1 files changed, 88 insertions, 50 deletions

diff --git a/drivers/gpu/drm/pl111/pl111_drv.c b/drivers/gpu/drm/pl111/pl111_drv.c
index acb738c69873..1231905150d0 100644
--- a/drivers/gpu/drm/pl111/pl111_drv.c
+++ b/drivers/gpu/drm/pl111/pl111_drv.c
@@ -58,6 +58,8 @@
 #include <linux/dma-buf.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
 
 #include <drm/drmP.h>
 #include <drm/drm_atomic_helper.h>
@@ -85,9 +87,13 @@ static int pl111_modeset_init(struct drm_device *dev)
 {
         struct drm_mode_config *mode_config;
         struct pl111_drm_dev_private *priv = dev->dev_private;
-        struct drm_panel *panel;
-        struct drm_bridge *bridge;
+        struct device_node *np = dev->dev->of_node;
+        struct device_node *remote;
+        struct drm_panel *panel = NULL;
+        struct drm_bridge *bridge = NULL;
+        bool defer = false;
         int ret = 0;
+        int i;
 
         drm_mode_config_init(dev);
         mode_config = &dev->mode_config;
@@ -97,10 +103,54 @@ static int pl111_modeset_init(struct drm_device *dev)
         mode_config->min_height = 1;
         mode_config->max_height = 768;
 
-        ret = drm_of_find_panel_or_bridge(dev->dev->of_node,
-                                          0, 0, &panel, &bridge);
-        if (ret && ret != -ENODEV)
-                return ret;
+        i = 0;
+        for_each_endpoint_of_node(np, remote) {
+                struct drm_panel *tmp_panel;
+                struct drm_bridge *tmp_bridge;
+
+                dev_dbg(dev->dev, "checking endpoint %d\n", i);
+
+                ret = drm_of_find_panel_or_bridge(dev->dev->of_node,
+                                                  0, i,
+                                                  &tmp_panel,
+                                                  &tmp_bridge);
+                if (ret) {
+                        if (ret == -EPROBE_DEFER) {
+                                /*
+                                 * Something deferred, but that is often just
+                                 * another way of saying -ENODEV, but let's
+                                 * cast a vote for later deferral.
+                                 */
+                                defer = true;
+                        } else if (ret != -ENODEV) {
+                                /* Continue, maybe something else is working */
+                                dev_err(dev->dev,
+                                        "endpoint %d returns %d\n", i, ret);
+                        }
+                }
+
+                if (tmp_panel) {
+                        dev_info(dev->dev,
+                                 "found panel on endpoint %d\n", i);
+                        panel = tmp_panel;
+                }
+                if (tmp_bridge) {
+                        dev_info(dev->dev,
+                                 "found bridge on endpoint %d\n", i);
+                        bridge = tmp_bridge;
+                }
+
+                i++;
+        }
+
+        /*
+         * If we can't find neither panel nor bridge on any of the
+         * endpoints, and any of them retured -EPROBE_DEFER, then
+         * let's defer this driver too.
+         */
+        if ((!panel && !bridge) && defer)
+                return -EPROBE_DEFER;
+
         if (panel) {
                 bridge = drm_panel_bridge_add(panel,
                                               DRM_MODE_CONNECTOR_Unknown);
@@ -108,11 +158,17 @@ static int pl111_modeset_init(struct drm_device *dev)
                         ret = PTR_ERR(bridge);
                         goto out_config;
                 }
-                /*
-                 * TODO: when we are using a different bridge than a panel
-                 * (such as a dumb VGA connector) we need to devise a different
-                 * method to get the connector out of the bridge.
-                 */
+        } else if (bridge) {
+                dev_info(dev->dev, "Using non-panel bridge\n");
+        } else {
+                dev_err(dev->dev, "No bridge, exiting\n");
+                return -ENODEV;
+        }
+
+        priv->bridge = bridge;
+        if (panel) {
+                priv->panel = panel;
+                priv->connector = panel->connector;
         }
 
         ret = pl111_display_init(dev);
@@ -126,14 +182,12 @@ static int pl111_modeset_init(struct drm_device *dev)
         if (ret)
                 return ret;
 
