[RFC PATCH 01/17] drm/exynos: dsi: Convert to bridge driver

[Jagan Teki <jagan@amarulasolutions.com>]

DRM bridge drivers have built-in handling of treating
all display pipeline components as bridges.

Convert exynos_drm_dsi to a bridge driver with built-in
encoder support for compatibility with existing component
drivers.

This keeps switching the driver into the bridge in a more
feasible manner.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/exynos/exynos_drm_dsi.c | 57 +++++++++++++++++--------
 1 file changed, 39 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
index 1d777d8c1a83..90d2ce2c3055 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
@@ -257,6 +257,7 @@ struct exynos_dsi {
 	struct drm_connector connector;
 	struct drm_panel *panel;
 	struct list_head bridge_chain;
+	struct drm_bridge bridge;
 	struct drm_bridge *out_bridge;
 	struct device *dev;
 
@@ -287,9 +288,9 @@ struct exynos_dsi {
 #define host_to_dsi(host) container_of(host, struct exynos_dsi, dsi_host)
 #define connector_to_dsi(c) container_of(c, struct exynos_dsi, connector)
 
-static inline struct exynos_dsi *encoder_to_dsi(struct drm_encoder *e)
+static inline struct exynos_dsi *bridge_to_dsi(struct drm_bridge *b)
 {
-	return container_of(e, struct exynos_dsi, encoder);
+	return container_of(b, struct exynos_dsi, bridge);
 }
 
 enum reg_idx {
@@ -1374,9 +1375,9 @@ static void exynos_dsi_unregister_te_irq(struct exynos_dsi *dsi)
 	}
 }
 
-static void exynos_dsi_enable(struct drm_encoder *encoder)
+static void exynos_dsi_bridge_enable(struct drm_bridge *bridge)
 {
-	struct exynos_dsi *dsi = encoder_to_dsi(encoder);
+	struct exynos_dsi *dsi = bridge_to_dsi(bridge);
 	struct drm_bridge *iter;
 	int ret;
 
@@ -1429,9 +1430,9 @@ static void exynos_dsi_enable(struct drm_encoder *encoder)
 	pm_runtime_put(dsi->dev);
 }
 
-static void exynos_dsi_disable(struct drm_encoder *encoder)
+static void exynos_dsi_bridge_disable(struct drm_bridge *bridge)
 {
-	struct exynos_dsi *dsi = encoder_to_dsi(encoder);
+	struct exynos_dsi *dsi = bridge_to_dsi(bridge);
 	struct drm_bridge *iter;
 
 	if (!(dsi->state & DSIM_STATE_ENABLED))
@@ -1494,9 +1495,9 @@ static const struct drm_connector_helper_funcs exynos_dsi_connector_helper_funcs
 	.get_modes = exynos_dsi_get_modes,
 };
 
-static int exynos_dsi_create_connector(struct drm_encoder *encoder)
+static int exynos_dsi_create_connector(struct exynos_dsi *dsi)
 {
-	struct exynos_dsi *dsi = encoder_to_dsi(encoder);
+	struct drm_encoder *encoder = &dsi->encoder;
 	struct drm_connector *connector = &dsi->connector;
 	struct drm_device *drm = encoder->dev;
 	int ret;
@@ -1522,9 +1523,16 @@ static int exynos_dsi_create_connector(struct drm_encoder *encoder)
 	return 0;
 }
 
-static const struct drm_encoder_helper_funcs exynos_dsi_encoder_helper_funcs = {
-	.enable = exynos_dsi_enable,
-	.disable = exynos_dsi_disable,
+static int exynos_dsi_bridge_attach(struct drm_bridge *bridge,
+				    enum drm_bridge_attach_flags flags)
+{
+	return 0;
+}
+
+static const struct drm_bridge_funcs exynos_dsi_bridge_funcs = {
+	.enable = exynos_dsi_bridge_enable,
+	.disable = exynos_dsi_bridge_disable,
+	.attach = exynos_dsi_bridge_attach,
 };
 
 MODULE_DEVICE_TABLE(of, exynos_dsi_of_match);
@@ -1543,7 +1551,7 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
 		dsi->out_bridge = out_bridge;
 		list_splice_init(&encoder->bridge_chain, &dsi->bridge_chain);
 	} else {
-		int ret = exynos_dsi_create_connector(encoder);
+		int ret = exynos_dsi_create_connector(dsi);
 
 		if (ret) {
 			DRM_DEV_ERROR(dsi->dev,
@@ -1596,7 +1604,7 @@ static int exynos_dsi_host_detach(struct mipi_dsi_host *host,
 
 	if (dsi->panel) {
 		mutex_lock(&drm->mode_config.mutex);
-		exynos_dsi_disable(&dsi->encoder);
+		exynos_dsi_bridge_disable(&dsi->bridge);
 		dsi->panel = NULL;
 		dsi->connector.status = connector_status_disconnected;
 		mutex_unlock(&drm->mode_config.mutex);
@@ -1702,12 +1710,16 @@ static int exynos_dsi_bind(struct device *dev, struct device *master,
 
 	drm_simple_encoder_init(drm_dev, encoder, DRM_MODE_ENCODER_TMDS);
 
-	drm_encoder_helper_add(encoder, &exynos_dsi_encoder_helper_funcs);
-
 	ret = exynos_drm_set_possible_crtcs(encoder, EXYNOS_DISPLAY_TYPE_LCD);
 	if (ret < 0)
 		return ret;
 
+	ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
+	if (ret) {
+		drm_encoder_cleanup(&dsi->encoder);
+		return ret;
+	}
+
 	in_bridge_node = of_graph_get_remote_node(dev->of_node, DSI_PORT_IN, 0);
 	if (in_bridge_node) {
 		in_bridge = of_drm_find_bridge(in_bridge_node);
@@ -1723,10 +1735,9 @@ static void exynos_dsi_unbind(struct device *dev, struct device *master,
 				void *data)
 {
 	struct exynos_dsi *dsi = dev_get_drvdata(dev);
-	struct drm_encoder *encoder = &dsi->encoder;
-
-	exynos_dsi_disable(encoder);
 
+	exynos_dsi_bridge_disable(&dsi->bridge);
+	drm_encoder_cleanup(&dsi->encoder);
 	mipi_dsi_host_unregister(&dsi->dsi_host);
 }
 
@@ -1821,6 +1832,12 @@ static int exynos_dsi_probe(struct platform_device *pdev)
 
 	pm_runtime_enable(dev);
 
+	dsi->bridge.funcs = &exynos_dsi_bridge_funcs;
+	dsi->bridge.of_node = dev->of_node;
+	dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
+
+	drm_bridge_add(&dsi->bridge);
+
 	ret = component_add(dev, &exynos_dsi_component_ops);
 	if (ret)
 		goto err_disable_runtime;
@@ -1835,6 +1852,10 @@ static int exynos_dsi_probe(struct platform_device *pdev)
 
 static int exynos_dsi_remove(struct platform_device *pdev)
 {
+	struct exynos_dsi *dsi = platform_get_drvdata(pdev);
+
+	drm_bridge_remove(&dsi->bridge);
+
 	pm_runtime_disable(&pdev->dev);
 
 	component_del(&pdev->dev, &exynos_dsi_component_ops);
-- 
2.25.1