drm/omap: Add support for drm_panel

Hook up drm_panel support in the omapdrm driver. The change is
relatively simply as the way has been paved by drm_bridge support
already. In addition to looking up, attaching to and detaching from the
panel, we only need to add panel support in the connector .get_modes()
handler, take connector bus flags (set by the panel) into account, and
enable/disable the panel in the encoder enable/disable operations
handlers.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/dss/base.c

@@ -157,7 +157,8 @@ struct omap_dss_device *omapdss_device_next_output(struct omap_dss_device *from)
 			goto done;
 		}
 
-		if (dssdev->id && (dssdev->next || dssdev->bridge))
+		if (dssdev->id &&
+		    (dssdev->next || dssdev->bridge || dssdev->panel))
 			goto done;
 	}
 
@@ -192,10 +193,11 @@ int omapdss_device_connect(struct dss_device *dss,
 	if (!dst) {
 		/*
 		 * The destination is NULL when the source is connected to a
-		 * bridge instead of a DSS device. Stop here, we will attach the
-		 * bridge later when we will have a DRM encoder.
+		 * bridge or panel instead of a DSS device. Stop here, we will
+		 * attach the bridge or panel later when we will have a DRM
+		 * encoder.
 		 */
-		return src && src->bridge ? 0 : -EINVAL;
+		return src && (src->bridge || src->panel) ? 0 : -EINVAL;
 	}
 
 	if (omapdss_device_is_connected(dst))
@@ -223,7 +225,7 @@ void omapdss_device_disconnect(struct omap_dss_device *src,
 		dst ? dev_name(dst->dev) : "NULL");
 
 	if (!dst) {
-		WARN_ON(!src->bridge);
+		WARN_ON(!src->bridge && !src->panel);
 		return;
 	}
 

drivers/gpu/drm/omapdrm/dss/omapdss.h

@@ -411,6 +411,7 @@ struct omap_dss_device {
 	struct dss_device *dss;
 	struct omap_dss_device *next;
 	struct drm_bridge *bridge;
+	struct drm_panel *panel;
 
 	struct list_head list;
 

drivers/gpu/drm/omapdrm/dss/output.c

@@ -22,6 +22,8 @@
 #include <linux/of.h>
 #include <linux/of_graph.h>
 
+#include <drm/drm_panel.h>
+
 #include "dss.h"
 #include "omapdss.h"
 
@@ -37,6 +39,9 @@ int omapdss_device_init_output(struct omap_dss_device *out)
 
 	out->next = omapdss_find_device_by_node(remote_node);
 	out->bridge = of_drm_find_bridge(remote_node);
+	out->panel = of_drm_find_panel(remote_node);
+	if (IS_ERR(out->panel))
+		out->panel = NULL;
 
 	of_node_put(remote_node);
 
@@ -47,7 +52,7 @@ int omapdss_device_init_output(struct omap_dss_device *out)
 		return -EINVAL;
 	}
 
-	return out->next || out->bridge ? 0 : -EPROBE_DEFER;
+	return out->next || out->bridge || out->panel ? 0 : -EPROBE_DEFER;
 }
 EXPORT_SYMBOL(omapdss_device_init_output);
 

drivers/gpu/drm/omapdrm/omap_connector.c

@@ -17,6 +17,7 @@
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc.h>
+#include <drm/drm_panel.h>
 #include <drm/drm_probe_helper.h>
 
 #include "omap_drv.h"
@@ -211,6 +212,7 @@ static int omap_connector_get_modes_edid(struct drm_connector *connector,
 
 static int omap_connector_get_modes(struct drm_connector *connector)
 {
+	struct omap_connector *omap_connector = to_omap_connector(connector);
 	struct omap_dss_device *dssdev;
 
 	DBG("%s", connector->name);
@@ -233,6 +235,13 @@ static int omap_connector_get_modes(struct drm_connector *connector)
 	if (dssdev)
 		return dssdev->ops->get_modes(dssdev, connector);
 
+	/*
+	 * Otherwise if the display pipeline uses a drm_panel, we delegate the
+	 * operation to the panel API.
+	 */
+	if (omap_connector->output->panel)
+		return drm_panel_get_modes(omap_connector->output->panel);
+
 	/*
 	 * We can't retrieve modes, which can happen for instance for a DVI or
 	 * VGA output with the DDC bus unconnected. The KMS core will add the

drivers/gpu/drm/omapdrm/omap_drv.c

@@ -23,6 +23,7 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_probe_helper.h>
+#include <drm/drm_panel.h>
 
 #include "omap_dmm_tiler.h"
 #include "omap_drv.h"
@@ -137,6 +138,9 @@ static void omap_disconnect_pipelines(struct drm_device *ddev)
 	for (i = 0; i < priv->num_pipes; i++) {
 		struct omap_drm_pipeline *pipe = &priv->pipes[i];
 
