> --- a/drivers/gpu/drm/bridge/lvds-codec.c
> +++ b/drivers/gpu/drm/bridge/lvds-codec.c
> @@ -21,6 +21,7 @@ struct lvds_codec {
> struct device *dev;
> struct drm_bridge bridge;
> struct drm_bridge *panel_bridge;
> + struct drm_bridge_timings timings;
> struct regulator *vcc;
> struct gpio_desc *powerdown_gpio;
> u32 connector_type;
> @@ -119,6 +120,7 @@ static int lvds_codec_probe(struct platform_device *pdev)
> struct device_node *bus_node;
> struct drm_panel *panel;
> struct lvds_codec *lvds_codec;
> + u32 val;
> int ret;
>
> lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
> @@ -187,12 +189,25 @@ static int lvds_codec_probe(struct platform_device
> *pdev)
> }
> }
>
> + /*
> + * Encoder might sample data on different clock edge than the display,
> + * for example OnSemi FIN3385 has a dedicated strapping pin to select
> + * the sampling edge.
> + */
> + if (lvds_codec->connector_type == DRM_MODE_CONNECTOR_LVDS &&
> + !of_property_read_u32(dev->of_node, "pclk-sample", &val)) {
> + lvds_codec->timings.input_bus_flags = val ?
> + DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE :
> + DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
> + }
> +
> /*
> * The panel_bridge bridge is attached to the panel's of_node,
> * but we need a bridge attached to our of_node for our user
> * to look up.
> */
> lvds_codec->bridge.of_node = dev->of_node;
> + lvds_codec->bridge.timings = &lvds_codec->timings;
I do not understand how this will work. The only field that is set is
timings.input_bus_flags
but any user will see bridge.timings is set and will think this is all
timing info.
Maybe I just misses something obvious?
Sam
> drm_bridge_add(&lvds_codec->bridge);
>
> platform_set_drvdata(pdev, lvds_codec);
> --
> 2.33.0
