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From:   Rob Clark <robdclark@gmail.com>
To:     dri-devel@lists.freedesktop.org
Cc:     linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Stephen Boyd <swboyd@chromium.org>,
        Douglas Anderson <dianders@chromium.org>,
        Rob Clark <robdclark@chromium.org>,
        Rob Clark <robdclark@gmail.com>, Sean Paul <sean@poorly.run>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Abhinav Kumar <abhinavk@codeaurora.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH 2/4] drm/msm/dsi: Support NO_CONNECTOR bridges
Date:   Wed, 11 Aug 2021 16:52:48 -0700
Message-Id: <20210811235253.924867-3-robdclark@gmail.com>
In-Reply-To: <20210811235253.924867-1-robdclark@gmail.com>
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From: Rob Clark <robdclark@chromium.org>

For now, since we have a mix of bridges which support this flag, which
which do *not* support this flag, or work both ways, try it once with
NO_CONNECTOR and then fall back to the old way if that doesn't work.
Eventually we can drop the fallback path.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
 drivers/gpu/drm/msm/Kconfig           |  2 ++
 drivers/gpu/drm/msm/dsi/dsi_manager.c | 41 ++++++++++++++++++---------
 2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
index e9c6af78b1d7..36e5ba3ccc28 100644
--- a/drivers/gpu/drm/msm/Kconfig
+++ b/drivers/gpu/drm/msm/Kconfig
@@ -14,6 +14,8 @@ config DRM_MSM
 	select REGULATOR
 	select DRM_KMS_HELPER
 	select DRM_PANEL
+	select DRM_BRIDGE
+	select DRM_PANEL_BRIDGE
 	select DRM_SCHED
 	select SHMEM
 	select TMPFS
diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
index c41d39f5b7cf..1fd1cf93abbf 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
@@ -3,6 +3,8 @@
  * Copyright (c) 2015, The Linux Foundation. All rights reserved.
  */
 
+#include "drm/drm_bridge_connector.h"
+
 #include "msm_kms.h"
 #include "dsi.h"
 
@@ -690,8 +692,7 @@ struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id)
 	struct drm_device *dev = msm_dsi->dev;
 	struct drm_encoder *encoder;
 	struct drm_bridge *int_bridge, *ext_bridge;
-	struct drm_connector *connector;
-	struct list_head *connector_list;
+	int ret;
 
 	int_bridge = msm_dsi->bridge;
 	ext_bridge = msm_dsi->external_bridge =
@@ -699,22 +700,36 @@ struct drm_connector *msm_dsi_manager_ext_bridge_init(u8 id)
 
 	encoder = msm_dsi->encoder;
 
-	/* link the internal dsi bridge to the external bridge */
-	drm_bridge_attach(encoder, ext_bridge, int_bridge, 0);
-
 	/*
-	 * we need the drm_connector created by the external bridge
-	 * driver (or someone else) to feed it to our driver's
-	 * priv->connector[] list, mainly for msm_fbdev_init()
+	 * Try first to create the bridge without it creating it's own
+	 * connector.. currently some bridges support this, and others
+	 * do not (and some support both modes)
 	 */
-	connector_list = &dev->mode_config.connector_list;
+	ret = drm_bridge_attach(encoder, ext_bridge, int_bridge,
+			DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+	if (ret == -EINVAL) {
+		struct drm_connector *connector;
+		struct list_head *connector_list;
+
+		/* link the internal dsi bridge to the external bridge */
+		drm_bridge_attach(encoder, ext_bridge, int_bridge, 0);
+
+		/*
+		 * we need the drm_connector created by the external bridge
+		 * driver (or someone else) to feed it to our driver's
+		 * priv->connector[] list, mainly for msm_fbdev_init()
+		 */
+		connector_list = &dev->mode_config.connector_list;
+
+		list_for_each_entry(connector, connector_list, head) {
+			if (drm_connector_has_possible_encoder(connector, encoder))
+				return connector;
+		}
 
-	list_for_each_entry(connector, connector_list, head) {
-		if (drm_connector_has_possible_encoder(connector, encoder))
-			return connector;
+		return ERR_PTR(-ENODEV);
 	}
 
-	return ERR_PTR(-ENODEV);
+	return drm_bridge_connector_init(dev, encoder);
 }
 
 void msm_dsi_manager_bridge_destroy(struct drm_bridge *bridge)
-- 
2.31.1