[PATCH v4 4/4] drm/lcdif: add DRM_BRIDGE_ATTACH_NO_CONNECTOR flag to drm_bridge_attach

[Marek Vasut <marex@denx.de>]

Commit a25b988ff83f ("drm/bridge: Extend bridge API to disable connector creation")
added DRM_BRIDGE_ATTACH_NO_CONNECTOR bridge flag and all bridges handle
this flag in some way since then.
Newly added bridge drivers must no longer contain the connector creation and
will fail probing if this flag isn't set.

In order to be able to connect to those newly added bridges as well,
make use of drm_bridge_connector API and have the connector initialized
by the display controller.

Based on 2e87bf389e13 ("drm/rockchip: add DRM_BRIDGE_ATTACH_NO_CONNECTOR flag to drm_bridge_attach")

This makes LT9611 work with i.MX8M Plus.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Liu Ying <victor.liu@nxp.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Robert Foss <rfoss@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Simona Vetter <simona@ffwll.ch>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: dri-devel@lists.freedesktop.org
Cc: imx@lists.linux.dev
Cc: linux-arm-kernel@lists.infradead.org
---
V2: Add RB from Dmitry
V3: - Select DRM_DISPLAY_HELPER
    - Use return dev_err_probe() directly
    - Add missing of_node_put(ep)
    - Add test using drm_bridge_get_next_bridge() to try and determine
      if the HDMI connector was missing in DT or not, and if it was
      missing, if it was created by the HDMI bridge driver.
V4: - Swap the DRM_BRIDGE_CONNECTOR and DRM_DISPLAY_HELPER in the right symbols
    - Reorder the patches, swap 3/4 and 4/4 in the series
    - Drop the HDMI bridge test, create connector here
---
 drivers/gpu/drm/mxsfb/Kconfig     |  2 ++
 drivers/gpu/drm/mxsfb/lcdif_drv.c | 24 ++++++++++++++++++++++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mxsfb/Kconfig b/drivers/gpu/drm/mxsfb/Kconfig
index 26bb2dbba49e3..eb51d38455a6c 100644
--- a/drivers/gpu/drm/mxsfb/Kconfig
+++ b/drivers/gpu/drm/mxsfb/Kconfig
@@ -30,8 +30,10 @@ config DRM_IMX_LCDIF
 	depends on COMMON_CLK
 	depends on ARCH_MXC || COMPILE_TEST
 	select DRM_CLIENT_SELECTION
+	select DRM_DISPLAY_HELPER
 	select DRM_MXS
 	select DRM_KMS_HELPER
+	select DRM_BRIDGE_CONNECTOR
 	select DRM_GEM_DMA_HELPER
 	select DRM_PANEL
 	select DRM_PANEL_BRIDGE
diff --git a/drivers/gpu/drm/mxsfb/lcdif_drv.c b/drivers/gpu/drm/mxsfb/lcdif_drv.c
index 8ee00f59ca821..d6a4100e6080a 100644
--- a/drivers/gpu/drm/mxsfb/lcdif_drv.c
+++ b/drivers/gpu/drm/mxsfb/lcdif_drv.c
@@ -17,6 +17,7 @@
 #include <drm/clients/drm_client_setup.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
+#include <drm/drm_bridge_connector.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_encoder.h>
 #include <drm/drm_fbdev_dma.h>
@@ -48,8 +49,10 @@ static const struct drm_encoder_funcs lcdif_encoder_funcs = {
 static int lcdif_attach_bridge(struct lcdif_drm_private *lcdif)
 {
 	struct device *dev = lcdif->drm->dev;
-	struct device_node *ep;
+	struct drm_device *drm = lcdif->drm;
+	struct drm_connector *connector;
 	struct drm_bridge *bridge;
+	struct device_node *ep;
 	int ret;
 
 	for_each_endpoint_of_node(dev->of_node, ep) {
@@ -97,13 +100,30 @@ static int lcdif_attach_bridge(struct lcdif_drm_private *lcdif)
 			return ret;
 		}
 
-		ret = drm_bridge_attach(encoder, bridge, NULL, 0);
+		ret = drm_bridge_attach(encoder, bridge, NULL,
+					DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 		if (ret) {
 			of_node_put(ep);
 			return dev_err_probe(dev, ret,
 					     "Failed to attach bridge for endpoint%u\n",
 					     of_ep.id);
 		}
+
+		connector = drm_bridge_connector_init(drm, encoder);
+		if (IS_ERR(connector)) {
+			of_node_put(ep);
+			return dev_err_probe(drm->dev, PTR_ERR(connector),
+					     "Failed to initialize bridge connector: %pe\n",
+					     connector);
+		}
+
+		ret = drm_connector_attach_encoder(connector, encoder);
+		if (ret < 0) {
+			of_node_put(ep);
+			drm_connector_cleanup(connector);
+			return dev_err_probe(drm->dev, ret,
+					     "Failed to attach encoder.\n");
+		}
 	}
 
 	return 0;
-- 
2.45.2