@@ -1470,18 +1470,52 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
struct device *dev = dsi->dev;
struct drm_encoder *encoder = &dsi->encoder;
struct drm_device *drm = encoder->dev;
+ struct device_node *np = dev->of_node;
+ struct device_node *remote;
struct drm_panel *panel;
int ret;
- panel = of_drm_find_panel(device->dev.of_node);
+ /*
+ * Devices can also be child nodes when we also control that device
+ * through the upstream device (ie, MIPI-DCS for a MIPI-DSI device).
+ *
+ * Lookup for a child node of the given parent that isn't either port
+ * or ports.
+ */
+ for_each_available_child_of_node(np, remote) {
+ if (of_node_name_eq(remote, "port") ||
+ of_node_name_eq(remote, "ports"))
+ continue;
+
+ goto of_find_panel_or_bridge;
+ }
+
+ /*
+ * of_graph_get_remote_node() produces a noisy error message if port
+ * node isn't found and the absence of the port is a legit case here,
+ * so at first we silently check whether graph presents in the
+ * device-tree node.
+ */
+ if (!of_graph_is_present(np))
+ return -ENODEV;
+
+ remote = of_graph_get_remote_node(np, 1, 0);
+
+of_find_panel_or_bridge:
+ if (!remote)
+ return -ENODEV;
+
+ panel = of_drm_find_panel(remote);
if (!IS_ERR(panel)) {
dsi->out_bridge = devm_drm_panel_bridge_add(dev, panel);
} else {
- dsi->out_bridge = of_drm_find_bridge(device->dev.of_node);
+ dsi->out_bridge = of_drm_find_bridge(remote);
if (!dsi->out_bridge)
dsi->out_bridge = ERR_PTR(-EINVAL);
}
+ of_node_put(remote);
+
if (IS_ERR(dsi->out_bridge)) {
ret = PTR_ERR(dsi->out_bridge);
DRM_DEV_ERROR(dev, "failed to find the bridge: %d\n", ret);
In general, for MIPI DSI there are three ways to represent the pipeline for an upstream bridge to find the connected downstream panel or bridge. 1. Child panel or bridge as a conventional device tree child node. 2. Child panel or bridge as an OF-graph port node. 3. Child panel or bridge as an OF-graph ports node. There are three different downstream panels or bridges that are possible to connect an upstream DSI host bridge - DSI Panel, DSI Bridge, and I2C-Configured DSI bridge. An example of the downstream panel represented as a child node, &dsi { compatible = "samsung,exynos5433-mipi-dsi"; ports { port@0 { reg = <0>; dsi_to_mic: endpoint { remote-endpoint = <&mic_to_dsi>; }; }; }; panel@0 { reg = <0>; }; }; An example of the downstream bridge represented as a port node, &i2c4 { bridge@2c { compatible = "ti,sn65dsi84"; ports { port@0 { reg = <0>; bridge_in_dsi: endpoint { remote-endpoint = <&dsi_out_bridge>; data-lanes = <1 2>; }; }; port@2 { reg = <2>; bridge_out_panel: endpoint { remote-endpoint = <&panel_out_bridge>; }; }; }; }; }; &dsi { compatible = "fsl,imx8mm-mipi-dsim"; port { dsi_in_lcdif: endpoint@0 { reg = <0>; remote-endpoint = <&lcdif_out_dsi>; }; dsi_out_bridge: endpoint@1 { reg = <1>; remote-endpoint = <&bridge_in_dsi>; }; }; }; An example of the downstream bridge represented as a ports node, &dsi { compatible = "fsl,imx8mm-mipi-dsim"; ports { port@0 { reg = <0>; dsi_in_lcdif: endpoint@0 { reg = <0>; remote-endpoint = <&lcdif_out_dsi>; }; }; port@1 { reg = <1>; dsi_out_bridge: endpoint { remote-endpoint = <&bridge_in_dsi>; }; }; }; In, summary it is possible to represent all three downstream slaves devices using OF-graph port or ports node however only DSI Panel and DSI Bridge are possible but not possible to represent I2C-Configured DSI bridge child nodes since I2C-Configure bridges are child of I2C node, not upstream DSI host bridge and it is must represent them endpoint port linking. This indeed means, the OF-graph port or ports representation is mandatory for I2C-Configured DSI bridges. This patch tries to add an OF-graph port or ports representation detection code on top of existing child node detection. It is possible to replace the entire detection code using existing drm_of helper drm_of_find_panel_or_bridge but it will break the Exynos DSI since the pipeline doesn't support OF-graph port or ports node. Overall, this patch has a combination of child and OF-graph pipeline detections in order to support the backward compatibility of Exynos DSI child node and i.MX8M Mini/Nano/Plus OF-graph port or ports node pipelines. This is the first common DSI host bridge driver that needs to support all possible downstream connection pipeline combinations. Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Marek Vasut <marex@denx.de> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com> --- Changes for v16: - collect TB from Marek S - collect RB from Marek V - fix multiline comment Changes for v15: - droped from drm_of - added in exynos dsi - updated commit messages Changes for v13, v12: - none Changes for v11: - drop extra line Changes for v10: - new patch drivers/gpu/drm/exynos/exynos_drm_dsi.c | 38 +++++++++++++++++++++++-- 1 file changed, 36 insertions(+), 2 deletions(-)