+		if (pipe->output->panel)
+			drm_panel_detach(pipe->output->panel);
+
 		omapdss_device_disconnect(NULL, pipe->output);
 
 		omapdss_device_put(pipe->output);
@@ -214,13 +218,15 @@ static int omap_display_id(struct omap_dss_device *output)
 		display = omapdss_display_get(output);
 		node = display->dev->of_node;
 		omapdss_device_put(display);
-	} else {
+	} else if (output->bridge) {
 		struct drm_bridge *bridge = output->bridge;
 
 		while (bridge->next)
 			bridge = bridge->next;
 
 		node = bridge->of_node;
+	} else if (output->panel) {
+		node = output->panel->dev->of_node;
 	}
 
 	return node ? of_alias_get_id(node, "display") : -ENODEV;
@@ -335,6 +341,13 @@ static int omap_modeset_init(struct drm_device *dev)
 				return -ENOMEM;
 
 			drm_connector_attach_encoder(pipe->connector, encoder);
+
+			if (pipe->output->panel) {
+				ret = drm_panel_attach(pipe->output->panel,
+						       pipe->connector);
+				if (ret < 0)
+					return ret;
+			}
 		}
 
 		crtc = omap_crtc_init(dev, pipe, priv->planes[i]);

drivers/gpu/drm/omapdrm/omap_encoder.c

@@ -20,6 +20,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_modeset_helper_vtables.h>
 #include <drm/drm_edid.h>
+#include <drm/drm_panel.h>
 
 #include "omap_drv.h"
 
@@ -79,22 +80,15 @@ static void omap_encoder_update_videomode_flags(struct videomode *vm,
 	}
 }
 
-static void omap_encoder_hdmi_mode_set(struct drm_encoder *encoder,
+static void omap_encoder_hdmi_mode_set(struct drm_connector *connector,
+				       struct drm_encoder *encoder,
 				       struct drm_display_mode *adjusted_mode)
 {
-	struct drm_device *dev = encoder->dev;
 	struct omap_encoder *omap_encoder = to_omap_encoder(encoder);
 	struct omap_dss_device *dssdev = omap_encoder->output;
-	struct drm_connector *connector;
 	bool hdmi_mode;
 
-	hdmi_mode = false;
-	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
-		if (connector->encoder == encoder) {
-			hdmi_mode = omap_connector_get_hdmi_mode(connector);
-			break;
-		}
-	}
+	hdmi_mode = omap_connector_get_hdmi_mode(connector);
 
 	if (dssdev->ops->hdmi.set_hdmi_mode)
 		dssdev->ops->hdmi.set_hdmi_mode(dssdev, hdmi_mode);
@@ -117,8 +111,16 @@ static void omap_encoder_mode_set(struct drm_encoder *encoder,
 	struct omap_encoder *omap_encoder = to_omap_encoder(encoder);
 	struct omap_dss_device *output = omap_encoder->output;
 	struct omap_dss_device *dssdev;
+	struct drm_device *dev = encoder->dev;
+	struct drm_connector *connector;
 	struct drm_bridge *bridge;
 	struct videomode vm = { 0 };
+	u32 bus_flags;
+
+	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+		if (connector->encoder == encoder)
+			break;
+	}
 
 	drm_display_mode_to_videomode(adjusted_mode, &vm);
 
@@ -135,8 +137,6 @@ static void omap_encoder_mode_set(struct drm_encoder *encoder,
 		omap_encoder_update_videomode_flags(&vm, dssdev->bus_flags);
 
 	for (bridge = output->bridge; bridge; bridge = bridge->next) {
-		u32 bus_flags;
-
 		if (!bridge->timings)
 			continue;
 
@@ -144,6 +144,9 @@ static void omap_encoder_mode_set(struct drm_encoder *encoder,
 		omap_encoder_update_videomode_flags(&vm, bus_flags);
 	}
 
+	bus_flags = connector->display_info.bus_flags;
+	omap_encoder_update_videomode_flags(&vm, bus_flags);
+
 	/* Set timings for all devices in the display pipeline. */
 	dss_mgr_set_timings(output, &vm);
 
@@ -154,7 +157,7 @@ static void omap_encoder_mode_set(struct drm_encoder *encoder,
 
 	/* Set the HDMI mode and HDMI infoframe if applicable. */
 	if (output->type == OMAP_DISPLAY_TYPE_HDMI)
-		omap_encoder_hdmi_mode_set(encoder, adjusted_mode);
+		omap_encoder_hdmi_mode_set(connector, encoder, adjusted_mode);
 }
 
 static void omap_encoder_disable(struct drm_encoder *encoder)
@@ -165,6 +168,12 @@ static void omap_encoder_disable(struct drm_encoder *encoder)
 
 	dev_dbg(dev->dev, "disable(%s)\n", dssdev->name);
 
+	/* Disable the panel if present. */
+	if (dssdev->panel) {
+		drm_panel_disable(dssdev->panel);
+		drm_panel_unprepare(dssdev->panel);
+	}
+
 	/*
 	 * Disable the chain of external devices, starting at the one at the
 	 * internal encoder's output.
@@ -214,6 +223,12 @@ static void omap_encoder_enable(struct drm_encoder *encoder)
 	 * internal encoder's output.
 	 */
 	omapdss_device_enable(dssdev->next);
+
+	/* Enable the panel if present. */
+	if (dssdev->panel) {
+		drm_panel_prepare(dssdev->panel);
+		drm_panel_enable(dssdev->panel);
+	}
 }
 
 static int omap_encoder_atomic_check(struct drm_encoder *encoder,