drm/pl111: Replace custom connector with panel bridge

This replaces the custom connector in the PL111 with the
panel bridge helper.

This works nicely for all standard panels, but since there
are several PL11x-based systems that will need to use the dumb
VGA connector bridge we use drm_of_find_panel_or_bridge()
and make some headroom for dealing with bridges that are
not panels as well, and drop a TODO in the code.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908124709.4758-3-linus.walleij@linaro.org

1 files changed, 37 insertions, 18 deletions

diff --git a/drivers/gpu/drm/pl111/pl111_drv.c b/drivers/gpu/drm/pl111/pl111_drv.c
index 581c452cede1..7dae687a8df4 100644
--- a/drivers/gpu/drm/pl111/pl111_drv.c
+++ b/drivers/gpu/drm/pl111/pl111_drv.c
@@ -68,6 +68,9 @@
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_of.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_panel.h>
 
 #include "pl111_drm.h"
 
@@ -83,6 +86,8 @@ 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;
 	int ret = 0;
 
 	drm_mode_config_init(dev);
@@ -93,34 +98,43 @@ static int pl111_modeset_init(struct drm_device *dev)
 	mode_config->min_height = 1;
 	mode_config->max_height = 768;
 
-	ret = pl111_connector_init(dev);
-	if (ret) {
-		dev_err(dev->dev, "Failed to create pl111_drm_connector\n");
-		goto out_config;
-	}
-
-	/* Don't actually attach if we didn't find a drm_panel
-	 * attached to us.  This will allow a kernel to include both
-	 * the fbdev pl111 driver and this one, and choose between
-	 * them based on which subsystem has support for the panel.
-	 */
-	if (!priv->connector.panel) {
-		dev_info(dev->dev,
-			 "Disabling due to lack of DRM panel device.\n");
-		ret = -ENODEV;
-		goto out_config;
+	ret = drm_of_find_panel_or_bridge(dev->dev->of_node,
+					  0, 0, &panel, &bridge);
+	if (ret && ret != -ENODEV)
+		return ret;
+	if (panel) {
+		bridge = drm_panel_bridge_add(panel,
+					      DRM_MODE_CONNECTOR_Unknown);
+		if (IS_ERR(bridge)) {
+			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.
+		 */
 	}
 
 	ret = pl111_display_init(dev);
 	if (ret != 0) {
 		dev_err(dev->dev, "Failed to init display\n");
-		goto out_config;
+		goto out_bridge;
 	}
 
+	ret = drm_simple_display_pipe_attach_bridge(&priv->pipe,
+						    bridge);
+	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_config;
+		goto out_bridge;
 	}
 
 	drm_mode_config_reset(dev);
@@ -132,6 +146,9 @@ static int pl111_modeset_init(struct drm_device *dev)
 
 	goto finish;
 
+out_bridge:
+	if (panel)
+		drm_panel_bridge_remove(bridge);
 out_config:
 	drm_mode_config_cleanup(dev);
 finish:
@@ -236,6 +253,8 @@ static int pl111_amba_remove(struct amba_device *amba_dev)
 	drm_dev_unregister(drm);
 	if (priv->fbdev)
 		drm_fbdev_cma_fini(priv->fbdev);
+	if (priv->panel)
+		drm_panel_bridge_remove(priv->bridge);
 	drm_mode_config_cleanup(drm);
 	drm_dev_unref(drm);