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.

Signed-off-by: Marek Vasut <ma...@denx.de>
Cc: Alexandre Torgue <alexandre.tor...@st.com>
Cc: Andrzej Hajda <a.ha...@samsung.com>
Cc: Antonio Borneo <antonio.bor...@st.com>
Cc: Benjamin Gaignard <benjamin.gaign...@st.com>
Cc: Biju Das <biju.das...@bp.renesas.com>
Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
Cc: Maxime Coquelin <mcoquelin.st...@gmail.com>
Cc: Philippe Cornu <philippe.co...@st.com>
Cc: Sam Ravnborg <s...@ravnborg.org>
Cc: Vincent Abriou <vincent.abr...@st.com>
Cc: Yannick Fertre <yannick.fer...@st.com>
Cc: linux-arm-ker...@lists.infradead.org
Cc: linux-st...@st-md-mailman.stormreply.com
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
      version of this patch must be reworked
---
 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 dcf579a4cf83..8a7cb267ab14 100644
--- a/drivers/gpu/drm/bridge/lvds-codec.c
+++ b/drivers/gpu/drm/bridge/lvds-codec.c
@@ -19,6 +19,7 @@ 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;
@@ -80,6 +81,7 @@ static int lvds_codec_probe(struct platform_device *pdev)
        struct device_node *panel_node;
        struct drm_panel *panel;
        struct lvds_codec *lvds_codec;
+       u32 val;
 
        lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
        if (!lvds_codec)
@@ -119,6 +121,18 @@ static int lvds_codec_probe(struct platform_device *pdev)
        if (IS_ERR(lvds_codec->panel_bridge))
                return PTR_ERR(lvds_codec->panel_bridge);
 
+       /*
+        * 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
@@ -126,6 +140,7 @@ static int lvds_codec_probe(struct platform_device *pdev)
         */
        lvds_codec->bridge.of_node = dev->of_node;
        lvds_codec->bridge.funcs = &funcs;
+       lvds_codec->bridge.timings = &lvds_codec->timings;
        drm_bridge_add(&lvds_codec->bridge);
 
        platform_set_drvdata(pdev, lvds_codec);
-- 
2.30.2

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