1 files changed, 46 insertions, 20 deletions

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 735c9081202a..35e884239f60 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -33,6 +33,8 @@
 
 #define MAX_IRQ 4
 
+#define MAX_ENDPOINTS 2
+
 #define HWVER_10200 0x010200
 #define HWVER_10300 0x010300
 #define HWVER_20101 0x020101
@@ -556,7 +558,7 @@ static int ltdc_plane_atomic_check(struct drm_plane *plane,
         src_h = state->src_h >> 16;
 
         /* Reject scaling */
-        if ((src_w != state->crtc_w) || (src_h != state->crtc_h)) {
+        if (src_w != state->crtc_w || src_h != state->crtc_h) {
                 DRM_ERROR("Scaling is not supported");
                 return -EINVAL;
         }
@@ -856,18 +858,33 @@ int ltdc_load(struct drm_device *ddev)
         struct ltdc_device *ldev = ddev->dev_private;
         struct device *dev = ddev->dev;
         struct device_node *np = dev->of_node;
-        struct drm_bridge *bridge;
-        struct drm_panel *panel;
+        struct drm_bridge *bridge[MAX_ENDPOINTS] = {NULL};
+        struct drm_panel *panel[MAX_ENDPOINTS] = {NULL};
         struct drm_crtc *crtc;
         struct reset_control *rstc;
         struct resource *res;
-        int irq, ret, i;
+        int irq, ret, i, endpoint_not_ready = -ENODEV;
 
         DRM_DEBUG_DRIVER("\n");
 
-        ret = drm_of_find_panel_or_bridge(np, 0, 0, &panel, &bridge);
-        if (ret)
-                return ret;
+        /* Get endpoints if any */
+        for (i = 0; i < MAX_ENDPOINTS; i++) {
+                ret = drm_of_find_panel_or_bridge(np, 0, i, &panel[i],
+                                                  &bridge[i]);
+
+                /*
+                 * If at least one endpoint is ready, continue probing,
+                 * else if at least one endpoint is -EPROBE_DEFER and
+                 * there is no previous ready endpoints, defer probing.
+                 */
+                if (!ret)
+                        endpoint_not_ready = 0;
+                else if (ret == -EPROBE_DEFER && endpoint_not_ready)
+                        endpoint_not_ready = -EPROBE_DEFER;
+        }
+
+        if (endpoint_not_ready)
+                return endpoint_not_ready;
 
         rstc = devm_reset_control_get_exclusive(dev, NULL);
 
@@ -928,19 +945,25 @@ int ltdc_load(struct drm_device *ddev)
 
         DRM_INFO("ltdc hw version 0x%08x - ready\n", ldev->caps.hw_version);
 
-        if (panel) {
-                bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DPI);
-                if (IS_ERR(bridge)) {
-                        DRM_ERROR("Failed to create panel-bridge\n");
-                        ret = PTR_ERR(bridge);
-                        goto err;
+        /* Add endpoints panels or bridges if any */
+        for (i = 0; i < MAX_ENDPOINTS; i++) {
+                if (panel[i]) {
+                        bridge[i] = drm_panel_bridge_add(panel[i],
+                                                        DRM_MODE_CONNECTOR_DPI);
+                        if (IS_ERR(bridge[i])) {
+                                DRM_ERROR("panel-bridge endpoint %d\n", i);
+                                ret = PTR_ERR(bridge[i]);
+                                goto err;
+                        }
                 }
-        }
 
-        ret = ltdc_encoder_init(ddev, bridge);
-        if (ret) {
-                DRM_ERROR("Failed to init encoder\n");
-                goto err;
+                if (bridge[i]) {
+                        ret = ltdc_encoder_init(ddev, bridge[i]);
+                        if (ret) {
+                                DRM_ERROR("init encoder endpoint %d\n", i);
+                                goto err;
+                        }
+                }
         }
 
         crtc = devm_kzalloc(dev, sizeof(*crtc), GFP_KERNEL);
@@ -968,7 +991,8 @@ int ltdc_load(struct drm_device *ddev)
         return 0;
 
 err:
-        drm_panel_bridge_remove(bridge);
+        for (i = 0; i < MAX_ENDPOINTS; i++)
+                drm_panel_bridge_remove(bridge[i]);
 
         clk_disable_unprepare(ldev->pixel_clk);
 
@@ -978,10 +1002,12 @@ err:
 void ltdc_unload(struct drm_device *ddev)
 {
         struct ltdc_device *ldev = ddev->dev_private;
+        int i;
 
         DRM_DEBUG_DRIVER("\n");
 
-        drm_of_panel_bridge_remove(ddev->dev->of_node, 0, 0);
+        for (i = 0; i < MAX_ENDPOINTS; i++)
+                drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i);
 
         clk_disable_unprepare(ldev->pixel_clk);
 }