drm: exynos: dsi: Use drm panel_bridge API

Replace the manual panel handling code by a drm panel_bridge via
devm_drm_of_get_bridge().

Adding panel_bridge handling,

- Drops drm_connector and related operations as drm_bridge_attach
  creates connector during attachment.

- Drops panel pointer and iterate the bridge, so-that it can operate
  the normal bridge and panel_bridge in constitutive callbacks.

This simplifies the driver and allows all components in the display
pipeline to be treated as bridges.
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220303163654.3381470-5-jagan@amarulasolutions.com

drivers/gpu/drm/exynos/exynos_drm_dsi.c

@@ -24,9 +24,7 @@
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
-#include <drm/drm_fb_helper.h>
 #include <drm/drm_mipi_dsi.h>
-#include <drm/drm_panel.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_simple_kms_helper.h>
@@ -253,8 +251,6 @@ struct exynos_dsi_driver_data {
 struct exynos_dsi {
 	struct drm_encoder encoder;
 	struct mipi_dsi_host dsi_host;
-	struct drm_connector connector;
-	struct drm_panel *panel;
 	struct list_head bridge_chain;
 	struct drm_bridge *out_bridge;
 	struct device *dev;
@@ -285,7 +281,6 @@ 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)
 {
@@ -1380,42 +1375,21 @@ static void exynos_dsi_enable(struct drm_encoder *encoder)
 
 	dsi->state |= DSIM_STATE_ENABLED;
 
-	if (dsi->panel) {
-		ret = drm_panel_prepare(dsi->panel);
-		if (ret < 0)
-			goto err_put_sync;
-	} else {
-		list_for_each_entry_reverse(iter, &dsi->bridge_chain,
-					    chain_node) {
-			if (iter->funcs->pre_enable)
-				iter->funcs->pre_enable(iter);
-		}
+	list_for_each_entry_reverse(iter, &dsi->bridge_chain, chain_node) {
+		if (iter->funcs->pre_enable)
+			iter->funcs->pre_enable(iter);
 	}
 
 	exynos_dsi_set_display_mode(dsi);
 	exynos_dsi_set_display_enable(dsi, true);
 
-	if (dsi->panel) {
-		ret = drm_panel_enable(dsi->panel);
-		if (ret < 0)
-			goto err_display_disable;
-	} else {
-		list_for_each_entry(iter, &dsi->bridge_chain, chain_node) {
-			if (iter->funcs->enable)
-				iter->funcs->enable(iter);
-		}
+	list_for_each_entry(iter, &dsi->bridge_chain, chain_node) {
+		if (iter->funcs->enable)
+			iter->funcs->enable(iter);
 	}
 
 	dsi->state |= DSIM_STATE_VIDOUT_AVAILABLE;
 	return;
-
-err_display_disable:
-	exynos_dsi_set_display_enable(dsi, false);
-	drm_panel_unprepare(dsi->panel);
-
-err_put_sync:
-	dsi->state &= ~DSIM_STATE_ENABLED;
-	pm_runtime_put(dsi->dev);
 }
 
 static void exynos_dsi_disable(struct drm_encoder *encoder)
@@ -1428,15 +1402,12 @@ static void exynos_dsi_disable(struct drm_encoder *encoder)
 
 	dsi->state &= ~DSIM_STATE_VIDOUT_AVAILABLE;
 
-	drm_panel_disable(dsi->panel);
-
 	list_for_each_entry_reverse(iter, &dsi->bridge_chain, chain_node) {
 		if (iter->funcs->disable)
 			iter->funcs->disable(iter);
 	}
 
 	exynos_dsi_set_display_enable(dsi, false);
-	drm_panel_unprepare(dsi->panel);
 
 	list_for_each_entry(iter, &dsi->bridge_chain, chain_node) {
 		if (iter->funcs->post_disable)
@@ -1456,70 +1427,6 @@ static void exynos_dsi_mode_set(struct drm_encoder *encoder,
 	drm_mode_copy(&dsi->mode, adjusted_mode);
 }
 
