drm: bridge: Link encoder and bridge in core code

Instead of linking encoders and bridges in every driver (and getting it
wrong half of the time, as many drivers forget to set the drm_bridge
encoder pointer), do so in core code. The drm_bridge_attach() function
needs the encoder and optional previous bridge to perform that task,
update all the callers.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Stefan Agner <stefan@agner.ch> # For DCU
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> # For atmel-hlcdc
Acked-by: Vincent Abriou <vincent.abriou@st.com> # For STI
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> # For sun4i
Acked-by: Xinliang Liu <z.liuxinliang@hisilicon.com> # For hisilicon
Acked-by: Jyri Sarha <jsarha@ti.com> # For tilcdc
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1481709550-29226-4-git-send-email-laurent.pinchart+renesas@ideasonboard.com

3 files changed, 13 insertions, 30 deletions

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 90fb831ef031..3bd3bd688d1a 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -63,6 +63,7 @@ enum mtk_dpi_out_color_format {
 struct mtk_dpi {
 	struct mtk_ddp_comp ddp_comp;
 	struct drm_encoder encoder;
+	struct drm_bridge *bridge;
 	void __iomem *regs;
 	struct device *dev;
 	struct clk *engine_clk;
@@ -620,8 +621,7 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
 	/* Currently DPI0 is fixed to be driven by OVL1 */
 	dpi->encoder.possible_crtcs = BIT(1);
 
-	dpi->encoder.bridge->encoder = &dpi->encoder;
-	ret = drm_bridge_attach(dpi->encoder.dev, dpi->encoder.bridge);
+	ret = drm_bridge_attach(&dpi->encoder, dpi->bridge, NULL);
 	if (ret) {
 		dev_err(dev, "Failed to attach bridge: %d\n", ret);
 		goto err_cleanup;
@@ -718,9 +718,9 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 
 	dev_info(dev, "Found bridge node: %s\n", bridge_node->full_name);
 
-	dpi->encoder.bridge = of_drm_find_bridge(bridge_node);
+	dpi->bridge = of_drm_find_bridge(bridge_node);
 	of_node_put(bridge_node);
-	if (!dpi->encoder.bridge)
+	if (!dpi->bridge)
 		return -EPROBE_DEFER;
 
 	comp_id = mtk_ddp_comp_get_id(dev->of_node, MTK_DPI);
diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 2c42f90809d8..dd71cbb1a622 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -622,26 +622,6 @@ static const struct drm_connector_helper_funcs
 	.get_modes = mtk_dsi_connector_get_modes,
 };
 
-static int mtk_drm_attach_bridge(struct drm_bridge *bridge,
-				 struct drm_encoder *encoder)
-{
-	int ret;
-
-	if (!bridge)
-		return -ENOENT;
-
-	encoder->bridge = bridge;
-	bridge->encoder = encoder;
-	ret = drm_bridge_attach(encoder->dev, bridge);
-	if (ret) {
-		DRM_ERROR("Failed to attach bridge to drm\n");
-		encoder->bridge = NULL;
-		bridge->encoder = NULL;
-	}
-
-	return ret;
-}
-
 static int mtk_dsi_create_connector(struct drm_device *drm, struct mtk_dsi *dsi)
 {
 	int ret;
@@ -692,8 +672,10 @@ static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi)
 	dsi->encoder.possible_crtcs = 1;
 
 	/* If there's a bridge, attach to it and let it create the connector */
-	ret = mtk_drm_attach_bridge(dsi->bridge, &dsi->encoder);
+	ret = drm_bridge_attach(&dsi->encoder, dsi->bridge, NULL);
 	if (ret) {
+		DRM_ERROR("Failed to attach bridge to drm\n");
+
 		/* Otherwise create our own connector and attach to a panel */
 		ret = mtk_dsi_create_connector(drm, dsi);
 		if (ret)
diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
index 0e8c4d9af340..c26251260b83 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
@@ -149,6 +149,7 @@ struct hdmi_audio_param {
 
 struct mtk_hdmi {
 	struct drm_bridge bridge;
+	struct drm_bridge *next_bridge;
 	struct drm_connector conn;
 	struct device *dev;
 	struct phy *phy;
@@ -1314,9 +1315,9 @@ static int mtk_hdmi_bridge_attach(struct drm_bridge *bridge)
 		return ret;
 	}
 
-	if (bridge->next) {
-		bridge->next->encoder = bridge->encoder;
-		ret = drm_bridge_attach(bridge->encoder->dev, bridge->next);
+	if (hdmi->next_bridge) {
+		ret = drm_bridge_attach(bridge->encoder, hdmi->next_bridge,
+					bridge);
 		if (ret) {
 			dev_err(hdmi->dev,
 				"Failed to attach external bridge: %d\n", ret);
@@ -1510,8 +1511,8 @@ static int mtk_hdmi_dt_parse_pdata(struct mtk_hdmi *hdmi,
 	of_node_put(ep);
 
 	if (!of_device_is_compatible(remote, "hdmi-connector")) {
-		hdmi->bridge.next = of_drm_find_bridge(remote);
-		if (!hdmi->bridge.next) {
+		hdmi->next_bridge = of_drm_find_bridge(remote);
+		if (!hdmi->next_bridge) {
 			dev_err(dev, "Waiting for external bridge\n");
 			of_node_put(remote);
 			return -EPROBE_DEFER;