Revert "drm: bridge: mcde_dsi: Switch to devm_drm_of_get_bridge"

commit <3d7039e1e649> ("drm: bridge: mcde_dsi: Switch to devm_drm_of_get_bridge")
switched to devm_drm_of_get_bridge for looking up if child node has panel
or bridge.

However commit <b089c0a9b14c> ("Revert "drm: of: Lookup if child node
has panel or bridge") has reverted panel or bridge child node lookup
from devm_drm_of_get_bridge as it breaks the non-trivial cases the
first child node might not be a panel or bridge.

So, revert this commit to switch the previous behavior of looking up
child panel or bridge.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220429085947.1699963-2-jagan@amarulasolutions.com

diff --git a/drivers/gpu/drm/mcde/mcde_dsi.c b/drivers/gpu/drm/mcde/mcde_dsi.c
index 083a472..5651734 100644 (file)
--- a/drivers/gpu/drm/mcde/mcde_dsi.c
+++ b/drivers/gpu/drm/mcde/mcde_dsi.c
@@ -19,6 +19,7 @@
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_modeset_helper_vtables.h>
 #include <drm/drm_of.h>
+#include <drm/drm_panel.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
 
@@ -38,6 +39,7 @@ struct mcde_dsi {
        struct device *dev;
        struct mcde *mcde;
        struct drm_bridge bridge;
+       struct drm_panel *panel;
        struct drm_bridge *bridge_out;
        struct mipi_dsi_host dsi_host;
        struct mipi_dsi_device *mdsi;
@@ -1071,7 +1073,9 @@ static int mcde_dsi_bind(struct device *dev, struct device *master,
        struct drm_device *drm = data;
        struct mcde *mcde = to_mcde(drm);
        struct mcde_dsi *d = dev_get_drvdata(dev);
-       struct drm_bridge *bridge;
+       struct device_node *child;
+       struct drm_panel *panel = NULL;
+       struct drm_bridge *bridge = NULL;
 
        if (!of_get_available_child_count(dev->of_node)) {
                dev_info(dev, "unused DSI interface\n");
@@ -1096,10 +1100,37 @@ static int mcde_dsi_bind(struct device *dev, struct device *master,
                return PTR_ERR(d->lp_clk);
        }
 
-       bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);
-       if (IS_ERR(bridge)) {
-               dev_err(dev, "error to get bridge\n");
-               return PTR_ERR(bridge);
+       /* Look for a panel as a child to this node */
+       for_each_available_child_of_node(dev->of_node, child) {
+               panel = of_drm_find_panel(child);
+               if (IS_ERR(panel)) {
+                       dev_err(dev, "failed to find panel try bridge (%ld)\n",
+                               PTR_ERR(panel));
+                       panel = NULL;
+
+                       bridge = of_drm_find_bridge(child);
+                       if (!bridge) {
+                               dev_err(dev, "failed to find bridge\n");
+                               return -EINVAL;
+                       }
+               }
+       }
+       if (panel) {
+               bridge = drm_panel_bridge_add_typed(panel,
+                                                   DRM_MODE_CONNECTOR_DSI);
+               if (IS_ERR(bridge)) {
+                       dev_err(dev, "error adding panel bridge\n");
+                       return PTR_ERR(bridge);
+               }
+               dev_info(dev, "connected to panel\n");
+               d->panel = panel;
+       } else if (bridge) {
+               /* TODO: AV8100 HDMI encoder goes here for example */
+               dev_info(dev, "connected to non-panel bridge (unsupported)\n");
+               return -ENODEV;
+       } else {
+               dev_err(dev, "no panel or bridge\n");
+               return -ENODEV;
        }
 
        d->bridge_out = bridge;
@@ -1122,7 +1153,8 @@ static void mcde_dsi_unbind(struct device *dev, struct device *master,
 {
        struct mcde_dsi *d = dev_get_drvdata(dev);
 
-       drm_bridge_remove(d->bridge_out);
+       if (d->panel)
+               drm_panel_bridge_remove(d->bridge_out);
        regmap_update_bits(d->prcmu, PRCM_DSI_SW_RESET,
                           PRCM_DSI_SW_RESET_DSI0_SW_RESETN, 0);
 }