-        priv->bridge = bridge;
-        priv->panel = panel;
-        priv->connector = panel->connector;
-
-        ret = drm_vblank_init(dev, 1);
-        if (ret != 0) {
-                dev_err(dev->dev, "Failed to init vblank\n");
-                goto out_bridge;
+        if (!priv->variant->broken_vblank) {
+                ret = drm_vblank_init(dev, 1);
+                if (ret != 0) {
+                        dev_err(dev->dev, "Failed to init vblank\n");
+                        goto out_bridge;
+                }
         }
 
         drm_mode_config_reset(dev);
@@ -170,10 +224,6 @@ static struct drm_driver pl111_drm_driver = {
         .dumb_create = drm_gem_cma_dumb_create,
         .gem_free_object_unlocked = drm_gem_cma_free_object,
         .gem_vm_ops = &drm_gem_cma_vm_ops,
-
-        .enable_vblank = pl111_enable_vblank,
-        .disable_vblank = pl111_disable_vblank,
-
         .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
         .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
         .gem_prime_import = drm_gem_prime_import,
@@ -191,7 +241,7 @@ static int pl111_amba_probe(struct amba_device *amba_dev,
 {
         struct device *dev = &amba_dev->dev;
         struct pl111_drm_dev_private *priv;
-        struct pl111_variant_data *variant = id->data;
+        const struct pl111_variant_data *variant = id->data;
         struct drm_device *drm;
         int ret;
 
@@ -199,6 +249,11 @@ static int pl111_amba_probe(struct amba_device *amba_dev,
         if (!priv)
                 return -ENOMEM;
 
+        if (!variant->broken_vblank) {
+                pl111_drm_driver.enable_vblank = pl111_enable_vblank;
+                pl111_drm_driver.disable_vblank = pl111_disable_vblank;
+        }
+
         drm = drm_dev_alloc(&pl111_drm_driver, dev);
         if (IS_ERR(drm))
                 return PTR_ERR(drm);
@@ -207,27 +262,10 @@ static int pl111_amba_probe(struct amba_device *amba_dev,
         drm->dev_private = priv;
         priv->variant = variant;
 
-        /*
-         * The PL110 and PL111 variants have two registers
-         * swapped: interrupt enable and control. For this reason
-         * we use offsets that we can change per variant.
-         */
+        /* The two variants swap this register */
         if (variant->is_pl110) {
-                /*
-                 * The ARM Versatile boards are even more special:
-                 * their PrimeCell ID say they are PL110 but the
-                 * control and interrupt enable registers are anyway
-                 * swapped to the PL111 order so they are not following
-                 * the PL110 datasheet.
-                 */
-                if (of_machine_is_compatible("arm,versatile-ab") ||
-                    of_machine_is_compatible("arm,versatile-pb")) {
-                        priv->ienb = CLCD_PL111_IENB;
-                        priv->ctrl = CLCD_PL111_CNTL;
-                } else {
-                        priv->ienb = CLCD_PL110_IENB;
-                        priv->ctrl = CLCD_PL110_CNTL;
-                }
+                priv->ienb = CLCD_PL110_IENB;
+                priv->ctrl = CLCD_PL110_CNTL;
         } else {
                 priv->ienb = CLCD_PL111_IENB;
                 priv->ctrl = CLCD_PL111_CNTL;
@@ -239,6 +277,11 @@ static int pl111_amba_probe(struct amba_device *amba_dev,
                 return PTR_ERR(priv->regs);
         }
 
+        /* This may override some variant settings */
+        ret = pl111_versatile_init(dev, priv);
+        if (ret)
+                goto dev_unref;
+
         /* turn off interrupts before requesting the irq */
         writel(0, priv->regs + priv->ienb);
 
@@ -249,10 +292,6 @@ static int pl111_amba_probe(struct amba_device *amba_dev,
                 return ret;
         }
 
-        ret = pl111_versatile_init(dev, priv);
-        if (ret)
-                goto dev_unref;
-
         ret = pl111_modeset_init(drm);
         if (ret != 0)
                 goto dev_unref;
@@ -284,8 +323,7 @@ static int pl111_amba_remove(struct amba_device *amba_dev)
 }
 
 /*
- * This variant exist in early versions like the ARM Integrator
- * and this version lacks the 565 and 444 pixel formats.
+ * This early variant lacks the 565 and 444 pixel formats.
  */
 static const u32 pl110_pixel_formats[] = {
         DRM_FORMAT_ABGR8888,