-static enum drm_connector_status
-exynos_dsi_detect(struct drm_connector *connector, bool force)
-{
-	return connector->status;
-}
-
-static void exynos_dsi_connector_destroy(struct drm_connector *connector)
-{
-	drm_connector_unregister(connector);
-	drm_connector_cleanup(connector);
-	connector->dev = NULL;
-}
-
-static const struct drm_connector_funcs exynos_dsi_connector_funcs = {
-	.detect = exynos_dsi_detect,
-	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = exynos_dsi_connector_destroy,
-	.reset = drm_atomic_helper_connector_reset,
-	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
-	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
-};
-
-static int exynos_dsi_get_modes(struct drm_connector *connector)
-{
-	struct exynos_dsi *dsi = connector_to_dsi(connector);
-
-	if (dsi->panel)
-		return drm_panel_get_modes(dsi->panel, connector);
-
-	return 0;
-}
-
-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)
-{
-	struct exynos_dsi *dsi = encoder_to_dsi(encoder);
-	struct drm_connector *connector = &dsi->connector;
-	struct drm_device *drm = encoder->dev;
-	int ret;
-
-	connector->polled = DRM_CONNECTOR_POLL_HPD;
-
-	ret = drm_connector_init(drm, connector, &exynos_dsi_connector_funcs,
-				 DRM_MODE_CONNECTOR_DSI);
-	if (ret) {
-		DRM_DEV_ERROR(dsi->dev,
-			      "Failed to initialize connector with drm\n");
-		return ret;
-	}
-
-	connector->status = connector_status_disconnected;
-	drm_connector_helper_add(connector, &exynos_dsi_connector_helper_funcs);
-	drm_connector_attach_encoder(connector, encoder);
-	if (!drm->registered)
-		return 0;
-
-	connector->funcs->reset(connector);
-	drm_connector_register(connector);
-	return 0;
-}
-
 static const struct drm_encoder_helper_funcs exynos_dsi_encoder_helper_funcs = {
 	.enable = exynos_dsi_enable,
 	.disable = exynos_dsi_disable,
@@ -1532,33 +1439,23 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
 				  struct mipi_dsi_device *device)
 {
 	struct exynos_dsi *dsi = host_to_dsi(host);
+	struct device *dev = dsi->dev;
 	struct drm_encoder *encoder = &dsi->encoder;
 	struct drm_device *drm = encoder->dev;
-	struct drm_bridge *out_bridge;
-
-	out_bridge  = of_drm_find_bridge(device->dev.of_node);
-	if (out_bridge) {
-		drm_bridge_attach(encoder, out_bridge, NULL, 0);
-		dsi->out_bridge = out_bridge;
-		list_splice_init(&encoder->bridge_chain, &dsi->bridge_chain);
-	} else {
-		int ret = exynos_dsi_create_connector(encoder);
-
-		if (ret) {
-			DRM_DEV_ERROR(dsi->dev,
-				      "failed to create connector ret = %d\n",
-				      ret);
-			drm_encoder_cleanup(encoder);
-			return ret;
-		}
+	int ret;
 
-		dsi->panel = of_drm_find_panel(device->dev.of_node);
-		if (IS_ERR(dsi->panel))
-			dsi->panel = NULL;
-		else
-			dsi->connector.status = connector_status_connected;
+	dsi->out_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
+	if (IS_ERR(dsi->out_bridge)) {
+		ret = PTR_ERR(dsi->out_bridge);
+		DRM_DEV_ERROR(dev, "failed to find the bridge: %d\n", ret);
+		return ret;
 	}
 
+	DRM_DEV_INFO(dev, "Attached %s device\n", device->name);
+
+	drm_bridge_attach(encoder, dsi->out_bridge, NULL, 0);
+	list_splice_init(&encoder->bridge_chain, &dsi->bridge_chain);
+
 	/*
 	 * This is a temporary solution and should be made by more generic way.
 	 *
@@ -1566,7 +1463,7 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
 	 * TE interrupt handler.
 	 */
 	if (!(device->mode_flags & MIPI_DSI_MODE_VIDEO)) {
-		int ret = exynos_dsi_register_te_irq(dsi, &device->dev);
+		ret = exynos_dsi_register_te_irq(dsi, &device->dev);
 		if (ret)
 			return ret;
 	}
@@ -1593,18 +1490,10 @@ static int exynos_dsi_host_detach(struct mipi_dsi_host *host,
 	struct exynos_dsi *dsi = host_to_dsi(host);
 	struct drm_device *drm = dsi->encoder.dev;
 
-	if (dsi->panel) {
-		mutex_lock(&drm->mode_config.mutex);
-		exynos_dsi_disable(&dsi->encoder);
-		dsi->panel = NULL;
-		dsi->connector.status = connector_status_disconnected;
-		mutex_unlock(&drm->mode_config.mutex);
-	} else {
-		if (dsi->out_bridge->funcs->detach)
-			dsi->out_bridge->funcs->detach(dsi->out_bridge);
-		dsi->out_bridge = NULL;
-		INIT_LIST_HEAD(&dsi->bridge_chain);
-	}
+	if (dsi->out_bridge->funcs->detach)
+		dsi->out_bridge->funcs->detach(dsi->out_bridge);
+	dsi->out_bridge = NULL;
+	INIT_LIST_HEAD(&dsi->bridge_chain);
 
 	if (drm->mode_config.poll_enabled)
 		drm_kms_helper_hotplug_event(drm);