[PATCH] drm/bridge/synopsys: dsi: use mipi_dsi_device to find panel or bridge

[Heiko Stuebner]

From: Heiko Stuebner <heiko.stuebner at theobroma-systems.com>

Right now the dsi driver uses drm_of_find_panel_or_bridge() to find a
connected panel or bridge. But this requires an of-graph connection
between the dsi-host and dsi-device, where normal bindings for regular
panels just expect the dsi device to be a subnode of the actual dsi host
not requiring ports.

drm_of_find_panel_or_bridge is used to find panel/bridge under the actual
device-node of the dsi device, but as this happens in the dsi_host_attach
callback we already have the dsi-device and its device-node available and
therefore can just call the relevant panel+bridge functions ourself,
making it work as well in setups without port-connections.

Tested on a Rockchip px30 single-dsi with panels form Leadtek and Xinpeng
as well on Gru-Scarlet (rk3399) with dual-dsi (and thus port-connections
to both dsi controllers) connected to the Innotek display variant.

changes in v2:
- rework commit message, rereading what I had written was just too
  cringe-worthy ;-)

Signed-off-by: Heiko Stuebner <heiko.stuebner at theobroma-systems.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index 981d532cdd59..4b4961e7c680 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -26,6 +26,7 @@
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_modes.h>
 #include <drm/drm_of.h>
+#include <drm/drm_panel.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
 
@@ -310,16 +311,16 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
 	dsi->format = device->format;
 	dsi->mode_flags = device->mode_flags;
 
-	ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0,
-					  &panel, &bridge);
-	if (ret)
-		return ret;
-
-	if (panel) {
+	panel = of_drm_find_panel(device->dev.of_node);
+	if (!IS_ERR(panel)) {
 		bridge = drm_panel_bridge_add_typed(panel,
 						    DRM_MODE_CONNECTOR_DSI);
 		if (IS_ERR(bridge))
 			return PTR_ERR(bridge);
+	} else {
+		bridge = of_drm_find_bridge(device->dev.of_node);
+		if (!bridge)
+			return -EPROBE_DEFER;
 	}
 
 	dsi->panel_bridge = bridge;
@@ -340,6 +341,7 @@ static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host,
 {
 	struct dw_mipi_dsi *dsi = host_to_dsi(host);
 	const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
+	struct drm_bridge *bridge;
 	int ret;
 
 	if (pdata->host_ops && pdata->host_ops->detach) {
@@ -348,7 +350,8 @@ static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host,
 			return ret;
 	}
 
-	drm_of_panel_bridge_remove(host->dev->of_node, 1, 0);
+	bridge = of_drm_find_bridge(device->dev.of_node);
+	drm_panel_bridge_remove(bridge);
 
 	drm_bridge_remove(&dsi->bridge);
 
-- 
2.24.0