diff mbox series

[08/36] drm: xlnx: zynqmp_dpsub: Attach to the next bridge

Message ID 20210809013457.11266-9-laurent.pinchart@ideasonboard.com (mailing list archive)
State New, archived
Headers show
Series drm: xlnx: zynqmp_dpsub: Initial live video input support | expand

Commit Message

Laurent Pinchart Aug. 9, 2021, 1:34 a.m. UTC 
The next component in the display chain, after the DP encoder, is most
likely a DP connector. The display connector driver registers a bridge
for it. That bridge doesn't need to be controlled, but is needed in
order to use the DRM connector bridge helper. Retrieve it at init time,
and attach to it in the DP bridge attach handler.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/gpu/drm/xlnx/zynqmp_dp.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
index 27b5277f8f64..244628497e98 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
@@ -282,6 +282,7 @@  struct zynqmp_dp_config {
  * @reset: reset controller
  * @irq: irq
  * @bridge: DRM bridge for the DP encoder
+ * @next_bridge: The downstream bridge
  * @config: IP core configuration from DTS
  * @aux: aux channel
  * @phy: PHY handles for DP lanes
@@ -304,6 +305,7 @@  struct zynqmp_dp {
 	int irq;
 
 	struct drm_bridge bridge;
+	struct drm_bridge *next_bridge;
 
 	struct zynqmp_dp_config config;
 	struct drm_dp_aux aux;
@@ -1306,6 +1308,13 @@  static int zynqmp_dp_bridge_attach(struct drm_bridge *bridge,
 	drm_connector_register(connector);
 	drm_connector_attach_encoder(connector, bridge->encoder);
 
+	if (dp->next_bridge) {
+		ret = drm_bridge_attach(bridge->encoder, dp->next_bridge,
+					bridge, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+		if (ret < 0)
+			return ret;
+	}
+
 	return 0;
 }
 
@@ -1743,6 +1752,15 @@  int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub, struct drm_device *drm)
 	if (ret)
 		goto err_reset;
 
+	/*
+	 * Acquire the next bridge in the chain. Ignore errors caused by port@5
+	 * not being connected for backward-compatibility with older DTs.
+	 */
+	ret = drm_of_find_panel_or_bridge(dp->dev->of_node, 5, 0, NULL,
+					  &dp->next_bridge);
+	if (ret < 0 && ret != -ENODEV)
+		goto err_reset;
+
 	/* Initialize the hardware. */
 	zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN,
 			ZYNQMP_DP_TX_PHY_POWER_DOWN_ALL);